462nd Meeting - May 5, 1999
UNITED STATES OF AMERICA
NUCLEAR REGULATORY COMMISSION
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
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462ND ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
(ACRS)
***
USNRC
11545 Rockville Pike, Room T-2B3
Rockville, Maryland
Wednesday, May 5, 1999
The subcommittee met pursuant to notice, at 1:05 p.m.
MEMBERS PRESENT:
DANA POWERS, Chairman, ACRS
GEORGE APOSTOLAKIS, Member, ACRS
JOHN BARTON, Member, ACRS
MARIO FONTANA, Member, ACRS
THOMAS KRESS, Member, ACRS
DON MILLER, Member, ACRS
ROBERT SEALE, Member, ACRS
WILLIAM SHACK, Member, ACRS
GRAHAM WALLIS, Member, ACRS
MARIO V. BONACA, Member, ACRS
ROBERT E. UHRIG, Member, ACRS. P R O C E E D I N G S
[1:05 p.m.]
DR. POWERS: The meeting will now come to order. This is
the first day of the 462nd of the Advisory Committee on Reactor
Safeguards. During today's meeting, the committee will cover the
following: Electric Power Research Institute application of
risk-informed methods to in-service inspection; proposed final revision
to 10 CFR 50.59; safety evaluation for the Calvert Cliffs Nuclear Power
Plant license renewal application.
The meeting is being conducted in accordance with the
provisions of the Federal Advisory Committee Act. Dr. John T. Larkins
is the designated Federal official for the initial portion of the
meeting.
We have received no written statements or requests for time
to make oral statements from members of the public regarding today's
session. A transcript of portions of the meeting is being kept, and it
is requested that speakers use one of the microphones, identify
themselves, and speak with sufficient clarity and volume so they can be
readily heard.
Now let me begin with a few items of interest. One of the
item that may most interest the members of this committee is that a
proposed new member, Jack Siebert, who I believe is in the audience --
Jack?
I think many of you have had a chance to meet and talk to
Jack. He has an impressive resume of credentials of experience within
the nuclear power industry and now has his own company.
Tom, you might be particularly interested in his experience
at Prairie Island.
DR. KRESS: Oh. Yes.
DR. POWERS: And so I think he brings a wealth of experience
to the committee.
DR. APOSTOLAKIS: You mean Dr. Wallis will not be the junior
member anymore?
[Laughter.]
DR. POWERS: Now, we may reserve that place for Dr. Wallis
especially.
DR. APOSTOLAKIS: Oh. Bonaca. I'm sorry. I'm sorry.
[Laughter.]
DR. POWERS: No, I think we'll reserve it for Dr. Wallis. I
think he'll be the permanent junior member.
[Laughter.]
DR. POWERS: For those of us who lived through it, I see
that Millstone II has been approved for restart, that the Clinton plant
is making significant progress toward restart. And again for Dr. Kress,
I note the Commission is considering revisions to the KI policies.
With those items of interest, I'll ask if any of the members
have items that they would like to bring up at this time?
Seeing none, I think we'll turn to the first of our topics,
which is the application of risk-informed methods to in-service
inspection. Dr. Shack, I believe you are the cognizant member in that
area.
DR. SHACK: Yes. We reviewed the EPRI application of
risk-informed methods to in-service inspection this morning, and Mr.
Mitman is going to give us a few highlights of this morning's discussion
and presentation.
MR. MITMAN: Good afternoon. My name is Jeff Mitman, I'm
the EPRI project manager on risk-informed ISI.
I'm going to go -- I have an overview presentation this
afternoon that will highlight some of the things that we talked about
this morning.
I will say that the various individuals involved with the
discussions this morning on the EPRI project team are still available
for questions, so if I'm unable to answer your questions, we'll ask them
to come to the microphone and answer your questions.
The objective of the discussions between the EPRI team and
the ACRS are to facilitate review in concurrence the EPRI methodology to
support an SER in September of this year. What I'll talk about this
afternoon is a little bit about the topical status, a little bit about
the pilot plant status, a very short presentation on the methodology
itself, and then some summary and concluding remarks.
The topical has been revised and submitted to the NRC in
June of this -- or, excuse me, let me back up. The original topical was
submitted to the NRC in June of 1996. We received RAIs on that in 1997.
The RAIs were responded to in 1998 after we had completed a couple of
the pilots and done some additional research. That information, along
with an enhanced description of the bases and the procedure, lessons
learned from the pilots and resolutions of questions and comments from
the NRC RAIs, along with related EPRI research, were all rolled into the
revised topical, which the ACRS members should have a copy of.
The expectations are to receive -- for the staff, the NRC
staff to write a draft SER in the middle of June of this year, and our
hope is to have an SER from the NRC by the end of September of this
year.
The pilot plants, there are two slight variations to the
methodology. One applies ASME code case N-560 and the other N-578. The
N-560 approach is applied only to class 1, while N-578 can be applied to
class 1, 2, 3 and non-code piping.
The first plant to be submitted was Vermont Yankee, which is
a class 1 submittal. It was the first plant to receive an SER in the
risk-informed ISI arena.
The ANO2 was also submitted last year. It received an SER
in December of last year and that's a full plant submittal.
ANO1, which is a class 1 submittal, was submitted back
mid-year last year. We're currently in the process of answering RAIs
from the staff, and those should go into the -- back to the staff in a
week or so.
Fitzpatrick is the other full plant submittal. That's 14
systems. Final submittal preparation is in progress. The work is
essentially complete with the exception of putting the submittal
together.
Braidwood in the final four plant pilots are all class 1
only applications. Braidwood, a Westinghouse unit, is about 80 percent
complete. South Texas is approximately 75 percent complete. That's
also a Westinghouse unit. And Riverbend and Waterford are planned for
the second half of this year.
A short discussion of the methodology itself. The first
task is to determine the scope, whether we want to do class 1, class 1,
2, 3, where the system boundaries are, that type of thing. The two
major tasks in the methodology are consequence analysis and a
degradation analysis. Those take up approximately 50 to 50 percent of
the total time involved with it. They're independent processes that can
be done simultaneously or one before the other.
Once those tasks are completed, we take a second look at
plant-specific service experience. We then categorize our segments into
-- or our welds into risk regions on our risk matrix. We then pick
individual locations for inspection, along with picking the individual
inspection methodologies.
Coming out of that, we do a risk impact assessment and then
we finalize the program. There are two feedback loops, one coming out
of the risk impact assessment, that if we determine the risk impact is
unacceptable, we can go back and re-assign or add elements to ensure
that the risk impact is acceptable. And there is also a feedback loop
coming out of the bottom of the process where we monitor the plant,
monitor what's going on in the industry with damage mechanisms to ensure
that the individual plant and the process are modified appropriately
based on new experience.
The final slide I have is a slide of summaries and
conclusions. The revised topical has been submitted. It addresses
questions and comments raised by the NRC staff. It's in compliance with
Reg Guide 1.174 and Reg Guide 1.178. The methodology has been applied
to a broad range of plants -- GE, Westinghouse, B&W and CE plants; it's
been applied it multiple architect engineers, and we have applied it
both in the full scope and partial scope applications.
One of the big drivers to this is that it allows for
significant decrease in rem exposure to the plant staff.
And finally, the pilots and the research that's been done
supports the conclusion of a negligible impact on risk.
DR. SHACK: What's an estimated cost for the implementation
of a plan like this?
MR. MITMAN: It's fairly straightforward to cost out a class
1 only application. Approximately cost is about 150,000 dollars. When
you go to a full plant implementation, it's not as easy to delineate
because, one, you have to tell -- you have to decide what the scope is;
and depending on how you look at it, the scope, you know, the scope is
not clearly defined. The estimate is around three times the cost of a
class 1 only implementation.
DR. POWERS: What drives the cost?
MR. MITMAN: What drives the cost? The reason the costs are
so much higher on class -- on a full plant implementation are -- there
are two reasons: one, the number of inspections that you're looking at
is three or four times higher. Also, with the class 1 implementation,
most of the analysis is inside containment where we've already taken
into consideration -- or the design is already taken into consideration
spacial effects. You get out into class 2 and class 3, you break a pipe
in-service water or CCW, it can go off and affect other systems. So we
have to do a lot more work, a lot more tension to cross system analysis.
DR. POWERS: System interactions and whatnot.
MR. MITMAN: Yes.
DR. POWERS: What drives the risk? You said it was a
negligible increase in risk.
MR. MITMAN: Because of the implementation of the program?
DR. POWERS: Uh-huh.
MR. MITMAN: We've done analysis where we can show that
eliminating all the inspections has negligible impact on risk, so by
changing the inspection locations and optimizing them on risk, typically
we're seeing a small improvement on risk. But the probability of
failure of the piping systems is fairly low to begin with.
DR. POWERS: The fact that you can eliminate all the
inspections and not make any impact on risk, is that a statement
concerning the reality of the reliability of piping, or is it a
statement that deals with the inadequacies of the risk assessment tools?
MR. MITMAN: It has to do with the -- the piping is very
reliable. The typical failure frequencies that we're seeing on an
individual weld are -- I think the highs are in the neighborhood of 1E
to the minus 4 on a weld, and to goes down from there, probably averages
per weld around 1E to minus 5, 1E to the minus 6. So the piping is
already very reliable.
As far as the accuracy of the PSA and its ability to answer
the questions, we've done quite a bit of uncertainty analysis and we
feel very comfortable that even though there is significant uncertainty
in the question -- in the answers, that the answers are -- we're erring
in the conservative direction and we're not significantly
underestimating the risk.
DR. POWERS: We've seen a lot of components within the
plant, and to be discovering degradation mechanisms with nice little
three-word -- three- or four-letter, five-letter, six-letter
initialisms, depending on what variations of stress corrosion cracking
you're talking about, how do the PRAs accommodate the possibility of
heretofore undiscovered but feasible degradation mechanisms affecting
pipes?
MR. MITMAN: The EPRI methodology is based upon service
experience, so we're not trying to predict a new damage mechanism that
we haven't seen in the past; therefore, any new damage mechanism that
would appear would -- is planned to be caught by this feedback loop that
we've got in the process. We'll continue to monitor what's going on in
the industry and capture insights that way. We're not trying to predict
a new damage mechanism.
DR. POWERS: It seems to me lots of the corrosion effects,
degradation of piping due to corrosion, are very, very sensitive to the
water chemistry.
It seems to me that there are lots of opportunities for
human error in adjusting that water chemistry. Why doesn't -- is that
the common mode failure mechanism that comes in, human error and water
chemistry?
MR. MITMAN: Water chemistry is certainly taken into
consideration as part of the analysis. Each of the damage mechanisms
has laid out deterministic criteria that looks at water chemistry and
operating condition of the piping, and out of that comes susceptibility
determination for that damage mechanism on the appropriate piping. So
in that sense, it is considered. It's not rolled back into the
consequence analysis. The consequence analysis is a conditional core
damage probability that assumes that that pipe segment fails.
DR. POWERS: I guess what I'm asking is, what is the
likelihood that you have a human error that results in an inappropriate
water chemistry in the plant that leads to corrosion, and how do you
take that into account in the PRA?
MR. MITMAN: We haven't looked at the probability of acts of
omission or acts of commission in the operation of the plant. It is not
factored into the PRA analysis that's done. There is a feedback on
operating conditions into the degradation analysis, though there is no
-- there is no attempt to identify lack -- or acts of commission or acts
of omission in it.
DR. POWERS: I guess I don't understand how you can do a
risk analysis without taking that kind of human error rate into account.
MR. MITMAN: I'd like to get a response from one of the team
members on that.
MR. FLEMING: This is Karl Fleming from ERIN Engineering. I
think the answer to the question is that in the EPRI methodology, the
PRA is not used as a tool to estimate the likelihood of pipe ruptures.
The tools that are used to estimate the likelihood of pipe ruptures is
to deterministically examine the physical conditions necessary for
degradation mechanisms. The PRA is used to evaluate the consequences of
pipe rupture in terms of given that pipe rupture is assumed to occur,
what would be the consequences in terms of operability of plant
equipment and flooding effects and so forth on the plant.
So we don't really try to use the PRA to predict the
likelihood that human errors create piping conditions; however,
human-induced -- human-caused failures are evident in the service
experience. When you look at the service experience of piping failures,
you know, there are some events that are attributed to human error.
DR. APOSTOLAKIS: But let me follow up with a question. The
question I thought -- part of the question was whether, if you ever come
across failure, in which case you could have more than one segment
affected by the mechanism, in which case, your estimation of the
consequences would take that into account.
You put down individual segments, not combinations; is that
correct? Is it possible to have only one?
MR. FLEMING: Well, if there was a single problem that was
creating the physical conditions for damage mechanisms in two or more
segments, they're going to be separately picked up. So if there was a
--
DR. APOSTOLAKIS: A common combination.
MR. FLEMING: Well, they're going to be separately analyzed,
and if it turns out that there is some root cause that's creating many
segments to have a susceptibility to a damage mechanism, that would be
identified in the analysis. But it's identified in a deterministic way,
not a probabilistic way.
DR. POWERS: I guess I'm still a little perplexed. Could we
go back to your viewgraph where you mentioned there is no change in
risk. Maybe I didn't understand well what the significance of that
statement is. You said this supports the conclusion of the negligible
risk impact. Maybe I don't understand what you're trying to say there.
MR. MITMAN: What we're trying to say with that statement is
that by going from the current ASME Section 11 requirements to the
risk-informed implementation, you do not see a significant change in
risk because of that move neither up nor down. There tends to be a
small decrease in risk because we're applying the inspections more -- in
areas where they're more risk-significant; however, because of changing
from ASME Section 11 requirements to the risk-informed requirements,
there is no increase -- no significant increase in risk, and typically
it's a decrease.
DR. POWERS: I guess I am not grasping the risk here. You
have said that you use the PRA to assess the consequences, and what I
think one would like to know here is what the change in probability of
rupture times those consequences would be.
MR. MITMAN: You are correct. The original analysis or the
flow chart of the analysis shows a consequence analysis there that's
looking at conditional core damage probability and conditional large
early release probability. However, down at the bottom is a risk-impact
assessment that's being performed, and out of that risk-impact
assessment we gather the evidence to be able to make that claim.
DR. POWERS: But this risk assessment that you've done,
despite the operational experience that human errors can cause
degradation, doesn't address that aspect. It's just not taken into
account.
MR. MITMAN: The impact of -- I'll have Vesna address that.
MS. DIMITRIJEVIC: Well, Karl already talked about that, and
I just want to point out, and if you put the risk matrix, maybe that
will help us in the discussion.
The consequence analysis and degradation analysis in this
matrix which determine leaks are done completely independently. So the
consequence analysis from the plant's point has all the human reactions
which the plant needs to survive accidents given the pipe break.
Now when it comes to the human action which creates or can
influence pipe breaks, that analysis wasn't done specifically, because
we assume that that was already included in the data which we look in.
So whatever degradation which we have, if there is a human action which
contributes to this likelihood, that was already reflected through the
data.
Also we should note that once when -- and Pete, maybe you
can tell us about once when they discover failed you did certain
degradation mechanism which can result in common cause data. It's this
program proposed to go and look at other locations which are exposed to
the same conditions. So we don't expect that these failures are going
to happen instantaneously, but if one of them fails, we're going to go
and look in the similar locations and make sure it doesn't happen on
those locations.
DR. APOSTOLAKIS: I guess one question that comes to my mind
is can what Dr. Powers said go undetected for a long time? Can the
chemistry of the water be off and allowed to corrode the pipes, for
example, or there are other mechanisms for catching it?
MR. MITMAN: There is plant systems or processes to monitor
chemistry, and those processes would apply whether you're using ASME
section 11 --
DR. APOSTOLAKIS: Sure.
MR. MITMAN: Inspection criteria or these inspection
criteria. If that went undetected, then most of the damage mechanisms
would exhibit themselves as a gradual change in wall thickness or crack
growth, and we should begin to see the effects of that on the plant.
DR. APOSTOLAKIS: So it's not just a probability of
committing the error. You have to include in the calculation the
probability of catching it. And since the degradation mechanisms
operate at a relatively slow time scale --
MR. MITMAN: Right.
DR. APOSTOLAKIS: The probability of catching it, I
suspect -- I don't know -- would be pretty high.
MR. MITMAN: Most of the detection --
DR. APOSTOLAKIS: Is that correct, from the plant people?
DR. BARTON: I agree.
MR. MITMAN: Most of the detection of the events is going
from leaks that are being picked up by leak-detection systems or
pressure leak testings and walkdowns of systems. That's how we've found
leaks in the past. Typically you're not finding leaks by nondestructive
examination.
DR. POWERS: So we want them to have bad chemistry so we can
pick it up quickly by detecting leaks.
DR. SHACK: No, I mean, he monitors water chemistry in the
primary and secondary --
DR. POWERS: I grant you that they monitor it, but there is
clearly the opportunity for a failure of that monitoring process. I
mean, something goes wrong in the course of doing the monitoring, and it
seems like, I mean, one of the concerns you have, maybe not in
connection with this particular issue, but in general, is if we hide
that failure of -- control the water chemistry within the pipe damage
frequency, you know, just lump it all together and hide it in there,
then when we come through and we use this PRA to say what are the
risk-important systems in this, the monitoring of water chemistry is
effectively hidden from us, and we attribute everything to the integrity
of the pipes, when in fact what we ought to do is make sure our
water-monitoring chemistry is good.
DR. BARTON: There's a QA program. I don't know where
you're coming from, Dana. You take samples, you analyze them, there's a
QA program on the chemistry lab, the techs are qualified, examined, et
cetera, et cetera. So there's ways to catch problems in the monitoring
system.
DR. POWERS: All that gets you down to is a 5 times 10 to
the minus 3 probability of human error. I mean, that's the best you can
hope for for all those systems.
MR. DINSMORE: This is Stephen Dinsmore from the staff.
We discussed the CCF problem that you could have a
degradation mechanism acting on several different segments at the same
time, but essentially what we decided was yes, that might be true, but
you're probably going to get a failure somewhere first. The whole
system isn't just going to disintegrate on you. And when you get the
first failure, a leakage or even a rupture, then that's a fairly large
event, I mean, people are going to pay attention to that. It's not
going to disappear in the plant records. So to get a second failure or
the third failure within the time frame which would -- so they'd be
acting together we didn't think was a real credible process. And that's
kind of why we --
DR. POWERS: Well, I would assume that it's driven by your
pressure transient frequency. I mean, in normal operation I think
you're right, you're going to fail someplace first, unless you have a
pressurization wave going through the system, and then you can get
multiple failures. I mean, water hammer of course is the classic
example of that, where you can get multiple failures from a single
event.
MR. DINSMORE: Due to the slow degradation and then the
extra kick from the water hammer.
DR. POWERS: Yes, you can put the extra punch into it, and
then it's enough to -- you just can't relieve fast enough through a
single break. So it breaks everything.
MR. DINSMORE: Supposedly when they do the consequence,
they -- or I mean the degradation, they look at whether they can get a
water hammer. And if they can, then that should bump -- that's supposed
to bump the categorization for the degradation to the next highest
category, which I'm not sure entirely addresses your question, but it
is --
DR. POWERS: That's the mechanics of carrying it on. What
I'm worried about is how we use PRA to hide plant systems here.
DR. SHACK: But, I mean, these processes are slow. I mean,
even if you colossally screwed up the water chemistry, I mean, the
stress corrosion crack is still growing a quarter inch a year. I mean,
it isn't as though it --
DR. POWERS: I understand.
DR. SHACK: Is going to rip through the pipe.
DR. POWERS: I understand. And your detection frequency is
zip till it gets about halfway through.
DR. SHACK: Well, no, but your -- I mean, the chances of
having your water chemistry screwed up for a year, you know --
DR. POWERS: I would think are pretty --
DR. SHACK: Are about 5 times 10 to the minus 3, you know.
DR. POWERS: I think for having it screwed up for a year or
like you say 5 times 10 to the minus 3, having it for two years, then I
grant you it drops off pretty dramatically there, simply because you
have multiple people looking at these things.
DR. SHACK: Well, even now, I mean, you have multiple
people, you have online instrumentation, you have grab samples, I mean,
all of that would have to get screwed up. It's just -- it seems to
me --
DR. BARTON: Pretty incredible.
DR. SHACK: Yes, that's --
DR. POWERS: All you're talking --
DR. SHACK: I wouldn't lose too much sleep over that one.
DR. POWERS: All you're talking about is redundant systems.
We do it all the time in PRA.
DR. BARTON: Yes, but they're not redundant, online
monitoring systems are different than grab samples and then go to a chem
lab and use an entirely different set of instrumentation.
DR. POWERS: They're redundant and diverse, okay? They
still have a common cause failure probability, and it's not zero.
DR. MILLER: What is the common cause there?
DR. POWERS: Probably a miscalibration.
DR. SHACK: But it's to miscalibrate your online
instrumentation and then to miscalibrate --
DR. BARTON: And then miscalibrate the chem lab equipment so
that they're both miscalibrated the same.
DR. POWERS: Actually it's extraordinarily easy. All you
have to do is have the calibrants wrong.
DR. MILLER: You're saying the calibration could be at the
same lab then for all of them and that would be the common cause?
DR. POWERS: Just the standards being miscalibrated.
DR. MILLER: I think we're grabbing at straws here.
DR. POWERS: Well, you may think that, but I happen to have
run chemistry labs for years and seeing go on for a year doing --
DR. SHACK: Now we know what the problem was.
[Laughter.]
DR. POWERS: Okay. I mean, I've seen it. It goes on where
you got the analysis done AA and gravimetric and they got the same
numbers, they agreed exactly, and they were just flat wrong. And, I
mean, these things happen. Why it's not in the PRA is something of a
mystery to me. I mean, if you're trying to use PRA to tell you what the
risk-important systems are, why isn't this modeled? Why is it hidden in
the pipe damage frequency?
DR. APOSTOLAKIS: Another question, relevant question I
guess is if you go to the tables in the report, 2-1 and 2-2, I guess,
yes, you report 1,145 failures. Did you look to see whether in some of
these you didn't have -- maybe you didn't have an actual common cause
failure, you know, in other words, two things failed within a short
period of time, but maybe you only had one, but you had a situation like
what Mr. Dinsmore described where other segments were close to failure
but they just didn't fail. In other words, does this evidence of 1,145
failures include any of this?
MR. MITMAN: The --
DR. APOSTOLAKIS: You have two systems. Ultimately one
fails, and that's part of the 1,145. But maybe the other one, you know,
was eroded by a certain amount and could have failed two months later.
Did you search for these?
MR. MITMAN: In the data base of 1,145 events, those events
are only what we categorize as failures, which is leaks or ruptures.
However, one of the things that we're working on is an expanded data
base that also includes cracks and other non-through-wall events. That
data base is now up around 4,500 events. It's not discussed in the
literature at all. But there is work that's being done to look at the
non-through-wall events.
DR. APOSTOLAKIS: But if you want them to use that
experience, wouldn't you have to go a little deeper and look at the
mechanisms and some models of the mechanisms, you know, which would
contradict the advice from your reviewers on page 225 that the reviewers
agree that with a decision to rely on service experience rather than
probabilistic fraction mechanics?
I don't think you can use failure rates the way you derive
them if you start looking at partial erosion.
MR. MITMAN: Right.
DR. APOSTOLAKIS: Because you haven't failed.
MR. MITMAN: Right.
DR. APOSTOLAKIS: You can't use that in any other way in the
current system. Unless you have a model that goes deeper and looks at
the rate at which you remove material, for example, that evidence is
useless to you.
So you are looking now to see whether you will have to go
deeper, delve more deeply into this or is it just a first step to get
insights perhaps and then see -- then defer the decision.
MR. MITMAN: Currently we are looking at expanding the
database, adding more data in it to see what we can learn from
non-leaking events. There are no plans at this point to go out and
expand the model to try and predict crack growth rates or --
DR. APOSTOLAKIS: Rate of --
MR. MITMAN: Right --
DR. APOSTOLAKIS: But you are looking for this kind of data?
MR. MITMAN: We are looking. We continue to monitor the
events in the industry --
DR. APOSTOLAKIS: Okay, so if you find 65 events where you
had an inch or so eroded away, then you may reconsider your decision not
to revisit the models?
MR. MITMAN: Right.
DR. APOSTOLAKIS: Okay.
DR. SHACK: But in fairness if he finds physical conditions
that produce degradation, he assumes that degradation is possible
through the whole piping system where those conditions are present so it
is common cause failure to that extent that if this piping system is
susceptible to FAC it is susceptible, and then, you know, I am not sure
if the piping system busts once or it busts in three places -- you know,
a double-ended guillotine break is a double-ended guillotine break.
DR. APOSTOLAKIS: No, but right now they find that kind of
evidence, they have no place in their model to use it.
DR. SHACK: No. If the physical conditions are such that it
is susceptible -- then every segment there is susceptible to
flow-assisted corrosion.
MR. MITMAN: When we are looking at a system we look at, on
the degradation analysis side, we look at the system and we break it up
into ISO damage mechanism segments.
That is half of the decision on what defines a segment, so
we are looking at pieces of the system that have the same damage
mechanisms applicable to it.
Likewise, on the consequence analysis, we look at continuous
runs of pipe that have the same consequence, and that for us defines
what a segment is. A segment has to have common susceptibility to
damage mechanisms and common consequence evaluations, so we are looking
at effects of the damage mechanisms across segments and multiple
segments in a system or among several systems.
DR. APOSTOLAKIS: So let me get again a clear answer from
you. Do you feel that this exercise that you report here is done in the
name of defense-in-depth and it doesn't really have an impact on the
plant or not? I am not talking about the augmented flow accelerated
corrosion program and so on, just this ISI.
You say there that the program -- I mean your last bullet --
MR. MITMAN: Right.
DR. APOSTOLAKIS: -- that started this whole discussion is
that there is no impact on risk. Is it your clear statement that this
is a defense-in-depth requirement whose rationale escapes you?
MR. MITMAN: Are you asking why we are doing the
methodology --
DR. APOSTOLAKIS: No, not the methodology.
MR. MITMAN: Why we are doing inspections?
DR. APOSTOLAKIS: Yes. In light of your last bullet.
MR. MITMAN: In a perfect world I think it is safe to say
that with the current plant designs we would decrease, we would further
decrease the number of inspections. We would not walk away from all the
inspections. We would continue to sample somewhere around five percent
of the welds to continue to monitor the plants and the industry to make
sure that there are no new damage mechanisms or that the damage
mechanisms we already have identified don't change and don't accelerate,
so in that sense we would continue to do the inservice inspection.
From a probabilistic standpoint, other than making sure that
no new damage mechanisms occur, I think it is safe to say that the
probabilistic analysis does not -- drives us to the conclusion that you
really don't have to do a lot of ISI analysis.
DR. APOSTOLAKIS: One question that I didn't get to ask this
morning, this worth of the subsystems, and I can't find it now, of the
trains, who does that? Is it the PRA analyst that says it is .5 or 1 or
you have a whole table here of which -- that I had in front of me just a
minute ago. Is it Vesna that does it or Fleming or somebody who doesn't
know how to spell P-R-A?
MR. MITMAN: It would be done by a PRA expert, either a
contractor or by the plant PSA personnel.
DR. APOSTOLAKIS: So what does the engineer then who uses
this do?
MR. MITMAN: The ISI or piping engineer?
DR. APOSTOLAKIS: Yes.
MR. MITMAN: Once the tables are calibrated then he can
apply those tables to help him to determine what consequence category
the piping segments fall into.
DR. APOSTOLAKIS: I see -- so when he looks at this, and the
table tells him that RCSI is .5 worth, he does not question that.
MR. MITMAN: At that point, no. The question should have
been asked earlier.
DR. APOSTOLAKIS: Well, I'll repeat what I said this
morning. I mean it is a mystery to me why we have to do all this when
there are simpler ways of doing it, but I guess -- et cetera.
DR. SHACK: If there are no more questions, perhaps we can
move on to the Staff.
MR. MITMAN: Thank you.
MR. DINSMORE: Yes, this is Steve Dinsmore from the Staff.
Are you waiting for us?
DR. SHACK: Yes.
MR. ALI: My name is Syed Ali, I am from Division of
Engineering, NRR, and with me is Steve Dinsmore from DSSA and NRR. What
we are going to do is very briefly give you an update on some of the
changes, improvements that EPRI has made since we approved some of their
pilot plants. This morning and also in EPRI's discussion afternoon,
they already went over the status of the various stages of the submittal
of the EPRI topical report, our issuance of questions and comments, and
their responses.
In addition, we have approved at this time -- at this point
we have approved two pilot plant ISI submittals. One was Vermont Yankee
and the other was ANO 2. Since the approval of the pilot plants, EPRI
has submitted the final topical report and there are a few items that we
have highlighted here that are changes or improvements to the items that
were included in the pilot plants.
Specifically, in the pilots and in the original version of
the EPRI topical report, the discussion or the treatment of the
augmented ISI plans was not clear. And just for clarification, this
question came up this morning also. By augmented inspection programs,
we mean inspection programs that are over and above or in addition to
the ASME Section 11 inspection programs.
In the current version of the EPRI topical report, they have
clarified the extent to which the various augmented inspection programs
will be addressed. As an example, the IGSCC category A weld, which is
the welds for the materials that have been replaced or improved, those
type of welds will be subsumed or included in the risk-informed ISI
program. Other than that, all other IGSCC category B through G welds
will be done -- will be treated the same way that they are being done
currently in response to the NRC Generic Letters and the licensee's
commitment to the NRC.
Similarly, the erosion/corrosion or the FAC program that the
individual licensee has committed to is going to be unchanged at this
time and not included in the risk-informed ISI program.
The second item which is the proposed submittal of
templates, a little bit of background on that is that the staff issued
its Regulatory Guide and Standard Review Plan late last year. Around
the same time we also approved the Westinghouse topical report and three
of the pilots, one based on the Westinghouse methodology and two based
on the EPRI methodology.
Subsequent to that, staff and industry had several
discussions and decided mutually that it will be beneficial if the staff
and industry can agree on a submittal which is a simplified submittal as
long as the submittal states clearly that it is in compliance with
either the Westinghouse methodology or the EPRI methodology and,
basically, give exceptions to those methodologies, if any. So,
therefore, we agreed on a template or a simplified submittal that should
expedite the staff review. So the revised EPRI topical report includes
that proposed template.
The third item on this slide is that --
DR. APOSTOLAKIS: So this is simplified now to the extent
that one does not even have to have heard the word PRA to use it? We
have completely eliminated PRA from this?
MR. ALI: Well, it is --
DR. APOSTOLAKIS: You don't have to respond.
MR. ALI: No.
DR. APOSTOLAKIS: It was just a comment.
MR. ALI: It is just so that if the individual plant is in
full compliance with the particular methodology, then they don't have to
give the details of the results. But they are available if the staff,
you know, chooses to audit in a particular case.
MR. DINSMORE: This is Steve Dinsmore. I would like to
respond a little bit. Part of the methodology is that you use your PRA
to confirm that your trains are given the appropriate weights and to
confirm several different things with your PRA, so we would assume that
they would have done that. They don't have to come in and say we did
this, this, and this. They would just say we followed the methodology.
Part of the template is also to give us a little information
about the PRA. Also to respond to all the comments which the staff has
made about the PRA to date to ensure that they have either addressed
them or why they don't think that these have an impact on the results of
this.
And there are a couple of tables in there which will allow
us to see if there are some strange things. For example, if they have
CCDP for a large LOCA of 10 to the minus 5, we might question why they
got it that low.
So there is enough in there to kind of give you an overview
of what they used and how they used it. And if we see something that we
feel should be pursued, then we would pursue it. But that is
essentially the way we were going with this template.
MR. ALI: The next item is that the pilots that we have
reviewed and approved so far either were based on a full plant
application of ISIR on a class 1 -- entire class 1 part of the ASME.
However, in the EPRI topical report they have also now provided the
choice of applying the risk-informed ISI methodology on a system by
system basis. They have provided a slightly more strict criteria as far
as risk in order to provide some margin. Actually, it is about an order
of magnitude lower change in risk that is permitted. So that is
something that is different than what we have approved or looked at so
far, and the staff is currently reviewing that.
Some of the changes in the risk calculations, Steve will go
through that.
MR. DINSMORE: Thanks.
This is Steve Dinsmore from the staff.
There's a couple of minor differences between what they
submitted in the pilots and what is given in the topical. The first one
there is there is some slight changes in what the classification is for
individual elements within those tables. That has to do with comparing
to the criteria, and we're working on that.
This is just to give you an idea that there are some changes
and what they are, and if anything bothers you, then you can ask.
There's a number of changes in the delta risk calculation
criteria. The first one is that they're requesting not to do a delta
risk calculation for class 1 only because they say they're doing 10
percent and that the normal service experience indicates that you can go
from 25 to 10 percent without increasing risk and in fact decreasing
risk if you select your welds with degradation mechanisms to examine.
We're still pondering that one, mainly because we didn't see
a description of how you can compare your particular plant to the
generic service experience to make sure that that connection is made.
They don't want to include delta risk contribution for low safety
significant segments. There's a fairly good argument in the topical as
to why they use bounding analysis to show that that probably won't
impact the results, so we're kind of leaning towards that.
They added these specific screening criterias on the delta
CDF and the delta LERF. The first line is system level screening. If
you did a full scope, you don't want to get a plus delta CDF of 10 to
the minus 7 or a LERF of 10 to the minus 8. The second one was what
Syed briefly mentioned, which was if you only do one system, you don't
want to get a delta CDF of greater than 10 to the minus 8 or LERF 10 to
the minus 9.
In general, with the risk-informed stuff, we initially said
you that you have to do full scope, but we've been kind of moving back.
With the single system, we might think that you might come in with a
negative. That would help a lot. If you came in with a positive on a
single system, you might come in 10 times with 10 different systems and
a slight positive. So there's a little bit of confusion as to how
that's going to work out in the end.
The last one is the added Markov option to the original --
originally, they just said this qualitated in a bounding option. They
used the bounding options for almost all the pilots. They used one
qualitative argument for LERF, I think VI did, and the other three were
these bounding calculations.
They added Markov. We've just kind of gathered all the
paper to review Markov. It looks reasonable to us. We've got some --
DR. APOSTOLAKIS: So you haven't approved it yet?
MR. DINSMORE: We haven't approved it yet.
DR. APOSTOLAKIS: Are we going to see it?
MR. DINSMORE: The paper upon which we're going to base our
approval or rejection or comments, you certainly can see, and you'll see
the approval or rejection, whatever, whenever we do that. If you would
like the background paper --
DR. APOSTOLAKIS: Are we going to write another letter in
the future about this?
DR. SHACK: Well, we haven't even seen the draft SER yet,
which --
MR. BARTON: We're not writing a letter this time, but we
will have to write one at some point.
DR. SHACK: I mean, that's something we can discuss. But
the thought this morning was we wouldn't write a letter because they're
still coming up with a draft SER in June.
DR. APOSTOLAKIS: And the SER will include your decisions
and the major changes?
MR. DINSMORE: Correct.
DR. SHACK: Or open questions if there's open questions.
DR. APOSTOLAKIS: So at that time, we may ask questions.
And is EPRI coming back then, or that will depend on what we want to do
at the time? Okay.
MR. MITMAN: This is Jeff Mitman from EPRI.
We'll come back as necessary. We're planning to come back
in either July or early September.
DR. APOSTOLAKIS: Why -- I mean, maybe there's something I'm
missing here -- why do we have an augmented FAC program and then
risk-informed ISI?
DR. SHACK: In a way, augmented was, you know, the first --
when you realize the ASME code wasn't looking in the right places --
DR. APOSTOLAKIS: Right.
DR. SHACK: -- the initial reaction was to tell them to go
look in the right places. That was the augmented program. You know,
that's one of the reasons the ASME doesn't find things, is it's the
augmented program that's looking --
DR. APOSTOLAKIS: Right.
DR. SHACK: -- where the action is.
DR. APOSTOLAKIS: But we will have the augmented and this?
That's what I was given to understand this morning.
MR. DINSMORE: Right.
DR. APOSTOLAKIS: And why is that? I mean, this seems to
address FAC and other things as well.
MR. DINSMORE: One of the things this allows you to do,
which is in the new topical, is you can use your augmented inspections
as Section 11 inspections. So if you're doing 10 percent augmented
inspections on your primary, you probably end up -- if you've selected
those right, you might change some of those because now you're
considering risk consequences, which I'm not sure they did when they did
the augmented.
DR. APOSTOLAKIS: So they will be combined? Is that what
you're saying?
MR. ALI: Well, what they're not doing at this time is since
we feel that the augmented programs are appropriate and should continue,
so -- at least these two programs, the FAC and the IGSCC B through G,
they're not going to reduce those inspections, they will continue what
the industry and the staff has agreed to do, at least at this time.
DR. APOSTOLAKIS: So what's the purpose of this, then? I
mean, what's the logic behind not combining them, and say, you know, we
did this because we realize that Section 11 was not perfect, but now
that we have this new RI ISI, we don't need that augmentation.
MR. ALI: There are certain programs that are taking place.
For example, for IGSCC, there is a dialogue between the BWR Owners'
Group and the NRC which was going on on a parallel path because of the
experiences that have been learned on that to revise that program or
possibly revise that program.
The main thrust of these -- of the Westinghouse as well as
the EPRI program has been that the ASME inspections are a little bit too
much, maybe not beneficial to the extent that the inspections are done,
that those inspections can be done in areas which are more prone to
finding defects and to a lesser extent. So the main emphasis has been
to actually revise or change the ASME criteria, at least as a first
step.
I mean, you know, also keep in mind that right now, this
program is only being applied to piping and nothing else, so, I mean,
whether that will be done in the future or not also is something that
the industry will probably be looking at. Actually, they are looking at
that. So we consider this is a first step, this is how it has started
out.
DR. SHACK: It's the path of least resistance.
DR. APOSTOLAKIS: Would you explain that in --
DR. SHACK: Well, it's --
DR. APOSTOLAKIS: -- common English?
DR. SHACK: Rather than having --
MR. BARTON: Explain it in PRA terms.
DR. SHACK: Rather than having to go past the augmented
inspection, you know, you just ask for what seems relatively easy to get
at the moment. They'll be back trying to put it all together. The
frame work clearly --
DR. APOSTOLAKIS: So eventually, they will put everything
together?
DR. SHACK: Yes. I'm sure they will in the -- you know,
well, as much as one can foretell the future, yes.
DR. APOSTOLAKIS: Are there any plans for that?
MR. ALI: Yes. Like I said, the -- we know that for IGSCC,
there are discussions on what is the best way to devise the program,
whether it should be based on risk or deterministic experience. But
that's something that's going on.
MR. DINSMORE: You see, Dr. Kress mentioned this morning
that the augmented programs are already for costs. The ISI ones were
not for cost. So the augmented programs are already looking for
degradation mechanisms, so it's not as clearly a better idea to change
them kind of quickly and easily like we're doing this with the ISI, the
ASME Section 11. So they can do the Section right now and it saves them
a lot of man rem exposure and all this stuff, and so it is, as you said,
it's least resistance.
MR. ALI: But it moves quickly.
Pete?
MR. RICCARDELLA: Yes. This is Pete Riccardella from
structural integrity.
I think, you know, the overall approach of this
risk-informed ISI approach is to look at the places where there are
degradation mechanisms that are applicable, and we considered 10 or 15
different degradation mechanisms -- IGSCC, FAC, thermal fatigue. You've
seen the list of them. And as we went through this, we concluded that,
well, the IGSCC and the FAC are already being covered adequately and
there's and need to reinvent that wheel, but all of these others aren't
being considered.
So as we go through the process, we do consider locations as
to whether they're susceptible to FAC or whether they're susceptible to
IGSCC, and if we conclude that, we say, well, they'll continue to be
inspected in accordance with the current augmented programs. But it's
all the other things that we pick up, thermal fatigue and the others,
that we're addressing in this process.
DR. APOSTOLAKIS: But the existing programs are not
risk-informed, are they?
MR. RICCARDELLA: Well, they --
DR. APOSTOLAKIS: The existing IG --
MR. RICCARDELLA: In general, they didn't consider
consequence, but they did -- they're risk-informed from the standpoint
-- they're doing the same thing that we're doing on the degradation
mechanism side -- that's determining whether the degradation mechanism
is applicable. In general, they didn't consider the consequence side.
But the IGSCC -- it's all class 1s, so it's all fairly high
consequence anyway, and the FAC -- well, as we go through it, if there's
FAC in the systems that we're applying it to, we take a consequence look
at it as well.
DR. SHACK: Again, Tom, George and Dana weren't here this
morning. I guess the rest of us had more or less tentatively come to
the conclusion that we probably didn't need to write a letter this time
unless people had some major objections or major points that they felt
we needed to make, and I guess perhaps that's something we can either
discuss later or if somebody sees a reason that we need a letter now, --
DR. APOSTOLAKIS: When will we get the staff's --
DR. SHACK: The SER, draft SER?
MR. ALI: We currently plan to have a draft SER which might
have -- may or may not have some open items sometime in June.
DR. APOSTOLAKIS: So then we will write a letter in
September sometime, or July?
DR. SHACK: Well, we probably would write it, I would think,
at the final SER, unless, again, we had problems.
DR. APOSTOLAKIS: Okay.
MR. ALI: We expect that we'll come back again once we have
the SER to present that, then, you know, that will be the time that we
will be asking for a letter.
MR. MARKLEY: The other thing you'll have is the benefit of
the changes that EPRI might make in response to that draft SER. So you
will have the full package at that meeting.
MR. ALI: We don't have anything else, unless you have some
questions.
DR. SHACK: I'll turn it back it you, Mr. Chairman.
DR. POWERS: So what I derive from this is that we'll leave
open the option to write on the final SER, but it's not assured.
DR. SHACK: Oh, I think we would write on the final SER.
DR. POWERS: Oh, okay. So we will write on the final SER
barring complete collapse of the committee to do anything.
DR. SHACK: Right.
DR. POWERS: Thank you. Okay. Which is imminent.
Well, thank you, gentlemen.
MR. ALI: Thank you.
DR. POWERS: We turn now to one of our favorite topics,
which is the proposed final revision to 10 CFR 50.59, and Mr. Barton, I
believe you've grown old with this subject.
MR. BARTON: Old and ready to retire.
This was originally scheduled for 1:45 to 2:45. Mr.
Chairman, would you like me -- we'll try to get finished with this as
soon as we can, but we probably will not make 2:45.
DR. POWERS: No, I think this deserves our close attention
and with the apologies to Dr. Fontana and the Calvert Cliffs, I may eat
into that time. This is one of our high priority activities, and I know
that Eileen McKenna would resent considerably the full time --
opportunity to present in front of this committee.
[Laughter.]
MR. BARTON: Thank you.
The purpose of the meeting this afternoon is to review the
proposed final revision to 50.59. ACRS last reviewed the proposed
changes in March. The committee issued a report at that time to the
Chairman. The staff's commission paper on the proposed final revision
to 50.59 supplements the recommendations made in SECY 99054,
incorporation of results of meetings with the NEI which appear to have
been beneficial in resolving the differences between the staff and
industry as well as informal feedback from the Commission.
Major changes in the proposed rule since we last reviewed
this with the staff are the addition of two new criteria, which I'm sure
Eileen will cover in detail.
In additional to the staff briefing, we'll hear from NEI
this afternoon, comments regarding the proposed final rule. The
committee report will be developed, prepared and sent to the Commission
as a result of this meeting.
At this time, I'll turn it over to the staff, Mr. Dave
Matthews, to introduce the speakers.
Dave.
MR. MATTHEWS: Well, you've done an excellent job already of
doing that. I think you're all familiar with Eileen, who has been our
senior project manager with regard to revision to Part 50.59 and now
associated proposed revisions to other portions of the regulations who
rely upon similar language and similar change control processes, Part 72
being one in particular, and there's also a Part 71 implication.
This rule does address where we are on Part 50.59. It does
address changes to Part 72, and it addresses potential changes in the
future to Part 71.
The focus, though, I think is rightly on Part 50.59 as
applies to operating power reactors, and we want to also focus as well
on criterion 7 and 8 as they're referred to in our presentation this
morning.
I would indicate that the staff is still in the throes of
deliberation with regard to a final recommendation to the Commission on
implementation schedules, and the attendant enforcement policy that may
ensue during that implementation period. So we have provided you a
draft package. The substance of the changes to the criteria is not
going to change, I can tell you that, with regard to that package;
however, those portions that address implementation period and
enforcement policy may change before it reaches the Commission at the
beginning of next week.
So just with that slight clarification, I'll turn it over to
Eileen.
DR. POWERS: Before we plunge into the details, I know that
part of your motivation to make changes in Part 71 came from public
comments. Have you had any additional feedback on proposing to change
Part 71?
MR. MATTHEWS: Beyond those public comments, no, but we've
had some additional thoughts on a schedule for doing it in our
discussions with NMSS. So I think Eileen is prepared to address that as
well.
MS. McKENNA: Okay. Thank you.
The first part, I won't belabor because I think we've had
plenty of discussion in the past. As is indicated up here and was
mentioned in some of the introductions, we had the earlier paper, which
this paper is supplementing; we had a Commission meeting; and while we
did not get an SRM or specific votes on that, we did have some good
discussion with the Commission at that meeting and the SRM and the
briefing and established the date of may 10th, which is obviously coming
up very quickly, for sending the package to the Commission.
We've had interactions with the --
DR. POWERS: Quick question, Eileen.
MS. McKENNA: Yes.
DR. POWERS: Is it took quick for you? Is it not quick
enough?
MS. McKENNA: Well, I think it's more the latter at this
point.
[Laughter.]
MS. McKENNA: As mentioned, we had a number of briefings
with the ACRS, most recently in March, and I think we are -- the
committee expressed their support for moving forward the rulemaking with
expression that we hope we could close on these last issues with margin,
which I think we have been able to do.
As I say, what we've forwarded to you was the final
rulemaking package a week or so ago. It's had very minor changes. I
think David kind of illustrated the areas that we're still wrestling
with as to exactly what to propose as how long to give for
implementation.
There are some trade-offs between -- since we do feel that
on an overall basis, it provides more flexibility and clarification is a
reason to move faster, but when you're doing rule but when you're doing
rule changes and people are -- want to make sure they have time to
familiarize themselves with everything that's been changed, and have all
the people brought up to speed so that, you know, that is a bit of a
trade-off as to exactly how long you should allow for that process.
And we are trying to come to a final recommendation on that.
DR. WALLIS: Can I ask you about the final bullet? I
received a package, and it seemed to have still discussing the virtues
of various changes. It wasn't clear to me that I could find in one
place what you were proposing as the actual final rule.
MS. McKENNA: The language is in -- is kind of at the back
several pages of the package.
DR. WALLIS: It wasn't -- I couldn't find -- this is the
final thing that you would like approval of. I found too much still
ongoing discussion of parts of it, but maybe I was just too foolish to
find --
MS. McKENNA: Well, the actual rule language is at the back,
and so it certainly is a long package, I recognize, and you have to
press forward I think through the sections to get to -- this is language
we actually proposed to put into the book.
DR. WALLIS: Right.
MR. MATTHEWS: The Federal Register notice itself contains
that lengthy discussion in the SOC which had as one of its purposes to
explain the evolution of our position by virtue of the fact it's
responding to public comment on the proposed rule, so it does discuss
that there were alternatives considered by the staff and the pros and
cons. But the actual language of the final position being recommended
to the Commission is included in regulatory language at the conclusion
of the Federal Register notice. So you have the words that the staff
has recommended.
DR. WALLIS: You mean they are somewhere, whether I have
them or not. Well, we can sort that out.
MR. MATTHEWS: I am confident that they are in that package.
Whether they're sufficiently labeled as this is it, I can't make a
claim. But I'm confident they're in that package.
DR. APOSTOLAKIS: The package we have here.
DR. BARTON: It starts on page 116.
MS. McKENNA: Right. The way that these things typically
are done, you have kind of the background and discussion of what led up
to it, and then kind of here it is, jump to page 116.
DR. WALLIS: Can we have before we write a letter, please,
since I don't have that, a definitive package which is the final rule as
we are asked to sign off on it or whatever we have to do?
MR. MATTHEWS: I just reassured you you have that.
DR. WALLIS: I don't, because it's not here.
MR. MATTHEWS: Sorry, I can't make up for that problem.
DR. APOSTOLAKIS: 115?
DR. SHACK: 4-26-99 is the latest I have.
MR. MATTHEWS: Your colleagues have that.
DR. WALLIS: You have? I think this is a serious thing. If
you're asked to actually sign, we should have at this meeting, whether
we brought it or not, a clear definition of what it is we're asked to
approve.
DR. POWERS: I think we can get that for you if we need to,
and in deference to the speaker, I think that it's also worth mentioning
that we have put this on a little faster track than might normally be
done, and it's proved to be a minor bit more contentious than most.
Only modestly.
MS. McKENNA: Just modestly, though.
DR. POWERS: So maybe if we can make sure that Graham has
the exact language in front of him.
Yes, it's coming.
MS. McKENNA: Okay. Just to pick up on the last bullet,
which was referring to the final package, there is a forwarding paper,
it will be a SECY paper, that discusses those areas where there may have
been either some evolution or change in the position, and primarily it's
on the criteria 7 and 8, which I will elaborate on shortly.
There is some -- you probably saw a section in there where
we talked about some of these other regulations and how they fit
together, in particular parts 52 and 54 and 71, which we're not actually
changing through this rulemaking, but we are noting some of the
connections and how they fit together, and then mention -- there will be
a section, exactly what it says, I think in the version we talked about
in 18 months or somewhat earlier, we're now perhaps thinking of giving a
flat 12 months' time frame, but the Committee suggests that perhaps we
could do it sooner than the 18 months, and we've been looking at that.
I think the thinking is that 12 months is kind of the right
time frame to allow for the guidance to be revised, for people to become
familiar with what's going on and to actually implement the changes.
DR. POWERS: Excuse me, just a little bit, between the time
of now --
MS. McKENNA: Right.
DR. POWERS: And whenever the clock stops on this 6, 12, or
18-month time period, this is not a large uncertainty with respect to
50.59 --
MS. McKENNA: No.
DR. POWERS: What are people using?
MS. McKENNA: They're using the existing rule and the
existing processing.
DR. POWERS: Which is more restrictive --
MS. McKENNA: Correct. And that's safe.
DR. POWERS: Why aren't you willing to let them take
whatever time they want?
MS. McKENNA: Well, that's one of the considerations is they
could take -- we're wrestling with whether to set a longer period of
time and say if you want to follow the old rule, that's fine, because it
is more restrictive, and --
DR. BARTON: And it's worked for 30 years.
MS. McKENNA: And it's worked for 30 years.
DR. POWERS: It seems to me that -- why do you care?
DR. APOSTOLAKIS: The way I understood it was that it was
more restrictive on paper, not the way that it was implemented.
MS. McKENNA: Well, I think --
DR. APOSTOLAKIS: The idea of a minimum increase was
actually implemented de facto.
MS. McKENNA: You're right in terms of the way people
implement and the way the words are written may not have matched
completely. I think the thinking is that with the revised rule, there
will be a better match between how people generally do these things and
what the rule says, and for that reason, it may be better to have it
sooner, so you wouldn't have this, you know, perhaps this disconnect
between what people do and what the rule says.
MR. MATTHEWS: There is one additional advantage to reaching
to implementation under the new rule sooner rather than later, and
that's driven by the corrective action for a violation of the existing
rule is to submit an amendment to get NRC approval of the change that
you have made to the plant, and if you were to have a rule that was more
restrictive rather than less restrictive, you get more of those
amendments that under the new rule you wouldn't have to process. So
there's some motivation on the part of the staff that we don't think
it's --
DR. BARTON: You get an enormous number of those?
MR. MATTHEWS: We think there's an unnecessary regulatory
burden to submitting amendments that when the new rule is implemented
wouldn't have to be reviewed.
MS. McKENNA: It's not an enormous number. It's, you know,
10 over -- it's hard to estimate, because --
DR. POWERS: It's absolutely nothing compared to the effort
that you've gone to --
MS. McKENNA: That's true.
DR. POWERS: Develop this.
MS. McKENNA: That's correct. Yes.
DR. POWERS: Why do you care? I mean, if they want 18
months, fine, give them the 18 months. I mean, what difference does it
make.
MS. McKENNA: Okay.
DR. APOSTOLAKIS: Done with that viewgraph?
MS. McKENNA: Yes, unless you had a question.
DR. APOSTOLAKIS: I have one.
MS. McKENNA: Okay.
DR. APOSTOLAKIS: Okay. I understand the actual rule starts
on page 115.
MS. McKENNA: Yes.
DR. APOSTOLAKIS: Now the first 115 pages will become a
public document.
MS. McKENNA: The whole thing is published in the Federal
Register.
DR. APOSTOLAKIS: Okay. So we have to be careful what we
say.
MS. McKENNA: Yes.
DR. APOSTOLAKIS: Okay. On page 35 --
MS. McKENNA: Okay.
DR. APOSTOLAKIS: I would beg you to delete the sentence at
the end of the top paragraph: For the final rule the Commission has
also substituted the term likelihood for probability for clarity.
They're identical. They mean the same thing. We don't want
to embarrass our industry by putting statements like that down. Even
though it may have been done for that purpose, I would delete it.
Page 35.
MS. McKENNA: Page 35, the top.
DR. APOSTOLAKIS: Page 35.
DR. WALLIS: Unintelligible.
DR. APOSTOLAKIS: It's unintelligible? No, it's typed.
[Laughter.]
It says Nuclear Regulatory Commission -- are you on page 35?
MS. McKENNA: No, I think he's looking at the rule language.
DR. WALLIS: I'm on page 3.
DR. APOSTOLAKIS: Well, you can make your comments
afterwards, but what I'm proposing is that on page 35 that sentence be
deleted.
MS. McKENNA: Okay. We'd need to say that we're making the
change. If your concern is that you don't like the basis of clarity, we
can look at that and see if we can say something different.
DR. APOSTOLAKIS: I don't even know that you make the
change --
MS. McKENNA: Yes, the change is made.
DR. BARTON: On page 34, the change has already been made,
George.
DR. APOSTOLAKIS: Right. I understand that. But that
sentence by itself really leads to the wrong conclusions and
impressions, and I really don't want that. I'm not saying don't change
it.
DR. BARTON: What bothers you, the "for clarity"? How about
they put a period after "probability"?
MS. McKENNA: Yes, that I can do, is put a period after --
DR. BARTON: The Commission has also substituted the term
"likelihood" for "probability," period.
MS. McKENNA: Right.
DR. APOSTOLAKIS: It's much better --
MS. McKENNA: I think that we have to state that we have
made -- the change is being made, and if you don't like the basis,
that's something we can deal with.
DR. WALLIS: What is the purpose of that change?
MS. McKENNA: I think the purpose was to try to get to,
since we are looking at things in a qualitative sense, the "probability"
perhaps has a suggestion of numerics that "likelihood" did not, and
that's --
DR. BONACA: That you use a PRA.
DR. WALLIS: Yes, but that's the ultimate in quibbling. I
agree with George, it's simply an attempt to avoid a word which might be
embarrassing.
DR. BONACA: Yes, and, you know, I want to say that in fact
you still have not solved the issue of backfitting. If you go to page
36, top of the page, the same issue there, look what it says: Changes
that would invalidate requirements for redundancy, adversity separation,
which is defense in depth, would be considered as more than a minimal
increase in likelihood of malfunction. Which means you are dictating
that.
Now an analyst may go in, demonstrate to you that actually
the probability is decreased or is maintained the same. But here you're
de facto ruling that there's going to be an increase, and that's always
a problem, because what you're having, you're having a technical
evaluation concluding something, but you cannot conclude that, because
you have already prescribed that it is an increase.
And I can only say that by my experience it has created more
pain, okay, that issue, because you're asking your engineer to tell you
an answer to a probability increase, okay? Now, you want to call it
likelihood. The fact is, it's still a probability. So he's coming up
with a result. The result may be no increase. But by definition it has
to be an increase. And that still, that issue of backfitting there is a
problem.
MS. McKENNA: Let me see if I understand your question,
saying that you think it's possible that it could make a change that
would perhaps remove the redundancy and because of other reasons
conclude that there has been no change in the probability or likelihood
of failure.
DR. BONACA: Maybe it would help me if Professor Apostolakis
suggested in fact that where you have commitments you just create simply
a verification that a commitment is maintained, okay, and you take away
the reference from the probability, because what this is creating is
creating a conflict between verification of existing commitments and a
true engineering analysis that you expect in a safety evaluation that
will conclude something, and you're saying it doesn't matter what you
conclude in the technical evaluation for those cases where you have a
commitment to this defense-in-depth criteria you call it an increase.
See, that doesn't go well with engineers. You can't control the process
inside a company.
MS. McKENNA: Okay. I guess what we were indicating is that
you felt that these principles of defense in depth were such that if you
had them in your facility and now you're removing them that that would
be more than a minimal change in those parameters.
DR. BONACA: And I'm not saying removing, you may modify
them, okay, and the fact is that when you modify them, for example, say
that you have the separation and you change the distance between things,
okay, why does it have to be necessarily an increase in probability? In
some cases it's not because standards already exist for, you know,
reducing it.
So you see what I am trying say, there is still a difficulty
there in that you are using a technical language. You are now changing
the word to "likelihood," but it is still probability.
DR. APOSTOLAKIS: Yes, it is.
DR. BONACA: And you have a conflict between the conclusion
of a technical evaluation and what you want to backfit, which is you
have to go back because you made some change there in diversity, or
separation, or redundancy. So I don't know how we can -- you know, but,
again, there was a suggestion here, Professor Apostolakis, that we would
for those cases simply say -- not these words, but say, in case there
are specific commitments to redundancy, diversity and separation, okay,
then NRC review is required. But not because there is an increase in
probability.
DR. APOSTOLAKIS: Yeah, but that might, that recommendation
--
DR. BONACA: I know, but -- well, but the point is that this
backfitting issue is still here.
DR. WALLIS: Now, we must go. I am very sorry, we must
pursue this further because the rule is an important document, right.
Page 126, it says, "Result in more than a minimal increase in the
frequency of likelihood of a malfunction." Not only have you changed
probability to frequency or likelihood, you have changed it to both
frequency of likelihood.
DR. APOSTOLAKIS: Which page are you on?
DR. WALLIS: 126.
DR. APOSTOLAKIS: 126.
DR. WALLIS: Now, what is frequency of likelihood?
MS. McKENNA: Okay. I was going to say that is --
DR. WALLIS: It is like frequency of probability.
MS. McKENNA: That is an administrative error and I thank
you for catching it.
DR. WALLIS: But it just shows the kind of --
DR. APOSTOLAKIS: So which one did you delete?
MS. McKENNA: Frequency.
DR. APOSTOLAKIS: Frequency of?
MS. McKENNA: Yes. In item 2.
DR. WALLIS: Oh.
MS. McKENNA: It is frequency for accidents and likelihoods
for malfunctions.
DR. APOSTOLAKIS: We are raising too many --
MS. McKENNA: Yes.
DR. APOSTOLAKIS: Let's come back to page 35.
MS. McKENNA: Okay.
SPEAKER: Let's stick with one item here.
DR. APOSTOLAKIS: Would you please delete then for clarity
--
DR. WALLIS: It is all the same --
DR. APOSTOLAKIS: Do you agree to do that?
MS. McKENNA: Yes, I agree to do that?
DR. APOSTOLAKIS: Okay. Because the other stuff you have to
leave there, so it will be a mystery to some people why you substituted
the term "likely" for "probability," but at least let them speculate.
Okay. Now, on page 29, you yourself seem to alternate
between likelihood, probability and frequency. Now, this is not
official, I guess.
MS. McKENNA: Well, this was kind of the discussion of how
we got to minimal, and since probability was the way things were being
looked at, certainly as the rule is presently written and in the way
plants were licensed, we were using that terminology.
DR. APOSTOLAKIS: Listen to what you are saying here, 29.
"System train failures were generally postulated to gauge the robustness
of the design without estimating their likelihood of occurrence. In
this light, minimal increases in probability would not significantly
change the licensing basis. Further, modest increases in frequency of
the postulated" -- so we are going back and forth. And that is why I
asked you, are you going to publish this document?
MS. McKENNA: Yes.
DR. APOSTOLAKIS: You will. So maybe a good editing job
would take care of this things. Because I mean in probability theory,
likelihood and probability are identical concepts. They are the same
thing. Now, if engineers feel more comfortable with likelihood or I
understand something different, let's not advertise that.
But when we say that we have substituted the term
"likelihood" for "probability," at least let's do it ourselves.
DR. WALLIS: No, well, I object on principle. I mean you
have two words which mean the same thing, and you want to use one
because you are afraid of the other one, and this really is the wrong
way to go about regulation, which should be clear.
DR. POWERS: Well, in deference to George, I happen to agree
with him that likelihood and probability in theory are identical
concepts. But in the colloquial or the vulgar, they are not. And the
truth of the matter is that when somebody asks me what the likelihood of
something is, I give them a qualitative answer. When somebody asks me
the probability of something, I give them a deliberately quantitative
answer. And it seems to me that there is a distinction in the vulgar,
and maybe you are drawing upon that distinction here. And if so, it
seems fine to me.
DR. SEALE: This is going to be a vulgar regulation, is that
what you are telling me?
DR. POWERS: Well, when I say vulgar, I mean in the sense --
MS. McKENNA: In common terms, yes.
DR. POWERS: -- of the common.
DR. SEALE: I know what you mean.
DR. POWERS: Common usage.
MS. McKENNA: Yes.
DR. SHACK: Possibly not elegant.
DR. SEALE: Right.
DR. POWERS: We have a variety of words in the mathematic
field that have very, very specific meanings that equally -- those same
words get used in the common parlance and don't carry that baggage with
them.
DR. APOSTOLAKIS: Best estimate codes perhaps.
DR. POWERS: That might be a good -- though maybe there it
is the opposite, that in the common parlance, we think best estimate
means something significant, whereas, in the technical field it seems to
mean anything at all.
MS. McKENNA: I think you are exactly right in terms of the
thinking that we were going into, because we were reacting to comments
and concerns about -- there was a suggestion that by moving into
minimal, we were looking for numerics and we are saying, well, trying to
make it --
DR. APOSTOLAKIS: So let's do it but not advertise it.
MS. McKENNA: That's right.
DR. WALLIS: I still object. I mean if I grade someone's
work as incorrect or wrong, it doesn't make any difference, they are
same word. And if I use one because it is slightly more polite than the
other, it doesn't change the substance. So you have not changed the
substance by one jot or tittle by changing this word "probability" to
"likelihood."
DR. SHACK: Well, then why worry about it?
MS. McKENNA: We are really not trying to change how people
go about doing their business with respect to that.
DR. WALLIS: So why do it?
MR. BARTON: I think there was a suggestion that came out in
this committee to change that word.
DR. WALLIS: No, but we claimed to have fixed a problem by
changing a word which makes no difference.
DR. POWERS: It seems to me, Ellen, maybe you get around
this by bringing up this, the fact that when you use "likelihood," you
are not looking for a quantitative estimate that might be implied
inadvertently by use of the word "probability." And you get around
Graham's legitimate point that if you are making a change for no
purpose, but, in fact, I think you are making a change for a purpose
here.
MS. McKENNA: Yes.
DR. POWERS: I mean I get the sense that you are, and
correct me if I am wrong.
MS. McKENNA: I think it is explaining a little bit perhaps
what we meant by the words, like on the clarity of getting to the --
DR. POWERS: In fact, I would suggest that you draw upon
what Professor Apostolakis said, that is probability theory, likelihood
and probability are identical concepts, but in the common usage one
might be considered to imply a quantitative estimate that is not looked
for here and, therefore, you have substituted likelihood for
probability.
MS. McKENNA: Yeah, I think that is exactly what was the
thinking in that.
DR. WALLIS: Well, I think you have to be clearer than that.
You have to say we have changed it because we are not looking for a
quantitative estimate, not to apply to what some vulgar person might
assume. That is the most preposterous way of trying to write a
regulation, on the basis of what some vulgar person might assume. You
have got to write it so it is clear to everybody, including a vulgar
person.
DR. APOSTOLAKIS: I think you can add something to what Dana
said, which I like to elaborate on that point, that it is the intent.
DR. WALLIS: I will take a vow of silence on frequency,
probability and whatever the other word is.
DR. POWERS: Please don't. The chair denies you the right
to take a vow of silence, sir.
DR. APOSTOLAKIS: Okay. So you are taking out those two
words for clarity.
MS. McKENNA: Yes.
DR. APOSTOLAKIS: And you are adding -- did you take all
that down? Oh, the transcript.
MS. McKENNA: I hope so. We can get the transcript,
certainly.
DR. BONACA: The other thing, again, to close the other
issue, my suggestion was that, again, like in that statement, you would
have -- on page 36, you would say changes within validated requirements,
for redundancy, diversity, separation, other such design characteristics
would require prior NRC approval. You don't have to identify the
vehicle by which. Otherwise, you become technical and it creates
problems. And I would suggest that you look at other parts in this
document of description where you have the same thing.
So you are achieving what you have to achieve, but you do
not call in the technical evaluation. Granted, now, the likelihood word
is helping there, but I think that would be clarifying and helpful.
DR. APOSTOLAKIS: I really find those mental acrobatics in
--
DR. BONACA: Have you heard of conditional --
DR. APOSTOLAKIS: Root cause, we are using probability.
DR. BONACA: Have you heard of conditional likelihood? Can
you say that? Conditional likelihood.
DR. APOSTOLAKIS: It is kind of distorting.
DR. POWERS: Moving right along.
MS. McKENNA: Yes, moving along. So what I wanted to spend
--
DR. POWERS: Wait till we get to the substantive part of
your discussion.
[Laughter.]
MS. McKENNA: What I wanted to spend a few moments was to go
through what were called criteria 7 and 8 and that is if you look
through the package, you see that we started out with three criteria in
the existing rule, some of which are fairly complex in terms of their
formulation, and we split those into seven in the proposed rule, and the
seventh one was the criteria that was replacing the current reduction in
margin of safety as defined in the basis for any tech spec.
And as it is discussed in the course of figuring out what
are we going to do instead of using that phraseology, we came to having
two criteria to try to deal with kind of complementary aspects of
margin, one being the question of the limits that are established for
which the facility has to meet that, and the other being the margins in
how you demonstrate that you are meeting the analysis piece of things.
So we broke them into two pieces to be a little more explicit rather
than trying to back door it out of whether it is a margin of safety and
whether it is defined in the basis for any tech spec.
Criterion 7 says that NRC is required for a change, test or
experiment if it would result in a design basis limit for a fission
product barrier is exceeded or altered --
DR. WALLIS: I'm sorry, on page 3 of the document, the fat
document, you defined design basis limit. Is it defined in the rule?
MS. McKENNA: It's not defined in the rule.
DR. WALLIS: How do we know what it is if it is not defined
in the rule?
MS. McKENNA: It is discussed in the statement of
considerations and will be discussed in the guidance.
DR. WALLIS: Okay. It is discussed on page 3 and it is
defined on page 3 --
MS. McKENNA: In the paper?
DR. WALLIS: I am on the fat paper, page 3. My notes refer
to --
MS. McKENNA: Yes, there is -- I think you are in the SECY
paper, the Commission paper, page 3, I think is what you are referring
to. Yes, that's fine.
DR. WALLIS: It is a page 3 --
MS. McKENNA: Yes.
DR. WALLIS: And it says design basis limit -- the numerical
value of a parameter --
MS. McKENNA: Right.
DR. WALLIS: -- is set at a point at which confidence in the
capability of the barrier begins to decrease. Now that to me doesn't
mean anything. I mean if something which is at some level and then it
begins to decrease, it's like being on top of a mountain and you begin
to go down the mountain --
MS. McKENNA: Yes.
DR. WALLIS: How far do you have to go before you have begun
to go down the mountain?
MS. McKENNA: I think you need to back up to the first
sentence, which is that it's the controlling value that has been
defined, established for that particular parameter, and that is what the
limit is.
The second part is explaining how we usually get to setting
that value.
DR. WALLIS: A design basis limit if it is agreed to by both
parties that it is "x" then we know that that is "x" and you don't go
above that.
MS. McKENNA: Right.
DR. WALLIS: But if it is defined in this wishy-washy way
about it is a place where someone is confidence in some capability
begins to decrease, that is another one of these qualitative things that
means nothing.
MS. McKENNA: But the sentence on the definition is that it
is the controlling numerical value for the parameter established during
the review -- exactly what you said -- and it is presented in the FSAR,
so the licensee presents what it is.
DR. WALLIS: So there is agreement at some date between two
parties as to what it is --
MS. McKENNA: As to what the values are going to be of how
you determine for that particular parameter, whether it is pressure or
whatever the parameter is of interest, how you know that your barrier is
going to be maintained.
The sentence we're referring to was saying this is how in
concept you would get to that value as you set your limit at a point --
DR. WALLIS: Yes, but you see, let's take an analogy. It's
like saying that, talking about the point at which the confidence that
the President of a country under attack by the United States has --
begins to think that the capability of his defensive barriers begin to
decrease. That is such a vague thing.
Those sorts of words should not be in regulations or even as
prefaces to regulations. The point of regulations is clarity. Isn't
it?
MS. McKENNA: What we were trying to indicate was how these
values are typically developed and you develop from the point of view of
there's some condition or state where you don't want to be and then you
want to set your limit at a place that you are well satisfied that you
are not going to be in that unacceptable condition.
DR. WALLIS: But we lack confidence that this had been
determined in a way that was not too equivocal and vague.
DR. KRESS: Well, there's only three of these in that first
bullet.
MS. McKENNA: Well, I think, you know, that was only meant
to be explaining how you get there. I think establishing what the
values are is very clear and the values that we are talking about I
think are also clear.
DR. KRESS: Everybody knows what those are and how they are
established.
DR. BONACA: And most of them are in tech specs.
DR. KRESS: They are in the tech specs.
MS. McKENNA: Many of them are. Yes, yes.
DR. BONACA: I agree that the fact that the tech specs helps
understand what the meaning of this phrase is.
[Laughter.]
DR. BONACA: That would be somewhat obscure but --
DR. WALLIS: But to someone who reads it and doesn't know
just where to find it and finds a definition like this, I find it is
disconcerting.
MS. McKENNA: That sentence was not meant to be part of the
definition. The one sentence was --
DR. WALLIS: But it is part of the public record now, isn't
it?
MS. McKENNA: Yes. I am just saying that it was not part of
the definition. We can look at that as to whether we think it is
helping or hurting the explanation I think perhaps would be the solution
I would propose to make.
DR. KRESS: You may just strike that sentence down.
MS. McKENNA: Yes, maybe if it is not helping it would be
worth just seeing whether we can live without it, which we may well be
able to do.
DR. KRESS: I don't see that it helps anything.
MS. McKENNA: Okay, we are tracking to Criteria 7 and I
think I covered the first bullet. I mentioned the second bullet.
DR. KRESS: Well, except the bullet, I am not sure what you
say in the rule, but the bullet doesn't specify by whose calculational
methodology.
MS. McKENNA: No. That's correct. That's why we have
Criteria 8, which is specific on the methods.
DR. KRESS: Criteria 8 is the one that does that.
MS. McKENNA: That's correct, and this is really more
looking at the changes to the facility and how do they affect the
parameters and the response to the barriers.
Generally when you are looking at these things, you're
right, there is some kind of analysis in there somewhere, but the
premise of applying Criteria 7 is that the analysis is maintained. You
just say what is the change I am making and how does it propagate
through my analysis.
DR. KRESS: It maintains the analysis --
MS. McKENNA: Correct.
DR. KRESS: -- that was originally used in the FSAR.
MS. McKENNA: That's right. That's right.
DR. KRESS: In other words, this is basically Commissioner
Diaz's approach to margin, as I recall it?
MS. McKENNA: I have to think through that one. I think it
is in the sense that you look at the results of the analysis and if that
is what you mean I think -- the reason I was hesitating, I believe
Commissioner Diaz had suggested we drop the criteria altogether --
DR. KRESS: Yes, that was one of his suggestions.
MS. McKENNA: Yes.
MR. BARTON: Eileen, on Criterion 7 --
MS. McKENNA: Yes.
MR. BARTON: -- on page 59 of statement of considerations
package, you have got words in there that the changes that involve
alteration of design basis limit for fission product barrier involve
such a fundamental alteration of the facility design that change even in
the conservative direction requires NRC approval.
MS. McKENNA: Yes.
MR. BARTON: Why even in a conservative direction? Isn't
this essentially a zero increase --
MS. McKENNA: This is changing the limit itself.
MR. BARTON: Okay.
MS. McKENNA: It is not changing the facility and how it
propagates to the limit. It is if you are really going in and saying,
you know, that my reactor coolant system pressure is not going to be
2500 anymore, it's going to be 2300. The reasons you would do that,
there's something more fundamental happening and so we expect that to be
a very rare circumstance.
[Laughter.]
MR. BARTON: I would think so.
DR. SHACK: That's why we have the exceeded or altered --
MS. McKENNA: Yes.
DR. SHACK: It's for that extraordinarily rare circumstance.
MS. McKENNA: Right, correct, right.
DR. BONACA: Usually you want to know why.
MS. McKENNA: That is exactly right, yes.
DR. APOSTOLAKIS: You are not going to deny it?
MS. McKENNA: Well, I mean it's --
DR. SHACK: We need to hear the reason first.
MS. McKENNA: I think the reason is the thing of interest.
Something has changed in our understanding of where things are going
so --
MR. BARTON: Okay. I understand that now.
MS. McKENNA: Okay.
DR. WALLIS: Are you going to get sometime onto the 10
percent of the remaining margin question?
MS. McKENNA: I wasn't planning to speak to that in detail
but if you have a question I certainly can do that.
DR. WALLIS: Well, this seemed to be a definition of
minimal. Minimal starts off being vague and then there is a discussion
about how well -- it's sort of compatible with the negligible idea of
NEI, and then there's a separate definition about it being 10 percent of
remaining margin.
MS. McKENNA: We were giving guidance in the rule on how to
apply the minimal increase to consequences.
DR. WALLIS: I like the idea of being specific.
MS. McKENNA: Yes.
DR. WALLIS: I like the idea of the examples you have.
MS. McKENNA: Yes.
DR. WALLIS: Very helpful.
MS. McKENNA: Thank you. In the consequence areas I think
we felt we could do a better job of really getting to specifics about
how to deal with minimal because --
DR. WALLIS: What bothers me is there's a logical problem
between something which is negligible and something which is 10 percent
of a remaining margin.
If something is 10 percent of a remaining margin, it's
certainly measurable and certainly not negligible.
MS. McKENNA: Well, the term we are using is minimal.
DR. WALLIS: It may be what you accept, but be careful of
things which aren't consistent. If at one point you are saying, well
minimal and negligible are close enough that they are good enough --
MS. McKENNA: No, no, no --
MR. BARTON: No, no, no, no -- we said don't use negligible,
use minimal, and they are defining minimal and then getting 10 percent
of minimal.
DR. SHACK: Anything that is negligible is minimal.
MS. McKENNA: Is minimal, right.
DR. POWERS: And I might just comment that there is quite a
lot of examples in law where 10 percent has been declared a minimal sort
of thing. I mean it arises several times and in fact within the
Department of Energy we got in a judgment from GAO that 10 percent would
be declared quite small.
MR. BARTON: Right, correct.
DR. WALLIS: Well, I think it's quite small, but would like
to have it specified rather than vague and of course the criticism we
have made is that minimal was too vague a statement.
It is just that was this NEI proposal and we urged you to
get together and sort of compare those and so on and then we'd sort of
say that well, because their negligible is less than our minimal they
are not proposing anything bigger than we are going to allow, so it is
okay, but that made it -- made me a bit troubled anyway about this 10
percent.
MR. BARTON: Do you still have that disagreement with NEI?
MS. McKENNA: I am not sure I would characterize it as a
disagreement.
MR. BARTON: Well, they use the negligible, which they
wanted to use, versus minimal. I think they have now come on board --
MS. McKENNA: Well, I think as Dr. Shack was mentioning, we
all agree that if you are meeting the negligible you will meet minimal.
The issue has been can you move beyond it and can we agree on what that
means?
MR. BARTON: Have we agreed now on what that means?
MS. McKENNA: Well, I think we have had some discussions and
we think there may be room for further discussion and we may be able to
in the guidance are supplement with -- come up with four examples on how
to deal with malfunctions and things like that. That will help. I
think we may have to do it more that way rather than, you know, at 10
percent or something like that.
DR. SHACK: Yes, I think it was always in the context of the
existing guidance --
MS. McKENNA: That's correct.
DR. SHACK: -- to define negligible and therefore you could
use it within the context of the new rule.
MS. McKENNA: Exactly right, yes.
DR. SHACK: The question was how you were going to go
further, but at least you had established you could use the existing
guidance.
MS. McKENNA: Absolutely.
DR. BONACA: A comment I have on the design basis limit.
Words should be there to make sure that that barrier is maintained I
mean not only by maintaining the lower limit but also the upper limit.
For example, containment design pressure clearly is the
limit.
MS. McKENNA: Yes.
DR. BONACA: Internally. But you are going to affect the
barrier by changing -- for example, you put rupture disk as we did on
the Harden vent and you go down, the failure of your containment at the
design pressure or just above that, so you have reduced really that
barrier as a margin of safety.
Is there a provision in there? Is the word "altered"
referring only to the design basis limit or also to the barrier?
MS. McKENNA: Well, I think if you were altering the barrier
such that the limit is no longer the right limit, which I guess is maybe
what you are saying, I think that that would also fit in that.
DR. BONACA: Well, let me give you an example. Suppose that
you did not mandate the Harden vent but I did choose on own to put a
Harden vent. That would cause the pressure disk to rupture right above
the design limit so that pressure in the containment goes up to the
limit, 50 psi for example, and then it goes just above that, the rupture
of the disk, and so now the barrier is gone.
I have literally eliminated a margin of 80 psi, 90 psi,
something like that, in the barrier by affecting the outer limit rather
than the inner one.
MS. McKENNA: I think the way we had structured it, we
weren't trying to capture that kind of situation with this criteria. I
think you might have to look at other criteria if you were in that
situation where --
DR. BONACA: But I think all you have to do is to make sure
the word "altered" refers to the barrier rather than the specific design
limit that you are looking at, because the way I read it, it doesn't do
that and I am only saying, you know, it doesn't happen often but that is
an exact example of where you may affect a barrier by simply taking out
this upper range of capability by design.
MS. McKENNA: I will have to think through that one, but I
understand what you are saying.
DR. BONACA: I mean that came from the NRC, therefore you
even have to do a 50.59, but normally --
DR. WALLIS: Now this minimal is in the rule.
MS. McKENNA: Yes.
DR. WALLIS: But the 10 percent part is in some other
document.
MS. McKENNA: It is in the statement of considerations which
is published along with the rule.
DR. WALLIS: It needs to go with the rule otherwise it
doesn't make enough sense.
MS. McKENNA: Yes, and then it will also be in the guidance.
DR. WALLIS: Now is 10 percent then the test which the
licensee will apply in determining whether or not the change is
minimal --
MS. McKENNA: Yes.
DR. WALLIS: -- or are there other tests that will be
applied?
MS. McKENNA: The consequences, that would be the test that
would be applied.
DR. WALLIS: The one and only and sufficient test for all
changes?
MS. McKENNA: As I said, when you are looking to see whether
the change you are making, how it has affected the consequences, that
would be the standard that you would use to address.
DR. WALLIS: So why isn't something like 10 percent written
into the rule instead of the minimal put into the rule and then you have
to go somewhere else to find out what it means?
DR. KRESS: Because it's hard to change a rule and it's easy
to change the reg guide.
DR. WALLIS: So what might happen is that minimal might be
interpreted some other way in the future? Is that the idea?
MS. McKENNA: It's possible. I mean, I think the thinking
was to put --
DR. POWERS: When it's in the statement of considerations
it's very difficult to go back and change that.
DR. KRESS: That's part of the rule.
MS. McKENNA: I think that it is trying to keep the thought
process in the rule and then the specifics of how you do it.
DR. WALLIS: Suppose somebody who is, say you're a Member of
ACRS, wants to know what does minimal mean, read the rule. Is there any
way that that naive person knows that he has to look somewhere else to
find what minimal means?
DR. POWERS: I think anybody that is in the business of
acting upon these rules knows enough to check the statement of
considerations and the guidance.
DR. WALLIS: That may be true there, but it wouldn't be true
of this Member of the ACRS I'm referring to.
DR. POWERS: With our superb staff, he would be acquainted
with it and supplied with more documents than he would care to have to
plow through.
DR. WALLIS: You see, that's what I'm trying to avoid. I
say it should be clear, if someone wants to know or some reasonably well
informed person wants to know in order to clarify something or work
something out, what the rule is, he shouldn't have to be an insider and
know all the tricks of the trade in order to be able to figure out what
the words are supposed to mean. So that you have to look at something
which you have to know exists in order to find out where the definition
is. It seems to me much more preferable to have it in the rule itself.
That's again, that's a naive relatively new junior, as George points
out, Member, trying to figure out why it's done this this way.
DR. POWERS: It is certainly an area of curiosity, but it is
also true of many, many of our rules that to really understand them, you
really have to go to the guidance, and sometimes to the standard review
plan to understand what it is that the staff is prepared to accept to
fulfill the words.
DR. WALLIS: Let me say that's my -- that's followed me
since I joined the ACRS, that something which looks like a very simple
principle or rule suddenly turns into thousands of pages of
documentation before it can be used.
DR. POWERS: I think that's the --
DR. WALLIS: That's very peculiar.
DR. POWERS: I understand exactly what you're wrestling
with. I wrestle with a far more difficult set of rules myself. That's
the 800 series of 10 CFR. And it has always been my impression that the
controversy you run into here or the difficulties you run into here is
that you have a legal system with one set of language and you have an
engineering profession with a different set of language, and the two
have met here in these kinds of rules and the decision has been that
it's the legalese that makes it to the rule and it's the engineerese
that makes it to the guidance and the standard review plan. That has
been my interpretation. I agree with you, it would sure be nice if you
had one set of language that we all can agree to. But it seems to be a
challenge.
DR. WALLIS: Well, it's not just a question of nice. If
it's desirable that there should be less in the way of reg guides,
because the rules are so simple and clear, I think that's something we
should work towards. We shouldn't just say it's always been this way,
therefore it should stay this way.
DR. POWERS: Well, I think what we find to the contrary is
that it is more useful to have more reg guides and fewer rules. Like I
say, my experience all comes from the 800 rules, and they are -- and we
don't have reg guides. And so we invent lots of things that look like
reg guides to try to tell us what the rules mean. And I think that
works out to everyone's advantage. Few rules that are rather broad and
the reg guides don't tell in our case here at the NRC the licensees what
they have to do. They tell them here is one way to satisfy these rules
the staff is prepared to accept on face value, okay? You can do it any
way you want to, but if you do it this way, the staff is prepared to
accept this. And the standard review plan will review this in the
following way. And I think that's in comparison to what we have in the
800, that's a very nice way of doing things.
DR. KRESS: Yes, I think there's a better explanation of why
they're separate, too. It allows flexibility. If it were written into
the rule, it would be part of the rule.
DR. POWERS: Yes.
MR. MATTHEWS: One of the concerns the staff's been trying
to respond to is that we have been dealing in the former rule with an
interpretation that said may be increased as a zero standard, and
there's issues of precision that come into play in establishing whether
zero has been established or reconfirmed, and our concern with putting a
numerical value in the rule is just the same kind of argument, which
side of a very narrow line are you on, and there was a desire for some
flexibility. The 10-percent value in guidance or in the statement of
considerations is, you know, on the order of 10 percent.
DR. BARTON: Right.
MR. MATTHEWS: Okay. To which we're not going to apply a
magnifying glass. If we were to put it in the rule, trust me, a
magnifying glass would be applied. So, I mean, it is an issue of
philosophy, and I agree with the concern that we ought to be as literal
as we can, but in some areas, there isn't a benefit to being that
literal.
DR. POWERS: And I think the lawyers advise us that we tread
on dangerous ground when we put numbers in, and experience shows us
certainly the experience of the EPA has shown us that the science gets
better, the rule stays stagnant, you create real headaches when you've
gone to quantitative limits. I think that's been our experience.
DR. WALLIS: But the naive position of the public would be
that the rules ought to be simple and having huge piles of paper and
procedures is simply making work for regulators.
DR. POWERS: Well, I can appreciate that point of view, but
the truth of the matter is that what they're doing is giving engineers
the guidance they need to do their job.
DR. APOSTOLAKIS: Let me understand this. Is the rule
similar to a law passed by Congress and the decisions of the various
courts are interpretations of the law --
DR. BARTON: Yes.
DR. POWERS: Exactly so.
DR. APOSTOLAKIS: And these are the regulatory guides?
MR. MATTHEWS: That's my concept.
DR. BARTON: That's it. And I don't think we're going to
change it as a result of this meeting, and I think we need to push on so
we can figure out what's changed in this rule so we can prepare a
letter.
Eileen, please.
MS. McKENNA: Okay. Thank you. So we're talking about
criteria 7 on the fission product barriers. In the last bullet I just
was indicating that in terms of for implementation, changes that are
being looked at would be changes to the facility, systems, structures,
components, and procedures, and that in applying these criteria you need
to look at how those changes are affecting the parameters and then
compare whether the limits continue to be met as a result of the change
that's being made.
DR. KRESS: That last bullet's to cover design basis limits
that are additional to the ones --
MS. McKENNA: It's to cover the fact that, you know, your
limits apply to let's say the reactor coolant system --
DR. KRESS: Yes.
MS. McKENNA: But you may be changing something in an
entirely different system that may have an effect through the way -- the
function of that system on the reactor coolant system, that you need to
look at how that effect ends up with respect to how the barrier
performs.
DR. KRESS: Well, you've already covered that --
MS. McKENNA: Yes.
DR. KRESS: In the first bullet, though. I thought it had
to do with --
MS. McKENNA: This is not something in the rule. This is
just explaining in the guidance of how you would go about starting from
here's the change you're looking at and how do you then move forward
to --
DR. KRESS: Oh, okay. I see. That's how you would be
sure --
MS. McKENNA: You meet that. Correct.
DR. KRESS: Meet that first bullet. I got you.
MS. McKENNA: Right. That's all.
Okay. As I mentioned, the other criteria, criterion 8,
which is specifically looking at changes to the evaluation methods
themselves, and what -- the words in the rule talk about departure from
the methods in the FSAR used in the design bases or in the safety
analyses to try to clarify which methods we're talking about that we
feel this criterion should apply to, and then we use the word
"departure" because we think there's a couple of attributes, if you
will, to when it is a departure, and there are really two parts. One is
if you're changing some part of the method and how that affects the
results of your method.
And the second is if you have one method and you want to
change to another method that has already been reviewed and approved for
that particular use, that that would be acceptable since it has already
received the review that this criteria in the rule is trying to look
for. So that there is really the two elements, that if you change it
and kind of -- you get the same answer or --
DR. POWERS: Is this asking for troubles for the staff?
When they approve a method for a particular plant which may have unique
features and whatnot, that they have to bear in mind that this method,
without proper -- their approval, has to have with it the codicils of
all the things that led them to approve it for this plant and say and no
other plant, that there is an --
MS. McKENNA: There is an element there that we have to be
careful of. What we have said in the discussion is that when the
licensee is doing this evaluation and looking to see, well, can I change
from method A to method B, they need to look at whether the method was
-- I think we used the word "generically approved" for, you know,
whether it is PWRs or for non-LOCA transients or whatever the usage is,
and do they fall within the terms of what that approval was. And, yeah,
there may well be cases where the staff looked at it for plant X, and
only for plant X, and that was as far as the SER covered, and then plant
Y may not be able to use it under this criteria.
DR. POWERS: But I mean I guess -- I am not sure who the
burden falls on here. Is it the burden on the staff to, when they
approve a method, to say, and in the course of developing this approval,
we took recognition that this plant is a 2 loop PWR manufactured by
Babcock and Wilcox in a subatmospheric containment, built on Wednesday,
and no other plant? Or is the burden upon the licensee to say, aw, the
staff approved this, but when doing so it was only for 2 loop
subatmospheric B&W plants?
MS. McKENNA: Well, since the process we are talking about
is for a licensee making changes on their own, the burden is on the
licensee to establish that, if they are using this new method, it is --
it meets the conditions that were established for it. And if the only
-- if all the SER said was it is okay for plant X, that is not going to
give a licensee any basis necessarily for being able to say that it is
okay for me too, because you are not going to be able to make that kind
of conclusion.
MR. MATTHEWS: This was a point of discussion between
ourselves and the industry. They were hopeful that we could see our way
clear to include a criteria that would permit them to translate methods
approved on one individual plant to methods approved for another similar
plant, and the technical staff was of the view that they didn't have
that kind of restriction, mindset, or didn't impose limitations on their
review that would permit the extension of one plant's approval to
another one. So the staff was reluctant to allow the industry to, in
effect, make liberal use of approvals on similar plants.
So this did come up as a point of discussion. The resulting
outcome was that if the approval by the NRC on its face and in the
literal wording of the staff's SER extended the method to the plant in
question, then that method could be used.
If it was silent, and it was a plant-specific approval, it
couldn't be inferred to have generic applicability, and the tech staff
was very adamant about that, because they didn't look at it for generic
applicability. And if they were to look at those individual amendments
with the expectation that somebody may use them generically, the review
on an individual plant's amendment would be much more burdensome.
MS. McKENNA: I think we are recognizing that there are
cases where the staff does look at things topical, that is generic and
that that is what -- the kind of cases we were talking about.
MR. MATTHEWS: So I think the burden, in summary, the burden
is on the licensee, in applying these rules, to be able to demonstrate
unequivocally that the method has been approved for the plant in
question. However, I think the staff continues to need to be mindful
when they make a generic approval that they make sure and limit just the
extent of that approval in terms of types of plants and conditions under
which it can be applied.
DR. POWERS: Well, I think when they do a generic, they are
pretty --
MS. McKENNA: They are careful to do that, yes.
DR. POWERS: They are pretty good, but they are not -- when
they do an individual plant, I don't think they think about it.
MS. McKENNA: No.
MR. MATTHEWS: No.
DR. POWERS: And I don't think we could ask them to.
MS. McKENNA: No.
MR. MATTHEWS: No. And I don't think we would to. And I
don't think individual licensees would want that either because it would
impose an additional regulatory burden that would be undeserving on an
individual applicant.
DR. POWERS: One of the things that you have to recognize in
writing this rule is that many of the FSARs were written in the days of
the slide rule.
MS. McKENNA: Yes.
DR. POWERS: And the changes are being made in the days of
the PC. And so if I come in and I have done an analysis, say, for
example, the FSAR method, what has been used and reproduced for years
now was done, say, with an Eulerian model for solving a differential
equation. And now because I have got a PC, I say, gee, I want to use a
Runga Kutta, much more accurate, much more refined. Is that one of
these -- is that considered a change in the method?
MS. McKENNA: It would really depend I think on -- as we
indicated, you have to look at what is in the FSAR and, therefore, what
information was available. Now, whether that level of specificity would
have been included would probably depend on the nature of the analysis
that you are talking about. How important was it that it be -- whatever
the indicated -- I am not familiar with the specific example you used,
but if that was something that would have really been significant with
respect to the particular analysis and how it was being used, and,
therefore, was presented.
DR. POWERS: Well, it is an example out of a specific FSAR,
so --
MS. McKENNA: Okay, then --
DR. POWERS: I mean I just happened to notice that they
solved it by an Eulerian method.
DR. KRESS: What it likely will do is give you a more
precise calculation of the design limit.
MS. McKENNA: Yes.
DR. KRESS: I mean how close you are coming to it.
MS. McKENNA: yes.
DR. KRESS: And in this case, it probably lowers the
calculated value.
DR. POWERS: Yes.
DR. KRESS: So they could say they have more margin now.
DR. POWERS: Yes. Yes, that would be --
DR. KRESS: Yes. And I have a question about that. Were
you through, Dana?
DR. POWERS: I am pursuing this issue, and I guess I don't
have an answer.
MS. McKENNA: But that is exactly the reason why this
criteria was there, is that if you are saying, well, we looked at -- the
staff had looked at the facility and the analysis in a particular way,
and now you are saying under criteria 7 you are allowed to change a
facility and now go right up to what those limits are.
DR. KRESS: But I would have assumed -- you had a criterion
from here --
MS. McKENNA: Yes.
DR. KRESS: -- that would say if this change to your
calculational methodology makes a significant change in your calculated
answer that you had before, then we need to look at it, whether it is up
or down.
MS. McKENNA: And that is what we are talking about, being
that you either -- you are either the same -- basically, you have the
same answer you had before.
DR. KRESS: Yes, but that is within some percentage of
something.
MS. McKENNA: Within, yeah. Within --
DR. KRESS: So that is the way they would view that, I
think, Dana, as -- did it change the answer very much? And, if so, we
look at it.
MS. McKENNA: Right. If it didn't change the answer very
much, then fine. But if it did change the answer more than, well, a
little bit --
MR. MATTHEWS: So it isn't essentially the same.
MS. McKENNA: Right.
DR. KRESS: Let me ask you an additional question about that
then.
MS. McKENNA: Yes.
DR. KRESS: What you have is you have these design basis
limits, and you have a calculated value.
MS. McKENNA: Right.
DR. KRESS: Based on some sort of a plant-specific,
licensee-specific code.
MS. McKENNA: Correct.
DR. KRESS: And you have reviewed these both and approved
this code and this design basis limit based on this calculated value.
And I guess you are calling that margin now that can be -- that they can
make changes. As long as they don't change this code, they can make
changes that incrementally approach this limit.
MS. McKENNA: We are allowing -- what we are saying is that
we have reviewed how you show you meet the limit and what the limit is,
we will let you make changes to a facility that bring you up to that
limit, as long as you show that you are still meeting in the same way,
so we understand how, you know, what that --
DR. KRESS: But I assume the original approval of the
methodology had implicit in it the fact that you had this margin as a
result of the calculation, to account for the uncertainties associated
with that calculation methodology. Now, you are going to let them eat
it away all the way up to the limit. And in my mind, that means you
have probably -- may have exceeded the limit as some probability because
the uncertainty is in both directions.
I don't know how you dealt with that in coming to this type
of --
MS. McKENNA: Well, I think the thinking was that when these
limits for the barriers were set, there was account for uncertainties.
You set them at a point that you knew that that was not the point where
the barrier was going to fail. You set it some distance away so that
you have some accounting for variability.
DR. KRESS: Typically, 10 percent of the design value.
MS. McKENNA: Well, I think -- when you say -- you are
talking about some of these parameters, I think there are some times you
are talking about factors, you know, orders of magnitude in some cases
between where you set your don't exceed this and where you really think
that the containment or your reactor coolant system is going to fail.
DR. BONACA: One thing that was typical, Tom, like they were
really surrogate analysis. They really were not analysis. So wherever
you got the point kinetics calculation for reactivity transient, and you
forced some performance there where you would by far exceed any, you
know, steep slop, and the reason is that you were trying to set your RP
set points up there, so you wanted to do them, you know, as low and
conservative as you could.
DR. KRESS: Yes.
DR. BONACA: So those are really artificial, and they were
all skewed in one direction, depending on what set point you were
setting. That was the concept behind --
DR. KRESS: Yes, that is the issue -- we did the calculation
in the first place in a conservative manner.
MS. McKENNA: Yes.
DR. KRESS: Therefore, the real answer is somewhere down
here. That doesn't address my question because the uncertainties may be
so large than there is a high probability that answer could be still up
here, even though it is conservative. You know, that doesn't -- it
doesn't really address my question is the problem with it.
DR. BONACA: No, I was explaining why I was -- the concept
of --
DR. WALLIS: Well, I think I have the same concern Tom has.
I think when you start eating away margins it should be done based on
some sort of better understanding of what you are doing, because the
margins were there originally on the basis of someone's judgment because
things weren't definite, there were uncertainties, they were put in to
allow a margin. And if you can show that, because we know how to do
things better today, there are justifications for not being so cautious,
then there will be a more reasonable explanation for why it is being
allowed to eat away the margin.
MS. McKENNA: Well, I think that is why we are saying that
-- we are not saying that using these other methods would be
unacceptable. We are saying that the staff would want to have the
opportunity to review those methods for those reasons you are talking
about.
DR. WALLIS: See, my suspicion is that 10 percent has just
been pulled out of the air.
DR. KRESS: Yeah, we are addressing the 10 percent.
MS. McKENNA: Oh, okay.
DR. WALLIS: The 10 percent is pulled is being pulled out of
the air as something politically acceptable with no technical
justification whatsoever.
MS. McKENNA: Okay. You are back on --
DR. WALLIS: Which is fine. That is probably how
regulations get made.
DR. KRESS: That is our issue, the justification of the 10
percent.
MS. McKENNA: Okay. Well, the justification -- the 10
percent really is applying in the area of consequences where we are
saying there are -- these are regulatory values that have been set and
we want to approach them in a step-wise point rather than going to --
DR. WALLIS: The way it has been derived is simply --
correct me if I am wrong, by people sitting around and saying, well,
what should we choose? Well, 5 percent, 10 percent, 20 percent, what
will people buy? What is acceptable to all sides? Well, probably
people will buy 10 percent, let's talk about it. And then it is
accepted, but it is accepted, therefore, I would say in a political way.
It is not accepted on the basis of any rational decision making, on the
basis of better definition of what a margin is, under what grounds it is
justifiable to erode it, how it is really related to the effect on
public safety. Because it has been deduced. It is based more on just
people sitting down and saying let's choose 10 percent.
Now, if that is an acceptable way to make decisions, that is
perhaps the way to do it. But it seems that perhaps there is a better
way.
DR. BONACA: If I can give some insight on the point. If
there was a tendency to increase -- to eat the margin because it is
useful for something, I would say I completely share your feelings. The
experience I have seen, reviewing literally hundreds, if not thousands
of safety evaluations is you are dealing more with minor changes that
are resolved by a small input that you have somewhere, like, you know,
you have a temperature error, you assume your calculation is 2 degrees
Fahrenheit in that direction, and now you have 3 degrees Fahrenheit and
you want to see what the sensitivity of the result may be. And you get
a result where you get maybe a couple of PSI higher pressure in, for
example, in transients.
And the issue is, should you go now and ask for us to review
a cycle, the whole process, or should you have that margin to allow for
that?
Now, yes, we have to be sensitive about whether that was a
creeping effect that would go then into regions where you shouldn't go.
But, you know, pragmatically, that has been the experience that I think
--
MS. McKENNA: Yes, I would confirm that. Certainly.
DR. BONACA: Under the NEI, I mean NEI came up in 1989 with
-- 25, and, really, you haven't seen any erosion or that sense, I mean
because that is what has been evaluated. In some cases you have
changes, it will be down. In some cases the change is up. And so I,
from that perspective, I think it is pragmatic. I realize that there is
always some vulnerability. But I think it is in the right direction,
just an opinion here.
MS. McKENNA: I think that is a fair statement.
DR. POWERS: Go ahead.
DR. KRESS: I have an unwritten rule and that says if a rule
allows something, eventually it will happen.
MS. McKENNA: I mean that is -- we have to approach it from
that point of view, too. And I think that is why we were trying to do
this two-pronged approach of saying, okay, continue to meet the limits
and continue to show that you did it in the same way, so you don't have,
you know, eating away at the limits and eating away at how you did it,
so there is a much greater chance that you are above. Yes.
DR. KRESS: I see you have got your limit controlled. I see
you have got your calculational methodology controlled. What I have
seen is you have lightened up on your margins and are going to let them
eat away at it.
MS. McKENNA: That's right.
DR. KRESS: And I haven't seen the justification for that
yet.
MR. MATTHEWS: To give them more flexibility to be able to
work within an arena that doesn't involve the NRC.
MS. McKENNA: And I think the other --
MR. MATTHEWS: And the NRC, in doing that, is giving up some
of the prior oversight and control for those kind of changes. And that
is -- I think we have to say that, you know, across the board.
DR. KRESS: That is a reason, it is not a justification.
MS. McKENNA: No, I think the justification is that we have
-- it was mentioned earlier, in certain things that we have carved down,
say, that we put in the tech specs, and say these things, you don't have
the flexibility on, they are protected. Saying the limits, you have to
meet those limits. These were limits that were agreed upon as being the
appropriate values for those parameters and those have to be maintained.
But those limits are being met when you make these facility
changes and if you then are still meeting those limits that we have
established in a conservative place, I think that is the basis why --
DR. KRESS: Say you could give that flexibility a number of
ways. One -- 5 percent or 2 percent -- and you could have said oh,
well, we are going to take the design limit and we are going to drop
below it 10 percent and let you just go up to that. There have been a
number of ways you can give this flexibility and I don't see any
justification for any of them.
I mean you have to develop some sort of basis for why you
went this way. Why 10 percent? Why going all the way up to the limit
itself? I don't know. I haven't seen the reasons anywhere.
DR. BONACA: What I want to say, there is this performance
indicators that are really an important measure. For example, if you
had seen -- for example, say that you have issues with peak pressure in
the RCS, okay? If you had it creeping up, you would have two things
happening.
One, you would have much more frequent opening up PORVs.
Second, you will have high pressure trips increasing and third you would
have safety valves being cycled.
Now instead we have seen in the past 20 years an actual
large reduction in number of RPS trips, less PORV actuation and really
no safety valve actuation. I mean all I am trying to say is that there
are indicators there in the inspection program that will really come
around, and if you begin to see that kind of creeping up of those kind
of parameters, that is going to be a flag and this is going to come up
right away because you are going to have -- so all I am trying to say is
the reason --
DR. KRESS: The justification might be it is controlled by
other things or something like that.
DR. BONACA: Yes. All I am expressing here is more comfort
that I have maybe than you do have, Tom, nothing else.
DR. KRESS: I really am not concerned about it or I would be
raising some sort of stink.
DR. BONACA: Sure.
DR. KRESS: I think it is perfectly all right to do this. I
just haven't seen the justification.
DR. BONACA: I understand.
DR. KRESS: I think it is there. I think the justification
is there somewhere and I think they have been sufficiently conservative
anyway that let them go up to the design limit --
DR. BONACA: The justification is not there. I do it only
for comfort because I've been tracking this issue of performance
indicators and seeing them actually going down rather than up, and that
is why I have some comfort there, but you are right, there isn't a logic
behind why 10.
DR. WALLIS: And not only justification -- how about the
consequences? I mean down the road what happens when everyone has taken
their 10 percents and the 10 percents and their 10 percents and there is
no margin left? What happens then?
DR. KRESS: You eventually get there, don't you?
DR. WALLIS: What happens then? Minimal becomes zero again.
Is that your intent?
MS. McKENNA: It is not the intent. I think it would be an
outcome of if that was the way --
DR. WALLIS: So was it your intent to have a law which after
awhile goes back to the way it was before, which means minimal becomes
zero?
MS. McKENNA: Well, but I think that under the circumstances
you are talking about where they have moved themselves up to now being
at the limits of the regulatory values in the course of the terms of the
process of saying should NRC be reviewing those changes, if that is
where you are, then NRC should be looking at those because as you just
said you have taken all the margins away.
I don't think that that is the situation we are going to get
to because I think Dr. Bonaca is right.
DR. SEALE: I think disposable margin.
MS. McKENNA: Disposable margin, that is correct, yes.
MR. BARTON: Good point.
MS. McKENNA: That is a good point, yes.
MR. BARTON: Go ahead, Eileen.
MS. McKENNA: I was just trying to finish up on Criteria 8
and I think we have covered pretty much all these points.
MR. BARTON: Excuse me?
MS. McKENNA: I'm sorry?
MR. BELL: Thank you. I am Russell Bell with NEI. I think
I just want to clarify a couple of things.
In terms of the -- taking them in reverse order -- in terms
of the 10 percent on 10 percent on 10 percent, we are talking about
increases, potential increases in dose consequences. In addition to the
10 percent of remaining margin, licensees would also be limited by the
NRC's own -- what do we call them? --
MS. McKENNA: Acceptance guidelines?
MR. BELL: -- acceptance guidelines, which are taken from
the Standard Review Plan. These are already set well below 10 CFR 100
kinds of regulatory limits.
For instance, for many scenarios the acceptance guideline in
the SRP that applies to many licensees is 30 rem thyroid, while the 10
CFR 100 limit is 300, and so I just wanted to make the point that we can
take 10 percent, 10 percent but we have committed to the approach that
we would not -- that we would continue to honor these much lower SRP
guidelines. That was point number one.
Point number two, in terms of the -- and Dr. Kress, I wasn't
going to say anything because you are not really raising an issue, but
you seem uneasy about the ability to go all the way up to a design basis
limit and that we are eating away margins and I just would clarify from
an industry perspective there is really no difference in that approach
than we believe is currently existing in the industry.
The NRC may perceive that they are giving something up but
we have identified perhaps a difference of interpretation on this area
but our view of the longstanding guidance that was produced in 1989 by
EPRI and now is incorporated into the NEI 9607 document is margin of
safety begins above that design basis limit and we have always
maintained and again honored that line, but considered the region below
the line to be some other sort of margin -- operating margin -- that
would be the purview of the utility to use, and indeed that was
typically practiced by licensees.
DR. KRESS: But why do you think that margin above the line
is there for? What above the line?
MR. BELL: Well, certainly the term "margin of safety"
implies that we would -- that describes that region. It is to ensure
that we don't encroach on a failure point.
DR. KRESS: You don't want to get close to the failure point
because you are uncertain --
MR. BELL: Agreed.
DR. KRESS: -- in terms of your calculation and your
phenomenology so it is better to cover the fact that you are really
uncertain as to where you really are and you don't want to get up close
with that kind of uncertainty.
MR. BELL: I think as Eileen put it, I would have given the
very same answer. That was a consideration in where those limits
themselves were established, the 50 psi.
DR. KRESS: And all I was saying is that --
MR. BELL: Very conservatively.
DR. KRESS: -- when NRC looked at the calculational
methodology and approved it based on those limits and approved it
because it calculated at a lower number is because they perceived the
uncertainty in that particular code or the methodology to be more than
they are comfortable with with that design margin, so that in my mind
incorporates it into the margin above, and so you can view that a lot of
different ways.
You know, I agree with you. There's probably more margin.
The reason I am not really concerns is there is probably so much margin
there because of this great distance away from the actual limits and
where you really have a problem that that little bit of difference is
almost like an insignificant change. We're going on up to the limit --
or I agree with you on that, but the problem I have with it, it just
doesn't technically hold together, see?
You know, if it had a good technical --
MR. BELL: Understood.
DR. KRESS: Yes.
DR. WALLIS: Every time a margin is eaten away a bit there
is a consequence to public safety.
DR. KRESS: There's no doubt.
DR. WALLIS: And I think this committee probably agrees that
what you are doing is right, that there is no significant change to
public safety. The effect is minimal, but there is nevertheless a
change and it would I think in this day and age of having measures for
things be very good to have a measure of what is the impact of this on
public safety.
I think that what's happened is the rule gets set by what I
have called this political process of negotiation, people discussing.
It would be good if some professional person could look at it and say
right -- what is now the consequence of making this new law on the
public safety, because margins will be eaten away and that must have
some effect.
DR. POWERS: I am going to intercede here. We are going to
have scheduling difficulties otherwise. Can we finish up in the next
two minutes?
MS. McKENNA: Yes. Actually I think I have pretty much
covered it. I had a slide here on the other regulations but I think I
covered that in the opening remarks other than I'll just comment back on
your question about Part 71.
What you saw in the paper is that the agency is planning to
look at the, if you will, I'll give the shorthand, the 7148 type of
change process for Part 71 as part of a larger rulemaking that they are
doing on Part 71 to look at the compatibility with the latest IAEA
standards. They will look at that as part of that same rulemaking.
I have no other -- there's no other developments on the Part
71 front.
The last slide I had was on the implementation. I think we
covered that in the beginning, that we are -- we will make a proposal.
Exactly what that number will be --
DR. POWERS: Let me make it clear that I think the committee
has expressed in the past its desire that the Staff be capable of
handling application or activities under this revised rule quite
promptly.
MS. McKENNA: Yes.
DR. POWERS: But I think they should be flexible in allowing
licensees, just because of the tremendous amount of training burden that
they will face at a time they may not be prepared to face it --
MS. McKENNA: Right.
DR. POWERS: -- they should be also flexible in allowing
them to move to the new system. Staff itself should be very quickly
able to handle licensees using this new procedure.
MS. McKENNA: Yes. I think the primary thing is we want,
since it is the licensees that have to do the evaluations, they need to
be comfortable. We thought about since it is all relaxation, you could
make it immediately effective and then that raises the question of how
quickly we can get the word out to our own people that these are now the
ground rules, so we kind of steered away from immediate and at some time
longer than that, and exactly how long it is is still I think you could
pick a lot of different numbers.
MR. BARTON: I've just got one question before we break --
MS. McKENNA: Sure.
MR. BARTON: -- and hear from NEI. On page 99 on the
enforcement policy, I question the statement you make -- a failure to
submit an amendment as required would be considered a Severity Level 3
violation if a substantial review is needed by the NRC before it could
conclude that a licensee's actions were acceptable.
And I think that's kind of severe. Can you explain that to me?
MS. McKENNA: Okay. The way the policy is written now, and
examples that are given for 50.59 violations, it says a 50.59 violation
where licensee failed to seek the amendment is severity level 3. That's
the way the policy is now. Over the -- since the last year and a half
when we set up the panel I think it was kind of a recognition that not
all failures to seek licensee amendments are equally significant, so
this was a measure of trying to apply saying, you know, the base idea
would be that failure to seek the amendment is a level 3, but if it was
really not that important an issue, it was one of these minimal
increases or, you know, something not -- the safety significance of the
issue was not that great, that perhaps a severity level 3 was not
warranted for that particular instance, and that then we would
exercise --
DR. BARTON: So why doesn't this say based on the safety
significance of the failure to apply for a change rather than on the
number of hours you're going to spend reviewing --
MS. McKENNA: It's not the number of hours. I think what we
tried to clarify with the parenthetical is the merits of the
technical -- it's kind of if it's so simple that you look at it and you
say well, this clearly meets all the requirements, it's a very
straightforward type of thing that would not warrant being treated as a
3. If it's a more complex issue that the technical review of whether
the change is acceptable is more involved, it suggests that the
underlying significance of the issue is more involved, that that would
be a reason perhaps not to exercise the discretion.
DR. BARTON: Okay. Are there any other questions of Eileen
while she's here?
If not, let's take a break before we hear from NEI. Fifteen
minutes?
DR. POWERS: Fifteen minutes would be fine.
DR. BARTON: Be back at quarter to four.
[Recess.]
DR. POWERS: Let's come back into session. I think I have a
quorum, though they may not be paying full attention.
DR. SEALE: Our chairman is going to roust us if we're not
careful.
DR. POWERS: Let's please go ahead.
MR. BELL: Well, I promise to be very brief, and I --
DR. POWERS: I would hope you would be complete.
MR. BELL: I intend to. Eileen always does an excellent job
we think in describing a situation on this issue and the status, and at
times representing the dialogue that's been going on.
Now my simple message is that we believe we've come to a
common understanding in particular on the last two significant remaining
items, which are, as Eileen was talking about, criteria 7 and 8, 7 being
the replacement for the margin-of-safety criterion, 8 being an entirely
new criterion, which has given us some pause, and staff has paused with
us to really try and roll up our sleeves and anticipate the implications
as best we can.
We've sent a letter last Friday, and I think it's in your
package. It's an April 30 -- you may not have had time to absorb it.
Basically there's a lot of agreement reflected in there, as I'm saying.
In addition, though, we just sort of underscored the need particularly
with the brand new criterion on methodology that there needs to be
guidance that goes along with the guidance -- the devil's in the
details, as you know, the guidance will be essential in helping people
implement the new criteria. We propose --
DR. POWERS: I guess I'm surprised that you haven't asked
for more flexibility in that criterion 8.
MR. BELL: You're surprised?
DR. POWERS: Yes. I mean, it has -- it doesn't seem to
match with the language that goes more than a minimal change elsewhere.
It seems to be much more restrictive. I'm surprised.
MR. BELL: I think it is more restrictive, and it concerned
me certainly initially that there did appear to be for lack of a better
term a double standard for a certain type of change versus other types
of changes you could make under this rule.
We think that while the standard may be different in terms
of acceptable changes without prior NRC approval, I guess we pulled the
string on this enough and discussed it with the staff and convinced
ourselves that there will be sufficient flexibility to not, you know,
handcuff licensees.
A lot will have to do with the guidance that goes along with
well, what's essentially the same, okay, if a change moves a result in a
nonconservative direction. And what is a departure, that's part of the
question, what is a departure. It's what I mean when I say the guidance
on implementing those words will be very important. So --
DR. MILLER: That's the guidance -- I'm on page 7 of the
letter.
MR. BELL: Yes.
DR. MILLER: You describe the guidance there that you
recommend. Has there been agreement on that guidance?
MR. BELL: It may be my page 5. Is that the three bullets?
DR. MILLER: It starts on page 5.
MR. BELL: The following shall not be considered a
departure.
DR. MILLER: That's page 7 in the letter I have.
MR. BELL: Right. We have discussed those points with the
staff. I'll not characterize their position on them, but we think these
reflect some discussions we've had with them, the heads nod, we think
that this type of -- we intend to put this type of guidance in our
revision to 96-07. I think it says here we think it would be very
valuable to put it right in the statements of consideration.
DR. BARTON: Yes, and it's not in there, but then you said
you were going to put it in your guidance anyhow.
MR. BELL: Yes. Yes. And of course we'll need to work with
the staff on the guidance and drive that to --
DR. POWERS: In another context, the institution you
represent has worried when the interpretation of rules depends on
personalities, and the creeping of regulation. That doesn't bother you
here?
MR. BELL: I think we've struck the best balance we can, to
give you a political answer.
I think so. I think so. We've got a lot of experience,
both we and the NRC in dealing with these kinds of things. These are
not new kinds of things. In fact, licensees have been controlling
methods under 50.59 for years, because that's been part of NSAC 125
guidance.
DR. POWERS: And it's worked well, so --
MR. BELL: We think so. We don't think there's really
anything broken here, and so the subject of licensee burden came up,
whose burden is it, you know, in particular on this one, and I think it
was you, Dr. Powers, said it's the licensee's burden clearly. It's a
50.59 is their rule to implement, and that's why we think it will be so
important that there will be clear guidance on this.
I think the licensees are pretty confident. They know when
a new or modified methodology is appropriate to use in a particular
application. I think they are very good and adept and experienced at
that. But we would not want a new regulatory criterion to come up and
now there would be, you know, we want there to be confidence as well for
licensees to understand when a change in a method of evaluation requires
prior NRC approval. They know what's appropriate from an engineering
technical sense, and we will need the rule and the guidance to be very
clear to help them make sure that they --
DR. POWERS: There clearly is a point where the skills of
the art have to come into play and you just have to acknowledge that,
and I guess what you're saying is that the skills of the art of
engineering, 50.59 evaluations are such that you can live with this
language.
MR. BELL: We think so. We'll work hard on the guidance. I
think examples will be very important. We'll try and choose examples
that typify the most commonly done kinds of analyses and the kinds of
analyses that are most likely to change, and again drive those examples
to agreement with the NRC and get ultimately their endorsement on the
guidance.
DR. POWERS: I personally would appreciate any chance you
have to share with us the examples you're looking at. I think it would
be enlightening for all of us.
MR. BELL: We can certainly talk about getting on the agenda
in the future. Our plan is to revise this -- our guidance document over
the summer. When we have a product ready for prime time, we'll share it
with the industry for wide review for NRC probably for information at
that point. At some point we'll of course send it over for endorsement.
And again when it's ready for that kind of a -- at that point we'll
share it with the Committee as well.
The only other thing I was going to say in my prepared
remarks is the point about the implementation period, 6 months, 18
months, 12 months, as we recommended in our letter of Friday, we think
it's appropriate to tie the implementation -- the effective date of the
rule to the day -- to a period after you've got approved guidance or
endorsed guidance.
Licensees cannot go on and adjust their programs, processes,
and procedures, retrain all their people, unless they have the
confidence they know what to train on, and what to change their
procedures to. So they absolutely have to have that. And our sense is
from a poll of our task forces that they need about six months after
they have that confidence.
So in any scheme that the staff proposes on implementation,
I would like to see -- we would like to see some kind of an interim
milestone at which point there would be at least staff approval or staff
recommendation to publish the NEI 96.07 for public comment similar to
the process that's been going on now in the FSAR area.
DR. WALLIS: Can I ask you about this 10 percent of margin
business?
MR. BELL: You bet.
DR. WALLIS: When you wish to make a change and some
engineer has to decide how to approach the NRC or whether or not, is
your expectation that this person is going to make some assessment and
say oh, this is a 1-percent change of margin, therefore I don't need
to -- that requires making the calculation that leads to that 1-percent
figure?
MR. BELL: There is a point of clarification that's needed,
and it happens to us all the time, but we mix our terminology. When we
say 10 percent, whenever we're talking about 10 percent, the only place
that comes up in the proposed rule is in the area of consequences. Ten
percent increase in --
DR. WALLIS: Everything you do has consequences.
MR. BELL: Dose, consequences as under the criterion.
DR. WALLIS: So how do you decide when you have to actually
make this calculation about percentage of margin you're eroding?
MR. BELL: In the area of margin, we've avoided the notion
of margin.
DR. WALLIS: No, but this is the definition of minimal, is
it's 10 percent of the available margin.
MR. BELL: And in the new criterion on fission product
barrier integrity, I won't say margin of safety, because it's not a
margin-of-safety criterion anymore, it's criterion 7 on fission product
barrier integrity, the term "minimal" doesn't appear, 10 percent, the
term "margin" doesn't appear.
What we really wanted to make the criterion very objective,
very implementable, is an objective criterion, an objective limit, and
we selected design basis limits for those fission product barriers.
Those are hard, fast numbers.
DR. WALLIS: There are all these minimal increase in, there
are three of these --
MR. BELL: Um-hum.
DR. WALLIS: And we learned -- I thought I learned that
minimal means less than 10 percent margin. And that would seem to imply
that every time you contemplate doing anything, someone has to say are
we or not going to violate this minimal increase requirement. Doesn't
that require doing the same kind of assessment that we're trying to
avoid having you to do?
MR. BELL: I think you're reading from something that I
don't have the benefit of, but again there's I guess a total of eight
criteria coming. The minimal increase in likelihood or frequency --
DR. WALLIS: Likelihood of occurrence of malfunction of an
SSC. Minimal increase in consequences of an accident previously
evaluated. Minimal increase in consequence of a malfunction of SSC.
Now --
MR. BELL: What we need to do is divorce -- those
are distinct --
DR. WALLIS: Make an assessment of is it minimal or not.
MR. BELL: Right.
DR. WALLIS: It's the same old problem we've had all along.
MR. BELL: Right.
DR. WALLIS: And we learned today that's 10 percent at the
margin. So doesn't someone have to make this assessment and when do
they have to calculate whether or not it's 1 percent, 2 percent, 3
percent?
MS. McKENNA: Perhaps I could step in for a moment here.
DR. WALLIS: Please.
MS. McKENNA: The 10 percent you're referring to -- arises
in guidance on how to implement the minimal increase in consequences,
and you're looking at 10 percent of the difference between where you are
and what the limit is that's established in the regulation. We're not
trying to view it -- we're not going to call it margin or whatever,
saying this is a way of judging minimal for consequences. That's the
only use of the 10 percent that we have.
DR. WALLIS: But that's what I'm saying, doesn't the
licensee have to always ask, "Don't I have to calculate that?"
MS. McKENNA: That's part of their evaluation of what the
change they're doing, how does that change affect the facility and does
it have an effect on consequences, and if so --
DR. WALLIS: Why should they not have to calculate that for
every change, just as that was the problem we had all along?
MR. BELL: And in fact we do. This is an exercise I think
was very effective when we went through it with the staff. We had a
series of examples. The focus of the meeting was on the margin of
safety, the replacement criterion for the margin of safety. But what
was very effective is to take each example through all eight criteria of
50.59.
So you take a change, an aux feed water pump flow change.
Your as-found condition flow rate is less than what's written in the
SAR. Okay. So criterion 1 is does that cause an increase in the
frequency of an accident. Okay. And we answered in that case, and we
had our panel of experts, and discussed with the NRC. I think the
answer was no to that. We went to the next question.
DR. WALLIS: Minimal increase in the likelihood of
occurrence.
MR. BELL: Of a malfunction --
DR. WALLIS: Malfunction.
MR. BELL: In this case. Again --
DR. WALLIS: To safety.
MR. BELL: Again we came up with no on that, and we took --
DR. WALLIS: Well, suppose there is a change. You have to
assess it. Then eventually you're going to have to use the 10-percent
criterion.
DR. SHACK: Yes, he has to do the evaluation.
DR. WALLIS: So he has to evaluate --
DR. SHACK: He has to do the evaluation.
DR. WALLIS: So he has to do a PRA.
MS. McKENNA: No. No, I --
DR. WALLIS: Why not?
MS. McKENNA: They have to evaluate every change against
each criterion. Now the answer may be for particular changes, and for
instance this aux feed may be a case, that there is no change in
consequences. You don't have to try to quantify or to calculate it,
because you know, you understand the change you're making and how it
affects the plant.
By contrast, in some of the examples we have in the notice,
if you're changing something in the filtration system of your fuel
handling building, you may have to -- where you could be affecting
consequences, you're going to have to look at that and see whether that
change is going to be increasing the consequences more than minimally as
laid out in the criteria. So that does have -- all the criteria have to
be addressed, but the answer can be there is no change in consequences
because of what thing I'm doing.
DR. WALLIS: Yes, but if there's no change in consequences,
then that was never a problem anyway.
MS. McKENNA: Right.
DR. WALLIS: So we're only talking about when there is a
change in consequence. I'm just trying to establish if the amount of
work that has to be done has changed in any way by saying 10 percent.
You still have to make all the evaluation.
MR. BELL: That's right.
DR. WALLIS: Does the amount of work that's required in
order to allow the licensee to make a change change?
MR. BELL: No, I don't think so, but what has been improved
is that 10 percent is a very clear line.
DR. WALLIS: So there's no reduction in burden, there's
only --
MS. McKENNA: I would say characterize it this way. The
reduction in burden would arise from those circumstances where if you
looked at it and you said it needs the 10 percent, and therefore I do
not need to get NRC approval for this change.
DR. WALLIS: There is no reduction in burden in making the
calculation. There is in what you have to do afterwards.
MS. McKENNA: Correct. Right.
DR. BONACA: Yes. Because, I mean, what I'm trying to say
is that the USQ is a significant thing within the utility. Once you
have that, you have all kind of committees that now get involved in that
kind of review, et cetera.
DR. WALLIS: I was just trying to clarify.
DR. BONACA: It is --
DR. SEALE: And one other point. The number that's changing
was not born in a PRA. It was a licensing calculation, before George
ever thought of PRA.
DR. KRESS: And it will stay that way.
DR. SEALE: Yes. Exactly.
DR. WALLIS: You mean licensing calculations involved
likelihood?
DR. SEALE: No, they involve margin.
DR. WALLIS: But it says minimum increase in likelihood.
You've got to calculate --
MR. BELL: Of course back then the term was probability.
DR. WALLIS: You've got to calculate the increase in
likelihood. Can you do that?
DR. APOSTOLAKIS: That was the problem all along.
DR. WALLIS: That's what the problem still is, isn't it?
DR. APOSTOLAKIS: And it still is.
DR. WALLIS: Right. Okay, it still is the problem.
DR. APOSTOLAKIS: But we will risk-inform it, so --
DR. KRESS: Suppose your change in consequences ended up
being 10.3 percent. Is that the same thing as 10 percent?
MR. BELL: That's a good question. I think in the guidance
I think they've used the term in the ballpark or in the range of 10
percent, and I think the guidance we might agree on with the staff is
that, you know, round it off, you know --
MR. MATTHEWS: That's the reason we didn't want to put it in
a regulation.
DR. KRESS: Is 11 percent probably the same thing as 10
percent?
DR. WALLIS: Let me ask you, is calculating the likelihood
of occurrence less burden to you than calculating the probability of
occurrence?
MR. BELL: No, George tells me it's exactly the same.
DR. WALLIS: So it's exactly the same.
DR. POWERS: To be precise.
MR. BELL: Recognize that the assessment of whether your
likelihood of a malfunction is increased could be a qualitative one, as
it is today, and the rule does not require you to now go off and
perform, you know, a probabilistic analysis to get first a baseline
number, then an after-the-fact number, compare the two, it does not
require that.
In fact, the subject of the term "negligible" came up
earlier. The NEI guidance we don't expect this part of the guidance to
change because licensees have become accustomed and are quite used to
the "negligible" standard in terms of qualitatively assessing an
increase, whether there's an increase in the probability of an accident
or malfunction.
So as the committee heard before, there has been a
stipulation that negligible is always less than minimal.
DR. WALLIS: No, but I say we believe that negligible is
fine, but now you are allowed minimal you will probably take minimal.
MR. BELL: The flexibility is there and we support the term
"minimal" in the rule and we think that given more experience with
risk-informed methods and techniques that over time utilities will be
able to make better use of the additional flexibility afforded by the
minimal standard.
I think we expect the rule in the SOC to build a room on the
back of the house for that purpose, that we can furnish later on.
DR. WALLIS: But how soon will it be before the margin is
eaten up? Presumably there are some projections about how utilities
will respond to this rule. They will probably take advantage of it.
At what rate will they eat up margin do you anticipate?
MR. BELL: Well, you know, again it is really a bridge we
haven't crossed. We built that room on the back of the house and we
will add pieces to it as we --
DR. WALLIS: We are making a change in the rule without
having the awareness of the likely consequences.
MR. BELL: The other problem is that there is really no
limit or singular acceptable number for accident frequency, okay, so in
terms of eating up the margin, it is a difficult calculation.
DR. WALLIS: It would seem to me that one should when making
a rule anticipate what the consequences will be, and if the consequences
will be for a utility to come in the next year with a whole lot of
changes which eat up all the margin, then we will be back where we were
before this rule was promulgated.
MR. BELL: Well, we have committed to work with the Staff
based on what they are prepared to put in there --
DR. WALLIS: That's fine, but you don't have an awareness of
the likely consequences of the rule, except that people will feel
happier.
MR. BELL: In this area there is room for building on in the
future so -- they have been making minimal changes for 30 years.
DR. BONACA: One comment I have is this is really, what you
have here is what has happened for the past 40 years, except for the
last three.
MR. BELL: That's right.
DR. BONACA: I mean literally what this does, it formalizes
what has taken place and it hasn't been quick as far as I can see, so
hopefully just because you codify it --
DR. APOSTOLAKIS: What we should do then is publish this and
probably something else that says keep doing what you were doing --
don't interpret this new rule in any different way.
[Laughter.]
DR. APOSTOLAKIS: Is that the meaning of what we are saying?
MR. BELL: That's part of my message to a number of
audience --
DR. APOSTOLAKIS: Please don't interpret the 10 percent in
any different way, just keep doing what you were doing the past 30
years.
DR. POWERS: Well, I think that is 9607 or --
DR. WALLIS: Well, I don't understand it. If I were a
utility and I saw I could take 10 percent I would want to take it and
then I would want to take another 10 percent if I could take that. I
wouldn't be restrained by what I had been doing in the past years.
DR. POWERS: I think that it is also fair to say that at
least in my experience engineers doing a 50.59 evaluation of anything
have been far more conservative than I would have been. I think as a
general rule they do not push the envelope on that -- as a general rule.
Is that your experience?
MR. BELL: Absolutely. It's a conservative group.
DR. POWERS: I think we need to move along, just because we
have another presentation.
MR. BELL: Yes, you do.
I thank you very much and I'll take you up on the idea to
come back and talk to you when the guidance ripens. We have some
examples that we think could be extremely useful.
DR. POWERS: Thank you alot. At this point I will turn to
you, Dr. Fontana.
DR. FONTANA: The next topic we have here is on license
renewal and the purpose of the session is to hear presentations by
representatives of the NRC and Baltimore Gas & Electric Company
concerning the Staff safety evaluation report related to the Calvert
Cliffs license renewal application.
We held a subcommittee meeting with the Staff and BG&E on
April 28th and 29th, 1999, and in this presentation to the full
committee we intend to cover ground rules for license renewal, the
overview of the BG&E Calvert Cliffs license renewal application, and a
summary of the safety evaluation report.
We expect to issue an interim letter after the meeting. At
the end of the session we would like to discuss what the contents of
this letter might be.
The presentation will start with Mr. Chris Grimes, Chief of
the License Renewal and Standardization Branch, and Chris --
MR. GRIMES: Thank you, Dr. Fontana.
As Dr. Fontana mentioned, last week we briefed the
subcommittee in some detail on the Staff's review of the Calvert Cliffs
license renewal application and the content of the safety evaluation
report and for this afternoon's briefing we are going to present a
summary of the contents of Part 54. BG&E is going to make a
presentation on how they prepared their application for the Calvert
Cliffs plant, and then we will present a summary of the Staff's safety
evaluation.
The Project Manager for the Calvert Cliffs license renewal
application, David Solorio, is not with us today. I gave him a break.
I told him to take some time off.
DR. POWERS: He's getting old fast, huh?
[Laughter.]
MR. GRIMES: It's been a pretty aggressive review schedule.
The Part 54 presentation will be made by Steve Hoffman, who is a Senior
Project Manager in our organization and we will entertain any questions
about the Part 54 aspect of it.
We did not intend no going into the Part 51, environmental
impact, aspects but we'll respond to any questions you have in that
arena if you so desire, then BG&E will make their presentation and then
finally Dr. Sam Lee will present the safety evaluation contents, and we
have various members of the technical review staff who contributed to
that safety evaluation with us, and I am also assisted ably by Dick
Westman, who is the Deputy Direct in the Division of Engineering, and
hopefully we will be able to address any questions that you have about
the scope and conduct of this first license renewal review.
Unless there are any general questions, Steve?
MR. HOFFMAN: My understanding is that you guys would like a
quick overview of the license renewal rule and more or less what the
Staff is reviewing the application to. I will try and go through it
quickly. If you have any questions, want more depth, let me know.
The Atomic Energy Act obviously licensed plants to operate
for 40 years and allowed for renewals and puts no limit on the number of
renewals that can be requested.
Part 54 was issued to provide the technical and
administrative requirements for a safety review. Part 51 was revised to
provide the environmental requirements for renewal. Part 54 provides
for a new license that will be issued. It will supersede the existing
license. It will be granted for whatever remaining term is left on the
Part 50 license plus up to 20 years extension for the extended period of
operation.
An application can't be submitted earlier than 20 years
prior to expiration of the current license and must be submitted at
least five years prior to expiration if you want the timely renewal
provision to apply such that they can continue to operate if for some
reason the Staff hasn't finished its review, and the rule does require,
as you are aware, the ACRS review and report and also allows for public
participation.
The License Renewal Rule is based on two fundamental
principles, which they are actually included as slide 5. To help
understand it, we have kind of broken it down this way, because between
the two principles and significant determinations of the Commission,
these are pretty fundamental to the license renewal.
The first one is that the regulatory process is adequate.
It is the means by which the Commission continually assesses the
adequacy of and compliance of a plant with its current licensing basis,
ensures that an acceptable level of safety is maintained. The current
licensing basis is defined in Part 54 and it is through plant operation
through life. It does -- is continually changed and updated.
The Commission said that if an issue comes up that is
relevant to the current operation of the plant, it should be taken on
and addressed under the existing Part 50 license, using those processes,
and that it is not subject to carryover and review for renewal.
DR. KRESS: On that first bullet, do you have a definition
in mind of what ensuring safety means?
MR. HOFFMAN: The current licensing basis will be
maintained. Renewal is ensuring, you know, that --
DR. KRESS: So that means the regulatory process is adequate
to ensure that the current licensing basis is maintained?
MR. HOFFMAN: And that it will continue.
DR. KRESS: And that that -- and you equate that with
ensuring safety?
MR. HOFFMAN: Well, and will continue to maintain safety.
DR. KRESS: Continue to maintain.
MR. HOFFMAN: As new issues are raised, the Commission will
take whatever action is necessary. Through the years, you know, the TMI
action plan items, that is the regulatory process working. You know, if
something is identified, it will be, you know, imposed.
DR. WALLIS: That is an assertion really.
MR. HOFFMAN: That is a principle of licensing.
DR. WALLIS: Whatever you do is sort of an assertion.
That's fine. It doesn't require that you check by defining all the time
safety and then reevaluating the process. You are saying the process is
adequate and we will use it.
MR. HOFFMAN: Right, that is the principle of the rule.
Concerning the current licensing basis, the Commission
determined that you didn't need to compile it. License renewal is not a
re-review, it is not a verification of compliance with the current
licensing basis. License applicants are not required to meet latest
standards, they have to continue to show compliance with their current
licensing basis.
However, license renewal is in addition to. The current
licensing basis carries forward, it has to be maintained in the same
manner, to the same extent as it currently is. And so in a way, Part 54
is an addition to the existing requirements.
License renewal is focused on passive, long-lived components
and time-limited aging analyses, which in the following slides I will
explain that more thoroughly. And it is focused on managing the effects
of aging during the period of extended operation. We are looking at the
extended period, not the current operating license.
DR. WALLIS: It should focus on what has changed,
presumably, that should be the guidance. Is it that the long-lived
structures have changed and that their ability to crack and so on may
have changed over the years? That is what you are -- you are focusing
what has changed, on what has changed.
MR. HOFFMAN: We are focusing on ensuring that the licensing
basis they have now, the requirements that they need to meet will
continue to be maintained in that extended period.
DR. WALLIS: That's right. So things like thermal dynamics
haven't changed over the years, but the nature of the structures has
changed by radiation and so on, isn't that what you mean?
MR. HOFFMAN: That would be evaluated. Look at the effects
of aging on the structures and components.
DR. WALLIS: Right. So I am asking the question, so what
other things might have changed? And one thing that it seems has
changed is people. The way human beings respond today isn't the way
they responded when the rules were written 40 years ago. So you might
have to consider the human changes.
MR. HOFFMAN: We aren't looking at human changes. If there
are changes in procedures, fitness for duty, that is all written into
the procedures and that is part of their current licensing basis.
DR. WALLIS: I think, fortunately, the human factor has
improved, but you couldn't assume that a priori, you would have to
probably assess it. But if you can assure us that the human factor is
part of the equation that has got better over the years, and there is no
question about license renewal, but if the general responsibility of
people in society deteriorated over a generation, then this would be
grounds for concern.
MR. GRIMES: I think if Steve could continue with an
explanation of the content of the rule, there is a defined scope of the
facility that we review to assess whether or not there are adequate
programs for managing particular aging effects.
DR. WALLIS: You are looking at regulations. I am just
trying to look at the overall picture. That it seems to me when you
renew a license, you should ask what has changed. I mean if nothing has
changed, then it is just as good as it was before.
MR. GRIMES: The rule was constructed in way to look at --
that changes associated with aging effects on a facility. There are
aspects like -- other things that are expected to change, associated
with the current licensing basis, for which the rule presumes that the
regulatory process will continue to make appropriate adjustments for
things like staff training, operator licensing, emergency planning. And
those are things that are not within the scope of this particular rule.
DR. KRESS: Suppose a plant is built in a location where the
close-in population increases from the time it was licensed up to the
time -- thinking about relicensing it, by a factor of three. Is that
still a safe plant, or is that a consideration in your -- what you are
doing?
MR. HOFFMAN: We do not look at the siting criteria in order
to determine whether or not this is still a suitable site. That part of
the current licensing basis carries forward. You might reach a point
where you would say that you can no longer provide reasonable assurance
the emergency plan will achieve its appropriate protection of public
health and safety. But, otherwise, we did not consider siting criteria
to reassess whether or not license renewal should be granted.
DR. FONTANA: Does the generic EIS cover some of that?
MR. HOFFMAN: The generic EIS does cover some of those
considerations in terms of what are the appropriate changes associated
with the environmental impacts.
DR. FONTANA: Okay. All right.
MR. HOFFMAN: Getting into what the world defines as the
scope, you have three criteria. The first one is safety-related. That
is the standard definition you have used before for that.
The second one, non-safety-related systems, structures and
components whose failure could affect the functionality of the
safety-related components. The applicant is required to look at
failures that are part of their current licensing basis. They don't
have to look at hypothetical failures that are not part of their
licensing basis. But if their licensing basis goes down to second,
third, fourth level, they need to evaluate that.
And the last criterion is the systems, structures and
components relied upon for compliance with those five regulations.
DR. APOSTOLAKIS: So does this mean then that PRA
calculations are excluded because you go beyond design basis there?
MR. HOFFMAN: The Commission looked at use of risk analysis
when it was developing the rule, and it said that -- its evaluation was
that the current licensing basis is founded primarily on deterministic
engineering criteria, and so they decided that the scoping criteria
should be deterministic and not use a plant-specific PRA. But it went
on to say risk insights could be used in determining the relative
importance of structures and components, subject to review, in
determining the programs needed to manage it, so. And then risk
insights were always being used in developing our inspection programs
when the teams go out. Okay.
Now, we will go to the contents of an application. The rule
requires the licensee to perform an integrated plant assessment. And
what that is -- now, let me back up one thing. The integrated plant
assessment. We started out at the systems structure, the big, the large
structure level and now the integrated plant assessment is going down to
the component level.
The structural subcomponent level -- aging management is at
the component level. Now out of the systems, structures and components,
we are in scope. What we do now is what is called screening to identify
the structures and components subject to review.
The IPA is that assessment by the licensee that the effects
of aging on functionality of structures and components will be managed
for the period of extended operation.
The first thing that is required in the application is for
the licensee to identify and list the structures and components subject
to an aging management review and those are defined as those that
perform their intended function without moving parts, changing
configuration or properties -- what we call passive.
DR. WALLIS: Is that equivocal or not? Do you have
something which when you load it moves, like a piece of pipe or
something? That I think is a passive component.
MR. HOFFMAN: That's passive.
DR. WALLIS: And something which does or does not carry
electrons which are moving is passive and so --
MR. HOFFMAN: Right.
DR. WALLIS: -- this is something which is not subject to
misunderstanding.
DR. SEALE: He's got a list there.
DR. WALLIS: I am sure you know what they are.
MR. HOFFMAN: The second criterion it has to meet is it is
not subject to replacement based on qualified life or specified time
period. In other words, it is short-lived. That replacement interval
should be determined based on its useful life and it will be replaced
before aging effects will have affected its functionality.
Now the active the Commission determined could be
generically excluded because they have determined that the degradation
of active components is more readily apparent. It will be picked up
through performance condition monitoring that is ongoing and therefore
they determined that they could credit existing programs and in
particular the maintenance rule program for managing aging of the active
components.
The review is to ensure that the intended functions will be
maintained and those functions are as they describe up there, those
functions that the component must fulfill that forms the basis for
including within the scope.
DR. WALLIS: Really the first definition of passive would be
those components which are not already assured because of maintenance
and so on. It's anything that is not covered as an active component
automatically becomes a passive one.
MR. HOFFMAN: That is not the way we come in at the scoping
and screening. You want to look at the component itself and determine
if it performed its --
DR. WALLIS: And nothing falls between the cracks? I am
just worried you say that active components are already taken care of so
we only need to worry about the passive ones, and that means the passive
ones are essentially those which are not taken care of already by the
maintenance rule.
MR. BARTON: The maintenance rule takes care active --
MR. HOFFMAN: The maintenance rule --
DR. WALLIS: -- is your concern.
MR. HOFFMAN: Yes. The maintenance rule does not exclude
passive.
DR. WALLIS: Just want to be sure there is nothing in
between that doesn't get caught either way.
MR. GRIMES: Dr. Wallis, I would like to point out that we
have done a very close comparison of the maintenance rule against
license renewal and we think that they are complementary, but I would
point out that the maintenance rule puts an emphasis on risk insights in
terms of identifying what the importance is.
License renewal tries to keep the deterministic approach so
that there is a consistency across the licensing basis and the
programmatic aspects of how the plant is maintained. I just want to
make sure that there is not a misimpression there. It isn't a perfect
fit, but there's a sufficient amount of overlap and distinction that we
are comfortable that the maintenance rule and license renewal are
complementary.
DR. WALLIS: Thank you.
MR. HOFFMAN: The next two slides actually list structures
and components that the Commission actually included in the rule as to
what is considered to be passive and active. Unless you have any
questions I won't bother to go into that.
DR. KRESS: Is this an inclusive list?
MR. HOFFMAN: No. That was just examples the Commission
wanted included to explain what was intended.
DR. POWERS: Isn't the language -- the language I think is
explicit on that.
MR. HOFFMAN: Yes.
DR. POWERS: It includes but not limited to.
MR. HOFFMAN: Yes. Yes. Now that you have your list of
structures and components subject to review, what the application then
must include is a description of the methodology that was used to
identify those structures and components and then the big part is the
demonstration that the effects of aging will be managed such that the
intended functions will be maintained consistent with the current
licensing basis for the period of extended operation.
We are trying to ensure functionality in accordance with the
current licensing basis for the period of extended operation.
In addition to your integrated plant assessment, the rule
also requires evaluation of time limited aging analyses -- TLAAs. To be
a TLAA -- okay, the integrated plant assessment was at the structure and
component level. The Commission believed that TLAAs could be at the
system level so TLAAs could involve systems as well as structures and
components and also could involved active as well as passive, and to be
a TLAA it has to meet all six of these criteria, the important ones
being obviously that the systems, structures and components are within
scope, involve the effects of aging, and the key one is that it involves
time-limited assumptions based on the current operating term of 40
years.
Once you have identified those --
DR. SEALE: You say they involve systems and structures and
components that have been identified, but that is not all structures,
systems and components in that system, is it? Your first bullet.
MR. HOFFMAN: Within the scope of the rule?
DR. SEALE: Yes.
MR. HOFFMAN: That gets back to the safety-related,
nonsafety-related requirements --
DR. SEALE: -- the time limiting aging analysis -- parts of
the system that is involved might not be -- do you see what I am saying?
MR. HOFFMAN: Within the scope?
DR. SEALE: Yes.
MR. HOFFMAN: Actually, when you do your scoping, that
initial scoping, you may bring a whole system in and the only reason it
is in is maybe because it's got a penetration in containment, so then
when you go back and do the screening it is only the penetration from
that system that is subject to review.
DR. SEALE: But then it might, the system might get a
time-limited aging analysis as a system, not as a penetration?
MR. HOFFMAN: Correct.
DR. SEALE: Okay.
DR. APOSTOLAKIS: So what is the difference between or the
relationship between the aging management review and the time-limited
aging analysis?
MR. HOFFMAN: What happens is that the way you evaluate and
assess them, okay? What you do is for the period of extended operation,
the applicant has three options. In some cases the analysis already may
have gone out to 60 years or greater so they don't need to do anything.
In other cases they may be able to go back, re-analyze and extend the
analysis out to 60 years or they can choose to manage the effects of
aging which in essence puts it back into the same approach you used for
the integrated plant assessment.
DR. POWERS: I think that it is easy to get lost in the
abstractions here. An example is useful.
For instance, in the original analysis someone, as I
understand it, someone may have said okay, over 40 years this much
corrosion could occur on this item.
He has put a time limit on his analysis that now has to be
revisited to make sure that analysis is still valid now for 60 years.
DR. APOSTOLAKIS: And that is under TLAA.
DR. POWERS: And that is a TLAA.
DR. SHACK: The TLAA would be the aging processes that you
anticipated during the design and you allowed for for a specific period.
Aging management will cover all the other aging processes that you
didn't think about during the design.
DR. POWERS: The abstractions sometimes get a little
confusing here and a few examples make it clear.
DR. SHACK: I mean for example you knew that some components
were going to be subject to thermal cycling so you designed them with a
fatigue life that was long enough to last the 40 years. You didn't
expect them to be stress corrosion cracking, and so you didn't have a
time-limited aging analysis for that but you certainly have to have an
aging management program to manage stress corrosion cracking.
MR. HOFFMAN: Okay.
DR. SEALE: Now you start to spend real money.
MR. HOFFMAN: Okay. A subset of your TLAAs are an exemption
that may have been granted in accordance with 10 CFR 50.12 that may
still be in effect during the period of extended operation. If that is
the case you need to list and justify its continuation for the extended
period of operation.
So far the two first applicants have not identified any
exemptions that would meet this criteria.
In addition to the IPA and the evaluation of time-limited aging
analyses, the application is also required to include an FSAR supplement
that provides a summary description of the programs and activities that
manage aging as well as evaluation of time-limited aging analyses. This
is the method by which once the license is issued, it then changes to
the process or control in accordance with 50.59.
Additionally if there's any tech spec changes, the
applicant's supposed to include those as well as the justification for
the change. That's no different than today's requirements for a tech
spec change. And then the application should also contain an
environmental report in accordance with 10 CFR 51.
DR. APOSTOLAKIS: Let me come back to Dr. Shack's example.
We're not talking about the original license, we are talking about the
current license.
MR. HOFFMAN: Correct.
DR. APOSTOLAKIS: So originally you didn't think of
intergranular stress corrosion cracking, but now you have an augmented
program.
MR. HOFFMAN: Right.
DR. APOSTOLAKIS: So what do I do now? I mean, do I say --
DR. SHACK: The question is whether that program is good
enough to last for 40 years or for 60 years, and you have to
demonstrate --
DR. APOSTOLAKIS: But the program I have now specifies that
it's good enough for 40 years, or it doesn't say anything about time?
DR. SHACK: It doesn't say anything about time.
DR. APOSTOLAKIS: So why then do I have to revisit it? If
it's good enough now, it's good enough in 20 years.
MR. HOFFMAN: An applicant is required to look at operating
experience, both their own and other relevant industry experience, as
well as -- and industry. And if an aging effect has been identified
that is credible for their plant, okay, you need to ensure that either
it's not occurring, in some cases where it's possible but not certain,
they'll do an inspection. If it's something that is ongoing, they will
have a program that maybe will continue to inspect for it. If they've
got more experience with it, they may have a program that's managing it.
DR. APOSTOLAKIS: So in the AMR then I can come back and say
yes, flow accelerated corrosion can occur, IGSCC and the rest can
occur --
MR. HOFFMAN: Um-hum.
DR. APOSTOLAKIS: But I have already programs in place. I
have managed it. Thank you. What else do I need to do?
MR. HOFFMAN: Okay.
DR. APOSTOLAKIS: I mean, this is my current licensing
basis.
MR. HOFFMAN: Okay. We've seen approximately 80 to 90
percent of the aging-management programs that are current existing
programs.
DR. APOSTOLAKIS: Oh, okay. So what I'm saying is
happening.
MR. HOFFMAN: Another 5 to 10 percent are modified programs,
and maybe 5 to 10 percent new.
DR. APOSTOLAKIS: Okay. Good.
MR. GRIMES: BG&E is going to cover some of that in their
presentation when they talk about what has changed, but, you know,
Steve's point here is that to the extent that anything does change, if
they change the scope of surveillance, if they introduce a new kind of
maintenance program to address a particular aging effect, that that now
will be rolled into the licensing basis in the FSAR and the technical
specifications and the environmental impact will be updated.
MR. HOFFMAN: You see, the Commission when it excluded
active said, you know, it's not that there aren't existing programs for
passive long-lived components, they just -- they didn't have the
assurance for the group as a whole that existing programs existed, were
in effect to manage aging for passive long-lived, and so that's why
we're looking at those programs. And the Commission said, you know,
once we gain more experience, we may come back and further narrow that
review. But they needed to go out and look the first time, you know,
get that experience before they could narrow it.
DR. APOSTOLAKIS: That was part of defense in depth, you
think?
MR. HOFFMAN: Well, it was more the generic determination at
the time the rule was written that we couldn't generically state that
all passive long-lived structures and components had programs in place.
MR. GRIMES: I think I'd like to also point out that we also
have a recognition that plants have evolved and they now have programs
that differ, and so to the extent that there is now an issue that's
going forward to the Commission in terms of how to give credit for
existing programs, we are going to try to more directly confront the
nature of the staff's review in terms of where should we be turning our
attention to achieve appropriate effectiveness and efficiency in the
review.
For these first two applications, we have essentially
reviewed all the programs. We've looked across all of the scope and all
of the programs that are accredited for aging management in order to
come to a complete determination to reach the conclusion that Steve is
about to describe.
MR. HOFFMAN: Okay. This is the finding that the staff has
to make in issuing the license. That actions have been or will be taken
such that the effects of aging will be managed to ensure functionality
of the systems, structures, and components, and that all TLEAs have been
evaluated, and that the current licensing basis -- there's reasonable
assurance that the current licensing basis will be maintained for the
period of extended operation.
In addition to that, you know, the environmental
requirements of Part 51 have to be met, as well as any hearing
activities be completed. And in Calvert Cliffs case there was a
petition for hearing. It was denied by the Atomic Safety Licensing
Board. The Commission affirmed that. However, that is under appeal
with the D.C. courts at the moment.
DR. WALLIS: It seems to me you're going to be in good shape
when you already have an understanding of aging and it's being managed,
some component. What I'm not sure is how active you're going to be in
discovering other effects of aging which also really ought to be
considered which aren't yet on the radar screen of the aging managers.
That there are other effects -- you have to search for other effects of
aging than the ones you already know about. And I'm not sure how you
assure that you find them all.
MR. HOFFMAN: We are -- both the applicant and the staff are
looking at experience.
DR. WALLIS: Right.
MR. HOFFMAN: Okay.
DR. WALLIS: I'm sure you will do it, but how do you assure
that you find enough of those?
MR. HOFFMAN: Okay. The other thing we rely on again is the
regulatory process. If a month from now we discover a new aging effect,
the Agency is going to take whatever action is necessary. It might be a
generic letter, a bulletin, if it's appropriate. And that will then
become part of the current licensing basis.
MR. GRIMES: And I'd also like to add that as BG&E goes
through and describes the review that they did, the scope of the review
is generally conservative with respect to what BG&E refers to as
plausible aging effects, what others refer to as applicable aging
effects, even if they have not yet been manifest on a particular system.
If it's possible that they might occur in the future, then provisions
are made for some kind of inspection or maintenance practice. And so to
that extent we have part of -- we have reasonable assurance that if
things become manifest in the future that we will find them.
DR. BONACA: I have a question. As a result of this
process, do we have any safety-related passive components that are not
under an aging review or any one of these particular reviews for which,
for example, there are no commitments to inspections?
MR. HOFFMAN: All passive safety-related components
generally are in scope.
DR. BONACA: Okay.
MR. HOFFMAN: The only exception might be, it came up in
discussion with the industry, is some applicants for their own purposes
may have included nonsafety with safety, they've upgraded them to safety
just for administrative purposes on site. In those cases those, you
know, they would be allowed to exclude.
DR. BONACA: During the subcommittee presentation we heard
about some disagreement between the staff and the applicant for
inclusion of the internals in some inspection program.
MR. HOFFMAN: Well, the reactor vessel internals are
definitely in scope.
DR. BONACA: But originally through the process, the
application of the applicant, through the process, did not identify
that. Is it true?
MR. GRIMES: Not that we're aware of.
MR. DOROSHUK: My name is Bart Doroshuk, and I'm the project
director for the Calvert Cliffs license renewal project.
There was a particular shroud bolt in the reactor vessel
internals structure that there was a particular aging effect, stress
corrosion cracking of these particular bolts that are basically inside
the internals themselves, and the discussion that is going on is whether
or not that particular aging effect is in fact something that we need to
manage. And if that is determined that we need to manage that aging
effect, then what are the options available to do such. And I believe
that was -- that is a subject of an open item, that it's undergoing
discussions, but the reactor vessel internals has always been in scope.
It centered around whether or not the belts actually
performed a function other than from a maintenance perspective of being
able to lift the reactor internals out of the assembly, out of the
reactor vessel.
MR. GRIMES: Dr. Bonaca, I would also like to clarify that
during Dr. Lee's presentation of the safety evaluation conclusions, we
are going to identify a number of areas where the applicant has proposed
a one time inspection to verify that there is no evidence of the need to
manage a particular aging effect.
We have looked across the whole scope of passive, long-lived
systems, structures, and components and the safety evaluation describes
our conclusions relative to how those aging effects are going to be
managed, or whether they need to be managed. So that will be part of
the back end of the staff's presentation.
DR. BONACA: Because that was really where I was going. I
mean there are 25 years of experience on this plant and there is some
proposal to just to do one time inspection and that should cover all the
remaining life of the plant. The question is, how do you identify a new
failure mechanism? Maybe you have a radiologic to address that.
MR. GRIMES: No, the safety evaluation went through those
proposed one time inspections and we have an open item associated with
-- we felt that there were some of those that should be periodic, and we
are going to continue to pursue that with Baltimore Gas & Electric.
DR. BONACA: Okay.
MR. GRIMES: But we tried to be very careful about making
decisions about whether or not we felt a one time inspection was
appropriate to dismiss the need for an aging -- to manage a particular
aging effect. That we still have the defense-in-depth if this, if the
aging effect becomes manifest in the future, the quality assurance
program can catch it, the NRC events assessment can catch it. We can
always come back later and discover that maybe the one time inspection,
you know, didn't work out. But we are comfortable that that will manage
itself.
DR. BONACA: Thank you.
DR. FONTANA: Any other questions? All right. Thank you.
The next presentation is by Mr. Bart Doroshuk from BG&E.
MR. DOROSHUK: Good afternoon, Mr. Chairman and members of
the ACRS. On behalf of Baltimore Gas & Electric, my name is Bart
Doroshuk, and I am the Project Director of the License Renewal Project
at Calvert Cliffs. I would like to extend our appreciation for the
opportunity to provide you our comments today.
The overall objective of my presentation is to provide the
ACRS with an overview of the integrated plant results, which means the
aging effects analysis, aging management review and programs, as well as
the time-limited aging analysis results for the plant, and to discuss
the process we went through to determine the results. And then I will
spend a small amount of time, if it is available, to discuss the
implementation status of the findings submitted in our application.
I would encourage the committee, feel free to interrupt me
and ask questions as we go. I think that is the ground rules we have
been observing.
I would like to just point out that Calvert Cliffs is a two
unit CE designed site built by Bechtel, and the Unit 1 plant went into
operation commercial, or got its OL in 1974, Unit 2 in 1976. It is
located about 60 miles southwest of Washington, D.C. Each unit is 2300
megawatts thermal with an output of 860 approximately electric.
The site, which is shown here, is a 2300 acre site, of which
the plant itself, the facility, occupies only about 10 percent of that
site. The rest is farmland and wooded areas and a wildlife habitat
maintained by BGE and was subject of the environmental report as part of
the license renewal application.
The overall goals for Calvert Cliffs, the number one goal is
nuclear safety. If that goal can't be achieved and maintained, license
renewal will not be pursued as the option of choice. That is the number
one goal we will have to make whether it be license renewal or not.
Another goal for the plant by BGE is to remain cost
competitive as we approach deregulation, and maintaining that careful
balance between the safety goals and the appropriate cost
competitiveness. Along with that is to mitigate the stranded assets, a
timely topic, and I guess the catchy phrase for the capital still on the
books, and establish a decommissioning fund by shutdown.
DR. WALLIS: Now, there is no balance between safety goals
and being competitive.
MR. DOROSHUK: That is correct, sir. You either are safe or
you are not operating.
DR. WALLIS: Right.
MR. DOROSHUK: Another goal is to continue to be an asset to
our customers and stockholders, as well as stakeholders in the Maryland
area. And in achieving all that, we also have to retain the ability to
invest wisely in the plant.
The approach that Calvert Cliffs has taken at the plant has
been a teaming approach. We have referred to it as a life cycle
management approach. It is, in our opinion, broader than the focus of
license renewal. It is an entire evaluation of the facility from top to
bottom, not just addressing the technical environment issues, but all of
the surrounding issues involving al the state, local, political, federal
issues that you would have to look at for running a facility.
The approach we have taken has been to establish an
engineering team. We did this in 1989. The staff of that team has been
approximately 25 full-time engineers for the last ten years, and that
has grown based on the amount of work we have done, we are doing in the
particular year, and at some points, I think in 1997, we were up over 45
people for the entire year, just for the life cycle group at the plant.
There have been other teams that we have established
throughout the company that have been coordinated by this group to
ensure all of the issues surrounding the life cycle of the plant. They
are being addressed appropriately. These integrated teams have been
there to evaluate the plant beyond the typical planning horizon. The
solutions and the recommendations that the teams have come up with,
depending upon the issue, have been used using decision analysis
techniques showing both long-term and short-term benefits.
DR. APOSTOLAKIS: Do you mean formal decision analysis?
MR. DOROSHUK: In some cases we have used formal decision
analysis, specifically when we looked at the facility as a whole. And
we modeled the plant from a qualitative standpoint and then we
quantitatively modeled in a cash flow model, various types of cash flow.
DR. APOSTOLAKIS: This is in your petition?
MR. DOROSHUK: No, this was not -- this would not be part of
the application itself. It is part of the internal work we did looking
at the entire life cycle of the plant. And those types of models range
from the standard discounted cash flow type of looks to trying to model
the market place using probabilistic techniques. And then trying to --
what we referred to as test the model giving various stressors in the
areas of concern, whether it be long-term shutdowns, plant failures as a
result of aging and other types of drivers that might change the
results.
DR. APOSTOLAKIS: Thank you.
MR. DOROSHUK: The recommendations and actions that came out
of all of our analysis over the last 10 years have been through an
integrated implementation and it is ongoing today. Our focus has been
to ensure that the customer, i.e., whether it be the plant engineer or
the maintenance engineer, or the inspector in the field, the end user
was part of the problem definition, part of the solution development,
because that end user will be the one who owns the findings 10 years
from now. And it gets to Mr. Wallis' discussion earlier on how do you
deal with the human factors issues and change.
We believe that we have a very knowledgeable team today and
a very knowledge plant. We think that we have a very good handle on the
recommendations and outputs and the findings, and the findings in the
SER, the knowledge of license renewal, the knowledge of plant aging.
Our focus it to make sure that the individuals running the plant in 2010
and 2012 have the basis and the reasons as well. So we feel that is a
very important part, however, it is not a part of the proper review, the
actual formal review of the application.
The status of our review was that the application was
completed in early '98 and then submitted to the NRC in April. There
was a series of reviews and docketing and then questions were issued by
the NRC in the fall. This is a very high level pass-through and which
we responded to by the end of 1998 both on the safety side and the
environmental side.
The regional inspections, which were three that were done it
two actual site visits encompassing three weeks, were conducted on the
scoping part of the review, of the application, to ensure that we had
implemented the scoping methodology and come to the results that we said
we came to and they verified that through their inspection process in
February and found that to have been an effective and acceptable
implementation of the scoping.
In April a two-week review of the aging management reviews
that were conducted as part of the application, that team again returned
and looked from the top to bottom, and this has been -- this was a very
extensive inspection, both on scoping and aging -- and concluded after
that inspection that we had effectively and in an acceptable manner
developed an aging management program for the renewal period and that
inspection report is yet to be issued but we believe those to be the
conclusions.
Those were important -- that was a very important set of
milestones. The draft supplemental and environmental impact statement
was issued in March and the SER was issued in March as well. There are
28 open items and 20 confirmatory items in the safety evaluation report
that BG&E and the NRC are continuing to work and discuss and to go to
closure on and those will be the subject of the second presentation --
third, I mean.
With respect to the overall process, this is a new process.
We believe that the Part 54 and Part 51 revision do work. We believe
that you can execute both rules and you can get to a set of results
which we believe that the finding in 54.29 can be drawn from. There are
areas for improvement but you expect that with a new process. It has
not been an easy one but we think that overall we have been making very
good progress.
Now shifting to the actual --
DR. POWERS: You titillate us with this --
MR. DOROSHUK: Excuse me, sir?
DR. POWERS: You titillate us with this "we think there are
areas of improvement" -- please don't dodge that bullet a little bit.
MR. DOROSHUK: I didn't mean to dodge it.
You discussed it during the last presentation, which is what
do you do with these programs that you do the components and you look at
the aging effects and you find, goodness, I have an EQ program that does
all of this -- how much effort should it take a licensee to explain that
to the NRC, who regulates the program? And that is a very classic
example of an existing program and we trounced all over that during this
first time through and the licensee -- we got nervous that they were
maybe wandering into the areas they shouldn't wander into and they were
probably concerned about the same thing -- would they have to do this
for every licensee?
So there was some concern with regard to that, but we did
conclude that in fact the EQ program is an acceptable aging management
program, so being first we are expected to run through some of these
ringers for a little longer time, but what about Plant Number 3, 4, 5 or
when you have eight plants in here at the same time? The industry wants
to ensure the process remains stable. The NRC wants to make sure they
can review them, so the existing program areas, when you see some of the
results, you are going to see that, yes, there is an area that is
fertile for efficiencies.
Some of the other areas I guess, I don't know -- that is
probably the big one, but I wasn't prepared to go down an entire list
and I guess that would be a good example.
MR. GRIMES: Clearly the NRC Staff agrees. As a matter of
fact, we want to get some efficiency and --
DR. POWERS: Well, I think that this issue of efficiency is
an issue that the Commission is extremely interested in and that at some
time we are going to have to discuss lessons learned here. I don't know
when that is.
MR. GRIMES: We will arrange to -- we can discuss that
separately after we get over, at least get through the first two renewal
applications, and I also -- we will be sharing with you our Commission
paper on credit for existing programs, which is another area, and we
have been sharing with the committee the results of what we refer to as
the generic renewal issues where we try and dispose of some of the
questions about how to treat particular aging effects.
It took us some time to develop a position on the treatment
of fuses for the scope of license renewal. That was difficult for us,
but now that we are over that we can move on. We can move forward and
we are not going to spend time worrying about that one.
Similarly we have gotten through some other areas where
there are questions about where is the component, what appropriate
component level, what are the appropriate aging effects, and we intend
that we would have a feedback mechanism to continue to roll those into
improvements to the standard review plan.
I think it would be appropriate probably next fall when we
hope to start nailing down some of the details in the license renewal
process to take it to a production level, and we probably want to bring
the guidance improvements in the standard review plan to the advisory
committee and the CRGR and see if we can't put some more stability into
the process for the future.
MR. DOROSHUK: What I will do now is I want to go over how
Baltimore Gas & Electric conducted the integrated plan assessment, and
what I've provided here is a very simple flow chart that illustrates a
very complex process and a very detailed process. The rule itself only
requires us to tell you or put in the application, if you will, what the
answer is.
It says give us a list of structures and components that are
subject to an aging-management review and describe the aging-management
programs that are going to manage the aging. However, we recognized
early on that this truncated story needed some expansion, and so what
was in the application itself is something developed between the NRC and
BGE, is what is the overall story. And we'll talk about that a little
bit.
But this process starts with the entire plant and all of the
systems and structures of the plant, and determines using the rule
criteria which systems and structures of the overall plant are within
the scope of license renewal, meets one of those requirements. It does
this by looking at what functions the system and structure perform
against the rule criteria. Then it determines what components
contribute to those intended functions.
So I'll go back and forth to this particular -- the next
slide, and what this tries to do is to show you that we started out in
the plant with 96 systems and 25 structures. That encompassed the
entire facility. The systems that had functions that met the rule
requirements, there were 59 of the 96 systems. And there were eight
structures of the 25 that met the requirements of the rule.
We then looked inside those systems and structures and took
those functions that caused them to be in scope and identified every
single component that contributed to that function, active or passive,
we didn't care. Then to determine the actual population of components
requiring the aging management review, we then took them through this
process that first asked were the components that contributed to the
intended functions, do they have a passive or active function? And if
they were active, they were not subject to an AMR review. They were
covered by the maintenance rule. They were excluded by the statements
of consideration.
Then looked at the remaining, those passive components both
of systems and structures and asked ourselves and determined whether
they were periodically replaced by a commitment in the licensing basis
so that that commitment would continue to carry forward. And if they
were, they became not subject, because they weren't going to be
installed for longer than 40 years, and that was the criteria.
Then we asked were there some parts of the plant or some
pieces of equipment that were excluded by the rule specifically, and
those were dropped out too, and that left us with the residual parts of
the plant that had to go into an aging-management review. And that's
the first part of the integrated -- first deliverable, if you will,
formal deliverable of the aging-management review. However, the rule
required us to describe this and just report those results.
Then we took the components and broke them into -- if you
take a look from a -- you've got a system level, then from a system
level you go to the components. Those components were the valves,
piping segments, cables, they were with some grouping capability that we
were able to group them in, all hand valves, all check valves in a
particular system, determine the aging effects that we're concerned
about, and looked at were they managed by existing activities or if they
weren't, were we able to modify the existing programs that were close
but not quite there, or did we have to develop a new program in its
entirety.
What you see in the application is we broke it down into
system chapters, so out of these 59 systems, they were included in 21
chapters. There were eight chapters that dealt with commodities, and
that would be like cables or electrical panels, things that were
system -- plantwide in every system but we felt that we'd just discuss
them once instead of every single chapter. We discussed in five
sections the eight structures. And in each one of these chapters you
see the breakdown of the components.
So that is a quick overview of how we got to the application
from the aging-management review using this process. I just want to
pause here to see if there's any process questions that the Committee
may want to explore.
All through here is where you use your operating experience,
your plant experience, your program reviews, we worked with all the
plant, like I said before, those integrated teams.
DR. WALLIS: There were 96 systems and 59 were scoped, and
then there were 21 chapters on them.
MR. DOROSHUK: Right.
DR. WALLIS: Does this mean that you dropped certain systems
at each stage?
MR. DOROSHUK: No, we combined some.
DR. WALLIS: Combined. Ah. But 96 got a 59 by what
process?
MR. DOROSHUK: The process which is the step 1, which is to
look at the system functions itself.
DR. WALLIS: Ah, okay.
MR. DOROSHUK: And the intended function to the system said
were these intended functions met the three categories of the rule, and
those three categories, are they safety-related or are they
non-safety-related, that whose failure could cause the safety-related
failure, and then you had the five regulated events of EQ. Notice
there's no active-passive division at this point. The active-passive
division doesn't come until you're actually at --
DR. WALLIS: 96 went into active-passive?
MR. DOROSHUK: We had -- yes, 96 of the systems were
reviewed --
DR. WALLIS: And then 59 came out of where in that diagram?
MR. DOROSHUK: It came right out of here.
DR. WALLIS: I'm just trying to relate it, 96 went in --
MR. DOROSHUK: Right here. Assess is within scope.
DR. WALLIS: And 59 came out of that box?
MR. DOROSHUK: 59 came out of this box, and then we took the
59 systems and then broke them down into components, all components that
contributed to these functions. And then we brought those function by
function, component by component, through here.
Whether it was active or passive, you took the feedwater
system and determined the feedwater system within scope for all sorts of
different reasons.
DR. WALLIS: Everything went through the whole process or
went through enough of the process before it was dropped out.
MR. DOROSHUK: That's right.
DR. WALLIS: Okay. That's all.
MR. DOROSHUK: Any other questions on the process?
Okay.
DR. FONTANA: Yes.
MR. DOROSHUK: Yes, sir.
DR. FONTANA: How long did that take?
MR. DOROSHUK: Several years. It's a very
manpower-intensive -- I've referred to it, you're really performing
surgery on your licensing basis from the hardware perspective and from
the licensing basis, and you're mapping every single component to its --
DR. POWERS: You know your licensing basis better than
anybody else --
MR. DOROSHUK: We know it now. If you didn't know it before
you started, you know it now. And the reason it took us several years
is because in the middle of it the rule changed and we were originally
scoping when the rule required us to include all active and passive, and
so we were taking actually the first seven systems had gone through this
process without any active or passive screening.
So -- which actually was a benefit to us in the industry,
because what it did allow us to show when the rule was being considered
changed in 1993 and 1994, because that was when we were considering is
active an important part, when we took those seven systems through, we
had like an 8,000 components as a sample population, and we looked at
the active components and determined actually with the plant maintenance
procedures that over 95 percent of those active components, whether or
not they were in the maintenance rule now, were being replaced before
the 40-year period. And they had a history of replacement. So that
actually fell into giving the industry confidence that that active
exclusion was reasonably sound. So it wasn't for nought. We got the
pleasure of doing it that way, though.
It's a lot of paper, but it ended up being a lot of value.
The application itself sits on top of a significant amount
of information as we've kind of been dancing around. What you see here
is just an illustration, and this is the best way we try to visualize it
in our mind's eye, the application sits on top of the aging management
reviews for each system and structure. Inside those aging management
reviews are either the direct results or references throughout the
entire -- this pyramid, and I just walked through it.
You see the active-passive screening, the actual broad
scoping of the plant, which is based on the licensing basis of the
plant, the Q-List, the safety analysis, drawings, procedures, tests,
inspections, the NRC documents.
When you get into the aging-management review, you start
digging into the plant experience and to external documents and to all
the way down to textbooks. And so what this document that was reviewed
by the staff incorporates is a significant amount of references. And in
fact almost every sentence in the application has a direct reference to
something in this pyramid, and you can trace it back to whatever our
conclusion was.
And I'd like to at least acknowledge at this point, this is
what that regional inspection did when after the headquarters staff
gets, at least this is the way we see it, gets through reviewing the
process and the results, the region comes out and pulls a thread all the
way down to every one of these things, and it's quite a thorough
evaluation.
The goals of the aging management review are to demonstrate
that the effects of aging of structures and components within the scope
of license renewal, and subject to an aging management review, are
adequately managed. Calvert Cliffs ensures that this is accomplished by
either recognizing that there is a direct replacement refurbishment or
comprehensive performance and/or condition monitoring program in place,
or you could have an EQ program, or you will go through a very detailed
aging effect component by component evaluation, looking at the effects
on the functions, and then individually mapping them to the particular
program that you are going to use.
This option here did not prove to be very useful. There are
some complex assemblies that I believe we applied this to such as air
compressors that ended up not being in the scope of license renewal in
the end, but you are not going to take an air compressor down to every
tube and wire. We ended up realizing that those assemblies are
performance tested by STPs, et cetera, like the maintenance rule
requires you to do. So this did not prove to very fertile with respect
to avoiding a complete aging meeting review, but we thought it might.
The necessary elements that we are looking at when we
finally get to the component level, the environment, the materials, the
stressors, the operating experience, when we finally get to that level,
and this is at the component level itself and its individual
environment, we are looking at -- does the program have a method, a
periodicity, acceptance criteria that is relative to the elements of
concern, the intended functions, the aging effects that would tend to
degrade the ability of the component to perform its intended function?
Was there reasonable operating experience that exists that this program
was and will continue to perform its aging management?
And when we were -- when we structured this, we were kind of
going after it from a two-way strategy. One for mitigation -- and most
of our components, I stayed at the component level, have a two-prong
strategy. We looked for mitigation. Is there an activity that we can
put in place or is already in place that will mitigate the aging? And
then, can we come through and confirm it by doing inspections? So we
rely very little on analyzing things away on paper. We are looking for
direct measurements, confirmation through direct measurements.
We also look at the continued technical effectiveness of the
actual aging management program. Is it a self-correcting or a learning
activity? Is it -- what is the foundation of it? Is it based on
industry standards, acceptance standards, and is it administratively
controlled? So that there is some configuration management issues,
those types of things are addressed a la the previous presentation on
50.59.
When we looked at the bottom line, these are the statistics.
The existing programs, modified programs and new programs. There are
about 456 actual programs that we credited in the application, of which
329 existed and we didn't feel need to be changed at all. 101 of these
456 had to be modified slightly by either -- you either put the
inspector in the vicinity of the component to do a particular activity,
and we needed to turn that inspector and look for a particular aging
effect. That is the type of modification. Or we were actually putting
the component into the population of the program, and then there were 16
new programs. So that gave us a lot of confidence that the plant, in
fact, the maintenance strategies were addressing aging issues in an
acceptable manner. It was good news.
These existing programs broke down into the following
categories. There were 54 surveillance tests or STPs. There were five
special test and inspection activities that we were doing, that we will
continue to do. Maintenance procedures, engineering programs like
fatigue monitoring, operational procedures such as system walkdowns,
chemistry procedures. There were 10 maintenance programs that are more
formalized and then out of the PM program, there were 309 activities
that made up the 430 existing or modified.
The new programs, there were three categories. There were
six that we were going to extend existing engineering analysis on.
There were new evaluations, three new evaluations we were going to
perform, and there were primarily -- this was the bulk of them. There
were the new inspection programs which were really -- these are the
areas where we found that we typically, in the life of a plant you
typically don't go into the areas. These are digging up the pipes
underground. These are going into parts of a system that you typically,
you know, either you are looking for aging effects that are way on the
periphery, that these are unlikely but we couldn't prove they weren't
going to happen, so we want to go in and confirm that those aging
effects through a one time inspection would be -- would confirm either
that it is not happening, or if it is, we would then instigate an
ongoing or periodic inspection activity.
I am going to shift gears quickly to the time-limited aging
analysis part, because that concludes the aging management programs, and
this is just a repeat of what Steve talked about. These are the six
criteria for an aging -- for something to become a TLAA. These two,
first two involve assumptions, a 40 year assumption and incorporated in
the CLB are the process we -- these are two key things we looked at in
identifying, and then we used the bottom four to actually refine a very
large screen.
We have a docketed, an electronic docket which is also
OCR'ed, or it is word-searchable, and we created several strings and
categories of items to go through this large amount of information and
we actually ended up reviewing over 1700 current licensing basis
documents that fell into these -- either had some time-limited issues on
it or met some of the other screening criteria we established.
Out of those 1700 documents, we ended up with six areas
needing review, six TLAAs plus EQ, which is a lot of individual calcs,
right. And that was described in one particular chapter of the
application.
Now, recall that Part 54 requires us to ensure the analysis
remains valid. It has been or will be projected to the end of the
period of extended operation, or I have got an aging -- or I can manage
that TLAA by managing the aging that was the fundamental assumption in
the calculation.
DR. WALLIS: Can you give an example of analyses that do not
remain valid?
MR. DOROSHUK: You might have a fatigue analysis of a surge
line that looked at thermal stratification that you might have done
because it was an operational issue you discovered. You would have done
it to look at the 40 year period, because that is what you -- when you
discovered things in 1982, you didn't think about 60 years. So we, in
fact, probably did one, I think we did one through the Owners Group and
so we had a 40 year calc. Is that right?
But, however, we are going to manage that particular
calculation that wasn't analyzed for a 60 year period, because we are
going to manage that by counting the actual cycles on that location.
DR. WALLIS: It might be that there is an equation that is
valid out to 40 years but not to 60, so you have to modify the analysis.
MR. DOROSHUK: Yes. In fact, here where the --
DR. POWERS: That is fairly -- it is a very common thing for
anything that is cycling, to have done the analysis with a relatively
conservative assumption on the number of cycles per year. And that
because of the operational experience, you will find that you reduce the
number of cycles. That is a very common thing.
MR. DOROSHUK: Yes, sir.
DR. POWERS: What kind of level of conservatism do you think
you have on those things?
MR. DOROSHUK: Well, in the case of the class 2 piping in
the feedwater system, which has got design cycles of 7,000 cycles, that
7,000 cycles, we don't believe would be -- even come close to, because
it is limited to the number of heat-ups and cool-downs we would have on
the primary side where the class 1 piping is adjacent. Now, the only
interesting thing about that particular set of piping was that we have a
thermal stratification issue in a particular run, so we are not worried
about the 7,000 cycles as much as we are worried about the damage
occurring as a result of thermal stratification.
These are the TLAAs, EQ. We had a number of irradiation
embrittlement ones, pressurized thermal shock, heat-up and cool-down
curves, the L-top curves, fatigue. There were several locations in the
RCS that will need to be addressed. Main steam piping had a location at
the AFW pump. There was an analysis of the containment liner plate that
we are updating with the staff. The containment --
DR. WALLIS: Why does that fatigue?
MR. DOROSHUK: Marv, do you recall that one?
MR. BOWMAN: I am Marvin Bowman with BGE. That was a case
where we found some discussion in the FSAR that indicated that there
might be fatigue as a result of the temperature changes, seasonal and
plant operation.
MR. DOROSHUK: Right. It assumed -- the FSAR says that
where there was 40 cycles of annual outdoor temperature variations and
so we will go back. But these are full range cycles.
DR. WALLIS: Very few cycles.
MR. DOROSHUK: Right. But we talking probably minus 30 to
--
MR. BOWMAN: We couldn't conclude that it didn't need to be
looked at, and so we included it.
DR. UHRIG: Could there also be cycles associated with new
fuel going in?
MR. DOROSHUK: Fuel would not stay in the plant greater than
two years to three years, so it would be three years -- four years. Do
I hear five?
MR. BOWMAN: Six at most.
DR. UHRIG: I am talking about from the time it came out to
the next time you put fuel in. Thermal load.
MR. DOROSHUK: That would be part of the design on the fuel
and wouldn't be a 40 year issue, it would be more of the actual fuel
life for the particular assembly.
DR. UHRIG: I was talking about the liner. Anyhow, go
ahead.
DR. WALLIS: I guess you have intrigued me now. You say
seasonal variations. What is this time constant for the containment?
Heating up, does it heat-up in a day or a week or overnight? Because it
does respond to seasonal variations, but with what sort of a time
response?
MR. DOROSHUK: Well, I guess I didn't -- I didn't want to
intrigue you that much today on this topic.
DR. WALLIS: Well, it sounds like a yearly basis. That is
much too long, though. So I am kind of curious.
DR. KRESS: It has got a big surface area.
DR. WALLIS: A big surface area. Does it heat-up when the
sun shines on the containment?
MR. DOROSHUK: I don't have that information.
DR. POWERS: It definitely does.
DR. KRESS: I would say the time constant is not more than a
day.
DR. WALLIS: So it is more than 46 cycles.
MR. DOROSHUK: Right.
DR. SHACK: It is diurnal probably, but I mean they are
relatively small cycles, I mean by --
DR. KRESS: Those cycles are so small, you don't know where
--
DR. WALLIS: It is the same way that the windows crack in my
house when the sun shines on them.
MR. DOROSHUK: Well, we would hope it would not be the same
way, right.
DR. POWERS: Phenomenologically, some of them are not
affected.
MR. DOROSHUK: And those -- EQ, those were the TLAAs for
Calvert Cliffs, and there is one particular open item that, however, we
I think worked to closure on on one category of fatigue. It is not
shown here, but it will probably be shown in the staff presentation.
Where we are at is we are implementing these activities.
Either the existing programs are being captured in our licensing
commitment process, the modifications to the programs are being
initiated and changed as we speak. We have been doing this for the last
year or two. And the new programs are under development or are already
being implemented. And what we are also at this point looking at is how
do we institutionalize these commitments inside the normal site
management, so that when the UF hardware changes, when there might be a
licensing basis change that might come out of a new regulation? How do
we then go back into and perform a mini-IPA, if you will, on what might
used to be non-safety-related equipment? You might end up having that
now come in scope. The programs, the basis of these programs capturing
that.
And making sure that you've tied in these aging effects or Aging
Management Review findings, although we haven't discovered anything new
here with respect to aging. It's been happening. It is a new focus and
so you do have to look at your operating experience units and making
sure that when they do get a hit either in the industry or on our own
site that when that aging experience comes into the engineering
organizations it is processed in a manner that takes into account the
60-year horizon, not the 40-year horizon.
We have not found any aging that automatically starts
happening at year 40 or in fact changes in any way, shape or form --
DR. SHACK: Was that a shock to you?
MR. DOROSHUK: No. No --
DR. SEALE: Quite the contrary.
MR. DOROSHUK: It was anticlimactic, I guess.
[Laughter.]
MR. DOROSHUK: A lot of money to find that you are doing a
lot of good work.
DR. WALLIS: That question would seem to be are there aging
effects which become critical during the next licensing period.
MR. DOROSHUK: We haven't found any aging occurring in any
components that would end up costing us -- we haven't identified any
capital projects as a result of this.
DR. WALLIS: So the horizon where these things begin to
become important is out to 90 or 100 years or so?
MR. DOROSHUK: Well, they are already here. For example the
steam generator --
DR. WALLIS: And you know how to deal with them?
MR. DOROSHUK: Yes, but as a result of this application,
we -- you see some cables. We got like 67 cables we are going to
replace. We will probably end up as we get into some of these
inspections we may find some stuff but as a result of this evaluation
and the operating experience to date, we have not identified any capital
projects as replacing entire piping systems.
DR. POWERS: Did you in the course of coming to this
conclusion, you had no capital projects to go to 60-year life? Look and
see. Would you have any capital projects if you went to 80 years life?
MR. DOROSHUK: The vessels themselves we believe are good
out beyond 80 and we have a 60-year SER.
DR. POWERS: Out beyond 80.
MR. DOROSHUK: There might be in the internals area,
depending on how some of these inspections go, there might be some areas
that would need to be looked at, but we didn't get there.
DR. POWERS: You didn't have any doubts about your buried
piping or anything like that?
MR. DOROSHUK: No. In fact, we have dug up a number of feet
of our buried piping already and inspected it and it is amazing when you
take off the wrap and it's brand new. You can still see the stamps on
it and it's shiny. That's not to say that it's all of our piping
system. We have replaced a lot of feet of pipe in the plant from
erosion corrosion. We have completely replaced our saltwater system of
piping above-ground.
DR. POWERS: That is a different set of issues there.
MR. DOROSHUK: Those were all aging issues.
DR. POWERS: Well --
MR. DOROSHUK: Well, vulcanized rubber wasn't vulcanized
very well in 1970 so --
DR. POWERS: Yes, there is a big change in that.
MR. DOROSHUK: But they are doing it better these days.
DR. POWERS: Much better.
DR. SHACK: Just when you replace for erosion corrosion, do
you go to a Chrome Moly steel?
MR. DOROSHUK: Yes, and now in the feedwater system we are
using chrome -- we have gone to Chrome Moly.
That concludes -- I guess just one last thing is the
schedule and where we are at and just to highlight that we are, we do
want to acknowledge the fact and appreciate the fact that the ACRS has
moved their schedule up almost a year and so we appreciate you agreeing
to begin reviewing the material and we certainly will be open to any
more comments and questions that you have through the rest of the
presentation.
DR. WALLIS: Well, everything sounds great, but are there
certain issues that require more investigation or more knowledge before
they can be resolved?
MR. DOROSHUK: We have not discovered any. I guess we have
got a few areas that we still are trying to develop the final inspection
agreements with the Staff and that is to refine -- for example, we said
at one time inspection for some areas of the saltwater and the Staff has
said no, but we would like to see you do it a couple of times so we are
considering incorporating that change, but we haven't -- we are not
stuck on anything yet except for maybe those --
DR. WALLIS: There's nothing you have identified that say
the entire industry has to do research on or something in order to
resolve an issue?
MR. DOROSHUK: No, sir.
We have identified a number of issues that the industry is
conducting research on. In the non-EQ cable area there was a
significant amount of research going on at NRC and by the industry
themselves. Clearly we are engaged in that. That could result in us,
if there is a condition monitoring program that's developed we could
implement that as a result of a different set of conditions.
There is research in fatigue that is ongoing and that has
had to have been addressed. How do we adjust and make sure that those
issues are reviewed here on the Calvert Cliffs in lieu of a long-term
generic solution, so we have come head to head with some of those.
DR. SEALE: The Staff made it clear that the PRA and those
kinds of considerations are not a fundamental part of the license
renewal process itself but that PRA insights could be useful in making
certain value judgments about alternative ways of doing things,
inspection program timing perhaps, and things like that.
Could you give us a brief idea of how you have used PRAs so
far?
MR. DOROSHUK: I think there's two areas where we have used
PRA. We were scoping the plant according to the license renewal rule
when the maintenance rule came into effect, so Calvert Cliffs used the
scoping results in all those active components and provided the scoping
for the maintenance rule, and we basically married our engineering
services with those of the PRA Group to produce the maintenance rule
scope that is being used now, and of course is in a living state.
That didn't change the license renewal scope but it allowed
integration on site and so there wasn't in our mind a crack. We made
sure there wasn't.
DR. SEALE: Yes.
MR. DOROSHUK: The second part, where we didn't actually use
PRA but when we got into the aging effects you used more of a
qualitative risk assessment on, how aggressive was the aging, what is
the operational experience. We didn't do an failure modes and effects
analysis in this area but you use more qualitative -- how aggressive is
my aging management program given the aggressiveness of the aging?
So from the integrated plant assessment side, the risk
insights were more in what programs are you going to use and that was
more qualitative risk assessment. On the environmental side we did do a
full severe accident management analysis using our PRA. We do have a
Level 3 PRA. We do not have the shutdown portion. We did identify over
150 mitigation options which ballooned out of course because they become
separate and different options in and of themselves and evaluated all of
those, using the NRC guidance for risk analysis and cost benefit
procedures that were used on Watts Bar, so we did the Watts Bar
procedure.
We did identify one modification to the plant as a result of
that analysis and that is being implemented and that is we are going to
convert some doors to a watertight door and that removes what percentage
of the flooding risk.
MR. BOWMAN: Two to three percent.
MR. DOROSHUK: Two to three percent -- of core damage, and
there were three SAMAs identified that were not age related that are
going to be considered by Calvert Cliffs outside of license renewal
space but two of them I believe are -- one is not realistic. One says
get really reliable batteries. Well, we just replaced our batteries and
we got the best you could buy so there are no better batteries so this
idea that you can get a 100 percent reliable battery just doesn't exist
so that particular SAMA doesn't seem reasonable.
The second one, that we looked at was on the border of being
cost-effective, was going in the ESFAS logic going from a two out of
four to a three out of four logic, and we don't believe, even though
we've looked at this and we think you could actually physically make the
plant do this, we don't necessarily believe that -- you might be able to
get analytical risks down, but from just general feeling, waiting for
another trip to get the real trip doesn't seem logically correct to us.
So we're taking a look at that, and we don't believe that that may
necessarily be the right thing to do.
And the third thing is -- I guess has to do with some fire
hoses and being able to supply some fire water, that's putting a truck
with another hose, and so it's not a big issue. So we did have a very
significant look at the plant from a probabilistic assessment in the
EIS, which is not part of this particular review, and that was reviewed
by the NRC. So it actually was done in a very extensive --
DR. APOSTOLAKIS: Do you remember what your core damage
frequency was?
MR. DOROSHUK: The overall CDF is 2.1 times 10 to the minus
4. And we've taken a look at the passive failures that are contained in
the Calvert Cliffs PRA, and this is literally a back-of-the-envelope,
Mr. Apostolakis, because we were told you'd ask these questions. So let
me try to just -- we've taken a look at what different would this make.
And we don't think it makes any.
DR. APOSTOLAKIS: This being?
MR. DOROSHUK: The passive failures inside the PRA. And we
don't think that it would result in any change in scope for our
application. If you look at the passive failures, they are LOCAs, steam
generator tube ruptures, reactor coolant pump seal failures, pressurized
thermal shock, vessel failures, floods, fire barriers, service water and
component coolant leakage, seismic challenges to our condensate storage
tanks, high-wind challenges to these tanks that are all on the scope of
license renewal already, turbine missiles and barriers are all on the
scope of license renewal already, containment, instrument error
integrity, and the buses and power cables. They're all in the scope
already. This is from a back-of-the-envelope brainstorming session.
When you look at what passive features of the plant have been modeled
already, it doesn't go -- it's already included.
Now what gives us comfort from this is that the region
inspection utilized a risk-informed approach to verifying did we scope
properly, and they came in and they said okay, fine, we will look at
some things you said were in scope, we will also look at some things
that you said were not in scope but are risk-significant. And they took
five systems and a structure or two, and they climbed through that
pyramid from top to bottom in our licensing basis and looked at the
individual components of each of those systems or sampling and validated
that in fact they did not perform any of the functions required by Part
54.
There was one outbuilding, fire pump house where we had a
couple of fire pumps in it that there was a berm, a concrete berm, that
was in between the two pumps, and the berm is there to prevent an oil
spillage contaminating and catching fire to the second pump, and it was
in an area of 50.48 or Appendix R that was gray enough to us that we
said fine, we'll put it in scope. So even though the rule is
deterministic, I think that the Part 51 and the regional inspection
really did pull the string on was there risk-informed information used
in reviewing the application.
DR. APOSTOLAKIS: I just did a quick calculation that
disturbs me. Your core damage frequency is 2.1 10 to the minus 4 per
year.
MR. DOROSHUK: Um-hum.
DR. APOSTOLAKIS: Which means according to the Regulatory
Guide 1.174 you would not be allowed to make a change that would be as
high as 10 to the minus 5 in the core damage frequency. That's what
1.174 says. You started operating in 1974, so you have operated for 25
years, so if there is no license renewal, you will have another 15.
Fifteen years times 10 to the minus 4 nonallowed core damage frequency
is 1.5 10 to the minus 4 probability that the NRC staff has found
unacceptable because your core damage frequency is already above 10 to
the minus 4. They wouldn't allow any changes that will give you that.
If you are allowed to go to 60 years, and you maintain your
2.1 10 to the minus 4 core damage frequency, then the NRC is accepting
an additional probability of core damage of 4.2 10 to the minus 3, which
is about 30 times greater than what the NRC does not allow in 1.174. In
other words, if you work with probabilities, not core damage
frequencies, you get a major inconsistency there, which is not your
problem, it's our problem. It may become yours, but right now it's
ours.
[Laughter.]
And I don't know what that means. I mean, in one place we
are not willing to accept an increase in the probability of core damage
for the remaining life of the plant of about 10 to the minus 4, but we
may very well renew the license of the plant for another 20 years, which
means we have a probability of 4 10 to the minus 3 core damage. I mean,
does the total probability count for anything?
DR. KRESS: No.
DR. APOSTOLAKIS: Why not?
DR. KRESS: Time, these are random events, George.
DR. APOSTOLAKIS: Yes.
DR. KRESS: It's like flipping a coin.
DR. APOSTOLAKIS: Yes.
DR. KRESS: How many heads and tails are you going to get in
the next 15 flips doesn't have any knowledge of what happened during the
last 15 flips. So you throw away the 40 years, because it hasn't had
the accident.
DR. APOSTOLAKIS: No. That is why I did the calculation
only for the remaining 15.
DR. KRESS: It's only for the remaining 15.
DR. APOSTOLAKIS: That's what I did.
DR. KRESS: Okay. Is that what you did?
DR. APOSTOLAKIS: Yes.
DR. KRESS: Okay. That's legitimate. Don't count the past
40 years.
DR. APOSTOLAKIS: No.
DR. KRESS: Okay.
DR. APOSTOLAKIS: So maybe we should discuss this among
ourselves at some point.
DR. FONTANA: I don't think we're going to solve that right
now.
DR. APOSTOLAKIS: No, I know, and I'm sorry I raised it.
DR. FONTANA: No, you're not.
DR. APOSTOLAKIS: I really am not.
DR. FONTANA: Any additional questions of Barth.
Well, thank you very much. That's very informative.
DR. POWERS: It was a very nice presentation.
DR. SEALE: I think you could write a book now, couldn't
you?
MR. GRIMES: While the staff is preparing to discuss the
safety evaluation, I will point out during the stakeholders meeting
yesterday it was Mr. Lochbaum from UCS who basically raised that same
question about whether or not a policy that recommends essentially
increasing the risk by a half again by extending the license and the
Chairman's response was that's not the way her statistics work. So I
think that there's going to be some more dialogue about what the
relative risk is.
In the meantime I would like to introduce Dr. Sam Lee, who
is going to chair a session that includes Barry Elliott, Paul Symansky,
and John Fair, who were principal contributors to the staff's safety
evaluation for Calvert Cliffs.
MR. LEE: My name is Sam Lee. I'm from the License Renewal
and Standardization Branch, NRR. I'm going to give you an overview of
the staff review of the staff review of the BG&E license renewal
application.
Today, I have several in here to help me understand the questions here.
The staff review process. These are some of the guidance
documents that the staff considered when they were reviewing the BG&E
application. That is the draft standard review plan for license
renewal, which contains a lot of information from the period staff
review of the industry reports. And we had the SOC for the license
renewal rule, which provides some guidance, and NEI document 95-10
provides guidance for the industry, and the staff has proposed to
endorse 95-10 in the Draft Reg Guide. And also, there is an NRR office
letter on the license renewal process.
Here are additional related activities. There's a lot of
NRC industry management meetings. They are regular meetings. And every
month, the NRC division directors meet with the BG&E and also Oconee
management to check up on the status of the review. And also every two
months, the NRC license renewal steering committee meets with the NEI
license renewal working group.
We have compiled a list of license renewal issues and these
are mostly NEI's comments on the draft standard review plan. The
objective is for the staff to work through these license renewal issues
and provide improvements to the standard review plan.
The license renewal issues are different from the generic
safety issues, the GSIs, which are documented in NUREG 0933. We also
have a license renewal inspection program. You heard a lot of that from
the BG&E presentation. This is conducted by Region I, and they
completed two inspections at BG&E. One is on scoping; one is on aging
management programs.
Here is the table of content of the BG&E SER. It basically
follows the structure of the rule. Chapter 2 discusses the structures
and components subject to aging management review. Chapter 3 discusses
the aging management, and Chapter 4 discusses the time-limited aging
analysis. And I'll go into this in a little more detail.
DR. WALLIS: Just to clarify, you're developing a safety
evaluation report without having a standard review plan because it's a
draft?
MR. LEE: That's correct.
DR. WALLIS: So the two are happening at the same time?
MR. LEE: Actually, the draft standard review plan has been
out for like '97 -- two years. So it's a little ahead of the BG&E. But
it's still a draft.
Okay. Chapter 2 is the structures and components subject to
aging management review. The staff had previously approved the BG&E
methodology for identifying structures and components subject to
aging-management review. Subject to aging-management review means
structures and components that are passive, long-lived, and within the
scope of license renewal. The staff has verified the implementation of
the methodology by, I guess, by a two-step process. The first step is
to review the systems and structures and components within scope, and
the second step is to review whether the passive and long-lived portions
have been identified.
After this review, we identify some open items, and they
generally include what we call the cascading issue, which is how much of
the supporting non-safety related structures and components should be
subject to aging-management review and the staff is working through this
with BG&E.
Chapter 3, that's aging-management review, and as BG&E
described earlier, the application is structured around systems. So we
have twelve sections in Chapter 3 that go by system by system
evaluation, and because there are some programs that are common to many
systems, we have pulled them out and then we have a separate section
that's called the common aging-management program, and they range from
fatigue monitoring, chemistry, to walkdown, to this RD program, and I'll
discuss two of these, I'll discuss the fatigue and the RD, and I'll give
you an example of a system that we did.
MR. LEE: This is fatigue monitoring program.
DR. SEALE: These are programs that currently exist that are
to be incorporated into the aging management program presumably or --
MR. LEE: Some of these exist, like chemistry program does
exist, fatigue monitoring program exists, corrective action --
DR. SEALE: Right. But the rest of them are already there;
you're just -- they're going to have to look at 60 years now instead of
40, so to speak?
MR. LEE: Well, actually, we look at all the programs for
60.
DR. SEALE: Yes. I understand. Okay.
DR. WALLIS: I thought they -- have they already submitted
this and your reviewing it or am I wrong?
MR. LEE: They submitted the application.
DR. WALLIS: It's already submitted.
MR. LEE: Yes, already submitted.
DR. WALLIS: Okay.
DR. SEALE: They get carried from the current basis to the
new basis.
MR. LEE: Okay. Section 3.1.1 is the fatigue monitoring
program. BG&E monitors the plant operation parameters to track the
number of transients so that they can calculate the fatigue usage caused
by transients at limited locations.
The fatigue usage is a term in the ASME code that is used to
quantify fatigue, and this -- and that's a design limit in ASME code
that the fatigue usage should be less than 1, and BG&E's fatigue
monitoring program would cause corrective action before CUF gets to one.
DR. WALLIS: That makes it acceptable.
MR. LEE: That's correct.
DR. SEALE: I have an embarrassing question to ask.
MR. LEE: Okay.
DR. SEALE: There is an outstanding generic issue on
fatigue.
MR. LEE: I'll get into that in my next slide.
DR. SEALE: All right.
MR. LEE: Okay.
DR. SEALE: All right. I won't embarrass you, then; I'll
let you embarrass you yourself.
DR. MILLER: There are several outstanding -- there are
several generic issues.
MR. LEE: This is the age-related degradation inspection,
ARDI. This is a new program. There are certain aging effects that are
unlikely except you cannot rule out completely, so they're kind of a
gray area, and so what BG&E decided to do is they'll do a one-time
inspection to confirm that the aging effect is not there, and if they
should find it there, then the plant's corrective action program will
kick in and that will cause them to do corrective action, like the
regular inspection and such. And that's the purpose of the ARDI. Okay.
Like we discussed earlier, there are open items in the ARDI,
and this relates to when is the one-time inspection appropriate. We
found places where the aging effect should be subject to regular
inspections, and these are, I guess -- the two examples I put in here is
the coating degradation and corrosion due to leakage. So this is going
to be discussed with BG&E.
Here is an example of a system. Section 3.2 of the SER is
on the reactor vessel, the internals, and the RCS. And here, we list
the aging effect and the corresponding aging management program.
For example, corrosion, you get water chemistry program,
that's an existing program. And for the denting and cracking of the
steam generator, we have the eddy current testing. That's an existing
program. And for various degradation here, we have the Section 11 ISI
program. That's also an existing program. And for Neutron
embrittlement of reactor vessel, that's a reactor vessel material
surveillance program. For BG&E, they have additional capsules that
they're irradiating for a period of extended operation.
Thermal aging of the cast austenitic steel, and BG&E propose
a program and we reviewed that. That is acceptable. It's a new
program. Embrittlement of the internals -- the program is a modified
ISI program which relies on an enhanced inspection. And for cracking of
Alloy 600, there's an Alloy 600 program, and fatigue, there's a fatigue
management program.
And here is the GSI-190. In the Section 3.2, there is an
item in the RC related to GSI-190 which relates to the environmental
effects on fatigue. The staff is requesting a technical rationale to
address the environmental effect on fatigue for a period of extended
operation.
We have open items also in Chapter -- Section 3.2, and some
of these relate to the augmented inspection where the staff believe that
additional inspections should be performed based on operating experience
such as cracking of the pressurizer shell and small-bore piping.
The next chapter of the SER is on time-limited aging
analysis, and here are some examples, and you have seen BG&E's list
earlier. You have EQ, you have fatigue, you have prestress loss of the
containment tendons and you have PTS of the reactor vessel.
For BG&E, the staff had previously issued an SER indicating
that PTS is acceptable for 60 years.
DR. WALLIS: Prestress loss -- this is something that --
they've been creeping or something?
MR. LEE: That's correct, yes.
And here is the evaluation of a TREA. EQ is a TREA and BG&E
is proposing to use the 50.49 EQ program to manage the aging effects for
EQ equipment. And as BG&E indicated earlier in their presentation, the
staff reviewed BG&E's 50.59 EQ program, and we have back-and-forth
exchange with BG&E. In the end, we found this acceptable to manage
aging of EQ equipment for license renewal, and that is one example of
the credit for existing program issue.
There are a lot of -- actually, most of the programs for
license renewal is existing programs. Industry's position is that
existing programs, they are acceptable for current term and they should
be acceptable for license renewal before staff review, and we are going
to prepare a Commission paper and ask for guidance on how to address
that.
Here is the summary status. The staff issued the SER on
BG&E in March with open items and confirmatory items, and like we said
earlier, most of the programs are existing programs. However, we do
find places where existing programs should be augmented, and we are
preparing a Commission paper on this credit for existing program issues,
which is due the end of May. And the final SER for BG&E is due in
November.
That concludes my presentation, so if you have any
questions.
DR. WALLIS: Well, I've heard two presentations which say
everything is fine. I'm not quite sure what else we need to do. Do we
need to dig into anything in particular? Is there anything that ACRS
should pay attention to besides saying that we were impressed with what
we've heard?
MR. GRIMES: I would like to suggest that we -- we didn't
mean to leave you with the impression that everything is fine; we meant
to leave you with the impression that we've done a lot of work and we've
developed a fairly detailed safety evaluation that documents how aging
effects are going to be managed, and as soon as we resolve 28 open items
and 20 confirmatory items, then we believe we will be able to reach the
conclusion that the applicant has satisfied 50.49 for which we can
recommend that the Commission grant this new license.
Sam covered the safety evaluation in terms of its major
areas and provided some illustrations. We were hoping that you would be
able to look at least across some of the major programs and say that
you're satisfied that we've addressed it at the appropriate level or
with the appropriate standards. You can pick and choose amongst the
open items in terms of testing our decisionmaking processes. There are
a variety of different ways that you can develop a confidence in the
work that we've done and we're prepared to support you in any way that
you wish to proceed.
DR. UHRIG: I have a question. This bullet on the last
slide, Commission paper on credit for existing programs, is this -- what
is the nature of the issue here?
MR. LEE: The nature is, I guess, like what we discussed
earlier about what we found from Oconee and BG&E's application is about
80 or 90 percent of the programs are existing programs, programs to
manage aging.
DR. UHRIG: Is there an implication here that the Commission
might not accept that?
MR. LEE: Well, we are asking for, I guess -- we realize
that we are trying to get some efficiency in the license renewal
process. What we perceive the rule is saying there is we need to review
all the programs whether they're existing or not. So a lot of resources
are being used to review 80 percent of programs. We don't want to keep
looking at Section 11 ISI over and over.
MR. GRIMES: Dr. Uhrig, this is Chris Grimes. This issue
about credit for existing programs is not germane to Calvert Cliffs or
Oconee because we have reviewed all of the programs to the level of
detail we felt was appropriate to make a conclusion across the whole
scope of passive long-lived systems, structures and components.
The question for the future is, will the next applicants
have to have their EQ program or their ISI program tested the way we
tested it on Calvert Cliffs and Oconee, or can some things simply be
taken for granted as standard practices that are recognized as managing
aging effects.
So from that standpoint, this issue is one -- it's
forward-looking and addresses the effectiveness and the efficiency --
DR. UHRIG: It doesn't relate to the Calvert Cliffs.
MR. GRIMES: It will not result, in our view, in the
Commission being -- having anything to decide on Calvert Cliffs or
Oconee.
DR. UHRIG: Thank you.
DR. FONTANA: If there are no immediate questions, you have
-- the committee has a draft version of a letter which I'm sure is going
to go through quite a few metamorphoses before it goes through. Are
there any questions that you would like to ask the staff relating to
what you would like to put into that letter? That is, while they're
here.
DR. POWERS: Our attention on this letter says this is an
interim report, is it not?
DR. FONTANA: Correct.
DR. POWERS: And we're going to come back -- there's going
to be a final SER. Is our intention to write on the final SER?
DR. FONTANA: Sure.
DR. POWERS: Okay. So this is simply a letter that says we
have not or we have identified a show stopper.
DR. FONTANA: That's right.
DR. MILLER: Staff is telling us they've seen no show
stoppers.
DR. POWERS: I know what they -- I know what everybody hopes
we write and I know what the draft says will satisfy everybody's
aspirations right now, but those drafts do have a habit of evolving a
tad.
DR. SEALE: Well, I think we all have to admit that we're
also interested in the issue that was raised earlier about the risk over
an additional 20-year period or whatever the time may be, and we really
-- if the Commission is talking about looking at that issue anyway, I
think it's something we may want to comment in that context.
DR. POWERS: Well, we may comment on that, but I think
that's --
DR. SEALE: But that's not what we're talking --
DR. POWERS: I guess my own view is that the -- right now is
I presume the Commission in passing the license renewal rule did those
elementary calculations themselves and the inconsistency lies not -- the
difficulty and the lack of consistency, first of all, is not unusual in
the regulations, and second of all, it lies in another quarter, not in
this quarter. I would take that as not these guys' problem, in other
words.
DR. UHRIG: Well, it's the same issue that came up back in
the glorious days when somebody projected 1,000 plants.
DR. POWERS: Oh, yeah. Uh-huh.
DR. UHRIG: You had to get the core damage frequency if
you're going to have 1,000 plants around -- have an accident every ten
years. That was not acceptable.
MR. GRIMES: If we get a -- if we had our druthers, I think
that the staff would appreciate if you would -- if you want to address
the risk aspect, then please, you know, write me a letter, because the
renewal program is my responsibility. And to the extent we coordinate
closely with the rest of the high priority activities in NRR, we're
involved in risk-informed -- risk informing Part 50 to the extent that
we maintain compatibility across all of the licensing basis.
DR. KRESS: Does 50.54 right now tie your hands?
MR. GRIMES: Part 54, the license renewal rule, does not
have a provision in it nor did the Commission explicitly consider a risk
aspect.
DR. KRESS: It doesn't prohibit it.
MR. GRIMES: It doesn't prohibit it, and we've explained how
we've tried to use risk insights to look at an extension of a
deterministic licensing basis, but -- in much the same way that we've
tried to give BG&E some closure to where we're going with this issue.
If I could get a letter you basically says we're satisfied to a certain
extent and you want to pursue certain open items, at least we know then
what to plan for the future.
I want to emphasize that although the schedule shows that
the final safety evaluation -- actually, it will be a revised safety
evaluation -- will simply fold in changes according to the resolution of
the open and confirmatory items and re-issue the SER in a complete form.
But to the extent that we can improve on that November schedule, we may
be asking you for a decision sooner.
So to whatever extent that you can help us find some closure
in certain areas and attention or consideration or open items or subject
you want to pursue in other areas, that would be very useful for us.
DR. POWERS: I think we're going to try to be following our
kinds of things that we did for AP600, which essentially said, here are
the topics we've looked at at this particular meeting and we've -- here
are our points of view on those topics, and if history repeats itself,
that's kind of the end of it. We're not going to preclude ourselves
from re-raising issues, but in general, we don't. They're are an awful
lot of topics to cover here.
MR. GRIMES: That's fair. That's about the rules we have.
DR. POWERS: Yes.
DR. FONTANA: If there are not any additional questions, I
want to point out this is my last meeting with the ACRS, and the new
chairman of this committee will be Dr. Mario Bonaca. We had to hunt
around for someone with the same first name so it wouldn't confuse you
guys too much, you know, make it easier for the transition.
So again, thank you very much, and good luck to you all and
to Dr. Bonaca.
DR. POWERS: You're not going away. You don't get out of
letter writing for the next three days.
[Laughter.]
DR. FONTANA: I take my speech back.
I'll turn it back to the Chairman.
DR. POWERS: I want to thank everyone for an extraordinarily
good set of presentations, well presented and well thought out, very
useful to the committee.
DR. SEALE: We have a comment over there from --
MR. DOROSHUK: Mr. Chairman, I would like -- my name is Bart
Doroshuk, BG&E, and I want to -- for our clarification, did the
committee agree today that the risk question was not a part of the
Calvert Cliffs application and it was to be handled in a separate
quarter?
DR. POWERS: I think that's a fair assumption. We're not in
the business of making agreements, but we're in the business of advising
the Commission, and we may advise them that they need to think about
risk.
MR. DOROSHUK: But it would not be part of the --
DR. POWERS: I don't think it's peculiar to Calvert Cliffs.
DR. KRESS: That's an opinion, of course.
DR. POWERS: Yes.
DR. KRESS: The committee has not debated the subject --
DR. POWERS: Yes.
DR. KRESS: -- or discussed it.
MR. DOROSHUK: Right. I appreciate your patience with my
inappropriate use of agreement.
[Laughter.]
MR. DOROSHUK: We need to go back and explain to our
management the results of the meeting and I guess our understanding is,
is that the current thinking was that this is an issue that would be
separate from the application review and will remain separate.
DR. POWERS: Yes. What the Commission -- we can't tell you
what the Commission is going to do.
MR. DOROSHUK: Yes, sir. I understand. Thank you.
DR. POWERS: We will be writing a letter, maybe two.
I think that brings the oral presentations to a close and
our need for transcription to a close. Unfortunately, it does not free
the members up.
[Whereupon, at 6:12 p.m., the recorded portion of the
meeting concluded.]
Page Last Reviewed/Updated Tuesday, July 12, 2016
Page Last Reviewed/Updated Tuesday, July 12, 2016