Meeting of the Joint Subcommittee on Reliability and Probabilistic Risk Assessment and Regulatory Policies and Practices - September 24, 1999
UNITED STATES OF AMERICA
NUCLEAR REGULATORY COMMISSION
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
***
MEETING: RELIABILITY AND PROBABILISTIC RISK
ASSESSMENT AND REGULATORY POLICIES AND PRACTICES
U.S. Nuclear Regulatory Commission
11545 Rockville Pike
Room T-2B3
White Flint Building 2
Rockville, Maryland
Friday, September 24, 1999
The subcommittees met, pursuant to notice, at 1:00 p.m.
MEMBERS PRESENT
GEORGE APOSTOLAKIS, Chairman, Subcommittee on
Reliability and Probabilistic Risk Assessment
THOMAS S. KRESS, Chairman, Subcommittee on
Regulatory Policies and procedures
MARIO BONACA, ACRS Member
JOHN J. BARTON, ACRS Member
ROBERT E. UHRIG, ACRS Member
WILLIAM J. SHACK, ACRS Member
JOHN D. SIEBER, ACRS Member. P R O C E E D I N G S
[8:30 a.m.]
DR. APOSTOLAKIS: The meeting will now come to order. This
is the second day of the Joint Meeting of the ACRS Subcommittees on
Reliability and Probabilistic Risk Assessment and on Regulatory Policies
and Practices. I am George Apostolakis, Chairman on the Subcommittee on
Reliability and PRA. Dr. Thomas Kress, on my left, is the Chairman of
the Subcommittee on Regulatory Policies and Practices.
ACRS members in attendance are John Barton, Mario Bonaca,
William Shack, Jack Sieber, and Robert Uhrig.
The purpose of this meeting is to review the proposed
rulemaking plan and study for development of risk informed revisions to
10 CFR, Part 50, domestic licensing of production and utilization
facilities. The subcommittees will gather information, analyze the
relevant issues and facts, and formulate proposed positions and actions
as appropriate for deliberation by the full Committee.
Michael T. Markley is the Cognizant ACRS Staff Engineer for
this meeting.
The rules for participation in today's meeting have been
announced as part of the notice of this meeting -- previously published
in the Federal Register on September 3rd, 1999.
A transcript of the meeting is being kept and will be made
available, as stated in the Federal Register notice. It is requested
that speakers first identify themselves and speak with sufficient
clarity and volume so that they can be readily heard.
We have received a request from Mr. Jim Riccio, public
citizen, for time to make oral statements to the subcommittees regarding
matters discussed during this meeting. The ACRS has reviewed SECY-98-
300 in December '98 and issued a report to the Commission dated December
14, 1998.
In a Staff Requirements Memorandum dated June 8th, 1999, the
Commission directed the Staff to pursue the proposed Option 2 and Option
3 approach. The joint subcommittees previously met on July 13, 1999 to
discuss Staff plans on this matter.
The Staff has met with the Nuclear Energy Institute and
licensee representatives several times to discuss options for revising
10 CFR, Part 50 and possible pilot participation. The Staff also held a
public workshop on September 15, 1999 to discuss possible changes under
Option 3.
Before we start with the Staff, I have a couple of comments
to make. A lot of the risk informed approaches that we have discussed
in the last two, three years rely on importance measures, and I am not
sure that we all understand what these measures mean and the implication
of their use. In fact, I was doing some calculations yesterday and I
found some things that are interesting I would say, so I know this comes
as a surprise to everyone, so I don't expect answers but I think it
would be useful to at least discuss some of these issues maybe at some
later time to try to come up with some answers.
I believe you are getting copies of this -- somebody is
bringing them, okay.
Let's take a very simple case. There is only one accident
sequence. You can't get simpler than that -- one initiating event and
one protection system. The core damage frequency or the unavailability
is simply the product Fq: F is the Frequency of the initiating events
and q is the unavailability of the protection system. Right? It's the
simplest possible case.
Now I can calculate the two common measures, like Fussell-
Vesely and the Risk Achievement Worth. Fussell-Vesely tells me that I
should take the minimal cutsets that involve the unavailability of this
protection system, and there is only one, Fq, and divide it by the
total, so Fq divided by the total is one, so this is the Fussell-Vesely
of the system. It is also the Fussell-Vesely measure for the initiating
event.
To get the Risk Achievement Worth I am supposed to find the
new CDF that would result with Q equal to one, in other words assuming
that the protection system is always down, what is the new CDF? Well,
it is just F, and divided by the total CDF of the base case and the
result is 1 over q. Right? So this is a very simple calculation.
Now I decide to spend money and add protection systems, so I
add a number N of them, so the new CDF now is Fq -- the Frequency of the
initiator -- times the unavailability of my original system times the
product of the unavailabilities of all the other systems that I added,
and for simplicity I am assuming independency. That's a seven-day
issue.
I calculate now the new Fussell-Vesely and the new Risk
Achievement Worth of the original system. Well, Fussell-Vesely is again
the ratio of the minimum cutset over the total, so it is still one, and
RAW set q equal to one, so you have got F times the product of the qj,
divide by the total. It is still 1 over q.
So the two importance measures of the new system have not
changed, even though I added a number of additional protection systems.
The question is really is the system as important as before?
According to these two measures, yes. The two measures have not
changed. Now intuitively, though, you would say no, I don't care. If I
add a hundred more systems, even if this one fails, who cares?
So it seems to me that there is a problem there, that the
measures are insensitive or appear to be insensitive to such drastic
changes in the design. Now the question is so what? What are you going
to do? Well, I don't know. I mean this is just something that I
realized yesterday, but it bothers me and if we are to -- and one can
have other things that are not as impressive as this one by adding
failure modes and so on, but the question really is do we understand
what these importance measures mean to the degree that we can
comfortably use them in regulations, routinely, because now we are
talking about changing, revising the scope of systems, structures and
components and I believe the major tools to make that process risk-
informed are the importance measures, and this is a trivial case
obviously, but sometimes trivial cases give you some insights. I don't
know what happens if you have a complete PRA with thousands of minimal
cuts sets and so on. I haven't looked into it, but it just doesn't make
sense that the importance measures are so insensitive.
So for example I was reading a paper from Duke Power some
time ago, how they implement -- how they use PRA to evaluate online
maintenance configurations, and they have a very nice table there where
they say we will put the components into categories depending on the
value of the Risk Achievement Worth and in one group they have the
components whose RAW is 100 or more, so if EDQ is 10 to the minus 2,
which is a reasonable unavailability, this RAW will be 100, and then
they impose on themselves a requirement that between refueling outages
these systems that have a RAW of 100 or more should have no failures.
They are so important they should have no failures, okay?
Now that presumably means that you have to be very careful
with your maintenance and quality assurance and all that. It implies
there is an expense there, so now if that same utility said, well, hell
with it, we don't want to do that all the time -- it's a pain in the
neck -- we are going to spend -- this is crazy of course, but we are
going to spend a few hundred thousand dollars to add systems, so I don't
have to worry about quality assurance.
The NRC comes back and says sorry, your RAW is still 100, so
the money you spend there is irrelevant. Your RAW is still 100. You
still have to do these things, okay? -- so this is the thing. Yes,
Mary?
MS. DROUIN: George, I am not going to argue with your
mathematics there because they aren't incorrect, but the --
DR. APOSTOLAKIS: Are incorrect?
MS. DROUIN: Not incorrect -- but what is misleading here is
that you have only looked at the ratio of looking at the Risk
Achievement.
It is improper when you are looking at these important
measures just to look at the ratio calculation. If you took the same
thing on the Risk Achievement and didn't do it in the ratio, you would
see a different result. If you just looked at what the delta CDF is --
DR. APOSTOLAKIS: Wait, wait, wait. That was my next
comment, that using these measures may not be appropriate precisely
because they are ratios --
MS. DROUIN: That is exactly right.
DR. APOSTOLAKIS: The possible solution is to actually look
at the delta CDF, but that is not what is done. That is not what is
done. If you go back to the risk informed graded quality assurance
guide --
MS. DROUIN: Well, let me say it's not -- I mean I don't
look at just the ratio.
DR. APOSTOLAKIS: But let's go back to the graded quality
assurance regulatory guide. They don't talk about delta CDF at all
because we all agree that there are no tools for estimating delta CDF
when it comes to quality assurance so the only thing that happens is we
use importance measures to --
MS. DROUIN: But the important measure calculates it has a
ratio. It also calculates it has an interval which is the delta.
DR. APOSTOLAKIS: And I agree with you.
MS. DROUIN: And hopefully people use both of them.
DR. APOSTOLAKIS: And that comes naturally from this, the
last sentence here -- which I deleted at the last moment was that the
absolute value of CDF or delta CDF if you want should play a role in
these decisions, and you agree with me. My point is that right now it
does not play a role because many times we give up. We say we can't
calculate delta CDF. Maybe we shouldn't look at delta CDF but we have
CDF itself, okay, because in other cases for a plant where the core
damage frequency is 10 to the minus 6 and another one is 10 to the minus
4, Fussell-Vesely and RAW still are still the same so presumably the
licensee would have to take the same action in both cases.
MS. DROUIN: I guess I am confused by when you said we can't
do it. I am not aware of any of the computer codes that don't do. I
mean they all calculate the delta, interval.
DR. SHACK: She is saying the delta for the RAW calculation,
not the delta that the graded QA makes the difference. See, you're only
looking at --
DR. APOSTOLAKIS: No, delta CDF she is saying.
DR. SHACK: The delta CDF in terms of the RAW.
MS. DROUIN: -- of the RAW. Right.
If you go and use your same example but calculate your RAW
as the interval, not the ratio --
DR. APOSTOLAKIS: That's fine and I agree that that is the
way it should be done. What I am saying is the regulatory guides as
they are today I don't think they do that.
MS. DROUIN: I don't think the guides differentiate whether
it is a ratio and interval. They just say use the Risk Achievement
Worth, which could be either measure.
DR. APOSTOLAKIS: No. We just put the components into
categories and then take action based on that without looking at the
absolute value or delta CDF and so on. I mean if we did that, then this
problem would not be there, I agree. I fully agree. So you just gave
me the answer in other words -- yes, I agree.
I didn't -- I think the only message here is that we cannot
make decisions using these measures only, I think, okay? Now there may
be other implications but it's probably too soon to tell.
Now we can proceed with Mr. Matthews --
MR. NEWBERRY: Mr. Newberry.
DR. APOSTOLAKIS: Okay -- Mr. Newberry. Please identify
yourselves.
MR. NEWBERRY: I am pinch-hitting for Mr. Matthews.
DR. APOSTOLAKIS: Okay.
MR. NEWBERRY: Good morning, Mr. Chairmen and committees.
We are glad to be here. I am Scott Newberry -- I am Dave Matthews'
Deputy -- and we'll open our presentation here. For such an
overwhelming project there is no way I could do this alone. We have a
team of folks working on this and I am going to introduce them in a
minute.
Dr. Apostolakis talked about importance measures. Mike
Cheok will be getting into that aspect of categorization a bit in the
presentation. I just jotted down some reactions. One -- I think it is
critical that we have an understanding of importance measures because
it's one aspect of what we're trying to do here certainly. Mike will
talk about that but I know in the NEI proposal, which Adrian may talk
about later, they talk about a blended approach and I think perhaps
there's an appreciation of some of the difficulties here, but in Option
2, which we are going to be talking about today, the design basis will
stay the same. The Option 3 approach, which Tom King will talk about
later today, I think will look at the possibility of changing the design
of the plant, the design basis of the plant. Here we are talking about
grading the treatment on systems, structures and components.
But I think most importantly we have to have that
understanding if we are going to have an effective rule.
DR. APOSTOLAKIS: Again, and please don't misunderstand the
purpose of my little talk there. It's really to look at -- I mean there
is a wonderful paper that is out there written by I believe Mike, Rick,
Sherry, but this is kind of different here.
I think we need to explore a little bit better the
significance of these measures and make sure that we and the expert
panel know some of the implications.
For example, I don't know if the expert panel can say, yes,
on the basis of the risk measures we should do this to this component
but because the core damage frequency is so low already we are not going
to do it.
MR. NEWBERRY: Right.
DR. APOSTOLAKIS: I don't know. Maybe they should be able
to say that, so don't misunderstand what I just said. I didn't present
it as a fatal flow in what we're doing. It's just that we need to get
more into it.
MR. NEWBERRY: Thank you. I am going to do the first
viewgraphs, which basically are to touch on items in the agenda and then
get into some of the objectives of the rulemaking.
To my right is Tom Bergman, and Tom is really the lead
Project Manager on the effort. He will do most of the briefing. Tim
Reed, to his right, will be keeping him out of trouble with flipping
viewgraphs and answering questions, and Mike Cheok will get into the
importance and categorization aspects as we get into the presentation.
Just to give you a feel for where we are on this, we sent
you a big package to help on this meeting. The package, frankly, is
still a bit fluid. It is just going into the office concurrence process
here, but I did feel comfortable sending it to you. I think it lays out
the issues, challenges and the concepts that we feel that we need to get
to the Commission so we can get out and get comment on those things.
That is where we are in the process right now is the need for comment
including the input from the committee, so we do have a plan and that is
what we will be talking about today.
I think we're certainly well enough along to talk about what
the major tasks and issues are and we will go through some of those, and
also the timing -- the timing here is important. When do you grant an
exemption? You may have questions on the exemption process or the pilot
process, how they fit together with proceeding to proposed and final
rule.
We can talk about that largely based on the last meeting,
where we got comment from the committee on how you select rules, and Tom
will get into which rules we think can be affected here, those that
might not be affected, and we, like I said, based on some comments from
the committee, we worked hard to come up with criteria to apply to our
review of the rules and we will talk about that a little bit.
It is a complicated project. When you see the list of rules
that we are talking about touching upon, you start worrying about the
relationships and unintended consequences of changes you could make. We
are struggling with some of those issues. When you start talking about
50.59, you start talking about 50.36 -- the tech spec rule -- and you
really start struggling when you look at the relationships of a
deterministic regulation and risk informed regulation and the roles of
those rules, and we will talk about that today a little bit.
I think somewhere out there in the audience we have an
attorney. Janice is in the back. If we get into process issues, OGC is
here to keep us honest, but I think before we get going the objective
today I think is to impart understanding to the committee. We don't
have answers to all the questions ourselves -- I will tell you that
right upfront -- but maybe we can at least figure out what the questions
are. I think in this project that's the objective and we look forward
to the input from the committee so we can move on. Tom? Oh, wait --
I've got the next viewgraph, don't I?
I insisted we put this in here to talk about what we are
trying to do. When we got ready for the brief, I didn't think we were
really doing that, so we are trying to set up an alternative approach
that a licensee could voluntarily select to categorize or risk inform
the treatment requirements. "Treatment" is a term that we do attempt to
define in the rulemaking plan, and we'll talk a bit about it today, but
it is really the investment that a utility makes to grant the highest
level of assurance in the regulatory process to equipment.
It is derived largely today by the term "safety-related" --
that is the highest treatment, the special treatment, and the intent
here would be to relax treatment in areas where the equipment is of low
importance -- low importance, lower significance.
The second bullet there is a listing of our primary
performance measures in all of our projects -- I mean they are found in
the strategic plan and we're working to define them, but here we are
really, as I said, we're not changing the design of the plant, but we
need to maintain safety as we look to see what programs or what
equipment we will focus on and retain the special treatment that reduce
burden on equipment, a large set of equipment where we think the
importance is lower, and I think, as was proposed in 98-300, the process
would include a testing of the process through pilot plants -- we will
talk about that a little bit and as we have gotten into the projects we
see that as a necessary step before the agency would proceed with the
final rulemaking, and we will talk about the pilot plant project.
So with that --
DR. APOSTOLAKIS: Scott --
MR. NEWBERRY: Yes.
DR. APOSTOLAKIS: -- the second bullet there I think needs
rewording because if you reduce unnecessary burden and you improve staff
efficiency and effectiveness it is quite likely you are actually
increasing, enhancing safety, because you are freeing resources that may
be used. I think what you mean is maintained just at what you are
doing, but then these other things will actually have a positive impact.
MR. NEWBERRY: I share that view. I think as a standard or
a minimum, a minimum standard would be to maintain safety, but as we
proceed here, I think that will certainly be a hope, if we could improve
efficiency and reduce burden and focus our resources and attention on
the higher significance equipment I think we would be enhancing safety.
Is it your comment that that should be the objective, to
enhance safety?
DR. APOSTOLAKIS: I think it is more of a statement of fact.
It is not an objective. If you make it risk informed --
MR. NEWBERRY: No --
DR. APOSTOLAKIS: -- yes, it should be the objective.
You start out with the objective of maintaining safety but
then because of these other benefits you may end up actually enhancing
it. Somehow that has to come across. It's just a comment.
MR. NEWBERRY: Thank you for the comment. I share the view
and we'll see if we can do that. Tom.
MR. REED: Good morning. Just quickly, you are pretty
familiar with the background.
This effort was initiated in SECY 98-300, described as
Option 2. The Staff Requirements Memorandum dated June 8th approved the
approach and gave us a due date on the rulemaking plan of October 31st.
As you have been provided, we do have a draft paper and all the
attachments and we are currently on schedule to meet that due date.
This next slide is done to show how the difference from what
we are proposing to do from what is traditionally been done. The
traditional approach has divided the components into safety-related and
non-safety-related. Now we will also do it on the basis of safety
significance, by segregating those of high safety significance and those
of low safety significance. The result of that is you get four regions
of components, those that are safety-related and high safety
significant, those that are non-safety-related and high safety
significant, and those that are safety-related of low safety
significance and non-safety-related of low safety significance.
DR. APOSTOLAKIS: So this new system then will preserve the
definitions of safety-related and so on? You are not replacing them?
MR. REED: Right, we are not replacing them. First, from a
rulemaking standpoint we thought that would be too difficult to do
within the current rules both in terms of since we are expecting
voluntary implementation it would become very confusing to have safety-
related mean different things depending on the licensee and the specific
rule, and second, simply replacing the term "safety-related" with "high
safety significant" would not work alone in changing some of the rules,
because they say the scope of this rule is safety-related and other
things, so we felt it was best to bring in new terminology.
This also helps us maintain the current design basis because
you can still refer to safety-related which links you to that design
basis.
DR. KRESS: Now when you say "safety significant" you have
something in mind other than just effect on risk? You have other
things --
MR. REED: That is correct. It would be a risk-informed
process but it is not a risk based process.
DR. APOSTOLAKIS: Now --
MR. NEWBERRY: I think it would be good to leave this up
here awhile so the committee is at least comfortable with these regions
as we proceed, so if you have any questions we can talk about them now.
DR. KRESS: Well, any time you have a sharp boundary --
MR. BERGMAN: We are not implying a sharp boundary.
DR. KRESS: Well, if you did have a sharp boundary you would
want it set at a level that you felt was conservative.
MR. BERGMAN: Yes.
DR. KRESS: Or you could have a gray boundary which would
be -- amount to the same thing.
DR. APOSTOLAKIS: That's different.
MR. BERGMAN: Well, what we are doing within this approach
is within Regions one, two and three will all get treatment. They'll
still be within scope of the regulations, okay? Region one currently
gets a lot of special treatment.
It may need different treatment because the reasons those
components are of high safety significance may not be quite the same
reasons they are safety-related. That is this Issue 4 we address in the
paper, part of it.
In Region two those SSCs are currently non-safety-related.
They will likely need to have some special treatment added to address
the reasons they are of high safety significance.
Region three is where the burden reduction comes into play.
That would be components that are currently safety-related and thus have
a great deal of special treatment but are of low-safety significance and
we expect that we shall be able to reduce the amount of treatment,
however we'll still need some assurance that the components are capable
of performing their functions in response to design basis events,
because that is what is required in Part 50. We are not changing those
design basis requirements.
DR. APOSTOLAKIS: Are you done? I was intrigued by
something in the report that cited several regulations where these
things are defined, so went there. In Part 50.2, safety-related SSCs
are defined as those that must remain functional during and following
design basis to assure the integrity of the reactor coolant pressure
boundary, capability to shut down the reactor, and capability to prevent
or mitigate the consequences of accidents -- and that is repeated in
several other regulations.
Then, as you point out in the report, there is also this
concept of "basic component," which is I guess different. Is it --
because in all cases "basic component" -- this is now from 21.3 --
"includes safety-related design, analysis, inspection, testing,
fabrication, replacement of parts or consulting services."
So a consulting service is a basic component?
MR. BERGMAN: Yes.
MR. REED: Yes.
DR. APOSTOLAKIS: And this is different from safety-related
stuff or is it the same thing?
MR. BERGMAN: That is the principal difference.
MR. REED: Yes. I think basic component goes in a sense, at
least in my view, goes beyond what you think in terms of safety-related.
If you read the safety-related definition, that is a
structure, system, component definition --
DR. APOSTOLAKIS: Okay.
MR. REED: -- whereas basic component is any activity
involving those things including calculations, analyses -- anything you
do that meets the basic components. If you are doing an accident
analysis calculation on an SSC that is safety-related, that is a basic
component, that calculation.
DR. APOSTOLAKIS: And there is consistency in fact if you go
to 50.49 -- there is again safety-related and so on, except when you hit
Appendix A. Now we have something new -- components, structures and
systems "important to safety" now. That is SSCs that provide reasonable
assurance that the facility can be operated without undue risk to the
health and safety of the public.
So where does that fit in here? This not safety-related,
right? These are not safety-related, are they?
MR. BERGMAN: Right. The traditional view has been that
important to safety is a broader set of SSCs that safety-related, and
that the equipment that is important to safety varies somewhat with each
regulation.
DR. APOSTOLAKIS: Now why in Appendix A do they feel the
need to refer to those and in the other parts they didn't? Because it
is more recent?
MR. BERGMAN: Is that it?
DR. APOSTOLAKIS: That is what it is? It's more recent?
MS. MOORE: No. Appendix A is not more recent.
DR. APOSTOLAKIS: You have to come to the microphone.
MS. MOORE: Appendix A is not more recent than 50.49.
DR. APOSTOLAKIS: Would you identify yourself, please.
MS. MOORE: Yes. My name is Janice Moore, with the Office
of General Counsel.
DR. APOSTOLAKIS: Okay.
MS. MOORE: But 50.59 is more recent regulation.
DR. APOSTOLAKIS: So I mean is this concept of "important to
safety" similar to the safety significant?
MR. REED: No.
DR. APOSTOLAKIS: No?
MR. REED: Janice will correct me if I am wrong but if you
read through Appendix A, the whole appendix, all those GDCs, by the time
you get to the end you will be completely convinced that "important to
safety" means exactly safety-related.
I mean they thought in terms of design basis, redundancy,
diversity, separation -- you meet all the GDCs, the mentalities, built
throughout that appendix, and in fact if you start looking at other
regulations like take GDC-1, which is quality control, and then go to
Appendix B, you will see that they in a sense equate safety-related to
important to safety, so in a sense the regulations almost equate the two
terms.
There is obviously a lot of argument and, you know, through
the years on what the terms mean. That was one of the reasons why we
didn't want to touch either term and leave them go and start with
something new, some different terminology, if in fact we use new
terminology at all.
As you will see, we are suggesting a new rule without any
defined terminology, so we are staying out of the terminology battles
completely but when I look at that discussion there in the introduction
to Appendix A, the 10 CFR 50, which you just read, there is a very broad
definition. It is almost a perfect definition of what we would like to
say. You know, this is the stuff that is really important, but when you
look at it from a legal standpoint, regulatory standpoint, it starts to
unravel.
DR. APOSTOLAKIS: Well, couldn't this thing be used to
define those high safety significant and say, well, if important to
safety means without undue risk to the health and safety of the public
we have the PRA. We are defining here what is important to safety,
instead of saying we are ignoring it.
Why wouldn't that work?
DR. BONACA: But isn't safety-related really the original
classification --
DR. APOSTOLAKIS: Yes.
DR. BONACA: It came from the FSAR.
DR. APOSTOLAKIS: Yes.
DR. BONACA: And that is why there's many FSARs originally
that have GDCs applicable to them, for example, some plants, okay?
MR. REED: That's correct.
DR. BONACA: So it is a way to provide a definition that is
broader and captures things and that is why we saw for example in the
Oconee application --
DR. APOSTOLAKIS: So what happens now? We are ignoring what
Appendix A says?
MR. REED: No. Oh, no.
MR. BARTON: I don't think we can, George.
MR. REED: Unfortunately we can't.
DR. APOSTOLAKIS: So tell me what we are doing. How is the
safety significant categorization there related to the important to
safety?
MR. NEWBERRY: I think we are going to get to another
viewgraph about how we would approach that.
DR. APOSTOLAKIS: One last point --
MR. NEWBERRY: That is a good question and part of the
struggle we have --
DR. APOSTOLAKIS: One last point. Mike here showed me the
SRM, the SRM dated June 8th, 1999 says Option 2 -- "The Commission has
approved implementation of Option 2 to develop risk informed definitions
for safety-related and important to safety SSCs."
MR. REED: Right.
DR. APOSTOLAKIS: You are not developing risk informed
definitions. You are offering something new.
MR. REED: Absolutely correct.
MR. NEWBERRY: The rulemaking plan talks about alternative
approaches to do what the SRM is asking and the guys will get into this
a little bit.
As we struggled with that, we identified another way to do
this which we think is more effective.
DR. APOSTOLAKIS: Another way? You mean this way?
MR. NEWBERRY: No. He will talk to you about that in a
couple more viewgraphs.
MR. REED: Yes. We can hit that basically a little later
here if you want, but if you look in the rulemaking plan we had three
basic approaches.
One was the redefinition approach which is suggested in the
SRM. Another is a new term approach -- "safety significant" or whatever
it is -- you define that term and use that. The third is a new rule
which doesn't use new terminology. It sits there in Part 50 and
basically says here's all the things you can risk inform, here's the
Appendix you can use to do it, and it separates itself from all these
other problems.
Obviously if you read the rulemaking plan, if you have, you
will see that --
DR. APOSTOLAKIS: Yes -- this is the plan?
MR. REED: Yes, a version of it -- a little bit out of date
in there but --
DR. APOSTOLAKIS: Yes, I have read it.
MR. REED: But we have obviously gone to a new rule. We
think it is the most efficient direction --
MR. NEWBERRY: Let me try one other point. Please
envision -- step back -- 103 reactors here with a voluntary effort,
whether they could come in -- one plant could come in and even on there
is another issued called selective implementation where you could have a
plant, we think, with the standard set of definitions which Mario talked
about in their FSAR for some systems, but then they could come in and
apply for some equipment the alternative regulation here and you could
have both sets of definitions working.
So if you were to redefine the standard definitions here, we
saw a complexity that was unnecessary and the guys came up with what we
think could be a more efficient way to allow a plant to apply even in
subsets of equipment depending on burden -- you know, costs and
benefits -- this new alternative approach which gets around some of
these complexities.
MR. REED: George, basically what we were trying to do was
identify an approach that basically did three things. One, you had to
identify all the rules containing special treatment requirements
somehow, okay, and then you basically had to make a reference to an
Appendix, okay, that says here's the requirements and the methodology on
how you do the categorization, all right, and then there was one more
problem and why this third approach I think comes out to be the best is
we had addressed the two technical issues here that are depicted on the
four-box figure, we call it.
One, this issue of the safety-related, high safety
significance, what you thought was high safety significant in the past
and now you do a risk informed evaluation and you determine (a) it is
not really safety significant but you want to maintain functionality.
That is the one technical issues. How do you do that
without assurance, how are you maintaining functionality without
assurance? That is one technical issue we needed to build into this
somehow or address somehow.
The other issue that we needed to address is how about the
things that come in, the non-safety-related stuff which are important
for events that are beyond the design basis of the facility and now you
are saying, hey, these things are safety significant -- I want to apply
some sort of regulatory treatment to them, but remember Part 50, the
regulations, only mean things for design basis events in general, okay?
So when you bring it in, if you just scoped it in, you would
have no requirements on this equipment, so we had to do something to
address that situation and to address this functionality situation. As
you will see in a little bit, we think the new rule approach does all
those things better than the other two.
DR. APOSTOLAKIS: Now --
MR. REED: Granted we haven't completely --
MR. BERGMAN: If it were mandatory, a mandatory rule for all
licensees, a lot of the complexity with redefining safety-related and
important to safety would go away. You would still have some of these
issues of how would the rules work, but it is not mandatory and it just
becomes too complex.
DR. APOSTOLAKIS: I went back to Scott's slide that says
that the regulatory framework that implements this alternative should
enhance public confidence.
How much are we contributing to the enhancement of public
confidence by Box 2? Box 2 shakes public confidence, in my opinion.
You have non-safety-related equipment for decades and now
you decide that some of them are high safety significant, so is there a
reaction to that? Did we just make a mistake and we are correcting it
now or what?
MR. BERGMAN: No. I think it reflects that we have new
information and where we have determined that in fact those components
are more important licensees need to address that importance.
DR. APOSTOLAKIS: But the words there don't sound good --
non-safety-related yet high safety significant.
MR. BERGMAN: We actually believe that the number of
components to be quite small.
DR. APOSTOLAKIS: These years --
MR. REED: And actually it is also a function of what this
line really means. What is the difference between lower and high?
DR. APOSTOLAKIS: I know, but --
MR. REED: And I am not sure that they are really "high" the
way you are thinking but they certainly aren't low.
DR. APOSTOLAKIS: There is a seminar on risk communication
coming up soon --
MR. REED: Next week --
DR. APOSTOLAKIS: -- maybe this can be used as an example of
what not to do?
DR. SHACK: I mean South Texas had 20 out of 1500 that --
DR. BONACA: That is a fairly small number.
DR. SHACK: That is the kind of fraction we are talking
about.
DR. APOSTOLAKIS: I know, but --
DR. BONACA: And many of them were due to, were related to
recent issues, not the early issues, so there is a learning process too
that brings about awareness of new issues and then identifies some of
this, but I agree with you -- communication --
DR. APOSTOLAKIS: Look at it.
DR. BONACA: I agree with you 100 percent.
DR. APOSTOLAKIS: Take it at face value, really --
DR. BONACA: It doesn't say that at all.
DR. KRESS: When you talk about enhancing public confidence,
you know I hate to get on such an amorphous subject but what public do
you mean?
MR. BERGMAN: The general public.
DR. KRESS: The people out there voting, living around the
plant?
MR. BERGMAN: Even the ones that don't vote.
DR. KRESS: The ones that live around the plant, for
example?
DR. APOSTOLAKIS: Why do you have to say that you will
enhance public confidence and get into these questions?
DR. KRESS: Yes --
MR. NEWBERRY: Let me try that, and I am sure I am not going
to satisfy it, but that's an effort where I think we have got a lot of
growing to do. We are struggling at -- the agency is struggling. It's
a new initiative put into our strategic plan. It just went out for
public comment.
Mr. Riccio I'm sure will have some views on that this
afternoon. You might ask him about the different public stakeholders,
the interest groups, the general public, the industry. We have many
stakeholders that we are trying to reach out to and plan to over the
next year.
I think we are going to be making commitments to even do
surveys and to reach out to get a broader range of views on our
programs. This might be one.
DR. KRESS: I think my point is that we think that's a
laudable objective for NRC. We don't necessarily think it is an
objective of risk informing Part 50.
MR. NEWBERRY: Okay.
DR. KRESS: Take that as just a comment.
MR. NEWBERRY: Okay, thank you.
MR. BERGMAN: As we have already touched on, we are
proposing to create a new rule. It would have the number 50.69 --
DR. APOSTOLAKIS: So let me understand this. We just have
to live with Box 2? There is nothing we can do about it?
MR. BERGMAN: What do you mean, live with it?
DR. APOSTOLAKIS: Non-safety-related high safety
significant -- I mean the message is very bad.
DR. SHACK: Boxes disappear.
DR. KRESS: If there is a box like that, you have to live
with it.
DR. SHACK: If there is a new rule --
DR. APOSTOLAKIS: And I have to put it up there for the
world to see?
DR. KRESS: Well, if you're going to make the rule --
MR. BERGMAN: The goal of our plan is to of course to
explain to the Commission the issues we need to address, and to the
extent there are components in that Region 2 we need to address that
issue.
DR. APOSTOLAKIS: Can you at least use it as an argument
that now you are actually enhancing safety, you are not just maintaining
it?
MR. NEWBERRY: I think where we are going to end up is when
you look at the new 50.69, which doesn't really exist yet, you will see
a regulatory requirement for that box -- with an appropriate treatment,
okay?
There will be a treatment for Box 1, there will be a
treatment for Box 2 and one for Box 3 that we will develop through
comment and --
DR. APOSTOLAKIS: I am not questioning the technical
aspects. I know that you will have that. I am pretty sure you will do
a good job. It's just that the perceptions it creates --
MR. BERGMAN: Yes.
DR. APOSTOLAKIS: -- what I am saying is give it a positive
spin, that you are not maintaining safety you are enhancing it by doing
that. Sorry -- we didn't realize this but now you see? Risk informing
Part 50 we are in fact enhancing safety.
MR. BARTON: This is a voluntary program. If I don't
volunteer for it, I'm not enhancing safety?
DR. APOSTOLAKIS: Because you don't have to. You have
already been found to be under adequate protection.
MS. MOORE: Excuse me, this is Janice Moore from OGC.
I think there are certain pitfalls in making that kind of an
argument. Remember that plants that don't comply with this, there is
adequate protection of the public health and safety, so therefore --
DR. APOSTOLAKIS: I agree.
MS. MOORE: -- your argument would require us to say that
this should be mandatory and I don't believe that we can go there.
DR. APOSTOLAKIS: Can't we say it's an enhancement? It
wouldn't have to be mandatory.
MS. MOORE: I would -- I think that we would have to think
carefully about the ramifications of saying it is an enhancement but it
is voluntary.
MR. BARTON: That's right.
MR. REED: I mean I agree, George. Box 2 clearly
contributes to enhancing the safety of the facility --
DR. APOSTOLAKIS: Everybody concedes that.
MR. REED: -- but Box 2 enhances the safety. You can argue
that Box 3 decreases safety in at least some minimal aspect of safety --
DR. APOSTOLAKIS: I think we have a problem in communication
with Box 2 and the problem is that most of the time you are talking to
engineers --
MR. REED: Yes.
DR. APOSTOLAKIS: -- or your colleagues. Everybody agrees
with Scott -- yes, there will be a place where we will discuss it and
we'll take care of it. But boy, it creates a bad image.
MR. REED: That should probably say in scope or out of
scope --
DR. KRESS: You may recognize a difference in opinion on
this subcommittee. I believe good communication requires you to call a
spade a spade. That is what this box is and I wouldn't worry about you
calling it what it is and to disguise it as something else I think would
be a mistake.
DR. APOSTOLAKIS: Which is related to your earlier question
of what is the public.
DR. KRESS: Yes.
DR. APOSTOLAKIS: If we can't define what is a
subcommittee --
[Laughter.]
DR. BONACA: But it calls again into question the fact that
this is optional. That is an issue that --
DR. KRESS: It could. You know, it is one of those
probability things and I think it is a low probability that that will
ever happen.
DR. APOSTOLAKIS: It's the words. Anyway, let's go on.
MR. NEWBERRY: Good comments. Thank you.
MR. BERGMAN: Okay. So we are proposing this new rule.
Within that rule it will have two basic parts. The first is it will
identify the rules to which this risk informed scope may be applied. It
would be a simple listing of rules.
The second part is that it will provide the treatment
requirements for the equipment within that scope with the three
regions -- Regions 1, 2 and 3. In other words, it may need to modify
the treatment requirements that exist in the rules listed in the first
part. It is not a simple if it is of low safety significance it's
completely out of scope of the rules. We may need to specify what
treatment needs to be retained for those components.
The second part of the rulemaking is Appendix T, which will
provide the criteria for methods that allow licensees to come up with an
acceptable categorization of SSCs.
The goal under Appendix T is to have the criteria be
specific enough such that we can at least minimize the amount of Staff
review of licensees' implementation of the risk informed alternatives.
The schedule is in the paper. I am not going to run through
it. I'd just point out that as far as the South Texas exemption goes,
it will address many of the same issues that we'll need to address in
this rulemaking, so there is a link between the two efforts in terms of
we need them to be consistent and if we can't resolve some of the issues
that could impact the South Texas exemption because we will need to
resolve them through rulemaking, or it could delay the rulemaking --
depends on how it works out.
The second point is that we are trying to get early
stakeholder input by using an advance notice of proposed rulemaking. To
further this, we are holding a public meeting October 13th at which we
will discuss the draft advance notice of proposed rulemaking and the
draft rulemaking plan.
The third point is that, as discussed in 98-300, we believe
that a pilot program in addition to the South Texas exemption is
necessary and we should be able to issue exemptions at the same time we
complete the evaluation of that pilot program, so July, 2001 would be
about the timeframe that the pilot plants would get their exemptions.
We do assume we will be taking the approach of endorsing an
NEI guideline that implements the Appendix T. We hope to receive a
draft of that guideline later this year.
Last, implementation -- if all goes according to the
schedule, implementation for the industry at large would begin in March
of 2002.
One of the efforts we have completed since we last met with
you in July was we developed a methodology for selecting candidate
rules. If you will remember back in July the ACRS in fact suggested
that we come up with a methodology and criteria to provide a better
means of clarifying how the Staff determined which rules belonged in
Option 2.
The first step of that was the scoping review. We went
through 10 CFR identifying those rules, particularly in Part 50, but in
some other parts as well, that use scope such as safety-related,
important to safety, or similar type constructs. That is reflected in
Table 1 in Attachment 3 to the paper. Then we developed five criteria
and the criteria aren't a simple pass/fail. There actually is a logic
that you have to associate with them to determine which rules are within
the scope of this effort. It is pretty simple, a simple diagram.
The first criterion is does the rule include special
treatment requirements. If that is true, then we go down to Criterion
2, which would be will risk informing the rule improve internal
efficiency and effectiveness. If that is true then we said okay, this
is a candidate rule. It doesn't mean that we will necessarily change
the rule. It's just a candidate rule. We are going to look at it in
the proposed rulemaking.
If you answered false to Criterion 2, that it wouldn't
improve internal efficiency and effectiveness, then you go to Criterion
3, and that would be will it reduce unnecessary burden, and the Staff
made a judgment call. We expect industry in particular to comment on
what kind of burden is associated with each of these rules as part of
the ANPR.
Again, if it is true to Criterion 3 it ends up in the scope
of this effort. If you got a false on Criterion 1, in other words it is
not a special treatment rule and there is no burden reduction associated
with it, you get to Criterion 4 and you say will modifying the rule
minimize the need for exemptions or is it necessary to facilitate
rulemaking for another Option 2 rule. Again if the answer to that is
true, it is a candidate rule.
An example of a rule caught by, solely caught by Criterion 4
would be the introduction to Appendix A of Part 50. If you happen to
get a false to Criterion 4, you end up on the last criterion, which is
that changes are necessary to basically ensure the licensing basis is
documented and controlled. Rules caught by that would be 50.34,
50.71(e). If the answer is false to a Criterion 5, then you are --
couldn't fit it all on the page -- you are not -- it is not a candidate
rule.
DR. KRESS: The question I would have about this is there
doesn't seem to be implied in these true and false questions the
quantity, like how much does it improve the efficiency or how much does
it -- is that going to be a component of --
MR. BERGMAN: Yes. That is why they are candidates. In the
proposed rulemaking, the regulatory analysis would address that specific
question -- is the reduction in burden or improvement in efficiency
offset by the cost --
DR. KRESS: It would be like the regulatory analysis cost
benefit --
MR. BERGMAN: Right. Yes, and the ANPR should help us
answer some of those questions, but we do need to address that as part
of the proposed rulemaking.
Mike Cheok is going to explain Appendix T.
MR. CHEOK: Before I get started off, I guess, doing
Appendix T, I would like to address some of George's comments at the
beginning.
I guess we have always been aware that there are
shortcomings to importance measures. I guess the two biggest
shortcomings are that, first of all, it relates only to single SSCs, one
at a time, and the second shortcoming is that it does not relate to a
change in risk. So in all our documents I think we have always said
that the decision criteria is actually the change in risk and the use of
importance measures is just for an initial screening step.
I think when you talk about importance measures we always
forget to say that it is actually relative risk rank, relative risk
importance measures. The "relative" is always left out.
If you have a flat risk profile, even as little as 200
cutsets in a core damage frequency equation, you will always have a
Fussell-Vesely of less than .005, so it doesn't tell you anything. It
is all relative. In your case, George, you have one single cutset, so
you are always talking -- the cutset is always relative to itself, so no
matter what you do to the cutset you are always comparing it to itself.
That is why you get your 1.0.
If you add a second cutset to your example, for example each
contributing equal amounts, and you make improvements to one of the
cutsets, add components to one of the cutsets, then you will see that
the Fussell-Vesely of the one cutset, of the components in the one
cutset, now becomes less because it is now relatively less important
than the second cutset that wasn't improved, so I guess the thing we
need to keep in mind here is that all importance measures tells us is
how important one component is compared to something else in the plant.
DR. APOSTOLAKIS: Well, no. I think you have to go beyond
that.
The Risk Achievement Worth is really a very gross measure --
MR. CHEOK: Yes.
DR. APOSTOLAKIS: -- of sensitivity because, you know, the
unavailability of the component is 10 to the minus 3 or 4, and say well,
let me see what happens if I set it equal to one. See, that is one of
the messages from this, because if you didn't do that, if you went with
a derivative for example, then even in the case of one minimal cutset
you would see that the absolute value of the remaining factors plays a
role --
MR. CHEOK: Right.
DR. APOSTOLAKIS: -- so I fully agree with you, with
everything you said. I mean you justified why these things happen --
MR. CHEOK: Right.
DR. APOSTOLAKIS: -- but this element or this part of the
problem, that the Risk Achievement Worth really results by setting the
unavailabilities equal to one, therefore it is very drastic --
MR. CHEOK: Yes.
DR. APOSTOLAKIS: -- and I am not sure that all the
implications have been really fully understood.
MR. CHEOK: Right.
DR. APOSTOLAKIS: That is all I am saying.
MR. CHEOK: Yes, and I think --
DR. APOSTOLAKIS: But I understand why these things happen.
I mean --
MR. CHEOK: The message I think you are trying to get across
is that we actually will try to go by the change in risk as a
criterion --
DR. APOSTOLAKIS: If we can.
MR. CHEOK: -- use your importance when we can, that's
right, use the importance measures as a guidance.
I mean the Fussell-Vesely actually is a simple measure that
tells you how much an SSC actually contributes to the risk. It is
simple to use and it is additive -- you can add different cutsets.
The Risk Achievement Worth, on the other hand, all it does
is gives you a margin. It tells you how much you can go before you --
when this thing fails. It doesn't tell you anything else except how
much margin you have. In a sense you can judge -- I'm sorry?
DR. APOSTOLAKIS: It doesn't even tell you that.
MR. CHEOK: In the extreme, it fails, you now know how much
your core damage would go to -- the kind of margin you have.
DR. APOSTOLAKIS: Well, that was exactly the point of my
example, that the RAW is always 1 over q independently of how many
additional systems I have, so it doesn't tell me the margin. The margin
is really the conditional probability of failure.
Anyway, again I will repeat what I told Scott. I just
raised this issue as something to think about and the solution may be as
simple as giving some guidance to the expert panel that makes the
decisions.
MR. CHEOK: Okay, sure.
DR. APOSTOLAKIS: I am not asking for a mathematical
resolution to this problem before you go ahead with this, because that
would create big problems, but I think we all should be sensitized to
the fact that these important measures are pretty crude. They are very
crude. They don't follow from the mathematical theory of sensitivity
analysis of various functional forms. They are very crude and easy to
calculate. Maybe it was a trade-off. You never know.
But in your paper, Mike, you did a very good job of
addressing of the issues like the uncertainty there. You have a nice
Figure 7 that I like very much -- the issue of if you take multiple SSCs
out, how do you calculate the measure, the relevant measure, so what I
said is sort of as a complement to that, that there are also other
issues that we have to understand.
For example, people blindly take the average values of the
unavailabilities and calculate all the measures. Now strictly speaking
you shouldn't be doing that. You should first take the average values
of the aleatory part and then integrate as you show in Figure 7, but it
doesn't make much of a difference when the uncertainties are not huge.
Now I don't know how many people know that. Cheok, Parry,
Sherry, and possibility Apostolakis. Do you think many other people are
aware of this? What I am saying is people should become aware of the
limitations and the properties of these measures if they are going to be
used to such extent, because you don't want to have all these regulatory
guides and rules in place and then five years from now a graduate
student someplace says, well, gee, let me see what this means and shakes
up the whole system.
That is all I am saying. I am not asking you to give -- if
you can give a mathematical answer tomorrow that will be great, but I
think it will probably be more along the lines of advice --
MR. CHEOK: Right.
DR. APOSTOLAKIS: -- and, you know, here are some pitfalls,
be aware of them, that kind of thing.
MR. CHEOK: Right.
DR. APOSTOLAKIS: That is all I am saying.
MR. CHEOK: Okay. Appendix T -- the intent for the
Appendix --
DR. APOSTOLAKIS: Let me ask another question. This is a
new subject now, right?
MR. CHEOK: Right.
DR. APOSTOLAKIS: And we have been at it for an hour. Is it
better to take a break now? I hate to have only one break in the
morning. Is this a good time to take a short break or do you guys have
to leave and you want to finish?
MR. NEWBERRY: No, I think we have got a good bit to go in
terms of the categorization and then some of the key issues.
DR. APOSTOLAKIS: Okay, so let's take 15 minutes, until
9:45.
[Recess.]
DR. APOSTOLAKIS: Okay. Shall we continue? Did you bring
your paper down, Mike?
MR. CHEOK: I did, and they are making copies.
DR. APOSTOLAKIS: To be reproduced, okay -- for everyone or
just for two or three select people?
MR. CHEOK: They made 10 copies.
DR. SHACK: They distributed that paper before.
DR. APOSTOLAKIS: Yes. I made sure we had it. Okay.
Appendix T.
MR. CHEOK: The intent of Appendix T was to establish
minimum requirements for the categorization process and to set some
decision criteria for use when you categorize SSCs as high safety
significant or low safety significant.
The intent here is that if a licensee uses this process,
then there will be minimal NRC review. The process in Appendix T is
consistent with Reg Guide 1.174 and SRP Chapter 19 --
DR. APOSTOLAKIS: Let me ask about this NRC review. I want
to understand it a little better. It says here in Attachment 1 that the
burden is less for both the Staff and industry following a no prior
approval appendix approach. Now can you tell us a little about that?
What does it mean, no prior approval?
MR. REED: It's judgment now. What we were looking at is
whether in fact you should have a regulatory process that involves prior
NRC review and approval --
DR. APOSTOLAKIS: Of each licensee?
MR. REED: Right. You know, look at their categorization
method and the like, okay, or whether you should try to build a
framework that doesn't need the prior NRC review and approval. In fact,
in other words have I'll call it an appendix with a box and you stay in
that box and that appendix -- you can go do it and I'll inspect it in
accordance with the new oversight process.
DR. APOSTOLAKIS: So the licensee can come back and say we
have now high safety significant, low safety significant; we followed
your Appendix T?
MR. REED: Yes.
DR. APOSTOLAKIS: So then you will say, okay, then his
categorization has value.
MR. REED: Yes. Right.
DR. APOSTOLAKIS: Without going back and checking each
component.
MR. REED: By the prior NRC review and approval basis --
that's right. We would be inspecting later on, as called for in the
oversight process. That approach, the appendix approach with no prior
review, is assuming we can construct that appendix first of all, that an
appendix that maintains safety, an appendix that also is clear and
unambiguous and can be consistently implemented and that the Staff can
be confident that it can be implemented such that we don't need to
review it -- okay, if we can construct that, then the judgment was that
framework would actually be the least burdensome for all parties and
ultimately then everybody benefits.
DR. APOSTOLAKIS: Yes.
MR. REED: But that remains to be seen, whether we can do
that or not, and so we are kind of hedging on it, as you can tell, if we
can actually accomplish that.
MR. CHEOK: So this process is consistent with Reg Guide
1.174 and SRP Chapter 19 and it is also consistent with the new NRC
Oversight Program and the use of the cornerstones. I guess the Reg
Guide 1.174 requirements, the principles there are to maintain
consistency in a defense-in-depth philosophy, maintain sufficient
margins and in this case, I guess maintain sufficient margins in the
performance characteristics of SSCs such that there is allowance for
uncertainty in SSC performance
We need to maintain adequate public health and safety by
limiting risk increases, if any, to small increments. There will also
be a requirement for performance monitoring measures to ensure the
inputs that we used to justify less requirements for some SSCs remain
valid for the plant life.
The safety significance of SSCs shall be determined as part
of an integrated decision-making process which uses an expert panel and,
as George said earlier, the input from the PRA would then be used as one
input. The expert panel will use engineering and deterministic
information to blend all the information to come up with the final list
of what is high safety significant and what is low safety significant,
and again the PRA will then be used again to try to quantify the change
in risk, given this set of high and low safety significant components.
DR. APOSTOLAKIS: Now if there is an expert panel and there
will be involved in this, it seems to me that going to a no prior
approval mode of operation would be a little bit difficult, because it
is not mathematics anymore. Somehow you have to check whether the
decisions the panel made made sense, right?
MR. CHEOK: And the arguments we actually make is, you know,
we are requiring a lot of PRA standards and everything else, what now do
we require of the expert panel. I think it should be detailed
documentation, basis for the decisions to be kept in the plant site that
could be inspectable.
DR. APOSTOLAKIS: Now I remember some time ago the Staff
told us that eventually there would be a document with guidance to the
expert panels in general. Did such a document ever get produced or
they're still thinking about it?
MR. CHEOK: As far as I know, such a document has not been
produced yet.
DR. APOSTOLAKIS: Right.
MR. CHEOK: So the Appendix does get into some requirements
for the use of the PRA.
For example, for risk metrics we require that you use CDF
and LERF and that when you risk ranking you do it at the component
level.
We do suggest screening criteria for Fussell-Vesely and
RAW -- one of .005 for Fussell-Vesely and 2 for RAW and we suggest that
initially any SSCs that exceed these criteria be ranked as HSSC and then
delivered to the expert panel for more considerations.
I guess we discussed why we asked for risk importance
measures a little earlier -- basically to give the expert panel more
information on the relative worth of these SSCs and what margin they
have if they decide to make changes to these SSCs.
DR. APOSTOLAKIS: So it is -- the process as it is now
relies on the importance measures, not on the absolute value of the CDF
and LERF?
MR. CHEOK: It depends on the importance measures to
identify the SSCs to the expert panel. Once the expert panel comes up
with the list of components to be put in the high safety significant
bin -- in Bin 1 as opposed to Bin 3 for example -- then we do use the
PRA to quantify the change in risk from moving components to Bin 3.
We do run into a problem here in the fact that how do we
credit, how much credit do we give to SSCs in Bin 3 and how much credit
do we give to commercial grade components when we say that something has
to retain its functionality -- what does that mean in terms of
reliability and unavailability.
One part right now is that we do let the -- maybe we can let
the licensees determine a level of assurance, a level of unavailability
and reliability for these SSCs and then they have to assure this level
somehow, either through testing, maintenance or however they feel that
they can do it.
DR. APOSTOLAKIS: Yes. I think there are two pages in
Appendix T that are critical -- 33 and 34. Indeed, on page 34 you say
an assessment of the potential impact of removing SSCs from special
treatment shall be evaluated. Now it seems to me that that evaluation
will have to be more or less qualitative, won't it?
Ideally if we could do this, then the problem I mentioned
earlier today wouldn't be there.
MR. CHEOK: That's right.
DR. APOSTOLAKIS: It goes away.
MR. CHEOK: Right
DR. APOSTOLAKIS: But we do recognize that recategorizing
components -- I mean is something the PRA is not sensitive to these
things.
MR. CHEOK: That's right.
DR. APOSTOLAKIS: And then you go on to say the potential
changes in CDF and LERF shall be estimated by a calculation in which the
failure likelihood of all low safety significant SSCS modelled in the
PRA is increased to levels corresponding to the failure likelihood for
commercial grade equipment.
The problem is we don't have data for this kind of thing,
so --
MR. CHEOK: That's correct.
DR. APOSTOLAKIS: -- so are you asking them to do the
impossible?
MR. CHEOK: No. Like I said earlier, we will be putting
this out for public comment and we will get some comments back on it,
but one possibility --
DR. APOSTOLAKIS: We just got one.
MR. CHEOK: One possibility is for the licensees themselves
to determine what level they think they can keep these SSCs at and then
they have to basically maintain this level. In other words, if they
want to choose a very high unavailability, for example, .1, then when
they do the quantification they might not come under our delta CDF goals
or guidelines.
On the other hand, if they want to choose a real low one, so
that they can come under the delta CDF and LERF guidelines then they
will have to live with it somehow when they do their testing and
monitoring later on. That is one suggestion.
DR. APOSTOLAKIS: I remember in one of our meetings, the
full committee meeting with Office of Research Staff, that we urged them
to do some research to see whether there is any difference in what data
we can collect that will tell us that indeed there is a different
performance of commercial grade equipment compared to the ones under
special treatment, and I don't know whether that ever took place.
MR. NEWBERRY: Can you comment, Tom?
MR. KING: Yes. This is Tom King from the Research Staff.
That is in our FY 2000 budget to go do that.
DR. APOSTOLAKIS: Okay.
MR. KING: So a feasibility study is what we are going to do
so we can at some point in the next fiscal year come back and talk to
the committee about that.
DR. APOSTOLAKIS: Good. So at this point, Mike, my
suggestion would be to go to page 34 and perhaps add a sentence or two
telling the world that the Staff does appreciate the difficulty of
estimating delta CDF and delta LERF and these things, so that people
will not find themselves in bind here, that you are asking them to do
something that nobody including you can do.
MR. CHEOK: Yes.
DR. APOSTOLAKIS: I think that would be a good addition.
By the way -- I'm sorry? Yes, go ahead.
MR. CHEOK: Part of our problem here is that Appendix T is
supposed to be part of 10 CFR Part 50, so as part of rule language I am
not sure what you just said can be construed as rule language.
Actually, a lot of the language here is not rule language. It is Reg
Guide language and so we really have to do something about it.
DR. APOSTOLAKIS: But you say "shall be estimated" -- so you
are allowed to use that in a rule but you are not allowed to say that
this estimation is damn near impossible?
[Laughter.]
DR. APOSTOLAKIS: Just think about the language, because it
really struck me there -- what are they asking them to do? Something
that is really -- since we are on this page, I have a couple more
comments. Is it appropriate to raise them?
MR. CHEOK: Sure.
DR. APOSTOLAKIS: The appropriate time?
MR. CHEOK: Sure.
DR. APOSTOLAKIS: Again, the assessment in changing risk,
you say that the potential impact should be evaluated. Now for all
possible configurations you are asking them to do this?
MR. CHEOK: Yes, we are asking them to evaluate it for
configurations -- if you are talking about external events and low power
and shutdown -- yes, qualitatively if they don't have the PRA models.
DR. APOSTOLAKIS: Online maintenance -- all those different
configurations?
MR. CHEOK: No, I think we're relying more on the average
that that maintenance unavailabilities so it's --
DR. APOSTOLAKIS: But we have had some problems with that.
MR. CHEOK: That's right.
DR. APOSTOLAKIS: And some of my colleagues feel very
strongly that when you take systems or trains out for maintenance --
MR. CHEOK: But I think we have a maintenance rule and tech
spec requirements that would help alleviate that problem.
DR. APOSTOLAKIS: Aren't we finding again ourselves in the
unfortunate situation where somebody follows this, develops these
categories and then when that person goes to the maintenance rule they
will realize that they have to re-do it? I mean I thought that was
NEI's position in the maintenance rule, that you do it once and for all
and then you go with it and this committee disagreed with that.
We said, well, there are certain things you have to do and
make sure that you don't take too many things out.
Now we are coming back to saying, you know, it's really
fuzzy what it means. It just says "an assessment shall be evaluated"
but the issue of configuration it seems to be deserves a discussion
here. Right, Mario?
DR. BONACA: I would agree with that.
DR. APOSTOLAKIS: John?
MR. BARTON: I agree. I think you need some discussion.
MR. CHEOK: Okay, I'll put that down on my notes as
something I need to consider.
DR. APOSTOLAKIS: Yes, and again the discussion should
reflect the fact that we are really not asking people to take, you know,
the thousands of components in a plant and consider all possible
combinations of them being out, because that is a problem that will cost
so much money and it's not worth doing, so somehow we have to bound it
but at the same time make sure that people are sensitive to the fact
that there is concern.
MR. CHEOK: Okay.
DR. APOSTOLAKIS: So that is a little bit of a check.
DR. SHACK: But this ranking wouldn't change what they do
for the maintenance rule, where they have to look at the component out
of service, whether it is risk significant or not?
DR. APOSTOLAKIS: Would it not? I thought the whole
disagreement was that some components that are of low safety
significance during power operations --
DR. SHACK: May change.
DR. APOSTOLAKIS: -- may change and move up under different
conditions.
DR. SHACK: But I thought the maintenance rule captured that
by saying you had to look at what you were taking out of service, that
you couldn't simply bin it that way.
MR. BARTON: Yes, the rule as written, does make you do
that.
DR. BONACA: Right -- a modification we are making.
DR. APOSTOLAKIS: So are you saying then that this rule
should not say anything about that?
DR. SHACK: What this rule says was you'll still have to do
that for the maintenance rule even though you have done this on the
average. When you go to the maintenance rule and are taking things out,
you will still have to --
MR. BARTON: -- to do what the maintenance rule says.
DR. APOSTOLAKIS: But right now it doesn't say that.
DR. SHACK: The maintenance rule unless it changes will
force you to do that.
DR. APOSTOLAKIS: Look, if you look at these two pages here,
there is a discussion on setting screening criteria, Fussell-Vesely
greater than .005, RAW greater than 2 and so if you get into that -- and
then you are asking them to assess the potential impact -- it seems to
me you ought to give people some idea as to what you have in mind and
include this discussion. Maybe the discussion is just when you do the
maintenance rule, you may have to do more -- you know, that kind of
thing -- but in terms of completeness of discussion, it seems to me this
has to reflect that plus the fact that what we are asking them to do is
something that is very difficult to do with the present state of the
art.
Then this will be also an opportunity to say a few words
about how you bound this issue and you don't do, you know, a million and
a half --
DR. SHACK: It sounds a lot like Reg Guide language.
DR. APOSTOLAKIS: Well, that is up to the Staff to decide
what goes here and what goes there. I mean why should the rule have
numerical criteria then? Why doesn't the rule say that for screening
purposes a Fussell-Vesely number should be defined in the Regulatory
Guide that will tell you what it is.
DR. SHACK: The rule probably will say that.
DR. APOSTOLAKIS: Right now it doesn't?
MR. BERGMAN: Right now it doesn't.
DR. APOSTOLAKIS: Now there are a couple more things.
MR. BERGMAN: We generally don't reference Reg Guides and
rule language itself, so we may prefer to actually have specific
criteria here. That is an issue that again needs to be worked out.
DR. APOSTOLAKIS: Now the sensitivity analysis, on page 34,
"The sensitivity of the component risk ranking to uncertainties in the
parameter data value should be evaluated. SSC categorization should not
be overly affected by data uncertainties."
I don't know what that means and I misspoke earlier. It is
Figure 4, not 7, in the paper by Cheok, Parry and Sherry.
There is one correct way for doing, for finding the
importance measures and you guys are addressing that in this section,
and you have a nice picture here -- it is Section 7.1 -- Treatment of
Uncertainties -- and that is to take the average value of the measure.
MR. CHEOK: Right.
DR. APOSTOLAKIS: Not to take the ratio of the average
values. Now that doesn't make any difference as long as the
uncertainties are reasonable -- let's put it that way, the left part of
your figure.
Now if the uncertainties become huge, then the approximate
value you get by dividing the mean values is not quite the same as the
mean value of the overall thing, which is the correct way of doing it,
so as far as I am concerned this is the way to do it, and there is no
need for extra sensitivity.
Because I can see people now saying, well, gee, why don't I
take the failure rates at the 95th percentile level and redo the
importance measures, and now I'm turning the whole thing upside down,
but that's not the idea.
The idea is to treat the uncertainties correctly, and then
again, we know that these measures are just input to the expert panel.
It's not that we're relying on these things, but I think
some sort of reference to how to do it correctly and changing the
language of this paragraph is required, because the issue of
sensitivities -- I mean, from day one, when we were talking about the
draft, you know, 1061, which became 1.174 -- there were words there,
again, that made me uncomfortable, because people can play sensitivity
games and show you, you know, strange results, because we know that the
failure rates have distributions, right?
If I take all of them at the 95th percentile level, I will
get a different categorization.
So, the idea of the importance measures is take the ratio of
the frequencies of the minimum cut-sets, for example, and then average
that ratio over all the epistemic uncertainties.
Now, most people don't do that. They take the averages of
the minimal cut-set frequencies and divide, right?
MR. CHEOK: Right.
DR. APOSTOLAKIS: And your figure 4 shows that this is
reasonable except perhaps when you have huge uncertainties, and I think
this is a great insight and you should take advantage of it, but don't
ask people to do sensitivities, you know, taking into account data
uncertainties, because then you don't know what you're going to get,
plus it's conceptually not quite right.
So, these two pages really are loaded with stuff, and I'm
just offering these comments, okay?
MR. CHEOK: Okay.
Requirements of the PRA -- I guess we are saying that you do
need a PRA, at least a level one, full-power internal events PRA. You
cannot just expert panel everything.
We would like you to consider external risk, external
initiators, and low power and shutdown operating conditions.
If you do not have PRAs for external events or low power and
shutdown operating conditions, you have to address these initiators as
part of the expert panel, and basically, we have some guidance right now
as to how the expert panel can consider these, and in summary, what we
are saying is that the expert panel has to consider that, for each of
these operating conditions and for each initiating event, you have to
assure that there's enough success paths to bring you to a safe shutdown
state that is in HSSC category.
So, you're basically doing a qualitative PRA using insights
from your internal events analysis.
PRA quality -- right now, what we say is that your PRA has
to conform to some consensus PRA standards, and I guess we mean the ASME
standards right now being written, and where you do not conform to these
standards, we would like the licensee to document why they don't conform
to these standards and why this non-conformance does not affect the
results of the categorization and the risk determination process.
DR. APOSTOLAKIS: Now, you are assuming here that this
standard will be blessed by the NRC. Is that correct?
MR. CHEOK: We have a member -- Mary Drouin here is a member
of the standards committee, and I guess eventually it will be blessed or
we will come up with something that -- I'll let Mary address this.
MS. DROVIN: Well, George, we'll either end up addressing it
in toto -- if we do, that's because everything in there is -- we like it
and it meets our needs. Of course, if the standard that is produced by
ASME and phase two by ANS -- if it doesn't meet our needs, then we
would, you know, somehow supplement it and we would endorse it with
exception or addition.
DR. APOSTOLAKIS: Well, that's not what it says right now,
but that's okay. That's a detail.
MR. CHEOK: The next thing is PRA updates.
When the PRA is used for this process, we will require that
this PRA be updated on a frequency similar to what we're doing to the
FSAR nowadays.
These updates become mandatory when plant changes or when
new information comes and invalidates the input that was used to justify
moving SSCs to the LSSC category to begin with.
DR. APOSTOLAKIS: Now, what exactly do you mean by PRA
update? This is a concept of a living PRA?
MR. CHEOK: Living in the sense that we are updating the PRA
with operating data, not one that's -- not a risk monitor-type living
but one that's been updated to reflect plant changes.
DR. APOSTOLAKIS: And the data?
MR. CHEOK: And data.
DR. APOSTOLAKIS: So, in essence, then, indirectly, you are
telling them that they have to do it in a Bayesian way with full
uncertainty analysis, because I don't see how you can do it if you have
a point estimate. Right? Most of the IPs, I understand, are point
estimate, aren't they?
MR. CHEOK: Most of the IPs are point estimates, yeah.
MS. DROVIN: No, they aren't.
DR. APOSTOLAKIS: They aren't?
MS. DROVIN: Most of them did mean -- they just did not
report the values in terms of -- when they gave their CDF, it was a mean
value. They propagated the data uncertainty through the calculation.
DR. APOSTOLAKIS: They did propagate the uncertainty?
MS. DROVIN: Yes, most of them did.
DR. APOSTOLAKIS: Okay. So, it will be easy for them to do
it.
MS. DROVIN: What they didn't do was the modeling
uncertainties.
DR. APOSTOLAKIS: Yeah. But if they did that, then it's
great, because it's easy to go back and update and propagate again.
MS. DROVIN: I wouldn't say every single one, but I would
say the majority of them did do -- did propagate the data uncertainties.
DR. APOSTOLAKIS: Because my impression was that it was
mostly point estimate.
MR. CHEOK: Point estimates was the one that was mostly
reported, but I think the problem that George is -- most people actually
did do the propagation of the uncertainties. The problem is I think the
fidelity of the data gathering to get the distribution to begin with has
not been looked at very closely.
MS. DROVIN: And I would add that's the major point here, is
what Mike has brought up, is where the real concern is.
DR. APOSTOLAKIS: So, if we go to the no prior approval
business again, it seems that there are a lot of subjective judgements
that go into the whole process, even if one follows the process to the
letter, that making a blanket statement that, as long as you follow the
process, everything is okay, is probably not appropriate.
MR. CHEOK: I think the no prior approval thing is one of
the issues that you need to bring up with the public and with the
management and with the Commission.
DR. APOSTOLAKIS: On the other hand, you know, to say that
you will review all these massive changes is probably unrealistic, too,
because you know, it will take you forever.
MR. CHEOK: Right.
DR. APOSTOLAKIS: And I don't know what the best way would
be. I remember vaguely sometime we discussed the possibility of -- or
not the possibility, actually the requirement that the PRA be reviewed
by an independent panel.
MR. CHEOK: That's one of the requirements of the ASME
standards.
DR. APOSTOLAKIS: Okay. And you will have access to the
findings of that panel.
MR. CHEOK: It will be available for the staff to look at.
So, the PRAs can be used as one input to the expert panel.
I think Appendix T lists a list of considerations or guidelines that the
expert panel has to consider on top of what PRA gives them.
Especially when you take into account the cornerstones of
the OSI program, the PRA would give you CDF and LERF insights. We need
to look at things like, if an SSC is required for emergency
preparedness, if the failure of an SSC could affect the functionality of
another high important SSC, the special effects -- that's not well taken
care of, at least not well documented in the PRA, and also things like
exposure, occupational exposure, things like that.
So, we have a list of guidelines for the expert panel to
look at and to rank SSCs either as high or low according to this list.
DR. APOSTOLAKIS: Is that a list on page 37?
MR. CHEOK: My copy does not compare directly with yours.
Yes, it is. That's the list.
DR. APOSTOLAKIS: I have a couple of comments.
MR. CHEOK: All right.
DR. APOSTOLAKIS: It says, in determining the importance of
SSCs for each of these functions, the following factors should be
considered: (1) safety function being satisfied by SSC operation; (2)
level of redundancy existing at the plant to fulfill the SSC's function.
Why? I mean all that is in the importance measure.
MR. CHEOK: It's also in the PRA, also.
DR. APOSTOLAKIS: Well, the importance measure comes from
the PRA, but the degree of redundancy, the level of redundancy is in the
PRA, and it is reflected on the importance measures.
MR. CHEOK: This list is for all SSCs, and I think if you
can see that an SSC is modeled well in the PRA, I can now actually go
through a lot of these items and say that it's either important or not
important according to what my PRA tells me.
On the other hand, there are SSCs that are not modeled.
DR. APOSTOLAKIS: But maybe you should limit it, then, to
those, because it says requirements of the qualitative assessments.
In other words, the expert panel now has received the input
from the PRA, and now they're beginning their deliberations, and what
you are doing here, you are asking them to go back and look at things
that are already built into the importance measures, and I think -- and
a lot of those guys, I suspect, will have no idea what the importance
measures really represent.
So, they will take it very seriously. Well, gee, look at
the safety function and the level of redundancy, and I think that it
should be clearly stated here that the importance measures represent
this body of knowledge, okay, so the redundancy is there.
Now you have to look at things that are not -- either are
not there or are not treated well.
Like in item six, emergency operating procedure instructions
and so on -- that's typically not in the PRA. So, I would rather have
them look at that, in combination with the importance measures.
Then we go to the next one, and it says for SSCs not modeled
in the PRA. Well, again, don't we have to understand why they are not
modeled? I mean they are not modeled for some reason.
Either they were irrelevant to the scope of the PRA, which
then the expert panel should be informed of -- surely you don't mean
oversights, I mean mistakes.
MR. CHEOK: No. In this sense, I also mean those things
that are implicitly taken into account in the PRA. In other words, we
assume that this one component works -- we assume that room cooling, for
example, works for pump operation to be successful.
DR. APOSTOLAKIS: So, you are really addressing the issue of
the basic assumptions of the PRA, and I think you should state it in
that way, and this is where our earlier comment regarding the different
configurations comes into the picture, because some of those systems
that may become significant under certain configurations may be treated
very cavalierly when the plant is at power.
My colleague, Mr. Barton, is nodding, so I guess that's
true.
So, this is the kind of thing that I would expect to see
here, because this business of SSCs not modeled in the PRA use too much,
and unless you really know what the PRA does, that may be a misleading
statement, to say, oh, gee, the PRA picks up transients, you know, or
they didn't model this or let's do something about it. No, there must
be a reason why it was not modeled.
MR. CHEOK: Okay. I will clarify that list -- those two
lists.
The last two things I'm going to talk about, real quickly,
is that we do require performance monitoring and corrective action.
Again, we'll try to focus the monitoring onto the HSSCs,
because those are the components that actually -- again, since this is
all relative, those are the components that make it so that, you know,
you have LSSCs that are less important.
The last thing I want to talk about is the Appendix T. That
lists the requirements of an expert panel in terms of procedures needed,
the training needed, the expertise, membership, and the decision
criteria.
That's all I have.
DR. APOSTOLAKIS: This no prior approval -- 50.59 is part of
this, right?
MR. BERGMAN: To a limited extent. We're actually proposing
at this time that we would not change the scope of 50.59 per se but,
rather, the change in special treatment would not be subject to 50.59,
but you could not change the functional capabilities of the SSC without
going through 50.59.
So, it's different from the other rules in this effort in
that respect.
DR. APOSTOLAKIS: Okay. I'll have to think about that.
MR. NEWBERRY: You were getting at the point with respect to
prior review and approval, weren't you?
DR. APOSTOLAKIS: Yeah. I'm trying to see whether our
actions are consistent, self-consistent. We may have minimal, let's
say, not prior, but minimal prior approval for these kinds of things,
but then if someone wants to make a small change and claims it's under
50.59, we may say no.
So, is it overkill, really, in the 50.59 area and here we're
too liberal? I don't know. I have to think about that.
MR. BERGMAN: Well, I think, in terms of reduction of
treatment, we're being very consistent in this whole effort.
DR. APOSTOLAKIS: But it's the cross-consistency.
MR. BERGMAN: Right. The fact that they're, quote, "out of
scope" of these treatment rules doesn't take them out of scope of the
regulations.
DR. APOSTOLAKIS: Okay.
MR. REED: Right now we view that, if you comply with this
50.69 and Appendix T, that that's essentially redundant to 50.59 for the
special treatment.
DR. APOSTOLAKIS: So, this has already changed.
MR. BERGMAN: It is a living document, yes.
The last slide is the issues, most of which we've already
discussed.
Selective implementation was addressed in 9300, and there's
two aspects to selective implementation. One is do you need to do every
rule in the effort or can you just do subsets of them, and our approach
is implying that, in fact, yes, you can do subsets of the rules.
There may be constraints on -- you need to do enough such
that we don't have to issue any exemptions, but you may not have to do
every single rule in there.
The other one is do you need to categorize every SSC in the
plant or can you do only a portion of the plant, and we're undecided on
that yet.
The effect on other regulations -- I mean 98-300 said Part
50. We have, in fact, found that these changes will affect rules
outside of Part 50. We have identified some parts where it's clear
we're going to need to consider that impact, and there is sort of an
iterative effort in there.
As we more clearly define the change to each rule, we may
identify others.
Staff review requirement -- we've already discussed how much
will we need to do.
The South Texas exemption may give us some insights on what
it's going to take for the staff to agree to this.
And the last was actually talked about in the box. The box
slide is the identification and control of the treatment attributes for
Regions I, II, and III.
DR. APOSTOLAKIS: Very good.
So, risk information here means essentially importance
measures, right, Mike?
So, I think a good discussion of importance measures would
be appropriate here.
Anything else that anybody -- I'm sorry. Scott?
MR. NEWBERRY: I was just going to tell you -- I mean, as
late as yesterday, Gary and his staff are struggling with Appendix T. I
think that's fair to tell the committee, and changes are being made.
I mean they're weighing these issues, you know. To minimize
staff review, that means a real detailed appendix, perhaps unlike
anything we have ever seen, or do you want to go into the regulatory
guideline? And so, we're struggling with that.
The comments today shed light on it for us, and I think
we're going to need a lot of comment, and we'll have more discussions
with the committee on Appendix T.
DR. APOSTOLAKIS: Good.
DR. SHACK: This last bullet is one that puzzles me. Does
that somehow mean you're going to have to rewrite every one of these
rules?
MR. BERGMAN: No.
MR. REED: Good question.
MR. BERGMAN: Yeah, it is a very good question. We're
hoping we can -- yeah, put up the boxes chart again -- that it can be a
relatively simple statement.
For example, in Region II, the current non-safety-related
but high safety-significant SSCs -- they need to apply the treatment
rules to the extent that they are addressing those attributes that make
them safety significant and only those attributes in terms of additional
assurance.
We don't want to rewrite 20 rules in 50.69, and as we go in,
we've got to balance how much of that occurs, and at some point, it may
be smarter to create separate rules.
DR. SHACK: Okay. So, it's this language that you're going
to use that tells you how much of the special treatment you're going to
have to give to this component, then.
MR. BERGMAN: Right.
DR. SHACK: That's going to be fun.
MR. REED: Well, yeah. In box 2, I don't like to use the
words "special treatment," but I like to think of it in terms of
maintaining the assumptions in the PRA, for whatever it is, you know,
availability and reliability assumptions in there.
What do you have to do to maintain and make sure that those
assumptions are valid? Remember, these things are coming in -- they're
outside the design basis. You're going to see them because they're in
the PRA.
You're going to say, okay, I knew I had this risk stuff over
here, now I'm defining it a lot better, I know where it's coming from,
and basically, I'm saying, for this stuff, I want to make sure the
assumptions remain valid, and I've got to do something to maintain that.
That's how I view that.
MR. NEWBERRY: The issue applies to all three boxes that
would be in the scope of 50.69.
DR. SHACK: That last bullet's a killer.
MR. NEWBERRY: We'll look for significant issues in Appendix
T and the issue you just brought up, Bill. They're both significant.
DR. APOSTOLAKIS: It was a mistake to put it back up.
MR. NEWBERRY: I knew it.
MR. REED: Just one of many, I think.
DR. APOSTOLAKIS: I don't recall, from reading this
document, what you plan to do to the special treatment components
depending on the box they are in. Did you tell us that and I missed it?
MR. BERGMAN: That was a late development in the paper that
occurred since we sent it to you.
DR. APOSTOLAKIS: But you did not address it in your
presentation either.
MR. BERGMAN: Only to the extent it was in that issue four,
but it wasn't in detail. Since then, we've developed the concept much
further.
MR. NEWBERRY: At this point, we do not have language to
give you that would be meaningful.
DR. APOSTOLAKIS: I just wanted to make sure that you did
not address it today. So, I didn't miss it.
MR. NEWBERRY: No, we did not.
MR. REED: No, you didn't miss it.
DR. APOSTOLAKIS: So, what's left, then, for us to
understand at some future time, I guess, is what you're going to do with
the boxes.
MR. NEWBERRY: Yes.
MR. REED: Yeah.
DR. APOSTOLAKIS: Any other questions from the members? Any
comments from the public on this presentation?
[No response.]
DR. APOSTOLAKIS: Well, thank you very much, gentlemen.
This was very informative. And when are we going to see you again? At
the full committee. Shall we decide what they're going to talk about?
How much time do they have next week.
MR. MARKLEY: And hour-and-a-half.
DR. APOSTOLAKIS: I guess you have to shorten what you
presented today.
I think perhaps some of the issues related to schedule you
can play down and maybe spend more time on the quantitative input.
Again, I'm not asking you to have answers but just say, you know, this
is what we plan to do.
MR. NEWBERRY: Do you want us to bring our box?
DR. APOSTOLAKIS: The boxes, yeah. Address the issue of
what to do with box 2, and maybe if you have some preliminary thoughts
as to how you plan to change pages 33 and 34 to address some of the
issues we raised today. As far as I'm concerned, you can copy whole
sections from your paper, Mike, and put them in the rule.
Now, I know that somebody will object to that, but that's
the kind of stuff that the expert panel should know. Maybe you can
develop videotapes and audiotapes.
And that's it. I don't have any other comments.
MR. NEWBERRY: Thank you for your comments today.
DR. APOSTOLAKIS: Now, the next presentation is by NEI, but
we will take a break first. Be back in 10 minutes.
[Recess.]
DR. APOSTOLAKIS: Okay. We are back in session.
Now we will hear about the industry activities to support
Part 50 reform.
Please identify yourselves.
MR. BRADLEY: We have Adrian Heymer from NEI. I'm Biff
Bradley from NEI. We also have Parviz Moieni from Southern Cal Edison
San Onofre Station, which is one of our pilot plants, here today.
I'd like to start out by saying I appreciate the
opportunity. We did hear a lot of information from the staff this
morning that we hadn't had the privilege to hear before. So, a lot of
the reaction we can give today doesn't really involve a lot of input
from the rest of the industry.
We can give you our reaction on -- you know, our personal
reactions on some of the things we heard, particularly Appendix T, which
I heard people quoting from ages 35 and 37 and such. We haven't seen
it. We have no clue what's in there.
DR. APOSTOLAKIS: So, our meetings do serve some purpose.
MR. BRADLEY: Right. Clearly, you know, given that Appendix
T is going to delineate the staff's expectations for the essential
elements of this process, it's extremely important that we have an
opportunity to look at that, given that we're charged with writing a
guideline to implement that, so to speak. So, we are coming at this
with a different -- a knowledge base that you guys have that we don't.
MR. BERGMAN: I'd just like to remind people that we are
holding a meeting on the 13th of October to go over these documents, and
we do anticipate releasing them in advance of the meeting to facilitate
discussions.
The other thing I'd just like to say by way of introduction
is, one, we recognize this is very conceptual at this point, and it's
early on, appreciate a lot of the thought the staff's put into it.
I think, in general, our thinking is along the same lines as
the staff. There are a few areas of deltas that we'll talk about here
today.
The other thing is I'd like to acknowledge this is a complex
task, and we've spent the better part of probably six months now with a
lot of industry meetings at both the executive level and the working
level, PRA people and plant people, trying to come to grips with how
this would be done, and it is by no means simple.
There are a lot of complicating factors. Some of the big
ones are the optional nature of the change and also the fact that option
two is proceeding ahead of option three. So, you have a problem where
you're trying to establish a regulatory scope, but all the existing
technical requirements are still in place for some interim period of
time.
You know, clearly, in a perfect world, it would be better if
we could do all this at the same time, but that's one of the
complicating elements that we have to deal with.
Our objective -- I don't think this is much different, maybe
stated slightly differently, but it's pretty much the same objective
that the staff presented.
It is important, I think, from an industry standpoint that
we retain the voluntary and selective nature of the implementation. We
have to recognize that, even under the existing licensing basis, there's
a tremendous various in the way the licensing basis is applied at the
fleet of plants.
Because of that, there is a large spectrum of desires on the
part of the plants and the companies with regard to how they might want
to use this.
Clearly, there will be variability of results after you
apply this, but we have to bear in mind, there is already variability in
the licensing bases, and so, we do need to preserve as much flexibility
as possible through a voluntary and selective approach in order to keep
a large industry interest in this activity.
DR. APOSTOLAKIS: I really wonder how voluntary it's going
to be in the long run.
I mean you know that the staff is requesting authorization
to risk information when the licensee is not using risk information.
So, this idea of a two-tier system -- I'm not sure that will
be there for a long time, but at the beginning, at least, it has to be
voluntary, unless the licensee chooses not to interact with the NRC
anymore.
MR. BRADLEY: We have looked at the issue relative to NRC's
proposed policy to be able to request risk information for licensee
submittals. I think the difference there is those are voluntary changes
to your licensing basis.
Here we're talking about your existing licensing basis, and
I think the concept of mandatory changes to that is a fairly significant
issue with regard to the whole underpinnings of the regulation. I mean
we certainly view this as voluntary.
I just wanted to mention there are what we view as five
elements of the whole regulatory reform effort, and one that didn't
really get mentioned this morning but it is important is the oversight
process is being fundamentally revised, and that's well along.
It's going to be implemented by next year, and it's a real
driver for the additional regulatory reform activities we're talking
about today, because essentially you're going to have an oversight
process that is risk-informed, and it's going to be out of kilter with
the regulatory underpinnings, both the assessment and inspection
process, those things. It is important.
That's a real driver for regulatory reform from the
industry's perspective, is to make sure that we can modify the
regulations so that the oversight process is consistent.
That's been able to proceed more rapidly. It doesn't
require rule-making, and the pace of change there has been pretty
profound.
I'd also like to mention we have existing applications going
on. We're all aware of those. You guys have discussed those in many
meetings in the past.
We don't want to lose the pace of reform we have on those,
in the areas of tech specs, ISI, IST. QA, of course, we know about the
difficulties in implementing that.
We're talking about option two and option three today.
There are also some administrative and process requirements, things such
as reporting requirements that may need to be cleared up, ultimately, to
achieve uniformity of this.
What are the industry's activities? We heard a lot about
what the staff was doing.
One of our major activities that we have underway is to
produce the guideline for categorization and treatment. I guess we
heard a lot today that was new to me with regard to how the staff was
proceeding in this manner, with regard to 50.69 and Appendix T.
I guess, as I understand it, 50.69 would discuss treatment
and Appendix T would discuss the categorization or how you use risk
information to develop the scope.
Our view up to now has been that our guideline would address
both those areas, and I think what we're looking for is to be able to
realize NRC's goal of being able to implement these changes without
substantial advance review and approval following the pilot programs,
and we view that the guideline would have to be at a level that would
enable that, and our view is that the staff would approve that and that,
by using the approved process, licensees should be able to implement
these changes following the pilot programs without advance review.
Again, you know, it's important to us to see, October 13th,
to be able to see what the staff has developed. That's critical to use
being able to produce a guideline.
Our schedule right now is to have that before the staff in
draft by the end of this year. There's quite a bit of work that remains
to be done.
We do have four pilot plants. These represent the four
reactor vendors -- South Texas, San Onofre, ANO-1, and Fermi.
I would like to mention South Texas. As you know, they've
already docketed exemption requests to try to achieve their goal of
implementing their graded QA program.
We view South Texas as not so much an industry pilot, as
more of a test case for the feasibility of being able to make these
changes.
The methods they are using are their own. They may
ultimately be consistent with what the industry as a whole decides to
use, but they've basically chosen to proceed ahead of the pack, and the
remaining pilots will be using the industry guideline and will be trying
to do this in a manner that would reflect a wider industry --
DR. APOSTOLAKIS: Are they using any methods that we are not
aware of? I thought they were relying also on importance measures.
MR. BRADLEY: I think that remains to be seen. In writing
the guideline -- I mean I recognize that the applications that have been
done -- QA, IST, and the maintenance rule -- have all used importance
measures.
We spent a lot of time in the last year on revising A-4 of
the maintenance rule for the configuration assessment, and fairly early
on, we recognized that you couldn't use the existing maintenance rule
risk ranking, risk categorization as a means to develop the scope for
the A-4 assessment because of the problems with the single component at
a time nature of the importance measures.
In writing the guideline, that, I think, is still an open
question with regard to whether it will be purely based on importance
measures.
We are looking more at a delta-CDF kind of concept, similar
to 1.174.
A lot of the discussions this morning are pertinent to the
issues we're looking at, you know. How do you take -- how do you
capture into the delta-CDF the effect of taking things out of regulatory
scope and putting them into commercial scope, and you know, those are
the key issues that we're aiming at, but as I'll talk about later,
basically our approach is very similar to a 1.174 type approach, looking
at the delta-CDF.
I don't view where we're going to end up as just doing --
using importance measures as a risk categorization. I think it will
require more than that, ultimately.
I know the pilots -- some of these pilots have substantial
investments already in doing that -- for instance, San Onofre with IST -
- and this is all still preliminary work in progress.
So, I mean they may have different views and more hope that
they can use those at least -- I'm sure as part of the process, but I
don't view it as purely using risk importance measures to categorize the
scope. I think it will involve more than that.
DR. APOSTOLAKIS: You mean more than just the expert panel,
because the staff is proposing to use more than that. I mean the expert
panel is supposed to bring those extra considerations, I guess.
MR. BRADLEY: I'll talk a little bit more about this as we
go through here.
DR. APOSTOLAKIS: Okay.
MR. BRADLEY: The activities of the pilot plants -- there's
two areas. One is to actually implement the process.
The way the schedule is laid out, we will put the guideline
in front of the NRC staff, and after several months they've had to look
at it, the pilot plants would begin their initial implementation of the
guideline, and that would go on over a period of about a year, I
believe.
Ultimately, the pilots, in 2001, would go forward with the
exemption requests.
There's been a lot of discussion about the scope of the
exemption requests. There's a fairly broad scope of rules that's on the
table here. There have been questions in the meetings we've had about
whether we need pilots for all the regulations that are on the table.
I think, from our standpoint, that's an impractical, given
the large number of regulations and the finite capabilities of the
pilots to do this work on schedule.
In our discussion with the pilots, I think the three
regulations we hear most -- the most interest in in terms of piloting
the process are the maintenance rule, Appendix B, and EQ. Those are
what generally are viewed as very good tests of the applicability of
this, and I guess we'll have further discussions on this whole issue,
but I do view it as a difficult undertaking if it's expected that the
pilots would pilot the entire set of regulations that are on the table.
Another issue is the industry response to the advance notice
of proposed rule-making.
Previously we had been working on a petition for rule-
making.
After further dialogue with the staff and recognition that
the schedule they laid out is aggressive or more so than we could have
achieved through petitioning, we've reconsidered that, and I know
believe that, rather than petitioning for rule-making, we will proceed
along the plan that the staff has laid out.
However, we had already developed the petition, the guts of
it, and our intent would be to use a lot of that material in responding
to the ANPR.
This is just a slightly different way of saying, I think,
what the staff already said about Appendix T, but we view our guideline,
as I mentioned, as the vehicle for implementation, again with the intent
of having a level of detail that would provide that without the need for
NRC advance review, that would be used for both the pilot exemptions and
then ultimately as -- I guess we would view as some type of reference
material in the rule, similar to the way, I guess, the regulatory guide
for the maintenance rule references NUMARC 93-01 as an example.
I guess I would view that, ultimately, the rule and the
implementation guidance would reference our guideline as a means to meet
the rule.
The major elements of our guideline, as we envision it now,
would be as you see here -- existing licensing basis considerations, the
risk-informed evaluation process, and then the issues of treatment.
Let's talk about these one at a time.
This is a very, very simplified process chart for the
guideline. Again, there are more elements. This isn't really a flow
chart but just a summary of the major elements of the guideline, and I
think it's fairly self-evident how this proceeds.
It's not out of kilter with what the staff laid out, but
basically, you do start with the entire population of SSCs in the plant,
and the two issues that have to be considered are the existing licensing
basis -- why is an SSC designated as being in the regulatory scope
today, what put it there, and there need to be some grounds on what you
have to look at in that regard, and then the risk importance evaluation
and then the integrated scoping decision based on the results of those
two evaluations, and the output of that being three categories.
Now, what you see here are different categories in what the
staff laid out, and I'm going to talk about our view of those
categories, and I think it is fundamentally a little different than what
the staff just presented with their two-by-two matrix, so I'll talk
about each of those as we go along here.
The scope of the evaluation would be essentially all the
SSCs in the plant. Clearly, there would have to be some rules on what
the boundary of the plant is, and when you get into risk space, you
start taking credit for things that may not be in the plant boundary --
reliability of the grid or the city water system or the, you know,
combustion turbine down the street or what have you, and there will have
to be some rules on that, but generally what we're talking about is
things within the boundary of the plant. It's similar to the scoping
for the maintenance rule.
We talked about some of the categories. There's probably
others -- safety-related, important to safety, non-safety-related. All
the components in the plant would essentially be looked at.
Now, clearly, there are going to be some systems that can be
screened out. Our method would be a multi-tiered system where we'd be
able to do some type of screening evaluation on a system basis before we
got into a component-by-component evaluation.
It can actually work both ways. You may have some systems
that you know aren't going to be important based on the screening rules.
You could also have systems that you know are important and
that are going to be in the regulated scope, and maybe you don't need to
go through a bunch of risk insights to get to that conclusion, so you
may be able to bypass that step.
Those are just some of the things we've talked about with
the pilot plants.
Ultimately, the pilot plants will be looking at selected
systems. I think our intent there would be to get a broad range of
systems, some of which may bring components into the regulated scope,
some of which take components out of the regulated scope.
I don't know if it's really feasible for the pilots to look
at all the SSCs in the plant on the schedule that's been laid out.
That's something we still have to discuss and agree to with the pilots.
Before I talk about this current licensing basis, I did want
to mention -- I guess, based on what I heard this morning, I would say
there is possibly an area of difference.
The matrix the staff proposed for how these things would be
categorized basically said that all -- everything that's now safety-
related would be retained as safety-related and that you would have two
categories, safety-related and high safety significant, safety-related
low safety significant, and then that you would have non-safety-related
high safety significant and non-safety-related low safety significant.
Again, we were looking at that for the first time. I think
that's fundamentally different from our view or intent of how this would
work.
Our view is that you should be able to remove some of the
currently safety-related components from that category, from the
regulated scope. I think that's a significant point of desirability for
the plants in being able to proceed with this.
As you know now, there's currently a substantial variation
in the number of SSCs that are on the Q list for the various plants,
orders of magnitude variation, and these plants all meet the existing
licensing basis.
To say that a plant that has 100,000 items on their Q list
is going to have to keep all those as safety-related -- I think that
isn't the way we've envisioned this up to now, until the time we saw
that two-by-two box.
I think our view as that you should be able to go in and
apply these methods and that, even for things where you haven't been
able to change the option three regulation, you should be able to show
that a lot of your SSCs that are currently on the Q list don't need to
be maintained as safety-related, and I think the concern is one way to
view what the staff laid out is there is no way to take things out of
scope but there are things being put into scope. It looks like a one-
way gate, the way that was proposed, and maybe I'm reading it wrong.
DR. APOSTOLAKIS: That's not the way I understood it.
I think what the staff told us was that it would create
confusion, plus there may be other legal issues, changing the
terminology from safety-related to safety significant. So, they keep
that terminology and they add this extra thing of significance, but the
net result of all this, which they didn't discuss today, may be the same
as yours.
In other words, you may still be in the safety-related
category but not safety-significant, so there is relaxation in the
special treatment.
So, ultimately, the product may be the same, in other words.
DR. BONACA: Isn't that what the South Texas project is
doing?
MR. BRADLEY: I can't speak to the details of their
exemption request. I guess it wasn't my understanding that they were
going to maintain as safety-related all the SSCs that were -- that they
took out.
DR. BONACA: My understanding was that they were pulling
them out.
MR. BRADLEY: Right.
DR. APOSTOLAKIS: So, the important thing is whether you do
with a matrix or whether you do with a classification.
MR. BRADLEY: These things are really more --
DR. APOSTOLAKIS: If the result is the same, then it doesn't
matter.
MR. BRADLEY: If, in fact, that's true, I think these are
more than just semantics issues, though.
I think, you know, you talked about the confusion aspect of
this, but I think the industry would view the fact that this doesn't
provide you with the opportunity to take things out of the safety-
related category is a potential concern.
DR. KRESS: Are you considering the ones that don't opt to
go with the risk-informed regulation?
MR. BRADLEY: It's more the ones that do.
DR. KRESS: More the ones that do.
MR. BRADLEY: Right.
DR. KRESS: My impression was that that would be an end
result.
MR. BRADLEY: Our view has been -- I guess the staff is
saying you don't need a regulatory definition of safety significant. I
mean up to now our view has been you would establish a regulatory
definition of safety significant and that you would be able to
optionally apply that definition and the set of safety significant SSCs
in lieu of safety-related SSCs for a given regulation and that, to the
extent those overlap, fine, but those things that were no longer safety
significant wouldn't be within the purview of that regulation or would
be subject to commercial treatment.
Now what the staff is saying is no, those will all still be
safety-related.
That's just an issue we'll have to discuss further.
MR. BERGMAN: I think you'll find that what you're calling
commercial T is probably equivalent to Region III, and we're saying, for
Region III, it must maintain its -- meet its functional requirements,
and I think they are very similar at that point.
But the issue of are they properly classified today is
safety-related. You don't need rule-making to fix that. Licensees can
change that designation today. If it's improperly categorized as
safety-related, they can change that classification today.
MR. BRADLEY: That's true, although I think, as the South
Texas experience with graded QA has pointed out, really being able to
extract the real benefit of that change requires the more involved, you
know, treatment with exemptions to the other regulations.
I'm just identifying that as one area, I think, where our
thinking is fundamentally a little different at this time.
With regard to the current licensing basis, we talk about
the process considering traditional engineering methods. I guess our
view is that the one you do that -- essentially, also, you know, it's
the same thing, really. You've got to consider the existing licensing
basis and why is the equipment regulated today.
There's a hierarchy of the licensing basis, regulations, the
implementing guidance for the regulations, orders, tech specs, license
conditions, and then you get down into licensee commitments, letters on
the docket. There's a whole hierarchy of things that evolves, the
regulatory pedigree of some component in the plant, and our view is, in
order to make this process work, that we should be able to truncate the
look at that at the level I show here and that is that you consider the
existing analyses, the regulatory requirements, regulations, and the
implementing documents, that in order to reconsider an SSC you need to
look at all those things and evaluate why it's there now, but in terms
of looking at commitments you made, you know, 10 years ago as a result
of an inspection finding, or an LER or what have you, we don't believe
that that kind of level is necessary.
I guess I didn't really see the CLB element or hear much
discussion of that in the staff's presentation, but it does seem to be
something that comes up in the meetings we have, particularly with the
other branches.
They've spent a -- invested a good part of their life
developing the CLB, and it appears to me that you do need some
understanding up front of the treatment of the CLB to make this work,
because essentially you're developing a new licensing basis.
The risk importance evaluation -- we've already had a lot of
discussion of that today.
We've had considerable discussion of this in the industry,
meetings we've had with the working group and the task force.
In general, the consensus is that the 1.174 approach is a
pretty good way to go.
You know, you have different baseline CDFs and LERFs today.
In the fleet of plants as a whole, we meet the safety goal, but there is
substantial variation plant to plant, and there are questions such as,
well, does a plant with a low CDF get more wiggle room in this
transition than a plant with a higher CDF, and there's issues of that
nature.
Is it relative? Is it absolute? You know, how do you take
all those kind of factors into account?
And basically, I think 1.174 had to tangle with all those
issues in its long evolution, and if you look at the process they have
there with the very small change region and the small change region
where, one, you can basically look at just the delta, and then, if you
go into a larger delta, you do have to take into account your baseline
CDF and LERF.
I think that's a fairly reasonable approach, and I would
view our ultimate approach as being similar to that.
DR. APOSTOLAKIS: Remember, though, that deltas that are
allowed in 1.174 are independent of the present CDF.
MR. BRADLEY: Right. But the capability to go to the larger
delta, the small change delta, is contingent on some demonstration of
your complete baseline CDF.
DR. APOSTOLAKIS: When it comes to relaxing special
treatment requirements, why shouldn't the current CDF and LERF play a
role?
In other words, if I'm already down to 10 to the minus 6,
why should I have to worry too much about these things?
That comes back to my comment at 8:30 that if I add extra
protection systems, my role in Fussel-Vesley are not affected.
So, I'm still asking for all these special treatments when,
in fact, I've spent a lot of money putting extra systems there to
protect me, and that doesn't sound reasonable to me.
A plant that has, you know, redundancy to the level of one
out of three, one out of four, why should they have to have the same QA
requirements as a plant that has the minimum redundancy required and its
core damage frequency is close to 10 to the minus 4?
MR. BRADLEY: That's a very fundamental question, you know,
and if you look at the PSA applications guide, we tried to develop a
sliding scale.
DR. APOSTOLAKIS: I remember that. But in that case, maybe
the argument -- I think it would be easier to make the argument in the
present case, because you're not talking about --
MR. BRADLEY: Part of what drove that is just pragmatism. I
think we believe that, by accepting the existing risk level of the
plants as being adequate protection and then being able to make small
changes around that, that that's something that's achievable in the
fairly near term, where if we start trying to look at the more
fundamental issues of plants with lower CDFs being able to, you know,
make more change, then you get into the issue, well, gee, it's actually
a much larger percentage of their baseline if they're allowed to make
the same level as a higher plant. It works both ways, and it's
complicated, and we're just trying to proceed in a manner that will move
this along.
DR. APOSTOLAKIS: There is nothing sacred about percentages,
though.
MR. RUBIN: Dr. Apostolakis?
DR. APOSTOLAKIS: Yes.
MR. RUBIN: I'm Mark Rubin from the PRA branch, NRR.
If I could add -- sure, the baseline risk is an important
consideration and we're struggling now on how to factor it into the
decision process.
In the draft of Appendix T -- I'm not sure if this was the
one that got modified after 1-T or before -- we were looking at a straw-
man approach to factor total CDF into the allowed impact which helps you
scope the components that you can move out of the regulated class.
DR. APOSTOLAKIS: What page is this?
MR. RUBIN: It's on my page 37, but it's not your page 37.
DR. APOSTOLAKIS: So, it's a different document. The
heading of the subsection?
MR. RUBIN: The heading of the subsection -- it's after the
assessment of change in risk.
DR. APOSTOLAKIS: Before the requirements of the PRA.
MR. RUBIN: Yes, sir.
DR. APOSTOLAKIS: In my version, it just repeats what 1.174
says.
MR. RUBIN: In my version, it has different criteria for the
absolute impact or the magnitude of the impact based on what baseline
risk is, and we're trying to arrive at some reasonable way to factor the
concept, because we certainly agree.
DR. APOSTOLAKIS: Okay. That's a good development that you
are thinking about, but it's not in my version.
MR. RUBIN: Sorry about that. It changes every two minutes.
MR. BERGMAN: Are you referring to the statement plans with
the baseline CDFs 1E to the minus 4, etcetera?
MR. RUBIN: That's correct.
MR. BERGMAN: That should be in your version.
DR. SHACK: We have two criteria. We have a 1E -- you know,
an E minus 5 and an E minus 4 distinction.
DR. APOSTOLAKIS: Page 34, you say?
DR. SHACK: Yeah.
DR. APOSTOLAKIS: Yeah, but this is just what 1.174
requires. But Mark is saying now they're going beyond that. In 1.174,
the only place where the CDF plays a role is at the goal level, where
Region I is increased, expanded.
But I think what Biff and I are talking about here is that,
when you are actually making the decision, using your matrix, for
example, two-by-two matrix, it should not be only the important measures
or the delta-CDF, delta-LERF.
Another approach might be to say the absolute value of CDF
and LERF plays a role, that for a plant that has very low values
already, maybe we should be more lenient, because they already have
other built-in protective measures. That's essentially what we're
saying.
MR. BRADLEY: Right. How do you consider all those things?
DR. APOSTOLAKIS: So, it's a slightly different version.
MR. CHEOK: When I was talking earlier about letting the
licensee determine the un-availabilities and reliabilities of the SSCs,
that's what I'm kind of referring to.
If you only have three trains, you can claim less credit for
your LSSCs. Thereby, your delta risk might be a little larger than you
would if you had only two trains.
DR. APOSTOLAKIS: Which equivalently means look at the
absolute value of the CDF, because then, if you do it on a train-by-
train basis, it's going to be huge, because now they can look at
individual systems and use the absolute value of the unavailability of
the system as a basis of decision which will make it, you know, an extra
three volumes, perhaps. But if there is no prior approval, who cares?
This is really an important issue, I think, because you may
want to do that. You may want to do that, to look at the individual
systems, rather than the total CDF.
MR. CHEOK: Right. I agree.
DR. APOSTOLAKIS: Or at least part of the contribution to
CDF, because let's say the CDF is driven, as it very often is, by
seismic considerations, okay? So, you have the seismic risk there
representing, you know, 50 percent or more, or 60 or 70 percent of CDF,
and then you are struggling with the internal events analysis, which is
completely dominated by the seismic risk.
Should you really be using the absolute value of the CDF
which is really seismic risk to make decisions on the internal event
analysis? You may want to use only the results of the internal event
analysis.
So, this is something that I think deserves some
consideration.
MR. BRADLEY: One of the practical aspects that led us to
propose more of a delta kind of approach is that, if you are looking at
absolute values, you get into the completeness issue, you know, internal
plus external plus shutdown and low power, which most plants today
aren't in a position to really profess a baseline CDF that's inclusive
of all the things that need to be in there. So, for pragmatic
considerations, we think that a delta approach is more feasible right
now.
I might note that you mentioned seismic. I think that, if
you look at the areas where difficulties could crop up as we move along
here, seismic and fire are areas that are prone to more uncertainty, you
know, for plants that do tend to have their profiles dominated by those
kinds of things, how they would proceed given that our -- I think the
staff as well as we believe, you know, the internal event PRA would be
the minimum requirement, how you treat those things even if it's
qualitative is going to be important, and there's a lot of work going on
now in fire, NFPA-805, those kinds of issues that could have an impact
on the ultimate outcome of this effort.
This is pretty much consistent with what the staff said,
that -- and this, in conjunction with the next slide, basically that our
expectation is that you would use a level one internal events PRA with a
simplified kind of LERF -- that's on my next slide, I'm getting ahead --
as a minimum to support this, but to address other elements of the risk
spectrum, you would need to look possibly qualitatively or using semi-
quantitative methods.
Also, we agree that the scope we come up with does have to
address the dynamic plant configuration issue, it can't be a static, you
know, risk characterization using importance measures alone.
Equipment out of service does have an impact on the overall
risk importance, and you have to look at the dynamic plant
configuration.
A lot of these discussions are going on right now in the A-4
rule-making on the maintenance rule, are really ahead of the -- a lot of
what we're doing on A-4 is going to pave the way, I think, for this
process.
As I mentioned, we realized pretty early on that you
couldn't just do importance measures to set the scope of the maintenance
rule, and what the maintenance rule applies to, in some ways, you could
argue that other regulations need to apply to, that since you will have
equipment out of service, on-line, or in shutdown in a given plant at
any time, and that has to be factored in.
I already mentioned the first bullet.
One other thing that I don't think the staff mentioned, but
one thing we're looking at in maintenance rule space and that might come
to play here -- the significance determination process which has been
developed for the -- to determine the significance of inspection
findings for the revised oversight and assessment process -- it's
basically a -- I think you guys have seen it.
It's basically what I might call a semi-quantitative method.
It's sort of a de-constructed PRA based just on decades and it looks at
initiating event frequencies, mitigation capability, equipment out of
service, and basically it's a binning kind of approach.
It's cruder than a PRA, but for some of those areas where
you haven't modeled the components in your PRA, we believe a method
similar to this or modeled on this might be a useful approach to allow
plants to proceed with the regulatory scope determination.
So, we are looking in our guideline at some use of the SDP-
type process as part of that overall process, not to supplant the PRA,
but --
DR. KRESS: What does SDP stand for?
MR. BRADLEY: Significance determination process.
DR. APOSTOLAKIS: Is there a document out there we can read?
MR. BRADLEY: Does someone from the staff know where that's
captured? Is it in 99-007? It's SECY 99-007. I'm amazed that the ACRS
hasn't had an opportunity to throw rocks at that yet.
MR. MARKLEY: They have.
MR. BRADLEY: Oh, okay. It's actually a pretty interesting
approach.
DR. APOSTOLAKIS: So, this is not an industry approach.
MR. BRADLEY: No, it's been developed by NRC basically to
categorize the risk significance of inspection findings. You determine
that a piece of equipment has been out of service, you know, for the
last three months, and you become aware of that.
Well, what is the significance of that in inspection space?
It's a risk-informed method that the staff is using, that they are
proposing to use.
The one that's developed now addresses internal events and
power operations. I think they're looking to expand it, but it's an
interesting thing. It deserves a look for this purpose.
We're also proposing that as a screening method for the
maintenance rule A-4 implementation. So, it's getting a lot of play
right now.
I think the scope decision -- this is pretty obvious.
Basically, we also would recommend some type of expert panel approach to
integrate the results of the CLB and risk importance reviews and make
the final scope determination.
We also agree that you'll need a performance monitoring
feedback loop aspect to this. It would be a living process. I don't
think we disagree that you'll need some level of PRA update frequency to
support it once it's in place.
I mentioned the integrated effective change.
I think we talked about this a little bit this morning, you
know, how do you actually come about trying to determine what the
integrated effect of this change is, and this is the whole issue of the
level of commercial-grade equipment performance versus something that's
in the regulated scope.
How do you represent that in some way that you can develop a
number that tells you what the integrated effect of this change is and
allows you to compare it with, say, the acceptance guidelines of a
1.174-type process.
Those would be elements of our guideline and still works in
progress.
I don't think we fundamentally disagree with anything the
staff said there, and we look forward to taking a look at Appendix T to
see what they say in detail.
DR. APOSTOLAKIS: Well, so far, unless I'm wrong, you
haven't really disagreed.
MR. BRADLEY: No.
DR. APOSTOLAKIS: You've just expressed concerns that maybe
the two-by-two matrix will lead to undesirable --
MR. BRADLEY: I think we've --
DR. APOSTOLAKIS: But we don't know.
MR. BRADLEY: Right. The thinking of the staff and the
industry has evolved along similar lines on this thing.
DR. APOSTOLAKIS: So, it's a fair assessment.
MR. BRADLEY: The perspectives aren't that different.
DR. APOSTOLAKIS: Okay.
MR. BRADLEY: Regulatory treatment of SSCs -- a very
important aspect of this whole effort is the regulatory treatment. This
is really where the rubber meets the road and where any benefit to the
industry will actually arise.
You know, we can spend a lot of time developing a perfect
categorization process, but if the output of that is applied and a
treatment is set up, you know, that's where the benefit is.
So, really, in a sense, coming to grips with an
understanding of how these things will be treated that fall into the
various bins is essential and really needs to proceed as quickly as
possible.
I think once the industry has a better understanding of the
treatment aspects, there could be a lot larger buy-in to this effort.
You know, we may have more pilot plants coming forward, be
able to test more regulations, but right now, think there's tremendous
uncertainty about what does it mean when something that was once safety-
related is now, you know, either still safety-related and low safety
significant or is not non-safety significant and you have to rely on
commercial treatment to preserve functionality, and when we have
meetings with the staff, some of the push-back we always get from the
other branches is, well, you have to prove that to me.
It seems to revert right back to where we are now once we
start having that discussion of, you know, give me the paper and prove
to me that what you're doing is equivalent -- what do you mean by
functionality, how do I know you're not going to let it rust away in
place or, you know, all that.
So, these elements are very important, and both the -- I
guess 50.69 and the guideline -- we really -- it's imperative, I think,
that we get an understanding of how the treatment would work.
With regard to the safety significant SSCs that were
formerly safety-related, these things are -- were safety-related and
they're still safety-related, safety significant -- it's conceivable you
could even change the regulatory treatment of those, even though they're
staying in the regulatory envelope.
That's because the process that you've just gone through
should have elucidated the aspects of that SSC that make it important,
and it may be that the way it's being regulated now could be improved
even though it still stays in scope.
So, one of the options we've preserved -- and we're still
talking about that -- is being able to change the way something is
regulated even if it stays in the scope.
So, something that never went out of the safety-related
scope, but is it possible to still improve that based on the insights.
The next category is the things that come into scope.
This is important, very important. This is another issue of
some angst on the part of the industry, and there's a lot of plant-
specific variation here.
South Texas, you know, has done a lot of work in this area.
They are a -- you know, a large dry PWR with three trains, and they
don't see a lot of things coming in -- they see some things coming into
scope.
It's not so clear that that equation will play out the same
way for the whole fleet of plants. If you look at the IPE results and
such, the BWRs, for instance, do tend to find that a lot of currently
non-safety-grade systems are risk important -- feedwater, condensate,
things of that nature, hard pipe vent.
There are a lot of things on a plant-specific basis that may
come into scope, and this is just important as the last one, you know.
What does that mean? I mean there's certainly a -- you know, and the
bounding condition is that means my feedwater system is now procured to
Appendix B, or the condensate system. You know, those kind of things,
those -- I don't think we view that as an acceptable outcome of this.
Now, in a lot of these cases, these are very high-
reliability systems that you have to have to produce power and we've
already spent many years getting the reliability of these systems up,
and we can use performance monitoring-type methods, and I think our view
is, for those types of systems, we can implement performance monitoring
requirements and reliability goals would be our, you know, performance-
based approach, is what we view as the way to regulate these types of
things that come into scope, particularly things like feedwater and
condensate.
Standby systems -- it may be different. You know, if you
have a system where you can't really use a performance-based approach,
you know, how -- what does that mean?
Are we going to have pedigree now for systems that
previously didn't? It's not clear, you know, and that's something we've
got to work with the staff to achieve an understanding on.
This is the commercial T. I guess this is our equivalent of
your bin 3.
We do recognize there's an element of these things that's
going to be in limbo for some interim period of time while the option
three regulations are revised and that you're still going to have
technical requirements that say this is in regulated scope, but your
option two evaluation says it's low safety significant.
What we've talked about in our meetings with the staff is a
licensee commitment or some type of regulatory requirement to maintain
functionality.
Use commercial controls, but it would be a little more than
that. There would be some type of regulatory handle there that says you
will maintain functionality and there's some codification in some manner
of what your commercial controls are.
However, for this category of components, we still believe
you should be able to truncate your CLB and not have to maintain all the
things you may have ever committed to on your docket over the last 20
years or whatever for these things, but you should -- its function is
what we're talking about here.
These are not categorized as safety significant. They're
only there because the pertinent regulations haven't been revised
through option three.
Finally, we have the non-safety significant. Again, there's
been some discussion in our meetings with the staff -- commercial
controls. Basically, we're not suggesting that these items are going to
be removed from the plant.
The question really becomes -- and I guess we've had a lot
of requests from the staff -- describe to us what commercial controls
are, even for these things that are non-safety significant, you know,
how will they be controlled, but the intent here is there wouldn't be
any regulatory requirement to maintain functionality, but there would be
some implicit aspect of this whole process where we would maintain these
as commercial control of these items.
The next slide is just a list of regulations that we've
identified, not that different from the list NRC identified.
We didn't necessarily use the explicit criteria and flow
chart that they did, but the result was very much the same, and if you
look at the list of regulations here -- 50.2, definitions; 50.12,
exemptions; 50.34, FSAR content; 50.36, tech specs; 50.49, EQ; 50.55,
codes and standards; 50.59, the change process, the maintenance rule,
FSAR update.
These are all excellent -- I mean these are the rules that
have an impact on day-to-day operations and are the ones that need to be
reviewed for this program. So, not much disconnect, I think, in our
view and the staff's as to what regulations are on the table here.
Finally, 50.59 -- the staff mentioned their view that the
scope of 50.59 might not need to be addressed.
I guess that remains to be seen in our perspective. Given
that we are potentially making changes to the scope of equipment that
would be under regulatory control, the FSAR is in the current scope of
50.59, whether some of those items are or are not reflected in the FSAR.
I guess I'm not a 50.59 expert. I know there's been a lot
of effort put into 50.59 over the last couple of years, and I think part
of the rationale here is just leave it alone, because no one has the
stomach to go back and try to deal with it again, and there have been
some changes that will be made to it that do make it more palatable for
this application, the questions on the imposition of the minimal
increase kind of words into 50.59.
Adrian, you've had more discussions on this, if there's
something more you want to say.
MR. HEYMER: Our initial developing thought is that perhaps
in 50.69, I think, as the staff called it, you would include a change
process, and that change process would be applied to the risk-informed
regulations or risk-informed activities.
DR. APOSTOLAKIS: So, the risk-informed 50.59 would be in
50.69?
MR. HEYMER: You could call it like that, or you could break
it out and call it something different, but I mean that's one option
that you've got.
DR. APOSTOLAKIS: And what is the advantage of this, that we
are not revisiting 50.59?
MR. HEYMER: It just says that this is the change mechanism
for risk-informed regulations. It deals with the scoping issue that's
on the table and that's being discussed.
It might take a look at the nine questions. We're split at
the moment on whether or not we would just deal with the scope and then
perhaps look at the eight questions later or perhaps deal with the
complete change.
Now, whether it's in 50.69 or it's a separate regulation
within the option B set of requirements, we're still discussing.
We would focus -- at the moment, our thoughts are that we
might focus on the safety functional attribute, how that's impacted,
perhaps use some criteria that might be similar to Reg. Guide 1.174 or
the significance determination process.
DR. APOSTOLAKIS: Risk-inform 50.59?
MR. HEYMER: Yes. We're just thinking along those lines.
DR. APOSTOLAKIS: Every time we say that, you know, people
come back and say, well, yeah, but the vast majority of changes under
50.59 do not affect anything in the PRA.
MR. HEYMER: That's why we say something similar to Reg.
Guide 1.174, but it's also perhaps a process that's very akin to the
significance determination process, and perhaps there's a screening
mechanism up there before that that says are you affecting any safety
functional attribute, does the change affect that, and if it does or
doesn't, then you can go your ways.
That's our just preliminary thoughts on the matter.
DR. APOSTOLAKIS: Can we say that delta-CDF is less than 10
to the minus 6, no prior approval?
MR. BRADLEY: You'd probably have to do something with LERF,
too. I don't think you could just do CDF.
DR. APOSTOLAKIS: And LERF. Okay.
So, we'll have a two-sentence rule that will revolutionize
everything.
MR. REED: This is Tim Reed from the staff. I can't hold
myself back from these 50.59 discussions, but when we were looking at
it, Adrian, you know, we see two difficult issues.
The first one was mentioned. The categorization process,
you know, going from what we had, box 1 to box 3, or your going to
commercial T, I think that's the easier one.
I think that the whole process of the re-categorization, the
expert panel, it basically does the 50.59 job, and there's no need to do
50.59 again. That's the easy one.
But the stuff that comes into scope, these SSCs that come
into scope -- they're coming into scope for reasons that are outside the
design basis, and so, if you try to apply 50.59's criteria to them,
they're meaningless, because 50.59 only means things for design basis
events.
And so, if you brought them in and let's say you put them in
your FSAR and you say 50.59 applies to them, what's that mean?
So, I can understand -- very much understand the problem,
and I don't know if you were thinking this, but when you put it in --
perhaps into 50.69 now, into that regulation, you're only dealing with
things that are coming in from this out-of-scope stuff, and it sorts of
puts in a separate place in the regulations and leaves 50.59 intact for
all the design basis stuff.
I don't know what the criteria are yet. My own mind was, if
you look at it and the plant risk basically stays the same, no prior NRC
review and approval, if the risk goes up maybe you have prior NRC
review. That's a very simple, you know, Tim Reed thought.
That's a big, big effort. It's a very difficult job, and
that would definitely complicate 50.69.
MR. HEYMER: On your first point, we agree, and on the
second point, we were following along the same thought pattern, and
that's why we thought that somewhere in this you need a change process.
DR. APOSTOLAKIS: I think a combination of these things can
risk-inform 50.59 without any problem.
MR. BRADLEY: I think the questions in 50.59, as revised,
may work. I think -- my view, again, personal, but the scope, you know,
of the analyses, the scope that 50.59 covers somehow included the risk-
informed evaluation process you used to scope stuff in -- maybe that
would solve the problem, because the questions could be construed as
being the right ones, you know, and they do have the minimal kind of
language in there that you need to do that.
DR. APOSTOLAKIS: So, this is now an open issue again, risk-
informing 50.59?
MR. BRADLEY: The final slide we have is on schedule --
DR. APOSTOLAKIS: I have to get used to the time-scale of
regulations, you know. I wrote this attachment to the letter in July of
'98. This is September '99 and nothing has happened, but in the time-
scale of regulations, I wrote it yesterday. So, it may still come back.
MR. BRADLEY: I guess the view of most of us the less we
have to mess with 50.59 to make this work, the better off we'll be, just
for the difficulties involved.
We all know from bitter experience how hard it is to weigh
into that regulation. So, if we can adapt what we have to make it work
--
DR. APOSTOLAKIS: I think the industry has taken the point
of view that the scope of 50.59 will remain the same.
That's why they're reluctant to explore other things, and
what I'm saying is we can make it a more powerful tool, you know, just
make it risk-informed, and then a lot of the stuff you have to do now
will really be within, and I think you alluded to that by saying earlier
that the scope has to be revisited.
Okay. Enough on 50.59.
MR. BRADLEY: I think the schedule the NRC staff has laid
out is very aggressive, and the industry will do what we can to support
that schedule.
The guideline -- our schedule is to have that guideline done
by the end of this year, pilots submit exemptions the middle part of
next year, get the exemptions granted the middle part of 2001, and then
optimistically, we'd look at industry-wide implementation of option 2
being about two-and-a-half years off.
It's very aggressive. This is a large animal we're trying
to tackle here, and somehow -- I think, if you look at the prototypes
for what we want to do, where we've been able to go on the assessment
and oversight process is a great prototype to follow here.
We've laid a lot of the groundwork, you know, through the
applications -- ISI, IST, QA. We've had a lot of those discussions, and
now we can build on that and look at the process we use to get quick
results in the assessment process and try not to reinvent all the issues
that we've, you know, consternated over and all this evolution to get to
this point.
We need to be able to rapidly move forward to make this
work. So, the schedule -- we were pleased with the schedule the staff
laid out, and well do everything we can to support that.
DR. APOSTOLAKIS: Would you like to say anything else?
I see Dr. Moieni here. What is SCE doing? Are you one of
the pilots?
DR. MOIENI: Yes.
DR. APOSTOLAKIS: Are you following a different approach
from that of STP? Are you doing similar things? Or you don't know?
DR. MOIENI: We are hoping that, basically, as Biff said,
the guideline -- the NEI guideline document would not be much different
from other risk-informed IST submittal that we submitted last year,
December '98, or even from South Texas projects graded QA.
So, it may have some basically new elements, but the essence
would be similar, so we are going to follow that.
DR. APOSTOLAKIS: Are you helping NEI write this?
DR. MOIENI: Yes, a task force.
DR. APOSTOLAKIS: And South Texas also is helping you.
MR. HEYMER: We've got a group within the industry, South
Texas, San Onofre, all the pilot plants plus a few others that represent
probably about 50 percent of the industry now to help us write this
guideline, and that's why we're interested in seeing the staff's paper,
because then we can perhaps refine it to meet a schedule for submitting
it by the end of the year.
DR. MOIENI: One of the things that we are -- and I think
other pilots are really looking for is the South Texas project
exemptions. This is really key for us. We want to see basically what
happens.
Even though, as Biff said, South Texas project is not a
pilot specifically for this, we really believe it is a good pilot for
this option 2.
Even though there are plant differences, even though the
approaches could be a little bit different from the NEI guideline
document, we still believe they follow similar approach and we are
looking forward to see the exemption request granted by the NRC early
next year and then follow the guidelines document and be a pilot for
option 2.
DR. APOSTOLAKIS: What South Texas is doing is not a pilot
for option 2. Why are they doing it?
MR. BRADLEY: They're doing it to -- as you may recall, they
got approval to implement graded QA. They got constrained by a crazy
quilt of other regulations that prohibited them from doing that. That's
what they're doing.
DR. APOSTOLAKIS: Okay. Anything else you would like to
say?
Any of the members have any comments?
[No response.]
DR. APOSTOLAKIS: Okay. Thank you very much, gentlemen,
appreciate your coming here.
Now, we have to break and come back at one o'clock, because
the schedule is to discuss option 3 at one o'clock, but I would like to
tell my colleagues that I plan to draft a letter -- I think we have to
write a letter, risk-informing Part 50, next week, and the schedule is
already very tight.
We have at least five other letters that are important to
write. So, it would be good to try to put together a draft letter
before Wednesday, and I will need your help.
So, what I'm planning to do is ask you at the end of the
meeting, around three o'clock -- I'll go around the table and you give
me bullets, points that you would like to see in the letter regarding
options 2 and 3.
Now, how many of you will still be here at three o'clock? I
know Dr. Press will not be. Anybody else? And Bob, you will not be?
DR. UHRIG: I will be.
DR. APOSTOLAKIS: Oh, you will be. So, everybody else is
here.
Can you give me a piece of paper with some bullets before
you go, and Tom is doing the same. Unless you want to meet at 12:45 to
discuss these things. Do you want to do that? Is that all right?
Okay.
So, let's say that we will get back together here at 12:45,
and then the staff will begin the presentation at one o'clock. The
formal presentations will start at one o'clock as scheduled. Okay? And
then, for option three, you know, the other guys will be here and will
give you their input.
Thank you very much again. We'll reconvene at 1:00.
[Whereupon, at 11:53 a.m., the meeting was recessed, to
reconvene at 1:00 p.m., this same day.]. A F T E R N O O N S E S S I O N
[1:10 p.m.]
DR. APOSTOLAKIS: Back on the record.
The next presentation is by Mr. King and Ms. Drouin, discussing the
proposed Commission paper and option three, the performance study and
risk-informing the remaining sections of 10 CFR Part 50.
MR. KING: For the record, my name is Tom King. With me is Mary Drouin.
We're both from NRC's Office of Research.
As you recall, SECY 98-300 had several pieces to it. What you heard
about this morning was the piece that dealt with risk-informing the
scope of Part 50 as it relates to special treatment rules.
The complimentary part of that was what are we going to do about the
technical requirements in Part 50, in terms of risk-informing them. And
what the Commission approved us proceeding with was a study of those
technical requirements and coming back to them at the completion of that
study with recommendations on what technical requirements ought to be
changed and what those changes ought to be.
They asked that our plan for doing that study be provided to them for
approval at the end of October. What we sent you yesterday was a draft
of that plan. It's still some work in progress, it still has some
things to be cleaned up, and what our presentation will do this
afternoon is to sort of walk you through what our plan is for doing that
study.
Again, what we're providing is a plan; not a rulemaking plan, but a plan
for doing a study. Therefore, it's a smaller package than you got to
look at for this morning's option two discussion, and, also, being a
plan for doing a study, we don't have to resolve everything at this
point.
There will be a number of things that will come together as we do the
study and implement the plan. So you'll hear some of that today. You
may think some things are a little fuzzy, but that's the nature of
putting the plan together and actually getting in and being able to do
the work.
What I want to do is walk through how we intend to do the study. That
will include the approach, the results of the workshop that we had a
couple of weeks ago, the issues that we're facing, which many of them
are the same issues you heard about this morning. So you will see we've
got a very similar approach as the option two folks have.
Then we'll come in and talk about the schedule and future ACRS
interactions and so forth.
I can skip this. We all know what the three options are in SECY 98-300.
SECY 98-300 also laid out what we called desired characteristics of a
risk-informed Part 50. One of the comments we had gotten from this
committee in putting 98-300 together was what do you want this thing to
look like when you're all done. So we put in the SECY paper, 98-300,
this set of eight items which we really characterize as what we would
like to achieve by risk-informing Part 50.
I'm not going to read them all, but clearly we want to make sure Part 50
now focuses on those things that are most safety-significant, gets rid
of those things that are not safety-significant, are not commensurate
with -- the burden is not commensurate with safety.
We want to be able to accommodate the plant-specific nature of risk. So
there needs to be some provision for allowing plant-specific items to be
factored into this process.
We certainly think doing this will provide a more consistent, coherent
regulatory framework. The plant oversight process is already going
through a risk-informed process. I would expect when we're done with
Part 50, the reactor inspection and oversight program then will be tied
much more closely to what this revised risk-informed Part 50 will look
like.
And then clearly we have the practicality issues associated with risk-
informing Part 50. We believe these criteria will be good when we get
through with the study to come back and look at again to see are the
recommendations we came up with, do they really achieve these eight
factors or how well do they achieve it, and that can be used as a
measure to help us judge were we successful, are the recommendations
we're providing to the Commission consistent with what we're really
trying to achieve. So that's how we intend to use these things.
I just want to, on the next slide, talk about some of the high level
ground rules for doing the study and the approach we're taking. Again,
as in option two, whatever we come up with, if it's implemented in Part
50, it's going to be voluntary on licensees. So we're not talking about
any of this being mandatory.
But when we go in and look at Part 50 and make recommendations, they
could fall in several categories. They could be revising requirements
that are on the books today to better focus on safety.
They could result in adding some new requirements. Maybe there are some
gaps in there that risk assessments say ought to be filled, and this
program would try and fill those or recommend that those be filled. And
they could also end up deleting things, things that are unnecessary or
inconsistent or out of date.
So it could end up really covering any of those three outcomes.
DR. APOSTOLAKIS: So a revision of 50.59 will be under revising a
specific requirement?
MR. KING: 50.59 could fall under here. If you look at the third
bullet, it says we're going to focus on the technical requirements.
We're not going to go in and look so much at process requirements.
Except 50.59, we've had some discussions, it's come up in NRR's
discussions on option two, as to how far do we want to go on 50.59, how
far do you want to go in option two, and how much then would carry over
into option three.
So 50.59 is a candidate for being dealt with under option three. At
this point, I can't really say how far we'll go, but it is on our plate
as something to look at.
The only things at this point that we are going to exclude is the fire
protection regulation, because that's being looked at separately, and
we're not going to go in and try and risk-inform the ASME codes that are
referenced or the IPEEE codes that are referenced in the regulations.
Those will be pretty much givens and we'll try and work around those and
see what else needs to be risk-informed.
We're not starting with a clean sheet of paper. We're taking a look at
what's on the books today and how to change it. The work that you heard
about this morning on risk-informing the scope, the criteria and
approach that was taken there, we would expect to apply a lot of that to
this effort when we get into -- you know, the option two is just
applying it to the special treatment requirements, but I think the
concepts and the criteria and the approach can be equally applied to the
design requirements, as well.
So we would build upon what's being done in option two and apply it to
the design requirements. We're not going to go reinvent something new.
We expect to retain the design basis concept in that I would still
expect, when we're all done, we'll have a set of design basis accidents.
They may not look like the set we have today, but they will be risk-
informed, and I would expect there will be a generic set that would
apply, maybe there will be a set for P's and a set for BWRs, but there
would be a generic set. But then we also need to allow some plant-
specific consideration for unique features or unique initiating events
that may exist at plants.
So there will be a dual set, one generic, one plant-specific, but it
will still be a design basis concept. So what's on the books, a future
plant designer could take it and have some guidance as to how to develop
a future -- apply it to a future design.
We're talking about an approach that makes small changes around the
plant's current risk profile. The Reg Guide 1.174 approach. We're not
trying to use this to drive everybody's core damage frequency down to
some new value or the LERF down to some new value. It will be looking
at the risk profiles that are out there today, which the Commission has
accepted and they meet the adequate protection requirements of the
Atomic Energy Act and so forth, and we're going to look at how can we
make changes around that risk profile that will meet the objectives that
we talked about.
Again, we're only thinking about light water reactors when we do this.
We had some feedback, why don't you make it general enough that HTGRs
could fit in, but we're not doing that. It's LWRs only.
DR. BONACA: I have a question regarding the design basis concept.
MR. KING: Yes.
DR. BONACA: The design basis accidents were really hypothetical
accidents used to design the plants.
MR. KING: Yes.
DR. BONACA: So there is a direct tie between those assumptions and the
structures, systems and components that are in place.
MR. KING: Yes.
DR. BONACA: So I'm trying to understand why you would come with
different sets of design basis accidents now.
MR. KING: Two reasons. One, future plant designers are interested in
what we're doing and this would clearly be of use and of interest to
them, but it also will help existing plants. For example, if the large
break LOCA is no longer the design basis accident has to be analyzed on
a core reload, that you bring in some other LOCA, that impacts operating
plants. So it's that -- it affects both.
DR. BONACA: All right. So there are certain parameters that may be
affected. All right.
MR. RUBIN: If I could add, just very briefly. This was the diesel
example, large break LOCA, as Tom just mentioned, is a really good one
because industry has identified a lot of the design requirements, ten-
second diesel start that had been questioned for a number of years on
the effect on reliability.
I think in the design basis accidents, more likely ones or more risk-
informed might change, for example, having to test the diesel starts,
focus the attention on more likely higher consequence events.
MR. KING: Part of putting this plan together, we had a workshop, as I
mentioned, and Mary is going to talk about that and the outcome from
that workshop.
DR. BONACA: But still you will have a hybrid. I mean, some accidents I
understand you would change. Even for newer plants, you would still
have certain demonstration requirements of some type for your vessel
design, for all those things. So you will have really a hybrid set of
deterministic and probabilistic requirements coming or assumptions in
some of them.
MR. KING: I don't envision the outcome of this to be a total rewrite of
Part 50. I envision it will be selected technical rules that will have
a risk-informed alternative to what's in the books today. Some plants
may not want to take any of them, some may want to pick and choose, some
may take all of them.
Things like vessel, design the vessel to the ASME code, have the
fracture mechanics criteria, the inspection and so forth, that may not
change. We may, as a result of risk assessment, say that stuff still is
valid, it still ought to stay on the books, and we may not be proposing
any change.
DR. BONACA: The reason why I'm asking this is that this is a very
extensive process once you get into that, because you also have to
balance which accident analysis you will change and which one you will
not change, and that brings about a lot of considerations of designs.
MR. KING: Yes.
DR. BONACA: So this is going to slow down that process quite
extensively just because you can't just do it in a day what took however
many years to build.
I'm just asking these questions to understand the timeframe in which
this effort can be developed.
MR. KING: We're going to talk about the time, but, remember, the study
-- the outcome of the study or recommendations to the Commission as to
what rulemakings we ought to pursue, that's not a rulemaking itself. If
the Commission approves proceeding with those rulemakings, then we're
into several year time-framing and it's not a simple process. It's back
in with NRR putting together rulemaking plans, similar to what they've
got for option two, for other things, and it takes time.
DR. BONACA: And the other thing you want to come up with is a pretty
consistent package. I mean, we criticize oftentimes the deterministic
process for having created a hodgepodge of requirements which have no
consistency at times, and here, if we don't do it right, we are at risk
of getting even more of a hodgepodge of requirements and confusion.
MR. KING: Yes. Well, the intent is to take the hodgepodge and maybe
put some order and sense into it.
DR. BONACA: Okay. That would be good.
MS. DROUIN: Mary Drouin, with Office of Research. One very important
aspect, of course, in this endeavor is getting stakeholder feedback and
interacting with the stakeholders as we move forward. We do have
planned a whole series of public workshops and we had the first public
workshop on September the 15th.
It was very well attended by the industry. We presented, at the
workshop, this preliminary plan that we're going through today and we
did receive quite a bit of feedback.
Also, we had presentations from the stakeholders. NEI gave a
presentation. We had a presentation from South Texas on their option
two. DOE -- not DOE, but a representative who is working on DOE, who
are doing a similar endeavor, looking at the regulations for future
plants and how to risk-inform them, gave us their insights. We also had
some presentations from a couple of consultants.
I will get to, in a minute, some of the things we learned from that.
We will be holding future workshops, as I said. We're going to try and
hold them at some key milestone places, when we have some proposed
changes and when we have some recommendations, and right now we're
tentatively looking in February and in August to have some more
workshops.
Also, one of the insights that came out of the workshop that -- besides
just having workshops, because we have a very aggressive schedule here,
and trying to have some interaction in real time is critical, so it was
decided that we are going to develop a web site. We hope to have this
web site up and working by November.
The intention behind the web site is that as we go along and we have
some preliminary results or views that we can share, to put them out on
the web site, and it will also give a mechanism that the stakeholders
can give us their views as we move along and we don't have to
necessarily wait for these two critical workshops.
At the public workshop that we had back on the 15th, as I said, we
presented our plan. We also had presentations from various
stakeholders. Then we spent the entire afternoon just having an open
discussion, which was very valuable. We got many ideas, not just from
the presentations, but other people who attended the workshop.
DR. UHRIG: Was this here in Washington?
MS. DROUIN: It was here in Washington at the Double Tree. Yes. Right
before Hurricane Floyd. Anyway, in looking at what was discussed and
what we heard, we don't feel that we heard any clear recommendations or
suggestions from the stakeholders on what specific regulations or
requirements that we should just immediately undertake.
Nonetheless, there were two that were mentioned, 50.44 and 50.46, but
there didn't seem to be saying here's your very top priority and go
after it.
MR. BARTON: What is .44 and .46?
DR. APOSTOLAKIS: Tell us what these are.
MS. DROUIN: That's the gas control, the hydrogen.
MR. KING: Combustible gas control is 50.44 and 50.46 --
MS. DROUIN: And .46 is the ECCS.
DR. APOSTOLAKIS: Okay.
MS. DROUIN: Also, there were -- when you looked at current reactors
versus future reactors, there were different views that we got in terms
of different approaches, and we shouldn't use the same approach in
modifying Part 50 for current reactors as we should for future reactors.
For current reactors, it was more recommended to go after specific
things and risk-inform them, but when we start looking at future
reactors, we might want to consider perhaps maybe a complete total
rewrite and starting almost from scratch using a risk-informed
foundation from the beginning.
DR. APOSTOLAKIS: You can't do both at the same time, can you? So I
don't know -- are they essentially proposing that you postpone the
comprehensive revision because we're not building any reactors at the
moment?
MS. DROUIN: I would think so.
MR. KING: I think the folks that were there representing the DOE
programs that's looking for requirements for future reactors, they would
like us to fold that into what we're doing today and they said they're
willing to come meet with us and work with us, maybe almost as a pilot
activity and sharing their views and our views and seeing if they can
get their views factored into what we're doing.
DR. UHRIG: Pebble bed?
MR. KING: No. This is advanced light water reactors.
DR. UHRIG: Advanced light water reactors.
MS. DROUIN: Yes.
MR. KING: Yes. We told them we're not dealing with anything other than
light water reactors in this activity.
DR. APOSTOLAKIS: I share a concern, however, with -- I wrote a note
before the conversation we had. You have two separate objectives there.
I believe, for existing plants, the main objective right now is the one
of burden reduction and focusing on safety issues.
The newer plants, you have really somewhat of a different objective.
You have a number of different objectives, and I question whether you
can achieve both.
MR. KING: What they said was the future plant folks are looking at
reducing capital costs. They are not so much worried about O&M costs in
their activity, but they say capital costs have to come down 30 to 35
percent to be competitive with coal and gas and the only way to do that
is be able to not put in as much concrete and steel and piping.
So they're looking at this activity to get rid of some things, whether
it's get rid of systems or whether it's change containment design basis,
so maybe you can make a smaller containment, I'm not sure, but their
thrust is capital cost.
DR. APOSTOLAKIS: So what's the net result of this or you haven't
decided? Individual recommendations for the current generation or are
you going to take a comprehensive -- do you know? Still discussing it?
MR. KING: In starting out, I think we're going to try and do both. If
we get bogged down, I think the priority will go to focusing on those
things that deal with operating plants, but I think as an initial
approach, we're going to try and look at both.
DR. APOSTOLAKIS: Nobody wanted 50.54 to be revised, license renewal?
MR. KING: Part 54? Part 54. No, I don't remember anybody mentioning
Part 54 at the workshop.
MS. DROUIN: I don't either. I don't either. Then as Tom discussed
earlier, it was already within our scope to keep the design basis
concept and that was also feedback that that was a good idea, that we
didn't get any input that they wanted something different. In fact,
they didn't want anything different.
DR. APOSTOLAKIS: Is there any other way to do it?
MR. KING: We had one stakeholder who wanted to regulate to the QHOs.
MR. MARKLEY: We heard from him.
MS. DROUIN: You heard from him.
DR. BONACA: I'm sorry. I missed it. He wanted to what, regulate?
MR. KING: Put the safety goal QHOs in the regulations and let people
design a plant and demonstrate they meet it.
MS. DROUIN: The QHO.
DR. APOSTOLAKIS: That's granting licensee flexibility.
MR. KING: Don't want to do that.
DR. APOSTOLAKIS: That's it.
MR. KING: That was only one stakeholder.
MS. DROUIN: The other thing which we've heard many times before and we
recognize this, that everyone felt the problems weren't so much with the
regulations themselves, but more with implementing documents, when you
start looking at the regulatory guides and the standard review plans and
how those documents interpret the regulations, that the problems are
really down at that level.
MR. KING: And we'll be looking down at that level.
MS. DROUIN: Yes.
MR. KING: Because I think you have to, or you're not going to get much
mileage out of this effort.
MS. DROUIN: In looking at what we have put together in the plan, there
are two phases to it. The first phase, which is just a study phase, a
study looking at the feasibility of making changes and recommending some
proposed changes to various requirements, and that's what we're going to
be doing over the next 12 months, over the next year.
Then at that point, we'll write a paper to the Commission, with some
recommendations, and then dependent on what the Commission will approve,
then move forward doing a detailed analysis in support of rulemaking for
those changes, which is phase two, which will come later on.
Anyway, in looking at phase one, there are three primary tasks in doing
it. We want to first go through and identify what these candidate
requirements are, looking at the regulations and the DBAs, and, of
course, all the implementing documents. So that in and of itself, just
going through and understanding how all this fits together and coming up
with these candidates.
The next part, of course, will be go through and prioritize them. Then
once we come with a prioritization of which ones to go after first, then
come up with some proposed changes to those.
This is kind of a high level explanation of the plan. We're going to go
through each one of these tasks and go into more detail of what we
intend to do on those, and Tom is going to walk through that.
MR. KING: As Mary said, the first thing we're going to do is go through
and screen what are the candidates that we want to focus on. The way we
plan to do that is basically look at three factors. By candidates, this
will include rules, reg guides, SRPs that we'll look at.
We're going to go in and see where do we feel there's unnecessary
burden, either on the licensee or on NRC, and that could be from
excessive conservatism in methods or criteria based upon today's
knowledge, today's methods, we know we could do better, or on realistic
assumptions, too many failures, too many extreme conditions have to be
assumed one after the other, and it just doesn't make sense when you
look at it from a risk standpoint.
We'll be getting the other technical divisions in Research involved, the
thermal hydraulics folks, the mechanical folks, and we'll also involve
some coordination with NRR, because they're very familiar with the
licensing basis. So we'll be having discussions with them to make sure
we understand what's there and the basis for it.
In looking at design basis accidents, both initiating events and what
the event scenarios ought to be, we'll be doing some screening using
some frequency values. We've put some ideas of what those screening
criteria would be. We think, for example, initiating events, anything
that has a frequency greater than ten-to-the-minus-six per reactor year
ought to be a candidate for an initiating event.
DR. APOSTOLAKIS: I don't understand what that means. A candidate for
what?
MR. KING: To be in the design basis as an initiating event. If it's an
initiating event that's so infrequent, then maybe, from a risk
perspective, it ought not be considered.
DR. APOSTOLAKIS: So now we're mixing the comprehensive revision with a
specific group review revision.
MR. KING: Like I said, we're taking an approach that right in the
beginning is going to look at both.
DR. APOSTOLAKIS: Because the first bullet really refers to what exists
today.
MR. KING: Yes. Yes. But it's --
DR. APOSTOLAKIS: The second bullet now refers to the comprehensive
revision.
MR. KING: Right.
DR. APOSTOLAKIS: You may want to expand the list of initiators.
MR. KING: Or contract it, one or the other.
DR. APOSTOLAKIS: How would you contract it?
DR. BONACA: If the initiating frequency is less than one-ten-to-the-
minus-six, he won't consider it.
MR. KING: Yes.
DR. BONACA: You can't think of many candidates.
DR. APOSTOLAKIS: I thought that was already in the books. Isn't it,
Mario?
DR. BONACA: What?
DR. APOSTOLAKIS: Initiators with frequency less than ten-to-the-minus-
six were not considered. I remember vaguely seeing that someplace.
MR. RUBIN: That may be for external event frequency, because that
number is in the SRP for assessing external hazards.
DR. APOSTOLAKIS: I think we're going to have a problem if we mix
things. Maybe it's early enough in the process to maybe advise you to
clearly identify what criteria apply to the partial revision of the
regulations and what criteria for the comprehensive revision, because
the first one is really the existing and the second one is the broader
view.
MR. KING: Well, the other two, core damage and large early release,
those were to look at the scenarios that lead to core damage and large
early release and what's contained in those scenarios, which would
really affect your description of your design basis accident. Like
single failure criteria may not be reasonable anymore.
DR. APOSTOLAKIS: But do we have -- maybe the reason why some core
damage frequencies are less than ten-to-the-minus-seven is because you
have the existing design.
MR. KING: Yes, but that's where you go to the third bullet, looking at
the existing design, there may be things that are low risk because
they're very high quality, highly reliable. But if you take a look at
them using some risk achievement worth measures, you'll find out that,
hey, those are important. We still want to maintain today's
requirements on those, and that's the third bullet.
DR. APOSTOLAKIS: Which one, risk significance?
MR. KING: Risk significance.
MS. DROUIN: Also, I would add, this is a very complex process and you
should not interpret what's on here in the sense that it's sequential.
This is all very iterative. And as you see on this slide, the next
slide and the one thereafter, they're all called task one, because
you're constantly iterating back through the process.
DR. BONACA: Let me just go back to the comment I made before on design
basis and the mix of deterministic and probabilistic.
I want to size my ECCS system in a way that if I have a LOCA, loss of
coolant accident, I will be able to deal with that, irrespective of how
frequent that accident is. So I have to perform a calculation, maybe
with less conservatism, and I agree with the first bullet there, to size
my ECCS system, the timing of it, size of it, different kind of features
of it.
MR. KING: But which LOCA are you sizing it for?
DR. BONACA: Again, one with less conservatism maybe. Okay. But I'm
saying that irrespective of the initiating event frequency, I need that
result to size my equipment. See what I'm trying to say?
That's why I think when you look at frequency of initiating events to
determine which ones go in your set, you now stumble on --
MR. KING: Let's go back to large break LOCA. There is some frequency
distribution as to the large break LOCA is probably the least likely of
any of the LOCAs to occur.
DR. BONACA: That's true.
MR. KING: And you work back to the small ones and they're more likely
to occur. You could use this screening value to say, okay, large break
LOCA is ten-to-the-minus-eight or whatever, I'm not going to design for
that anymore, require people to design and analyze to that anymore, I'm
going to come back to something that's more in the ten-to-the-minus-six
neighborhood, and what LOCA does that represent.
I don't know, maybe it's an eight-inch pipe break or something like
that.
DR. APOSTOLAKIS: Pursue that a little bit. Let's say, what is the
frequency of a large LOCA now? It's ten-to-the-minus-four per year?
What is it? PRA?
MS. DROUIN: Large LOCA is less than 1E-minus-four. Typically, a value
of 1E-minus-four, but out of the recent AEOD studies, they're saying
it's more on a value of 1E-minus-six.
DR. APOSTOLAKIS: Okay. Now, what does it mean to design against a
large LOCA?
MR. KING: What does it mean in terms of plant requirements?
DR. APOSTOLAKIS: Does that include, for example, the pipe design?
MR. KING: Pipe, emergency diesels, a whole bunch of stuff.
DR. APOSTOLAKIS: So if you remove it now, if you remove it from the
design basis, maybe the pipe will be designed differently and maybe the
large LOCA frequency then would be greater than ten-to-the-minus-six.
That's something that is not clear, in my mind.
MR. KING: That's an issue.
DR. APOSTOLAKIS: but you remove it from the existing design.
MR. KING: I agree.
DR. APOSTOLAKIS: If I start designing against that, maybe the pipe will
be thinner.
MR. KING: But you may still keep the same codes and standards for
piping design, but now instead of assuming this double-ended guillotine
rupture, you've got something smaller which does affect diesel start
time, could affect --
DR. APOSTOLAKIS: My point is that maybe the double guillotine break
will become more likely now.
MR. KING: I understand your point and that's an issue that's got to be
looked at.
DR. BONACA: There will be a shift there and you have to calculate that.
I think it's when you get into calculation to size fundamental elements
of the plant is when I become uncomfortable. And I'm not saying that
you don't have a good argument there. I'm only saying that I guess I'm
too deterministically-based to -- I would like to -- I understand what
you're saying there.
MR. KING: You're arguing for a don't get into the design stuff, just
get into the stuff that --
DR. BONACA: Well, I'm arguing that some specifics are there to size
equipment that you were going to know to be successful under the most
limiting conditions. Now, when you begin to -- I understand where
you're going now.
You're saying, well, you know, leak before break, large piping of that
kind will not -- a guillotine break will not happen, and probably you're
right.
DR. APOSTOLAKIS: See, but the fundamental question is something is
insignificant now because I have designed it according to certain
criteria. If I design something else to a new set of criteria, that
something may not be significant anymore. I don't know how -- I mean,
unless you do a PRA again and you repeat all the calculations to
convince yourself that even under the new design, the large LOCA is
still ten-to-the-minus-six.
But remember, in this part of task one, you just identify it as a
potential candidate.
DR. APOSTOLAKIS: I understand.
MS. DROUIN: So as you go through the rest of task one and looking at
the history of the requirement, which we're going to get into, and why
it was there and what it's doing, well, then, that may no longer be a
candidate. It might be thrown out, or you might end up picking up one
that you didn't identify.
DR. APOSTOLAKIS: I understand that and that's a valid argument. All
I'm saying is that this conceptual problem of finding something as
insignificant in the present case and then changing the requirements,
that may not be insignificant in the new case. Somehow you have to --
MS. DROUIN: But my point, you haven't made the decision here to change
it. You've only made the decision to look at it.
DR. APOSTOLAKIS: And when you look at it, you can say a lot about it.
MR. KING: Absolutely, your concern has to be looked at.
MS. DROUIN: Yes.
MR. SIEBER: Isn't the fact, though, that the reason why reactors can
withstand some of these pretty severe accidents is because the ASME code
specifies pipe thickness and materials and weldments and supports, and
on your slide five, you say you aren't going to touch that.
So all those criteria still remain in place. It's just what you look at
from a risk standpoint which allows you to resize auxiliary systems.
DR. BONACA: The point that George is making is a good one, however,
that you may decide that because of all this knowledge, you're not going
to consider anymore a guillotine break. Therefore, that will cascade
into lesser thick piping and all kinds of stuff, which, in turn, will
make frequent anything that wasn't frequent before.
DR. APOSTOLAKIS: Anyway, I think we have an understanding. Just out of
curiosity, would it be helpful here to also develop something like a
master logic diagram, top-down diagram, revisiting the whole idea of
initiators and so on and show the logic of it?
You know what a master logic diagram is. The PRAs, especially in the
early days, it was a real good communication tool to say why do we worry
about LOCAs, transients and so on, because public health has to be
protected; that means you have to release radioactivity, that means you
have to have damage to the core and the containment failure, then you
have two branches, how can the core be damaged; well, what do we do
there; we produce heat and remove heat.
So you look at the various disturbances there, what will happen to the
containment and so on, and that would be a great, I think, diagram to
compliment this, not to replace. So that you will show now if I take a
risk-informed approach, what would be my initiators that I would
consider down here.
The diagram itself would not do it. You still have to consider all
these things that you have here, but I think the diagram will help two
ways. First of all, it may give you some idea as to enhance this kind
of thinking, but, second, primarily, I think, as a communication tool,
it would be great to show the systematic way that you are thinking.
I think most PRAs do show these. They copy each other, but still
they're there. I've always felt that it's valuable more as more of
communication than actually helping you find initiators.
MS. DROUIN: We've already started doing something that doesn't look
exactly like a master logic diagram, but it does a similar thing.
DR. APOSTOLAKIS: That would be a good idea.
MR. KING: I think that's a good idea. The systematic way to illustrate
what we're doing.
DR. APOSTOLAKIS: Now, I would expect here to see things like this thing
about earthquake and large LOCA. Will that be a candidate here to be
considered? Would that count as an initiating event or what?
MR. KING: What? Say that again, which LOCA?
DR. APOSTOLAKIS: The large LOCA.
MR. KING: Yes.
DR. APOSTOLAKIS: In an earthquake. Is it part of the design basis now
that you consider both at the same time?
MR. KING: Yes. That would fall under the item that I call unrealistic
assumptions.
DR. APOSTOLAKIS: So it's not --
MR. KING: You're starting to add all these low frequency things
together in the same scenario. That's what is meant by those words.
DR. APOSTOLAKIS: Because each one is still there as an initiating
event.
MR. KING: Right.
DR. APOSTOLAKIS: In separate parts of the analysis.
MR. KING: And then these criteria down here would be a way to screen
how unrealistic they are.
DR. APOSTOLAKIS: Okay.
MR. KING: And then as Mary said, once you go through the screening
process and identify those things that look like they're candidates to
be risk-informed, then what we want to do is target those to make sure
we understand why they are the way they are, before we start embarking
on changes.
This is just a list of the kind of things we would go in and look at,
dig into the reg guides, the SRPs, talk to the NRR folks, make sure it's
clear, we understand what's there and why it's there, and then, with
that good understanding, go in and see what makes sense to change.
In addition, we need to think about --
DR. APOSTOLAKIS: Wait a minute, wait a minute, wait a minute. Let's go
back to ten. Throwing the words out, identify the purpose for each
requirement, defense-in-depth, marginal uncertainty.
Some of us would think that's why you have defense-in-depth. It's not a
separate thing. If you had no uncertainty, you would not need defense-
in-depth.
I think maybe you can point out again that some of these policy issues
regarding -- that are of defense-in-depth in the new system really have
to be resolved by the Commission before you guys go too deeply into
this.
MR. KING: Well, that's one of the things we'll talk about when we get
to the schedule, but my view is when we go in October with this plan,
what we're going to ask for Commission approval on is that general
approach that I talked about early on and we're going to ask for
approval of those screening criteria.
Then we owe the Commission a report later on. We're proposing to go
back to the Commission around the February-March timeframe, after we've
done the screening, after we've taken a regulation and run it through
this whole process, and then go back and have them approve the criteria
we would use to actually make the risk-informed changes or come up with
the recommendation for risk-informed changes, which then would get into
what do we mean by defense-in-depth, what kind of margin do we think is
reasonable to retain, what's the split between prevention and
mitigation, those kinds of questions, what risk criteria are we going to
use.
We're going to talk about some of that later on.
DR. APOSTOLAKIS: I mean, here, you're just identifying the purpose,
just the history.
MR. KING: Yes.
DR. APOSTOLAKIS: You are not really taking any action.
MR. KING: This is history. This is history.
DR. APOSTOLAKIS: Because somebody says, yeah, this was in the name of
defense-in-depth and defense-in-depth remains a principle that's above
everything else, then the natural conclusion of that is that in the new
system, you would have to do that.
MR. KING: Right.
DR. APOSTOLAKIS: If, on the other hand, the Commission says, no,
defense-in-depth is really a tool for achieving certain things --
MR. KING: Yes.
DR. APOSTOLAKIS: -- then you look at it in a different way.
MR. KING: Yes. To me, the key question in this whole thing is this
slide. To me, it's fairly straightforward to go through and identify
those things that bother you, that either the industry will say these
things are costing us money or we'll say these things don't make sense
from a risk standpoint.
The tough question is I don't like what's there, what do I like, what
will I change it to, and that's where you get into the role of defense-
in-depth and the risk criteria that you're going to use to make those
decisions. That's what this slide really gets to.
These are things that are going to have to be considered and maybe -- I
think we talked about most of these, except -- already, between this
morning and this afternoon, but the one we haven't talked about is the
anticipated operational occurrences. There are, in the design basis
envelope, these events identified that are things that are going to
happen one or more times during the life of the plant, whether it's a
turbine trip, a loss of off-site power and so forth.
The plant has to be designed to cope with those and it has to be
designed to cope with those with either no radiation release or a very
small amount.
We don't want to throw those away. I mean, even though a risk
assessment would say there is no risk there, the fact that they do occur
means that you want the plant to have a good design to be able to handle
those.
So my view is that, at this point, we don't want to touch those. We
probably want to leave those alone. But it is an item that we need to
put before the Commission and maybe the committee needs to think about
it, but it's something we need to look at in this risk-informed process.
DR. APOSTOLAKIS: Of course, all of this, again, will heavily be related
to the goals, if the Commission decides to revise high level goals, land
contamination and things like that, and those then are impacted.
MR. KING: Clearly all of this stuff up here could be impacted by that
kind of decision.
DR. APOSTOLAKIS: Also, in the third bullet, risk metrics, you are
reconsidering the whole thing and you are still stuck to CDF and LERF,
would the frequency consequence curves be considered?
MR. KING: I think at this point, nothing is thrown out. Certainly,
CDF, LERF, risk achievement worth, Fussel-Vesley, they're all candidates
to be considered.
DR. APOSTOLAKIS: But these are already being used.
MR. KING: Yes.
DR. APOSTOLAKIS: I'm talking about frequency consequence curves, which,
in this country, they are not used. But, for example, if you use a
frequency consequence curve, then you can do what Ridge Farmer did 32
years ago, for the anticipated operational occurrences, you are forcing
the curve to turn around. I remember his words in the paper, "We want
these to be less frequently largely because of the nuisance value of
anticipated occurrences."
In other words, there is no risk there, so the curve would have gone
straight up. The frequency consequence straight up, but when it comes
to very low consequences, high frequency, he forces the curve to turn
around, largely due to the nuisance value.
So there are clever ways of doing things like that using one metric. So
that's the kind of thing that perhaps you want to -- take a fresh a
look, that's all I'm saying.
MR. KING: Nothing is off the table at this point.
DR. BONACA: But I think that it's important for anyone making the
decisions also to have a clear understanding here of this layering of
expectations that were set up in the original design, because if you use
just the CDF and LERF, you're just using the highest material there.
There is no intermediate.
You've got to understand what we're going to replace the existing body
of regulation with and what the expectations are going to be and so on.
So that's a good point here, but it would be interesting to have almost
like a summary. I would like to see it presented in a way that if I'm
looking at a logic diagram that George was mentioning before, I can also
look at the other, the old logic diagram, really, which was based on the
expectations for anticipated transient and all those things.
MR. KING: I understand your point and I think we need to, as we get
into this, do that. Again, at this stage, we're not proposing answers
to these things. These are just being put forward as things as we get
into the study that have to be dealt with.
Again, my own view is this is the heart of the whole thing.
DR. APOSTOLAKIS: That heart depends on another bigger heart, the safety
goals.
MR. KING: True.
DR. APOSTOLAKIS: The Commission says go with what we have now, then you
do it in a certain way. If they say no, we're changing a few things,
then you do it in a different way.
Is the Commission aware of these things that are to be revised in the
safety goal policy statement?
MR. KING: At the Commission briefing on September 7, we made these
connections with the Commission.
DR. APOSTOLAKIS: Good.
MS. DROUIN: And which risk metrics and criteria you choose and the
reason we had it on there is because we have not pre-decided and it's
not just CDF or LERF, because it could be highly dependent on which
requirement you go after and which one is best suited to make that risk-
informed.
DR. APOSTOLAKIS: Fine.
MR. KING: Okay. The next, task two then is once we've got these
candidates and we understand them, how do we decide which are the ones
we want to work on first. So we got this prioritization step in there.
That will probably be based upon some qualitative judgment. There may
be some quantitative cost-benefit kinds of considerations, but one of
the things the Commission asked us to do was to -- if there are things
that come out of our study that are obvious candidates for change, don't
wait till the end; let's bring those up right away.
This would be a step that could identify some of those and, also, when
we go to the Commission with a study, we may have so many things on our
plate that by December of 2000, we can't look at all of them. So we
want to look at the ones that are most important and then go to the
Commission and propose a follow-on activity to look at the rest.
So we feel this prioritization is important to get in fairly quickly in
the study process.
MS. DROUIN: The only thing that I would add here, I think this is one
step in particular that we really need some industry feedback, because
whereas we can point to what our resources are, where the best benefit
in terms of reducing unnecessary burden from the licensee, we don't have
that data.
So that's feedback that we really would like from industry, from the
stakeholders.
MR. KING: Yes. I think the biggest piece of missing information is the
burden piece and it's really industry is in the best position to
identify that. We brought that up at the workshop. We've got some
verbal commitments to work with us on that, but that's really where we -
- we can't develop that ourselves. We've got to have their help on
that.
Then task three, you've got the candidate list, you've put them in
priority order. Then you've got to go in and come up with a
recommendation to the Commission. That involves using the criteria we
talked about a couple slides ago and it's going to involve some work,
some engineering work.
The recommendations that we want to present are not going to be in the
form of a proposed rule or a proposed reg guide. What they're going to
be is they're going to lay out to the Commission the scope and nature of
the changes and do enough work to establish the feasibility. In other
words, that you do, by making these changes, you actually do make
improvements, whether they're improvements in safety or improvements in
unnecessary burden reduction or consistency.
Then if the Commission says yeah, we agree, then the more detailed work
that you would need for regulatory analysis and so forth would take
place.
So what we had in mind was, for example, if we identify a large break
LOCA scenario that we think is too many excessive conservatisms, we do
analysis like analyze what's on the books today and then analyze it in
the best estimate fashion and that would identify the potential
improvements you could make, and then you'd have to decide, okay, I want
to get rid of some of this unnecessary conservatism and make some
judgments on what you would change the new scenario to, the new
assumptions to, and then do another calculation to show what benefit you
gain by making these changes, and then go back to the Commission and
recommend, in a conceptual way, a ballpark way, what changes we think
would make sense to make.
So that's really what this task three is all about. I want to mention
this fourth bullet down here. We also have to decide, for example, if
you take peak clad temperature, do we want to just come up -- do we
think the 2200 degrees in the regulations now is excessively
conservative, do we want to just change it to some new peak clad
temperature that we think makes sense or do we want to take a look at
the basis for that number, are we trying to prevent cladding failure,
are we trying to limit the number of cladding failures or the types of
cladding failures, or are we really just trying to prevent a full core
damage accident.
Today's 2200 degrees and 17 percent oxidation have one basis as to what
they're trying to achieve, but from a risk-informed standpoint, we might
want to go in and take a look at those bases and see do we want to
change those, as well. So that aspect is thrown in, as well.
As Mary said, it's an iterative process. This is the iterative slide,
which shows how we go through and each task sort of -- we have to go in
and test, come up with a recommendation at each point and then go back
and test it.
You might have to cycle through several times before you come out at the
end and say yes, I do meet those desired characteristics, I want to go
forward with this recommendation.
MS. DROUIN: At each step of the process, it's a learning thing and so
whether you're in the very first task when you identify and then when
you start getting into the prioritization or even when you start getting
into the changes, you might learn new things that put you back to
either, say, okay, this is no longer a candidate or I've looked at it
the wrong way, because everything, when you get into one requirement
feeds into another and how they -- it's this tapestry that could totally
unravel if you don't constantly look at it an integral fashion.
MR. KING: One thing we want to do to try and test out the method we're
using for the study is to take one rule and just run it through the
whole process quickly. It was suggested at the workshop 50.44, the
combustible gas control rule, would be a good one to do that, where you
go in, identify those things that look like candidates for change, make
sure we understand the basis, come up with some recommended revisions to
it, test it against the criteria, desired attributes criteria, and then
use that to refine the criteria that we're using for screening, for
deciding on changes for dealing with these questions that we talked
about, and try and do all of that by January, so that that will then
help bring the remainder of the process to give it a test, bring it to
some form that we think is a fairly final form, and then we would send
that to the Commission as what we're going to use for doing the rest of
the -- looking at the rest of the regulations.
So anyway, it's a trial run, as quickly as we can do it, to test out
this whole thing.
Issues. We've got a number of issues that have to be dealt with in the
study, and we've talked about most of these before.
DR. APOSTOLAKIS: We've discussed them.
MR. KING: See if there's anything new here.
DR. APOSTOLAKIS: That's fine. They have to be resolved.
MR. KING: Yes. They have to be resolved. At this point, they're open
questions.
DR. APOSTOLAKIS: Does anybody disagree? So let's go to 18.
MR. KING: Okay. Schedule. As I said, the test case, we're shooting
for January to have that done. At that point, we would have a workshop
that would focus in on the results of the rest case, as well as try and
finalize the criteria we're going to use for the rest of the study,
elicit some feedback, come back to the committee, this committee, and
present the criteria or final criteria and approach that we're going to
use for the rest of the study.
DR. APOSTOLAKIS: So ACRS, you mean the subcommittee or the committee?
MR. KING: I would expect you would want a subcommittee and I would
expect we would want a full committee. We would like a letter.
DR. APOSTOLAKIS: Are we writing a letter this time?
MR. MARKLEY: To whatever extent you choose.
MR. KING: We would like a letter, at this point in time, on what we
present today and whatever we present at the full committee next week.
We would like a letter on that now.
DR. APOSTOLAKIS: It's the same letter as the one for option two.
MR. MARKLEY: You can package it together, yes.
MR. KING: Then from March through approximately August, we would go
through and apply that process to the other candidate changes. Again,
have a workshop, shooting for September. Based upon that, finalize the
recommendations, come back to the committee around the November
timeframe, and our target date to get back to the Commission with
recommendations is December of next year.
Again, if the list is too big of things that look like they're
candidates for change, my view is what we would do in December of 2000
is go as far as we can on the highest priority ones, come back to the
Commission with those, not hold everything up waiting till we get
through the whole list, and then recommend that we have a follow-on work
to look at the rest of them.
So our target date is to give the Commission something in December 2000.
If it's the whole list, if it's a partial list, remains to be seen.
DR. APOSTOLAKIS: Any comments from around the table?
MR. BARTON: It's a lot of work in a short time.
DR. APOSTOLAKIS: A lot of work.
MR. BARTON: Short time.
DR. APOSTOLAKIS: Okay. Thank you very much, again, Mary and Tom.
We will take a break. We're ahead of schedule anyway. So back at 25
after the hour.
[Recess.]
DR. APOSTOLAKIS: Okay. We're back in session. Now we will hear from
industry on option three. Mr. Heymer.
MR. HEYMER: Good afternoon, again. My name is Adrian Heymer. I'm a
project manager at NEI on the reg reform group.
This might take a little bit longer than 15 minutes, but I'll try and
move forward as fast as I can.
DR. APOSTOLAKIS: We'll help you. You can be sure about that.
MR. HEYMER: Improving the technical requirements associated with the
NRC regulations is part of this overall approach, which we think is a
full-phased parallel effort, improving the oversight process, the scope
of SSCs governed by the regulations, which were discussed this morning.
Then comes improvement of technical requirements, which we're going to
discuss, and then the administrative and process improvements, which, in
some ways, is a catch-all for stuff that tumbles out more on the process
side, and, as Biff Bradley said this morning, that's things like 50.72,
50.73.
The industry's oversight on this is predominantly through the NEI risk-
informed regulation working group, chaired by David Helwig, of ComEd,
but there's also owners' group activity and some activity in the co-
committees, and we're endeavoring to coordinate these actions through
the setting up of probably an issue task force just for this specific
activity.
I think our view is consistent with that of the NRC, is identify what we
see as the potential candidate regulations, assess the benefit, look at
the options, make sure that we assess what the real benefit is,
prioritize the list of candidates, and move forward on rulemaking.
It's not necessarily in that order. We think that some areas, such as
on 50.44, we've already got a lot of information, there has already been
a lot of work and activity in that regard, and we think you could move
forward, use that as a test case, and probably initiate rulemaking as
soon as possible, just on the information that we have to date.
Work has already started in some areas associated with LOCA and post-
accident sampling and I think these should also -- this work needs to be
factored in with what we -- with the studies that are going on.
I guess the important thing is that where we are today, we want to build
on what we've learned over the past 30 years. We want to build on
regulating and operating experience. We want to incorporate new
information. And after 30 years, I think it's an opportunity to sit
back, take stock, see where we are and see how we can improve the
process as we move forward into a restructured generating environment.
The risk-informed activities that have already been started or are still
in hand, such as those associated with tech specs, ISI and IST, we
should expedite those and perhaps try and push them a little bit further
than we are planning to do at the moment, just through the common
interactions.
Our main goal is to improve the efficiency and the effectiveness of the
regulations to get smarter, and in doing that, when you talk about
technical requirements, I agree with some of the statements made here
today, you've got to be careful. What initially is the most obvious and
straightforward approach may not, in fact, be the smart thing to do. So
I think you've got to sit back and assess it, and that's where we
support the NRC's view that let's assess these, let's look at the
benefit, let's look at the alternatives, and then make a decision,
rather than just charging forward on the first thought process.
The other issue is, and it's not just the regulations, it's the reg
guides, it's the inspection manuals. Some of the regulations -- in
fact, most of them are just general statements and English is a language
that has its roots in many other languages. Some people say it's a
language for lawyers, but you can read and interpret words in various
ways.
The only problem is, for the past 30 years, we've had a set of words
that we've interpreted in one specific way, things like safety-related.
You say safety-related to people in the industry and that means a
specific thing.
When you go through a change process, if you say safety-related, that
still means the old words, the old interpretation. So perhaps in some
cases, you may need to change the rule just to affect the cultural
change as much as the technical change.
I think more of an issue than the regulations is the interpretation in
the reg guides. Recently, we've contacted the industry, based on the
statements that were made at the workshop, and have asked them to
provide us additional information on what reg guides do they think
should be changed and what is the benefit, with the aim of providing
that feedback to the staff.
We expect more significant language type changes or more changes to the
guidance documents than we do to the regulations.
This is just an initial set, our initial cut. What we did is we sat
down and we said what are the criteria that we would look at. There are
six of them here. There were a few others, but these are the main ones.
We then used that criteria to go through the regulations and try and
identify the set of regulations that we would look at and assess under
option three or phase three, as we tend to call it.
It's by no means the final set. We did show them to the risk-informed
regulatory working group. They're still thinking about the list of
regulations we gave them. We've also asked the industry to provide us
additional input, which we hope to feed back to the staff probably by
the end of November.
At that point, I'm just reading what's on the slide.
I guess changing the regulation that would minimize the need for
exemptions, although it's not specifically part of option three, the one
that springs to mind is fire protection in that instance, and there is a
fairly intensive effort going on in that regard.
The other important thing here is what we found is when we went through
the regulations, that there are -- in a number of areas, a change that
is made, for example, in 50.46 cascades down into various other
regulations.
What we tried to do is to say, well, what sort of regulations are those
and where would that come out, and we included that in our list.
This is the list. I'm going to touch on this and speak to this a little
bit more in-depth in the following slides. Some of these are
placeholders. As we said this morning, on 50.59, we might, in fact,
implement a change process, a complete change process for 50.59 under
option two. So there are some placeholders here.
On 50.54, we're not sure whether or not you can actually make changes
under 50.54 before you've actually done all the other regulations,
because a number of the license conditions are linked in some way to
some other specific regulation.
As regards priority --
DR. APOSTOLAKIS: Now, your list is not different from the list that the
staff showed?
MR. HEYMER: No, no. Not at this point in time. As regards priority,
we think the one that sort of stands out is 50.46 and Appendix K. One,
because a number of other regulatory requirements sort of flow from
these, a lot of the guidance documents are linked to these regulations,
and the industry has already started work and I believe at least one of
the owners' groups is coming in to talk to the NRC in the next couple of
weeks specifically about 50.46 and perhaps what are those plans in that
area.
And while we are talking about owners groups, it is our intent to try to
bring the owners groups together so that we don't have four separate
owners groups going into the NRC staff and talking about 50.46 or LOCA,
but rather go in as an industry rather than as four separate entities.
So there is a coordination element in here.
Some of the changes on 50.46 associated with assumptions, input to the
analysis, and it's not necessarily the first thing that springs to your
mind. A lot of people say it's pipe break size. Well, if it isn't a
large break LOCA, what size of pipe are we talking about; then there was
the question that was discussed when the NRC were providing their
presentation; well, if you don't focus on the large break LOCA, do you
change the design in any way that makes that perhaps a little bit more
probable.
So I think you need to look at that, but you need to look at some of the
other approaches that are out there, look at the different scenarios.
Perhaps there's more benefit in looking at a specific scenario than just
going after the large break LOCA.
The other thing you've got to look at is, is there a generic benefit to
the industry. A large break LOCA may be of benefit to some plant and
may be minimal benefit to the others. That comment has been made.
As regards the scenarios, obviously, one that springs to mind is the
loss of off-site power. Other areas, decay heat, peak cladding
temperature, and so forth, and I think here, especially with .46, it is
let's assess it, let's see, let's think about it, and don't go charging
into it. We can't afford too many false starts and we've got to get it
right. So we need to move forward with care.
The other thing is once we've sorted ourselves out on 50.46 and the LOCA
issue and Appendix K and the methodologies, I think that may open up
some other areas, such as in the fuel design and fuel requirement that
are linked to some of the general design criteria in GDC-28, I think.
As I spoke about earlier, we think 50.44 is a candidate. A lot of work
has been done and we think we could move forward with rulemaking in this
area next year.
I think we've been working at this since -- certainly for at least ten
or twelve years, if not longer. I think we do have enough information
to move forward.
On the technical specifications, there is some activity already going on
outside of this area associated with end states, surveillance
requirements, allowed outage times, and when do you actually have to go
to shutdown from a 303 issue.
I think those need to be expedited. I think, having looked at those, we
will then get a better idea of do we really need to change the
regulation beyond perhaps what we're changing under option two.
The other thing that option two brings to mind is that as you go through
option two, you may identify some areas that are candidates for option
three. So I think this will be an evolving structure. For example,
especially those SSCs that go into the commercial T or box three, as the
NRC staff called it.
On equipment qualification, the synergistic effects, the margin, and
some of the way that the language is written, I think, we could improve
in the interpretation on that. On the TMI requirements, again, somewhat
linked primarily to 50.44, but control room habitability, post-accident
sampling, some of the QA requirements, the way they're written in there,
I think we might want to take a look at; the how to's as opposed to the
what's.
Again, that may be linked more to the guidance documents and the
standards than the specific regulation, although I think we're going to
have to change 50.34.
On codes and standards, 50.55(a) I think is like 12 pages. It's not an
easy regulation to read. I think we can probably go further, a number
of people have suggested we can go further on the ISI/IST than we have
at the present time, and I think that's worthwhile taking a look at.
I think there is a terminology and a consistency in language that we
need to focus on, so that the codes and the standards use the same
language and terminology that we use in the regulatory world, maybe to
ease the interpretation issues.
I also think that once you get into this and you move forward and get a
better handle on what we're doing under the 50.46 and Appendix K, you
might want to go back into the codes and standards and adjust them from
the technical design basis, but, again, I think you're going to have to
look before you step forward in that regard, because we have had a
pretty good record over the last 30 years of operating.
A lot of conservatism is in there and before you remove it, especially
when you're talking about some primary coolant pressure boundary and
criteria that relate to that, I think you've got to be a bit careful.
You want to make sure there is water in the pool before you go off the
ten meter board.
On Appendix J, a number of people want to take a look at this, but
Appendix J is very much like the primary coolant pressure boundary. You
want to be careful with it. I think it's how you explain the changes is
just as important when you're talking about containment as actual what
you're, in fact, doing.
There are some hard systems within containment that perhaps don't need
the same degree of testing that we apply today.
MR. BARTON: Is Appendix J looking for -- you've already got some relief
on Appendix J with respect to the timing of testing. Now you're looking
for eliminating some of the components, the scope of testing or what?
MR. HEYMER: Perhaps eliminating the testing requirements or removing
the limitation that's in there, in some of the guidance documents, which
I believe is a timeframe of five years. That's not to say we're never
going to test them. That's going to say that you're going to have to
have some form of evidence or some criteria to say the testing of these
is not as important as some of the others.
If you had a hard pipe going through containment that's Class II
qualified, the piping out of boundary, if you like, is the containment
boundary, the isolation valve is a nice to have feature that's out
there, should the pipe be broken for some reason. That's what we're
saying. It's worthwhile taking a look at that, at this point in time.
MR. BARTON: You're looking at eliminating some of the testing, some of
the scoping of Appendix J.
MR. HEYMER: The GDCs, I think, are an example where the language is
very much, in many cases, engineering motherhood. There are some
specifics there, but I think what flows from the GDCs that you need to
look at.
And on Appendix E, which is emergency planning, I think we're not
looking at the off-site plan at all, but we certainly think we could
make some improvements on the on-site plan, perhaps along the lines of
manning levels, how many people must you have that are required to come
in at 30 minutes notice, how many people at one hour notice, so forth.
So that's where we stand on that.
The preliminary list, it's a very cursory overview on oversight. We've
been really focusing on the oversight process and option two up until
now. We're just beginning to move on option three and really take an
extensive look at that. We take to heart the comments of the staff that
we need to give them input for this to happen and we're going to try to
do that certainly in the near term, and we'll definitely have that
information for them by their next workshop.
We think it is worthwhile pursuing this. It's the focus on the right
stuff, those things that do have safety-significance. I think the
direction in which we're moving gives us a degree of flexibility that
helps us to maintain safety in a competitive generating environment.
It's a more efficient and effective use of resources and we do think it
will be the basis for improving the ALWRs as they're designed today or
for any new plants that come along.
I guess in conclusion, we support the staff's initiatives or the NRC's
initiatives, we agree with their plan. We think it's a necessary and
natural step forward.
If you look at where the industry is today, do they need it? Probably
not. But as you look forward sort of eight years from now, they're
probably going to need something along these lines to continue to move
forward and make improvements to the plant while maintaining safety.
DR. APOSTOLAKIS: Adrian, you are using the words risk-informed
performance-based approach, and we have heard next to nothing on
performance-based today.
MR. HEYMER: Yes.
DR. APOSTOLAKIS: Are you going to make that an issue and request that
the staff pay serious attention to performance-based regulation?
MR. HEYMER: I think the performance-based element is in the oversight
process. I think we heard it this morning as regards to once you've
recategorized it, you're going to have some monitoring criteria.
If you look at box three and probably box two, you're going to have some
commitments to functionality which I think are going to be linked to
monitoring and the performance of the equipment.
As regards the technical requirements, we haven't really thought how the
performance element comes into that, because at the moment, we see it
more in the oversight process. So that's where we see that being
buried.
The last point on there is on communication and coordination. We are
talking about changing the way we do business, improving it. Change is
never easy. I mentioned the example of the term safety-related and for
that, there's many others, and the way we've interpreted regulations, it
means something to me, it may mean something totally different to Mark
Rubin and Tom Bergman there that sit across the table.
So I think it's worthwhile and it's very important to have not only
constructive interactions between the industry and the NRC, but
constructive interactions within the industry and with the general
public to explain this.
I think what we did and what we're doing under the first part, which is
the oversight process, sets a framework for those interactions; a lot of
workshops, a lot of information flowing, and that's really where we are
today.
It's not very specific. We're just getting started, but at least -- and
I went through it fast, in the interest of time, but I think it's an
important element that while some people see we're going to do step one,
step two is a question mark. I think once you look at some of the
advances we can make through the technical requirements, I think more
people will come on board with the risk-informed performance-based
approach.
DR. APOSTOLAKIS: Now, again, your first bullet says industry fully
supports NRC initiatives. Is this sort of a general statement or you're
referring to what we heard regarding options two and three?
MR. HEYMER: As regards the overall approach, which covers oversight,
option two, and what we've heard so far on option three. I mean, I
think there are some variations as what we heard today in option two.
We're in the same book, we're in the same chapter of the book. They may
be on page 22 and we are on page 15, but I think that's down in the
details.
DR. APOSTOLAKIS: Good. Any comments, questions? Staff? Public?
Thank you very much, Adrian. Appreciate it.
The final presentation for the day is by Mr. Riccio, on the revision of
10 CFR Part 50. Would you tell us who you represent?
MR. RICCIO: Certainly. My name is James Riccio. I'm the staff
attorney for Public Citizens Critical Mass Energy Project. It's a
pleasure to be here in front of the ACRS. It's one of the few places I
feel that you can come here to legitimately debate about the issues and
I've been coming to your meetings for about a decade.
That being said, I have heard a lot of things around these tables that
have given me reason for concern with the direction that the NRC is
heading with this risk-informing Part 50.
I keep on hearing that we're here because we want to reduce the burden
on the industry, and, quite honestly, that is not, to my mind, a
legitimate concern for this agency. This agency's concern is to check
the public health and safety, not look out for the financial interests
of this industry. And the reality is the reason we're here is because
the industry doesn't feel it's going to be able to withstand the
competitive environment in which they're now entering into.
The public views this as another item in the long line of deregulatory
efforts that have been underway at this agency, some of which I have had
the pleasure in participating in those workshops, as well.
We've had reduction of requirements marginal to safety, we've had cost-
beneficial licensing actions, we've had the tech spec re-write, which
dropped the limiting conditions for operation by 40 percent, and now
we're -- all these efforts weren't, obviously, enough to make nuclear
power competitive in the new environment, so now we're going to
basically try to apply PRAs to Part 50.
We have several -- I have several problems with how this approach is
being taken and part of it goes back to the design basis of these
reactors. Your PRAs are premised upon the fact that your reactors meet
their design basis. It's my understanding and my belief that they don't
and until this agency can explain to me how, for instance, you had
Haddam neck operating for 28 years without an emergency core cooling
system that would have performed its function or how you could allow
Maine Yankee to operate since its construction with cable separation
problems or how Big Rock Point could basically have a borated water
storage tank that wouldn't have functioned for 13 years, we're going to
have problems as to whether or not we meet the design basis.
These are just minor examples of what I think is still a pervasive
problem in this industry.
DR. APOSTOLAKIS: Do you have a document where you list those? I would
like to read about it.
MR. RICCIO: Actually, I have it. Those are listed in my report and I'd
be happy to send it along to you.
DR. APOSTOLAKIS: I would appreciate that. Would you send a copy to Mr.
Markley?
MR. RICCIO: Certainly. I have one here, actually.
DR. APOSTOLAKIS: Thank you very much.
MR. RICCIO: Having said that, I've been coming to these meetings for a
good deal of time and I don't mean to throw back your own words at you,
but I've heard a lot here that gives me reason for pause; things like
PRA means never having to say you're certain; things like this is
regulation by religion.
If what you've done with Farley or if what the agency has done with
Farley is an example of how this is going to work, I have real concerns.
There are three analyses that were done. You did a deterministic that
said inspect, you did an analysis that was part deterministic, part
probabilistic, and that said inspect, and then there was the purely
probabilistic analysis and that said you guys are okay.
That's where the agency relied upon. They relied purely upon the
probabilistic assessment, when the other assessments said you really
should be taking a look at Farley's steam generators.
You also have DPOs on the books in regards to steam generators that
really, to my mind, haven't been resolved. Some of the comments, we
haven't seen enough accident scenarios that have gone into the steam
generator to give these Commission the comfort level that they
supposedly have.
I guess what's going on here is I see the safety net. Instead of seeing
the net, I see the holes. The reason that -- at least the reason that
NEI has used before the oversight committees that they're pushing this
agenda is that because of the improvement in safety and the good
operating history that this industry has had over the last few years.
We will debate that till the end of our days. But there was a comment
made by the ACRS years ago that struck me, and I'm going to paraphrase
it, but to think that you're safe because you've operated safely for a
finite period of time, the belief that that means you believe you have
an adequate level of safety is a psychological trap and I believe this
agency and this industry are walking into a psychological trap.
And I don't recall the gentleman's name who brought that up, but it was
very legitimate at the time and I think it's even more so legitimate
now.
He brought up examples like, you know, prior to Chernobyl, the Soviets
thought they had an adequate level of safety and it turned out not to
be. Prior to the Challenger explosion, we thought we had a -- NASA
thought it had an adequate level of safety and it turned out not to be.
Right now, this industry believes that it has an adequate level of
safety, but it doesn't have enough history. One of the reasons -- one
of the examples of that is the fact that I look at your core damage
frequencies and less than one-times-ten-to-the-negative-seventh, that
has no basis in reality. You're talking one-times-ten-to-the-negative-
four even has no basis in reality.
If you look at the history of this industry, you've had two core melt or
two core damage accidents in less than 2500 reactor years, and that
doesn't even include the three test reactors that were melted down, two
in Idaho and one in Pennsylvania.
So to tell me that you have a core damage frequency of ten-to-the-
negative-four to ten-to-the-negative-seven doesn't really wash.
I hear the industry saying, oh, we want to instill some reality into the
situation. Well, look at that reality. Maybe the large break LOCA
isn't very realistic, but neither are your core damage frequencies.
We also -- and it puts a chill down my spine to hear people talking
about maybe we can risk-base away containment. I've been coming -- like
I said, I've been coming to these meetings for a good deal of time. I
was at the meeting where Mr. Catton talked about the direct taurus event
and how the fact that if you didn't know exactly what you were doing,
you were going to reintroduce all the radionuclides that you had
scrubbed through the spent fuel pool right back into the environment.
Unfortunately, that never made it into the transcript.
I also have a pretty good memory of the original version of -- is it
1250, NUREG-1250, on containments? I'm sorry, I don't recall the exact
NUREG number.
But the original version of that said that an early containment failure
could not be ruled out for any of the designs inspected. Of course,
that was removed when it went to final draft.
I guess what I'm saying is I see large holes in your safety net. I
don't believe that risk-informing Part 50 is going to improve safety. I
think it's going to reduce the margin of safety that I think right now
may not be adequate.
I'm going to participate in this process. There will be others from the
public that will participate in this process. I think you'd better
include in your schedule the likelihood of a lawsuit, because -- and
this is not just my idea. I'm getting people from your agency leaking
me information, saying you have to sue on this. I'm getting stuff
saying discovery will reveal an amazing story.
I don't have access until I get to that point to get that information.
You gentlemen do. And I hope you take a really hard look at this, and
I'll be back the next time you have another meeting and we may --
potentially when you do the full committee, and I hope that -- I guess
this is the only place you hear a legitimate debate.
And I read the debate about Farley and I realize your concerns. I'm
just sorry the agency didn't act upon them. And I'm hoping that the
agency and the industry will be a little bit more circumspect in the
future when they decide to regulate or deregulate on the basis of a
probabilistic risk assessment.
I thank you for your time, and hopefully we can get you all out of here
on time.
DR. APOSTOLAKIS: Yes. Maybe we can have a couple questions.
MR. RICCIO: Certainly.
DR. APOSTOLAKIS: Is it possible that all this activity on risk-
informing Part 50 and also the regulatory guides of the last two years,
that it gives perhaps a distorted view of what risk-informed regulation
is all about?
What I mean by that is that the industry has already seen some of the
holes you referred to being plugged by immediate action by the staff
when the PRA said this is bad, like the station blackout rule and all
these things. They came out of the PRA, so they made the regulations
more stringent.
And, in fact, that's why the industry, according to what we were hearing
from NEI up until about two and a half years ago, was really very cool
towards PRA, because they viewed this as a tool of additional
regulations, justifying additional regulations.
So finally they revolted, political situations change and so on. So now
the last three or four years, the emphasis has been, perhaps
inappropriately so, at least for the agency, on finally using these
tools to reduce burden.
So leaving aside for the moment your concern about how realistic the
PRAs are, which I believe is a valid question to ask, perhaps we're
getting a distorted view of risk-informed regulation by looking only at
the activities of the last three years, when, in fact, for the last 20
years, this agency was more than happy to create new regulations.
MR. RICCIO: Chairman Jackson did say -- I remember her saying that this
is a double-edged sword.
DR. APOSTOLAKIS: Yes.
MR. RICCIO: That when we take a good hard look at risk, there is a
potential that we may actually increase regulation.
DR. APOSTOLAKIS: And we already have done this.
MR. RICCIO: And you have already done that in certain instances in the
past.
DR. APOSTOLAKIS: Yes.
MR. RICCIO: My concern is that because of the economic pressures that
are being placed upon this industry to compete and perhaps also I'm
hanging out a little bit too much with the industry, that I've just been
-- all I've been hearing is reduce burden, reduce burden, reduce burden.
And I have little confidence that when an item does come up that could
potentially increase the regulatory burden, that the agency isn't going
to get slapped with having to do a back-fit and, of course, they're
going to be challenged on it.
So in my mind, the reason the industry is interested in this is
basically to drop their costs as much as possible, because it's a
forward-going cost of operation at this point. They already have --
they're getting their stranded costs through the deregulation that's
going on at the state level. So the capital costs are being taken care
of.
They're selling the reactors for ten cents on a dollar in sweetheart
deals. So those things are being taken care of, on the one side.
I feel that when this -- when push comes to shove on something that may
actually need to be increased, that you're going to see this agency
being slowed down by the same industry that wants to deregulate. And I
do feel that there has been, over time, a -- you've made very legitimate
efforts to try to reduce the burden on this industry.
Reducing LCOs by 40 percent, that's a significant chunk. If I reduced
the stoplights on my way to work by 40 percent, I'd get there a heck of
a lot faster, but I wouldn't get there any safer.
When I see that all of this deregulatory effort is being done on top of
what has already come down the pike, and I've been around for these
other reductions in requirements marginal to safety, and some of those
actually were significant to safety, at least according to NRC's
regulatory review.
So my confidence level and the public's confidence level, at this point,
is not very good. The things that help the public -- and when I speak
of the public, we're talking about a small handful of people here in DC
and we're talking about the people that are put at risk around the
reactors. Basically, wherever there is a dump or a reactor, we have a
constituency.
And when I look to those people, the things that concern them are --
like I said before -- the thing like the Haddam Neck ECCS that wouldn't
have functioned for 28 years. How is that captured by your PRA? How
does the cable separation problem at Maine Yankee captured in your PRA?
And I've heard comments from around this table, yeah, let's see a model
fire. I think we're moving in a dangerous direction and I think we're
moving there for the wrong reasons. I believe that the agency has the
ability to re-regulate, but, unfortunately, I think if we continue to
head in this direction, you're going to melt another reactor and we'll
be right back in this room trying to figure out how to put these
regulations back in place, so that whatever remains of this industry
will have a life.
DR. APOSTOLAKIS: So essentially then your criticism or your concern is
that tool that is being used for reducing burden is not mature enough.
It does not reflect the reality or may not reflect the reality out there
at some facilities.
MR. RICCIO: It doesn't reflect reality. The testimony I can pull from
right around this table where that's -- I'm not pulling these from thin
air. These are things that I've learned from listening to this
committee for a decade now, and it's those things that give me pause for
concern.
DR. APOSTOLAKIS: I'm just trying to understand your position. Are
there any comments from other members?
DR. BONACA: I think that we, as a committee, we feel cautious about
these issues, because we recognize them and in recent times we have made
a very specific statement regarding, for example, using risk information
to a larger degree to take a component out of service. We felt that
that was an important step.
Now, I know that that's a burden to the industry. They would have liked
to see it differently, but I think that that's a necessary thing. So
that's -- certainly, the points you're making are important and we have
to be sensitive to those.
MR. RICCIO: And if I could add one more thing. The things that are
going to help in terms of public confidence, transparency and
consistency. This isn't very transparent and I'm afraid once you're
done, it's not going to be consistent, in the least, because of the
voluntary nature of this entire project. You're going to end up with a
regulatory morass when you're through.
You're going to have one reactor being regulated differently than
another reactor, which you may feel is appropriate, but it doesn't lend
to consistency. It wouldn't lend to consistency between regions. It's
not going to lend to consistency within regions, and that's going to be
a problem.
This agency has a hard enough time applying the regs when they're
deterministic and on the books. So when we get to the point of where
you have two different systems operating at the same time, I think
you're going to get into trouble.
I thank you for your time and your consideration.
DR. APOSTOLAKIS: Thank you very much. Is there a question from the
staff perhaps?
MS. DROUIN: The only thing that I would say is that we keep hearing the
word burden. It's unnecessary burden. I think that's a very important
point. We're talking unnecessary burden.
DR. APOSTOLAKIS: He may not think it's unnecessary.
MR. RICCIO: If you hadn't melted a couple of reactors, maybe we could
say it's unnecessary.
DR. APOSTOLAKIS: Thank you very much, Mr. Riccio.
MR. RICCIO: Thank you.
DR. APOSTOLAKIS: Can we go around the table very quickly and have the
members give me advice regarding option three, points in the letter, or
do you want to give them to me in writing?
DR. BONACA: We can give you some thoughts now.
DR. APOSTOLAKIS: You want to give me some thoughts now. Okay. Well,
Mario, you seem to be ready.
DR. BONACA: Just one main thing is that in the presentation we heard,
there is an attempt to go to option three to look at new reactors, new
design, as well as existing reactors, and I feel that this is a task
complex enough that that may be a concern.
I think that this task should have very clear objectives.
DR. APOSTOLAKIS: Perhaps forget about new reactors?
MR. BARTON: At this time.
DR. BONACA: At this time. My feeling is that that's one issue that I
would like to propose to the committee's consideration.
The other one that I want to -- the one is more of a general thought,
that in general, existing designs preceded regulation and because the
industry did not know where regulation was going to go, there were
significant margins being built into existing designs, and those margins
have really paid off in subsequent years, when new concerns came up and
new requirements were imposed. And so regulation followed.
Now here we are in a process of changing regulation to accommodate with
actions in those margins. I think that we have to be sensitive about
that process. That we have to be sensitive enough that we know enough
that we, in fact, can reduce those margins, because there is much more
burden in going in this direction here, where we're affecting a
regulation in a way that will come up -- we discussed here on the LOCA
issue, the ECCS issue.
The ECCS issue could cascade into designs that have now different kind
of vessels, they have lesser piping or whatever because of -- and so
we've got to be very sensitive that we understand these issues to the
degree that we can, in fact --
DR. APOSTOLAKIS: Speaking of understanding and making sure that we know
what we're doing when we reduce margins and in light of what Mr. Riccio
just told us, I have a question for Mary.
Is there anything in the standard that will make the licensees, when
they do their PRAs, undertake a serious effort to really make sure that
what the PRA says is the way the plant is? I mean, I'm not just talking
about the simple walk-downs. I think it will go a long way towards
giving some degree of comfort to members of the public if they see a
systematic approach for checking that the plant, as built -- that what
the PRA analyzes is the plant as it has been built.
Is there something like that in there?
MS. DROUIN: I'm going to answer this from a personal perspective. It
is critical and essential that the standard address that.
My recommendation, and it is in there, whether it's to the level of
detail that it needs to be, can be debated at another time, is what I
personally call the plant familiarization.
DR. APOSTOLAKIS: I think that's the wrong word. We're not talking
about the familiarization.
MS. DROUIN: But we can debate what it is.
DR. APOSTOLAKIS: I understand, I understand.
MS. DROUIN: But the intent of that is getting to that exact point.
DR. APOSTOLAKIS: Speaking then personally as well, I can assure you
that will be an issue that will be raised when this committee reviews
the standard.
MS. DROUIN: I look forward to that, because I think it's critical.
DR. APOSTOLAKIS: And the examples I will use will be Mr. Riccio's
examples. But this is a commitment. Because this has to be put to rest
once and for all. We can't have people, and not just interest groups,
members of this committee or other technical people, feel uncomfortable
with the PRA numbers. We have to show that, yes, we took into
consideration operating history, we did go out of our way to make sure
that what we're modeling is real.
MR. BARTON: But it's still not going to solve the issues that Mr.
Riccio brought up.
DR. APOSTOLAKIS: I don't believe it will.
DR. BONACA: But there is a communication process, Mr. Chairman, that is
fundamental. The point I mentioned before, the examples made refer to a
specific condition where a system will not be able to deliver. That
specific condition may be an extreme condition under all the possible
conditions under which they may operate.
For example, all the NPSH issues have to do with assuming atmospheric
pressure in containment, which implies a fully open containment. There
is no steam there, there is no nothing, and you test to see whether or
not the pumps will recirculate.
Under those conditions, you have cavitation and possibly no
recirculation. So deterministically, you call the system failed.
Now, in all the possible recirculation scenarios you may have to
consider, you will have to consider in the PRA. That would be a minute
fraction of the spectrum of conditions under which you have to perform.
Therefore, you would call the system possibly functional and even
successful. There is a true communication problem also from the
industry, from the staff, in the way we treat conditions where a system
is not operable, but it's functional. We call it failed, because it's
not operable. Inoperable means it doesn't meet the requirements imposed
on the system, okay, are deemed to be functional. And I think it's a
fundamental issue of communication that we have to make.
So from one end, we have to be conservative. From the other, we have
also to be accurate and the communications from deterministic licensing
are not accurate.
DR. APOSTOLAKIS: I agree with you, but we have to also realize that
perceptions are --
DR. BONACA: I understand that. I'm saying, however, that --
DR. APOSTOLAKIS: Rational assessment is not always practice.
DR. BONACA: Yes, but there is a communication issue here that I'm just
presenting.
DR. APOSTOLAKIS: Sure. I understand that, and I'm sure the staff is
becoming more and more sensitive to it. That's, I think, part of the
public workshops, to help everyone communicate better.
So I've got one comment, that maybe they should not work on the
comprehensive revision right now.
Does any other member have --
MR. BARTON: I had that same comment.
DR. APOSTOLAKIS: Anything else?
MR. BARTON: No.
DR. APOSTOLAKIS: Anything else, Jack?
MR. SIEBER: I just don't think we ought to reiterate the absolute
necessity of an accurate PRA.
DR. APOSTOLAKIS: Or the quality. Yes, absolutely.
MR. SIEBER: The standard produces a result that people can have faith
in, we have to understand the way this ASME standard is --
MR. BARTON: You've got to talk into the mic, Jack.
MR. SIEBER: In any event --
DR. APOSTOLAKIS: I understand.
MR. SIEBER: -- the need for a standard is there.
DR. APOSTOLAKIS: I think we will put all this to practice when we
review the ASME standard. Do I hear anything else from my colleagues?
You know my e-mail address if you have any.
DR. BONACA: I just wonder if -- you know, this is an important issue
and a sensitive issue and --
DR. APOSTOLAKIS: This being the quality?
DR. BONACA: This being the presentation we had from Mr. Riccio, and I
wonder if we should have that presentation at the full committee.
DR. APOSTOLAKIS: Invite Mr. Riccio back? What do you think?
MR. MARKLEY: He's welcome to come as a member of the public. He can
request time.
DR. APOSTOLAKIS: Pardon?
MR. RICCIO: I wasn't invited here, so I just showed up.
DR. APOSTOLAKIS: Well, maybe you can think about this proposal by Dr.
Bonaca and request time to address the full committee. You only used 15
minutes. I'm sure we can accommodate that, because I think the
committee should hear your views.
MR. BARTON: I think so.
DR. APOSTOLAKIS: So please consider that. Is there still time for the
next meeting, next week?
MR. MARKLEY: We'll make time.
DR. APOSTOLAKIS: We are meeting next week. So it's up to you. It's up
to you.
MR. RICCIO: Maybe.
DR. APOSTOLAKIS: Maybe in November then, after you give us a chance to
read your report and you wouldn't mind if we disagreed a little bit here
and there.
Anything else? We are adjourned.
[Whereupon, at 3:23 p.m., the meeting was concluded.]
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