467th Meeting - November 5, 1999
UNITED STATES OF AMERICA
NUCLEAR REGULATORY COMMISSION
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
***
MEETING: 467TH ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
U.S. Nuclear Regulatory Commission
11545 Rockville Pike
Room T-2B3
White Flint Building 2
Rockville, Maryland
Friday, November 5, 1999
The committee met, pursuant to notice, at 8:30 a.m.
MEMBERS PRESENT:
DANA A. POWERS, ACRS Chairman
GEORGE APOSTOLAKIS, ACRS Vice-Chairman
THOMAS S. KRESS, ACRS Member
MARIO V. BONACA, ACRS Member
JOHN J. BARTON, ACRS Member
ROBERT E. UHRIG, ACRS Member
WILLIAM J. SHACK, ACRS Member
JOHN D. SIEBER, ACRS Member
ROBERT L. SEALE, ACRS Member
GRAHAM B. WALLIS, ACRS Member
P R O C E E D I N G S
[8:30 a.m.]
DR. POWERS: The meeting will now come to order.
This is the second day of the 467th meeting of the Advisory
Committee on Reactor Safeguards. During today's meeting the committee
will consider the following -- proposed changes to the design control
document associated with the AP600 design; spent fuel fire risk
associated with decommissioning; status of resolution of issues
associated with the design bases information; future ACRS activities;
the report of the Planning and Procedures Subcommittee; reconciliation
of the ACRS comments and recommendations as well as proposed ACRS
reports.
This meeting is being conducted in accordance with the
provisions of the Federal Advisory Committee Act. Mr. Sam Duraiswamy is
the Designated Federal Official for the initial portion of the meeting.
We have received no written statements from members of the
public regarding today's session. We have received requests for time to
make oral statements from representatives of Nuclear Energy Institute,
Northeast Utilities, as well as a member of the public regarding spent
fuel fire risk associated with decommissioning.
A transcript of portions of the meeting is being kept and it
is requested that speakers use one of the microphones, identify
themselves and speak with sufficient clarity and volume so that they can
be readily heard.
Do members have any comments they want before we get into
the day's sessions?
[No response.]
DR. POWERS: Then let's move right into the first topic,
which is proposed changes to the design control document associated with
the AP600. John, are you going to cover that one for us? Thank you.
MR. BARTON: Thank you, Mr. Chairman.
The purpose of this session is to hold discussions with
representatives of the NRC Staff and Westinghouse Electric Company
regarding the changes to the AP600 design control document since the
committee's last review. During the July 1998 ACRS meeting the
committee completed its safety review of the Westinghouse application
for certification of the AP600 passive plant design. The committee
concluded at that time that an acceptable basis had been established to
ensure the AP600 design could be used to engineer and construct plants
that with reasonable assurance could operate without undue risk to the
health and safety of the public.
Westinghouse then issued a design control document that
provides the reference basis for the AP600 design rule. Two months ago
Westinghouse issued a revision to the design control document that
incorporated changes resulting from its final review
This morning members of the NRC Staff and Westinghouse will
discuss these changes with the committee. At this time I will turn
the meeting over to Mr. Jerry Wilson of the Staff, who will introduce
the topic. Jerry? MR. WILSON: Thank you, Mr. Barton. I am Jerry
Wilson with NRR and with me this morning are Mr. Grimes and Mr.
Newberry, representing NRR management.
We are here to request a letter from the committee on two
issues actually, the actual final design certification rule and the
changes to the design control document.
In a letter dated September 28th the NRR sent a copy of the
design certification rule to the committee. The committee had
previously determined in April of this year that it didn't need to
review the proposed rule and wanted to see the final rule after we had
dealt with the comments. We only had one comment on the proposed rule
and it was a non-substantive comment and so the message on the final
design certification rule is that it is basically identical to the rules
that the committee had seen for the ABWR and System 80 Plus designs and
also that is the intent of the Staff, that all three of these rules
should be structured and work in the same manner for all three designs.
Now during the time that we were going through the comment
period on the rule, Westinghouse was continuing to look at their design
and they had, as Mr. Barton said, sent in some design changes in a
Revision 3 dated September 29th of this year. Staff reviewed those
changes and we prepared a supplement to our FSER which I provided to the
committee. that is in a letter dated October 7th and the basic message
in the supplement is that these changes did not affect the findings that
the Staff made in its Final Safety Evaluation Report, but we wanted the
committee to have an opportunity to hear about that and so I am at this
point going to turn the meeting over to Mr. McIntyre of Westinghouse to
present the changes that Westinghouse made and the Staff is available to
answer any questions on their evaluation.
If there's no questions now, Mr. Barton, I recommend we turn
it over to Mr. McIntyre.
MR. McINTYRE: Thank you. Well, it's certainly good to be
back. I realize this is now our 44th meeting and -- an in my life I
like symmetry. It turns out that all the trees in my yard are planted
in squares and lines in nice, easily divisible multiples and now this is
44, so it is nice and symmetric and hopefully this is --
DR. POWERS: Well, 66 would symmetric too.
[Laughter.]
MR. McINTYRE: Yes, it would. Maybe I shouldn't go there.
Also, I want to -- for those who have been asking, yes, it is going to
exist here. This is the -- I don't think this will ever "go
platinum" -- I would be happy, to be quite honest, if we could sell
actually one of the plants but this is one of the requirements we have
to do for the Office of the Federal Register. This is the design
control document on a CD.
Unfortunately it is not word searchable because we ended up
having to scan the thing in for a lot of reasons that I don't want to
get into of where the electronic version of it was but this is the
design control document and it will be available hopefully quite shortly
here for people who are interested.
As Jerry said, we had some changes to the design control
document. We have continued to do more detailed design work. We have
funding to support that from our new owners and we found a couple of
things -- actually found one thing that is part of the detailed design
that didn't work, just absolutely didn't work.
The other thing we found when we were in the throes with the
Thermal Hydraulic Subcommittee of trying to resolve the containment
issue that our focus was on containment pressure, and we got that done
and everybody went "whew" and we moved on and then after we turned in
the design control document somebody said, "You know the temperature
went up too." We said oh -- and that didn't sink in even at that time
and then a little while later somebody said, you know, if the
temperature goes up, the hydrogen goes up, and we said, ooh, darn.
DR. POWERS: Sounds like you need a spray all right.
[Laughter.]
MR. McINTYRE: We have got one, thank you.
DR. SEALE: You're welcome.
MR. McINTYRE: Thanks to you, I think I should rephrase
that.
[Laughter.]
MR. McINTYRE: It just wouldn't be a meeting without that
coming up, would it? And that was something that was in the DCD that
was actually technically incorrect. We have found some other things --
I have a list on my desk of things that we found that we will change in
the design when we do go forth, but those are things that the Staff will
review again.
We will have a chance at the COL stage. If the COL
applicant doesn't reference the DCD exactly as it is here, then they
have to come forth and the Staff has to sit down and go through the
review process so we do have design changes and things that will fall
into that category as we have pushed this forward, but if we find
something that is wrong, I mean wrong, we have got to fix it, so the
hydrogen generation curve is one of the two that we are here to talk
about.
The other is the containment sumps, that the screens as you
recall when we were talking about paint, we put plates over the top of
the containment sumps and we had in our Tier 1 material in the ITAAC the
thing that you have got to meet or you can risk the possibility of an
intervention, and what we put in there was that it extended out 10 feet
from the screen and if you are standing right at the screen with your
back to the wall and look out, indeed it does extend 10 feet but if you
look over about here, there's a steam generator eight feet away.
We said well, the NRC being reasonable guys would understand
that, and then you realize that some inspector could say no, it says
right here in your Tier 1 material that it is 10 feet. You didn't meet
it because your steam generator is there. Figure out a way to do it or
move your steam generator. That could go places that we didn't want to
go.
DR. KRESS: This extension, Brian, was to provide a flow
pattern that would inhibit the debris from getting actually to the
screen.
MR. McINTYRE: So -- and Terry Schulz, one more time for
"the" Terry Schulz, since you have heard from him enough by now --
DR. POWERS: He is a fount of wisdom on this --
MR. McINTYRE: It is his one more time and he has a
presentation on that and he will share that. Not only did we change a
little bit the orientation but we reduced it from being 10 feet above
the top of the screen to be one foot above the screen and we think that
that helps that.
DR. KRESS: Why was it ten feet in the first place?
MR. McINTYRE: We did some analysis work --
DR. KRESS: That showed that was an optimum --
MR. McINTYRE: That showed that that was how far it needed
to be. That was the reason that we -- it wasn't a random based. It
sounds like ten feet is --
DR. KRESS: Well, what it would do is reduce the horizontal
velocity going into the screen --
MR. McINTYRE: Right, and any place that paint was falling
down right in front of the screen and it couldn't just fall and go like
that. It would have to be built up there or travel clear around.
This is the curve that was handed out separately. What it
shows -- this is the old temperatures, new temperatures, that at about
7000 to 8000 seconds, 5000 seconds here, that there becomes a
difference, that we are getting a much higher temperature with the
revised analysis, and it turns out that the reason for that had to do
with the way we modeled the breakflow coming out. It's a mass and
energy issue that we weren't condensing as much. This is one of the
arguments that we had back and forth with the Staff, so we changed our
condensation model out in that time period and obviously if you are not
condensing as much and you are putting more steam in, the temperature
goes from here up to there in the long time.
It does not affect the short-term calculations of anything.
It simply in the long term when we do generate more hydrogen it is still
within the limits of the PARs to deal with and we do stay below the
flammability limits.
We are going to have a presentation on that -- Jim Sejvar is
going to stand up.
DR. SEALE: Are you going to show us how that overlays on
the depressurization valve opening and all that stuff?
MR. McINTYRE: No. The depressurization valve -- this is
out almost in the day time periods. All that stuff opens.
DR. SEALE: Right, all that stuff is back there, yes.
MR. McINTYRE: Way back here -- yes, and this is why it
went -- all of our concentration was looking at these time periods where
the peak pressure was and this was clearly an "oh, my goodness."
With that, I will introduce Jim Sejvar, who is going to
present his presentation on how things did change in the hydrogen
analysis.
DR. POWERS: Does this have any impact on your worst two
hours?
MR. McINTYRE: No.
MR. SEJVAR: My name is Jim Sejvar. I work in the Radiation
Analysis Group at Westinghouse and I am going to try to explain the
impact of these increased temperatures on the hydrogen generation rate
and the buildup inside containment after a loss of coolant accident.
This is addressed in Section 6.24 of the SSAR, which
contains both the design basis accident and severe accident scenarios in
terms of hydrogen generation. This analysis relates to the design basis
accident scenario, which is based primarily on the Reg Guide 1.7
assumptions. There is the basic contribution. Contributors to the
hydrogen are the zirc water reaction.
DR. POWERS: Any significant of the -- just steam effect on
the zinc paint on the side of this containment?
MR. SEJVAR: The zinc paint is included under this item here
so these first three basically don't change -- the initial inventory and
the coolant system, the radiolysis contribution for water in the core
and the sump, and the one that is impacted is in fact the materials
corrosions, which is primarily zinc and aluminum.
So we did reanalyze the situation with these higher
temperatures. Material corrosion rates are a function of temperature --
in fact, they're an exponential function of temperature so these changes
are magnified in the production rates.
The passive autocatalytic recombiners are also -- their
depletion rates are a function of the containment temperature as well as
pressure in the prevailing hydrogen concentration.
DR. KRESS: It goes up?
MR. SEJVAR: I'm sorry?
DR. KRESS: It increased -- the recombiner rate, temperature
and pressure --
MR. SEJVAR: The increased temperature, with increased
temperature their depletion rate reduces.
DR. KRESS: Oh, it reduces. That's interesting.
DR. SEALE: Their rate of getting if you will, is reduced
MR. SEJVAR: Their rate of recombination is reduced, right
DR. SEALE: Right.
MR. SEJVAR: And in terms of pressure it is proportional to
pressure, not proportional but it increases with pressure.
This is based on some experimental data that EPRI provided
us so they basically use that equation.
In the model that we used this shows how discretized the
temperature profile. And, of course, as you saw before, there was some
changes back here, but for our purposes we just, in these low time
intervals, it is not that important. It is basically this long-term
temperature increase that drives the increased production.
DR. WALLIS: What are these two curves here?
MR. SEJVAR: I am sorry. This is the model that we used to
generate the corrosion input. This is the revised temperature profile,
it is based on that curve we just saw, and this is the original. It is
somewhat higher here, but the important thing is back here in the
long-term, this is on the area of 150M below and this hangs up around
220 degrees.
DR. WALLIS: So the change at the beginning is simply for
simplification.
MR. SEJVAR: Yeah, the corrosion of materials is included in
this all throughout the accident, it is just that the time intervals are
so short that the corrosion rates are --
DR. WALLIS: It doesn't imply that your original peak has
disappeared in the revised calculation.
MR. SEJVAR: Not necessarily. In fact, the peak is about
500,000 seconds, then it dies off here. But for the purpose of
modeling, I just assumed that it was constant conservatively.
DR. POWERS: An interesting, but it may not be a pertinent
phenomena binding here is that the kinetics of iodine partitioning in
the atmosphere versus iodine oxidation to the iodate go through a
maximum and just about exactly what their long-term temperature is.
There may be some feature of the physics here that causes it always to
go to that peak in the iodine kinetics at just about that temperature,
just a little over 200 degrees. That's interesting.
DR. SEALE: Could I ask a stupid question? Just curious.
What is the origin of that little pimple out there beyond 100,000
seconds?
MR. SEJVAR: Terry, can you help me on that one? I think he
is talking about this.
DR. KRESS: The bump on the end.
DR. SEALE: Yes, you are out there where -- you always
wonder if there is another bump coming along behind it, bump it up some.
MR. SCHULZ: Terry Schulz from Westinghouse. The water flow
rate for passive containment cooling systems goes through some variation
and various stand pipes are uncovered. We have some long-term, I don't
know if that corresponds with that time or not. There are some places
where we talk about that stand pipe and the water flow drops a bit, and
the pressure reactor goes up a little bit. I would assume that the
temperature would --
THE REPORTER: Something is wrong with your mike.
MR. SCHULZ: Is that any better?
DR. SEALE: Yeah.
MR. SCHULZ: I was not close enough. I was saying that the
stand pipe uncovers and the water flow drops, the pressure tends to go
up a little bit. I think the temperature would also follow that.
DR. SEALE: Okay.
MR. SEJVAR: We tried to present in this overhead the impact
of that higher temperature on the corrosion or the hydrogen that is
input from corrosion. Here I have plotted the total with the new
temperatures, new temperature profile. Here is a previous total,
hydrogen accumulation, with the original temperatures. This dotted line
here is the contribution sources other than corrosion. This bottom
curve was the old corrosion contribution and this is the revised one, so
there is something on close to order of a factor of 2. Corrosion was
secondary in the previous analysis, now it is dominant. And this, of
course, increase translates right up to the level up here.
DR. POWERS: How accurately do you think your modeling
predicts those temperatures?
MR. SEJVAR: I'm sorry?
DR. POWERS: How accurately do you think your modeling
depicts those temperatures and, consequently, the hydrogen accumulation?
MR. SEJVAR: Well, the corrosion rates are based on some
measured data that Westinghouse did way back in the mid '60s plus some
ORNL analyses. They are conservative based on enveloping a lot of PH.
DR. POWERS: What I am interested in is you predicted
temperature, something around 220 degrees F.
MR. SEJVAR: Right.
DR. POWERS: What is the range of uncertainty on that
prediction? And, consequently, what is the range of uncertainty in
these?
MR. McINTYRE: I think that our 220 is a conservative
number, conservatively high.
DR. POWERS: Okay. I guess what I am asking then is what is
the conservative margin in that number?
MR. McINTYRE: I certainly am not the human analyst.
DR. POWERS: Roughly, is it a 10 degree uncertainty, 20
degree?
MR. McINTYRE: My guess, it would be probably more than like
50 degrees. I mean if you go back and you look at our original
calculation, the curve that I had up, that is probably where we thought
it was. And just to get done, we acquiesced.
DR. KRESS: At those times, Brian, your fission products are
probably in your sump, and that is the source of heat into containment?
MR. McINTYRE: It is also still the core, the core is still
steaming.
DR. KRESS: It is still steaming --
MR. McINTYRE: Yes.
DR. KRESS: -- at 20 days?
MR. McINTYRE: There is still decay heat.
DR. POWERS: Yeah, you will still be getting six megawatts
anyway.
DR. KRESS: Yeah, I guess I forgot, AP600 has got a lot of
water to get into the core, even at 20 days.
MR. McINTYRE: Yeah.
DR. KRESS: I had forgotten that.
DR. SEALE: Brian, you dropped your voice when you gave us
the numerical value of that temperature margin, and I was just wondering
if you would pick it up for me.
MR. McINTYRE: It was, if you look at our first, the curve
that I had up, that is probably fairly close to where we would think it
would be on I would call it a better estimate basis.
DR. SEALE: And so that margin is?
MR. McINTYRE: Whatever, I would guess 50, 70 degrees, that
type of a number.
DR. SEALE: Okay.
DR. WALLIS: What do you mean by that, the margin, 50-70
degrees is the difference between what and what?
MR. McINTYRE: Between what we would have -- can you put my
curve back up?
MR. SEJVAR: Sure.
DR. WALLIS: The uncertainty band, is it? Or is it a
conservative module?
MR. McINTYRE: If you look at the new curve, this was just
-- the change from here to here was something that happened as a result
of discussions with the staff, discussions with the Thermal-Hydraulic
Subcommittee on how we modeled the condensation. We couldn't
necessarily support, we didn't have enough data, we didn't have enough
time, all of the above. So we said, okay, we will go -- by changing our
assumption, we will go from here to here
And I think Dr. Powers' question was, well, what is the
uncertainty on this, is it 10 degrees? See, on this calculation it is
not a 10 degrees, but if we think that actual "truth," that is a hard
word, but put it in quotes, that this is probably a more accurate
calculation than that is, but this, we are just trying to bound it to,
if you will, get done.
So this is what we would expect, somewhere down in this
range. This is what we are predicting, somewhere up in that range. So
that is why I would say that is a conservative calculation.
MR. SEJVAR: Again, on this curve I have tried to illustrate
the impact on the hydrogen concentration build-up inside containment
following a loss of coolant accident. And, again, this is the build-up
in concentration based on the revised temperatures and the original
temperatures with no recombination, no removal of hydrogen
We analyzed this with a -- it is called a worst case
depletion rate, which took account of uncertainties in the data and the
measurements and those kind of things, and we have plotted here the
original temperature, the concentrations with the original temperatures
and with the revised temperatures. So, basically, the peak, based on a
worst case depletion rate, goes up from a little over 1 to around 2 in
the maximum, then it decays off as the removal process continues.
And here is a 4 percent, 4 volume percent limit as presented
in Reg. Guide 1.7, the flammability limit.
DR. POWERS: Have you given thought to the issue of how much
more organic vapor you would have available for cooking of the PARs?
MR. SEJVAR: Yeah, that was addressed, and there is a curve
that is not shown here, but it is in the SSAR figures, that includes a
25 percent for catalyst contamination.
There is a also a certain -- we started taking credit for
the PARs at 10 minutes after the accident in these curves, and we also
looked at what would happen if there was a delay because of wet
catalysts, et cetera, and we saw that if we got over 3, 3-1/2 percent,
and assume functionality of the PARs at that point, then basically this
build-up is stopped dead in its tracks and it decays away or to a new
equilibrium.
DR. POWERS: If we calculated realistically the loads on
containment from a combustion of hydrogen, say, between 4 and 5 percent,
what kind of realistic pressure delta would we get?
MR. SEJVAR: I haven't --
DR. POWERS: I bet we would get squat, just nothing.
MR. SEJVAR: It is small, I know that. But I don't know the
number offhand.
DR. POWERS: Yeah, I would think that the burn efficiency
would be so load, it would be a blip.
MR. SEJVAR: Yeah.
DR. POWERS: Four-and-a-half percent is really a very, very
conservative bound on the flammability limits because they are the
upward propagating limits. And the fact that you get a combustion going
on and it disperses the materials to the front so that you don't get
completion burning without some really rapid mixing.
MR. SEJVAR: So, basically, that is what I had here, and
then the results basically indicate that the hydrogen levels remain well
below the flammability limit throughout the accidents. At most, it is
around 2 volume percent, which is about half the Reg. Guide flammability
limit. And, again, this assumes a single PAR is functional, where there
is two global recombiner -- or PARs, and actually four in the plant, in
the containment.
DR. KRESS: You don't have igniters?
MR. SEJVAR: There are igniters, but this addresses a design
basis accident and SER accident associated with the igniters.
MR. McINTYRE: The igniters are non-safety related and they
are for severe accident.
MR. SEJVAR: So if there are any questions? If not, I guess
Terry will discuss --
DR. POWERS: Maybe just a point, I should know the answer to
this, but I can't think of it right now. If you do have a design basis
event, can the operator turn on the igniters?
MR. SEJVAR: Brian, I don't know.
MR. McINTYRE: I think the answer is yes.
DR. POWERS: I mean I guess can and may he?
MR. McINTYRE: Probably, well, would. It depends, there
would be something written in the emergency operating procedures and
response guidelines to address that.
DR. KRESS: Just in case the PORs don't work right.
DR. POWERS: Yeah, I mean if I am in there and I am at least
worried about hydrogen accumulation, and they have got these magic
catalysts that I don't know anything about. I don't do anything, I just
sit there, I am going to turn on an igniter so I can least know I have
done something positive. And I mean I can't imagine it would hurt
anything.
DR. KRESS: It wouldn't hurt anything.
DR. POWERS: Well, I worry about things like, gee, it may
turn all the iodine aerosols into iodine gas. But, in fact, so what? I
mean it is going to come up to an equilibrium, or a steady-state level
of iodine concentration anyway, so what difference does it make?
MR. SEJVAR: Thank you.
DR. POWERS: I mean that is the last of my worries.
MR. SCHULZ: My name is Terry Schulz and I work in
Westinghouse in the plant design, fluid systems area. And as Brian
mentioned, we found a problem in the containment recirculation screens,
in the plate
Let me just summarize quickly the situation with these
containment recirculation screens. We feel the AP600 has a very robust
situation here. First of all, for insulation, we use only metal
reflected insulation inside containment where it can be affected by a
break and, as a result, we will generate no fibrous debris in a LOCA
situation. In addition, from coating debris point of view, that if it
is generated, it will settle out before it reaches the screens.
First, the coatings that we use inside containment, down on
walls and floors, and surfaces and structures, is considered non-safety.
However, we are procuring the coating as a safety coating, and the
reason for that is to increase the chance, the probability that it will,
in fact, stay where it is supposed to stay. However, the application
and inspection will not be handled as a safety operation.
MR. BARTON: Terry, you can buy the best paint, but you
don't apply the safety grade paint properly, you are going to have a
problem.
MR. SCHULZ: That's true. That is possible. However, just
because it is not safety doesn't mean it will be misapplied. Our
utility partners have -- would like to avoid the what they consider
burden of inspecting initially and then throughout the life of the plant
to meet the safety guidelines.
Now, we can debate, and we may have different opinions on
how likely, you know, is this to fail or not fail, and I agree with you,
if it is misapplied, it probably will fail. However, the other side of
the coin is that we feel that failure can be tolerated in this design.
DR. POWERS: I have noted recently in the trade press of the
coatings industry that a lot of jurisdictions are imposing restrictions
on coating the people can apply because of the volatile organic
compounds that get liberated into the atmosphere. Clearly, California
is probably the most aggressive, but a number of other states are
following California's lead. Does that have any impact on the selection
of coatings for this plant?
MR. SCHULZ: I don't know. The coatings that we are
planning on using inside containment are inorganic zinc, which will be
the primary coating on the containment surface. It will also be used as
a primer under steel surfaces that are top-coated with an epoxy
DR. POWERS: All of the zinc primers that I know of have a
lot of methyl ethyl ketone in them, and that is what these jurisdictions
are trying to get -- to avoid putting up in the atmosphere. I don't
know the details. I mean surely there must be someway you can use a
methyl ethyl ketone based paint in these jurisdictions, but I am just
curious whether it is having an impact of the choice of coatings.
MR. SCHULZ: I don't know.
DR. KRESS: The concern with methyl ethyl ketone is health
effects, right?
DR. POWERS: You know, you would have to ask somebody more
knowledgeable that I, whether it is a smog issue or a direct health
effect, or what it is, but it is causing --
DR. KRESS: The ozone layer maybe.
DR. POWERS: Yeah, it is causing some real problems in the
pigments and coatings industry, either problems or opportunities. They
are having to up their level of technology because you get people that
just won't let them liberate these volatile organic compounds. And
California is really getting very, very difficult on this issue because
they see it as one of the major sources of smog generators left in the
Los Angeles Basin and in the San Francisco area.
DR. KRESS: That just means they can't sell them in states
that prohibit it. But is there an issue of conversion of iodine to
organic --
DR. POWERS: Oh, I mean I can't imagine this affecting it.
I mean there is another organic from another things to do that.
DR. KRESS: You have got already, you don't have to worry
about this.
DR. POWERS: I wouldn't worry about that. I am just curious
if these new rules, that really are -- do they not have any affect on
us?
DR. KRESS: It may be a marketing issue, you know.
MR. McINTYRE: I think the effect that you might see is
somewhere like lacquer paints, you can't buy lacquer paint to paint a
car anymore for exactly that same reason. And it might affect
long-term, down the road, the availability of these paints, but right
now it is extremely common, and it was Penn DOT uses to paint the
bridges over the Pennsylvania Turnpike.
DR. POWERS: Everybody uses this. That is why the states
are focusing in on it so heavily is everybody uses it.
MR. McINTYRE: Yes.
MR. SCHULZ: Most of inorganic zinc I think will be applied
in factories. The containment will be --
DR. POWERS: I see what you are saying.
MR. SCHULZ: Panels will be built pre-bent and assembled, --
not assembled, but in a factory, and will be coated in a factory. Now,
when they are welded together, there will be a little portion.
DR. POWERS: Yeah, that's true.
MR. SCHULZ: So that may help the situation, it won't
eliminate.
DR. POWERS: Sure, I mean I could imagine how you would do
it. Then you would have a facility at the plant that would allow you to
do the painting and handle the off-gassing and keep the state happy.
MR. SCHULZ: Yeah.
DR. KRESS: Your stage 4 depressurization valve comes off of
the hotleg into containment?
MR. SCHULZ: Correct.
DR. KRESS: Is it aimed so that it doesn't -- or has it got
protective screens to keep it from impacting your reflective insulation?
MR. SCHULZ: It is aimed, they are, of course, in the loop
compartments. They are at a horizontal discharge.
DR. KRESS: They are horizontal.
MR. SCHULZ: And it is, the first thing it will impact is
the wall, containment loop compartment wall. So it would not directly
impact insulation.
Again, it really ends up being a no-never-mind because of
factors like it is the metal reflective insulation. We have at least
three hours, in most cases more like five hours between the time of an
accident and before we start recirculation, a very different situation
than current plants, which are 30 minutes or something like that. So
there is a long time when we are not recirculating.
We have much deeper float-up levels. Instead of five or six
week, or a little bit more, we have more like 24 feet. The screens are
very tall, and they are located well above the bottom of the screen, as
well as above the floor, so like two feet. So things, debris that might
have settled has a very hard time --
DR. KRESS: To lift it up.
MR. SCHULZ: To get up. Recirculation flow rates, without
spray, with gravity recirculation, or even with our pumped RHR, which is
not safety, even if we run that, which the operators are told to do, the
flow rate from that pump is less than the typical low head SI pumps you
have in current plants. So the recirculation flow rates are a lot less.
We also have these protective plates which are a unique
feature of this design to protect debris from getting into the screens.
So, the bottom line is that if the coatings fail, we can tolerate that.
DR. WALLIS: I asked you about debris settling, is it
presumably based on it being denser than water?
MR. SCHULZ: Yes.
DR. WALLIS: Now, if there are chemical reactions going on,
I don't know what they may be, and they are bubbles being formed which
are attached to these particles, then the particles can float up because
they become buoyant. A bubble plus a particle is a buoyant particle.
And I just don't know what the chemistry is that is going on there, but
if there are chemical reactions that produce gas, they can float the
particles. So your argument about settling out would no longer perhaps
be as strong.
MR. SCHULZ: Well, again, the paint is procured as a safety
paint, so we know the material. We know that if this material is
applied properly, under strict safety guidelines, it will stay in place.
DR. WALLIS: Well, I was just -- I am just looking at the
lower half of your slide here.
MR. SCHULZ: Okay.
DR. WALLIS: But you talk about settling.
MR. SCHULZ: Yes.
DR. WALLIS: And I was just saying, I don't know what the
chemistry is in this.
MR. SCHULZ: Chemistry of what?
DR. WALLIS: Whatever is on the floor and in the water. If
there is gas produced, it can make the debris buoyant.
MR. SCHULZ: And I think what I am trying to say is I think
that the material on the floor, if there is something there, is most
likely coating debris. I don't know what else would be in abundance in
there.
DR. KRESS: Yeah, your metal reflective is going to be too
big.
DR. WALLIS: Is there any gas produced in this mixture of
stuff?
DR. POWERS: Just suppose that you shoot off plates of the
zinc painting, it goes into the sump. Subsequently, basically, so you
get a reaction with the zinc to form zinc oxide and a little hydrogen.
Okay. And he is asking, okay, if that bubble adheres to the zinc, which
it surely will, it will make the zinc particle buoyant. Now what?
DR. KRESS: My guess is those reactions go so slowly at
these temperatures, you will have to wait months before you can --
DR. POWERS: I mean the amount of volume he has to get to
levitate his particle is pretty small.
DR. KRESS: Still, but it takes months.
MR. SCHULZ: To levitate one particle, yes.
DR. POWERS: Well, I mean each particle is going at the same
rate. I mean it doesn't have to do one and then do the next, and then
the next, they are all going simultaneously. I mean I think the answer
you have got a big tall screen, and you can tolerate of lot of floating
particles is I think your answer.
MR. SCHULZ: Yes.
DR. WALLIS: These are all qualitative arguments. I don't
know what one needs to do to make it convincing, but a tall screen has
got to be relative to the job it has to do, and some analysis of how
many particles are buoyant and so on. And I don't know what analysis
you may have done of that sort.
MR. SCHULZ: We have not analyzed you hypothetical situation
there. It seems --
DR. WALLIS: If you could give an answer that the gas, there
is so little gas produced, that you could take that gas and adhere it to
the particles, it still can only float some small amount or something.
The Particles don't stay at the bottom of the solution when
a lot of gas is being evolved.
MR. SCHULZ: I would think that would be dependent on how
much gas is being evolved, very much so.
DR. WALLIS: Yes. But if you think of the settling tanks at
Hanford, those waste tanks at Hanford, they've been doing this for a
generation. A generation evolving gasses, doing various things to the
particles.
DR. KRESS: They've got a better chemistry to allow the
gasses.
DR. POWERS: Well, as I said, the zinc would work really
well on that. I think zinc would react to produce gas.
MR. SCHULZ: Yes. Now, most of this --
DR. POWERS: I mean, to me it's got some screening area that
a fairly simple calculation --
DR. KRESS: -- a basic solution with the zinc oxide produces
that battery.
DR. POWERS: Yes, sure.
DR. WALLIS: Well, it may be that you ought to make some
calculations to support this argument that debris really does settle
out, which considers the possible gas production.
DR. KRESS: The real problem, Graham, is trying to start
from production to the debris off of the paint and the transport of that
debris into the containment and fallout into the sump. You've got
almost an impossible modeling job
That was attempted at one time, and it was just so
uncertain, the results, that you almost have to view this as one of
those cases where you can't analyze it away. You just do a defense in
depth by putting screens and making your thing enough.
DR. WALLIS: How big is "big enough"? You'll get all those
arguments. I suspect you probably will get some floatation, and you'll
probably get a water line. You'll get some kind of particles on the
surface with bubbles. Check under the screen, wherever the surface is.
I don't know --
MR. SCHULZ: The surface is ten feet above the top of the
screen, okay.
DR. WALLIS: It's way up above the screen.
MR. SCHULZ: It's way above the top of the screen. So if
something floats that's above the screen --
DR. WALLIS: So it's while it's going up or coming down that
it gets into the screen.
MR. SCHULZ: Yes. The other thing is, that most of the
inorganic zinc in containment is on a containment surface, and that is
considered safety, so that the application inspection of that coating
is, is safety related.
DR. WALLIS: When you did your hydrogen that we just saw,
the chemical reactions created quite a lot of hydrogen. Are those the
corrections we're talking about here?
MR. SCHULZ: Jim?
MR. SEJVAR: Yes. The hydrogen analysis included the
contribution from the paint
DR. WALLIS: And it was not negligible? You had quite a
contribution from chemistry in that plot you showed.
MR. SEJVAR: Yes.
DR. WALLIS: That suggests to me that there's a large amount
of hydrogen evolution to make these hypothetical bubbles we're talking
about. I just think someone ought to look into it. It's, the argument
that it settles out is not complete.
MR. SCHULZ: Jim, the corrosion is of zinc -- it's the zinc,
inorganic zinc paint is really the, not the epoxy that's generating the
hydrogen.
MR. SEJVAR: Right. Basically, the covering is excluded.
It's just the zinc primer or whatever you have is considered. And
that's basically -- it'll assume a barrier by the epoxy for the zinc to
corrode and evolve hydrogen in the containment
It seems like if you're, you're double-counting, if we take
that zinc that's produced by the corrosion on the surfaces through this
barrier or whatever, and now we're putting it in the sump, it would seem
like it would be more inclined to remain in the water if it's down in
the sump.
DR. WALLIS: I don't understand.
MR. SCHULZ: It still can bubble up through the water,
presumably, and get to the atmosphere, get into the atmosphere from --
MR. SEJVAR: Right, but my point was that if we take, if we
take this contribution of zinc and corrode it at a rate that's a thin
layer and it evolves hydrogen rapidly, if the zinc is washed into the
sump where it evolves hydrogen, wouldn't the hydrogen be more inclined
to just remain in the sump water and bubble up or whatever.
DR. WALLIS: But that's where you don't want it because it's
making the particles buoyant
DR. KRESS: Yes, but the fraction of the debris that gets
into the sump is probably small and it's a small contribution of
hydrogen.
DR. WALLIS: All of these arguments are very qualitative,
aren't they? And someone should make a convincing analysis
MR. SCHULZ: I think you could also hypothesize, if you
think this is a lot of hydrogen being generated, how does the epoxy stay
connected to the steel when it's got a layer of zinc in between? But
yet it does. Qualified paints. Okay, there's a qualified paint system
that you take inorganic zinc and apply it to steel, and you top-coat it
with epoxy, so you've got now zinc trapped in between steel and epoxy.
And that's a qualified coating and it's supposed to stay in place if
it's applied properly and maintained properly
DR. KRESS: Let me give you a simple calculation to make.
You've got this curve of your hydrogen generated due to corrosion of
mostly zinc, which gives you the gas rate of production per unit time.
And you know what the product endpoint is going to be; it's called zinc
oxide. You know what its density. Find out, at that rate of hydrogen
production, it all stayed with the unit mass of the zinc oxide, how long
would it take to make that buoyant to get above the density of water, or
below the density of water? That'll tell you whether you have months
before this is buoyant or whether it gets buoyant rather fast. And
that's a simple calculation that might answer the question. You can do
that on the back of an envelope. In fact, I could have done it here if
I'd have had the numbers. You might try that and see if it works.
DR. WALLIS: But the fact that there is this hydrogen
contribution to the containment, which is a rather large volume of gas,
which is a few percent by volume, indicates to mere there's a lot of
hydrogen.
DR. KRESS: Yes, but there's a lot of zinc in there. And
that's the, it's the amount of, it's the amount of hydrogen per amount
of zinc.
DR. WALLIS: Ah. The volume of zinc compared with the
volume of the containment is very small.
DR. KRESS: Um hmm.
DR. WALLIS: It doesn't take much gas
DR. KRESS: I'm talking about -- but, but the ratio you're
interested in is the volume versus the mass. It's mass per mass that --
DR. WALLIS: Yeah, but your volume, the volume per unit mass
for the gas is 2,000 times what it is for the particle. And it's
hydrogen, so it's even more. 10,000 times. It's a huge factor by
volume. So anyway, I don't think we should continue qualitative
arguments if it's an issue then that should be resolved then by proper
calculation.
MR. SCHULZ: What I was going to show you next was the
actual interference that we discovered. As Brian mentioned, in the loop
compartment, our screen is located in this corner. And in front, we
really had no problem in maintaining the ten feet. But over in this one
side, we had an interference with the reactor coolant motor that
extended down. Actually we had no problem with the steam generator
because that's above.
The original idea was to use an existing radiation shield
plate, which was located right above the loops. And that forms the, a
walking surface so the people, when they enter the loop compartment over
here, they can walk around. And the shield plate reduced the radiation
exposure to the operators. And we intended to use that shield plate as
a dual-purpose protection for the screen. Now you can see the outline
of that plate. Unfortunately, we needed to cut out in the center for
the hot leg which came up --
DR. WALLIS: Excuse me -- you're looking down on something?
MR. SCHULZ: Yes.
DR. WALLIS: Because I thought to start with, it was a
cross-section vertically, which didn't make any s3ense.
MR. SCHULZ: I'm sorry. This is a plan --
DR. WALLIS: It's stupid.
MR. SCHULZ: This is a plan of the loop compartment. You
see the two reactor coolant pumps, which are vertical, extending down
below the steam generator, which is up above the reactors on the top of
the page. So this is the, the center line of one of the two loop
compartments
So we had this interference in this area. We also had some
other difficulties in trying to make this radiation shield plate also
perform the duty of the, protecting the screen. So instead of that, we
decided to provide a dedicated plate that would be located right on top
of the screen.
Now one of the other things you'll notice is the screen
shape changed. And we ended up doing that because there was another
interference with a pipe that was located, that was running around
inside of the loop compartment. Now that didn't cause us any problems
relative to the DCD or the ITAAC because we could reshape the screen to
provide exactly the same surface area and keep the bottom two feet off
the bottom of the floor and meet all of the requirements, although that
did aggravate the interference problem because --
DR. WALLIS: How course is the screen, can I ask what's the
mesh size on the screen or how course or fine --
MR. SCHULZ: It's the standard PWR type technology. There's
a rough grating, which is floor grating, which is maybe an inch and a
half wide, two or three inches long type openings. Vertical, major
bars. And that's on the surface. And then behind that is a fine
screen, which I think is like one-eighth of an inch minimum openings.
So this is what we're proposing and did in the DCD is to
reduce the dimension on the side. Now, that by itself tends to reduce
margin in the settling, ability of particles to settle before they can
get to like this corner of the screen. So to compensate for that, we
also changed our commitment on the height of the plate
In the ITAAC and the DCD we said the plate could be as much
as ten foot above the screen. We did that because we were trying to
make use of this existing show plate, which happened to be
nine-point-something feet above the top of the screen. And we wanted to
allow ourselves the ability to use that. We also know from our
calculations that when you lower the plate to the top of the screen,
that especially the upper part of the screen, maybe from halfway up, is
much better protected because the particles almost have to go horizontal
to get there. Whereas, if you have a plate that sticks out ten foot,
the settling rates don't have to be so low to get into even the top of
the screen. So committing to a plate that is like no more than one foot
above the stop of the screen significantly increases the protection of
the screen by the plate.
DR. WALLIS: Your trajectories of the particles are assumed
to be vertical?
MR. SCHULZ: No. There's a horizontal flow
DR. WALLIS: If I put a piece of paper shaped object in
water, it goes around and it doesn't go down straight, it can go off --
if I throw the piece of paper in the air, it can go off quite a lot to
the side
MR. SCHULZ: It would tend to flutter
DR. WALLIS: Yeah, but it may even go off like a paper
airplane.
MR. SCHULZ: If you shaped it like a paper airplane, yes.
DR. WALLIS: No, I mean it doesn't go straight down. It
does go off.
MR. SCHULZ: Yes.
DR. WALLIS: The distribution, and, you can just do an
experiment. So you assume they go straight down?
MR. SCHULZ: Within the dimensions of the particles involved
and the distances involved, there's no additional motion, net motion.
DR. WALLIS: You assume they go straight down.
MR. SCHULZ: Fluttering of particles is possible, but it's
not considered credible that it'll continue going in one direction.
With randomly shaped particles, they're not going to behave like
airplanes.
DR. WALLIS: You've seen leaves falling from trees?
MR. SCHULZ: Yes.
DR. WALLIS: Well, the spread out. They don't go straight
down.
MR. SCHULZ: I, I don't ever think I've seen one fly
straight.
DR. WALLIS: You've seen some fly straight, yes.
MR. SCHULZ: I haven't.
DR. WALLIS: Not all of them, but some of them.
MR. SCHULZ: I don't ever think I've seen one fly straight.
They go in circles, they fly places --
DR. WALLIS: But it depends on -- there's a diffusion in
some of them. By the random processes go --
MR. SCHULZ: A few of them is no problem. Again, we have --
DR. WALLIS: It's just a question of, there is a phenomenon.
It looks as though you've assessed it by guesswork rather than analysis.
And I don't know if it's important.
MR. SCHULZ: We have done analysis on settling of particles
getting to the screen. We have not considered flying of particles
flying toward the screen. No. We don't think that's credible. At
least, any significant amount of particles.
DR. KRESS: My suspicion is you get an equal number going
away from the screen as towards it and it would balance out.
DR. WALLIS: It doesn't matter. No. All that matters is the
ones that go to the screen.
DR. KRESS: No, no. If you assume all of them are going
straight down.
DR. WALLIS: Then none of them would get to the screen
because of the shield plate.
DR. KRESS: Well, no, they follow the trajectory of the flow
when they get past the shield screen.
DR. WALLIS: Which is very slow.
DR. KRESS: Yeah.
DR. WALLIS: So that's not the problem.
DR. KRESS: It's not slow compared to the flutter.
DR. WALLIS: The thing is, if you drop particles on this
shield plate, you'll get a statistical sort of distribution. Some of
them will go in towards of the screen; a few will reach it. I don't
know if it's significant or not.
DR. KRESS: Well, I think the assumption is that they follow
the flow.
DR. WALLIS: It just looks to me like liberal arts
engineering rather than analysis.
MR. SCHULZ: I don't know how you'd ever analyze that. I
don't think it's possible.
DR. KRESS: You'd have to know the shape and size of the
particles. It'd be impossible to analyze. You'd have to do it
experimentally. That'd be the only way to do it.
MR. SCHULZ: And even that, you could always argue, did, how
representative of the experiment is --
DR. KRESS: Right. You'd never know what the debris is
going to actually look like.
MR. SCHULZ: -- accidents, and how, how do the particles
detach
DR. WALLIS: Well, if you don't know how to do it, that's,
that doesn't mean to say it's not a problem.
MR. LOBEL: Can I make a comment? This is Richard Lobel
from the Staff. There is, there are some proprietary calculation not
related to this but related to the general subject of accumulation of
debris on screens that Westinghouse has done calculations where that was
considered, based on some work -- I can't give you a reference off of
the top of my head. But they did consider that effect. And their
analysis included that, and the debris still pretty much on a whole
followed the direction of the flow. It was a larger flow than what
we're talking about here, but generally it didn't seem to make that much
of an effect.
DR. WALLIS: Yeah, we're talking of going to something like
six feet sideways while it falls twenty feet. That sort of thing we're
talking about.
MR. SCHULZ: It's, it's following in this case, what --
well, if the bottom of the screen is thirteen feet above, below the
plate; not -- again, the plate is on top of the screen.
DR. WALLIS: Yeah, so it's --
MR. SCHULZ: This screen here actually is like ten feet high
DR. WALLIS: So it goes, yeah, but it goes sideways, and
then it gets buoyant. It comes up. So it could get on the floor below
the screen, twenty feet. So we're talking about whether a leaf falling
from a maple tree twenty feet up there may or may not wander six feet to
the side in its descent. I don't think that's incredible.
MR. SCHULZ: I don't understand -- I question your numbers.
I don't know where you're getting feet. There's no twenty feet that's
important here.
DR. WALLIS: I'm sorry. I got twenty feet because you said
deep float-up levels: twenty-four feet. Maybe I don't know what that
means. It says --
MR. SCHULZ: Well, that's where the --
DR. WALLIS: -- 13 feet
MR. SCHULZ: That's where the water level is.
DR. WALLIS: 2 feet off the floor. So, from this plate to
the floor is how far?
MR. SCHULZ: It is 15 feet.
DR. WALLIS: 15 feet. Okay, so then 20 was too big an
estimate
MR. SCHULZ: And the bottom of the screen is 13 feet below
the plate. So I think the 13 feet is, is the important number. And
it's at least 7 feet to get to the corner; not 6 feet. And to get to the
back part of this screen, it's really 10 feet
DR. WALLIS: Okay.
MR. SCHULZ: So it has to move 10 feet horizontally.
DR. WALLIS: That's right.
MR. SCHULZ: And to fall 13 feet to get to the bottom of the
screen. And you don't really threaten the screen until you've plugged
most of it. So now you start talking about, it has to settle only a
foot or two over a distance of 10 feet. And you're okay. So it's hard
for me to imagine --
DR. WALLIS: So in terms of sort of expert engineering
judgment, it doesn't seem to be a problem, which means unsupported by
some sort of calculation procedure that's -- that may well be right. I
just don't know.
DR. KRESS: Well, the old screen that was in the thing has
already been approved by the staff as a certified part of the design.
And all we're dealing with now is a new screen. And we should ask the
question, is the new screen better or worse than the old one? And I
think the judgment could be that it's better in the sense of stopping
the debris. I don't know if we want to revisit the certification basis
of the old screen in the first place.
DR. WALLIS: So the argument is --
DR. KRESS: My view is, is the new screen better or is it
worse than the old one? DR. WALLIS: Putting in the screen plate is the
new part?
MR. SCHULZ: No, the screen plate has always been here.
DR. KRESS: The screen plate's always there. It's just --
MR. BARTON: It's a new design screen.
DR. KRESS: -- an entirely different shape. It's a new
design.
DR. WALLIS: A different screen is what we're talking about?
MR. BARTON: It's new plate
DR. KRESS: It's a new plate. The screen is about basically
the same. It changed a little.
DR. WALLIS: What is the new plate? It's that --
MR. SCHULZ: What is different is this portion. Not this
portion here. What's new about --
MR. BARTON: Is the shaded area.
MR. SCHULZ: -- is the shaded area back at this 7 feet used
to be 10 feet.
MR. MCINTYRE: Terry, put up the old screen, and I think
that would be helpful
MR. SCHULZ: This is what was approved
DR. KRESS: The screen was much higher also.
MR. SCHULZ: Yes. And so the plate was ten foot higher
DR. WALLIS: But it's in there because of interference.
MR. SCHULZ: Right. But in terms of what was approved.
DR. KRESS: That was approved.
MR. SCHULZ: Was a design --
DR. WALLIS: The impossible was approved.
MR. SCHULZ: Well, what we did was a sensitivity analysis to
try to bound such uncertainties as your raising and to look at this
average settling rate type data and say that, you know, we think it's
going to settle at this rate, but if it settles at four times, eight
times, or whatever that -- does the stuff get to the screen, and how
much of the screen can it plug? And in this design, the settling rates
have to get something like four times, five times what we think they
would be in order to get most of the screen plugged and to maybe
threaten operation.
In the new proposed design --
DR. WALLIS: Let me ask you -- I'm sorry --
MR. SCHULZ: Can I just finish that, this one point, because
this is a measure of the improvement in terms of the sensitivity, that
with this design, even assuming that the particles are all coming from
the short side, that in order to threaten the screen -- i.e., plug most
of it -- the settling data has to be like 15 times the base settling
rate, so -- to plug most of the screen. So that is -- and the benefit
from that is coming from having the screen being very close to the top,
or the plate being very close to the top of the screen.
DR. WALLIS: What's happening here is this debris and water
falling on the plate?
MR. SCHULZ: No. The plate is underwater.
DR. WALLIS: It's under water.
MR. SCHULZ: It's -- in this design here, the top of the
screen is 9 feet or so underwater. Debris could be settling through
water on top of the plate but there's no water cascading on top of the
plate.
DR. WALLIS: That was my question. If it was, if there was
a waterfall off the edge of the plate, that would change things. You
don't have that? You don't? MR. SCHULZ: So our, in summary, we made
two corrections. One of them was to eliminate the interference and
shorten the dimension of the plate on the side. Not in front. And the
second, which we didn't have to do strictly speaking, because having a
lower plate was within the DCD and ITAAC. But in order to compensate
for a possible reduction in margin here, we committed to having a plate
being close to the top of the screen. And the combination of this
actually increases the margin in the design.
MR. SIEBER: Is the plate that you're putting in there
coated?
MR. SCHULZ: What the DCD says is that no non-safety
coatings will be used on the underside of that plate or on any
structures that are sort of in the umbrella of that plate, down to the
bottom of the screen. Our intention right now is not to use coatings;
it's to use stainless steel material. But that's not a commitment in
the DCD. The only commitment is that if we were to use coatings there,
they would have to be safety-related, completely.
MR. SIEBER: Thank you.
DR. WALLIS: How high is the pile of debris on the shield
plate?
MR. SCHULZ: How high is the pile of debris on the shield
plate?
DR. WALLIS: Presumably it's there to catch debris.
MR. SCHULZ: If it --
DR. WALLIS: How big is the pile?
MR. SCHULZ: I don't know. The -- what's --
MR. MCINTYRE: I think the answer to that is there's no pile
because we don't think that the paint really comes off.
DR. WALLIS: Oh, no, no. You're making the assumptions
about it coming off that you're making. Aren't you making some
assumptions about the paint coming off?
MR. MCINTYRE: We're not saying it will. We don't think it
will. So Brian's bringing up a sort of probability-related argument --
DR. WALLIS: You don't want to answer the question, going
back to some other thing.
MR. SCHULZ: We don't have a failure probability of the
paint coming off. I mean --
DR. WALLIS: If it comes off, how big is the pile on the
shield plate? Not very big, is it?
MR. SCHULZ: I don't think so. What you're -- presumably
where that coating could come from is the walls in the loop compartment.
I don't know if I -- trying to think of how far those walls go up. But
basically what's above here is just the wall surface, the vertical wall
surface of the loop compartment, which goes up a limited distance
DR. WALLIS: I guess it's very small
MR. SCHULZ: I would think so. I would think so. Even if
all the coating on this loop compartment wall surface came off, I don't
think it would be very much.
DR. WALLIS: I'm just asking these three or four questions
I've been asking because it seems to me they're obvious questions that
occur to me, and I would have thought they would have occurred to you
guys and you'd be ready with the answer.
MR. SCHULZ: Well, do you have a concern about that, or?
DR. WALLIS: Well, I don't know how big the effects are, so
I don't know.
MR. SCHULZ: Okay.
DR. WALLIS: I was sort of expecting you to be right up
there with the answer.
MR. SCHULZ: Are there any other questions?
DR. KRESS: What is the depth of the coating on the wall?
MR. SCHULZ: The wall is a steel module, so there'll be an
inorganic zinc primer with an epoxy topcoat to it.
DR. KRESS: Again, on the inorganic zinc, it's probably
something like on the order of a 64.
MR. SCHULZ: It would be relatively thin. The epoxy would
be presumably somewhat thicker than that. I don't know what the numbers
are exactly.
DR. KRESS: To answer his question, you take the ratio of
wall surface area to the top surface area and multiply it by the
thickness of the thing and you've got that depth.
DR. WALLIS: Whatever it is -- it's six inches or something?
MR. BARTON: No.
DR. WALLIS: One inch?
MR. BARTON: You mean, the depth of the coating?
DR. WALLIS: No. It's what's on the plate if it catches
everything that falls on it.
MR. BARTON: Oh
DR. WALLIS: So, you know, you could have a pile of junk on
this plate.
MR. SCHULZ: There could be some there.
DR. WALLIS: It's not just a pile of junk; it's probably
making hydrogen. So it's alive, and it wanders around. It's -- you
know, it falls off the edge of the plate.
MR. SCHULZ: So it falls off, into the water.
DR. WALLIS: Yeah.
MR. SCHULZ: It's just gonna sink.
DR. WALLIS: It falls as a plume, which has a diffusion to
the side. It doesn't go straight down. Any plume of -- if you throw
mud into water, it doesn't go straight down. It falls in a plume and it
has a spread, just like any turbine
Well, no
MR. SCHULZ: But yeah, there's a factor in the density of
that stuff that you're throwing into the water
DR. WALLIS: A turbinal plume falling spreads at an angle of
ten degrees or something like that.
MR. SCHULZ: How much it spreads has got to be related to
densities. Particles size. Small particles, real small particles are
not an issue because they'll go through the screens. So we have to be
talking about particles that are relatively good sized, 8th-inch type
particles, which are maybe not what you're thinking about
DR. WALLIS: Well, they're all there in all kinds of sizes.
MR. SCHULZ: I understand that there will be small particles
there, but the small particles are not a threat.
DR. WALLIS: The big particles probably diffuse more because
they have this fluttering, which increases their random motion sideways.
MR. SCHULZ: That's one effect, and I agree it's gonna be
random, but I don't think it's gonna stay in one direction. The
particles aren't gonna stay slanted.
DR. WALLIS: No, it's not all. It's --
MR. SCHULZ: Any --
DR. WALLIS: -- unrealistic
MR. SCHULZ: Any one of the particles is not going to stay
at a slanted angle.
DR. WALLIS: All the maple tree leaves don't fall to the
side, but a certain percentage don't go straight down; they go off to
the side.
MR. SCHULZ: These particles aren't going to be shaped like
leaves though.
DR. WALLIS: Well, I'm -- forget it.
DR. SEALE: It's more like cornflakes. Big cornflakes.
DR. WALLIS: Cornflakes will flutter.
DR. KRESS: But once again, we should ask all these
questions with the --
DR. WALLIS: If you drop a bucket of cornflakes into a
swimming pool, you will get a distribution on the floor --
DR. KRESS: Oh, there's no doubt about it.
DR. WALLIS: -- which shows that they spread quite a lot to
the side.
DR. KRESS: You're absolutely right, there's no --
DR. WALLIS: Maybe 20 percent --
DR. KRESS: You're right.
DR. WALLIS: -- they fell.
DR. KRESS: You're absolutely right. There's no doubt about
it. And it would have been an interesting question to ask with the
original question to ask with the original --
DR. WALLIS: The only thing that surprises me is that these
questions don't seem to have been addressed as much as I might have
expected. You're the experts. We've had ten minutes to think about
this.
MR. BARTON: Any other questions of Terry? If not, we'll
turn it back to the staff.
MR. WILSON: Thank you, Mr. Barton. As I said before, the
Staff has reviewed all of the documentation changes that was in-house
made in revision 3. And also this design change that Mr. Schulz has
been discussing. Our evaluation of the design changes in the supplement
to the SER that we sent to Committee, on page 6-1. And our findings are
that these changes have not changed the findings that the Committee made
in its original FSER.
DR. WALLIS: Did you ask any of the questions that I asked?
MR. WILSON: I'm going to turn this over to Mr. Lobel and
ask him to speak to that, please.
MR. LOBEL: No.
[Laughter.]
DR. KRESS: I think the question ought to be parsed in two
different ways. One is, did you ask these questions in reviewing the
change? Or were these questions asked in the original approval of the
first screen?
DR. WALLIS: Well, if they'd been asked in the original
approval and they turned out to be significant, then one would have to
ask what was the effect of the change on the answers to these questions.
So I have to assume the questions were never asked. But I'm not sure
that that's right. It's just that that would be my presumption.
DR. KRESS: I don't remember anybody asking.
MR. LOBEL: The questions were never asked.
DR. WALLIS: Is this a problem? Does, is this a problem
that someone who hasn't thought about this at all seeing it, can ask
questions -- I don't mean trivially. I mean, they are phenomenon which
occur. And I believe they do, which don't seem to have been asked
either by Westinghouse or by the staff. I find that a little
surprising.
MR. LOBEL: The data that was sued by Westinghouse for the
settling rates came from data that was used in, by a licensee for review
that concerned the quality of the paint and the containment. It was
actual settling rate data. Several licensees have done experiments with
paint, dropping paint in front of screens where the flow and the
settling rates -- well, most of the paint settled before it got to the
screens. Almost all of the paint settled before it got to screens
The paint particle has a fairly high specific gravity
compared to water. We didn't consider bubbles bubbling up and holding
the paint up. I think maybe I missed something, but something that I
didn't hear addressed in the discussion was that there's a flow towards
the screen. It isn't just a diffusion of, of these particles spreading
out with no horizontal component to the flow. The flow is lower with
the Westinghouse AP-600 than it is with light-water reactors. But still
there is a flow component too. And that was considered in their
calculations. But we didn't ask the question about bubbles suspending
particles
I think you have to consider that there's a lot of surface
area here. It would take an awful lot of bubbles to hold up enough
particles to be significant. If it did hold the bubbles up all the way
to the surface, that's not a concern. You've got plenty of screen area
below the surface.
DR. WALLIS: all you need is the volume of gas which is a
few times, three or four times the volume of the particle. The mass
involved -- zinc coating is not that great, so you don't need much
hydrogen to float all the paint.
MR. LOBEL: Well, if it floats it --
DR. WALLIS: It goes up and down. It goes up and down -- it
goes up to the top and some bubbles release and it falls down and it
gets buoyant again. As it makes some more hydrogen, it goes up --
MR. LOBEL: If you keep making that much hydrogen. Like I
say, we didn't ask the question.
DR. WALLIS: No, my sense is that these are probably not
problems.
MR. GRIMES: This is Chris Grimes. I recall from the --
there was an event at Barsebeck that caused us to go back and reflect on
the research work that was done, which enacts safety issue A-17. That
generic safety issue established all the empirical evidence that was
used to establish approach velocities for suction screens. I don't
recall the empirical data ever looked at gas production as a means to
float the debris
But after Barsebeck, we realized that the greater threat to
plugging the screens was not so much how much coating or other kinds of
debris that could be generated from the basic design, but rather, it was
material control because of things like workers' suits and other larger
objects that get left inside containment and float around. And for that
reason, a lot of other countries are looking at backflow procedures so
that they don't have to be concerned about whether or not they've
accounted for every square inch of material
The modeling that I've seen of different debris kinds is,
it's probably not even liberal arts engineering because you don't know
how the paint's gonna break up. You don't -- you know, if the paint
comes off in one large sheet, then no matter how low your approach
velocity is, you potentially could wrap the suction screen. So for that
reason, we tend to look at these things more as material control issues
and emergency operating procedures, as opposed to trying to model the
debris that's going towards the sump
MR. BARTON: Any other comments or questions? Hearing none,
I'll turn it back to the Chairman.
DR. POWERS: Thank you. WE are now scheduled for a break,
so why don't we recess until 10:15.
[Recess.]
DR. POWERS: Let's come back into session. Our next topic
is the spent fuel fire risk associated with decommissioning. And Dr.
Kress will lead us through this issue.
DR. KRESS: Thank you, Mr. Chairman. This subject of the
fire risk to the spent fuel pools is going to be discussed by the staff,
but I understand it's a work in progress, so it will mostly be a status
report. We're not being asked at this time for a letter, but if we
detect that they may be going in their wrong direction with the status
report and we're going where they didn't. We'll find the right on.
DR. POWERS: I remind the members that our boss, the
Commission, has explicitly for guidance on this particular topic.
DR. KRESS: We'll also hear, in addition to these
presentations from the staff, we'll hear presentations from NEI to give
us the industry report. And there are a couple of concerned, interested
citizens that will make presentations also.
The issue is that spent fuel pool fires appear to be the
dominant risk for permanently shut down plants, and the question is, how
long do you have to be a caretaker for the spent fuel before you can
pretty much decide the risk is at an acceptable level without much
caretaking. And this caretaking involves cooling of the spent fuel pool
and seeing whether or not it's drained out, or if the water's there.
And this depends on the, things like the heat level, and if you lost
cooling, how long would it take to heat up to temperatures that would
cause a run-away oxidation, and then basically have the impetus to
release a fission product. So those are the kind of issues we'll hear
to day
And it's also a risk question. Just what actually is the
risk and when, at what -- it's a risk that varies with time, which is
something we don't usually face. And the question is, at what time is
this risk low enough that we can start doing away with some caretaking
provisions
With that introduction, I'll turn it over to John Hannon,
who's the branch chief of the plant systems branch.
MR. HANNON: Thank you. Good morning. The staff
appreciates the opportunity to come here this morning to brief the ACRS
on our progress with the Technical Working Group on Decommissioning.
We are in month 8 of an approximate 12-month effort that's
been supported by a multidisciplinary team, with members from all 3 of
the technical branches in DSSA and with input from the Division of
Engineering, Office of Research, and other specialty areas such as EP
and Security
Diane Jackson works for me, and she is going to be giving
the brief this morning. She's the lead engineer on the Technical
Working Group, but she'll be supported by members on the team that are
in the audience, as necessary. So let me turn it over to Diane now to
conduct the briefing.
MS. JACKSON: Good morning
DR. POWERS: Good morning. We'll get you wired in.
MS. JACKSON: Good morning. Is that good?
DR. POWERS: You'll have to say something, so I --
MS. JACKSON: Oh, is that sufficient?
DR. POWERS: Is that good for the reporter?
MS. JACKSON: Can the reporter hear? Okay. Okay. As
introduced, I am Diane Jackson. I'm a member of the Plant Systems
Branch and a Technical Working Group leader. Our presentation today is
going to be on the Technical Working Group study. It's a broad-scope
study that's looking at spent fuel pool accidents, and its associated
risk at decommissioning plants.
We set out a plan at the beginning that we're following.
Our work towards our final assessment is in progress at this time. At
the same time of finishing our final technical work, we're also
addressing stakeholder comments. And the results of this will fold into
being incorporated into rulemaking
Just a short background on decommissioning. When plants
began decommissioning, it was found that most of the operating reactor
regulations were not developed considering the transition from operating
power reaction operations to decommissioning, and that many of the
regulations were not necessary for decommissioning plants that just had
fuel in their spent fuel pool
The staff has been issuing exemptions on a case-by-case
area, a case-by-case basis in many areas, such as emergency
preparedness, safeguards, and indemnification. However, we found that
this isn't a very efficient process for regulation. To remedy this, the
Commission has directed the staff to issue rules specifically for
decommissioning plants
At the time the Commission gave this direction, there were
five rules in development. These rules were combined into one
rulemaking package, and we were given direction to risk-inform to the
extent possible the whole package
DR. KRESS: Is there, has differentiation been made between
"decommissioning" and "decommissioned" past-tense? Are those two
different things?
MS. JACKSON: Yes there are. Most -- plants that -- well, if
you let me defer to the project side to give you a very good definition.
MR. HUFFMAN: This is Bill Huffman. I'm a project manager
in NR. The process of decommissioning starts with a certification to
permanently shut down and removal of fuel from the reactor.
DR. KRESS: This is what, five years?
MR. HUFFMAN: It actually starts when they send us the
certification after the fuel's been permanently removed from the
reactor. It can extend for many years depending on the financial
situations and incentives for the licensee. They can be in safe-store.
They can incrementally decommission, or they can actively decommission
very rapidly, depending on availability of waste sites, finances, other
plants on-site. So the question of decommissioning is the entire
process. The end of the process is a license termination where they
have basically restored the site and turned it over for commercial or
public use.
DR. KRESS: Thank you.
MS. JACKSON: For the Technical Working Group consideration,
we're only dealing with the decommissioning process
DR. KRESS: How many plants are currently going through
that?
MS. JACKSON: I believe there's 18 in the decommissioning
process right now, at different phases of it
Just the last bullet on there. It was shortly after the
Commission gave us this direction that the Technical Working Group was
formed. And this was about March-April timeframe of this year. And we
set off on a path to look at spent fuel pool accident risk
Our output from our activities is to provide a technical
bases on spent fuel pool accident risk to help with the development of
this integrative rulemaking, to provide guidance for interim exemption
criteria during the rulemaking activities over the next several years --
DR. KRESS: And is the Working Group itself doing a risk
assessment?
MS. JACKSON: Yes. Yes, and I'll -- that's coming up in a
few minutes.
DR. KRESS: You're going to tell us who's on this working
group? Who the members are.
MS. JACKSON: Oh, certainly. Would you like them to stand
up as well?
DR. KRESS: No
[Laughter.]
DR. KRESS: I was just wondering what branches they come out
of and what their expertise was at PRA.
MS. JACKSON: In the PRA area, we have from the DSSA branch
of probability, we have Glen Kelly, Mike Cheok. We have advisory role
of Gareth Parry.
DR. KRESS: Never mind. You've said enough.
MS. JACKSON: Okay.
[Laughter.]
MS. JACKSON: One of the other missions that the Technical
Working Group was given was to identify any areas that came out of our
study, that gave us, there was enough large uncertainty in that area
that maybe we should consider additional work.
The expectation of the study is, would be that it
would be able to generically applied to all plants such that
site-specific analyses would not have to be done.
DR. SEALE: Excuse me. Could I ask --
MS. JACKSON: Certainly.
DR. SEALE: Specifically, who from Research is involved with
your Working Group?
MS. JACKSON: In the Thermohydraulic area, it was Chris
Boyd. And in the area of consequences, it was Jason Chaperall.
DR. SEALE: Okay.
MS. JACKSON: We have one other role for research, and we'll
be talking about that in a minute. But we're having an independent
review currently done of our draft report and our members of Research or
contractors through Research who are performing that, and that would be
Nathan Siu and Dr. Bob Kennedy.
DR. SEALE: There are no specifically Materials people
involved?
MS. JACKSON: No. No. Gutan Bagchi is looking at the
seismic area, and he's from the Division of Engineering
DR. SEALE: Yeah.
MS. JACKSON: And he provides support if there's any
material questions.
DR. SEALE: Okay.
MS. JACKSON: We started out looking at existing information
on spent fuel pool accidents and spent fuel pool risk, and we found that
a comprehensive review of both areas didn't exist for decommissioning
plants. The most extensive information that was done was in support of
Generic Safety Issue 82, which was Severe Accidents in Spent Fuel Pools,
which was done in the mid '80s.
DR. KRESS: And that was for operating?
MS. JACKSON: That was performed for operating plants,
exactly. We found some very useful information out of those reports
that could apply to decommissioning plants. However, we felt due to
some of the operational changes since the '80s and also the different
systems and different level of personnel that were at decommissioning
plants that didn't quite apply directly to decommissioning plants, so we
felt that there was a void in information.
Our preliminary study contained two key areas. One was a
decay time estimation based on existing thermohydraulic coat analysis,
and that was to give us the window of vulnerability for zirconium fire.
DR. POWERS: I guess I'm confused on what you mean -- the
decay time based on thermohydraulic analysis.
MS. JACKSON: Okay. In Generic Safety Issue 82, they did a
lot of studies using S fuel 1 at Sandia National Lab to look at how long
would have to be shut down so that your decay was sufficient enough that
you wouldn't have enough decay heat to heat up your fuel in your cloud
to reach zirconium oxidation. And they used thermohydraulic codes to
look at air flows and to see what kind of cooling mechanisms you'd have
if you only had cold fuel.
DR. KRESS: Natural convection v. transfer coefficient.
DR. POWERS: I presume that the zirconium oxidizes at any
temperature above absolute zero.
MS. JACKSON: But there's a point at which, that the heat
added from your decay, from your decay heat of your fuel, that it will
start become very rapid and you won't be able to stop the temperature
excursion. And that will take you to ignition. And that' the window
we're looking at for thermohydraulic analysis. What does that window
for temperature force the lower threshold for that?
DR. POWERS: I mean, what you're looking for is some point
where the heat generated is exactly balanced by the heat removed?
MS. JACKSON: Yes
DR. POWERS: Okay.
MS. JACKSON: And that has to at some level that you can
stop the temperature excursion from oxidation.
DR. POWERS: Okay.
DR. KRESS: That heat was coming from the oxidation process
itself.
MS. JACKSON: Yes, it's an exothermic reaction.
DR. KRESS: But the decay heat is just a way to --
MS. JACKSON: To get you --
DR. KRESS: -- incrementally get that oxidation up to a
level --
MS. JACKSON: Let me -- I have a back-up slide on this, and
it seems like a good enough time to go to it.
If I can pass these around.
DR. SEALE: It's an igniter.
MS. JACKSON: This is a graph from NUREG-0694, which was one
of the reports done in support of Generic Safety Issue 82 and it is
showing us decay time versus maximum clad temperature. As decay heat
goes down as time increases and so your maximum peak clad temperature
goes down.
DR. POWERS: I am going to have to interrupt you.
MS. JACKSON: Sure.
DR. POWERS: Members should be aware that I am listed as an
author on this particular document and though I can honestly say I don't
remember a thing about it --
[Laughter.]
DR. POWERS: -- I had to look it up to make sure -- I am
listed as an author on it.
MS. JACKSON: Okay. We have been reading a lot about this
report.
DR. WALLIS: What does the word "minimum" mean in the axis
there?
MS. JACKSON: Just given uncertainties -- I think it was
just a lower level of how much decay time that they thought you would
get -- if you had this much decay time, this is the temperature you
would get to, so given uncertainties that was your lower bound.
DR. WALLIS: So minimum is needed?
MS. JACKSON: Yes --
DR. WALLIS: Minimum is needed because it is a bounding
calculation?
MS. JACKSON: Joe, would you want to, would you say it was a
bounding calculation?
MR. STAUDENMEIER: I don't know why they listed it as
minimum decay time. Joe Staudenmeier, Reactor Systems Branch, NRR.
I don't know why their choice of axis label, but it is -- to
get to that temperature --
MS. JACKSON: Decay time --
DR. WALLIS: It takes a certain time. It's just --
MR. STAUDENMEIER: It's just decay time so I don't know why.
I mean --
DR. WALLIS: Presumably the authors of the report put the
word "minimum" there for some reason.
MS. JACKSON: Well, there is some uncertainty in the
calculation --
MR. STAUDENMEIER: I don't think that was considered --
MS. JACKSON: You don't think --
MR. STAUDENMEIER: -- or why it was minimum.
MR. HOLAHAN: This is Gary Holahan of the Staff.
I suspect what it covers is things like how much fuel is in
the pool. If there were a lot less fuel than, you know, or different
configurations, so I think the analysis was done for a relatively
conservative configuration and then other configurations would have had
longer times.
DR. KRESS: That would affect just the heat transfer
coefficient --
MR. HOLAHAN: Well, radiative --
DR. KRESS: -- fuel doesn't matter --
MR. HOLAHAN: Radiative heat transfer and stuff like that to
adjacent fuel --
MR. THROM: My name is Ed Throm, with the Staff. I believe
in that report what they were looking at is trying to develop a
temperature criteria so if you said I wanted to maintain the temperature
below, for example, 600 degrees celsius I would have to have a minimum
decay time based on a certain racking configuration to assure that I
would not exceed that temperature.
That was the temperature that Diane was alluding to a little
earlier, and you can see from these curves that at about 800 degrees
centigrade the oxidation process really takes off, so if you were to
look at a temperature criteria, for example, this type of curve would
tell you the minimum decay time you would need to assure yourself, if I
could use that word, that you would not exceed a certain temperature, so
that is kind of the simplicity of the terminology "minimum decay heat"
from that particular report.
DR. KRESS: Could you tell us what these parameters are --
square 3 inch hole, cylinder 3 inch hole?
MS. JACKSON: Sure.
DR. APOSTOLAKIS: What does the curve mean, first of all?
Can you explain the figure?
MS. JACKSON: Sure. We are looking at how much time you
would need given that you want to keep your fuel below a certain
temperature, and just from the general shape of the curve as you go up
this, the solid line, is increase in temperature due to decay heat.
The dashed line is when you get more or a dominant effect
for temperature increase due to oxidation, so you can see that somewhere
around 600 to 800 degrees oxidation is taking over as your driver for
temperature, and that you can't stop your temperature increase after a
certain point.
The various lines are different --
DR. APOSTOLAKIS: Could you point to the screen?
MS. JACKSON: Oh, I'm sorry.
DR. APOSTOLAKIS: Thank you.
MS. JACKSON: Sure. The various lines show different spent
fuel storage configurations -- the very old ones were open frame, later
on they went to cylinders, then they went to squares and the hole is
the, the hole in the orifice at the bottom, the orifice in the bottom
that would allow air to go down and then come up to cool your spent fuel
assembly, so that makes a difference in how much cooling air you would
get if you lost all your fuel -- your water.
DR. POWERS: The authors of this document were looking at
heat transfer versus an oxidation reaction apparently and the oxidation
reaction they had in mind was the oxidation of zirconium clad on the
fuel, which presumably had been exposed to a burnup of up to 33 gigawatt
days per metric ton.
We now have fuel going into spent fuel pools at much higher
than that, and whereas the zirconium hydride in 33 gigawatt day fuel is
probably dispersed, we can have localized concentrations of zirconium
hydrides in the higher burnup fuel.
Do we understand how that material reacts in an oxidizing
environment?
MS. JACKSON: I don't think extensive or any studies have
been done on that since Generic Safety Issue 82, but the higher burnup
is one of the reasons that we feel that the conclusions that came out of
there, the actual values for decay time that are acceptable don't
exactly apply to the decommissioning plants or the plants that we
believe -- the plants as they are configured in the future, so we think
current spent fuel pools and future ones will be somewhere on this part
given that they are a little higher density in racking and that their
burnup is higher, so they are going to have to wait longer to get to a
decay time.
DR. WALLIS: Are these calculations based on some sort of
heat transfer coefficients and flow resistance coefficients and things
like that?
MS. JACKSON: Yes.
DR. WALLIS: Typically there is a fair amount of error or
uncertainty in the heat transfer correlations particularly if the exact
geometry and range of groups and so on has not been investigated
experimentally, so what sort of uncertainty are these predictions
subject to?
MS. JACKSON: I don't know that particularly. I don't know
if they put that in the report.
MR. STAUDENMEIER: Heat transfer and flow is laminar flow
and heat transfer in the bundle so yes, heat transfer and flow
coefficients probably have an uncertainty in the range of 10 percent.
There is no real uncertainty analysis done on it at all, but I would say
that is probably the smallest part of the uncertainty in the whole
problem because you have this whole building temperature and ventilation
problem that has a lot higher uncertainty in calculating that.
DR. APOSTOLAKIS: Now your previous slide said that you are
determining the decay time, so would you tell us how you do that from
this figure?
MS. JACKSON: Well, given if we want to say for this
particular burnup and everything if we want to keep the temperature of
the clad below where oxidation would take over, we would say, you know,
it would be 600 --
DR. APOSTOLAKIS: Let's pick one curve and do that.
MS. JACKSON: Okay -- well, let's pick this one.
DR. APOSTOLAKIS: Okay.
MS. JACKSON: Since that is the closest one to what we
have --
DR. APOSTOLAKIS: Sure.
MS. JACKSON: -- today. We would want to keep temperatures
below a certain level that oxidation wouldn't take over and we could --
DR. APOSTOLAKIS: Before the line becomes dashed.
MS. JACKSON: Right, that we could say you won't get the
temperature excursion that will take you to a zirconium fire, so we
would have to then go when you get to 600 and down here how many days
does that take? And we would say that is your window of vulnerability
to a zirconium fire. Okay?
DR. APOSTOLAKIS: Okay.
MS. JACKSON: But like I said before, today was somewhere --
DR. APOSTOLAKIS: And this time is fairly well known? There
is no uncertainty about it?
MS. JACKSON: As Joe just mentioned, there is some
uncertainty in it.
DR. APOSTOLAKIS: Some means it is minimal or --
DR. KRESS: It is uncertain.
DR. APOSTOLAKIS: Less than significant or --
DR. KRESS: That is the question. There's uncertainties in
the reaction --
MR. BARTON: A couple days or a couple years --
DR. KRESS: -- rate. There's uncertainties in the heat
transfer coefficient.
DR. APOSTOLAKIS: So if I read the figure, at 600 it is
about 800 days?
MS. JACKSON: Could be.
DR. APOSTOLAKIS: Now that could be -- 500 would be a
thousand or it could be just a few days up and down? Do you have any
idea what the order of magnitude is?
MS. JACKSON: Joe is going to have to answer.
MR. STAUDENMEIER: I think it is more in the range of years,
like the timeframe of the uncertainty. It's just things on how you
configure the fuel in the fuel pool if you concentrated all the hot
bundles together in one spot like some plants have done. That is a lot
worse than checkerboarding them with hot bundles next to like long decay
bundles which have a lot less power.
A lot of these times are driven by the assumptions that you
make, like these times are computed in a method that pretty much assumes
the building is not there at all, that you get perfect ventilation from
the outside, so that the uncertainty is in the range of years.
DR. APOSTOLAKIS: Actually that confuses me but -- 800 days
is what? Two and a half years?
MR. BARTON: Something like that, yes.
DR. APOSTOLAKIS: And now you are saying the uncertainty is
years? What does that mean?
MS. JACKSON: Yes. Given that these are --
DR. APOSTOLAKIS: It could be all the way down to zero?
MR. STAUDENMEIER: No.
MR. BARTON: It would go the other way.
DR. APOSTOLAKIS: It would be what, 10 years?
MS. JACKSON: Any maybe that is why they chose this to be a
minimum one. They think it would be extended farther, probably not
less, and this is one of the reasons that the Commission says we should
risk inform this process -- to do a thorough hydraulic analysis for a
generic spent fuel pool is difficult -- to be kind.
You know, it depends highly on how the fuels in the pool,
how -- you know, Joe had mentioned how much spacing you have around the
well, a lot of different things that it is hard to capture this in a
generic area, and that is why we are looking at these types of analyses,
just to give us a window to say, you know, when are we concerned about a
zirconium fire, now let's see what type of initiating events and
scenarios would affect the risk in that window.
DR. APOSTOLAKIS: But didn't you say earlier that you would
like to resolve this in a generic way and now do plant-specific risk
assessments? Isn't that contradicting what you just said -- that it is
really plant specific.
MS. JACKSON: The whole study -- the whole study, yes,
should apply generically and we not going to pin it down to a number of
days for every plant. You know, there is a range that we are looking at
and we're trying to estimate what that window of vulnerability is.
Currently we think the window is somewhere in the order of three to five
years.
So we will take -- we think within a five year period is
when you might be vulnerable zirconium fire. Given that five year
window, what do we know in the risk area that could tell us something
about what we -- how likely do we think a zirconium fire will really
happen.
DR. APOSTOLAKIS: So if the figure tells me two-and-a-half
years, then you will consider something like five to account for the
uncertainty?
MS. JACKSON: And given different things like higher burnup,
denser racking, things like that, yeah.
DR. SEALE: In a way, the reality of the situation is that
concerns for things like housekeeping are going to be more dominant than
anything else. A little bit of Saran Wrap that would interfere with the
airflow getting into these fuel bundles is probably a bigger uncertainty
in terms of what temperatures -- how much cooling you are going to get
and what temperatures you are going to arrive at than these things even.
DR. WALLIS: These started off covered with water?
MS. JACKSON: Yes, spent fuel pools.
DR. WALLIS: And the waters were somehow lost?
MS. JACKSON: Yes.
DR. WALLIS: Then it takes some time for them to dry out and
all that sort of thing. And this is way down the road, no one has put
any more water in there, and it is just hanging there in the air?
MS. JACKSON: Right. Or it assumes a severe accident that
would --
DR. WALLIS: Drain the pool.
MS. JACKSON: Drain your pool, and you wouldn't -- you might
not be able to put water back into your pool.
DR. WALLIS: And this is a steady-state analysis, this
happens pretty quickly after that?
MS. JACKSON: It depends on how far out that you have decay
time. Once you drain your pool, you might, you know, if it is just
after shutdown, you might have just a few hours. After a couple of
years, you will have several hours for the decay heat to be able to heat
up to that point.
DR. WALLIS: And you could put a fan in there and things
like that?
MS. JACKSON: Theoretically, you could if you got a
volunteer to put one in there
DR. KRESS: This fuel is stored in, is it --
MR. BARTON: Spent fuel pools.
DR. KRESS: Yeah, I know that. They are vertical and if
they are BWRs, they are in the shroud that is around it, and if they are
PWRs, --
MS. JACKSON: Right. And the Bs, they are in secondary
containment, and PWRs, they are in an auxiliary building.
DR. KRESS: They are outside the containment.
DR. WALLIS: It sounds like they are inside containment of
this dry fuel.
MS. JACKSON: For PWRs, they are not.
DR. KRESS: PWRs are outside.
MS. JACKSON: They are just in a building.
DR. WALLIS: So there is dry fuel hanging there, and you not
sure because you have got uncertainties about whether it going catch
fire or not, and someone says, what do we do? It sounds like a really
interesting situation.
MS. JACKSON: And for areas such as emergency preparedness
regulation, that you look at severe accidents, that is one of the
reasons why we think the study is important to do.
DR. WALLIS: You can't flood it with non-combustible air, I
mean gases?
MS. JACKSON: A spent fuel pool is about 40 feet deep, 40
feet wide, and 20 feet. So we are looking into those type of mitigation
--
DR. POWERS: A big time leap.
MS. JACKSON: It is difficult to assure that that type of
environment can be maintained.
DR. SEALE: I think housekeeping is the issue.
DR. WALLIS: Make sure it never happens.
MS. JACKSON: That is what we want. Okay. The other key
area of our study is the risk assessment. Now, we started out with a
broad set of initiating events. We did receive some initial criticism
that all these events were not necessary to look at, but since this is a
risk assessment, we wanted to start with all the initiating events,
consider them all, and analysis should tell us which ones are
significant and which ones aren't.
Since the beginning of the study, we have had significant
stakeholder interest in it. We had planned on doing our independent
review prior to the release -- or the staff work prior to the release of
the study, but given that we had so much stakeholder interest, we did
release our preliminary work as a draft study, which you were provided.
We also thought it could benefit the staff to release it
early and that we could maybe gather comments from our stakeholders and
perhaps get additional technical information from industry, given that,
you know, they are the ones out there running their decommissioned
plants every day, they could tell us what they are doing, and would be
able to help refine our assessment a little better.
We have held several public meetings to meet with our
stakeholders during the preliminary part of the study, and after the
issuance of the draft, and that included a two day workshop that we had
in July, during which we received a lot of comments and additional
comments from subsequent teleconferences we have had and correspondence
we have had.
In the workshop, we found that the major industry concern
was that the risk analysis didn't give sufficient credit to operator
actions and plant conditions. And we have been working to remedy that.
This list is a list of some of the top stakeholder comments
we have gotten in many different areas.
DR. POWERS: Let me understand, you have in this, in your
document you have created some event trees
MS. JACKSON: Yes.
DR. POWERS: And you have an event tree associated with
seismic events, heavy load events, some loss of coolant, loss of heat
sink kind of events.
MS. JACKSON: Yes.
DR. POWERS: Then you walk through the trees and they are
like classic trees.
MS. JACKSON: Yes.
DR. POWERS: And you have some probabilities of each one of
the nodes on these trees. Where do the probabilities come from?
MS. JACKSON: We tried to take them from -- there was
NUREG-1275 that looked at spent fuel pool accidents at operating plants.
We looked at them to try and find the ones that would apply to a
decommissioning plant, not all of them would. We looked at additional,
you know, what was the current standard for human response actions that
was used in PRAs. Is there any other input you can --
DR. APOSTOLAKIS: Are you going to show any event trees?
MS. JACKSON: Today, no, we were not prepared to talk about
them.
DR. KRESS: They are in the document, George.
MS. JACKSON: They are in the document. At this point, we
released our draft study, but we are really beyond our draft study. We
are trying to focus our concentration on finishing and refining that
assessment and addressing our stakeholder concerns to finalize our whole
assessment in the next month or two.
So, to look at some of those numbers, I think would be a
disservice at this point because they are changing. But we have gotten
information from industry. We have gone out to other experts to try and
refine that.
Okay. I do want to talk about several areas, though, that
we have --
DR. APOSTOLAKIS: Some of them are pretty high, actually,
some that you used.
MS. JACKSON: And we were kind of surprised by that as well.
We thought, you know, maybe these numbers would all be low and that is
what our assessment would show us and we would be done.
DR. APOSTOLAKIS: I am talking about the inputs. The
operator recovery actions and so on. You are using probabilities of 1
in 10 that they will do the wrong thing, right? That is a pretty high
number.
MS. JACKSON: Glenn, would you care to respond to that?
MR. KELLY: Well, I would have to know exactly -- my name is
Glenn Kelly with the staff. When we did the risk assessment, some of
the events that you are looking at there perhaps are ones that are
included in the dependencies associated with previous things that had
happened in the event tree. Without knowing specifically what it is
that you are referring to, it is difficult for me to respond to that.
But I think you will find that the -- where we tended to end up and
where we were running into problems, we were in an area where the
methodology and the data really didn't cover events that were taking
multiple days to occur. And so we did the best with the kind of
information that we had available.
We have subsequently been working with some world class
experts to attempt to expand in this area and to identify what things
have to happen at the plant and with the utilities themselves in order
for us to have confidence that the human error probabilities are low.
We don't believe that it is valuable, or if we could come up with exact
numbers, we would love to do that. I think that is extremely difficult
for long-term events. We think it is much more profitable to go ahead
and develop the criteria that are necessary for us to feel that the
human probability is low without necessarily coming up with an exact
number.
If we could come up with an exact number, we would, and we
have been looking at that
DR. APOSTOLAKIS: I am not asking for exact numbers. Did
you do an uncertainty analysis, do you have distributions? I don't see
--
MR. KELLY: No, this entire risk assessment was performed in
about two-and-a-half months. We had a very tight schedule and we had to
do a lot of things in parallel rather than sequentially. And with that
understanding, we went ahead and worked with point estimates rather than
distributions of uncertainty.
MS. JACKSON: Okay.
DR. KRESS: What were the endpoints of your event trees?
MS. JACKSON: The endpoint was the frequency of fuel
uncovery, so the top of the fuel. And although that is not quite
equivalent to initiation of a zirconium fire, we thought it was a good
approximation for analyses point, that if you got that low, then --
DR. KRESS: Probably an hour away from --
MS. JACKSON: Right. You are going to most likely get
there.
MR. KELLY: This is Glenn Kelly. You are more than an hour
away from when you are -- the water is at the top of the fuel.
DR. KRESS: Before you boil off the water.
MS. JACKSON: Right.
MR. KELLY: Right. The reason why we made -- the assumption
I made when we did this was that once you got below about three feet of
water above the fuel, that you would be unable to effectively recover it
from inside the reactor, the reactor building or the spent fuel pool
cooling building because the dose rates would be so high that,
effectively, you are not going to be able to send anybody in there.
We went ahead and had INEL perform a calculation to
determine those kind of dose rates, and we found that if you had -- the
fuel was entirely uncovered, that you are talking about dose rates in
rem in the tens of thousands of R per hour. So we felt that that is
probably not an area where we would want to be sending people in to make
recovery.
DR. SEALE: That is not where you want to go.
MR. KELLY: Right.
DR. POWERS: There might be some specific people you would
like to send in there.
[Laughter.]
MR. KELLY: So my assumption was that, you know, that
recovery would not be effective. And I talked to people about whether,
you know, we could stand off at a distance and just shoot a fire hose in
there or something as the building is burning down, and they felt that
that wouldn't necessarily be very effective, because once you start a
zirconium fire, the dose rates could be considerable for anybody
standing close by.
So, from our standpoint, although it is the timing and the
numbers are not exact, we felt that it took so much time to get to -- to
boil down to the point where you -- or to have the inventory be lost to
the point where you were uncovering the fuel, that the additional credit
that you could take in human reliability space was minimal compared,
because it is relatively flat at this point, where you are talking about
being days into the event, that we felt that additional credit you were
going to take for the heatup time, or the additional time to get the
fuel heated up was something that we felt was going to be in the noise
compared to all the other things that were going on.
MR. HOLAHAN; This is Gary Holahan. I think Glenn expressed
exactly how the analysis was done and the logic for it. However, I have
asked them to go back and look at the difference between the two
endpoints they have picked, just to be sure that, you know, we are not
biasing our results by picking an endpoint of top of fuel versus zirc
fire. And if we can get a little additional author our insights on that
matter, I think we will cover that in between one way or another.
DR. POWERS: I think I would be very, very cautious about
going farther on this top of the fuel uncovery, because you are going to
get to a point that you have to go in and start arguing chemical
kinetics, if you go farther than that. And I think you would have a
very hard time persuading anybody with the current experimental database
that you understand the kinetics, chemical kinetics that affect the fuel
combustion here.
In your document, there is a lot of talk about what the
ignition temperature is of zirconium and whatnot, and it really may not
be zirconium ignition temperature you have to worry about. You may have
to worry about nodules of zirconium hydride triggering the action,
things like that. That may be put a demand on your for an experimental
database that would be challenging to put together.
MR. HOLAHAN: I understand that, but it seems to me that
there is room in the analysis between top of fuel. Remember, when you
get to top of fuel, you still have one-third of the water left in the
spent fuel pool. Okay. And I think at that point, the fact is you may
see additional signals to the people at the site that there is something
going on, whether it is, you know, additional radiation indications or
whatever, and, you know, I don't think we need to push it all the way to
endpoint being 600 degree clad temperature. But there may be some more
reasonable point. It may be, you know, bottom of the fuel, okay,
uncovery.
DR. POWERS: I think you start going down there, I would
just caution to avoid getting to a point that you have to defend your
study based on your knowledge of chemical kinetics, because I think you
are going to be very, very vulnerable there.
MR. HOLAHAN: We understand that, however, we also recognize
that it puts a conservative basis in the analysis if you don't go
further.
DR. POWERS: It sure does.
MR. HOLAHAN: And you need to in some way acknowledge or
estimate, you know, what that means to the analysis.
DR. KRESS: It seems like your chemical kinetics would
mostly be steam zirc oxidation under that period.
DR. POWERS: I am not persuaded at all that that would be
the case. It mean be steam zirc hydride oxidation.
DR. KRESS: Oh, yeah, I'm sorry. I'm sorry, you are right.
DR. POWERS: And that is what causes your --
DR. KRESS: But it is not air, it is steam at this time.
DR. POWERS: Steam, air, anything, I am not sure I
understand how hydride nodules are going to behave for high burnup
fuels.
DR. KRESS: Should we consider then, in terms of risk
acceptance, this endpoint to be basically equivalent to a LERF?
MS. JACKSON: We are going to -- I have a slide to address
that later on.
MR. HOLAHAN: That is a very significant issue.
MS. JACKSON: And, yeah, it is, that is something we are
looking at, because it is not quite a LERF, but I will get to that in
just a minute, if that is okay.
DR. KRESS: The other question I had was risk is varying
with time.
MS. JACKSON: Yes.
DR. KRESS: And did you pick a time to do this study, like
five years or three years, or did you vary that time?
MS. JACKSON: We varied the time. We looked at short
timeframes of I think like 30 days from shutdown, but the main focus was
on like one year after shutdown. And we had some existing information
that we were able to use from Generic Safety Issue 82 that had
inventories that we could use for fission products and stuff that were
at the pool at one year. So that is where our long-term focus was.
Okay. I wanted to go over a couple of areas that we did
have stakeholder comments in and one of the areas that was a significant
concern was human reliability, as was already picked up.
It was felt that sufficient credit wasn't given to operator
response to adverse plant conditions. In the decommissioning plants
there are no automatically actuating systems like you would see for a
reactor, so there is a heavy reliance on the personnel to identify and
correct any conditions in the spent fuel pool area, and this had an
influence in our PRA.
We took an action item at the workshop to solicit comments
to outside experts in human reliability and to all our stakeholders to
try to identify conditions that would support an assumption of high
human reliability and those conditions were things like plant
procedures, alarms, training that would lead us to say, okay, yes the
operators will identify adverse conditions.
We released our straw man in mid-August. To date right now
we haven't received any technical comments from our stakeholders but we
have gotten back our expert feedback and we are reassessing our
assumptions for human reliability in our assessment and this work is
ongoing, so we don't have any results for you at this time.
For the sake of the committee's time and perhaps the other
speakers, I would like to move to one other area and that would be
criticality.
That is two slides over. Criticality has been raised as a
concern from a member of the public, that we didn't sufficiently address
it in our draft study, so we are going back to look at the potential for
criticality using an expanded scope of scenarios and a ranking or
listing to look at what all has to happen in a sequence to get you to
criticality. That work is currently ongoing now too.
DR. KRESS: Does the fuel have to relocate to go critical or
are there other ways?
MS. JACKSON: Something has to relocate -- either the solid
boral plates or the fuel --
DR. KRESS: Oh, the boral --
MS. JACKSON: You can try and -- even if you had all you
borated water gone --
MR. SIEBER: And put fresh water --
MS. JACKSON: -- and put fresh water in, you would not get a
criticality, so something else has to occur, so we are trying to go
through the whole sequence of what all has to happen to reach a
criticality.
DR. POWERS: To do criticality analyses, what are the
technical capabilities for doing it?
MS. JACKSON: I'm sorry?
DR. POWERS: What are the technical capabilities available
to you for doing criticality analyses?
MS. JACKSON: Can I refer to the Staff? Larry Kopp.
MR. KOPP: Larry Kopp, NRR Staff. We do have some
capabilities inhouse. We have the KENO code that a member of our staff
has used to do some criticality analysis.
Of course, a lot of these are transients and really not
steady state calculations, which are a little more difficult to analyze.
You have got feedback effects which come into play and it's
sort of difficult to analyze a true transient because it is a slow
approach and you don't really know the initiating factors that well.
DR. POWERS: Yes, but basically what you are going to do
with KENO calculations -- fixed hypothesized positions.
MR. KOPP: There are basically two scenarios that we are
looking at. One is a disruption of the fuel and the racks and the play
of any associated poisons and to see whether that could cause some type
of criticality concern. Right now we feel that there probably
doesn't because we can't visualize any way for the UO2 pellets to
conform by themselves into a critical mass without the structure
material and the rest of the poisons.
But the other scenario is something like gradual degradation
of boroflex in the boiling water reactor where the fuel would remain
intact, but there would be no boron in the pool of water to make up for
the increase in reactivity due to the degradation, which is another slow
approach but we are looking at that also.
DR. POWERS: Sure.
DR. SEALE: There's been a fair amount of experimental data
for these kinds of arrays also, and they have been used to benchmark the
KENO, so it is a pretty reliable calculation.
DR. POWERS: I would think it would be doable, but really
the question is trying to add fuel to the concern I have that we are
losing all our capabilities to do adventurous --
DR. SEALE: That's true.
DR. POWERS: -- criticality calculations, and I think we can
end up having problems such as those taking place in Japan.
DR. SEALE: There are some recent experiments that the
French have done at the Maraccas facility on higher burnups, simulated
higher burnup effects and so on, not only for arrays like spent fuel but
also shipping arrays and so on, and that should be useful for
benchmarking in any higher burnup.
DR. POWERS: Yes, that sounds like real useful data.
DR. SEALE: Yes.
MS. JACKSON: Okay. In addition to addressing stakeholders'
concerns, we have other activities in progress now to help finalize our
study. These would include additional technical work we are having
performed to augment our original analyses, and this is mainly in the
area of thermal hydraulics and in PRA.
There is an independent technical review which I mentioned
earlier in progress on our draft report and our independent reviewers
also got all the input from the stakeholders so they could balance their
review on what others think of our draft report.
The independent review are people outside of the Technical
Working Group and they are people from the Office of Research, from
National Labs and from other contractors in specific areas of expertise
We are also in the process of applying the risk informed
principles of Reg Guide 1.174.
This is where I hope to answer your question. For risk
informed decision-making our study is supposed to be risk informed but
not risk based so we want to look at all the principles for Reg Guide
1.174. One of the things we first discovered is that the spent fuel
pool accident frequency and the consequences don't really line up with
the CDF or LERF. Given that we have a release, it doesn't really match
up with the CDF. Given that there is no iodine released from the spent
fuel pool accident, it doesn't quite line up with the LERF.
DR. POWERS: What is your limiting isotope?
MS. JACKSON: It is usually Cesium-137. There's also
another factor that you might have more than one core involved in this,
so you'll have a larger inventory
DR. KRESS: Do you actually have a fission product release
model that you use here or do you use something like MELCOR?
MS. JACKSON: I think we used MACCS. Is that the correct --
DR. POWERS: MACCS is a consequence code.
MS. JACKSON: Okay, I'm sorry then.
DR. APOSTOLAKIS: Do you have a curve frequency
versus release of --
MR. SCHAPEROW: Oh, excuse me. This is Jason Schaperow from
the Office of Research.
We used a release fraction of cesium of one based on some
work that was done back in the early '80s by some Research staff and
also Brookhaven.
DR. KRESS: What did you use for a release fraction for
ruthenium?
MR. SCHAPEROW: My recollection is those release fractions
were small, five percent or less.
DR. POWERS: And you can defend that in light of the
Canadian work?
MR. SCHAPEROW: I am not intimately familiar with the
Canadian work.
DR. POWERS: Well, they have a design basis accident that is
a fuel bundle ejection and so they have been worrying about the release
of ruthenium from fuel exposed to air.
DR. KRESS: It releases a lot faster than you might think.
MR. SCHAPEROW: We can take a look at that. Actually a lot
of these sequences are steam environment. The only one that might be
air would be a seismic maybe where the bottom of the pool would rupture.
You are not going to keep this steam air free.
DR. SEALE: Not when she dries out.
MS. JACKSON: It seems like something we are going to have
to look into.
DR. APOSTOLAKIS: Let me understand the end states again?
What are the end states?
DR. KRESS: Well, right now they mentioned it was top of
fuel, uncovery to top of fuel and the question I had was is this
equivalent to LERF? Well, probably not because LERF was derived from
prompt fatality. Prompt fatality depends on the mix of fission
products, so -- as well as atmospheric dispersion type things, so the
mix of fission products will affect your feeling about what is a LERF
and what isn't and what is an acceptable LERF.
DR. APOSTOLAKIS: Yes, but should it be just a scaler, that
is my question. Shouldn't you have different frequencies for different
kinds of releases -- I mean in a good study?
DR. KRESS: Yes, but you know, to get LERF you add those up.
DR. APOSTOLAKIS: But my point is LERF is not very
meaningful here. I am going to the frequency consequence curves, okay?
DR. KRESS: If you have the right LERF it would be just as
meaningful --
DR. APOSTOLAKIS: I mean it's yes/no right now? We are
either uncovering the fuel or we are not?
MS. JACKSON: Well, you will either have a fire or you won't
have a fire.
DR. POWERS: Yes/no.
DR. APOSTOLAKIS: It is a binary model.
DR. SEALE: The end state though is -- has multiple answers
to it because the end state in terms of whether or not you have a
release accident may well be whether or not you get down to the top of
the core or somewhere near there, but what gets released then depends on
where you go from there. I mean again if you boil off all the water and
so on, you have got an air fire now. That's very different.
DR. WALLIS: What is the end state after an air fire?
MS. JACKSON: After an air fire --
DR. SEALE: Well, a pile of oxide and a highly, a fairly
large unpopulable area I would think.
DR. KRESS: You are driving off the volatile fission
products --
DR. POWERS: More than that, you would be vaporizing fuel.
DR. KRESS: Yes.
DR. SEALE: Yes.
DR. POWERS: You would be manufacturing uranium trioxide
like you wouldn't believe.
DR. APOSTOLAKIS: The question is would it make sense to
have a curve that shows the amount curies released versus the frequency?
DR. KRESS: Of course it would.
DR. APOSTOLAKIS: And right now we are replacing that by a
binary thing that says fuel is uncovered or it is not.
MS. JACKSON: Glenn Kelly?
MR. KELLY: This is Glenn Kelly from the Staff.
When we did the calculation it really is a binary event
because you are either going to have a zirconium fire or you are not.
If you don't have a zirconium fire there is nothing that is energetic
there enough to take the fission produces offsite.
If we have a zirconium fire, we have made an assumption
about how much zirconium is going to burn up.
DR. SEALE: Yes.
MR. KELLY: And given that, you basically burn down the
building and it is released directly to the atmosphere and you are
either doing that or you are not doing that.
Now one may quibble about whether we have got the numbers
exactly right, but clearly what we did come up with was that the results
weren't very good that happened, and so --
DR. KRESS: So you want the frequency of uncovery in the top
of the core to be at an acceptable level?
MR. KELLY: That's correct.
DR. APOSTOLAKIS: So that plays the role of core damage --
DR. WALLIS: Well, how much burns? The fire starts in one
place where it is most likely -- it spreads to the whole thing?
MR. KELLY: We assumed that it was configured in a manner
such that you would be burning up approximately two cores.
MS. JACKSON: So that is your last offload plus like your
last three refueling outages. After that you might not be able to get
propagation to the older fuel and heat it up to the point that it would
get involved in the fire.
MR. SCHAPEROW: Jason Schaperow for Research. Actually it
was three cores.
DR. POWERS: Okay.
MS. JACKSON: Okay.
DR. APOSTOLAKIS: You know, it is important though to have
the supporting documentation because as I look at the numbers I get a
lot of questions, and all it says is go to NUREG such-and-such or go to
INEL such-and-such and find the answer.
For example, probability of recovery of offsite power from
severe weather events and the numbers are different for Case 1 and Case
2. Now Case 2 is simply whether they put spent fuel there a month
before the accident, right?
MS. JACKSON: I believe so.
DR. APOSTOLAKIS: Why does that have anything to do with
recovery from offsite power? It is not clear to me. Does it have
anything to do with it?
MS. JACKSON: Glenn?
MR. KELLY: It has to do with -- well, is Mike here to
answer that one?
MS. JACKSON: Or whomever
MR. HOLAHAN: There is a good reason. We are still looking
it up.
[Laughter.]
MR. HOLAHAN: I mean the big difference -- I can talk about
one of the differences between the two is that with -- at one year you
have significantly longer time available within which you want to get
power back. When you are at one month you are draining down that much
faster and you get in trouble that much more quickly, but I think there
may be something else that Mike was thinking of in that number.
DR. APOSTOLAKIS: Oh, so the time available is different.
MS. JACKSON: Yes.
MR. HOLAHAN: Yes.
DR. SEALE: Very different.
DR. APOSTOLAKIS: And that takes a whole volume to explain?
DR. POWERS: Actually, in the text there is quite a little
discussion of exactly that point.
DR. APOSTOLAKIS: In some places, not everywhere.
DR. POWERS: Not everywhere, I'll admit.
MR. KELLY: Again we apologize for only being able to do
this in two and a half months but if we had had more time, we would have
been happy to --
DR. SEALE: You would have had a shorter document.
MS. JACKSON: To continue on --
DR. APOSTOLAKIS: I have noticed though the eagerness with
which Mike Cheok sat down.
[Laughter.]
DR. APOSTOLAKIS: He couldn't wait.
MR. CHEOK: This is Mike Cheok from the Staff -- from
NUREG-5496 they provide you with a recovery curve and I guess for the
Case 2 you do have a shorter time to recover.
DR. APOSTOLAKIS: Okay, that was the reason.
MS. JACKSON: Okay. In looking at the CDF and the LERF we
are trying to find an analogous criterion that we could use for spent
fuel pool accidents at decommissioning plants. At the same time we are
also looking at balancing defense-in-depth and safety margin and the
ability to monitor performance.
DR. WALLIS: What does defense-in-depth mean in this
context?
MS. JACKSON: That is one of the things we really struggle
with. Obviously in every spent fuel pool you are only down to one of
the three traditional barriers for fission product release. In
decommissioning plants and spent fuel pools you don't have automatic
system actuation and we are looking at reducing emergency preparedness,
which is usually considered a defense-in-depth --
DR. WALLIS: There is no defense-in-depth, at least in the
traditional sense.
MS. JACKSON: Not in the traditional sense, but we are also
looking at balancing that to safety margin, which we believe there is an
increase in safety margin given that you have a longer time to respond
to accidents.
We are not talking minutes or maybe hours. We are talking
hours to days now that you can actually do something to respond, and
that gives you some margin.
DR. WALLIS: As long as there is something to do.
MS. JACKSON: That's true, but in many of the sequences
there is something -- you can call the fire department and bring them
in.
You also have increased safety margin in that your iodine
has decayed away after a few months after shutdown, so you are not going
to have the prompt fatality concerns that you would with an operating
plant, so we are trying to balance these things to say what is an
appropriate --
DR. KRESS: Yes, I think that is maybe an illusion there
because you will have prompt fatalities from the ruthenium and other
things and we are not real sure of what gets released in this kind of
accident.
DR. SEALE: Yes.
MS. JACKSON: We did calculate some but they were a small
amount.
DR. KRESS: Yes, but they were release models that are not
very relevant to the situation.
MS. JACKSON: Okay. That is something we will have to take
into consideration.
DR. WALLIS: Now a fire -- the release is dependent on the
buoyancy of this plume, isn't it? A very hot fire --
DR. KRESS: Oh, it's plenty buoyant, believe me.
DR. WALLIS: Could spread a long way.
MS. JACKSON: Yes.
DR. WALLIS: Of usual magic numbers of miles distant may not
apply anymore.
MS. JACKSON: For EPZ and everything -- yes, the study that
Jason Schaperow did for us on consequences went far beyond the 10 mile
EPZ to look at consequences.
DR. WALLIS: Yes, I think it would --
DR. KRESS: When you use a code like MACCS, you do actually
input an energy function into it and it is factored into the dispersion
model.
DR. WALLIS: Well, what sort of range are we talking about?
Suppose that Maine Yankee has one of these? How far does the plume go?
DR. SHACK: Vermont.
[Laughter.]
DR. WALLIS: It's a Nor'easter.
DR. KRESS: It goes to Dartmouth.
MS. JACKSON: I can tell you in our analyses we looked at I
believe 100 miles and 500 miles away.
DR. WALLIS: So you are talking hundreds of miles.
MS. JACKSON: Yes.
DR. WALLIS: That can get to some pretty populated areas.
MS. JACKSON: It's possible. It's possible, you know --
MR. KELLY: This is Glenn Kelly. When we did the
calculation, we did not do it in 10 miles and in 20 miles and then 40
miles and then 100 miles so that we would know how much of the
population was affected within each one of those circles. We do have
numbers for 100 miles and for 500 miles but to say what did that -- most
of the dose was happening close in or far out I think would take a
little bit more work on our part.
DR. WALLIS: You pray for rain or something.
MS. JACKSON: Yes.
MR. KELLY: As long as you are not under the rain.
DR. KRESS: That's right. Actually an energetic release is
probably kind of good for you because it puts it up high and disperses
it --
DR. WALLIS: Sends it to somebody else.
DR. KRESS: It gives a lot of cancers but it doesn't give as
many prompt fatalities.
DR. APOSTOLAKIS: Is the quality of your risk assessment
subject to the same criticism of incompleteness of the reactor risk
assessments, do you think?
MS. JACKSON: I see Glenn shaking his head yes.
DR. APOSTOLAKIS: So what is it that you are leaving out?
MR. KELLY: Well, I mean one can always postulate something
else and from that same standpoint we can always postulate something --
I mean we certainly didn't look at meteorites and there were a lot of
other things that were not part of our evaluation, but we did look at a
broader spectrum of initiating events than had been looked at in any
previous study.
And we looked at them in we believe a sufficiently wide
manner that were we looking at loss of inventory, loss of cooling, and
then rapid catastrophic events, --
DR. APOSTOLAKIS: Let me put in a different way then.
MR. KELLY: Sure.
DR. APOSTOLAKIS: You are familiar with the active PRAs,
right?
MR. KELLY: Yes, I am.
DR. APOSTOLAKIS: Would you tend to rely more on the results
of your risk assessment here than you would rely on reactor risk
assessments to make decisions? Are you more confident that here your
numbers are more representative of what can go wrong?
MR. KELLY: In this particular case, I would say that when
we did this risk assessment, the basis of performing this initial risk
assessment was to identify areas that we felt required additional effort
on the staff's part to assure that they wouldn't be problem areas. We
were not doing this on a basis of trying to find the right number, so to
speak, the exact number.
DR. APOSTOLAKIS: Yeah, I am not really referring to this
particular document which would perhaps you did under severe time
constraints, but if you had the time to finish this.
MR. KELLY: Well, again, this is a very generic one because
it was not built to a particular design.
DR. APOSTOLAKIS: Well, let me make the question different
then.
MR. KELLY: Okay.
DR. APOSTOLAKIS: Is this a case where I really don't need
to go to all the principles of Regulatory Guide 1.174, I don't have to
worry about defense-in-depth because I am fairly confident that my risk
numbers and my PRA is giving me a sufficient information basis for
making decisions. The reason why we have these principles in 1.174 is
that we don't really trust the results of the PRA, that we know their
holes, we know this, we know that.
Now, in this particular case, though, do I have to take all
these principles and take them here and worry about defense-in-depth and
safety margins and so on, or can it come closer to risk-based than
risk-informed in this case?
DR. KRESS: It depends on the uncertainty in your final
answer.
DR. APOSTOLAKIS: I know.
DR. KRESS: And I would guess that the uncertainty in this
type of risk analysis ought to be far less than the one in the full
power reactor, because it is a simpler system, much less can go wrong.
DR. APOSTOLAKIS: Exactly.
DR. KRESS: You ought to be able to say the uncertainty in
this calculation, if you did it, is such that you ought not have to go
to these 1.174 --
DR. APOSTOLAKIS: Right. That is what I am driving at. Is
this --
DR. KRESS: But you ought to have that uncertainty done.
DR. APOSTOLAKIS: Sure.
DR. KRESS: And you ought to have some confidence level in
your result.
DR. APOSTOLAKIS: And that is why I said that, you know,
they should be given the time to complete this analysis.
DR. SEALE: On the other hand, the great difference between
the consequences of the two -- the binary nature of this accident is
such that if you can find a magic silver bullet that will always assure
you that you do not go to the fire case, as some kind of
defense-in-depth, that would be a very attractive thing to have.
DR. APOSTOLAKIS: But the issue here is not whether I want
to implement defense-in-depth. The issue here is, is defense-in-depth a
principle or is it something that, for the measures that are equivalent
to defense-in-depth, will flow naturally from my risk assessment? I may
very well do this, Bob, but I may conclude that from the risk
assessment, without involving a principle that can -- that will impose
something on me independently of the risk numbers.
DR. SEALE: Clearly, the analysis will show that the first
-- the lesser consequence is by far the more attractive.
DR. APOSTOLAKIS: Yes, I agree with Tom. It seems to me
this is a good candidate for going the rationalist way.
DR. KRESS: A good candidate.
DR. SEALE: I think it is fine after someone else has done
it.
DR. APOSTOLAKIS: Commissioner McGaffigan may know about it,
by the way.
DR. SEALE: And maybe you have done two or three, but I
think you always have the completeness concern until you have gone at it
a couple of times.
DR. APOSTOLAKIS: Right. And I understand that, that is why
I asked the question. But is the completeness issue here of a similar
magnitude as in -- and I don't think so. I don't think so.
DR. KRESS: Rich is going to speak to that.
MR. BARRETT: This is Richard Barrett with the NRR staff. I
think I can agree with a lot of what has been said here in that to go
into the five principles at the same level of detail that we might do
for a full reactor PRA might not be justified. On the other hand, when
we look at the risk analysis, we see a wide spectrum of sequences. Some
of these sequences require -- involve many, many days to evolve. They
involve the failure of equipment, the failure of support equipment, the
failure of operator actions. And you can look at these calculations and
have some confidence.
On the other hand, there are some scenarios in which a
seismic event can occur and there is no opportunity in the model for
recovery actions, or not with any high degree of confidence. So we
believe that at least a look at the other principles, to examine, as
Diane so aptly put it, the tradeoffs between the inherent margin that is
built into this situation, and the defense-in-depth questions. But keep
in mind, as a background, that the defense-in-depth that we are talking
about here relates as well, we have operating reactors today with spent
fuel pools. We have already made decisions about the tradeoff between
margin and defense-in-depth, so we are not talking about a radical
departure from that, obviously.
DR. POWERS: I think I am going to have to plead for us to
move on on this subject.
DR. KRESS: Yeah, I think we are running short on time. We
probably are going to have to move on.
MS. JACKSON: Okay. I am just going to finish up. Based on
all of our inputs, including the risk assessment, our stakeholder
inputs, our industry commitments, our deterministic analyses, and
applying our risk-informed principles, we think we can develop a
realistic, risk-informed assessment that will provide technical bases
for the development of rulemaking and for the development of interim
exemption criteria
We think one of the keys to having a realistic assessment is
industry commitments that we would be able to credit in our analyses.
Our schedule for the remainder of the project is to release the draft
for comment report in early January, have a public comment period and be
able to release our final report at the beginning of April.
DR. APOSTOLAKIS: When are we going to see you again at the
ACRS?
MS. JACKSON: At your leisure. When would you like to see
us again?
MR. HOLAHAN: You haven't asked.
DR. POWERS: We have but to ask.
DR. KRESS: We will talk about it
DR. APOSTOLAKIS: We will talk about it.
MS. JACKSON: Whenever you would like, we will come.
DR. APOSTOLAKIS: What can I say?
MS. JACKSON: I would like to thank you all for you time
this morning.
DR. APOSTOLAKIS: I must note, Mr. Chairman, that this
confirms something that I always suspected, that we don't all mean the
same thing by defense-in-depth.
DR. KRESS: That's right.
DR. APOSTOLAKIS: And this is an issue that has to be
resolved.
DR. KRESS: Good comment. At this time we are scheduled to
move on.
DR. APOSTOLAKIS: And I would also like to know how many
hands Rich Barrett has. He used the expression "on the other hand"
several times.
[Laughter.]
DR. KRESS: Let's move on. We are now scheduled to hear
from the Nuclear Energy Institute, Alan Nelson I think is going to talk
to us. No, I have got that wrong. Somebody is going to talk to us.
The Nuclear Energy Institute has reviewed this draft
document and they have some positions and comments to make on it I
think, so let's --
MS. HENDRICKS: Good morning. I'm Lynnette. I'm the
director of -- Lynnette Hendricks, the director of plant support at NEI.
My group has, among many other support-type issues, like radiation
protection and emergency preparedness. We have decommissioning and dry
storage and low-level waste. So that's sort of where we come from.
I just wanted to make a few introductory remarks, and I'm
going to turn over the discussion of the extensive work industry has put
into this issue and the risk study, and I hope you've all been provided
a copy of the Erin report we had -- Erin Engineering, who was doing a
lot of the IPEs, prepare an analysis of the staff's report.
Just a couple of introductory remarks. Decommissioning is
very important to the industry. We think it has -- if we're unable to
proceed through it in a timely, efficient, safe manner, it has a lot of
implications. Ironically, after the discussion today, decommissioning
is generally referred to as relatively a low-risk endeavor, but I think
we need to remember that it has the inability to proceed through it
efficiently in a cost effective manner. It has impacts on the public
and our rate payers and shareholders. The reason for that is if you get
into decommissioning and lot of these major questions aren't answered, I
don't think it gives the public a good impression if we can't proceed
through effectively and efficiently and could also give them the
impression that it's -- it's -- poses a lot more risks than maybe it
really does.
DR. KRESS: Would, say a time frame of difference between
three years and five years make much difference to you in terms of cost
and burden and--
MS. HENDRICKS: It would make a considerable difference.
What we -- the staff mentioned that this was a basis to look at certain
regulations applicable to decommissioning that are susceptible to
risk-informing; many others aren't. Those would be EP, financial
protection -- I think we've estimated at one point that the cost is
about $5 million a year, a couple million in insurance requirements if
you can't determine that you are out of a range where you can have the
equivalent of large early release and the type of things that financial
protection is intended for. Likewise, if you're required to keep a
large staff of emergency preparedness to -- and that one's a little
questionable, because of the latent effects, you don't have a large
early release, so what is the reason for your off-site emergency
preparedness plan. But, yes, it would -- it does have a significant
effect if you assume three years versus five years.
I also as an introductory remark -- we're briefing the
Commission, along with the staff, on Monday, as you probably know in
decommissioning issues, and I just wanted to not get into our other
issues at this point, because I think you're very appropriately focused
on the risk study; but wanted to, as a place holder perhaps for further
discussions with you, there are two other components to the
decommissioning process that affect us very much. You risk inform the
process initially, and then get out of requirements that are no longer
applicable. You need to offload your spent fuel into dry casks. That
is an issue that we've been very concerned, working with the staff, and
also an issue that I think could very much benefit from a risk-informed
approach.
And the third issue is when you actually get into the
license termination plan -- what should you be providing at what phase,
and there's some important issues there. But I don't want to digress
into any of those, and at this point, I'd like to turn it over to Mike
Meisner, who's, in addition to being president of Maine Yankee, is also
the chairman of our decommissioning working group.
MR. MEISNER: Good morning. Can you hear me? Is this on?
Pardon me?
DR. POWERS: There's a switch.
MR. MEISNER: Okay, how's that?
DR. POWERS: Better.
MR. MEISNER: Okay, you've heard a lot of the background
from the staff this morning, so I'm going to be kind of selective in
what I talk about. We've spent a lot of time looking at the staff's
model. We think, in fact, that it's a -- it's a very good model from
the point of view event trees, fault trees--that kind of stuff. The
problem that we've had with what the staff has issued is the inputs to
those models. And we think in virtually every case that the -- they've
developed an extremely conservative PRA model here that generally goes
to the worst case. You indicated very high numbers, for instance, for
human error probabilities. That's the case. And as a result, we think
that the information that you can derive from that model, from that
conservative model is very skewed and doesn't give us much insight to
operate our facilities by.
DR. WALLIS: What sort of factor -- is the contention about?
Is it a factor of ten or something in the estimated probabilities or
what?
MR. MEISNER: We think they're high by several orders of
magnitude.
DR. WALLIS: Orders of magnitude?
MR. MEISNER: I hope you all --
DR. WALLIS: Well, what do you appeal to in order to resolve
this? I mean in the case of physical phenomena, you do an experiment.
How do you -- what do you appeal to resolve in the factors -- in orders
of magnitude?
MR. MEISNER: Well, let me give you few examples, okay, and
then -- I hope you all have a copy of this report, and if you haven't
gone through it--
DR. KRESS: We have it.
MR. MEISNER: Please do. It's a pretty detailed review of
the staff's study and the areas of concern that we have. And I need to
emphasize too that the -- what I'm going to be talking about today and
on Monday with the Commission is based on that draft report the staff
issued. And we've had a workshop with them and lot of discussions, but
it's been four months since the workshop and we still have no additional
information as to how the model's been changed. So I'm just going to be
falling back on what the staff has already issued, in my discussions.
Let's talk about some examples where we think the model is
particularly conservative. Human reliability is the key area. Human
error dominates the results in the staff's study. And to get at the
issue, let me paint you a bit of picture, okay, and I'll use Maine
Yankee as an example.
If you came up to Maine Yankee today, what you'd see is a
new control room. And the control room is about a quarter of the size
of this room. It's got a couple of indications in it--things like
temperature and level. No other panels. We have two operators all the
time. And all those two operators do is look at a couple of instruments
and go out and walk through the spent fuel pool, doing their rounds.
All they have to look at is the spent fuel pool. Now, in
that context what the staff is saying is that for the long-lasting --
long-acting events, these -- all events associated with the spent fuel
pool that aren't instantaneous, like your catastrophic drain-down due to
seismic -- all other events are -- take on the order of five to eight
days to develop. So what the staff is saying in their model is that the
operators on shift are going to fail to get water into the spent fuel
pool, and then the next shift is going to fail, and the next shift, and
the next shift going on five to eight days. And they've assigned a
single failure probability to that likelihood such that -- and I -- it's
generally on the order of ten to the minus fourth that is well in excess
of anything, even IPEs used for similar kinds of events. And, as a
result, the numbers that you see in the PRA analysis challenge IPEs--the
core damage frequency numbers. It's very unrealistic to expect that
shift after shift after shift someone is going to fail to do a very
simple action, and that's get water into the pool.
DR. POWERS: You make that point in your review document at
-- how many shifts does this time period represent. But we've had other
people make the point that things have happened in fuel pools that have
gone on for days without people knowing -- acting on it or recognizing
it. So, I mean, it's not beyond the pale, which you could have a large
number of shifts with nobody catching something. And I think Brown
might argue--
B: Browns Ferry went for three days, and the temperature
went up and nobody knew it--recognized it.
DR. POWERS: Yes, we had these anecdotal accounts. In fact,
it may well be the efforts go on for a few shifts, then it's almost
guaranteed to keep going on for more shifts.
MR. MEISNER: Okay, well, let me address that.
DR. POWERS: (**Inaudible**) looking like it's normal.
MR. MEISNER: Yes, and what happened at Browns Ferry was the
temperature went up 20 degrees or so, if I remember right. As an
operating plant, let's fall back on simplicity. Those operators were
running their facility, and weren't focused solely on the spent fuel
pool. As the temperature went up, they eventually caught it, which I
think proves the point within what a couple days, if I remember right.
MR. BARTON: Three.
MR. MEISNER: Three days. And that temperature hadn't even
gotten up to the point of challenging tech spec limits, much less
boiling and steaming. What happens in these pools is most events are
self-revealing. If we start steaming in our pool and most pools, you're
eventually going to get kind of a rain forest atmosphere in there. It's
impossible to miss -- well before any kind of an event could progress to
the point where you'd have a concern, it's going to reveal itself. What
do we have to do in all cases? Only one thing, and that's get water
into the pools. We have multiple means to do that. Worst case, you
know, with days and days to recover, we can set up a bucket brigade out
to the bay to get water into the pool. The idea that somehow we're
going to fail to do that one action, which is the only recovery action
that the operators have, know, and are trained on and work to procedures
on is just incredible to the industry. And when you -- when you assume
those kinds of high probabilities for failure, I think you do a
disservice to the purpose of the PRA. We want to get some risk insights
out of this that will be useful for us in going forward.
DR. APOSTOLAKIS: It seems to me that part of the problem is
the use of point values, and at some point that we should really see an
uncertainty analysis, because I think it's easier to defend a curve and
a point value. And then, of course, you may argue that the curve has
shifted towards higher values, but I think a lot of the argument will go
away, but certainly the human reliability part I'm very much interested
in, and I would like to understand a little better. Maybe sending me --
by sending me the supporting documents, and I'd like to look at that.
DR. KRESS: Yes -- my question was going to be along those
same lines, George, and I was going to also ask what is the basis for
choosing any number. Don't you have to have some human factor studies
that says under these circumstances, the chances are from here to
here--in this range. I mean, I don't know -- I don't even know if that
exists.
DR. APOSTOLAKIS: The issue of several shifts -- I mean is
-- you immediately ask questions like, you know, is the reason why they
don't catch it something that is common to all the shifts? Or is it
just that they don't pay attention? I mean, different probabilities for
these things. By the way--
MR. MEISNER: On the other hand--
DR. POWERS: The speaker is correct that before you can get
into trouble here, something has to be so bad that you -- it would be
impossible to miss. I mean, you would have to -- the operators would
have to be held away from this facility with -- by men with guns.
DR. APOSTOLAKIS: Yes.
DR. KRESS: Does that mean that human error is ten to the
minus five or ten to the minus six? What number is put on it?
DR. APOSTOLAKIS: There are conditional errors in the event
trees that are one, and I'd like to know why. I just saw one.
DR. KRESS: You just saw one as one.
DR. APOSTOLAKIS: One. And yet that tree has another
branch, too. You might say this is a computer code, but it's one.
MR. MEISNER: Let me give a point of comparison.
DR. APOSTOLAKIS: It's fairly high.
MR. MEISNER: IPEs.
DR. APOSTOLAKIS: Yes.
MR. MEISNER: The general approach is IPEs is when an event
continues, say, beyond 24 hours or 48 hours, you truncate that sequence
on the assumption that there's more than sufficient time to recover.
DR. APOSTOLAKIS: Yes.
MR. MEISNER: Let me ask you all, who are probably better at
PRAs than I am, what the effect might be on IPEs if you took every
truncated sequence out and never allowed, and always assigned a failure
probability to that sequence. My guess is that you'd probably increase
core damage frequencies across the board in order of magnitude.
DR. APOSTOLAKIS: Yes, and, you know--
MR. MEISNER: And our concern here is that the staff is
departing from a consistent approach with IPEs or shutdown PRAs; that
they're not taking a realistic view of decommissioning and folding that
into a PRA. And fundamental to PRAs is the idea that you take a
realistic approach. You don't take an excessively conservative one,
else you're going to mask what the real contributors are to risk
DR. APOSTOLAKIS: Yes, I must say I looked at some of the
numbers, and it says the operators have 132 hours to do these -- the
probability they will not do it is 0.2. I would like to know the
rationale behind that, or .02. I mean that's a pretty high number when
you have a hundred and thirty-two hours.
DR. SEALE: Yes.
DR. APOSTOLAKIS: On the other hand, you know, I would knot
invoke consistency with IPEs too much. I would just argue in terms of
logic.
DR. SEALE: Yes.
DR. APOSTOLAKIS: Because the IPEs are not enjoying --
nothing. I will not complete the sentence.
[Laughter.]
DR. WALLIS: George? George?
MR. MEISNER: Let me give you another example that you --
excuse me.
DR. WALLIS: Okay, you make your example, and then I want to
ask George something. Go ahead.
MR. MEISNER: Go ahead. Who? You talked earlier this
morning about zirc ignition temperatures. Staff's using 800 degrees.
If you look at the Erin report that we gave you, it provides some
practical situations that demonstrate that that temperature isn't even
close to what we should be using in our analysis.
DR. KRESS: Don't you lose a lot of credibility when you say
that? Because you can look at the technical basis behind these curves
they handed out, and it is 800 degrees.
MR. MEISNER: Okay, well, let me give you an example. When
they make these tubes -- when they roll the tubes and forge them, it's
at a temperature of 1,100 degrees Centigrade in the manufacturing
process.
DR. KRESS: The trouble is ignition temperature is a
function of geometries, heat transfer coefficients, reaction rates.
It's not a fixed thing. It's a geometry-dependent thing, and this thing
took those into consideration--the geometry. And it is -- I mean, you
can look at this, and I believe it is 800 degrees. That's a good number
to use, and to really use that as a argument against what they're doing
is I think a disservice, frankly. Well, wouldn't you expect that if you
were going to manufacture these things at a temperature much higher than
800 degrees that you would have seen some kind of runaway oxidation
reaction?
MS. HENDRICKS: We had some concerns in going through this
and preparing our comments originally about the bases for -- behind that
study that the fuel is sort of taken out and heated up. I wish I
remember the particulars, but EPRI's (**check word**) been very involved
in this, and if it would be of interest, we'll get back to you
specifically on that comment.
MR. MEISNER: And consider, too, we're taking these fuel
bundles out of the pools, and we're putting them in dry casks. We --
you know, as early as two years after shut down.
DR. KRESS: But maybe we ought to go back and look at that.
DR. WALLIS: The question I had for George. Is here still
here, or has he gone away?
DR. KRESS: George is--
MR. HUFFMAN: I believe that the practice is five years.
The regulations may allow you to do that earlier, but the tech specs for
the certified casks that exist now -- this is Bill Huffman, by the way,
in projects -- is five years or longer.
MR. MEISNER: Yes, that's right. But we were just talking
yesterday about with EPRI, we were unloading some casks that have been
loaded for 14 years, and the bundles were put in those casks two years
after shutdown. There's a lot of real information out there that really
should be taken into consideration is my main point.
MS. HENDRICKS: And those bundles were set throughout the
14-year-old year period. No leakage was determined, and they have no
indication that there's been a lot of oxidation. There's not a lot of
finds or -- I think NRC's participating with EPRI on that, so that's
information that's -- would be directly available from NRC's
participation.
DR. POWERS: Have you looked at fuel with hydriding deposits
on them?
MR. MEISNER: If we have, I'm not aware of it.
DR. POWERS: What do you suspect zirconium hydrides do when
they're exposed to air? I know what uranium hydrides do. I don't have
any idea what zirconium hydrides do.
MR. MEISNER: I couldn't answer your question. What I'm
trying to say, though, is as a practical matter, I assume those hydrides
exist in fuel that's sitting in casks. And, we've seen no adverse
effects -- anything approaching a zirc oxidation reaction.
DR. POWERS: I suspect the hydrides you've got in existing
fuels are distributed, and you don't have hydride nodules the way you
will in fuel that's gone to burn ups and excess of 40 gigawatt days per
ton.
MR. MEISNER: Good.
DR. POWERS: I mean, that's typically the precipitation
levels.
DR. WALLIS: I had a question for George. George, you were
telling us earlier that this is a simpler problem; therefore, one ought
to be able to rely on the PRA and might not need to--
DR. APOSTOLAKIS: I was asking.
DR. WALLIS: All the extra miles. And yet, now, we're
hearing that this disagreements at the very sort of basic level of
orders of magnitude in the probabilities. So how can you rely on
something like that?
DR. APOSTOLAKIS: I was not saying that this is a simpler
problem in the sense that the calculations will not be debatable. I
think the fundamental reason why we went to risk-informed regulation is
the issue of completeness. And I'm not sure that the issue of
completeness here is as important as it is for reactors. Now, the fact
that you will have large uncertainties will guide you to apply perhaps
redundancy, diversity, and the usual defense and depth measures, but my
point was that you didn't have to invoke any principles for that. But I
-- I'm not surprised that the numbers, you know, are debatable.
DR. WALLIS: They're debatable by apparently large factors.
DR. APOSTOLAKIS: It's a very different -- yes, but it's a
different philosophical approach to regulation.
DR. POWERS: Again, I think we're going to have to move
along here.
DR. KRESS: Yes, we're running out of time.
MR. MEISNER: A comment on the end point. When you look at
fuel uncovery, you do, in fact, mask the notion that there's a good deal
more time for operators to do something in those kinds of situations.
And if you look at realistic heat up times and the end point being the
actual oxidation reaction itself rather than the five days that the
staff is using for recovery times, you have something approaching more
like eight. And most of that time is valuable, available time without
high radiation levels that we can use to get water back into the pool.
The industry has made a number of commitments to the staff
as a result of their analysis so that they could have additional comfort
in changing many of the assumptions in the study--things like having
procedures to get water into the pool, training, some hardware changes,
such as ensuring that you have self-limiting seals, if you use seals in
your -- around your pool. And we're waiting expectantly to see what
credit that -- those commitments are going to give us in the staff's
analysis.
We do think their study has to be revised significantly to
use best estimates, as PRAs should, to remove conservatisms, because
conservatisms are inappropriate in PRAs. And the most important thing
we think is they need to be consistent with how PRAs have been done up
to this point in things like truncating sequences beyond two days. And
with all that done, a requantification of the model we think is going to
show that the type of risk associated with zirconium fire is very low.
DR. WALLIS: What sort of numbers does your model show the
risk to be?
MR. MEISNER: Down to ten to the minus seventh to ten to the
minus eighth range, which, by the way, all previous NRC studies have
shown as well. So, with a corrected study, we think we're going to
actually get some useful risk insights so that we can apply our
resources to the right areas in managing these spent fuel pools. And we
think, too, that that will then give the staff the basis to really
risk-inform the regulations, provide a better transition period in the
regulations for newly decommissioned plants. And we do have a concern,
although you caution not to talk about it. But we do have a concern
that with the staff proceeding as they are that the kinds of
assumptions, approaches, and methodologies they use in this study will
tend to undermine a lot of the work that's already been done in
operating plants, both in IPEs and in shutdown PRAs. And the -- we're
concerned that rather than risk-informing the process, we'll be taking a
step backwards and setting a new standard for conservative PRAs versus
realistic PRAs.
So, can I answer any questions?
MS. HENDRICKS: I'd like to actually add something. I'm
wishing we would have brought some sort of a diagram to show what
portion -- where the risk comes out on this. Basically, if you look at
it in those terms, seismic is and was about ten to the minus six, one
times ten to the minus six. We've recalculated that, as has NRC based
on some Livermore results, and it's gone down I think by a factor of
two--something like that. The remaining risk and I'm sure the staff
will correct me if I'm oversimplifying off the top of my head, but a
large part of the remaining risk where you could get a catastrophic pool
rupture comes from heavy loads. Heavy loads was dispositioned in New
Reg 1353 as not being a concern for operating plant spent fuel pools at
ten to the minus eighth. The requantification that the staff has done
brings that back down also to ten to the minus six. And the remainder
of the risks that -- in all fairness, it may have since been
recalculated -- but the remainder of the risks that brings the overall
risk up to ten to the minus five, which obviously is about an order of
magnitude from the seismic plus the heavy load's ten to the minus six
comes from these very long-term sequences, primarily where you have
several days. The point I'd like to make is we've stated previously
that this is human error driven, but I think if you put it in little --
you apportion it according to the total risk, you see just how much of
it is human error driven.
And so -- I think it becomes almost a policy issue for the
commission to say whether they will model these with current
requirements taken care of and with credit for some of the commitments
made going forward, with some assumptions that there will be a
regulatory program in place that will affect what kind of numbers you
end up assigning to these human reliability portions of the sequence.
Currently, they've taken a simplistic approach and just
said, the whole sequence is ten to the minus four, which isn't too bad,
except you add up a bunch of ten to the minus fours, and you get a --
you know -- you get a big number.
Another approach would have been to have gone through the
sequence and given different human liability credit at different stages.
For example, you have the stage where you've got a leak, and you haven't
noticed--maybe comparable to the Browns Ferry situation. Okay, now,
it's gone down further, and you've got a rain forest. And then, again,
you're still ignoring it. And you've gone down some more, and you get
radiation alarms going off. I mean, you can kind of see how perhaps a
more sophisticated approach to the human reliability analysis would just
make a completely different outcome in terms of the bottom line.
And I'd like to emphasize I guess in closing that NEI was
very concerned when this result came out, as indicating to the public in
a (**inaudible**) that went to the Commission, although the results were
preliminary -- what the public was told was that this decommissioning
phase with fuel in the pool poses a greater risk in many cases than the
operating plant itself. That's somewhat illogical, and I think it's
probably -- wasn't a good practice to come up -- to put that before the
Commission prior to finalizing the study with a little more peer review
and a little more certainty on what that number really is more likely to
be when it's refined.
DR. KRESS: Okay, with that we're now scheduled to hear from
some members of the public. Did you want to--
MR. HUFFMAN: Bill Huffman, again, for projects. I'd like
to just make a minor correction. The Commission probably was privy of
the draft report where there might be implications that the risk could
be comparable to operating reactors or much greater than previously
suspected, but the SECY that posed the staff do this study never said
that the risks were greater. We just characterized that they were
different from what we had previously expected. So, the Commission was
never told nor the public in formal SECY that the risks were greater.
MS. HENDRICKS: I believe the number was in the SECY, but
Id' have to go back and check.
DR. KRESS: Okay. So I guess we'll hear from members of the
public now. I think the next on the agenda is Mr. Pete Atherton, a
member of the public, wishes to make some comments.
Come up front, please. We are running a little behind, so
try to stick to the time limits if possible.
MR. ATHERTON: May name is Peter James Atherton.
DR. POWERS: Agree to wire yourself up.
DR. KRESS: Yes, we need to get the mike on you so that we
can get you on the--
Hook it up close to the -- that's right. Very good.
MR. ATHERTON: My name is Peter James Atherton. I was -- is
my voice audible? I serve -- recently, I've been serving as nuclear
safety consult to members of the public. I've been representing their
interests at nuclear power plants, primarily at public hearings. I have
nuclear and electrical engineering degrees. I used to work for the
Nuclear Regulatory Commission in the '70s. I am personally interested
in what I started in 1978 concerning Safety Evaluation Report on the
Power Protection Systems of the Maine Yankee Nuclear Plant, and I'm
interested in continuing to follow that, which has thrust me into the
decommissioning arena.
Surprisingly, you know, many of the subject matters that I
wanted to talk about, you all have addressed in one way or another. And
I would like to not repeat these unnecessarily, but to pose a question--
DR. APOSTOLAKIS: Did you say, surprisingly?
MR. ATHERTON: Well, I did not know that your concerns would
have been -- would have paralleled some of the questions that I have
addressing during the course of the -- of my participation with the
hearings and the -- and my involvement with the working groups over the
last six or eight months. So I too -- I was surprised. This is my
first involvement with the ACRS. Again, so I'm not familiar with how
you conduct your business, and so I've been listening attentively.
Getting to the PRA matter, I'd like to project an attitude,
rather than get into technical details. And I'd like to say that my
person interest is with Maine Yankee, but I'm representing the interests
in the way that I'm able to interpret them from people in and around
nuclear power plants from the Great Lakes region through the New England
area primarily. And one of the concerns with some of these people is
the risk assessment techniques that NRC is using. There is a concern
that the risk assessment technique does not go to the benefits and the
costs. They have an attitude -- I'm just going to basically summarize
these -- they have an attitude that they would like to project that, and
I'm quoting, "no risk is acceptable if it is avoidable."
And to the extent -- I'd like to move into the spent fuel
pool arena and make some general comments. The spent fuel pool in PWRs
is outside containment. There is no containment structure for this. If
there's a catastrophe there, you can bet it's going to endanger the
public. The conservative margin, which I tend to agree with NRC on,
should be enhanced because of the lack of defense in depth for spent
fuel pools, as Ms. Jackson has addressed. And I would urge that you all
err on the side of caution whenever there's a question with regard to
conservatism or liberalism in the interpretation of criteria.
There is one other general concern. Many plants have been
going through decommissioning within the last few years recently, and
the -- there are people, especially people in the New England area and
the Great Lakes area who are interested in what's happening. I would
ask from a general overall approach without getting into the regulations
that once a plant has decided to permanently shutdown that it's going to
go through a decommissioning process. There are members of the public
who would like to know -- who live in and around these plants -- who
would like to know what's happening. Before the plant is dismantled,
they would like to have some sort of input to provide comments, find out
what's going on at the plant, and generally be permitted access to
whatever is taking place rather than the current tendency which, at
least in one instance at Yankee Row -- I mention that specifically --
there appears to be some antagonism, and some efforts to not involve the
public in participation with what's happening at a plant that they live
around. So that would be the second issue that I would like to address.
We do not talk about seismic concerns at all. Mr. Meisner
has addressed issues concerning the drainage of the spent fuel pool and
what would happen thereafter and the ability to refill it. There is
some spent fuel pools -- different spent fuel pools are designed
differently. Most of them have inner liners. Most of them have
stainless steel inner liners. Some of them may not have a liner. Some
of the older ones may have a fiberglass liner. Some of the older ones
leak, and so we already have leakage. The use, without getting to
specifics, we have had plants in operation since the mid-'50s, with
spent fuel pools in operation since then. I have not seen in any
calculations conservatism taken into account for the degradation of the
liner or the spent -- or the concrete structure of the spent fuel pool
as a result of its aging and sitting and encountering the various
environmental factors that it has encountered over time. I haven't seen
a corrective margin for that, or I have not seen it addressed. I have
seen people in a deterministic and very broad perspective try to avoid
the issue. And I would like to urge NRC to address that. I understand
they've hired a consultant for that specific issue.
I raise criticality concerns--going on to the next
topic--with the NRC. The information that I've been provided in my off
the record communications with them goes back to the '50s and '60s
concerning testing and analyses that were done in that matter. I don't
know what the fuel enrichment was back then. I don't know what type of
cladding was used, whether it was stainless steel, whether it's
zirconium, whether it was some other testing material that they were
using. I don't know what, if anything, the criteria that was done some
thirty, forty years ago, how that would apply today if they were going
to use that. And I heard Mr. Kopp's presentation indicating he was
looking into the criticality issues some more, and I have an obligation
to consult with him separately, off the record, on this matter.
In one other instance, we have an inclination, at least
experimentally, to go to mixed oxide fuel for fuel cladding -- I mean,
for fuel. I haven't seen how that added enrichment is going to be taken
into account in spent fuel pools.
DR. POWERS: Well, I think that the move toward mixed oxide
fuel has to be considered somewhat speculative right now, and it would
be for a particular customer, the Department of Energy. So I think -- I
think we don't want to make that generalization. It will be for
specific plants at best. And it's a long ways down the pike here.
MR. ATHERTON: Okay, also the variation in the enrichment of
the fuel - U-235 that is being used today.
We didn't talk much about terrorism, and I understand that's
a topic that people do not wish to talk about on the record. However, I
will address the fact that we don't have a containment around spent fuel
pools, and if there was an attempt to do some damage maliciously, we
could have a problem, and we're not looking into those consequences from
that point of view that I'm aware of. I just wanted to raise that
issue.
And, of course, as an electrical engineer, I have concerns
about equipment qualification and single failure criteria for equipment
that is actually being used to cool a spent fuel pool. It was never
designed to meet the single failure criteria, or it was never designed
to meet the Class 1E electrical requirements--basic, general safety
grade requirements.
If we're going to have a spent fuel pool that is going to be
used over a period of time to store fuel, in some cases over a period of
time beyond its originally designed capability to store fuel, I would
like to suggest that equipment qualification could become an issue from
one perspective. How are we going to know how reliable -- how are we
going to get probability numbers for failure rates for this equipment if
we don't have a known grade of equipment that we can develop these
numbers for?
Ms. Jackson's already mentioned that we don't have an
automatic protection system for the spent fuel pool area. From the
safety perspective, we're relying upon operator performance. I would
suggest to you, and as I understand it, Mr. Meisner has proposed at
least at one of the meetings, that some specific parts of the spent fuel
pool electrical systems are going to meet the Class 1E safety grade
requirements. The specifics of that I do not know. But that was an
industry proposal, which they should be commended for, in my opinion.
And I think I've used up my time, but let me just add one
last point. This goes to the probabilities issue. Back in 1975,
Stephen H. Hanauer was the technical advisor to the NRC. He also served
as a member of the ACRS during the late '60s and early '70s. As a
technical advisor, he received a draft of ANSI N-182, which was then
dated November 2nd, 1974. He wrote a very brief memo, and he was
notorious for doing this, to Guy Arlotta, who was assistant director for
safety and materials protection and standards. Now, let me just read
this for the record. It's two paragraphs.
The first paragraph reads: "It is my understanding that
this is to be rewritten." This is an ANSI draft standard. "In view of
the Browns Ferry fire," which had occurred in March of 1975, and this
memo was written May 6th, 1975, "and lessons forthcoming therefrom, I
wonder whether it should be kept on ice for a while.
"The idea" -- second paragraph -- "the idea of a
probabilistic evaluation that purports to show that the separation is
not required leaves me absolutely cold. You can make probabilistic
numbers prove anything, by which I mean that probabilistic numbers prove
nothing. If this project is not to be put on ice pending the Browns
Ferry fire lessons, I would like to comment further."
This was the attitude of some of our hierarchy at the NRC
and the former AEC at the time concerning the use of probabilities. I
-- it would appear to me that in view of this and my own personal
knowledge of the skepticism that the use of probabilities was considered
to be part of by members of the staff at the time, what are we doing to
alleviate the fears of Mr. Hanauer. You can make probabilistic numbers
prove anything, by which I mean the probabilistic numbers prove nothing.
That's not a very complimentary message for that term, and it imports
the feeling that the probability numbers, in this case trying to
eliminate the need for separation--electrical and equipment separation
criteria--that probabilistic numbers were being used to justify what
deterministically and the commonsense perspective of the people of that
era were using in order to avoid complying with safety criteria.
And with that, I would like to thank you for listening to
me. And does anybody have any questions?
DR. KRESS: Are there any questions of Mr. Atherton? Well,
we thank you, and particularly thank you for helping us on our time. At
this time, I -- we are scheduled to hear from another member of the
public, Mr. Paul Blanch, an energy consultant.
MR. BLANCH: Good afternoon. I am Paul Blanch. I am a
private consultant, and I'm not very popular. I'm cutting into your
lunch hour. I've also got a plane to catch, and I'm limited to 10
minutes. I will try to make this as brief as possible.
As an opening statement, I'd just like to say that, you
know, any views that I present here are those of -- my personal views
don't represent anyone else's opinion necessarily, certainly not the
opinions of Northeast Utilities, where I am an energy consultant for
their management.
Over the past few years, I've had a lot of interaction with
the NRC staff at many levels--in public meetings and private meetings
with the NRC staff--about the decommissioning. And it's more than just
the risk of zirc fire. I agree with Mr. Meisner, and also some of the
staff, that the real risk there is seismic--catastrophic loss of water
in the spent fuel pool is about the only issue in my mind that is
realistic that could cause a loss of water. We've looked at it at
Millstone or at Connecticut Yankee. We've analyzed the consequences of
a loss of water in the spent fuel pool and the consequences, because the
fuel has sat there for many years, the consequences are relatively
insignificant. That analysis isn't available.
What I'd like to do is briefly touch the overall regulations
governing decommissioning. I think in some respects we're losing the
forest through the trees, because there are many, many issues out there
in addition to the possibility of a zirc fire. The staff has proposed,
and it was alluded to earlier, the proposal on rule making under SECY
99-168, and I'm very supportive of this. I've made some comments at
previous meetings. And SECY 99-168, if you haven't seen it, is rule
making that covers all aspects of decommissioning for which there are
very few rules. And in going through the development of the rules, we
need to keep these NRC key messages in mind: to maintain safety, to
enhance public confidence, to improve effectiveness and efficiency, and
to reduce unnecessary regulatory burden. I'm very, very supportive of
all these aspects, especially the one on enhancing public confidence,
which we have not done a real good job.
The SECY 99-168, which is being considered -- and, by the
way, I -- this is the identical presentation I will be giving to the
Commission Monday afternoon -- has a five-year schedule. There are
issues, additional issues, that need to be addressed within SECY 99-168.
But the additional guidance provided will assist plants that are
presently going through decommissioning.
There are many issues here that I am just going to have to
glance over, but I'd be willing to discuss at a later time. Significant
issues that are not addressed properly for these plants that are going
through decommissioning. By the way, in the past two weeks, I've been
to four decommissioning plant sites--Millstone, Connecticut Yankee,
Yankee Row yesterday, and Maine Yankee last week, I think it was.
Issues that are not addressed that need to be addressed.
Site remediation criteria. The remediation criteria is 25 millirem by
the NRC, and I think the EPA says 15 millirem, but it boils down to
risk. I've looked at these numbers. I've received presentations from
knowledgeable people. I find the site remediation criteria of the 25
millirem to be acceptable from a risk standpoint.
Design basis accidents. What design basis accidents do we
have to consider. Peter Atherton mentioned criticality. He also
mentioned terrorism. What's the basis for doing away with emergency
planning. We need to define that.
Big issue here is the applicability of 10 CFR Part 50. If
we look at 10 CFR Part 50, and if you ignore the general design
criteria, the storage from high-level waste is not discussed; but, yet,
people are decommissioning their plants under 10 CFR Part 50. I don't
think it's totally appropriate. We need the regulations.
10 CFR Part 72 discusses the long-term storage of high-level
waste. 10 CFR Part 72 is not even being applied--at least the
site-specific regulations are not being applied to decommissioning
plants. I can envision in the future the way the staff is going right
now that we could have, for instance, Yankee Row 20 years from now still
having a Part 50 license and the only thing that's on site are dry cask
storage. It's just not appropriate. We need more definition.
We need consistent application of existing regulations. And
after these four plants, all I can say is, totally inconsistent
application of regulations in a security area; fitness for
duty--applicable in some plants, not applicable in other plants; quality
assurance, Appendix B -- everyone has a different program. And I'm not
saying anyone is doing it wrong, because I was impressed at the way
these various plants were doing it. All I'm saying is there's
inconsistency.
Emergency planning. Undefined. Fire protection.
Applicability of codes and standards. And many other areas that are not
defined.
We are regulating by exemption. We're taking parts of Part
50 and granting exemptions. I'm not saying it's wrong. We are applying
certain sections of Part 72 to various plants. There is a -- some
guidance out there. It's a NUREG. It's 6451. I right now couldn't
even tell you who wrote it, but it's a document that was put out about
two years ago. It does provide reasonable guidance for plants that are
going through decommissioning.
We have competing, conflicting regulatory mandates that need
to be resolved. We have the EPA's criteria and the NRC site remediation
criteria. That difference needs to be resolved. And one of the issues
that I'm bringing up is I think it's -- while the 25 millirem per year,
based on the resident farmer, is acceptable from a risk standpoint,
neither the EPA nor the NRC specify how much activity can be left on
site, either in concentration or total curies. By the regulations right
now, as long as I meet the 25 millirem three feet above the ground, I
can leave the reactor vessel buried. We need to be more specific.
We need to define what can be disposed of on site. When I
was at Maine Yankee, when I was at Yankee Row, there's a lot of clean
waste the staff has not been able to define what can be left on site,
even though it's clean, however you define clean. Certainly, I'm a
supporter of not going to additional expenses to dispose of clean waste
at Barnwell or Envirocare, but we need to define this. Again, the NRC,
EPA need to specify either average allowable concentrations or total
activity on site.
We need rules for long-term storage of high-level waste,
which are very clear in 10 CFR Part 72. We have the issue of a general
versus a site-specific license under Part 72. Again, most utilities,
although some of them have applied a site-specific license, most
utilities are planning to go with a general license, and essentially
store their high-level waste for God know's how long under a Part 50
license. Part 50, again, doesn't address high-level waste storage. And
then some licensees are applying certain portions of Part 72.
I'm a little repetitive here, but the general license, which
is being applied, 10 CFR Part 72, Subpart K, was really intended for the
storage, dry cask storage, of those plants that are continuing to
operate but yet have dry cask storage. The intent of that was never to
allow decommissioned plants to store high-level waste in dry casks
forever under a Part 50 license.
Alluded to before, all design basis accidents need to be
addressed, not only just the uncovery of the spent fuel -- they need to
be risk based. We do have to consider the zirconium fire, probably a
very low risk, low consequence -- well, it's not a low consequence
event, but it's a low risk event. We need, as Peter said, and some
other people alluded to, to address the potential for criticality. It's
happened. You know, someone asked regulators over in Japan two months
ago if it could happen, they would have said no. Stuff does happen. It
could happen while you're loading dry casks. Miscalculations of burn
up, et cetera. And we need to address are there other potential
accidents out there. I'm not sure.
DR. APOSTOLAKIS: Would you explain your first bullet a
little bit, please? What do you mean we need to be risk-based?
MR. BLANCH: What I'm saying here is that we need to look at
all potential accidents, and determine both the probability of their
occurrence, and the risk associated with -- or the consequences.
DR. APOSTOLAKIS: What you mean is that the risk assessment
should be complete?
MR. BLANCH: A risk assessment, yes. I think that's a hint.
DR. KRESS: I have a little button over here.
DR. POWERS: You attribute more control to us than what we
really have.
MR. BLANCH: I have some -- you can follow along here --
handouts. But let me go on in the interest of your time and my time.
My recommendations are to provide some interim guidance for those plants
that are undergoing decommissioning and NUREG 6451 does provide at least
a starting point
Again, a recommendation to the Commission is to direct the
staff to proceed with the rule making, as proposed by SECY 99-168; apply
site-specific requirements of -- and I say, site-specific requirements
of Part 72 to decommissioning plants.
My final slide is evaluate all potential accidents.
Establish clear site remediation criteria. Assure consistency, and
establish predictability. Money means a lot to these contractors that
are going into decommissioning. They want predictability. They want to
know what the regulations are and to work closely with all stakeholders
to enhance public confidence.
And I want to thank you for your time, and if I can respond
to any questions, I'd like to try.
DR. KRESS: Are there any questions or are you?
MR. BARTON: I think it was a pretty clear presentation.
DR. KRESS: Yes, it was pretty good.
MR. BLANCH: Thank you.
DR. KRESS: Well, I certainly want to thank all the
presenters and staff and the NEI for their presentations. At this time,
I guess we'll turn it back over to you, Mr. Chairman.
DR. POWERS: I'm going to recess us until 1:15 p.m.
[Recess.]
DR. POWERS: Let's come back into session. We are now ready
to turn to a subject that's going to be new to the Committee--the status
of resolution of issues associated with the design basis information.
And John Barton, you're going to take us through this subject, and tell
us what we ought to know.
MR. BARTON: Thank you, Mr. Chairman. The purpose of the
meeting is to continue our discussions with the staff and NEI on the
proposed draft Reg Guide, EG 1093, which the staff proposes to endorse;
NEI document 9704, "Design Basis Program Guidelines." At this point,
I'll turn it over to Dave Matthews to introduce the speaker.
MR. MATTHEWS: Yes, thank you. Stu Magruder, who's been the
lead project manager on this activity, will lead us through the detailed
briefing. I just want to indicate that we're here on fairly short
notice since the last time that we met. There were some outstanding
issues that we had discussed with the Committee. Both ourselves and NEI
have worked through those issues, and I believe at that juncture that we
left our last discussion there wasn't sufficient clarification for the
Committee to feel comfortable that they knew where we were. And our
purpose today is to update you, indicate that we've reached resolution
on these issues, and report on that resolution in the hopes that you'll
feel comfortable with confirming the staff's position on this.
MR. BARTON: Dave, is my understanding that the four issues
that we talked about last time have all been -- have come to closure?
MR. MATTHEWS: Yes.
MR. BARTON: At this point, the Reg Guide is not available
for our review, though?
MR. MATTHEWS: We haven't been able to write quite fast
enough to capture it in the Reg Guide, although the -- since we last
spoke, NEI has submitted a further revision, which you were provided.
MR. BARTON: We do have a copy of that?
MR. MATTHEWS: Right. And that, in effect, captures the
positions that the staff is in a position to endorse. So the Reg Guide
would -- although it would have, of course, the usual Reg Guide language
in it, the substance of any regulatory position is contained in the NEI
guidance document that we intend to recommend to the Commission
endorsement, but that's endorsement sufficient to provide opportunity
for public comment, because that's the -- we're at the draft
(**inaudible**) stage.
MR. BARTON: That's where we are. Okay, I understand.
Thank you, Dave.
MR. MATTHEWS: Okay.
With that, Stu, proceed.
MR. MAGRUDER: Okay. Good afternoon. I'm Strew Magruder
from NRRC, and I'll try to go through some of these early slides quickly
since we have talked about this a month ago.
Real quickly, the objective is to provide clear guidance on
the definition in 50.2. And just to refresh people's memory I have
included the definition from 50.2 as a slide here. We're not -- the
objective was not to change this definition. However, we may end up
there. I think it's important to talk about the relevance of the term,
because obviously a definition, by itself, doesn't have any impact on
what licensees do or how we regulate. So the -- I just want to
emphasize the places or the regulations where this term is referenced.
FSAR content -- obviously 50-34, the design basis, is required to be
part of the FSAR. And the distinction about whether information is
called design bases or other types of information really has no bearing
on whether it's included in the FSAR or not. We all agree -- we've
agreed early on that the information required to be in the FSAR includes
obviously more than design bases, and which bin you put it in is not
that important. So it's really no safety significance to calling it
design basis as far as it -- 50-34 is concerned.
50-59, effective probably around September of next year,
when the new rule becomes effective, there will be a new criterion
eight, which discusses the methods that are used to develop design
bases. These methods are those that are already included in the FSAR,
and we believe that the clarification of the design basis definition
does not alter the number of methods or the scope of methods that will
be included in the criterion eight or disposed of or evaluated under
criterion eight. So there's really no safety significance for this
application either.
The reporting criteria, the reporting rules rather 50-72 and
50-73 is really where the definition impacts most. And we'll talk about
that some more. Also -- it's also obviously mentioned in the GDC many
times, and Appendix B, Criterion 3, maintaining control of your design
obviously the term is used there also.
We also think that the term is helpful in understanding
degraded and non-conforming conditions in the plant. But it really has
more general implications there. Understanding the total design is
important. Understanding how obviously departures from that design
impact the overall operation of the plant is really what we're driving
at there.
DR. SEALE: It's really the baseline against which you make
decisions regarding degraded or non-conforming?
MR. MAGRUDER: That's correct.
DR. SEALE: Okay.
MR. MAGRUDER: That's correct.
DR. SEALE: So it's not an evaluative tool. It's the
baseline for the evaluation.
MR. MAGRUDER: That's correct. I could have worded that
better.
DR. SEALE: There's a distinction.
MR. MAGRUDER: That's true. Thank you.
DR. UHRIG: Well, it's also become, if I understand
correctly, a major issue on the plants that have had trouble--Millstone,
for instance, establishing the design basis was a major goal of the
recovery, was it not?
MR. MAGRUDER: Yes, that's true. And I think we have to
realize that we haven't always been careful about how we've used the
term design bases, and that's one of the reasons we're doing this
mission right here is that often times when we talk about design bases,
we include a lot of calculations and information that--
DR. UHRIG: is this different than what was involved at
recovery process?
MR. MATTHEWS: Yes.
MR. MAGRUDER: Yes, it is. This is smaller subset of
information. When we talk about design basis reconstitution, we're
talking about all the calculations, all the information that you need to
understand the design of the plant. And that's a much broader scope
than the 50.2 definition.
Dave, I think already covered a lot of this in his opening
remarks, but just to go through the issues that we discussed during the
previous meeting. The redundancy and diversity issue--basically NEI
agreed that redundancy and diversity were important parts of the design,
fundamental aspects of the design, and that should be included in design
basis information. They've update the guidance -- (**inaudible**)
submitted it October 28th to reflect that and to include a few more
examples about that to make it clear.
Normal operation. We basically reached agreement or
clarified our understanding that design basis values, bounding values,
can be produced or can come from normal operation as well as accident
conditions or AOOs so that we've expanded the discussion to include
that, to make sure that you don't preclude looking at normal operation.
Testing and inspection. The staff agreed that testing and
inspection were not functions that were performed by SSCs, but rather
functions performed on them. Therefore, the requirements for testing
and inspection, or testability and inspectability, were not part of the
design bases.
And design basis values is the one issue that has not
immediately resolved. It took a lot of discussion among the staff, and
we'll talk about that further here. But just basically, one afternoon
we resolved that issue.
MR. BARTON: Now is that issue, as you consider it resolved,
reflected in NEI's document? Are you guys going to address that?
MR. MATTHEWS: There wasn't any need for further revision of
NEI's document.
MR. MAGRUDER: Right.
MR. MATTHEWS: The resolution that took place was resolution
within the staff.
MR. BARTON: Okay.
MR. MAGRUDER: This is a -- the first bullet here is
basically just a restatement or a printing of what NEI has in their
guidance. And you'll see, I guess I emphasize that the values were
those that meet or are associated with functional requirements. That's
really where the staff had to think hard about that issue. There was
discussion, as you see, within the staff over which values to include,
and, as we discussed last time, whether the structural integrity of
piping was a design basis function or not; and, therefore, would have
values associated with it.
We have concluded, as Dave noted there, that the NEI
guidance does reflect an acceptable clarification of the definition and
maintains safety.
DR. WALLIS: What's the criterion for maintaining safety
when you reach this conclusion? What measures do you use to classify
yourselves as they maintain safety?
MR. MAGRUDER: We ran through the performance goals of the
NRC and decided that since the -- the really the -- the area where the
regulation impacts the most, as I said before, was reporting
requirements. And under the current reporting requirements, there is a
possibility that they'll be fewer reports made to the staff. However,
the reporting requirements are undergoing revision, and we believe that
the new reporting requirements will capture the information that we need
to regulate plants in a safe manner.
DR. WALLIS: So the basis is that there's no change in the
information available to the NRC?
MR. MATTHEWS: No, I think--
DR. WALLIS: That there should be no change in safety that
results from their decision?
MR. MATTHEWS: I don't think so. No, I -- let me take a
stab at clarifying. This is David Matthews. The conclusion is based on
the fact that the information will still continue to be retained in the
FSAR. There will still be treatment of that information within the
realms of the utilities' procedures for dealing with departures from
that information, even though it may not carry the nomenclature design
basis value. It may be referred to as supporting design information,
but that descriptive information and those parameters are still required
to be contained in the FSAR as part of the system component structure
descriptions required by 50-34A. So, therefore, the information and
departures therefrom will still be evaluated by the utilities in terms
of its impact on functionality and operability. And so our view is that
there is a continuity associated with that treatment.
In addition, design inspections and the oversight process
will still deal with the licensees effectiveness in dealing with
departures of systems and structure components from those design values
or those supporting design descriptions in the context of licensees'
corrective action program. So we saw a continuity--
MR. BARTON: Okay.
MR. MATTHEWS: With regard to that treatment that was
reassuring. But we do recognize that there is a possible perception
that the information that would come to the NRC by virtue of the
existing rules, which have the term "departures from design basis" in
it, might be limited. And that could have an impact in areas relative
to NRC oversight and could have an impact associated with public
confidence, given that the departures might not be reported to the NRC
as frequently by virtue of the definitional or nomenclature change.
We think the discussion with regard to not only the
appropriate amount of information that the staff might receive under the
revised definition is probably better had or better discussed in the
context of that reporting rule in determining NRC's involvement in some
of those departures than it is with regard to this issue.
So a portion of this concern we've translated into needing
to resolve in the context of the reporting rules, because we think
that's where the discussion ought to be entered. And that discussion is
insensitive to a definition.
MR. BARTON: I understand. Thank you, Dave.
MR. MAGRUDER: Thank you.
MR. MATTHEWS: Did I jump ahead on you there?
MR. MAGRUDER: Well, the next slide really covers the -- I
should have flipped the page. Next slide.
As Dave said, the belief -- we believe that the proper forum
for deciding what information we need or would be reported to the staff
is in the ongoing rule making on the reporting rule.
The recommendations, therefore, do -- to request the
permission from the Commission to publish the draft Reg Guide and
proposes endorsing the guidance, with no exceptions, and to solicit
public comment on that. The -- we intend to refer to the ongoing rule
making on reporting in the Commission paper in the Reg Guide and
indicate that the staff is considering changing the definition in 50.2
to more clearly define -- I'm sorry, we realize the definition is
ambiguous. It's open to many interpretations
MR. BARTON: Yes, we discussed that last time. I'm glad to
see that you're considering changing it.
MR. MATTHEWS: And that change may include its elimination,
depending on that relationship of that definition to other operative
parts of the regulation.
DR. POWERS: Are you going to -- I mean, changing that
definition in 50.2 is a rule making exercise, right?
MR. MAGRUDER: That's correct.
DR. POWERS: Dan, you're going to have to obscure that in
this publication for comment of a Reg Guide?
MR. MATTHEWS: Are we going to what, Dr. Powers? Are we
going to what?
DR. POWERS: Are you going to obscure that question?
MR. MATTHEWS: No, I think just the opposite. We're going
to identify that that's a possibility.
DR. POWERS: Yes, and in something by itself, or is it going
to be scrolled in with this Reg Guide that goes out for public comment?
MR. MAGRUDER: Yes, I think we intend to emphasize in the
Federal Register notice that when we publish the Reg Guide that we're
thinking about rule making. That's one option.
DR. POWERS: I guess I consider that not highlighting it. I
mean, it's a -- it seems to me that if you're going to change the rule
that ought to be something to stand alone by itself.
MR. MATTHEWS: Oh, maybe I didn't understand the question.
DR. POWERS: Yes.
MR. MATTHEWS: The rule making activity would be a stand
alone activity.
MR. MAGRUDER: Right.
MR. MATTHEWS: We wouldn't be soliciting comment on the
advisability of that rule making through the vehicle of this Reg Guide.
DR. POWERS: Yes, that's what I was concerned about.
MR. MATTHEWS: Yes, no, that's a good point. In fact, if
that would be inconsistent with the approach we're trying to take here,
which is to kind of divide and conquer this issue.
MR. BARTON: Right.
MR. MATTHEWS: All right. And one element of that would be
consideration on separate time frame of a rule making plan and
associated rule making package to address what we view to be frankly
shortcomings in the definition under 50.2, those shortcomings being its
ambiguity. And, in fact, that we've decided we can make a reasonable
interpretation of this as we have, and that NEI has articulated. But I
think there's other arguments that can be made to give you another
reasonable interpretation.
DR. POWERS: How did you get around having to do a
cost-benefit analysis on this change?
MR. MATTHEWS: I think on the rule change we would need to.
MR. MAGRUDER: We would, yes. Yes.
DR. POWERS: Are you actually going to do one? I mean, it
seems like a make-work sort of thing.
MR. MATTHEWS: There must be some to get around having to
do--
MR. MAGRUDER: One of the things we would like comment on is
whether it's an efficient use of resources to change the rule at all, to
change the definition at all. I mean, there's some debate about--
DR. POWERS: It seems to me that it's quite clear that
you've come up with a good reason. Yes, you've got to change this
thing. Everybody agrees to that. And there surely must be some way to
do it without having to go through a cost-benefit analysis that quite
frankly it can be you hook up anyway.
MR. MATTHEWS: Yes, there is, Dr. Powers. It would be
called an administrative change.
DR. POWERS: Yes. I think that--
MR. MATTHEWS: And I think that vehicle is available to us.
DR. POWERS: Good. Good.
MR. MATTHEWS: I mean, you would have to call it a back fit,
because it's a change--
DR. POWERS: Right.
MR. MATTHEWS: But it would be an administrative change.
DR. POWERS: Yes, but -- that's just going into -- that's
following a formalism that (**inaudible**).
MR. MATTHEWS: Right. No, I agree. And the fact that it's a
definition and not an operative part of the regulation would further
support that view.
DR. POWERS: I think -- that's good. I mean, it was just be
a manufactured cost-benefit analysis anyway.
MR. MATTHEWS: Right. We agree.
MR. MAGRUDER: The last slide there is a just a summary of
the next steps in the process that we have -- as you know, the paper
with the draft Reg Guide is scheduled to go the Commission by the end of
the month. We would hope to get approval from the Commission to publish
it soon after that. We're recommending 60-day public comment period,
which would mean that we'd be ready to come back and brief the Committee
again, probably in the May time frame, with the final Reg Guide
reflecting public comments.
MR. BARTON: Since everybody is in violent agreement now, do
we really need 60-day public comment on this?
MR. MATTHEWS: I would argue everybody would be an over
extension of what agreement has been reached.
MR. BARTON: No, just wishful thinking.
MR. MAGRUDER: There are still significant stakeholders out
there that I'm sure would like to comment on this.
MR. MATTHEWS: Many of whom have not chosen, in spite of the
opportunity to participate in these discussions--
MR. BARTON: Didn't think so.
MR. MATTHEWS: But that doesn't mean that we won't get that
involvement at a later date when we go with an actual Reg Guide.
MR. BARTON: Okay.
MR. MAGRUDER: That concludes my presentation, unless there
are any questions. I believe NEI is here, and would like to make a
short statement.
MR. BARTON: Russ (**inaudible**), and Tony, and I'm sure
that they're willing to share some--
MR. MAGRUDER: Insights.
MR. BARTON: Points of insights with us on this topic.
Disagreement. Well, they haven't been bashful on this issue before, so.
DR. APOSTOLAKIS: Well, many other times they have been
bashful.
MR. BARTON: Oh, lots of times.
DR. APOSTOLAKIS: You'd better start, Tony, because you're
going to hear a lot of these remarks.
MR. PIETRANGELO: Nice to see you again.
We don't have a whole lot to tell you. I think Stu's
presentation covered the--
MR. BARTON: Couldn't you just tell him that you really
think that PRA is a tool?
MR. PIETRANGELO: I told him that on the side yesterday.
Let me just start off by saying there's a lot of kudos that
have to go around from where we were last time, approximately a month
ago, to get to this point
MR. BARTON: Right. Right.
MR. PIETRANGELO: And I want to start with Russ. Russ has
been the project manager. He's chaired our task force on this.
MR. BARTON: Do you mean he finally got one right?
MR. PIETRANGELO: He's gotten a lot right lately.
DR. APOSTOLAKIS: We are on the record.
MR. PIETRANGELO: And we've had a lot of -- again, I talked
to you about this yesterday. We get a lot of industry participation.
This is an issue, just for a little bit of background, when I first came
to NUMARC in 1989, I was the project manager on the first design basis
program guidelines, so I have a little bit of history with this myself.
And we've had subsequent project manager, Adrian Heymer, and then Russ
picked it up about halfway through. And, you know, those of you who've
been at the plants and in the industry know this issue has been out
there for quite some time.
And it's been thorny. And that's why these discussions were
so difficult. But, besides Russ, we have to credit the staff. Stu, who
was just up here, and Cindy, and Scott Newbury, and Dave, and the rest
of the staff. This was a difficult issue. There's a lot of history
associated with design basis and we think we got it right. We think we
got it focused. We refuse to say that, you know, that's -- let's agree
to disagree. We kept at it and finally got to a point I think that we
can work with the documents and get them endorsed. So that kind of
never say die attitude got us to this point, and it's very easy to say
sometimes that let's just agree to disagree and bump it up the chain and
take an issue like this, both to the ACRS and the Commission and so
forth. And where we really should get it right at the staff level. So
we're very pleased about that.
Unless there's any questions, you have our October 28th
letter that has the latest revision of the guidance. Stu went over the
reasons why the term design basis and its interpretation is critical.
We kind of see it -- we've -- the last couple of years -- first we went
through, you know, the FSAR update process and got some guidance
endorsed on how to do that for 50.71(e).
Then we struggled with the 50.59 rule making, which this
Committee has had some hearings on. And now we're -- we got the rule
done on that, and now we're working on the guidance.
MR. BARTON: Right.
MR. PIETRANGELO: And got a ways to go on that one yet, but
it's proceeding well. In the meantime, we did the commitment management
guidance, another part of the licensing basis. And that's been
submitted to the NRC for endorsement. And this one, this design basis
guidance I think, you know, of the things we've worked on, each one is
important in its own way. It's kind of like the stool, whether you call
it three-legged or four-legged, you need all the legs. And without this
one, and without it being consistent and integrated with the others, you
just didn't have the stability that really has been the objective of all
these efforts. So, it was -- it made it worthwhile to keep at this one
until we got agreement, because, without it, it would have impacted all
the areas, too.
Again, unless there's any questions on the guidance.
MR. BARTON: Now, we hadn't seen the Reg Guide. As Dave
explained, they're still busy working on that, but I did review the
latest revision to your document, and thought that the changes you made
in here were appropriate and I thought this is probably where we would
end up. So I want to give you a lot of credit for coming and revising
that document, because I know we were at odds on the design basis
issue--
MR. PIETRANGELO: Right
MR. BARTON: A month ago, and it's good to see that we've
come to closure on that one.
Does anybody on the Committee have any other questions or
comments on this?
DR. POWERS: It seems to me that we've received a document
from (**inaudible**) group (**inaudible**) loudly protesting the NRC's
willingness to allow people to work or to operate what they call outside
the design bases. I was looking -- madly looking for that document to
see if people had seen it, but I can't seem to find my copy of it. Are
you aware of (**inaudible**) such a document?
MR. MATTHEWS: There was a document that does -- that has
come to the staff through several arenas, you know, okay; that raises
concerns that plants operating out there outside their design basis or
that are labeled as operating outside their design basis are by, almost
by definition, therefore, unsafe. But the staff has not examined that
document that I'm aware of.
DR. POWERS: Yes, I mean, it's a little bit on the
histrionic side, and it's -- it has its portrayal, but it looked like a
source of people that maybe you had not heard from in connection with
this that it might be worthwhile to hear from.
MR. MATTHEWS: Yes, that's why -- one of the reasons why
this particular -- the possible implications of accepting an
interpretation that in the reporting arena might result in reduced
reporting to the NRC, we intend to, in effect, focus on that area in the
Commission paper and in the Federal Register notice announcing the
availability of the guide just to make clear that we understand there's
a perception that that reduction in information has an impact associated
with people's perception on how deeply or at what level of detail the
NRC will be overseeing or regulating that activity. So we see the
connection there, and we're hoping to have that discussion in the
context of reporting requirements and the oversight process as opposed
to a definitional argument.
DR. POWERS: I remember now the title of the document, but
not the authorship of it. It's Amnesty Irrational, I believe is the
title of the document, but I'll--
DR. SEALE: Are you planning on looking into that -- those
allegations in an organized way?
MR. MATTHEWS: We have not defined those as allegations, but
I'm very careful not to respond -- to be very careful how I use that
term because if we were to infer that they were, indeed, allegations,
they would be entered into an allegation process that we would examine.
DR. POWERS: In general, the document has simply looked at
things that have come to the NRC through normal reporting routes. The
LERs's--
MR. MATTHEWS: In other words, it's an analysis of
information that is available to the NRC and is publicly available, so
that it isn't a document that, as I understand it, presents some
heretofore unknown information.
DR. POWERS: Simply looking at -- largely LERs I think, but
maybe a few others. I take it not so much as what it's talking about
there, which may be a little off the mark here, but the fact that there
is obviously a group of individuals outside of the drafting team here
that has an interest in not just the exact words, what the meaning of
the words are as well. And it might be worthwhile to react out to them,
because I think from their interpretation sometimes they may be
interpreting design bases a little bit differently than we interpret
them.
MR. MATTHEWS: We intend to do that.
DR. POWERS: Good. Good.
MR. MATTHEWS: I'd like to say by way of concluding remarks
two issues I'd like to mention: that the staff, as -- you know, it's
hard to reflect when you've put a line item on the viewgraph about, you
know, concerns within the staff. It's an awful shorthand way of
describing what were some very strongly felt views associated--
MR. BARTON: Yes, I'm sure -- I'm sure there were based on
the discussion we had about a month ago where--
MR. MATTHEWS: Associated with this issue, and I think it's
to the staff's credit that a, that when those strongly held views exist
that we have a forum within the staff to address them and deal with
them, not only internal to the staff, but also in connection with our
communications and public meetings with NEI, who are also open minded to
deal with all that is brought forward and prepare responses and
recognize that we're dealing with some strongly held views. So I think
the exchange inside the staff was informative, and I think NEI's efforts
to recognize those views and to respond to them, you know, was also to
be commended.
I also appreciate the discussion we had about a month ago
with the ACRS. I think I -- to be honest, as I left that meeting, I
guess I was disappointed that we weren't able to come to some agreement
with you all relative to our ability to just move forward and basically
say, trust us, we'll get this sorted out. I think there was a
reluctance on your part at that juncture because of what you saw to be
the disparity to do just that. And I think, to be honest, that prompted
us to move very quickly and to, once again, as Tony said, you know, go
back to the table and talk some more with the attempt to bring about
resolution.
MR. BARTON: And it looks as though you did that, because I
think the sense of the Committee was frustration. We knew that it could
-- that there was a resolution out there--
MR. MATTHEWS: Right.
MR. BARTON: And people were just dug in, and it was hard to
try to spread -- separate design bases from reportabilities and
enforcement and that kind of thing.
MR. MATTHEWS: Right.
MR. BARTON: And I think you -- both parties deserve credit
for coming to closure on that.
MR. MATTHEWS: I was only going to say, I wanted to thank
the Committee for your efforts in that regard. You brought some light
in an area that needed some more light. So with that, the staff's
presentation is concluded.
MR. BARTON: If there are no more comments or questions, I
want to thank the staff and NEI for their presentations and hard work
over the past several weeks.
DR. POWERS: Well, especially the hard work part.
MR. BARTON: The hard work.
DR. SEALE: Are you going to need a letter?
MR. BARTON: Dave, are you guys looking for something from--
MR. MATTHEWS: Yes.
MR. BARTON: The Committee that says--
MR. MATTHEWS: I think it would be helpful for the staff to
have that--
MR. BARTON: Okay.
MR. MATTHEWS: As part of the package that which is going to
go forward.
MR. BARTON: We'll prepare a letter that says, you know,
where we think this thing is ready for public comment or whatever --
I'll prepare a draft letter.
MR. MATTHEWS: And the fact that that letter might encourage
further public comment on this, given its sensitive nature that--
DR. POWERS: Well, I think the appropriate way to do this is
simply inform the Commission that we have no objections going--
MR. BARTON: To public comment at this time?
DR. POWERS: To public comment on this, and not highlight
any particular group and what not, but--
MR. BARTON: Yes, that would appropriate. At this time,
I'll turn it back to you, Mr. Chairman.
DR. POWERS: Fine. Thank you very much, gentlemen. I think
at this point, we can go off the transcription.
[Whereupon, at 1:52 p.m., the recorded portion of meeting
was concluded.]
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Page Last Reviewed/Updated Tuesday, July 12, 2016