Thermal-Hydrualic Phenomena -March 6, 2002
Official Transcript of Proceedings
NUCLEAR REGULATORY COMMISSION
Title: Advisory Committee on Reactor Safeguards
Thermal-Hydrualic Phenomena Subcommittee
Docket Number: (not applicable)
Location: Rockville, Maryland
Date: Wednesday, March 6, 2002
Work Order No.: NRC-265 Pages 1-25
NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers
1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005
(202) 234-4433UNITED STATES OF AMERICA
NUCLEAR REGULATORY COMMISSION
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ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
THERMAL-HYDRAULIC PHENOMENA SUBCOMMITTEE
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MARCH 6, 2002
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The Subcommittee met at the Nuclear
Regulatory Commission, Two White Flint North, Room
T2B3, 11545 Rockville Pike, at 1:00 p.m., Thomas S.
Kress, Acting Chairman, presiding.
THOMAS S. KRESS Chairman
MARIO BONACA Member
WILLIAM J. SHACK Member
JOHN D. SIEBER Member
VICTOR H. RANSOM Invited Expert
Paul A. Boehnert
I N D E X
AGENDA ITEM PAGE
I. Opening Remarks, T. Kress, Acting Chair 4
II. GE CPPU Licensing Topical and Associated 4
NRC Staff Safety Evaluation, Introduction
A. GE Presentation (Closed), I. Nir, GE
B. NRC Staff Presentation (Closed), J. Donoghue
2. Technical Issues
C. GE Presentation (Closed)
III. Subcommittee Caucus
CHAIRMAN KRESS: The meeting will come to
order. This is a meeting of the ACRS Subcommittee on
Thermal-Hydraulic Phenomena. I am Tom Kress, Acting
Chairman of the Subcommittee.
Other ACRS members in attendance present
today are Bill Shack and Jack Sieber, and Vic Ransom
is attending as an invited expert, shortly to become
The Subcommittee will continue its review
of the GE Nuclear Energy Topical Report, NEDC-33004P,
Revision 1, "Constant Pressure Power Uprate," and the
NRC staff's associated safety evaluation.
The Subcommittee will gather information,
analyze relevant issues and facts, and formulate
proposed positions and actions as appropriate for
deliberation by the full Committee.
Mr. Paul Boehnert is the cognizant ACRS
staff engineer for this meeting.
The rules for participation in today's
meeting have been announced as part of the notice of
this meeting previously published in the Federal
Register on February 19, 2002. Most of this meeting
will be closed to the public to discuss information
considered proprietary to General Electric Nuclear
A transcript of this meeting is being
kept, and this transcript will be made available as
stated in the Federal Register notice. It is
requested that speakers first go to a microphone,
identify yourselves, and speak loud enough so
everybody can hear you.
We have received no written comments or
requests for time to make oral statements from members
of the public.
I have no additional Chairman's comments.
Do any of the members have any comments that you wish
to make? Seeing none, we will now proceed with the
meeting, and I call upon Mr. Israel Nir, I guess, of
General Electric Nuclear Energy to begin. The floor
MR. NIR: My name is Israel Nir with GE,
and we will discuss today the GE BWR Constant Pressure
Power Uprate Program. We met with you back in January
of this year and spent four hours or more on this
topic, and today I am going just to go over a limited
portion of that presentation and a few limited topics,
and provide summary of what we covered in January.
I have a brief opening session, and then
we close and go over the GE Constant Pressure Power
MR. NIR: As I said back in January, GE
now has extensive analysis experience with EPU,
ongoing implementation experience, EPU being
implemented at ten BWRs, and NRC is now reviewing
applications for three additional BWRs.
We expect a high volume of applications in
the next several years. To respond to this
anticipated volume and to facilitate the NRC review,
we proposed a CPPU approach. It is based on our
experienced, focused on impacts related specifically
to power uprate and maintained safety margin.
MR. NIR: We initially met with you back
in June of 2001 to describe the approach. We
submitted the LTR, CPPU LTR, which I'll refer to as
CLTR, for NRC review in March of 2001. We received
significant feedback from the NRC. We revised the
CLTR and resubmitted in July of 2001.
We then received a significant number of
RAIs. They all were addressed, and in December of
2001 we sent addenda to the CLTR, which is the basis
now for the staff safety evaluation.
We met with you in January, as I mentioned
already, to discuss the CPPU and CLTR approach, and
also you heard the presentation from Clinton on their
EPU, which included selected CPPU topics.
MR. NIR: The GE program is a power uprate
program. It includes the stretch power uprate five
percent -- these were the initial power uprates -- the
EPU which was approved back in '98 with increased
power up to 20 percent of original licensed thermal
power; the thermal power optimization which is the GE
terminology to the small operator, up to approximately
one and half percent based on improved feedwater flow
measurement uncertainty; and finally the constant
pressure power uprate.
CHAIRMAN KRESS: Is 20 percent the limit
or are there plans maybe to go further later?
MR. NIR: We don't preclude that at this
point. We are asking for generic process to support
20 percent. We definitely see -- Some of the plants
are reaching their limits, and what I say about that,
there are some very expensive components that will
have to be replaced in order to move to a higher
So that is definitely a consideration for
the future. It will become more expensive as we move
to higher power levels.
MR. NIR: This is a summary of GE power
uprate experience. Most of the experience is five
percent. On the left you can see all the initial five
percent power uprates were done with increased dome
pressure to avoid replacing the high pressure turbine.
More recently -- or opening the steam path. More
recently, the five percent were done with no increase
in maximum operating dome pressure.
You also see on the righthand side the
extended power uprate experience. The last three
plants, Clinton, Brunswick and Browns Ferry, are now
in progress. Clinton and Brunswick have selected CPPU
topics, as you heard with Clinton and you will hear
with Brunswick, which is basically the same topics.
Browns Ferry will the first submittal that
will be fully based on constant pressure approach.
DR. RANSOM: How much was the pressure
increased in the ones in the initial?
MR. NIR: Those initials?
DR. RANSOM: Yes.
MR. NIR: Probably varies between 20 to
DR. RANSOM: Pounds per square inch, psi?
MR. NIR: I'm sorry?
DR. RANSOM: 20-35 psi?
MR. NIR: psi, yes.
MR. NIR: This final slide is -- again, I
showed you this in January. It just shows the GE BWR
contributions from power uprate to the US grid. Until
now, we added 1700 megawatts electric, in progress
another 800, and you can see that we still have almost
50 percent on tap.
That concludes my comments for the open
CHAIRMAN KRESS: So that's like five new
MEMBER SHACK: Yes. You can play with the
size of the plants.
CHAIRMAN KRESS: Yes, of course.
MR. NIR: Yes. It is significant. So
again, that concludes my comments for the open
session, and I am ready to move to the closed session
and discuss the constant pressure power uprate
MR. BOEHNERT: Okay, we are going to go to
closed session then. Anybody here that doesn't have
an agreement to be here to hear GE proprietary
information, please leave. Other than that, we will
go to closed session.
So, transcriber, please start a closed
(Whereupon, the foregoing open session
went off the record at 1:14 p.m. and went back on the
record at 1:55 p.m.)
CHAIRMAN KRESS: I guess we are ready to
turn it over to you, John.
MR. ZWOLINSKI: Okay, Dr. Kress. Thank
you so very much. I had a few opening remarks that I
wanted to present to the Subcommittee, and then get on
with our staff presentation.
For those of you who do not know me, I'm
John Zwolinski. I am the Division Director
responsible for the Division of Licensing Project
Management. Thus, all licensing activity that is
undertaken at NRR is processed within my division.
Power uprates are a form of licensing amendment and,
thus, licensing activities such as this are processed
within Projects with the support of our technical
divisions such as the Division of System Safety and
Division of Engineering and the Division of Inspection
Programs and their efforts.
The staff is here to present the review of
the GE licensing topical report on constant pressure
power uprate for BWRs. I did want to note for the
record that we have a number of the management team
with us in support of our staff.
Ms. Suzanne Black, our Deputy Director,
Division of Systems Safety and Analysis, is with us.
Mr. Stu Richards, the Project Director responsible for
plants in Region 4; Mr. Singh Bajwa, our Project
Director for plants in Region 3; and a number of our
first line supervisors that are integral to the
success of NRR's mission.
We have Dale Thatcher who is with the
Equipment and Human Performance Branch. We have Brian
Thomas from our Systems Branch. We have Matt Mitchell
from our Materials and Engineering Branch. We have
Corny Holden from our Electrical Instrumentation and
Control Systems Branch, and from Reactor Systems we
have Ralph Caruso seated at the table and Frank
One of the reasons I mentioned that our
management team is here in part is to provide visible
support to our staff and to demonstrate overtly to the
Subcommittee the management commitment made to power
uprates and to the CPPU project in general.
The CPPU topical report proposes an
approach for the submittal and review of extended
power uprate applications. It outlines what is
expected from licensees in their applications.
If a licensee follows the topical report
and provides the information identified in its report
as part of its plant specific application, the review
should be greatly simplified. Approval of the CPPU
approach would be a key change to the review of BWR
It presents a simplified approach compared
to that previously approved in topical reports known
as ELTR-1 and ELTR-2. Although the Clinton power
uprate submittal uses some aspects of the constant
pressure approach, it does not reference the CPPU
The staff -- does not reference to the
topical report. The staff expects the first submittal
based on the constant pressure power uprate topical
report to arrive in the summer of 2002.
On January 16, 2002, the Subcommittee
received a presentation from General Electric that
outlined the CPPU approach and presented details of
selected technical areas. In our presentation today,
the staff will address specific technical concerns
which we believe to be of highest importance, and they
have essentially been captured in the agenda that's
been developed in working with the staff of the ACRS.
We have with us, in addition to staff here
to present information associated with the agenda,
additional staff that have worked on this particular
review, should question exist. So we've brought much
of the team over, Dr. Kress.
As you are aware, the CPPU deviates from
the previously approved approach for extended power
uprates for BWRs. The staff will discuss this matter
in some detail. I will note that the staff has
invested considerable resources in evaluating the
basis for acceptance of this proposed approach.
The staff has also conducted on-site
reviews, traveling to General Electric and to other
nuclear facilities. The point I am attempting to make
is not only is our senior management deeply committed
to ensuring that this program receives the highest
amount of visibility throughout the staff and here
with the ACRS, we are committed to ensuring that we
perform first rate reviews and ensure the health and
safety of our -- is preserved in the processing of
these amendment requests.
With that, I would like to now turn the
presentation over to our plant project manager
responsible for this activity, Joe Donoghue. Joe will
provide an overview of the staff's efforts regarding
the CPPU topical, and proceed with introductions, as
CHAIRMAN KRESS: We certainly appreciate
your comments and do appreciate the fine level of
support you are providing to the Subcommittee and the
MR. ZWOLINSKI: Thank you very much, Dr.
Kress, and we'll be here tomorrow also.
CHAIRMAN KRESS: And in April?
MR. ZWOLINSKI: I believe there is a
session scheduled for April, and we will support that
with our team.
CHAIRMAN KRESS: That certainly is greatly
MR. DONOGHUE: Thank you, John. I think
my mike works. As you heard, I'm Joe Donoghue. I'm
the GE Project Manager in NRR. I just have a few
brief remarks to give you an overview of the staff's
review that is documented in the draft safety
As you've heard, this part of the
presentation is open. It will be followed by a closed
session by the technical staff, and I will just point
out now before I forget that on your handouts for the
closed session, you will see some brackets around some
items that were considered GE proprietary information.
You won't see them on the projection here, but we just
want to point that out to make sure everybody is clear
on the basis for the proprietary information.
Just in way of history, I wanted to
explain I think what you may have heard in the
previous presentation, that there is a revision to the
constant pressure power uprate topical that was
received in July.
There was a previous version that was not
the basis for the staff's review. It's the July
version. So if somewhere in somebody's cabinet they
have a March version, that is not what we reviewed.
Get rid of it.
In the past, as you are well aware -- the
Committee is well aware that the extended power
uprates that have been issued -- some examples I've
listed up there, were based on the previous ELTR-1 and
ELTR-2 documents, and you've heard that there are two
in-house now, two reviews in-house, Clinton and
Brunswick that I list here, that use some aspects of
the constant pressure approach, and the staff has been
starting to deal with these things on a plant specific
basis, but this topical report, as you've been told,
has a number of changes to the previous approach.
I'll just put some key ones on the screen
here for you.
MR. DONOGHUE: Basically, the first three
bullets address changes to what we see as the content
in the submitted information with the amendment
request. There's some details that you have heard
before from GE today, and you'll hear some more
discussion about that in the presentations to follow,
but those are some key areas that we see some
Then I list the last item there as an item
that we had to consider. The CPPU approach uses the
ELTR-1 and -2 approach for testing with this one
exception in large transient testing.
The staff previously approved -- reviewed
and approved the ELTR-1 and -2 approach testing
proposal, and staff has looked at this large transient
testing exception for CPPU and has found it
acceptable. However, today -- in today's presentation
by the staff we were not planning on discussing that
and wanted to point out the reason, being that we plan
on discussing it tomorrow during the Clinton
We understand that there's Committee
members that were keenly interested in hearing about
those details. So rather than being repetitive --
CHAIRMAN KRESS: Yes, and those members
will be here tomorrow, but are not particularly here
MR. DONOGHUE: So as long as that is
acceptable, this is all I'm going to mention about
large transient testing, unless a question comes up.
We have staff available.
CHAIRMAN KRESS: No, I think we will wait
until tomorrow on that one.
MR. DONOGHUE: Unless there's questions,
I'll go on. There's some basic effects that the draft
safety evaluation discusses of implementing the
constant pressure approach.
As you've heard, there's changes to the
power to flow map. You saw a presentation from GE on
some heat balance parameters that changed, and these
things lead too some reevaluations of safety analyses
that are required, and you will hear about those
details very shortly.
MR. DONOGHUE: This slide -- You've seen
the list of specific exclusions. So you are wondering
why Donoghue is putting this one up, because it
doesn't have any information on it.
I wanted to make sure we emphasized that
the staff considers these exclusions that apply to the
CPPU approach to be very important. We want to make
sure that in our safety evaluation we discuss these
They came up in the presentation you just
saw. They will come up again in the next presentation
in some detail. We want to make it very clear that
these exclusions have to be adhered to, to meet the
spirit of this simplified approach that's contained in
this topical report.
CHAIRMAN KRESS: Suppose a plant came in
and referenced the CPPU process and the topical report
and says but we don't -- this one exclusion here, you
know, the list that we were given -- there's one of
them here we don't conform to, and the reason is --
they give you a reason.
Is that going to be acceptable, as long as
they can justify not --
MR. DONOGHUE: I'll take a stab at it.
Then I think there's somebody else here at the table
that would maybe chime in.
I think the short answer is ELTR-1 and -2
are there. They are approved and available for the
licensees to use. If they want to have a power uprate
with other encumbrances -- maybe I shouldn't use that
word, but other changes that they are considering
besides increase in power, they can use that approach.
By allowing the CPPU approach to be
available, it's a simplified approach. That's the
impetus behind it. We are seeing that as a way to
make our review also somewhat simplified, but if a
licensee decides they want to do other things, I think
our short answer is use ELTR1 and 2. I don't think we
are going to be favorably inclined to consider a range
of options in between.
CHAIRMAN KRESS: CPPU, we heard, was a
subset of ELTR1 and 2. So if they say, well, we're --
the only difference between the CPPU that we are
addressing is this one item that -- So we are going to
still reference the CPPU documents, but we're going to
justify this one change.
MR. CARUSO: Dr. Kress, this is Ralph
Caruso. I'm going to give the next presentation, and
I thought I would jump in here.
The reason we approved topical reports is
to make staff reviews efficient and effective, so that
we don't have to review the same thing over and over
again. If anyone who references a topical report
decides to take an exception to it, they bear the
burden of justifying that.
CHAIRMAN KRESS: As long as they justify
MR. CARUSO: In the process of justifying
it, they also take the risk that the staff may reopen
the review and, as a result, they may not gain the
efficiency and effectiveness that they had hoped to
achieve by referencing the report in the first place.
CHAIRMAN KRESS: I think that's the answer
I was looking for.
MR. CARUSO: This is a general practice
that we have with regard to all topicals, and it would
apply here. So licensee can take a chance, and maybe
they will get lucky.
CHAIRMAN KRESS: We understand. I think
that was the answer I was looking for.
MR. DONOGHUE: Thanks, Ralph.
CHAIRMAN KRESS: Okay.
MR. DONOGHUE: The staff's review of the
topical report that was submitted focused on, as you
may expect, the differences from what was previously
accepted in ELTR1 and 2. Wanted to point out that the
staff in its review considered lessons learned from
other power uprate efforts, and the SE, the draft
safety evaluation, mentions the Maine Yankee lessons
learned, in particular.
I wanted to add here that the review spent
some time examining one of the key differences here in
the CPPU approach, and the staff acknowledges that
there is going to be some analyses that we would
normally expect to see in an ELTR1 and 2 based
submittal that will not be available for our review in
CHAIRMAN KRESS: We understand that, and
that is one of the points of debate among the
Committee members. Will that come up again either
tomorrow or in April, that particular aspect?
MR. DONOGHUE: I was going to add that
this point will be discussed in more detail in the
following presentations, because it gets into some of
the proprietary aspects of the information. But we
just wanted to emphasize it here, because it was an
important aspect of the review and took some effort to
come to some resolution on that.
MR. DONOGHUE: My final slide just
outlines what we expect to be the roadmap we would use
for conducting the submittals for CPPU for specific
plants. I think you heard a mention about a power
uprate safety evaluation report shell that GE
This shell, though it is discussed as part
of this discussion -- it's not -- It was not submitted
with the CPPU topical report. It is maintained by GE.
However, for plant specific submittal we will be
seeing the power uprate safety analysis report.
In that report, staff is going to be
looking for certain things. I list some of those key
items up here, which we started to discuss a little
bit today. We had to make sure we know what methods
are being used for the analyses, justification for
their applicability at the new conditions, and --
CHAIRMAN KRESS: You will ask for the
justification in this report?
MR. DONOGHUE: And you heard just a little
bit of discussion. There were some questions about
conforming applicability of these generic evaluations
that are discussed in the topical report.
Another important point to bring up before
I turn it over to the more detailed presentations is
that the submittal, especially this power uprate
safety analyses report, can be used as the basis for
the NRC to conduct audits of selected safety analyses.
You heard about the audits before. We
will discuss them some more today, and I think it's
going to be an important aspect of our approach on
Unless there's any questions, thank you
for your attention. I'll turn it over to -- Yes?
CHAIRMAN KRESS: For BWRs following this
approach, this pretty much serves the purpose of a
standard review plan for those?
MR. DONOGHUE: I would not venture to call
it a standard review plan. This is -- I think, as
Ralph expressed earlier, this is a method that is
being proposed to us to make the review -- the
submittal first, more simplified and, therefore, the
review, hopefully, more simplified.
It's not necessarily something that the
staff -- If we saw a submittal that said to check the
box for CPPU, we did it; would not necessarily get in
and take a look at it. This is an approach that we
find, if followed, if all the things are done that are
in the topical and we will discuss in our safety
evaluation are done, we can then accept for review.
MR. CARUSO: Also realize, Dr. Kress, that
this topical does not address technical issues that
have to be demonstrated to be acceptable. Those are
addressed in the other technical topical reports, for
example, for ECCS methodologies, for transient
methodologies, for design stress calculations.
Those are what the SRP generally contains.
The SRP generally contains technical issues. This is
a process document. So those standards that are
described in the SRP and that are accepted in the
various approved methodologies still apply. Nothing
changes with regard to them. This is a process
CHAIRMAN KRESS: The Standard Review Plan
you're talking about there is just the original
licensing standard review plan.
MR. CARUSO: Standard Review Plan which we
use right now to do ongoing license amendment reviews,
the applicable regulatory guides, and all of the body
of regulatory guidance that currently exists for
operating plants right now.
MR. ZWOLINSKI: And if I may, Dr. Kress,
and to the rest of the Committee, remind that we do
have an IOU back. We are evaluating the pros and cons
of a Standard Review Plan for this area.
CHAIRMAN KRESS: That was really one
reason I've brought the question up.
MR. ZWOLINSKI: Okay. And I think Joe and
Ralph pretty much answered how far this actually goes,
but this is really not going to supplant do we want a
Standard Review Plan for the entire area, as we
understand it. That's another matter.
MR. CARUSO: I will make the observation
that I believe that the purpose of the Standard Review
Plan was to ensure consistency in staff reviews, and
the use of this document does that, to a certain
extent. The fact that the staff went through the
process of reviewing it, and a large number of staff
members participated in that, also helps to ensure a
certain amount of consistency.
MR. BOEHNERT: We will go into closed
session now. Transcriber, go back to closed session.
If there is anyone here that should not be here,
(Whereupon, the open session went off the
record at 2:15 p.m.)