ML20217D434
| ML20217D434 | |
| Person / Time | |
|---|---|
| Issue date: | 09/29/1997 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| ACRS-T-3011, NUDOCS 9710030190 | |
| Download: ML20217D434 (112) | |
Text
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Official Transcript cf Proceedings O
NUCLFAR REGULATORY COMMISSION fiGST'- So //
Title:
Advisory Committee on Reactor Safeguards Thermal Hydraulic Phenomena Subcommittee TRO4 (ACRS)
RETURN ORIGINAL Docket Number:
(not applicable)
[ S SE 415 7130 THANKS!
Location:
Rockville, Maryland O
Date:
Monday, September 29,1997
)
jng WIC0 Co_py_- 20tair!
n y.. -
J0T.De jf0 Of {he Commlt[gg Work Order No.:
NRC-1254 0f6M -
Pages 1-86
$$h j@Al 97 929 h SEc-pp87a3bb T-:3011 PDR NEAL R. GROSS AND CO., INC.
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Court Regmrters and Transcribers O'
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1323 Rhode Island Avenue, N.W.
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DIsOLAIMER PUBLIC NOTICE BY THE UNITED STATES NUCLEAR REGULATORY COMMISSION'S ADVISORY COMMITTEE ON REACTOR SAFEGUARDS SEPTEMBER 29, 1997 The contents of this transcript of the proceedings of the United States Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards on SEPTEMBER 29, 1997, as reported herein, is a record of the discussions recorded at the meeting held on the above date.
This transcript has not been reviewed, corrected and edited and it may contain insecuracies.
O NEAL R. GROSS COURT REIORTERS AND TRANSCRIBER 3 1323 Ril0DE !sLAND A%T.h4 NW
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UNITED STATES OF AMERICA 2
NUCLEAR REGULATORY COMMISSION
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4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
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6 THERMAL HYDRAULIC PHENOMENA SUBCOMMITTEE MEETING 7
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0 OPEN SESSION 9
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10 MONDAY 11 SEPTEMBER 29, 1997 12
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13 ROCKVILLE, MARYLAND
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15 The Subecmmittee met at the Nuclear Regulat.ory 16 Commission. Two White Flint North, 11545 Rockville Pike, 17 Room T2B3, at 8:30 a.m.,
Thomas S.
Kress, Chairman, 18 presiding.
19 20 21 MEMBERS PRESENT:
22 THOMAS S.
KRESS, CHAIRMAN 23 MARIO H. FONTANA, MFMBER 24 DANA A.
POWERS, MEMBER
,m
( )
25 ROBERT L.
SEALE, MEMBFR NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE IS'AND AVE., N.W.
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1 ACRS STAFF PRESENT:
2 Paul A. Boehnert
,n
'N 3
ACRS CONSULTANTS PRESENT:
4 Ivan Catton 5
Virgil Schrevk 6
Novak Zuber 7
ALSO PRESENT:
8 Carl Berlinger 9
Ed Throm 10 Dan Prelewicz 11 Jim Gresham 12 Dan Spencer 13 Joel Woodcock rm(,)
14 Tim Andreychek 15 Bill Brown 16 George Yadiraroglu 17 Dino Scaletti 18 19 20 21 22 23 24
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25
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A-G-E-N-D-A
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AGENDA ITEM PAGE 3
Introduction, Opening Remarks, T.
Kress, Subcommittee 4
Chairman 4
1 5
Consultants' Comments, N.
- Zuber, I.
- Catton, V.
Schrock 5
7 NRC-NRR Presentation, C.
Berlinger, E. Throm 26 8
Westinghouse Presentations S
Meeting Objective, J.
Gresham 39 10 rest and Analysis Program, D.
Spencer 70 11 12 13 O
I LJ 14 15 16 17 18 19 2 ',
21 22 23 24 I
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1 P-R-0-C-E-E-D-I-N-G-S i
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(8:30 a.m.)
!O j
3 CHAIRMAN KRESS:
The meeting will now please 4
come to order.
This is the meting of the ACRS
+
1 5
Subcommittee on Thermohydraulie Phenomena, t
6 I'm Thomas Kress, Chairman of the a
7 Subcommittee. ACRS Members in attendance are Mario
..L 8-Fontana, Bob Seale and Dana Powers.
4 9
The ACRS Consultants in attendance are Ivan i.
l 10 Catton, Virgil Schrock and Novak'Zuber.
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11 The purpose of this meeting is for_the f
l~
12 Subcommittee to continue its review of the results of the i
33 Westinghouse test and analysis program being conducted'in 14 support'of the AP600 design certification.
During this l-15 particular meeting, the Subcommittee will review key i
16 elements of the Westinghouse passive containment system l
l 17 test and analysis program.
The Subcommittee will gather j
18 informacion, analyze relative issues and facts, and l
_19 formulate proposed positions and actions as appropriate as 20 deliberation by the full Committee.
Paul Boehnert is the t
(-
21 cognizant ACRS st.af f engineer for this meeting, p
f 22 Specific sessions held during this meeting
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23 will be closed to the public to' discuss Westinghouse
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j 24 proprietary information as so noted on the agenda.
25 A transcript of the meeting is being kept, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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thoroforo it's requeoted that the epackars first identify 2
themselves and speak with sufficient clarify and volume so 3
that they can be readily heard.
4 We have received no written comments or 5
requests for time to make oral statements from member of G
the public.
7 I'd like to remind the Subcommittee Members 8
and the consultants that we are dealing in this case with 9
an evaluation model, the GOTHIC, Westinghouse GOTHIC and 10 that means that it's a lot different than a best estimate 11 model because the ideas to have a conservative 12 demonstration that you meet the -- for the Chapter 15 13 design basis accidents, that you meet the figure of merit
(
14 which is the containment pressure in this case, and that 15 you want a conservative demonstration that pressure is 16 below the design pressure and that it gets down to at 17 least half the design pressore in 24-hours.
18 Before we start the formal presentations, I'd 19 like to call on our Consultants to make some preliminary 20 comments.
21 First, I'd like to ask Novak Zuber to make 22 some comments.
23 MR. ZUBER:
Thank you..
Two weeks ago I 24 attended a meeting with NRR and Westinghouse on Monday and
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25 Tuesday to listen in preparation for this presentation.
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I wao a little bit lost by the number of 2
documents and poor organization.
After I went home that O
3 ns.ght, I prepared a road map because the next day I was 4
going on a trip to be one week out of town, so I faxed the 5
road-map which was attached to your note; to Paul and I 6
was very pleased and would like to compliment Westinghouse 7
that they responded to this request or suggestion which is 8
in their own benefit to help us follow the development.
9 So 1-won't discuse the road map at all since they 10 presented one.
11 1 Now let me address the scaling.
It's usually 12 customary in engineering if you want to test a model or a 13 prototype you have something in mind.
I would like to 14 recall you to the large break LOCA when we designed our 15 facilities.
We wanted to preserve the power to volume 16 scaling and this was really the key to the success of 17 closing the large break LOCA.
This was not done in LST.
18 As they say on page E-5, LST heats sink area 19 to volume and floor history are not scaled to AP600.
It 20-is not really clear how was LST designed how they're going 21 to use it.
-22 On page -- of the executive summary, page 5, 23 it is stated that LST was scaled for times larger than l
24 4,000 to 5,000 seconds.
If you look at figure-3-4 on page
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25 3-7 of the new report or on page 6-4 of the old blue NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W, (202) 234 4433 WASHINGTON, JC. 20006-3701 (202) 234 4433 j
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rcport, thio is way bayond tho cocond pack.
So whct it l
2 means is we have really no integral data for the first or 7_
(' ')
3 second peak, pressure peak.
4 Yet, on the same page of the same validation 5
of the steady state implicitly validates the PRC equation.
6 The PRC is a transient equation ar.d I cannot understand 7
that statement.
Statements like this are indicative of 8
this report.
For example, on page 8 it states primary 9
drives break source, gas volume and heat sink area.
As 10 you go in the conversation I'm not very skilled.
11 Thin on the same page they say analysis shows 12 system pressure well scaled.
See Figure 11-1.
I looked 13 for this figure 11-1.
It.'s not in the report.
- Again, s
\\-)
14 this is an indication of how this report was put tcgether.
15 Now let me to go to some specific criticism 16 and I think some of those will also be taken by Virgil and 17 Ivan.
It is usually customary to really well define what 18 are your reference data, how you want to scale it.
In 19 steady state you usually try to scale your value between 0 20 and 1 because you know your boundary conditions.
21 In transient case like this one here, the only 22 thing we know is the initial conditions.
And the scaling 23 was not done using the initial conditions at all.
24 Actually, it's really not clear and I don't think it's (q) 25 really consistent how they define, for example, in one NEAL R. GROSS COURT REPORTERS AND TRANSORIBERS 1323 RHODE ISt.AND AVE., N W.
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ccso I teko it intornni onorgy cnd then they take a
,w 2
pressure difference, then for pressure of the steam it's a 3
B of the steam.
There is no consistency that one could
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4 really follow and appreciate the development, j
i 5
Consequently, what I would really like to see 6
in the presentation today, they would address exactly how 7
the reference value was selected and why they were C
selected.
It is my understanding from reading this 9
report, all of these celections were done using a code.
10 Where that code doesn't have the capability model, many of 11 these important phenomena, furthermore many of these 12 phenomena completely distorted.
What is really distorted 13 is the heat transfers that ovt. represer.ted the area to
/
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14 volume ratio is much larger in a small facility.
15 Therefore, the condensation rates are much 16 stronger and accentuated in this facility than in the real 17 reactor or real containment.
18 The argument to present we shall do bounding 19 calculations because this is not the best estimate 20 scaling.
Well, I don't understand what is the best 21 estimate scaling or any other scaling, to scale for some 22 closest.
They want evidently to use LST for some separate 23 effect test in a window which are not well defined and 7-which is really questionable.
24
(_)
25 What I would like for them to ac dress today, I i
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would liko to hacr juctificction how thaco bounding 2
calculations are going to be performed.
This is not done g'-]
3 in this report and evidently we shall have another meeting 4
on following the boundir: calculations.
5 The difficulty with this approach is that to 6
hear part of the story today which is not very 7
satisfactory you have to remember all these comments in a 8
month or so to addrese the bounding calculations.
You 9
don't get the whole picture so you can put the arm around 10 the problein.
11 When I read in this report the first time a 12 year ago and this time again, I was really impressed by 13 the number of pi groups do you have.
They didn't have
/
d 14 them, but neither did I.
It's a large number.
15 One other problem is not only is the 16 condensation area is much larger in LST than in AP600, 17 also the internal circulation phenomena are not well 18 scaled.
They're not even addressed.
For example, what I 19 found on table 11, they list all the distortion in the 20 vicinities and that's very nice.
They list them down.
21 The problem is all explanations are only qualitative.
You 22 don't have hard numbers to see, is it important or not.
23 Some of them are just plain arm waving.
24 The approach which was used by Westinghouse 7()
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1 LST and_thcn to uos the sama code to predict the AP600.
j 2
Well, some of these phenomena are ot well scaled. -Other
{
I i
3 phenomena the code cannot calculate well.
The question is i
j 4
what are we going to draw from these calculations?
I L
0 Therefore, I would urge Westinghouse to I
6 address this problem of distortions, shortcoming of the i
7 code, how the bounding calculation is going to be 8
performed and how they can justify using data frem a j
I 9
distorted f acility wit.h a code which cannot notice i.
10 phenomena to come to some conclusions.
11' With your permission, Mr. Chairman, I will not I
12 go_on to discuss-the regulations because I would like to 13 give them the opportunity present their -- and then 14 depending how they present it, I'd like to have 5 minutes 15 at the end to present my views on their approach.
16 CHAIRMAN KRESS:
We'll certainly allow that.
t i
17 Thank you,-Novak.
With that, I'd also like to call on i
l 18 next Ivan for some of his preliminary comments.
I 19 DR. CATTON:
Given the nice overview that 4
4 20 Novak has presented, what I'd like to do would be just 21 briefly walk through the two reports and sort of indicate 22 where I have some concerns and maybe Westinghouse can note
- I 23 these and at some poin*. during the meeting they could 24 address them.
25 I'll start with the PIRT report and that's
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_,,,_._.___.,___,.,,__-_--_m_-_,~
11 1
They give a list of phenoment and you really 2
can't disagree with it.
It's the next level that's O
3 importa.t and in this list I think th.st if you got a few 4
heat transfer fluid mechanics people together in about an 5
hour they would come up with that same list.
That's 6
another problem I see.
It's act Westinghouse's alone.
7 It never ceases to amaze me how mtch can be 8
made of a relatively straight forward exercise.
On page 9
2-4, it states that the large scale test for separate 10 effects correlation validation and GOTHIC code 11 validations, scaling has been used to confirm the PIRT 12 ranking and to specify the applicable data from the PCs.
13 By proper arranging of some of the test 14 prd' ? -
e.
it might have been possible to do this, but this 15 was nu,.
- done, A few more tests, I think, are needed, 16 wherein the energy and mass added are reduced by a factor 17 of 8 or so.
Some scaling should be done to determine what 18 tests rhould be run.
19 Table 2 1 lists important processes and 20 identifies tests yielding needed data.
It's noted that 21 the test data base includes HDR, BRMC, NUPEC and CVTR.
22 This is news to me.
It would be helpful to see how data 23 from such facilities will be used and how the data will be 24 chosen for. code validation.
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one dono~this in a couple.of NRC 4eports, I don't know, I-2 guess they're not available to Wentinghouse.
This was O
3 done for..RELAP 5.
4 The effect of hydrogen on containment heat 5
transfer points to LST for_the needed tests.
You-can't do 6
this unless the hydrogen distribution is measured and 7
scaling is properly done.
8 In section 2.2.3 it talks about condensation 9
tests.
These tests were a duct that looks like it was 10-about two meters long.
It had an inlet section of maybe a 11 little under a meter and then the test section.
Entrance 12 length-is 5.25 channel heights roughly.
It's not clear 13 what the tests mean, even the turbulent flow requires on 14 the order-of 50 plus channel-heights.
Unless something is
]
15 dramatically different than the brief description implies, 16 the tests will lead to grossly overpredicting condensation i
17 rates.
18
'The helium part of the test will serve no p
19 useful purpose.
To conclude that the helium is the same 20 as any other noncondensible flies in the face of other 2 11 evidence.
It's a diffusion-process right near the s
l-
- 22 interface and helium diffuses better than nitrogen and as 23 a result should have less effect than nitrogen.
These
. 24 things are,not the same, 25 I don't have the reference documents, but from q
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13 tho titloa I don't bolieva they address the appropriate 1
fs 2
issu9s.
v) i 3
In 2.2.7, large scale PCS integral tests, the 4
LST test cannot be shown to yield the data they are touted 5
to supply and I'm going to quote again, "long term heat 6
and mass transfer test data for a geometrically similar 7
model of the AP600 containment vessel, the test provided 8
experimental data for evaluating phenemena inside 9
containment and for determining the relative importance of 10 various parameters that affect heat and mass transfer, 11 both the inside and outside containment surfaces."
12 This cannot be shown to be the case.
The heat 13 in mass removal rates per unit area are similar to what we
,s t
t 14 expected on a full scale AP600.
For the small scale 15 system, the heat and mass removal is far more effective on 16 a per unit volume basis than the AP600.
This is like mass 17 transfer to a catalytic surface with instantaneous 18 kinetics.
19 Whatever gets to the surface will disappear.
20 A number of parameters need to be properly 21 scaled.
From the first law you find heat and mass removal 22 per unit volume.
Heat and mass added per unit volume and 23 there are other parts to this that if ycu write the first 24 law properly, it will appear.
Momentum added per unit
(,,
k/
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14 1-addad~ par unit voluma, buoyancy removed, j
=
O 2
Matching all of these above will yield the 3
appropriate time scale when it's appropriately dealt with.
4 I don't think it's possible to do that in an integral-5 facility and having words floating through a document that 61 imply =that it is, is not right.
7 I think the MSLB is adequately dealt with, 8
mainly because the momentum will stir the containment.
9 Let's see, I'm going to now talk about the 10 outer film behavior.
Now,.at the end of the document 11 there are, there's a summary of the experts' comments and 12 there are some of the-rankings that I disagree with.
I 13 have the number designation, but I didn't write down what 14 they said.
The first was 1-C and this had to do with 15 break momentum.
Break momentum will determine-air 16 entrainment and the air will be carried with the mixture 17 into the upper volume and this impedes condensation.
18 1-D, break source density tells you wLat the 19 buoyancy source strength is and this will, in part, 20 dictate recirculation and degree of stratification.
21 2-A, the experts may be right, but there is an 22 air transport process that is important because it will 23 dictate what the condensation rate is.
Once the time rate 24 of pressure. change is less than 0, nothing much matters.
()
25 Between the-two peaks blow down and the second peak, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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- 1 everything matters.
(-
2-Basically, you're dealing with a reflux 3
condenser with a-lot of air in it and nowhere do I see the 4
information that I would need that could tell me what the 5
heat, the_ energy and mass removal rate is is a function of 6
the amount of air, particularly when I have to scale this 7
to something that's 130 feet across at the base.
8 I have some comments on the other document 9
which was WCAP-14845.
I don't remember what the title 10 was.
The document differs little from early versions.
11 Westinghouse doesn*t seem willing to come to grips with 12 the fact that LST is not scaled appropriately.
Their 13 conclusions about the scaling are that and I quote again, 14 "the scaling comparison shows the dominant terms of the 15 source condensation and evaporation, all of which scale to 16 within 8 percent."
17 This has-been the point of ACRS discussions 18 all along and it goes back to the meeting in Pittsburgh 19 which was five years ago, about five years ago.
The 20 dominant-terms per unit volume need to be compared, not 21' the dominant terms _by themselves.
And when I looked at 22 this document again, you keep the parameter associated 23 with the time-rated change of pressure in front of that 24 term.
And so you don't get these things right.
25 I'd also stated that the temperature and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE, N W.
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16 1
condcn ction maccurcmanto from the LST providoo coma of 2
the data needed to understand and bound stratification in
\\
)
3 the AP600 evaluation model.
The last time we discussed 4
this with Westinghouse, there were no reliable 5
measurements for such conclusions to be reached and 6
further, the impact of two high a heat removal rate per 7
unit volume and its impact on stratification is not 8
discussed at all.
I do not agree with the conclusion that 9
LST data can be used to examine known lumped parameter 10 modeling biases in the bounding evaluation model.
11 A large number of pi groups are derived in 12 Chapter 6.
Westinghouse still ignores the role of volume.
13 All but one of these parameters should have volume in the
~J 14 denominator and they do not.
The analysis should evolve 15 about dP* by dT* and this is their equation 73.
They 16 should divide through by the terms that are in front of 17 it, then con pare terms.
18 Section 65122 deals with containment 19 stability.
There's a lot missing from the analysis.
20 First, there's no table of symbols to refer to, at least 21 not near th' equations.
Second, there is no indication of 22 where the velocity U naught comes from.
The steam release 23 from a break or from ADS 4 must find its way up, losing any 24 break flow momentum along the way.
Selection of the
)
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b3 ccvaro or not.
Furthcr, tho flow rctos in LST wara 8
(_'T times larger than they should have been to match the high 2
0 3
heat loss rates at the containment boundaries.
Varying the area through which the steam reaches the upper 4
5 containment will also change the stratification.
Table 6-
.c 6
4 should be revisited with proper values.
7 A better approach to the question of stability 8
would have been to use the results of Taylor and others s
9 directly rather than interpretations by Peterson.
The dimensionless parameters developed in the original papers 10 11 deal with questions about transition from momentum driven 12 to buoyancy driven flows.
It was found that buoyancy soon 13 overwhelms momentum under most circumstances.
This is not j'~h I
l V
14 a new problem.
Many, including civil engineers, civil 15 designers of sewer outfalls have dealt with it.
16 The discussion of how to calculate the 17 bounding value of the pressure is given.
Westinghouse 18 argues that if one estimates the containment volume 19 conservatively low, the forcing conservatively high and s
20 the heat and mass removal conservatively low, one will 21 obtain a bounding value of the containment pressure.
This 22 is certainly true.
The problem will be in establishing 23 what high and low are.
24 Conservatively low mass and energy remov (a) 25 rates are justified in Section 11.3.
Measurements of the
~-
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18 1: oteady. state condensation mass transfer inside LST are 2
used.
O Stratification measured in LST is used to validate 3
evaluation model results.
The-heat in mass transfer 4
coefficients are probably reasonable providing their 5
magnitude is related to local conditions, och temperature 6
and air concentrations.
Any statements about stratification derived from LST are probably wrong or at 7
8 least unjustified.
9 Statements about the area to volume ratio, not 10 impacting conclusions about separate effects results 11 reached from LST is naive.
It is the combination of A 12 over V and mass and heat removal rates that are too high 13 that is the problem.
The high rates will reduce the 14 stratification and hence the change the local conditions 15 where the transport processes are taking place.
16 The. conclusion reached at the top of page 12-17 2, the net effect of these is an evaluation model that 18 bounds all-the dominant processes so as to produce the 19 maximum pressure response is not supported by what is 20 found in the body of WCAP 14845.
21-Thank you, t
22 I hope some of these things can be addressed 23 during the next.two days.
24 CHAIRMAN KRESS:
Okay, now I'll call on Virgil 25 Schrock for some preliminary comments.
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MR.'SCHROCK:
Okay, wall, I'd like to make a
,9 f5w additional comments concerning some of the equations 2
'~'
3 that I have difficulty in accepting.
And I'd like to go 4
back one step to the review that we had on the other 5
scaling report, having to do with the' primary system where 6
the critical flow scaling was presented.
Critical flow 7
scaling doesn't appear in this report.
The mass and 8
energy input from the break are inputs to the model for 9
this, but of-course, they have to be right.
And I don't 10 understand the thinking here, about how the synergism 11 between containment and primary system in the long term, 12 when the pressure differences are smaller, how that really 13 comes into play and is adequately represented by this 14 combination of scaling and analysis, using different 15 codes, different kinds of codes and some case, best 16 estimate and others so-called EM.
17 But getting back to the critical flow 18 evaluation, I had written in the report after that 19 previous meeting that the scaling of the critical flow was 20 approximate.
I would like to-point out to Westinghouse-21 that that was a mistake on my part, that I should have 22 simply said that it's incorrect.
And for the following 23 reason:
the critical flow according to the HEM model, the 24 square of the mass flux is the inverse of the partial O
(,/
25 derivative of the specific volume with pressure at NEAL R. GROSS CoVRT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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20 1c constcnt entropy. - And it's that difficulty that-the 2
people doing this analysis have with the thermodynamics.
O_
3 In taking-partial derivatives of thermodynamic properties, 4
one has to be. careful to understand how those partial 5
derivatives:are taken.
6 In that report, they were presented as 7
ordinary derivatives and that leaves out a term which 8
arises which is the product of the VFG, the volume change 9
on vaporization times the rate of change of quality with 10-pressure at constant entropy.
11 That term is comparable in magnitude to the-12 term that is retained in Westinghouse's approximation and 13 moreover, it. changes sign and the low quality region it is p
14 a negative quantity.
In the-high quality region, it is a 15 positive _ quantity and so sometimes it's additive, and 4
16 sometimes-it's not and when-it's not then, of course, the 17 difference 1 reintroduces the issue of-is the' term that was 18 neglected, that,is, one minus the quality times dF 19 ordinary derivative of the specific volume of the liquid 20 with respect to pressure, that will.become significant as 21 quality approaches zero.
22-So there are things about the analysis that
-23 are questionable, in principle, and I think that that has
~
24 to be reexamined for the other report.
It has l) 25 ramifications-in connection with the present one.
For NEAL R, GROSS COURT REPORTER'
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- 21 1
cxamplo, when wa look at equation 34, it describes some of 2
the'most rudimentary thermodynamic relationships.
The 3-difference between CP and-CV for real fluids, real gases,-
14 it says CP is defined as partial of H with respect to 5
temperature.
No attention given to how that derivative is 6
taken.
The definition-is at constant pressure.
7 So we need a subscript on there, subscript P; 8
then, CV, the partial of U by temperature at constant 9
volume.
So we have two different kinds of partial 10 derivatives here which are algebraically combined in 11 subsequent line and treated as though they are the came.
12 of course, they're not the same.
So we end up with an 13 equation which is kind of nonsensical, that is, CP minus:
()
14 CV is the partial of P times V with respect to 15 temperature.
16
-It's a statement which, you know, if PV equals 17-RT, now-it's-unassailable,-but that's the ideal gas.
The 18 equations that are being derived are presumably for real 19-gas, not the ideal gas.
So my difficulty here is that 20 when I find things that are wrong about the most 21-rudimentary thermodynamic aspects of-the thing, and these 22 are presented as: equations that are the basis of the 23 ~ scaling, where is the confidence that the bottom line has 24 any significance whatsoever.
The equations have got to be
[~)\\
25 right, if the scaling is going to mean anything.
So this NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE 15 LAND AVE., N.W.
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y 22 1
is only an icolated example.
Maybe it doonn't figuro b
2 strongly in whether the final equations have any degree ~of
.O 3
validity or whether they don't, but the degree of confusion that's introduced by the excess complexity in A
15 the way this is presented shakes one confidence.
6 The modeling of the containment, I find still r
F 7-in need of a simple diagram.
You have a list of
{
8 assumptions on page 5-1 which was nice to see.
It does i
2 -
9 seem to be pretty complete, a3though it does not include 10 the use of the thermodynamic equilibrium constant for the l
11 water.
- Somewhere in the analysis an assumption has to be 4
l 12 made and-it usually is in relationship to the boundary 2
13 condition at the interface, the condensation interface 14 where the common assumption is that we have thermodynamic f
- 15 equilibrium between the vapor and the liquid at that-16 location and that relationship dictates what the 17 temperature of the interface is going to be.
18.
Now you've calculated or you present equations 19__
as though the calculation of mass transfer is done with b
20 pressure as the potential driving the mass transfer which-l 21 is certainly fine.
The difficulty here is that in this
[
- 22 application, the condensation is driven by surface 23 temperatures.
Surface temperatures together with other 3
24 resistances determine interface temperature in 25 relationship to the heat transfer process, but in addition NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RMODE ISLAND AVE., N.W.
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+,w
,~
-w.--
e-m
-ev, w
mw-
-m--
r-o rw -e yw.
--r T
23 1
to-that, you hava-the thermodynamic equilibrium constenu 2
at-the interface.
These two things ~have to be satisfied
- 3. simultaneously in order.to get the right rate of 4
condensation.
5
_I-don't think that it's a good practice to-6 couch this in terms of pressure difference for this-7 application.- I-would much prefer to see it in terms of 8
temperature.
It's not wrong to do it in terms of 9
pressure, but'now you're going to-have the difficulty of 10 what is the partial pressure at the interface which is 11-dictated by equilibrium constraints.
I don't see that 12 presented in the equation.
13 Correlations that are used are simplistic and 14 on the one hand we think we'd like to see a simpler 15 analysis, but on the other hand the difficulty of pulling 16; correlations out and throwing-them in out of-context can 17 lead to_ pretty large errors in the coefficients that you 18 get,-but what I see is equations that are for' forced 19 convection in tubes being applied where it's not forced 20 convection in tubes, things of-this nature.
21 I think a' diagram which shows what the model 22 is purporting to do would focus a little better attention 23 on what you're going to need for the different parts of 24 the containment boundary that have different temperatures.
25 It's not as though the boundary of containment, including NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W,
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24 all thoso' interior boundaries on heat sinko is isothermal 1
2 at any point' in time.
It's.not.
And that is a major 3
difficulty, of course, in completing a good analysis on 4
the system.
5 Uee of the assumption of constant film 6
thickness, especially one that derives from the -- an 7
assumption _that the film is everywhere laminar is "ery 8
questionable.
I mean I don't understand the incentive for 9-doing that, given the extensive algebra that is involved 10 in some of the other analyses, why one would make the 11 argument that the film thickness can be treated as 12 essentially constant everywhere, makes no sense to me.
13 Now I reread the RAIs that had been issued
()
14 over the last couple of years and I looked, as I read the 15 reports _for answers as to how Westinghouse had responded 16 to the RAIs.-
Now I'm sure the staff is on top of this and 17 understands in-their view how you've responded, but to a 18 third party that isn't into this on a day to. day basis, I 19 must'say there doesn't not appear to be a well-identified 20 link between important questions that-had.been raised by 21 the: staff about the analysis that needed to be addressed 1
22 to-make the thing satisfactory and how those things have 23-been addressed and are not satisfactory.
That it simply 24 does not come through to me.
()
25 I think that those are enough comments.
I'll NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS
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-25 certainly have many more to make.on the equations ao 1-f 2-' they're. presented and I certainly would grant that my I
N 3-present view on some of this analysis can be shown to be t
- 4 wrong with a more proper description of what Westinghouse s
5 is.trying-to say with this analysis.
However, at the 6
moment, I have to say I'm skeptical because I find things 7
that I cannot agree are fundamentally correct and how we
?
8 can take these things as starting points and end up with a g
i.
9 bottom line that's correct, boggles my mind.
10 CHAIRMAN KRESS:
I would like to ask the 4
i 11 Consultants not for a written list of these comments. You 4
12 guys talk a lot faster than I can written, so I didn't get 4
13 them all, but as the meeting goes on, near the end we'll 1
14 want some sorC of a written report and-at that time you i
15 may want to include those parts of your comments that you j
16 did not think were well addressed.
If your questions got 17 answered during the_ meeting, then there's no use to 18 revisit that.
So keep that in mind in terms of the final 19-product.
)
20 I will also now ask if any of the Subcommittee
'21 Members wish to make any comments?
Seeing none, I will i
22 now turn the meeting over to Karl Berlinger of the office l_
23 of Nuclear Reactor Regulation.
2A DR. CATTON:
Tom, this has to do with the 25 written report you just mentioned.
When do you want it?
i j
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-r-,-v r-.;
,-. - ~
~. - - - - -, - -, -
26
-1 CHAIRMAN KRESS:
We'11 discuss that --
2 DR. CATTON:
You want it yesterday.
~I 3
CHAIRMAN KRESS:
I've haven't thought about 4
it.
We'll discuss it later.
5 MR. BERLINGER:
Mr. Chairman, thank you very 6
much.
I want to just take this opportunity to thank the 7
Committee and their Consultants for their comments.
So 8
far, I'm sure that Westinghouse is going to have a lot to 9
say,-but the staff has some introductory remarks and staff 10 presentation this morning will be made by Ed Throm.
11 I again I have to say that many of the 12 comments that the Consultants this morning have presented 13 at the meeting are comments that have been raised by our O
!s,) :
14 staff and Mr. Throm, in particular.
I'm going to very 15 quickly turn the meeting over to Ed.
Thank you very much.
16 MR. THROM:
Good morning.
As Karl said, my 17 name is Edward Throm.
I work with the Containment _ Systems 18 and Severe Accident Branch in NRR.
19 The purpose of my short presentation this 20 morning is to more or less bring the Committee up with 21 what Westinghouse is doing and try to give you our 22 perspective on the regulatory l issues that we're trying to 23 address in this review.
24 As you know, the AP600 is basically being
()
25 reviewed under part E2 of 10 CFR where the major objective NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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27 1
is to look_at the performanco of scfety systema in an 4
j 2
appropriate combination of analysis, test program and 3
experience, to come to some type of conclusions regarding 4
the accentaoility of the testing program, the quality of the analysis codes being used for the AP600 and the 5
.i 6
acceptability of these codes for evaluating the design.
7 We're working basically with three of the 4
j 8
general design criteria in looking at this review.
-9 General Design Criteria 16 which concerns the peak i
10 pressure which for the AP600 is 0 ?sig.
GDC 38 which is 11 basically long term performance.to remove heat and to j-12 rapidly reduce pressure and GDC 50 which concerns leakage s
13-following LOCA which is, of course, part of the siting
(~)
(_,/
14 evaluation and GDC 50 also addresses conservatisms-in i
15 bottles and inputs'in that evaluation.
16 Guidance provided to the staff is found in the f
17 standard review plan in three sections.
There are 18 descriptive methods for doing LOCA mass and energy 19 releases and steam line or secondary side' break mass and J20 energy releases and of course, the driving situation is to i
21 look at the dry containment and the guidance there is to 4.
22 look at those assumptions made in the analysis to 23 conservatively predict the pressure and as Dr. Kress
[
24 earlier said, there is a guideline in the standard review
()
25 plan that looks at meeting an objective of being at about NEAL R. GROSS
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COURT REPORTERS AND TRANSCRIBERS 3
1323 RHODE ISLAND AVE., N.W.
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.~.
28 g
1 ono half of tha:psak calculated pronouro at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
0 This is an objective of the AP600, but not necessarily a 2-
)
'3 requirement.
The AP600 when they do their siting 4
evaluation, they will consider leakage from-' containment at 5
the full 45 psig for the duration of that calculation.
6 They do not need to demonstrate that they have met the one 7
half of the peak pressure at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
1 8
We'll see more of that, I guess, in December v
i 9
when we really talk about the application of WGOTHIC to 1:
i i
10 the AP600, 11 I'll make one more comment about WGOTHIC.
The 4
12 only thing that really distinguishes WGOTHIC from GOTHIC 13 is Westinghouse's addition of the Clime model which is a
. 14 heat structure to characterize the PCS performance.
15 Westinghouse has not made any other changes to the 16 fundamental coding in the WGOTHIC code.
17 Okay, there are basically two reports that i
18 will be discussed during this meeting.
-There's the 19-Accident Specification and Phenomena Evaluation report-20 which-is 14812.
In that report, Westinghouse is 1
21-evaluating testing, scaling, sensitivity studies and 22 experts review in ranking phenomena that are important to 23 understanding the AP600-performance.
At the staff's-24 request they have added more to the PIRT process, if you 25 want to call it that, than would necessarily be there and i
NEAL R. GROS $
COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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- - - =
,n-,.
29 1
this is port _of.our-attempt to gat them to addrons more or less in one place-how the ersluation model is built upon
.2 3
the phenomena assessment.
4 So they have sections at the'end that address 5
how the test experience is being used to develop the 6
evaluation model in terms of modeling guidelines which may 7
be applying factors to correlations to be conservative or 8
the selection of conservative input conditions.
l 9
.on occasion, sensitivity studies are done with l
10 WGOTHIC to validate some of the ranking or to determine 11 which is the-most appropriate way to go to maintain a i,
12 conservariam in the evaluation model and they try to
~
13 address the uncertainties and' distortions and these j
14 basically deal with the correlations that-are being used
).
j 15 in distortione in the LST when LST information is being 16 used *.o justify or understand the evaluation model.
~f 17 The second report, which is the major report, 18 the large scale ':est facility scaling evaluation, and this 19-is basically Westinghouse's. objectives-as stated in their 20-report.
What their scaling approach'is and I would just 21 like to emphasize that what Westinghouse is working on now 22 is justifying a conservative evaluation model.
They are 23 trying to evaluate distortions in the LST, questions in 24 the LST which may not be fully addressable by the LST as a (O,/
25 test facility to understand biases.
Part of those biases NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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m _.... _. _.
.m._.__
30 1
coma into the use of the lumpsd paramster approach in ths 2
WGOTHIC code.
,-/,
j 3
-A number of years ago, Westinghouse was i
4 looking alt-what was called the distributive parameter i
5 model, in that particular code which put mere importance 6
on understanding local variables.
With the model they're 7-using right now, that level of detail is not deemed 8
necessary,.so what we're basically wrestling with is the 9-understanding of the evaluation model and whether or not 10 it's justifiable.
11 Within the scaling, they have a bottom up 12 component level scaling and we think that the LST has some 13 usefulness.n that evaluation.
On the other top-down 14 system level scaling, the staff still believes that there 15 are deficiencies in the LST when it's used for a full top 16 down evaluation and I think the Subcommittee Members have 17 addressed similar comments that t he staff has in those 18 areas.
19 DR. CATTON:
The staff believes LST is useful 20 for bottom up evaluation.
Could you expand a little on 21 that.
22 MR. THROM:
I'd like to defer to Scientech, if 23 I might.
- 24 DR. CATTON:
That's fine.
!Q 25 MR. THROM:
Okay.
Dan Prelewicz.
NEAL R. GROSS COURT REPORTERS AND ThANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-_m._.
m
,_m...
._-u__,
_,m
31 1
MR. PRELEWICZ:
Thic ic D n Prolowicz from 2
Scientech.
We're working with the NRC, helping them to do
\\)
3 the review.
I think you hit on the question, the heat 4
transfer correlation that they've used in whic;1 which 5
is from the literature and which they've compared to both che Wisconsin data and the LST data is based on similarity 6
7 variables and provided you have the right boundary 8
cendition, we believe they've shown that it's 9
conservative.
10 The question then comes down to how do you 11 show that they've got the right boundary condition on the 12 interior, in other words, the right local conditions on 13 the interior.
So we believe it's useful from the bottoms
-p)
\\_/
14 up approach for showing that the correlation is bounding, 15 but it pushes it into another area.
In other words, how 16 do you get the right boundary condition, the right 17 concentration of noncondensibles to use in that 18 correlation.
19 DR. CATTON:
I still guess I just don't 20 understand.
In the LST, I don't believe they measured 21 properly the distribution of air, so you really don't 22 know.
So what do you do with the result and how do you 23 make the connection of the scale of the tests, the other 24 tests that you mentioned is far different and now I have a (3_,)
25 surface inside this containment where I really don't know
/
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I 32
-1 what'o going on and-I'm to' drew a conclusion about 2
usefulness and separate effects.
I can't do that.
I
-3 can't make the connection.
4 MR. PRELEWICZ:
You don't agree that if you have the right boundary condition that that will_give you 5
6 7
DR. CATTON:
Oh, you bet I do. You bet I do.
8 I agree with that, no problem.
9 MR. THROM:
That's all we're saying, that if 10 they have the right boundary condition and we haven't 11 agreed with them, that they can prove that they've got a bounding -- that the way they're using it they've got a 12 13 bounding condition for the way they're using it-and AP600.
(m,/
14 DR. CATTON:
I'm getting lost here.
15 MR. ZUBER:
This is the core argument was that 16-if they have the bounding conditions they don't have it.
17 The point is that the area is distorted, condensation.
18 You have much more area to condense.
Flow inflow from the 19 break is not scaled.
You have different circulations.
20 There is no way from this report that you can say these 21 data can be used for separate effects.
I didn't see it.
12 2 I wish they could show it.
I wish you could prove it by 23 going, if they show it -- like if I was an emperor I would
- 24. have money or something like that.
()
25 DR. CATTON:
If they would have put more NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHoDE ISLAND AVE. N.W.
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33 e
IL instrumantation insido end you know local conditiono you might be able to. draw some conclusions, but they didn't.
2 3
3 MR. THROM:
We're not really prepared today to 4
_4 go into detailed discussions --
~
5 DR CATTON:
I understand.
I'm just trying to
}
6 get all of these things on the table.
7 MR. THROM:
Yes sir, i
8 MR. PRELEWICZ:
Ivan, can I bring up one more j-9' point?
Would you agree that if in both cases, in the LST i-10 and in-the large containment that the containment was very
/
11 well mixed, in both cases.
If you could show that,
- 12. wouldn't that be -- wouldn't that basically be a good 13-bottoms up scaling?
You know you've got the right.
()
, 14 boundary condition because it's the same in_either cas4.
15 If it was totally well mixed in either. case, AP600 aad the 16 LST, totally completely mixed, you'd be okay.
17 DR. CATTON:
I guess this is.really the heart.
la I mean this is the-fundamental issue.
19 MR. PRELEWICZ:
That's the fundamental issue.
20 DR. CATTON:
Is how well mixed it really is 21-and sure, there are other differences.
-The fact that 22 the running length,.on the wall, it's kind of a boundary 23 layer effect.
Something is happening that depends on 24 what's gone before when~I go upstream, but I could see
()
25 where if you_show that it's fully turbulent and all this, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE.. N.W.-
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34 it bacomaa indspondant of-tha line, you'could meko all 1
2 these arguments, but the right kind of tests weren't run 3
to do that.
That's the problem.. If they would have 4
measured,;nevertheless, the LST because of the heat 5
addition and mass addition per unit volume and the heat 6
removal rate per unit volume were grossly distorted on the 7
high side, this itself tends to enhance the missing 8
process, so I don't think you can draw very good 9
conclusions.
10 MR. THROM:
And I don't believe via the 11 scaling study or the LST they're trying to make those 12 conclusions.
I think --
13 DR. CATTON:
I read some quotes from the book
)
14 and they are, unless they're reports, I' don't know what Co 15 say.
I read the report, the report draws these 16 conclusions and I quoted them for the record.
I' not 17 involved in day to day with Westinghouse, so I don't know 18 what they're thinking.
All-I know is what they wrote.
19 MR. THROM:
- Right, 20 DR. CATTON:
And what they wrote, they draw 21 these conclusions.
And they draw them very strongly.
(
22 MR. THROM:-
I understand.
23 CHAIRMAN KRESS:
Ivan, have you looked at 24 Section 9 of the report on the application to AP600 of the 25 test and analysis?
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35 1
DR','CATTON:
Which report'is it in?
~
2 MR._THROM:
14407.
It's the'two volume 4
s -
l 3
report.
4 DR. CATTON:
No.
5 MR._THROM:
In terms _of.some of the difficulty 6
with the documentation, you need to almost have 14407 --
L
-7 CHAIRMAN KRESS:
You really need to look at 8
that section 9.
9 MR. THROM:
As part of the information.
And I 10 guess the'best-way to try to put a story together on your 11 own, if you want to is to attempt to in the PIRT report, 12 14812, start looking at the section called the 13 implementation and the evaluation model.
That 14 unfortunately will on occasion take you to chapters'in 15 WCAP 14407 where, for example, circulation is a big issue 16 on the AP600 and the LST, so they have? additional 17 information provided for 14407 and once you read 14407,
'18 then maybe you can come back to the PIRT report and agree-19 with statements that are being made or disagree with them, 20 but the story is not always complete in that particular
'21 document.
22
'So-there-'are three driving documents, 14407 23 which is called the-applications,'WGOTHIC to the AP600, 24 and there's a wealth of'information in that report _that
_25 really needs-to be factored into understanding the full
~
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- -3 6 1~
davolopmant'of tha.ovaluation model.
2 DR'.'CATTON:
Well, I did read something about 3
that in these two reports.
The two reports I read were-4 the 14012 which-is PIRT and then the_ scaling report.
And 5
in it they claim that they have made the arguments that 6
justify the way they choose these parameters, energy and 7
mass and so forth.
In my view, they have ^.ot.
8 MR. ZUBER:
You see the difficulty, Ed, what 9
you're saying is just what I mentioned before.
This is 10 something we are going to discuss maybe a month frem now, 11 maybe two months from now.
See, we are now discussing two 12 reports and you are trying to justify based on the report 13 which we are not discussing today.
7k,,/
14 MR. THROM:
Well, my hope is that AP600 will 15 bring in that information as they go through those 16 critical issues on this report.
Tomorrow is really kind 17 of from an agenda perspective to look at WGOTHIC,'the 18-limitations in WGOTHIC, limitations in using the lumped 19 parameter approach.
I'm not sure how far we'll get into 20 that information, but there are areas that from the
-21 staff's perspective we're looking at 14407 to try to find-22 the additional information that may be really being 23 referenced in the report.
It's a documentation issue
-24 right now.
Also, as Dr. Schrock said, we've been going
()
- 25 through an extensive RAI-process on this design and there NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE.. N.W.
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37 1
havo boon a lot 1 of questions and most of those answers 2-have comeTin late in August.
I think we finally got the O
3 last set in.
So we have an-enormous amount of work in 4.
front of us to determine whether or not the-responses to
~
5 the RAIs are meeting expectations, 6
DR. CATTON:
See,-I'think the thing that 7
perplexes me the most is this is not a simple problem.
8 mean a reflux condenser where you're putting too much air 9
in-it is not a simple problem.
And we all.know what the 10 impact of air is on a system like this and a beautiful 11 example is a heat pipe. -You bleed a little bit of air 12 into a heat pipe that's operating so that it glows red and 13 you watch the'end go black.
It does this because air 14 blocks condensation.
Any known condensible does some more 15 than others.
16 MR, SCHROCK:
And a lumped model isn't going-17 to do the job for you, 18 DR. CATTON:
See, if you choose to address a i
19 problem like this, you do the best you can with your i
20
- numerics, If you don't want to do that, you do the best i
21 you can wJth an experiment.
And what we're faced with is 22 neither.
The tool of choice maybe could do it, but 23 they've chosen not to.
The data is in it and some that 24 were mentioned by Virgil where they take correlations from
'A l (,)
25-physical circumstances that are not correct for the I
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38 application.-_Now you tell me you're going to choona a 1
2 value of this coefficient that's conservatively small.'I 5
3 ask how.
You don't know what it is.
How do you know it's 4
small?
5 I don't know how you do that.
So if you want 6
to-bound this system, you've got yourself a real problem.
7 I don't know how you're going to do it, unless you can 8-somehow bring a lot of data together.
And we had -- this 9
Committee made suggestione -- I guess it was the 10 Subcommittee meeting that was almost five years ago, 11 things that could be done.
12 There's a lot of information available, but 13 somehow al systematic approach to bringing it into the
()
, 14 right arena needs to be done and it hasn't.
You read 15 these documents that are supposedly to set the stage to 16 accept what comes next and you can't agree with it-How 17 can you deal with what comes next?
I think inappropriate 18 conclusions need to be removed from this report.
This 19 report is going to become part of the certification 20 package, isn't it, the two reports we have?
21 MR. THROM:
Right.
22.
DR. CATTON:
If that's the case, I don't think 23 you can put this in a public arena.
People who are in the 24 business of heat transfer and fluid mechanics just won't
()
25 accept this.
I don't accept it.
I think it's got to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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_ _.. _ _ ~ _ _
39 1
chongo.
1 2
MR, ZUBER:
Some of these comments, on one O
t
-3 page you say, for example, LST's valid for transient after 4
4000 seconds.
This is beyond the first and second peak
(
i 5
and we are interested in the first and second peak.
What l
6 data do we have to' test our codes?
We don't have data.
I i
7-If these experiments are well thought five a
8 years ago or if they had listened to some of the comments l
9 we had been making during'the last-five: years, maybe we k
10 would be in better shape,-but what you really ask-now, 11 review two documents, when we raise these questions-we are i
12 told no, you have to look in another document we are going 13 to be discussing a month from now.
Based on what we have i
14 heard, I agree with completely with Ivan.
S 15 DR. CATTON:
Maybe they should run a few more 16 tests.
I heard that the Italians are using your facility, f
17 Is that correct?
18-MR. GRESHAM:
Yes.
Thir is Jim Gresham from 19 Westinghouse.
Yes, the Italians did run a test to look at-s 20 a different kind of cooling system and they made 21 modifications to the facility and:ran it under that other 22 configuration.
i r
23 DR. CATTON:
So the facility is still l
1 24 operational?
I I
25 MR. GRESHAM:
Yes, as far as I know it's still i
NEAL R. GROSS l
l-COURT REPORTERS AND TRANSCRIBERS r
[-
1323 RHODE ISLAND AVE _ N W.
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.,--,y,.:c,m.,
.:--ey.,.~m.,,w,y.,
+ -,,
,y.
w.+,,,._,ww..-,,,.,w-mr,,,..,,,.
.-,--,--,y.-
..,--,,w.-,.-
,,,..,my..,,-,.
.w.wy.,--
,.--.,,.,-.-.3-a:
l 40 1
-- thoro hevo bacn ch:ngoc mnde to it, to look at this l
2 other cooling system, but the tank is still there.
,s
(
)
3 MR. THROM:
That's the only remarks I have to 4
make at this time.
5 CRAIRMAN KRESS:
Okay, I guess we're now at 6
the 9 o' clock -- no -- yes, I guess.
It's time for a i
7 break?
It's a little early for a break.
Why don't we go 8
ahead with the Westinghouse presentations and get those 9
started first.
10 MR. GRESHAM:
My name is Jim Gresham.
I am 11 the Manager of the group reFponsible for the containment 12 analysis at Westinghouse.
And over the next two days we 13 want to talk to you about, predominantly our PIRT and (3
( -)
14 scaling information.
The objective is to demonstrate that 15 the data base that we've used for validation of our 16 evaluation model is sufficient to support the use of data 17 evaluation model to calculate a conservative pressure for 18 the AP600 containment.
19 Dr. Catton mentioned he doesn't see how we're 20 going to do it and it's our goal cver the next two days 21 and following up with a subsequent meeting in December to 22 show you how we're going to do it.
l 23 I don't want to belabor the agenda, but just 24 briefly, later on this morning we're going to talk about
()
25 the PIRT, the process that we used, going through that HEAL R. GROSS COURT REPORTERS AND TIMNSCRIBERS 1323 RHODE ISLAND AVE., N W.
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41 l
1 offort cnd ttlk cbout tha high end m dium rcnk phonomanon 2
and talk about the scaling.
We're both looking at range
,()
3 of parameters and the system level scaling.
4 Tomorrow, we're going to talk about how the 5
evaluation model is used, what our approach is, what the 6
requirements are and as mentioned this morning, we're going to get into some of the limitations in lumped 7
8 parameter codes and how we handle that.
We'll talk about 9
some features that we handle within the GOTHIC code and 10 also some features that we handle outside the GOTHIC code 11 doir.g that.
12 Also tomorrow we're going to talk about the 13 data base that we use for circulation and stratification, o(x,)
14 That's come up a couple of times this morning.
Our 15 approach is to talk about the PIRT and the scall"g and 16 somewhat on the data at this meeting.
And the meeting in 17 December, we're going to talk about WGOTHIC code and its 18 description and also talk about how we apply that code.
19 That gets into the applications report as Ed mentioned.
20 As Dr. Zuoer noted, you can't you're not 21 going to hear the whole story on our whole package in juat 22 the meeting that we have here.
There is not enough time 23 to cover the whole story in two days and a meeting has 24 been tentatively scheduled for December, to complete that
~
' ^)
25 effort.
I kind of got ahead of myself.
Q,/
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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42 i
But wo will talk about the ovaluation modal l
2 and a description of the code.
We will show you some 3
comparisons to the LST using the lumped parameter model 4
and talk about the implications of that, how that work has i
5 supported what we're doing in the evaluation model and get into a lot more detail on our approach using the lumped 6
7 parameter model.
8 There are two issues that I guess were 9
dominant'in the last meeting that we had with you back in 10 May of 1996.
That was a meeting on the whole testing
~
' program, containment testing part, being part of that.
11 12 And a lot of the discussion centered around the 13 circulation and stratification and how we can model that
, 14 and also the water coverage.
Really, those are the key 35 features of the AP600 that's different from operating 16 plants.
We want to spend some time focusing on those 17 issues and show you how we've handled those and end up la with the total model that-is a conservative prediction of 19 the pressure in the AP600.
20 We've already talked some about the key 21' documents.that we're using in support of the AP600.
The 22 PIRT report which has been_ mentioned already, we issued 23 the latest revision in June of this year.
The scaling 24 report was also issued in June of this year and the heat 25 and mass transfer report which talks'about the data that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISt.AND AVE., N W, (202) 2344431 WASHINGTON, D.C, 200064 701 (202) 2344433
i 43 1
wo uced to davolop our hoct cnd m2oc trcnofor corroletione 2
and '.that those correlations are.
i Y2 3
DR. CATTON:
That would have been helpful to 4
me.t.f I would have had that third document.
5 MR. GRESHAM:
Yes, it would have.
6 DR. CATTON:
Is there any reason we don't have 7
it?
8 MR. BOEHNERT:
No, I don't know.
9 DR. CATrON:
In some respects, you're going to 10 ask us to take some things on faith.
11 MR. GRESHAM:
Yes, if you haven't 12 DR. CATTON:
That hasn't worked in the past.
13 MR. GRESRAM:
It hasn't so far, no.
,-~
(,)
14 MR. ZUBER:
Well, or we can just make comments 15 based on these two documents and leave it at that and then 16 we can address your arguments in a month because I'm not I don't want to deal with religion on beliefs, we deal 17 18 with facts.
And we have two reports to review and at 19 least I shall comment on those two.
20 CRAIRMAN KRESS:
We need to get you these 21 other documents.
22 MR. ZUBER:
Well, the point is I have a foot 23 and a half of reports and I looked at those two which I 24 thought we~w pertinent for today.
,.m
(
)
25 MR. SCHROCK:
Documentation is always a NEAL R. GROSS CoVRT REPORTERS AND TRANSCRIBERS 1MO RHODE lSUND AW,, N W.
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44 1
probicm in that it'o alwayo bohind.
Like wa hcyo o Juno 2
date on this new set, but there are things that obviously n(V i
3 didn't have time to fix that the staff was quizzing you 4
about.
And so another version of the documents is doing 5
to have to be done in order to have a complete package in 6
the end.
Bu" ve're always confronted with reviewing your 7
documents tNit cr9 kind of six months or a year behind.
8 What you're saying is the status.
That makes it very 9
hard.
10 MR. ZUBER:
May I make a suggestion, Mr.
11 Chairman?
Instead of them going to argue what they have 12 in the document which we didn't go into it, analyze and 13 read it, they should really listen to our comments and g
(,)
14 then maybe delay the arguments, how good it is or how bad 15 it is and address our comments next time.
So at least I 16 don't have to trade on beliefs, not on facts.
17 CHAIRMAN KRESS:
It would be good if we could 18 get those comments written down in a coherent fashion to 19 get to Westinghouse.
20 MR. SCHROCK:
Coherence is the key.
21 CHAIRMAN KRESS:
Well, you guys talk awfully 22 fast and it was hard for me to follow and I'm sure they 23 didn't catch all of it either.
24 DR. CAlTON:
There's a transcript.
25 CHAIRMAN KRESS:
Well, the transcript may or NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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45 1
may not ba uceful for'that.
Tranccripto doa't somatimac 2
do the job on that.
I think a separate set of written 3
comments from you guys will be very useful.
4 DR. CATTON:
And then maybe they could address 5
the comments and they could do this and get something back 6
to us that's in writing before we have the meeting.
7 CIAIRMAN KRESS:
Which means we need to get 8
those comments down and to these guys in sufficient time 9
before the December meeting.
10 MR. ZUBER:
In fact, really, let's not really 11 waste our, use our time or waste our time discussing 12 religious beliefs.
Let's discuss what we have here.
You 13 can hear our comments, bad or poor, think about them and
. 14 then when you make the next-presentation, you have already 15 good answer and then_we can agree _with you or hopefully 16 agree with you and not disagree.
17 MR. GRESHAM:
Hopefully.
18 MR. ZUBER:
I wish we could.
I think it's 19 frustrating.
We are pit' ting ourselves over a period of 20 five years.
21 MR. GRESHAM:
We have done a lot, I think, to 22 address the comments that you've had and --
23 DR. CATTON:
But you still haven't divided 24 through by volume.
()
25 MR. GRESHAM:
We have not divided through by NEAL R. GROS 5 CoVRT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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46 1
voluma.
2 DR. CATTON:
Maybe today you're going to
,7 3
(
)
\\
/
3 explain to me why what you're doing is the correct thing.
4 MR. GRESHAM:
I believe in the presentation on 5
scaling you'll hear why we think that's okay.
6 The material we have prepared for today 7
focuses mostly on the PIRT and scaling.
There is some on 8
the heat mass transfer report in terms of validation of 9
the correlations.
Although you haven't seen that report, 10 I believe what we're presenting to you will be pretty 11 clear and you can go back and look at the report and 12 understand some more details.
13 The WGOTHIC validation report was issued in l'
l 14 July of 1995.
It had comparisons of WGOTHlc to LST as s-15 well as to other test facilities and talked about the 16 different models and code description.
17 The upgrade assessment which was issued last, 18 no, this month, earlier this month, addresses the changes 19 in the code that have occurred since 1995.
There have 20 been some updates to correct some errors that were found, 21 both by NEI who developed GOTHIC and us, and some 22 improvements that were made to the code.
So that report 23 addresses the changes and the impact of those changes 24 since that time.
()
()
25 DR. CATTON:
There was a memo from Brian NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHOCE ISLAND AVE., N W.
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47 1
McIntyre to TR Quay that listed thoso.
Is that what 2
you're referring-to?
I i,
i 3
It listed changes to GOTHIC that are -- they
}
4 were judged to be insignificant or negligible.
1 i
.5 MR. GRESHAM:
Was this the letter in 1995?
i l
-6 DR. CATTON:
It was 12 October 1995.
7 MR. GRESHAM:
Okay.
8 DR. CATTON:
Is there anywhere in-all of this 1
9 documentation that we can see the basis for that-_ judgment?
i i_
10 The reason I ask is there are some things like watts per i.
T 1
11 square meter to BTUs per hour foot squared and the_ change 1
l 12 in the' coefficient was a factor of three.
And then in 13 another one a drop in the interfacial drag, it changed by 14 a factor of 10.-
Those don't sound insignificant to me, 15 but somewhere I assume there's a basis for the statement.
16 MR. GRESHAM:
Yes, there is a basis for the 17 statement.
Let me just deal with one of them, the watts 18' per issue.
19 We do everything in English units so --
20-DR. CATTON:
I appreciate that.
21 MR. GRESHAM:- So as Larry Hochreiter, 22 Christian units, so we haven't encountered that..
23 There is nothing that I'm aware of, offhand
-24 that goes_through each of those things in any of these-25 documents.
There-is that kind of information that we have NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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48 1
dona.
2 DR. CATTON:
Change in interfacial drag by a 3
factor of 10 is not insignificant.
Now it may lead to 4
differences in the predictions that are small, but i
L 5
comewhere I think you need to say something about that.
6 MR. GRESHAM:
Yes, I think --
i 7
MR. THROM:
Dr. Catton, Ed Throm with the 8
staff.
I believe -- I'm trying to remember the time frame t
9 of your references, but I believe after Westinghouse got 10 our response to not wanting to make those changes, they 11 came in and made those changes.
L 12 I believe that as part of an EPRI review in 13 1993, or thereabouts, there was an identification of a 0
3 14 number of documentation problems in the code and coding 15 errors. ~ Westinghouse's first evaluation was some of those 16 things didn't impact their application of the code, but we 17 thought that was a bad practice and they did come in, I 18 think, in November with a commitment to make those changes 19 and basically upgrade their version of GOTHIC to 4.0 and l
l 20 it's the 4.0 documentation now that they're relying on for l
21.
understanding GOTHIC.
22 MR. GRESHAM:
Okay, thank you, Ed.
I missed
- 23 that nuance.
We did correct that.
Maybe we all would
[
j 24 have been better off.
25 WCAP-14407, Rev.
1, was issued in July of this NEAL R. GROSS COURT REPORTERS AND TRANSCR'BERS 1323 RHoDE ISLAND AVE. N.W.
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('02) 2344433
,,,-,,_.4 r__.,-,.--.------.-
c m m,_,,,, - -,,.., -.. - -..,. -, -. _,... _., ~,.,., _, _.. -,._,- -...4.
49 1
yccr and that 10 the two voluma cot that unfortunctoly you 2
haven't looked at yet, but it delves into a lot of details L_ /
3 about how we're applying the GOTHIC code to calculate the 4
pressure response for AP600.
Chapter 9 was mentioned as 5
dealing with the mixing and the stratification effects.
6 The details about how we're applying that in 7
WGOTHIC we will cover when we talk about the application 8
of WGOTHIC.
However, tomorrow, we will talk about the 9
data that we're using in support of that from tests.
You 10 mentioned a list of them this morning.
We are going to 11 touch on that tomorrow.
Hopefully, that will answer part 12 of your questions there, about how we're using that.
13 Finally, of course, the SSAR tells what the bottom line p
i
)
14 is.
15 I just wanted to take a few moments to give an 16 overview of how the AP600 design works.
I won't spend a 17 lot of time on that, but the reactor cooling system, of 18 course, is in here and there is an accumulator and core 19 makeup tank that provides injection and then the in-20 containment refueling water storage tank provides make up 21 to the reactor cooling system.
And then following the 22 LOCA, the system will flood in and cover the cold leg and 23 then that will provide cooling. The break occurs in this 24 compartment and then there's an annulus around the steam f')h 25 generator which releases the steam up into the upper part u.
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50 1
of tho-containmont end soto up the circulation pattern.
2 Cooling, of coursc, is provided on the shell.
-3 Water from the passive containment cooling water storage 4
tank up top is distributed on the containment shell and 5
that evaporates and there's -- the next drawing gives me a 6
little more room to point.
7 The containment is surrounded by a shield l
-8 building and there are inlets, I believe there are 16 9 - inlets around the circumference of the shield building up
-10 high and the air comes in and goes down, what we call the 11 down cover and then it goes up the annulus and that air 12 pulling past there helps to enhance the cooling.
13 The water from the water on the top goes down
()
, 14 and enters a distribution system on the top of the 15 containment.
There's a bucket at the top that goes up and 16 then the water spills over and it goes down to a system of 17 weirs and they're indicated here and here and that weir i
j 18 system distributes the water.
In the back of your hand 19-out package, there are some vu-graphs that we will not 20 present formally that deal with the different test 21 fac.lities and there's a picture of the weir cystem back 22 there.
23 We will get into a lot more details on that at 24 the meeting in December when we talk about the
()
25 application.
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-- U
~. _ _. _. _ _. _
51 1
MR. SCHROCK - Could yca davolop a tio batwacn 2
a diagram such a this and the calculation which is done by 3
GOTHIC and the lumped parameter mode?
It may solve some 4
of the_ questions that are in my mind about what's actually
{
5 done in that calculation.
As I envision this, you've got i
6 many different surfaces that have had different histories 7
and have different physics associated with them that tend 8
to give a nonuniform boundary, as I said earlier, on the 9
gaseous envelope.
10 I don't understand how that's dealt with in i
11 the lumped model.
If you settle on an isothermal
. 12 boundary, how do you choose it in relationship to the heat i
13 and mass transfer processes that occur at the interface.
14 A diagram that shows what are the components in that
(
f l
15 equation, okay, pressure rate of change equation, energy, 16 mass, crossing the system boundary, how they are dealt i
17 with in GOTHIC in a simple diagram would be very 18 beneficial and I don't understand why that isn't the first r
19 step in explaining what you're doing in this calculation.
[
20 I think it's essential.
I'm going to keep bringing it up
}
21 if I d'on't see it.
i 22-Do you understand what I'm asking for?
[
23 MR. GRESHAM:
I believe I do.
And I don't 24 you probably won't be satisfied completely at the end of i
25 this two-day meeting in your answer to that question 4
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHoDE ISt.AND AVE., N.W.
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-wr-r,--
+ -.,
,y
.-----.rwev-,-v=v**e--
e-.n-e----*-+w-~+--
--~,3<*-w+s--m-r-w
-,----a-
-+-e t-w e---
rv
--v=,we
-4
-+v--
- ~ ~-
-r--w w-m --
---e
52 1
baccuos we're not cponding a lot of tima, wall, we're not 2
spending time on talking about the GOTHIC code and the 3
specific model that we're using.
4 DR. CATTON:
Well, but see this goes further 5
than that.
It relates to what are your tests that support 6
what you're going to do.
7 MR. GRESHAM:
Right.
8 DR. CATTON:
If you~tell Virgil or you give 9
Virgil an answer to the question he raised, then he can 10 begin to think well,-this particular set of experiments 11 will give you the proper coefficients for that.- And he 12 begins to pit it together.
If you don't do that, then all 13 these discussions keep ~ coming up.
Somewhere you need Co 14 do it.
I'd like to see right here what you think where 15 does the steam come from at the bottom of that containment 16-volume and where is it on the floor that it's coming into 17 the upper volume and below that, how far away is the 18 break, what opportunity is there for air to mix into this 19 steam flow, where is ADS relative-to this and then once-20 you have this rising because you make an issue in the 21 report _about the analysis that was-done by Peterson.
I' 22 can't come to
.ips with what he did until I can see 23 what's going on here, because I have counter examples to c
24 what he has suggested.
25
- )ne of them is when they burned the sugar cane NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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53 i
fields in Hawaii and the plumso want up 5,000 feet.
2 That's just buoyancy driven.
You don't need momentum.
3 Just what are you doing and how are you doing?
Where does 4
the air go? _Certainly, air is trained and is carried to 5
the top.
The steam is condensed out.
Where does the air 6_
go?- Does it:come down the wall?
What assumptions have 7
you made?
Still, nothing about the code.
8 MR. ZUBER:
This is a good example because you 9
try-it and then you scale it.
You assume different heat 10 transfer modes and you can see how different assumptions 11 impart your nealing and yoil can d? ~ w to a conclusion, but 12 not having this and relying on the code in the documents 13 we didn't see, it's a religion.
14 MR. GRESHAM:
Okay.
We will cover some of 15 this tomorrow in the presentation.
-16 DR. CATTON:
I'm just trying to steer what we 17 hear in the next two days a little bit.
18 MR. GRESHAM:
Okay, I appreciate that.
19 MR. SCHROCKt I just want to make one more 20 comment about a flavor that I got from reading the scaling 21 report here and it-leads me to think there may be a 22 miscenceptica about what's going on when the' discharge 23 through ADS is still critical flow controlled.
What you have then-is a thermodynamic state at the point of choking 24 25-which is at a pressure much higher or higher than that'in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBEAS 1323 RHODE ISLAND AVE., N W.
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~
54 1
tha containm:nt.
2 And so what happens as that effluent goes into
\\s >
3 containment is that it comes into equilibrium whether 4
through a totally irreversible process, you know, you look 5
at things like the throttling into a condenser in a 6
refrigeration system, what do you do?
You say it's a 7
constant enthalpy process and you find what is the quality 8
of that mixture which ends up in equilibrium closely and 9
in the condenser.
10 I don't see that understanding of what's 11 happening in the discharge with -- critical discharge into 12 containment in determining this steam input quantity.
13 There seems to be some misconception there and I hope I'm p(,)
14 wrong about that, but as I read the words in this report, 15 it does appear that there is a misconception there and 16 that it may not be correctly evaluated.
17 I think a look at that and an explanation 18 during the meeting of how that steam source is evaluated 19 when there is critical discharge, that would be helpful.
20 MR. GRESHAM:
Okay.
21 DR. CATTON:
Even after critical discharge.
22 MR. SCHROCK:
Yes, even after, but especially 23 then.
24 MR. GRESRAM:
We will talk about that.
Just (Jg) 25 let me say a couple of things.
Hopefully, we're clear NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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55 1
thingo up.
Tho GOTHIC modal, wo hava, it'a lumpod 2
parameter, but we have nodes for each of the different (3
V 3
regions down below deck.
A break occurs here in the steam 4
generator compartment where the cold leg comes up to the 5
steam generator, that's the limiting LOCA case.
We also 6
looked at the hot leg break.
7 DR. CATTON:
So how does the steam get into 8
the upper part of the containment?
9 MR. GRESHAM:
The steam generator goes through 10 the operating deck here and then there's an annular flow 11 around that steam generatcr and goes up to the upper 12 containment.
And there are also paths coming from the 13 other compartments into here and it sets up circulatl m 73
()
14 that occurs.
15 DR. CATTON:
But it's air that's circulating 16 down through the compartments and across to mix with the 17 steam?
18 MR. GRESHAM:
There is an air steam mixture 19 that circulates through here.
E0 DR. CATTON:
When you do your lumped 21 parameter, it is an air steam mixture, that's correct.
22 MR. GRESHAM:
That's correct.
23 DR. CATTON:
It reality, it may no be.
It 24 could be pretty much air because you condense most of the lG) 25 steam out.
O' NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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56 1
MR. GRESHAM:
I ballovo wa'11 anow you that in 2
reality it'c a mixture as well, r~x
(
)
k/
3 You're right, there is some condensation --
1 4
DR. CATTON:
Well, not from LST or LTS or.
5 whatever it is.
Okay.
6 MR. GRESHAM:
And then the climb models, the 7
condensation on the inside and ovaporation on the outside B
and there are discrete nodes as you go up and there are 9
wet sections and dry sections depending on the water 10 coverage which factors into that.
11 That detail will be in December when we talk 12 about the application.
13 MR. SCHROCK:
Do I get the right view from n(,)
14 this report that the assumption is that you have a 5 mil.
15 thick film everywhere on the inside of the containment?
16 MR. GRESHAM:
If you take the flow race that's 17 applied and use that laminar correlation and calculate 18 what the average film thickness is, I believe it varies 19 from 5 mils. to 12 mils.
Is that correct?
It's not the 20 assumption.
It's actually wavy laminar flow and with the 21 model WGOTHIC that deals with that.
22 MR. SCHROCK:
I don't think you answered the 23 q'4e s t ion.
I read here that it's assumed that the film is 24 constant at 5 mils.
Is that the basis of the GOTHIC
,m
(
)
25 calculation for this lumped mode everywhere a 5 mil. film?
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57 1
MR. GRESHAM:
I'm going to rofor to Den 2
Spencer to answer that question.
)
x_J 3
MR. SPENCER:
Hi, this is Dan Spencer from 4
I'd like to try to explain that.
There's 5
actually two models or two things that we're talking I
6 about.
One is the scaling analysis which makes certain 7
assumptions to simplify the analysis so that it's more 8
amenable to simple solutions.
The other is the WGOTHIC 9
calculation in which the code is able to do a much more 10 complicated, more detailed analysis.
11 For the scaling analysis, we looked at the 12 film flow rate, condensed flow rate on the inside and the 13 evaporating flow rate on the outside and came up with an
(
)
14 effective heat transfer coefficient where we use the Chun 15
& Seban correlation which is the basis for our wavy 16
- .minar flow to determine what the heat transfer 17 coefficient was and having done that, one can also extract la an equivalent thickness from that although this equivalent 19 thickness really doesn't mean anything physical.
It's 20 actually a wavy flow.
Consequently, the thickness varies 21 from very thin to much thicker than thic effective 22 thickness.
23 MR. SCHROCK:
Well, Chun and Seban worked on 24 experimental data from vertical tubes and you have this
,3
(
)
25 dome which has much thicker films in relation.
It even v
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58 1
hno dropa coming off of it in plecco.
2 How do you apply Chun and Seban's correlation V
3 for vertical surfaces to the dome part of this 4
containment?
5 What is the relevance is a better way of 6
stating it.
What's the relevance of Chun and Seban to 7
mass transfer on the inside of this stone.
I don't see 8
any.
9 MR. GRESHAM:
Well, the Chun and Seban 10 correlation gives us a measure of the thermal resistance 11 of the heat transfer coefficient of the liquid film.
12 MR. SCHROCK:
On a vertical surface.
13 MR. GRESHAM:
That's right.
The Chun and (g) 14 Seban correlation was derived for a vertical surface.
We 15 have included in the -- we've expanded our data base in 16 applying the Chun and Seban correlation by including heat 17 transfer measurements from the Wisconsin tests which were 18 made on plates that varied in inclination from horizontal 19 to vertical, zero, 6 degrees, 12 degrees, 24, 25 degrees 20 and so on.
21 There are data that have been -- that we have 22 presented in the heat and mass transfer correlation report 23 that we believe supplement Chun and Seban data and help 24 support the claim that the correlation is valid for
()
25 inclined surfaces as well as vertical surfaces.
O NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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59 I
l 1
MR. SCHROCK:
I've soon your reference from 2
time-to time on this draft thesis, University of O
3 Wisconsin.
I don't understand that reference.
I've not l
4 seen the thesis.
-I presume it may have eventually been an l_
5 accepted thesis.
Has it been published in the paar review
\\
6 literature?
Is there something you can point-to that is 7
better than a reference to a draft thesis that can satisfy 8
me that what you're saying about the applicability of-Chun j
9-and Seban's correlation to these near horizontal surfaces i
10 makes any sense whatsoever.
I l
11 My experience with these things tells me it 12 should not and I don't understand how you've made it look i
i 13 like it does.
So 1 need to see that evidenco somehow.
14 And the reference you give me is not a retrievable 15 reference.
I don't know how to get it.
I don't want to 16 try.
17 MR. GRESHAM:
I believe that was published.
i 18 MR, SCHROCK:
Then why don't you tafer to the 19 published work?
20 MR. GRESHAM:
We need to check and update that 21 and confirm that, i
22 MR. SCHROCK:
What is the reference that shows 23 how you have demonstrated the chun and Seban for vertical-l 24 surfaces is applicable to these near horizontal surfaces 25 or these inclined surfaces?
4 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE,. N W.-
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!_._:_-_____;-u..u,-;__._,___,.__._._._,_.__
60 1
MR. SPENCER:
WCAP-14326 procanto the dnto, i
2 DR. CATTON:
14326, that's a new number, isn't (w
ss 3
it?
4 MR. SPENCER:
No, that's the heat and mass 5
transfer.
6 MR. GRESHAM:
That's the report you haven't 7
seen.
8 DR. CATTON:
That's the one you're going to 9
get us copies of, right?
10 MR. BOEHNERT:
Right.
11 DR. CATTON:
Soon?
12 MR. SCHROCK:
Okay, we'11 review it when we 13 get to that.
,-)
14 MR. ZUBER:
See, what you really have is 15 either a jet or a plume.
You have a stagnation point and 16 then the thing curves and it's quite a flaw in the 17 boundary layers on that ceometry.
It would be quite 18 different from the one referenced by Seban or achida.
And 19 I
don't have the Wisconsin data.
So it'a qdte a 20 different configuration and the flow in the boundary layer 21 develors condensation, then the circulation, it would be 22 very useful to have a set of experimental data for that 23 kind of geometry.
24 MR. GRESHAM:
Okay, you will see more data on (n) 25 that in upcoming presentations.
Nd NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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61 1
MR. ZUBER:
Let ma say you hr.ve the facility.
2 If-you do it correctly, you could obtain data on that.
3 It's too bad five years have gone and we still don't have 1
1 4
it.
1, 5
MR. GRESHAM:
This is just a sequence of 1
6 events for the water distribution.
It is initiated on a 1
7 high-pressure signal, and we assume 20 seconds for the 8
valve to open and then up to 30-seconds for the bucket to l
4 j
9 fill on the top of-the containment.
And then it begins to 10 spill over and spills to the second weir, which fills at i'
11 112.
And then that spills over, and the second weir fills 12 at 187.
And then based on observations in the water 13 distribution distribution test that we ran.
We observed 14 that.
Steady state coverage was to be developed at 337 l
15 seconds.
16 And those numbers are used in our evaluation 17 model.
We assume that the flow is there at 337 and 18 there's no flow up to that point.
So that's a small l
19 conservatism in the use of the water.
[
20 In addition, the --
21 DR. ZUBER:
But your experiments were run with 22 more water than we expect in AP600, 4-23 MR. GRESHAM:
No.
Just the opposite.
I'm t
24 talking about the water distribution test.
This was the 25 one-eighth sector test that was run for water NEAL R. GROSS COURT REPORTERS AND THANSCRIBERS 1323 RHODE ISLAND AVE., N W, (202) 2344 433 WASHINGTON, O C. 20006-3701 (202) 234 4433 i-_,
_., _ - ~. ~... _. _. _, _. - _. _ _. -. -. _ _.. _ -... _. _
r_-.~..__...,-
62 1
diotribution.
2 DR. ZUBER:
And you have less water in the v-3 test?
4 MR. GRESHAM:
The maximum flow rate for that 5
facility was 220 gpm, which is what our design was at the 6
time.
And we have subsequently increased the flow rate in 7
the initial part.
And I'll show you a curve in a minute 8
9 DR. ZUBER:
The reason I'm --
10 MR. GRESHAM:
to 440 gpm.
11 DR. ZUBERt Right.
I don't know how to 12 interpret your statement on Page 11-4.
This is external 13 water flow too high for some tests.
(,)
14 MR. GRESRAM:
That was on the large-scale 15 test, the water flow was too high for some tests.
This 16 table that I presented is based on the water distribution 17 test, which is the basis for when we establish coverage, 18 not for the basis -- well, there's more in the water 19 coverage story than the water stability.
It is also based 20 on large-scale test data.
21 MEMBER SEALE:
This is the one-eighth pie 22 section?
23 MR. GRESHAM:
That's correct.
And this was 24 out at the Waltz Mill facility.
I don't know if you had
,-(m 25 an opportunity to view that or not.
j v
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63 1
DR. ZUBER:
Wo etw thot.
Wo ocw it.
i 2
MR. GRESHAM:
Okay.
()
3 DR. SCHROCKi It has less vertical surface 4
relative to AP600; right?
l 5
MR. GRESHAM:
That's correct.
It has ten feet 6
of a side wall, I ')elieve.
7 Oh, I almost forgot the point I was going to 8
make here.
In the water storage tank, there are stand 9
pip,es that allow variation of the flow as the transient 10 progresses.
11 of course, at the beginning, you've got the 12 maximum flow.
And then as stand pipes uncover, there's a 13 reduction in the flow rate, which was depicted here.
It's V
14 on a long scale.
So it's kind of hard to get the full 15 impact of it.
16 (Slide.)
17 MR. GRESHAM:
This shews the flow rate from 18
- he bucket and then the flow rate from the second weir as 19 a function of time.
And it's about 440 gpm initially.
20 That slowly decreases until about two and a half hours.
21 The first stand pipe uncovers, and the flow late reduces 22 to about 110 gpm.
23 That flow rate continues until 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> into 24 the transient.
And then the next stand pipe uncovers, p
()
25 And I believt-it goes down to approximately 55 gpm.
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64 1
DR. SCHROCK:
Lat'e coo.
Wharo is that on tha 2
pounds per second scale?
l t 6
\\/
3 MR. GRESHAM:
This is the 2 and a half hours i
s 4
where it goes to 110 gpm, and this is the 30-hour drop.
5 I'm sorry.
No.
Yeah, that's right, 30-hour drop.
Then 6
it continues at that flow rate up until three days, at 7
which time the flow rate, if you uncovered the last stand 8
pipe, it would be the only one left, and it would drop 9
down.
10 However, there's an auxiliary tank for water 11 that would be pumped up there.
So the flow rate can be 12 maintained at this value for at least seven days and I 13 think beyond.
^
(T
/
/
14 DR. CATTON:
How are these flow rates chosen?
15 Chosen on the basis of decay heat or something?
16 MR GRESHAM:
yes.
17 DR. CATTON:
Does it match the decay heat or 18 exceed it or what?
19 MR. GRESHAM:
It exceeds it.
It's pretty 20 close to the decay heat curve.
In the initial part, 21 you've got to handle the blowdown and then all the other 22 energy sources.
Decay heat removal, basically.
23 DR. SCHROCK:
What limits that seven days?
24 Why can't it be maintained indefinitely if you're pumping 4
s
(
)
25 water up there?
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65 1
-MR. GRESHAM:
Actually, it can bo.
You can i
L 2
bring water in.
There's enough water for seven days, but l
l 3
by that time, you can haul water in from lots of places.
j 4
Did you want to say something else?
Oh, okay.
}
}
5 (Slide.)
+
i 6
MR. GRESHAM:
This compares a few parameters 7
for AP600 and the standard two-loop plant.
They're i
1 8
approximately equivalent in size.
The power for AP600, i
9 the core power, is a little higher.
The volume is also l
4 4
10 higher.
The power-to-volume ratio is lower for AP600 than 11 for the two-loop plant.
I r
12 In terms of heat removal, in heat sinks, the d
13 concrete mass inside containment is approximately the
}
, 14 same.
There is a lot more exposed steel inside the AP600 l
15 containment.
So it provides additional heat sink t
i 16 utilization because of the different construction f
i 17 techniques that are used in AP600.
l' 18 And then for long-term cooling, obviously it i
i 19 uses passive cooling; whereas, the two-loop design has 20 sprays and fan coolers that provide cooling.
21 DR. CATTON:
That internal heat capacity would l
22 be pretty much used up by the blowdown, wouldn't it?
It
]
23 helps you control the blowdown peak.
24 MR. GRESHAM:
It helps to mitigate the
()
25 blowdown peak.
Actually, there is still capability to NEAL R. GROSS 4
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--n.A-.n-.
...-n_-,.-,,n..n.,,,,,,,.-n
-..n..,,n_-,
,,~-,,,,,,,.,,--_nn,,-
66 1
ebcorb heat efter blowdown 1o over in the stool.
By ths 2
time you reach the_second peak, certainly you're not 3
getting much utilization out of the absorption by steel.
]
]
4 The concrete takes longer to heat up and is a much slower 5
process.
l 6
DR. CATTON:
So in your analysis during the 7
pressure decay, do you include the energy that's available
)
j 8
in the steel?
)
i 9
MR. GRESRAM:
Yes, that is released back.
10 DR. SCHROCK:
Well, you have different 11 transient conduction problems for the steel and the 12 concrete.
And they result in different surface if 13 temperatures for those structures in the nuclear world.
l 14 MR GRESHAM:
Yes.
15 DR. SCHROCK:
Is that smeared out in this 1-l 16 lumped capacity analysis?
That's part of what's bothering 17
)
18 MR. GRESRAM:
Okay.
I meant to mention that 1
19 when we were on it before, and we got off on another
{
20 topic.
Within the different nodes, in the lumped 21 parameter formulation, we have nodes for the different 22 regions below deck.
And then there's some breakdown above 23 the deck as well.
24 The heat sinks associated with those volumes
()
25 are matched up appropriately.
There are basically three NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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__---.--w-3-,mrw-
- v, e < v vr^ =-e e w---r w mem m,1--<,,.-,~.,we-
-.-wwme--vpwe-=---
.---r----
-ww----
m sw=-
er---,---g--yw-y-y-'t
67 1
difforent typas.
Tharo'o just concroto.
Thero'c 2
steel-lined concrete.
And there is just the steel.
And 7-('
3 it does model the temperature of those heat sinks, as it 4
should.
5 Another feature -- and this is jumping --
6 DR. SCHROCK:
Does that lead to different 7
condensate interface temperatures for different nodes?
8 MR. GRESHAM:
Yes, I believe it does.
9 DR. SCHROCK:
You're not sure?
10 MR. GRESHAM:
No, I'm not sure.
I think 11 somebody who is going to be talking to you later knows 12 more about it than I do.
13 DR. SCHROCK:
I'm looking for the answer to
/~N i
L/
14 that.
15 MR. GRESRAM:
Yes.
We'll try to do that.
I'm i
16 not as wel' -versed in this as some of the other guys.
17 Oh, another point I uas going to make, that in 18 the mixing and circulation and stratification assessment 19 within Chapter 9, we look at the impact of different 20 gradients on the utilization of the heat sink.
So we have 21 looked at that effect as well.
And you'll be seeing that 22 later.
23 The next three slides that I have in the 24 package deal with the regulations.
And since Ed already
!.,)
25 covered that, I'm just going to skip those except to say NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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68 1
that wa have factored those into our_ problem.
I balievo 2
that we' re demonstrating 'that' we meet ' noa regulations in 3
those different design criteria.
4 (Slide.)
5 MR. GRESHAM:
Real quickly, the design 6
pressure is 45 psi.
Wa do look at a minimum pressure-7 situation and also look et the pressurization of the 8
subcompartments.
And there's nothing different in that 9
methodology than what we've been doing for the last 25 10
- years, 11
-The temperature used for equipment 12 qualification is based on the maximum temperature that we
- 13 observe in the GOTHIC calculation. -That is consistent
)
14 with standard methods.
In fact, it's a little more 15 c'onservative because with the finer breakdown in the-
-16 noding, we have regions of higher' temperature than current-
-17 methods of smeared _ temperature over the whole, whole 18 thing.
19 (Slide.)
20 MR. GRESHAM:
And chen just one more thing on 21-10 CFR 50 Part 5247.
We believe that we have addressed 22 the features of the performance of this-in calculating the 23 heat pressure. -And we-do use a combination-of test data 24 and analysis and experience.
And as we~go through the
()
2r presentations, we intend to show you that we've covered NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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(
69 1
all of the important aspects and we've done it 2
appropriately.
,-~s 3
That ends my part of the presentation.
We're 4
almost to the end of the introduction.
Dan Spencer is 5
going to talk about the overall process, give you a little 6
road map to the presentations that aie coming up.
And he 7
will also talk about the format of tl.e road map or this 8
table that was provided to you.
9 As we go through the presentationa in the next 10 two days, we'll fill in the understanding of that table.
31 And then at the end of the meeting in December, we'll ha'e 12 covered everything and shown how it all fits together.
13 Any questions before I sit down?
\\_)
14 DR. BOEHNERT:
Yes.
Jim, when is Dan going to 15 go into a closed session?
Would it be when he talks about 16 the table?
17 MR. GRESHAM:
He's got this -- yes, it is when 18 he talks about the table.
19 DR. BOEHNERT:
Okay.
20 MR. GRESHAM:
He's got one slide on the 21 process.
This might be a good time to do it.
I don't 22 know --
23 CHAIRMAN KRESS:
I thought just before we went 24 into the closed session, we'd take a break.
(
)
25 MR. GRESHAM:
Okay.
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70 1
CHAIRMAN KRESS:
If you could let rae know when l
2 you're getting ready to do that?
,s
(
)
3 MR. GRESHAM:
Why don't you present the 4
process and then --
I 5
(Slide.)
6 MR. SPENCER:
I'm going to talk about the test 7
and analysis process.
This is a diagram which represents 8
the overall organization.
The diagram shows the major 9
elements in this process and how they're connected in 10 general.
11 The process elements, each of these blocks 12 represents a process element.
Each of these will be 13 covered in the four days of meetings we have scheduled
,n S-14 between today, tomorrow, and December.
w 15 The work on all of these elements is 16 completed, at least to the extent that we're going to 17 present it.
And it's documented i?. references that are la indicated in each block as well as the presentations.
As 19 we go through our presentations, we'll be providing more 20 specific references, too.
21 Starting off with the PIRT, the purpose of the 22 PIRT was to identify and rank phenomena.
That's followed 23 by our phenomena scaling.
We also refer to this sometimes 24 as phenomena assessment or horizontal scaling.
And by
/
\\
(,)
25 horizontal scaling, what we mean is where we take the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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71 1
conservation equations or the rate equations for mass 73 2
energy and pressure and we do or we look at a horizontal t
4 3
relationship between the terms in that equation.
4 We use that process to validate the PIRT, to 5
identify the important dimensionless gre :ps.
These are 6
groups like Reynolds number, the Prandtl number, Schmidt 7
number, and so on, to identify the important dimensionless 8
groups for the phenomena that we're evaluating and also to 9
identify, independently of the computer code now, to 10 identify the range of AP600 parameters, the range that we 11 need to validate these correlations.
12 out of this phenomena scaling or after this 13 phenomena scaling, then we get into evaluating the
(
)
'~'
14 distortions, into scaling the tests, both the separate 15 effects tests and the integral effects tests.
16 Out of the separate effects tests, then, we 17 identify models and correlations that we, the dominant 18 models and correlations that we, will specifically address 19 either by way of some kind of conservative bounding 20 evaluation or by way of a specific model, as, for example, 21 our condensation evaporation mass transfer models.
22 The specific correlations that we have 23 identified are condensation, evaporation, the above-deck 24 stratification, water coverage, the PCS air flow
,m I
\\
(,/
25 resistance, and circulation.
That's circulation both NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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i 72 1
within volumes and between the above/below-deck region of l
2 the AP600 contalement.
We have identified in that block, J 7-s
\\
)
3 too, the tests that support each of those phenomena.
4 Then out of the integral tests, we have scaled 5
the integral tests.
We came to some conclusions ou*. of 6
scaling that test.
I think the most important conclusion 7
of that is that the large-scale integral test is not a 8
valid code dP/dT representation but that the integral test 9
does have other usefu. information that we do use 10 elsewhere.
And we'll talk about that later on as we go 11 through those specifically.
12 DR. ZUBER:
For example, you use LST for 13 condensation.
x/
14 MR. SPENCER:
That's right.
15 DR. ZUBER:
But this would be just affected 16 the way Ivan discussed it.
So, really, when you make a 17 presentation to justify, you have to address the effect of s
18 distortion on that condensation process and in what time 19 window you are going to use LST for whatever you want to 20 use it for.
21 MR. SPENCER:
Okay.
We have part of the 22 presentation.
I don't know exactly when it's coming up.
23 But it more specifically addresses that.
And I think that 24 would be a good time to bring up this question.
/N
(_,/
25 DR. ZUBER:
And there is another thing.
I NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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73 1
mean, your break flow, how did you scale this?
Becauso 2
that will also affect the circulation in the container.
.s
~
3 So the question is:
It doesn't even appear here on your 4
little box?
5 MR. SPENCER:
Well, yes.
This is a very 6
high-level process diagram.
7 DR. ZUBER:
That's a high level.
That means 8
you have only two sources of energy.
What you're putting 9
in, that's your break flow and entropy and what you're 10 taking by condensation and heat transfer.
There are only 11 two.
And you cannot address one without the other.
12 The way I understand it, you really mixed them 13 in the way that you really cannot really differentiate,
'_)
14 but that's a source of energy.
And it has to be scaled if
~
15 you want to interpret circulation inside and 16 concentrations.
And the heat transfer process is a 17 condensation.
18 MR. SPENCER:
Those are certainly legitimate 19 concerns.
And we do talk about these later on.
- Again, 20 this is just a very high-level process diagram.
21 DR. ZUBER:
Let me say again energy input 22 through the break is a high process.
That's where the 23 energy comes from.
If we didn't have that energy, we 24 wouldn't have any problem.
~\\
)
25 MR. SPENCER:
That's right.
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74 1
DR. ZUBER:
And it doesn't even appear there.
2 MR. SPENCER:
I'm not trying to identify here fy
(
)
3 all of the important things.
We do that in other 4
documents in other places in other parts of --
5 DR. ZUBER:
You do agree that the energy input 6
sa important?
7 MR. SPENCER:
Yes.
8 DR. ZUBER:
If yes, why didn't you show it?
9 MR. SPENCER:
Because that was not the purpose 10 of this presentation.
11 MR. WOODCOCK:
Excuse me.
May I try to offer 12 a couple of comments?
This is Joel Woodcock.
13 What we're talking about here is the s-14 correlations that we've used in terms of the source of 15 mass energy in for the plant evaluation model.
Stop me if 16 you don't think this helps.
But for the evaluation model, 17 we' re using conservatively high methodology, gets the 18 energy out as fast as possible.
19 DR. CATTON:
What is conservatively high 20 methodology?
21 MR. WOODCOCK:
For the mass energy release, 22 the energy that's available, we get it out as soon as 23 possible.
24 DR. CATTON:
So you mean values?
.r
! s)/
25 MR. WOODCOCK:
Yes, actual values.
That's not x
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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75 1
a correlation, What we use is local data in the LST.
And f w)
I guess I'd like to speak very briefly to something you 2
!N
/
3 mentioned, Dr. Catton.
And I don't know how much we were 4
going La cover today because we had thought we had covered 5
it at the last meeting.
6 There are some slides at the end of the 7
package that you have that look at the large-scale test.
8 And it does, I believe, in there indicate where we took 9
non-condensible measurements.
And we did have several 10 places where we took non-condensible measurements.
11 So in our minds, what we're trying to do here 12 with the cuadensation correlation is to come up with:
13 Given a boundary condition that you know, what is the mass p_
\\
\\/
14 transfer rate to the wall?
And I think that was mentioned 15
- earlier, 16 Separately, then, what we do --
17 DR. CATTON:
Jast let me interrupt.
18 MR. WOODCOCK:
Sure.
19 DR. CATTON:
My recollection is that you did 20 make a couple of these measurements, but they were in 21 inappropriate places.
I would like to hear a separate 22 discussion of this when you try to argue about 23 stratification.
See, I don't buy the explanation you're 24 giving at this moment.
(,)
25 MR. WOODCOCK:
Okay.
Okay.
To speak to that, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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}
76 1
tomorrow I will be showing the NUPEC BMC CVTR data.
I'll 2
be talking about it.
The data is in Appendix 9C.
That's 7.3 i
)
~
3 one source of information for stratificatien, and there 4
are several scales.
And some of them are very large 5
scales.
We al so use some LST data there.
6 DR. CATTON:
But you use in your report 7
arguments about momentum, and you even have velocities.
8 And you refer to Peterson.
That means break flow is 9
important if you're going to make arguments about the 10 mixing.
11 MR. WOODCOCK:
That's correct.
12 DR. CATTON:
That's what Novak is pointing to.
13 MR. WOODCOCK:
Okay.
f' x-14 DR. CATTON:
In the document, you use those 15 things in order to make the documents.
Yet, it's not 16 here.
Somewhere you have to have a model for these 17 things.
18 If it's fully mixed, that is of singular 19 importance.
It's number one because it's the basis for 20 everything that you're doing.
If you don't want to 21 include it, I don't understand.
22 MR. WOODCOCK:
Well, in our minds, certainly 23 we're not trying to mislead anyone on this.
But in our 24 minds, the --
r~'
( )N 25 DR. CATTON:
In the spirit of completeness, --
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77 1
MR. WOODCOCK:
Yes.
2 DR. CATTON:
-- it should be there.
7~s
)
3 DR. ZUBER:
Let me say --
4 MR. WOODCOCK:
Wait a minute.
What we put on 5
this slide was the correlations under circulation, we have 6
to consider momentum.
We have to consider the effects of 7
break source density momentum, its buoyancy.
That's 8
handled under the evaluation for circulation.
That's why 9
you don't see it on this chart.
Simple, simple as that.
10 And so when I talk tomorrow about circulation 11 and stratification effectc, I'll mention something about 12 the effects of momentum on those parameters as a parameter 13 in circulation.
That is the only reason why it doesn't
)
14 appear on this chart, not that we're saying it's not
-ss 15 important, but, rather, it's a parameter which influences 16 these important phenomena and transport processes up here.
17 DR. ZUBER:
See, the way I came into it, you 18 want to use validated models for condensation in LST.
You 19 cannot separate this condensation process.
You want to 20 use it from that mixing and stratification.
It's --
21 MR. WOODCOCK:
Well, sir, I believe I can 22 consider it separately in this way.
And this is what 23 we're trying to say, that if I say I know a boundary 24 condition and I want to calculate the mass transfer to the
/~'T t
)
25 wall, I can use separate effects tests to get a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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78 1
correlation.
And something I'll talk a little bit about 2
tomorrow is then I can take a bias on that correlation and
,7-i 3
make that particular part of this calculation 4
conservative.
5 Then separate from that, the evaluation that 6
we've done is:
How can I get a conservative or a boundary 7
condition to use in this correlation?
And, in fact, it's 8
related to the use of sinks and conservatively
?
underestimating the value of sinks.
That's the way we've 10 separated it out in terms of our documentation.
So 11 hopefully that's not too confusing.
12 DR. SCHROCK:
When you talk about boundary 13 condition, what boundary are you referring to:
the (3
x~ l 14 condensate interface or the heat transfer surface?
15 MR. WOODCOCK:
Basically I boil that down into 16 the maximizing a non-condensible content and, thus, 17 minimizing the mass transfer rate.
18 DR. SCHROCK:
Wait, wait, wait, wait.
The 19 question is very simple.
The question is you talk about a 20 boundary condition.
A boundary is some surface that you 21 focus your attention on.
And you say something about the 22 state of the important variables at that surface.
What 23 I'm asking you is to tell me what surface you refer to 24 when you talk about boundary conditions in this context.
A
!.v) 25 MR. WOODCOCK:
Yes, sir.
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79 1
DR. SCHROCK:
Are you talking abott the 2
condensate interface with the gaseous medium or are you
,S t
t
'~'
3 talking about the heat transfer surface?
Just answer that 4
simple question.
5 MR. WOOCCOCK:
Okay.
There are two boundary 6
conditions.
There's the surface.
And then the one I'm 7
talking about, though, is the bulk condition near the 8
wall.
That's the boundary condition I'm talking about.
9 DR. SCHROCK:
The bulk condition near the 10 wall?
11 MR. WOODCOCK:
That's right.
In other words, 12 the steam concentration some distance away from the wall, 13 which is driving the mass transfer to the wall --
O i/
14 DR. SCHROCK:
You refer to the fluid 15 conditions in a transfer process as the boundary 16 condition?
17 MR. WOODCOCK:
That was the terminology I was 18 using.
Perhaps what I should have said was --
19 DR. SCHROCK:
No wonder we get so confused.
20 That's not a boundary condition.
21 DR. ZUBER:
That's a field.
22 DR. SCHROCK:
That's the field variable.
23 MR. WOODCOCK:
Okay.
That's good.
I like 24 that.
So what we're talking about when we do our
,/ 3
)
25 circulation evaluation is determining the field as it's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE, N W.
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80 1
adjacent to the various mass transfer boundaries.
And we I
f~s 2
want to do that in a conservative fashion.
- (
)
3 DR. SCHROCK:
Okay.
You need to do that 4
correctly.
You also need to do boundary conditions l
f 5
correctly.
And I hope we'll hear today or tomorrow about 6
the boundary conditions, what fundamental assumptions are 7
in that.
8 I commented in the opening remarks about the 9
list of assumptions that you have in the scaling report 10 that do not include anything about phase equilibrium at 11 the condensate interface, which is a usual assumption.
I 12 want to see what you do at that condensate interface.
13 MR. WOODCOCK:
Yes, sir.
I believe we'll r~s i
k/
14 cover that.
In the scaling evaluation, we'll talk about s
15 the surface; in fact, the liquid film interface 16 temperature and the assumptions that are made there.
17 DR. SCHROCK:
Okay.
18 DR. ZUBER:
Not to appear always critical, I 19 think this is a nice figure.
It gives an overview, I 20 think.
My compliment, it'e a nice figure.
21 MR. SPENCER:
Thank you.
22 DR. ZUBER:
So I'm trying to be positive also.
23 MR. SPENCER:
I appreciate that.
24 This is a top-level organizational document or (m) 25 presentation.
It's not meant to be comprehensive and r
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE.. N W.
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81 1
all-encompassing, to give you an idea of how our major 2
documents and our major work elements fit togetner.
(
)
'~'
3 Out of these two, then, comes the result of 4
conservative strategies or models.
And what we mean by 5
this is either we have treated such things as 6
condensation, evaporation, circulation, stratification, 7
either we have an equation with multipliers that make that 8
conservative or we have a conservative approach to that.
9 One of the obvious examples is the 10 stratification within volumes.
A lumped volume approach 11 cannot handle stratification within the volumes.
You have 12 to do something external to that to make sure that what 13 the code ends up doing really is conservative.
Oh m/
14 And in the 14th 407 Section 9 documentation, 15 we have devoted a lot of pages and energy and work to show 16 that there are conservative ways of or there are ways of 17 making the evaluation model conservative with respect to 18 stratification.
So that's what we mean by " Develop 19 conservative strategies and models."
20 Some of them are models.
Some of them are 21 things that we can do to the evaluation model by way of 22 biasing inputs or other things to make sure that the code 23 handles these phenomena in a conservative way.
24 CHAIRMAN KRESS:
Now, what my understanding
,m
(
)
25 is, what you did there was reduce the heat sinks.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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82 1
MR. SPENCER:
That was one of the things, yes.
2 CHAIRMAN KRESS:
I would be interested in s
/
T
\\)
3 having a quantitative feel for how much that offsets any 4
over-prediction of condensation on the rest of the 5
surface.
You know, if it's conservative, we have to know 6
how much the over-prediction was and whether this 7
compensates for it.
And that was a question that I had in 8
reading through this.
So I just flagged another question 9
I'm going to have.
10 MR. SPENCER:
Okay.
We'll have to defer that 11 until later discussions.
I'm not sure whether that 12 specifically is covered in these two days or not, 13 Then the other major flow path here, then, has A
i
(/
14 to do with the computer code, the first part of which 4.s 15 to select the computer code, which we all know was the 20 GOTHIC code, then to get to the second block, where we 17 identified code biases and capabilities.
That's based on 18 consideration of the models that the code, the GOTHIC 19 code, had in it, the code features, and test predictions.
20 By running the modei as we had it, comparing 21 it to the existing test data, then, we could look at it 22 and see what it was doing right and what it was not doing 23 right.
And that gave us some insight into what needed to 24 be fixed, what needed to be repaired, and gave us some
,m(,)
25 insight into what we needed up here, too, with respect to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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83 1
these conservative models and strategies.
2 Then we fed these in, along with the insight 7 ~s) 3 that we gained here, to apply these biases to the models 4
and inputs to come up with a conservative evaluation 5
model.
And out of that conservative evaluation model, 6
then, we predict the plant performance, which specifically 7
is pressure.
8 And, again, given these conservative models, 9
given the fact that not all of these phenomena are modeled 10 specifically, many of them have to be bounded because 11 they'ra simply so complicated within the context or 12 limita', ions of lumped parameter code, we end up doing some 13 conse.vative things in lieu of specific phenomenological I
T
's' 14 models.
15 The result, though, is this conservatively 16 evaluated source, conservatively evaluated volume, and 17 conservative heat sink, a fact that leads to the 18 conservative pressure prediction.
19 DR. ZUBER:
How do you evaluate conservatively 20 a volume?
21 MR. SPENCER:
A volume basically comes from 22 the drawing, from the design specifications.
We know what 23 the volume is.
We just make sure that we take the lower 24 side of the tolerances that --
/^
(,\\)
25 DR. ZUBER:
How big are those?
When I read NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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\\
84 1
that document, when you were talking about tolerances, I 2
thought you were chasing a moth and missing an elephant.
,S N]
3 CHAIRMAN KRESS:
That was my reaction to that.
4 DR. ZUBER:
Tolerance, how big that tolerance 5
should be in order to have an effect.
And I have so many 6
other distortions, which are really dominant.
And you are 7
telling me I'm taking into account tolerances.
It's --
8 MR. SPENCER:
I'm not saying that volume is 9
the things that makes or breaks this.
10 DR. ZUBER:
But you made a statement.
You are 11 using your conservative volume within tolerances.
As I 12 said, it's a moth compared to an elephant.
13 MR. SPENCER:
I guess I missed the point
/
N
\\~ ')
14 there, Dr. Zuber.
We've --
15 CHAIRMAN KRESS:
How much could your volume 16 vary --
17 DR. ZUBER:
How much can it vary?
compared to the total 18 CHAIRMAN KRESS:
19 volume?
It's not very much.
20 MR. SPENCER:
Not very much.
21 CHAIRMAN KRESS:
And that's --
22 DR. ZUBER:
That's my point.
23 CHAIRMAN KRESS:
That's his point.
24 MR. SPENCER:
And my point is simply that g3()
25 that's not a big deal.
We are just using a conservative NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISt.AND AVE., N.W.
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85 1
2 DR. ZUBER:
Then don't consider it.
Then
,s L) 3 address -- you know, you make a big point that you address 4
-- you had three comments.
One is the sink.
One is the 5
volume --
6 MR. SPENCER:
Right.
7 DR. ZUBER:
-- and then within the tolerances.
8 That's an epsilon.
9 MR. SPENCER:
Well, I couldn't tell you that 10 we're just doing volume.
I have to tell you it's 11 conservative, don't I?
12 DR. CATTON:
Yes.
13 MR. SPENCER:
It's not an arguing point, sir, f)
\\s) 14 DR. CATTON:
So if I read Section 4.4 of 15 14812, Rev.
1, it will tell me the basis for the value you 16 select for the condensation and heat transfer 17 coefficients?
18 MR. SPENCER:
It will tell you the basis for 19 that.
20 DR. CATTON:
So I'll know that you took such 21 and such a measurement and reduced it by 20 percent and 22 the basis for whatever it was you selected?
23 MR. SPENCER:
I'm not sure that it will tell t
24 you exactly such and such a measurement, but it will tell i
rN 25 you in general what we did, and it will point you to the v) i NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE.. N W.
(202) 234 4433 WASHINGTON, D C. 20005 3701 (202) 234-4433
i 86 1
documents that give you the specifics of exactly what ws 2
did.
And then it will tell you that it was reduced by so
,, \\
1
- d
\\
3 much.
4 DR. CATTON:
Could you get me the document 5
that has the specifics in it?
6 MR. SPENCER:
Those documents are all 7
referenced in Section 4.4 and --
8 DR. CATTON:
Unpublished.
9 MR. SPENCER:
No, sir.
All of these documents 10 have been submitted to the staff.
11 DR. CATTON:
Okay.
12 MR. SPENCER:
Westinghouse has submitted those 13 to the staff.
They're in their hands.
,,~
4 t) 14 DR. CATTON:
Okay.
15 MR. SPENCER:
That's the end of this part of 16 the presentation.
The next part I believe is closed.
17 CHAIRMAN KRESS:
Okay.
At this point, then, 18 I'm going to declare a break for 15 minutes.
Be back at 19 about 10 till 11:00.
And at that time, the meeting will 20 be closed.
21 (Whereupon, the foregoing matter went off the 22 record at 10:40 a.m. and went back on the 23 record at 10:58 a.m.
in a Closed Session.)
24
!v) 25 NEAL R. GROS $
COURT REPORTERS AND TRANSCR!BERS 1323 RHODE ISLAND AVE., N W.
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O CERTIFICATE.
This is to certify that the attached proceedings before the United States Nuclear Regulatory Ccamission in the matter of:
Name of Proceeding: ACRS - THERMAL HYDRAULIC SUBCOMITTEE Docket Number: N/A Place of Proceeding: ROCKVILLE, MARYLAND were held as herein appears, and that this is the original j
transcript thereof for the file of the United States Nuclear Regulatory Commission taken by me and, thereafter reduced to typewriting by me or under the direction of the court reporting company, and that the transcript is a true and accurate re' cord of the foregoing proceedings.
1A.
bORBETT'RINEA D4 official Reporter Neal R. Gross and Co.,
Inc.
O
'NEAL R. GROSS COURT REPORTERS AND TRANSCRIDERS 1323 RilODE ISLAND AVENUE, NW (202)234 4433 WASilINGTON,DC 2000$
(202) 234-4433
INTRODUCTORY STATEMENT'BY THE CHAIRMAN OF THE THERMAL HYDRAULIC PHENOMENA SUBCOMMITTEE 11545 ROCKVILLE PIKE, ROOM T-2B3 RCCKVILLE, MARYLAND SEPTEMBER 29-30, 1997 The meeting will now come to order.
This is a meeting of the ACRS Subcommittee on Thermal Hydraulic Phenomena.
I am Thomas Kress, Chairman of the Subcommittee.
The ACRS Members in attendance are Mario Fontana, Dana Powers, and Robert - Seale.
ACRS Consultants in attendance are Ivan Catton, Virgil Schrock, and Novak Zuber.
The purpose-of this meeting is for the subcommittee to continue' its review of the results of the Westinghouse test and' analysis Program -
-being conducted in support of the AP600 design certification.
During this meeting, the subcommittee will review key elements of the Westinghouse Passive Containment System test and analysis program. The subcommittee will gather information, analyze relevant issues and facts, and formulate proposed positions and actions as appropriate, for deliberation by the full Committee.
Paul Boehnert is the Cognizant ACRS Staff Engineer for this meeting.
Specific sessions held during this meeting will be closed to the public to discuss Westinghouse proprietary information as so noted on the Agenda.
A transcript of the meeting is being kept.
It is requested that the speakers first identify themselves and speak with sufficient clarity and volume so that they can be readily heard.
We have received no written comments or requests for time to make oral statements from members of the public.
(Chairman's Comments-if any)
We will proceed with the meet 3 ng and I ca)) upon Mr. Carl Berlinger of the Of fice of Nuclear Reactor Regule ton to begin.
O
i Advisory Committee on Reactor Safeguards 1
Thermal-Hydraulic Phenomena Subcommittee September 29,1997 AP600
~
Passive Containment Cooling System (PCS)
Edward D. Throm j
Containment Systems and Severe Accident Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation 415-3153 09-29-97 Siede 1 i
I AP600 PCS Containment Peak Pressure Analysis e 10 CFR 52.47(b)(2)(i)(A)
- Analysis, appropriate test program, experience, or combination
- the acceptability of the AP600 testing program
- the quality of the AP600 analysis codes
- the acceptability of the analysis codes for evaluating the design e General Design Criteria 16, 50, and 38
- (GDC 16)
Peak pressure less than design pressure (AP600 - 45 psig)
- (GDC 38)
Remove heat and rapidly reduce pressure
- (GDC 50)
Design base leakage following LOCA Conservatism in model and input
- Standard Review Plan Guidance
- 6.2.1.1. A PWR Dry Containment
- Assumptions to maximize calculated pressure and temperature
- Pressure after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> less than 1/2 of peak pressure
- 6.2.1.3 M&Es for Postulated LOCAs
- 6.2.1.4 M&Es for Postulated Secondary System Pipe Ruptures 09-29-97 Shde 2 O
O O..
.i 1
AP600 PCS Accident Specification and Phenomena Evaluation Phenomena identification and ranking
- Testing (separate effects and integral tests)
- Scaling
- Sensitivity studies
- Expert review Implementation in licensing evaluation model
- Test experience
- Modeling guidance
- Sensitivity studies i
i
- Evaluation and treatment of uncertainties and distortions j
l i
09-29-97 Slide 3 l
1
AP600 PCS l
Large-Scale Test (LST) Facility Scaling Evaluation e Objectives
- Support bounding ' conservative) evaluation model
- Identify approrriate constitutive relations and models
. Non-dimenisional variables
. Range of variables for operating and upset conditions
. Separate effects test
. Applicability of models and test databases
- LST as used to validate elements of bounding model e Scaling Approach
- To support the bounding (conservative) evaluation model
- Based on dominant phenomena and sufficient separate effects tests
- Evaluate system-level distortions in LST to examine WGOTHIC biases
- Bottom-up component-level scaling Staff believes LST is useful for bottom-up evaluation
~
- Top-down system-level scaling Staff believes LST has deficiencies for top-down evaluation 09-29-97 O
h h-
O O
O WESTINGHOUSE PROPRIETARY i
I l
ACRS THERMAL-HYDRAULIC PHENOMENA SUBCOMMITTEE MEETING WESTINGHOUSE AP600 PASSIVE CONTAINMENT SYSTEM TAP Rockville, MD September 29-30,1997
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AP600 Containment Evaluation Model inputs.
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Day 2 Agenda
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Introduction 3
l 4
DBA Pressure Evaluation Model Approach Evaluation Model Requirements i
Features Handled within WGOTHIC Code i
i Features Handled outside of WGOTHIC Code Validation Process t
l Circulation / Stratification Database Industry Experience Known Limitations l
How Limitations are Addressed l
1 Validation of AP600 Correlations AGRS 9Fa7 4
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Topics for December Meeting f,
AP600 Containment Pressure DBA Evaluation Model i
l Description of WGOTHIC Code Lumped Parameter Formulation i
Equations j
Numerics WGOTHIC Lumped Parameter Comparisons to LST WGOTHIC AP600 Lumped Parameter Model Approach Validation of Correlations Outside WGOTHIC Circulation and Stratification l.
Water Coverage / Stability l
l Conservative Model for Calculation Peak Pressure i
1 1
ACRS 9st 5
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I u.8 PCS Licensing Documents l
I i
PIRT WCAP-14812, Rev 1, June 1997 Scaling WCAP-14845, Rev 2, June 1997 Heat & Mass Transfer WCAP-14326, Rev 1, May 1997 WGOTHIC Validation WCAP-14382, Rev G, July 1995 WGOTHIC Upgrade Assessment WCAP-14967, Rev 0, Sept.1997 t
WGOTHIC Application WCAP-14407, Rev 1, July 1997 AP600 SSAR j
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W Irests = 1200 E' a - " - '" #
re-
,sr A senser acousse = 412 t' 3
ODI W *esef l
tw 4
ens y,7 l
i
Fi:ii i
PCS water supply and timing e
t Sequence of Events as PCS Cooling Film Develops Time Event (sec.)
Break triggers containment 0
t pressure setpoint Valve oaens 20 (solenoid-actuated, air-operated)
Pipe and bucket fill 37 First weir fills 112 Second weir fills 187 Steady coverage established 337 ACRS 95f7 9
o
.- O o
~
't 1
I i
iu PCS Delivered Flow vs. Time I
I i
80 64 r--
~
l 8
i G
I i
- 48 Bucket ---
I N
l 9
I 5
IMN 32 b
l
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~
E
)
16 -
---l-l i
i 0
1EO 1E1 1E2 1E3 1E4 1ES 1E6 Time (seconds) ecas9s to
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I
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l Comparison of AP600 to Standard Westinghouse 2-Loop Plant l
r 1
\\
i Plant Feature AP600 Standard 2-Loop Plant NSSS Thermal Power 1940 MWt 1880 MWt 1
(Power / Volume)
(1.14 kw/ft')
(1.45 kw/ft')
Containment Diameter 130 ft.
109 ft.
I I
I 8
8 Net Free Volume 1.7 x 10 ft' 1.3 x 10 ft i
Approximate Exposed Mass Avaliable for Heat Sinks I
Concrete 14.7 x 10' lbm 14.3 x 10' lbm i
Steel 7.8 x 10' lbm 1.9 x 10' lbm j
Long-Term Heat Removal Passive Cooling Active systems f
1 i
Acas 9fa7 11 I
O O
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t NY i
ii DBA Containment Pressure Regulation l1 Reactor containment shall establish an essentially i
leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are l
not exceeded for as long as postulated accident I
conditions require. (Criterion 16)..
1 l
ACRS 9FJ7 12 i
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4 i
i I
I E l
i DBA Containment Pressure Regulation i
The system safety function shall be to reduce rapidly, f
consistent with the functioning of other associated systems, the containment pressure and temperature i
i following any loss-of-coolant accident and maintain i
them at acceptably low levels for onsite and offsite electric power system operation assuming a single failure. (Criterion 38)
/cas9st 13 a
i
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i i
- ii
~
DBA Containment Pressure Regulation i
l The containment structure should be able to l
t i
accommodate the calculated pressure and
}
temperature conditions resulting from any LOCA.
This is to be accomplished without exceeding a l
design leakage rate and with sufficient margin. The i
margin should reflect consideration of (1) potential l
l energy sources... (2) limitations on the amount of
}
information available on accident phenomena, and r
(3) conservatism in the calculations (Criterion 50).
1 i
i 14 ACRS 9S
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~
Accident specification i
4 i
Containm.ent Pressure Criteria I
P, sign (45 psig) New methods for AP600 l
P
<=
o peau
(-3) psig SRP methods
-P
>=
min 5 psi SRP methods i
. AP
<=
mmgmont i
T,qo;pment(time)
SRP methods l
l i
I l
ACRS 91.f7 15 I
)
U
^h l
l Accident specification L5 n:
Criteria spe~cifically supported by the PIRT Documentation in an application for design certification should include:
evidence that the performance of each safety feature of the design has been demonstrated through either analysis, appropriate test l
programs, experience, or a combination thereof f
evidence that sufficient data exist on the safety features of the i
design to assess the analytical tools used for safety analyses over a sufficient range of normal operating conditions, transient conditions, and specified accident sequences (10CFR52.47(b)(2)(i)(A)(1) )
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Acas 9 97 16 l
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I ii Test and Analysis Process
=
Evaluate Distortions Validate Models and Correlations for Scaled SET PIRT; Condensation (LST, Wsc)
Identify and Rank Evaporation (G&S, Rat Plate) l Phenomena WCAP-14845, Rev 2 6*d III Above-deck Stratification (LST, Others)
Water Coverage (LST, WDT, WFPT, SST)
WCAP-14812, Rev 1 PCS Air Row Resistance (1/6 Scale)
Circulation (International Database)
Evaluate Distortions 4
for Scaled IET Confirmation of Lumped Parameter l
Phenomena Scaling,
--+
Biases and Capabilities Validate PIRT WCAP-14845. Rev 2, i
Dimensionless Groups Sea ill WCAP-14407, Rev 1. Sect. 9.1.2 & 9.2.3
. AP600 Range Develop Conservat.rve WCAP-14845, Rev 2. Sect il tegies / Wels WCAP-14812. Rev 1. Sect. 4.4
{
Select Computer identify Code Biases Apply Biases to Models and inputs Predict Plant Code and Capabilities Performance
+
WCAP-14382 WCAP-14407, Rev 1 l
^
WCAP-14407 Rev 1, Sect. 3 Sect.3, Sect. 9.2.4 SSAR 6.2 f
3 and d9C WCAP-14967 and Sect. 9.C.3 ACRS 95J7 17 I
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