ML20128G892
| ML20128G892 | |
| Person / Time | |
|---|---|
| Issue date: | 05/24/1985 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| FRN-51FR12502 AB76-2-15, ACRS-T-1410, NUDOCS 8505300344 | |
| Download: ML20128G892 (184) | |
Text
ORIGINAL UNITED STATES OF AMERICA le's NUCLEAR REGULATORY COMMISSION l'sY In the matter of:
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS Combined Meeting of ACRS Subcommittees on Metal Components and Structural Engineering Docket No.
^
.'\,_
/ )'s Location: Washington, D. C.
! Date: Friday, May 24, 1985 Pates: 244 - 410 ACR80ECECDPYQ"'"f Jo \0~: PgayAflgLAlls0"cr Court Reporters 1625 I St., N.W.
'd Suite 921 Washington, D.C. 20006 8505300344 050524 T 41 PDR
244 1 UNITED STATES OF AMERICA
-U
[) 2- NUCLEAR REGULATORY-COMMISSION S
4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
- 6 COMBINED MEETING OF ACRS SUBCOMMITTEES ON 7 METAL COMPONENTS AND STRUCTURAL ~ ENGINEERING 8
9 Room 1046 10 1717 H Street, N.W.
11 Washington, D. C.
12 Friday, May 24, 1985 la The Subcommitte on Metal Components and the Subcommittee
(
14 on Structural Engineering of the Advisory Committee on Reactor 15 Safeguards convened, pursuant to notice, at 8:30 a.m., Paul 16 Shewmon, Chairman, Metals Components Subcommittee, presiding.
17 PRESENT:
18 PAUL G. SHEWMON, Cha i renan 19 C.P. SIESS, Member 20 JESSE C. EBERSOLE, Member 21 HAROLD ETHERINGTON, Member 22 ROBERT C. AXTMANN, Member 23 CARLYLE MICHELSON, Member 24 J. HUTCHINSON, ACRS Consultant 25 E. RODABAUGH, ACRS Consultant
r;c 245 1 __ PRESENT (Continued)*
- h. 2'
~
MYER BENDER, ACRS Consultant 3 S. BUSH, ACRS Consultant 4 ACRS Staff Member:
'5 ELPIDIO IGNE 6 SPEAKERS:
7 L. Shao 8 R. Vollmer 9 B.D, Liaw to B. Bosnak 11 R. Klecker 12 C. Serpan 13 S. Hou
.L-14 J. O'Brien 15 W. Johnston 16 B. Elliot .
17 W. Shack 18 Mr. Vagans 19 Mr. Shields 20 21 28 23 24 25
246 1 __ p ROCEED i NGS
-'(_j A) 2 MR. SIESS: Good morning. This is a continuation of a the meeting that began yesterday to hear reports from tit.e 4 representatives of the piping Review Committee.
5 We will proceed with item 2.4 on the agenda, 6 Mr. Bosnak.
7 MR. BOSNAK: Good morning. I'm Bob Bosnak, the 8 Division of Engineering, NRR.
9 A couple of loose ends from yesterday that Carl 10 Michelson asked a question about. LARs and snubbers. We 11 checked, and currently, unless the plant that has the 12 defective snubber cannot make the replacement within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />,
\
[ 18 then he has to come down and then something is required. But 14 If he does exchange the snubber for a good one within a 15 72-hour period, there is no requirement to come in and report.
16 Optionally, some do, and what we have heard from 17 checking with a few regions, some don't. So that is the 18 current status with the record.
19 MR. SHEWMON: Does that also mean it doesn't get 20 caught by NSTD or whoever that outfit is?
21 MR. MICHELSON NpHDS.
22 MR. BOSNHK: We were unable to contact AEOD. There 98 was no one over there vesterday to olve us that particular
-m 24 roolv. But we did check with the reolons, and with respect to f s
(
PM submittino an LER, if they can do it within the 72-hour
m_
247 1 period, there is nothina.
((D) 2 MR. SHEWMON: Fine.
3 MR. BOSNt4K : One other loose end here that I wanted
'4 to make sure we understand.
5 CSlide]
6 This is the primary loop, and l'm going to come back 7 to this if you would like, but I want to show you where the 8 break locations are.
9 CSilde3 10 This is the Westinghouse plant, and I think we 11 talked about 11 yesterday. Actually, the number being done 12 away with with leaks-before-break is really eight, and if you 18 look at the numbers that you see here, the BR means branchs g, 14 10 and 11 are branches. The 7 is the longitudinal split in the 15 elbow. All the other breaks are the breaks that are being 16 eliminated.
17 The branch lines stay.
18 CSilde3 Ig The three-dimens;onal view that you have here just 20 shows one of the lines, and that would be a location for a 21 break, pressurizer surge line.
22 MR. SHEWMON: The break that is postulated there 23 would have to be defended against jets? Or was there a whip 24 in the minor line or what?
25 MR. 803NAK Everything is as it always was.
248 1 .. MR. SHEWMON: So that also means the whip of the O
( ,/ 2 main lines of these elephant cages stay at least for those.
3 MR. BOSNAK: it is this line that is breaksng.
4 MR. SHEWMON: The little one, not the big one.
5 MR. BOSNAK: The little one, not the big one. It's 6 the terminal end of the branch line.
7 MR. SHEWMON: Okay.
8 MR. MICHELSON: Is it clear to you from the 9 Commission paper that that is what is meant by reactor coolant 10 piping?
11 MR. 803NAK: It's clear to me.
12 MR. MICHELSON: It's not clear to me.
[)
\J 19 MR. BOSNAK perhaps I'm too close to it, but if 14 it's not clear, that is exactly what is being meant by the 15 Commission paper.
16 MR. O'BRIEN: The reason it is clear in the 17 Commission paper is that the Commission paper says that it's 10 based --
19 MR. O'BRIEN: The Commission paper is based on the 20 resolution of A-2 and what is performed by NRC contractors, 21 and that work is based only on the hot leg, the cold leg and 22 the cross-over. So by inference, since we cite the resolution 28 of A-2 and we cite the work performed by NRC contractors, then fs 24 by reference it means only those breaks that Bob indicated.
(
25 MR. MICHELSON: I am glad you know that because i
249 1 dLdn*t from just reading the material in front of me, and I b.
s, 2 would have thought that a document such as a ru6emaking would a be self-contained or very expli' cit where it isn't 4 self-contained as to where to find the information. Even by 5 reference it would be fine, but I couldn*t find a reference to 6 tell me what the definition of primary piping was.
7 So I'm surprised in a rulemaking that i t .ls that 8 soapy.
9 MR. SIESS: We can always say the lawyers are 10 right and the rule was bad, but I don't think that's true.
11 MR. BOSNAK: Now what I would like to go into la 12 hopefully to try to clarify for Carl Michelson and Jesse 13 Ebersole, particularly, the questions that were raised with x
14 respect to what is going on on plants that are in the 15 licensing strain, While we are commenting on it --
16 CChart3 17 1 don't want to confuse the issue, but i think all 18 the questions that were asked, we need to have a little 19 further discussion on. I'm calling these all design 20 improvements. Here we have NTOLs. These are the plants that 21 haven't been licensed. Here we have operating plants and here 22 we have Cps. Of course, there are no Cps right now, but some 23 of the questions that were asked get into what you might call 24 the general rule. I'm calling this now -- this is the limited 25 rule, the primary loop for pWRs.
250 1 __ Eventually, the general rule -- you know, it's not JQ(,,
2 limited to pWRs, but right now let's focus on the specific 3 rule. And NTOLs --
I will put a little check mark here. Now, 4 others -- and by others, I mean other than the primary loop.
5 We have had requests. They are in house. But there is no 6 action being taken on other, so this is request.
7 principally what they are -- and Ray can correct me
, e if I have left out a few --
but the pressurizer surge line 9 that you saw there, the Class 1 --
typically the Class 1 10 branch lines. They are the same materials that you heard 11 spoken about yesterday, but we have taken no action on it and 12 we Intend to take no action in the immediate future. So 13 basically now we are talking about the primary loop.
(
14 I will get into this a little bit later, but this 15 stands for the arbitrary intermediate breaks, and this is the 16 things that we talked about yesterday, try(ng to put 17 everything together on flexible piping.
18 MR. SHEWMON: la that first word damping?
19 MR. BOSNAK Yes, damping and spectral shifting.
20 Those two design improvements.
21 On the OLs, as far as requests are concerned, we 22 have the issue A-2. They need this limited action that we are 23 taking. And again, these are all pressurized water reactors.
24 The CE plants also, since they have not yet gone through the
>O 25 --
the operating plants have not yet gone through the GDC-4 --
251 1 a r,e looking for this particular effect, LOCA and SSE. By that
-(
( 2 1 mean decoupled.
3 We have had some preliminary requests from OLs 4 looking for design improvements, and by that I mean there are 5 two plants that i know of that are expected to come in 6 shortly. They are having problems with the reliability of 7 large steam generator snubbers, and we are talking about 2000 8 kips, 2 million pound snubbers.
9 What they would like to do, when the material 10 aspects of leak-before-break have been improved for their 11 plants, would be to do something for the snubbers. One is in 12 a low seismic area. The other is in a high seismic area. I 13 (d T 14 don't know wha
- the end result will be, yo to a smaller-size snubber.
perhaps it will be to perhaps the low seismic plant 15 could totally eliminate the snubber. I'm not sure.
16 But in the context of your letter of June 14th --
17 let me quote from it -- because we are looking for a 18 clarification in this area. I can tell you how we a.*e to interpreting it, and then we would like to we co..weiwd of 20 this is not your intent. But you co sa3. "ils.. w w w , un.y 21 relaxation of requirements to c.y. iii. LuuL ...walJ Ju 22 preceded by rigorous rwenam;...;;s.. wf L..a i r. L .u. I l y ws 1.w.99 23 component sup,aor t e ..e Per n i ef 11ti;* *a*>1l-a* **
24 Ida don't intend to tauch whet m8qht be chargc+mrized e P, .- 9 *53 eacie r e - . . ., . -m-p-agat e ypa*+3 S.,t if we do have a
252 i.nu _. ' ' : ~. -- :-f ; r. .rc i s ?' !a3 sbout operating plants now
. ,n -
t \ *
(_,/ 2 --
>rcr- ..
u't/ t' t h a r: problems such as I have reported --
? c. r. c agc'n, 'h'. i .s a preliminary report. We don't have i r e s/+ b 8 rg from the utility yet. These are all what we have heard from telephone conversations via second parties.
6 So we do want to be sure that if we take an approach 7 such as that, that it would be in consonance with your r 8 wishes. We think we understand what you are saying because we )
l 9 don't want to disturb-the heavy component supports either.
10 The work that Livermore did and the work that --
particularly 11 that Livermore did, that stressed the effect of Indirect 12 components -- we are talking about things such as cranes 13 toppling over, things that might Indirectly cause a pipe A
14 break, not causing the pipe break, but Indirect causes.
15 MR. SHEWMON: I think another part of that history 16 that may be irrelevant but sits in the back of our minds is 17 about some supports you had which were heavily constrained in 18 their weld design and built up material which had a ductile, 19 brittle transition temperature around room temperature. Where 20 was that, Spence?
21 MR. BUSH: That was a lot of places.
22 MR. BOSNAK particularly North Anna was one.
23 MR. SHEWMON: North Anna was where it hit the fan, I
( 24 guess, but in general, that sort of thing. Also to be sure l
l 25 that they would maintain their integelty.
i
253 1 __ MR. BUSHr Bob Nichols spent, I think, two years on
,m ks _) 2 that at EPRI, c.d recently, I think, wrapped it up, which 3 essentially was an assessment of what the properties were on 4 the supports, and as far as I know, Bob, a pretty large 5 spectrum of plants, anything that they thought had it. A lot 6 of that was A-36, as I recall, which is not exactly the 7 world's best material.
8 MR. ETHERINGTON Even so, the general conclusion 9 was that it's not really a problems isn't that right?
10 MR. BUSH: I think it was not considered to be a 11 major problem.
12 MR. BOSNAKt Certainly on these plants, the NTOLs 13 and the OLs are not changing anything. They are designed for
.{
14 the combination LOCA and SSE, and nobody is changing 15 anything. As I said, the only thing we have heard, there may 16 be people that are interested in improvement, and these are on 17 operating plants, it is in the area. The only thing that we le would even entertain, I believe, at this time would be looking 19 at how do we improve the reliability of snubbers that are 20 there because there have boon problems.
21 MR. MICHELSON: Dons this mean, thun, that the 22 request from Seabrook for the feedwater line arbitrary breaks 23 -
you haven't talked about the arbitrary yet.
24 MR. DOCNAKt I haven't come to that.
A C5 HR. MICHELSON Except for arbitrary, this is the m
254 1 s.l_t u a t i o n .
. ,m i \
\ ,/ 2 MR. BOSNAK: Arbitrary breaks, and unfortunately a they are in~the same volume as'the fracture mechanics area 4 because they are pipe breaks. These are pipe breaks here.
5 These are what I call improvements in piping design to achieve 6 what we consider to be flexible piping. They are all in the 7 Piping Review Committee report. This is the thing that is now 8 before the Commission, and I wanted to be sure that everybody 9 understood what we were doing there and that we are making to very little change.
11 MR. MICHELSON: Is it clear from the Commission 12 paper that it doesn't include arbitrary breaks?
13 MR. BOSNAK 1 think so. It does not include 14 arbitrary breaks.
15 MR. MICHELSON: I thought it included all the breaks 16 in the primary piping.
17 MR. BOSNAKt Again, we don't want to mix these two 18 areas up. The elimination of breaks based on advanced 19 fracture mechanics techniques is one principle. Arbitrary 20 Intermediate breaks, which is just the elimination of these 21 breaks ~~
l will tell you what the trade-off is when we get to 22 those -- is a completely separate area. Nothing to do with 28 the advancing to GDC-4. The fact that they are also 24 eliminated is just a coincidence, 1 guess, if you will. But 25 they are two separate items.
255 1
MR. EBERSOLE: I may have missed this, but i A
'/ 1
( ). 2 understood you were going to probably permit the removal of 3 motion limiters.
4 MR. BOSNAK: What we are talking about with respect 5 to this, as John characterized them, we are trying to get rid 6 of the evil pipe whip restraints. What people are doing are 7 getting rid of pipe whip restraints, bumpers. If that is what 8 you characterize as being motion limiters, that's correct.
9 Those are in the primary loop. If people want to leave them 10 there, they can leave them there. What I think many of the NG 11 welds are going to do, they are not going to put in saddles 12 and they are going to shim them.
['D 13 MR. EDERSOLE: What about the main steam lincs?
14 MR. DOSNAK: We are not talking about the main steam 15 lime right now.
16 MR. EEERGOLE: Okay. ,
17 MR. BO8NA%r This is the primary loop only. I think te we had thu slide of the primary loop before you came in, 19 exactly what we are talking about. This is not main 20 steam, it's a pWR primary loop only.
El Now cps. Obviously, if had somebody wanting to come 22 in and build a new plant, I'm sure if 1: was a pressurized 23 water. reactor, they would ask for that.
24 MR. ESERSOLE: How was it rationalized since these i
25 are pWHs and they don't get the cracks anyway? That's the way
l 256 l
1 1 l_ understand it.
/'N
(,) 2 MR. BOSNAK: That's the reason why we started 3 here. We started with the primary loop because it has been 4- good operating experience. There were no large dynamic 5 loads; Apparentiv i should list some of-those things.
6- MR. EBERSOLE: Isn't it true that the need for 7 detailed and frecuent inspection is a good deal less in the 8 pWRs than in the boilers?
9 MR. BOSNAK: If you are talking about durina 10 construction?
11 MR. EBERSOLE: No.
12 MR. SIESS: 188.
la MR. BUSH: There is no difference. Unless --
I think 14 l can speak with reasonable authority on this -- Unless you 15 are faced with requirements established by the NRC in addition !
16 to the code requirements, you won't have any difference. Now, 17 the reason I say that that way is if you have sensitized 18 stainless steel in there, then NUREG 313 tends to control and 19 you do more inspection In the case of a boiler than you would 20 in pWR.
21 MR. EBERSOLE: lan't that controlled in the engine 22 room?
23 MR. SIESS: These are only DWRs, pWR primary system 24 only, primary loop only.
25 MR. 90SNAK If you want, we could have a laundry
257 1 LLst here, but these were the things that were looked at
, (_f 2 before we decided to even go into this primary loop: that we 3 had leakage detection, there was quality in construction, that 4 we knew the loads. If you don't know the loads, you are going
=
5 to have difficulty getting into your fracture mechanics if 6 your loads are uncertain.
7 When you start getting into some of these other 8 lines in the balance of plant, that is what you are going to 9 be faced with. And of course, the material, to understand the 10 material and how it behaves, and whether it will leak before 11 It breaks.
12 So those kinds of things are inherent in many years 13 j
(%. of work by the Staff before we were able to say that we l 14 believe the primary loop of a PWR is not going to -- it's
- 15 going to leak before it breaks.
16 With that in mind, what we were trying to accomplish 17 was really the removal of all of this mass of steel that you l
l 18 have seen. That's the objective.
I
! 19 MR. ETHERINGTON: Did you say it's not going to leak 20 before it breai<s?
21 MR. a
'lESS: His sentence wasn't a good sentence, 22 Harold.
28 MR. ETHERINGTON: I thought that was misspoken.
24 MR. SIESS: He did misspeak.
\'
25 MR. BOGNAK So in the OLs, we don't expect they are
258 1 going to get into this area of the other lines --
p
( ,, 2 MR. SIESS: The other lines are the broad-based 3 rule? Is that what you mean by others?
4 MR. BOSNAK: The broad-based rule says that the 5 technique, the advanced fracture mechanics --
6 MR. SIESS: I just want to know what that column 7 refers to. The first column refers to the interim schedule of 8 exception. The second column is the broad-based rule.
9 MR. BOSNAK: Yes.
10 MR. SIESS: Okay.
11 MR. BOSNAK: I just wanted to point out there are 12 requests in house right now even though the broad-based rule 13 has not even been looked at that goes beyond the primary loop, 14 and we are just sitting on it. We are not doing anything with 15 them. So I think that's all 16 If that is fairly clear, perhaps we can move to the 17 next column.
10 MR. SIESS: That takes care of the rules, the two 19 rules that we had.
20 MR. BOSNAKt Yes. Again, this is the limited rule 21 that is before the Commission right now. We think it is 22 fa!rly clear, it's very finite. people are not going to 23 change equipment qualifications, they are not going to change
-w 24 heavy component supports, they are not changing ECCS, not
~
25 doing anything to containment.
259 1
MR. SHEWMON: How about pressure in compartment?
2 MR. BOSNAK: pressure in compartment stays the same.
8 MR. O'BRIEN: The rule does say that pipe 4 dispressurizations can be eliminated from the design basis.
5 MR. SIESS: Asymmetric loading is affected? That's 6 a compartment break.
7 MR. O'BRIEN: There are pressurizations due to 8 breaches in the primary circuit from steam generators and 9 seals. That is still in the design basis. The only thing 10 excluded --
11 MR. BOSNAK: The A-2 aspects of pressurization 12 are the things that are going. When I said pressurization and
['N 1,
18 I answered it stays the same, it does except for the 14 asymmetric effects.
15 MR. SIESS: Mike.
16 MR. BENDER: I guess I'm reading something into this 17 that you didn't say. For the plants already designed with the 18 double-ended pipe break loads providing the basis for the 19 compartment pressures, there is not likely to be any change at 20 all. That could only --
21 MR. BOSNAK: That's correct. That's why l'm saying 22 It stays the same. So the things that we are talking about 23 here, they are not going to change.
7s \ 24 MR. BENDER: So that the thing that John O'Brien is 25 talking about really has to do with future designs where you
260 1 might, in fact, look to see whether in changing the
?
)
' (,/ 2 double-ended pipe break criteria for primary loops, pressures 3 might drop some.
4 MR. BOSNAK: 'There is one other wrinkle on it, since 5 John mentioned it. We realize today we have what we ca l l 6 break exclusion regions, and we have limited displacement 7 breaks. These breaks that we see here --
t 8 CSilde]
9 -
particularly in the area of the reactor. coolant 10 pump steam generators, there are bumpers so they are limited 11 -displacement breaks. What we are saying is if you want to 12 remove that bumper, then they are no longer limited 18 displacement breaks.
( They were designed for limited 14 displacement breaks, but the design doesn't change. You have 15 in there the peak pressures that are associated with the 16 limited displacement breaks. That's not changing. But you 17 'can remove the bumper.
18 MR. SIESS: They were limited displacement breaks 19 because if you assume the double-headed gulliotine break, you 20 have got too much pressure, so you have limited the 21 displacement to where it couldn't be double-headed.
22 MR. BOSNAK Correct.
28 NR. SIESS: And now that you do not require the 24 double-ended break, you can remove the limited displacement 25 device.
261 1 __. MR. BOSNAK: That's correct.
[
( 2 MR. MICHELSON: And still use whatever the pressures 3 and temperatures and so forth were before.
4 MR. BOSNAK: That's correct.
5 MR. MICHELSON: Let's postulate for a moment that 6 somebody has got their environmental q'ualification on a 7 particular device in that region, and it turns out the; 8 qualification was inadequate because they couldn't quite pass 9 the test for the particular pressure, temperature and 10 humidity. Are you now going to give them relaxation, then, on 11 that test, or are you still going to make them meet that 12 original requirement?
'[ 13 MR. BOSNAK We haven't heard of anybody having any
\-
14 problems on meeting it.
15 MR. MICHELSON: It will get more so when you get 16 over to the outside of containment.
17 MR. SIESS: We are still on that first column.
18 MR. MICHELSON: Right. I just want a clarification.
19 MR. BOSNAK Inside containment you have the basic 20 pressure, temperature, moisture, humidity that you have always 21 had, and that doesn't change.
22- MR. MICHELSON: These vary in subcompartments within 23 the containment, of course. You get much higher temperature 24 --
t 25 MR. BOSNAK It can vary, but our experience is --
L
262 1- __ MR. SIESS: Carl, you are saying that if you had l'8
- 4 (s ,/ 2 calculated the environmental temperatures and pressures for 3 the limited break, and now you recalculate them for the leak 4 size break, which is permitted under the rule, that you think 5 it might be worse?
6 MR. MICHELSON: No, no, that isn't it at all. Of 7 course I assume that you are going to have very modest 8 environmental conditions for the limited leak before break.
9 In fact, I'm not even sure how they would set that. The 10 question is, if you found out during your equipment 11 qualification program that you could not pass the test, could 12 you go back now and ask for a relaxation on the basis that you 18 J
} are not going to have a break there anyway?
14 f1R . SIE3S: I think if the rule went through, you 15 would not have a break there. Then you would check the 16 qualification for the leak size break. Am I correct, Bob?
, 17 And if you had --
i 18 MR. BO3NAK: What we said with respect to equipment 19 qualification, as we have with respect to ECCS, is that it 20 doesn't change.
21 MR. MICHELSON: You said that although you didn't 22 say it in the rulemaking.
23 MR. SIESS. Let's go away from the NTOL to a Cp or a f-s 24 step beyond. We would now be quallfled for the new criteria, 25 which would be some much smaller leak than the limited break
m 263 1 leak.
( , 2 MR. BOSNAK: We would depend on our systems people a to tell us what the temperature and pressure environment was 4 with respect to the equipment.
5 MR. SIESS: They would use leak size based on 6 fracture mechanics.
7 MR. BOSNAK: I would expect in the future that might 8 hsppen.
9 MR. MICHELSON: I would hope not.
10 MR. BOSNAK: All of that would have to be reviewed.
11 We don't have a position on that, but we do have with respect 12 to where we are today and what is covered by the rule.
'Og 13 MR. MICHELSON: They heve no position in here on W/
14 what they are going to do. I think that is wrong.
15 MR. SIESS: That's the case-by-case business.
16 MR. BOSNAK: That would all have to be developed and 17 would be developed over a number of years in consultation with 18 this committee, certainly.
19 MR. M I CHE L SON : 1 personally feel that the 20 rulemaking ought to make it very clear that the environmental 21 conditions stay as they were. Rulemaking remains silent 22 now. People can come in and start playing with it.
23 MR. DOSNAK I have read statements, and John can fs. 24 correct me, that these things don't change.
f )
25 MR. SIESS: John, we keep hearing you say that but
, _ - _ . . - ___ . __ _ . _ . . . ____m 264 1 we,can't find the words in the rule that says that.
R k ,) 2 MR. O'BRIEN: In the earlier version of the rule, it 3 specifically said equipment qualification is not affected.
4 MR. SIESS: You are standing by the mike but you are 5 not talking in the mike.
6 MR. O'BRIEN: In an earlier version of the rule, 7 there was explicit statement that ECCS containment ano 8 equipment qualification is not impacted by this rule. That's 9 . what you want to be said.
10 MR. MICHELSON: Yes, and you removed it.
11 MR. O'BRIEN: However, to get NRR concurrence, they j 12 said delete it because we may on a case-by-case basis want to 18 change equipment qualification too. This was not an 14 oversight. They debated it, and they said, we don't want to 15 say specifically equipment qualification, so that is an NRR 16 decision. ,
17 MR. MICHELSON: So that remains open and they can i
.! 18 now change it, although I'm surprised, since there is a whole 19 tot of history on environmental qualification, how you can l
20 change it by just remaining silent. But now they want to 21 remain silent and think they can change it.
22 MR. BOSNAK We don't expect anything to change. '
23 MR. MICHELSON: I realize you keep saying that, but 4
24 you won't put it in words where it counts, j 25 MR. SIESS: Mike.
4 4
- - , . --y, - , - - - , - , _ , . - .-_,..m,_,.,-,,,-.---.,-w..,-- e. -,,--,.3,--e.--..m , --.~ ~ ~---
m.----,--.-----.-,--,-,.m... ,
265 1 __ MR. BENDER: , I think Carl has some good points, but
]m)
\/'% 2 it seems to me the way the Staff is proposing this thing gives 3 a.little bit of flexibility that is reasonably desirable.
4 Now, it might be better to say something in the rule that 5 indicates in most cases the regulatory staff anticipates no 6 change in the environmental qualification condition. But 1 7' can conceive of places where the requirements are so severe 8 that it is creating a situation where you can't put a very 9 useful instrument in a place where it would do a lot of good 10 because of some arbitrary environmental conditions.
11 As a matter of fact, as you know, people are moving 12 a lot of these instruments out to the ends of long lines where n
I I 13- the sensing capability has been badly degraded because 14 environmental qualifications are set in a very arbitrary way.
15 1 think from a practical standpoint it would be 16 desirs.ble for the Staff to have that flexibility, but the 17 flavor of it is the thing you are talking about, and there is
+. - 18 a lot of merit in trying to phrase it in that way so that it 19 doesn't encourage people to make changes just because they 20 have got the opportunity to do so.
21 MR. MICHELSON: What I would really like to see is 22 what you suggest plus a few words to the effect that the Staff 23 is still looking at'the failure of other than pipes to 24 determine what environmental effects it would have because 25 there may still be far greater leaks possible than the o
5 - - - , . _ _ . . _ _ _ - . - _ _ _ _ _ _ _ _ _ _
- - - =
266 1 postulated detectable leak under this rule.
~
s,) 2 So I think the issue is far from closed by just 3 saying environmentally qualified only for the leaks they I
4 detect.
5 MR. SIESS: If it is other pipes you are concerned 6 about, it is clear that won't change.
7 MR. MICHELSON: Not other pipes; other conditions.
8 MR. BUSH: Those have been looked at in considerable 9 depth, and I don't know of any case -- for example, tops of 10 valves and things of that nature where they represent leakage 11 greater than this because if we talk with, say, a 10 percent 12 upper bound on that, we looked at that years ago with regard I 13 to zipper effects and so forth where you get a series of U
14 failures, things of that nature.
15 MR. BOSNAK: I wouldn't be surprised in a few years 16' if we are' talking about what we are going to do with new 17 plants when we looked at this whole area, instead of being 18 very mechanistic with respect to what is going to cause the 19 effect,.you might be very proscriptive and say as far as the 20 environment is concerned, here is what you have to have to 21 qualify in inside containment.
22 I would see us perhaps going in that fashion.
23 MR. SHEWMON: It seems to me when the Germans came I
i 24 through with something about like this, or their removal of 25 this, they said you will postulate only a one-tenth
267 1 gross-section area fracture.
2 MR. BOSNAK: They still keep the whole area for 3 containment for equipment and for supports.
4 MR. BUSH: That was completely arbitrary too.
5 MR. BOSNAK: An arbitrary, non-mechanistic break.
6 MR. SHEWMON: Have you thought about something like 7 that saying there is no pipe whip, but instead of how many 8 gallons will come out the size of some darned crack, just 9 - saying we will reduce it by an order of magnitude and that is 10 what they will design for?
11 MR. BUSH: It was discussed at areat length.
12 MR. BOSNAK: We thought about it and we are still
/ 18 thinking about it.
14 MR. SIESS: I think what Carl Michelson's concern 15 is, and if I understand it right, 1-certainly share it, the 16 double-ended guillotine break has been accepted for many, many 17 things as an upper bound, as a result of which you didn't have 18 to check certain other things. If you assume the double-ended 19 guillotine break for equipment qualifications and so forth, 20 that was an upper bound and you didn't have to look at other 21 - things.
22 Once you remove that upper bound, you either have to 23 look at those individually or settle on something else as a
,-w g 24 new upper bound, and I think this is the thing you have got to t
25 worry about.
s- , , ,-ym----3+, - -- r-, m-m---,--,.,-,.w-- -
- . - ---.---,.-.,-v-- r, - . . . - - - - - - - . - , - - - - , - - - - - - - - - - - - - - - - - - -
268 1 __ MR. BOSNAK: Nobody disagrees with that, f
( ,/ - 2 MR. SIESS: The. things we have been neglecting a because we were comfortable with this upper bound in this 4 particular area. What the rule ought to say is we have not 5 decided what the effect is on equipment qualification, or some 6 word that gets equipment qualification in there.
7 MR. MICHELSON: Or and leaves it as it is.
8 MR. BOSNAK: That is definitely the intent.
'9 MR. SIESS: Let's don't leave it as it is, but that 10 it be done case by case, if necessary, because it may not make 11 a difference.
12 MR. BUSH: Could I make a comment on a positive O)
' \m /
18 aspect I don't think Bob has put up there? If he were to have 14 that diagram back on, if you were to look at the tech specs on 15 most of the plants now, you will find that all of thost welds, 16 the nozzle welds, et cetera are exempted from inspection. You 17 can't get to them very straightforwardly. There is no way you 18 can inspect them.
19 Therefore, of the primary system, probably a third 20 of the welds you forget about because they are inaccessible, 21 and something I would see as a benefit --
not that i expect 22 them to break, but you certainly would like to be able 23 to monitor things and see if anything is happening --
would be 1
24 that once this garbage is removed, we will have access, and i
'd 25 then, of course, it would revert to the required inspection.
7- .
269 1 __ MR. SIESS: Carl Arlotto had an answer, or a 7m.
x_sl t
a question?
3 MR. ARLOTTO: I've got a comment. I think, 4- Mr. Chairman, the comments made, particularly by Carl 5 Michelson, and the concern of others, are well taken. I think 6 from a procedural viewpoint, I think it is time we recognize 7 that this is going to go out for comment. I think the 8 combination of the comments we get from the public, the 9 comments that we get from the committee, the things we have 10 heard now, will somehow make us write the final rule within 11 the context of this particular-discussion.
12
~
I think the key item -- and Bob Bosnak has said it
/ \ 13 several times -- is we are really pushing to get rid of the b;
14 piping restraints. We can do that by just saying we are not 15 going to be doubling the pipe breaks in the primary system of 16 pWRs. That will do us a great deal of goop even if we 17 continue to say that the area for design, that is, the break 18 area for design were the same. Just eliminate the doubling of 19 pipe breaks. You are not going to get the whip even if you
(
l 20 did get a split equivalent to that, which we don't see how you l
21 can do it.
22 Secondly, I would like to observe that most of us
- 23 who have taland to the Germans regarding the 10 percent break l.
fg 24 have concluded that it was a pretty arbitrary decision that l
V 25 they have made. They do not seem to have the data to support l
r L.
270 1 that. decision, and I think that we are now -- if I can now y
((m,)
2 combine the two offices, NRR and Research, we are now in the 3 process of looking at a research program associated with 4 degraded piping, and hopefully perhaps we can put some meat on 5 the bones of fracture mechanics and come up with a definitive 6 upper bound kind of a. break, but right now we just aren't 7 there.
8 But I think the stuff that we have been talking 9 about must be cleaned up, I think at the final rule stage.
10 This part of the process we are going through.
11 MR. SIESS: I would have thought that 10 percent was 12 not a whole lot more arbitrarv than 100 percent.
I- 18 Jesse, did you have a question?
14 MR. EBERSOLE: I remember back in the early BWR davs 15 one of the more horrendous piping failures was to imaaine a 16 vertical split in one of the risers that would create a steam i 17 and vapor election process that would create a monster 18 centrifuge round and rounc the drywell and literally strio a 19 tot of the instrumentation off that was needed to mitigate the 20 consequences. You know, like the level columns, et cetera, et 21 cetera.
22 GE' invoked the notion that they had 180 degree 23 equater logic, which has a flaw in it that you only loft half 24 the instruments. That didn't permit the random failure of the k
25 first track to mitigate.
e e
271 1 __. When you aat into environmental cualification, what f
k 2 l'm hearino is you are lust about eliminating the dynamic 8 effects of lets on such equipment. You may permit, and 4 certainly the industry is likely to hop riaht on it. the 5 actual. mounting of critical and sensitive equipment right on 6 the pipes they are monitoring, from which they are taking 5
7 their instrument taps, because you are eliminating the notion 8 of pipe bursts and just saying that pipes drip.
9 1 can't get it quite through my head yet that pipes 10 don't burst and they only drip, and that seems to be the way 11 you are going. Am I wrong?
12 MR. BOSNAK: Here again, we are talking about the 13 primary loop right now, b[~'i 14 MR. EBERSOLE: I was, too.
I 15 MR. BOSNAK: I'm talking about a pWR, We haven't 16 gotten into the BWRs at all. And whether or not we are ever 17 going to be able to get through all of these situations here 18 with respect to loads, materials, what happens with respect to 19 aging of the material -- we started with something that we 20 thought we could be comfortable with.
l 21 MR. SIESS: Jesse, were you limiting yourself to 22 BWRs?
23 MR. EBERSOLE: No, I was being gent,al.
24 MR, SIESS: I think Jesse was basirIally challenging
( I 25 the --
..n.,--,-- , - , , , - - - - - - .
m 272 1 _ _ _ MR. BOSNAK: The elimination of jet.
-g 1
's ,/ 2 MR. SIESS: No, he is challenging leak before break.
3 MR. BUSH: He is challengina what I would. call the 4 probabilistic fracture mechanics work.
5 MR. EBERSOLE: To the degree of leak.
6 MR. BUSH: That effectively would say in these 7 systems you wouldn't have a problem. Now, vou may not believe 8 the numbers as such, but thev are certainiv very low number
- 9. MR. BENDER: I think i don't interoret Jesse as 10 savina quite what you are savina. I may be wrona in mv 11 understanding. It seems to me that what desse is succestina 12 is that this new proposal should not be taken as a license to
- 13 locate equipment or instruments or anythina else in an 14 environment where they miaht be threatened bv some break like 15 this lust because the relaxation alves vou the occortunitv.
16 MR. EBERSOLE: That is preciselv what haeoens.
17 thouch.
18 MR. BENDER: I understand that. All I am saying is 19 if there were some encouragement not to be too free with that 20 kind of action, you would probably be pretty happy, wouldn't 21 you?
22 MR. EBERSOLE: Yes, if I had some way to sav, oh. he 23 didn't mount this transducer on the very pipe the fluids of gg 24 which he was monitoring.
25 MR. BOSNAK: We do have that way of doing it, and I
273 1 know exactly what you are talking about because we were faced
,m x, 2 with all of this when we had to get into what we called the 8 break exclusion region. If you recall, this was back in the 4 seventies when we started with the BWR because we couldn't 5 take the break in the region between the inside and outside 6 various containments. So we had this annular region we 7 couldn't. (Je then applied that same concept to pWRs.
O MR. EBERSOLE: You couldn't take it in the rim of 9 the fluid --
did you get rid of them?
10 MR. BOSNAK: You couldn't take it because 11 containment would be breached, and that was the basic reason, 12 but people started putting vital equipment in close to the
/~
l 18 break exclusion region, and we then -- not because things
\
14 didn't break, but we didn't want those located there for fire 15 and other reasons. It is just bad engineering to not worry 16 about how your systems are arranged.
17 MR. SIESS: Carl, you are saying that if you had 18 calculated the environmental temperatures and pressures for 19 the limited break, and now you recalculate them for the leak 20 size break, which is permitted under the rule, that you think 21 it might be worse?
22 MR. MICHELSON: No, no, that isn't it at all. Of 23 course I assume that you are going to have very modest 24 environmental conditions for the limited leak before break.
25 in fact, I'm not even sure how they would set that. The
274
- 1. gyestion is, if you found out during your equipment L
g-< l
( 2' qualification program that you could not pass the test, could 3 you go back now and ask for a relaxation on the basis that you 4 'are not going to have a break there anyway?
5 MR. SIESSr I think if the rule went through, you 6- would not have a break there. Then you would check the 7 qualification for the leak size break. Am I correct, Bob?
8 .And if you had --
9 MR. BOSNAK: What we said with respect to equipment 10 qualification, as we have with respect to ECCS, is that it 11 doesn't change.
12 MR. MICHELSON: You said that although you didn't
- d
) 13 say it in the rulemaking.
l 14 MR. SIESS: Let's go away from the NTOL to a Cp or a i
15 step beyond. We would now be qualified for the new criteria, j 16 which would be some much smaller leak than.the limited break 17 leak.
18 MR. BOSNAK: We would depend on our systems people 19 to tell us what the temperature and pressure environment was 4
20 with respect to the equipment.
i 21 MR. SIESS: They would use leak size based on
?
22 fracture mechanics.
r a
23 MR. BOSNAK: I would expect in the future that might
-s 24 happen.
. D 25 MR. MICHELSON: I would hope not.
I
l l
275 l
1 _. MR. BOSNAK: All of that would have to be reviewed.
[~') ,
(_). 2 We don't have a position on that, but we do have with respect 3 to where we are today and what is covered by the rule.
4 MR. MICHELSON: They have no position in here on 5 what they are going to do. I think that~ is wrong.
6 MR. SIESS: That's the case-by-case business.
7 MR. BOSNAK: That would all have to be developed and 8 would be developed over a number of years in consultation with 9 this committee, certainly.
10 MR. MICHELSON: I personally feel that the 11 rulemaking ought to make it very clear that the environmental 12 conditions stay as they were. Rulemaking remains silent 13 now, people can come in and start playing with it.
-s 14 MR. BOSNAK: I have read statements, and John can 15 correct me, that these things don't change.
16 MR. SIESS: John, we keep hearing you say that but t
17 we can't find the words in the rule that says that.
18 MR. O'BRIEN: In the earlier version ~of the rule, it 19 specifically said equipment qualification is not affected.
20 MR. SIESS: You are standing by the mike but you are 21 not talking in the mike.
22 MR. O'BRIEN: tr,an earlier version of the rule, l'
23 there was explicit statement that ECCS containment and i
24 equipment qualification is not impacted by this rule. That's 25 what you want to be said.
276 1 _,
MR. MICHELSON: Yes, and you removed it.
[( j'i/ 2 MR. O'BRIEN: However, to get NRR concurrence, they 3 said delete it because we may on a case-by-case basis want to 4 change equipment qualification too. Th i s wa s not an 5 oversight. They debated it, and they said, we don't want to 6 _say specifically equipment qualification, so that is an NRR 7 decision.
8 MR. MICHELSON: So that remains open and they can 9 now change it, although I'm surprised, since there is a whole 10 tot of history on environmental qualification, how you can 11 change it by just remaining silent. But now they want to 12 _ remain silent and think they can change it.
( 18 MR. BOSNAK: We don't expect anything to change.
.%./
14 MR. MICHELSON: I realize you keep saying that, but 15 you won't put it in words where it counts.
16 MR. SIESS: Mike.
17 MR. BENDER: I think Carl has some good points, but 18 it seems to me the way the Staff is proposing this thing gives 19 a little bit of flexibility that is reasonably desirable.
20 Now, it might be better to say something in the rule that 21 indicates in most cases the regulatory staff anticipates no 22 change in the environmental qualification condition. But i 23 can conceive of places where the requirements are so severe 24 that it is creating a situation where you can't put a very 7w 25 useful instrument in a place where it would do a lot of good
V' 277 1 because of some arbitrary environmental conditions.
[~'} 2 As a matter of fact, as you know, people are moving
\,j 8 a lot of these instruments out to the ends of long lines where 4 the sensing capability has been badly degraded because 5 environmentai qualifications are set in.a very arbitrary way.
6 1 think from a practical standpoint it would be 7 desirable for the Staff to have that flexibility, but the 8 flavor of it is the thing you are talking about, and there is 9 a lot of marit in trying to phrase it in that way so that it 10 doesn't encourage people to make changes just because they 11 have got the opportunity to'do so.
12 MR. MICHELSON: What I would really like to see is p~s 13 what you suggest plus a few words to the effect that the Staff 14 is still looking at the failure of other than pipes to 15 determine what environmental effects it would have because 16 'there may still be far greater leaks possible than the 17 postulated detectable leak under this rule.
18 So i think the issue is far from closed by just 19 saying environmentally quellfled only for the leaks they 20 detect.
21 Mt . SIESS: If it is other pipes you are concerned 22 about, it is clear that won't change.
23 MA MICHELSON: Not other pipes s other conditions.
24 MR BUSH: Those have been looked at in considerable O)
(, 25 depth, and I don't know of any case -- for example, tops of
I 278 1
valves and things of that nature where they represent leakage
_( ) 2 greater than this because if we talk with, say, a 10 percent a upper bound on that, we looked'at that years ago with regard 4 .to zipper effects and so forth where you get a series of 5 failures, things of that nature.
6 MR. BOSNAK: I wouldn't be surprised in a few years 7 if we are talking about what we are going to do with new O plants when we looked at this whole area, instead of being 9 very mechanistic with respect to what is going to cause the 10 effect, you might be very proscriptive and say as far as the 11 environment is concerned, here is what you have to have to 12 qualify in inside containment.
[ i 13 I would see us perhaps going in that fashion.
\j 14 MR. SHElJMON : it seems to me when the Germans came 15 through with something about like this, or their removal of 16 this, they said you will postulate only a one-tenth 17 cross-section area fracture.
18 MR. BOSNAK: They still keep the whole area for 19 containment for equipment and for supports.
20 MR. BUSH: That was completely arbitrary too.
21 MR. BOSNAKt An arbitrary, non-mechanistic break.
22 MR. SHElJMON : Have you thought about something like 23 that saying there is no pipe whip, but instead of how many es 24 gallons will come out the size of some darned crack, just i
[G 25 saying we will reduce it by an order of magnitude and that is i
279 1 what they will design for?
O(/ 2 MR. BUSH: It was discussed at areat length.
8 MR. BOSNAK: We thought about it and we are still 4 thinking about it 5 MR. SIESS: I think what Carl Michelson's concern 6 is, and if I understand it right, I certainly share it, the 7 double-ended guillotine break has been accepted for many, many 8 things as an upper bound, as a result of which you didn't have 9 to check certain other things. If you assume the double-ended 10 guillotine break for equipment qualifications and so forth, 11 that was an upper bound and you didn't have to look at other 12 things.
( '
18 Once you remove that upper bound, you either have to
\s,
- 14 look at those individually or settle on something else as a 15 new upper bound, and I think this is the thing you have got to
! 16 wor ry about . .
17 MR. BOSNAK: Nobody disagrees with that.
18 MR. SIESS: The things we have been neglecting 19 because we were comfortable with this upper bound in this
, 20 particular area. What the rule ought to say is we have not 21 decided what the effect is on equipment qualification, or some r
- 22 word that gets equipment qualification in there.
23 MR. MICHELSON: Or and leaves it as it is.
24 MR. BOSNAK That is definiteIy the intent.
25 MR. SIESS: Let's don't leave it as it is, but that
280 1
1 l.t be done case by case, if necessary, because it may not make
[
2 a difference, 1
3 MR. BUSH Could I make a comment on a positive 4 aspect I don't think Bob has put up there? If he were to have 5 that diagram back on, if you were to look at the tech specs on 6 most of the plants now, you will find that all of those welds, 7 the nozzle welds, et cetera are exempted from inspection. You 8 can't get to them very straightforwardly. There is no way you 9 can inspect them.
10 Therefore, of the primary system, probably a third 11 of the welds you forget about because they are inaccessible, 12 and something I would see as a benefit --
not that i expect 13
( them to break, but you certainly would like to be able 14 to monitor things and see if anything is happening -- would be 15 that once this garbage is removed, we will have access, and 16 then, of course, it would revert to the required inspection.
17 MR. SIESS: Carl Arlotto had an answer, or a 18 question?
19 MR. ARLOTTOt I've got a comment. I think,
, 20 Mr. Chairman, the comments made, particularly by Carl 21 Michelson, and the concern of others, are well taken. I think 22 from a procedural viewpoint, I think it is time we recognize 23 that this is going to go out for comment. I think the
('
- 24 combination of the comments we get from the public, the 25 comments that we get from the committee, the things we have
281 l 1 heard now, will somehow make us write the final rule within f- s
, 2 the context of this particular discussion.
3 1 think the key item -- and Bob Bosnak has said it 4 several times -- is we are really pushing to get rid of the 5 piping restraints. We can do that by just saying we are not 6 going to be doubling the pipe breaks in the primary system of 7 pWRs. That will do us a great deal of good even if we 8 continue to say that the area for design, that is, the break 9 area for design were the same. Just eliminate the doubling of' 10 pipe breaks. You are not going to get the whip even if you 11 did get a split equivalent to that, which we don't see how you 12 can do it.
13 Secondly, I would like to observe that most of us
[a\
14 'who have talked to the Germans regarding the 10 percent break l 15 have concluded that it was a pretty arbitrary decision that 16 they have made. They do not seem to have the data to support i
i 17 that decision, and I think that we are now -- if I can now
! 18 combine the two offices, NRR and Research, we are now in the 19 process of looking at a research program associated with f 20 degraded piping, and hopefully perhaps we can put some meat on 21 the bones of fracture mechanics and come up with a definiti.ve 22 upper bound kind of a break, but right now we just aren't 23 there, i 24 But I think the stuff that we have been talking 25 about must be cleaned up, I think at the final rule stage.
.. - - . . --- . - _ ~ - .__ - - - _ . . . _
282 1 This part of'the process we are going through.
((h,) 2 MR. SIESS: I would have thought that 10 percent was 3 not a whole lot more arbitrary-than 100 percent.
4 Jesse, did you have a question?
5 MR. EBERSOLE: I remember back in the early BWR days 6 one of the more horrendous piping failures was to imagine a 7 vertical split in one of the risers that would create a steam 8 and v1por ejection process that would create a monster 9 centrifuge round and round the drywell and literally strip a 10 lot of the instrumentation off that was needed to mitigate the 11 consequences. You know, like the level columns, et cetera, et 12 cetera.
13 GE invoked the notion that they had 180 degree 14 equater logic, which has a flaw in it that you only loft half 15 the instruments. That didn't permit the random failure of the
\
16 first track to mitigate.
17 When you get into environmental qualification, what 18 l'm hearing is you are just about eliminating the dynamic 19 effects of jets on such equipment. You may permit, and 20 certainly the industry is likely to hop right on.it, the l 21 actual mounting of critical and sensitive equipment right on 22 the pipes they are monitoring, from which they are taking 23 their instrument taps, because you are eliminating the notion f
j , 24 of pipe bursts and just saying that pipes drip.
(
25 I can't get it quite through my head yet that pipes l
l l
l i 4
283 1 don't burst and they only drip, and that seems to be the way 4
( ,/ 2 you are going. Am I wrong?
3 MR. BOSNAK: Here again, we are talking about the 4 primary loop right now.
S' MR. EBERSOLE: I was, too.
6 MR. BOSNAK: I'm talking about a pWR. We haven't 7 gotten into the BWRs at all. And whether or not we are ever 8 going to be able to get through all of these situations here 9 with respect to loads, materials, what happens with respect t o' 10 aging of the material -- we started with something that we 11 thought we could be comfortable with.
12 MR. SIESS: Jesse, were you limiting yourself to 13 BWRs?
14 MR. EBERSOLE: No, I was being general, 15 MR. SIESS: 1 think desse was basically challenging 16 the --
17 MR. BOSNAK: The elimination of jet.
18 MR. SIESS: No, he is challenging leak before break.
19 MR. BUSH: He is challenging what I would call the 20 probabilistic fracture mechanics work, 21 MR. EBERSOLE: To the degree of leak.
22 MR. BUSH: That effectively would say in these t
- 28 systems you wouldn't have a problem. Now, you may not believe l
, 24 the numbers as such, but they are certainly very low number 25 MR. BENDER: I think i don't interpret desse as
284 i
1 saying quite what you are saying. I may be wrong in my (m, 2 understanding, it seems to me that what desse is suggesting
. 8 is that this new proposal should not be taken as a license to 4 locate equipment or instruments or anything else in an 5 environment where they might be threatened by some break like 6 this just because the relaxation gives you the opportunity.
7 MR. EBERSOLE: That is precisely what happens, 8 though, i
9 MR. BENDER: I understand that. All I am saying is 10 if there were some encouragement not to be too free with that 11 kind of action, you would probably be pretty happy, wealdn't 12 you?
13 MR. EBERSOLE:
( Yes, if I had some way to say, oh, he 14 didn't mount this transducer on the very pipe the fluids of 15 which he was monitoring.
16 MR. BOSNAK We do have that way..of doing it, and 1 17 know exactly what you are talking about because we were faced 18 with all of this when we had to get into what we called the 19 break exclusion region, if you recall, this was back in the 20 seventies when we started with the BWR because we couldn't 21 take the break in the region between the inside and outside 22 various containments. So we had this annular region we 23 couldn't. We then applied that same concept to pW9s.
24 MR. E9ERSOLE: You couldn't take it in the rim of 25 the fluid -- did you get rid of them?
285 1 --- -MR. BOSNAK: You couldn't take it because
()
\m / 2 . containment would be breached, and that was the basic reason,
~
3 but people started putting vital equipment in close to the 4 break exclusion region, and we then -- not because things 5 didn't break, but we didn't want those located there for fire 6 and other reasons. It is just bad engineering to not worry 7 about how your systems are arranged.
8 And we just can't permit anything like that.
9 MR. ETHERINGTONr if it's just on these structures 10 that are designed to resist the forces, it would be rather 11 bard to construe an instrument in this structure, wouldn't it?
12 MR. SIESS: Did you hear that, Bob?
() 13 MR. BOSNAK: I didn't hear your last words.
14 MR. SIESS: Say it again, Harold.
15 MR. ETHERINGTON: The rule is referring to 16 structures not being required to resist the jet forces s isn't 17 that correct?
18 MR. BOSNAKt That's correct. In other words, if the 19 Jet force is eliminated, the jet force is eliminated and you 20 don't have to deal with it.
21 MR. ETHERINGTON: lan't that structure used as 22 distinct --
l 23 MR. BOSNAK We are talking about structures -- in I
(g 24 some cases, of course, in the past, barriers were used.
V 25 shields to protect --
l-(
k
r- 1 286 l
1 _.. MR. SIESS: It doesn't include instruments. l 2 MR. ETHERINGTON: That couldn't include instruments 3 by any stretch of the imagination.
4 MR. BOSNAK: It was to protect vital pieces of 3 equipment generally, either other piping, valves, motors.
6 MR. ETHERINGTON: I see. So i n r etnov i ng the shield, 7 you are exposing instruments, that's correct.
8 MR. SIESS: Bob, if we commit ourselves to the pipa 9 whip restraints which you would like to get rid of because 10 they Impede inspection and a number of other' things, the 11 problem is relatively simple except that either the Staff or 12 the lawyers can't find a way to say don't put pipe whip 13 restraints in. They want to go back and change GOC-4 When 14 you get to the. jet impingement, which you have lumped'In now 15 with the pipe restraints, you open the door to this whole 16 question of environmental protection and the kind of thing 17 Harold has raised. A small break in the pipe might make a jet 18 that impinges on an instrument out there that would be just as 19 bad as what you have got with a full break, and how do you 20 take care of that?
21 MR. BOSNAK: The only way, as I say, if we eliminate 22 completely what we are talking about with enspect to primary 23 loop, if you believe in the fracture mechanics approach, that 24 we are not --
you know, we are going to get --
before we have 25 a jet that is damaging, we will have detection.
287 o<
a 1 _ , _ . MR. SIESS: That's your premise then.
2 MR. BOSNAK: That's the basic premise. We don't 3 have with respect to what we are doing right now a replacement 4 leakage' crack. There is work that is going on. As Guy 5 mentioned,- the Germans use this one-tenth area break. And one 6 of the items that is identified in Volume 5 of the piping 7 Review Committee Report is the development of replacement 8 leakage cracks. But we are not talking about the primary loop 9 news wo are talking about should this get into other systems.
10 MR SIESS: If you had a non-mechanistic arbitrary 11 10 percent break, that would give you a pretty good-sized-Jet, l
12 couldn't it?
['V } IS MR. BOSNAK: Actually, what we have now, we still 14 have all the branch lines, and of course, they are limited in l 15 their location, but they certainly give you the environment L 16 that you need. They are still there.
l
( 17 MR. SIESS: But your basic assumption, now, based on 18 the fracture mechanics studies, is that you will get a leak l
19 before a break that is large enough to produce a damaging jet, j 20 not just a leak before 100 percent guillotine break, la that i .
21 right?
22 MR. BOSNAK: That's correct.
23 NR. SIESS: There is leak before there is anything 24 more than just a few gallons per minute coming out somewhere.
25 MR. BOSNAK That's correct. But we still think
288 1 when we get into these other systems that we need to go
- / \
(_,) 2 further, tJe need to do some of the things you are talking 3 about.
4 MR. SIESS: I know, but that is being conservative.
5 MR. EBERSOLE: This will in turn permit you to mount 6 instruments on the pipes which they monitor.
7 MR. BOSNAK: I didn't hear what you said.
O MR. EBERSOLE: I said this will permit you to mount 9 relatively delicate instrumentation on the very fluid systems
- 10 that they are monitoring.
11 MR. BOSNAK: Again, I don't think that's good 12 engineering practice to do.
13 MR. EBERSOLE:
( Engineering practice i s wha teves- --
14 MR. BOSNAK: LJe have everything in place.
15 MR. SIESS: You are not changing good engineering 16 practice s you are changing a rule.
17 MR. RODABAUGH Bob, one of the breaks you are still 18 going to postulate will be that roughly 16-inch branch line, 19 which I think would be a tremendous amount of --
from this 20 very limited standpoint, it seems to me that your concerns are 21 ad' dressed.
22 MR. SIESS: A limited location.
23 MR. BOSNAK Limited location, but they are still i
f-- 24 there. They certainly do what the German 10 percent break k
25 does, definitely.
p 289 1 _.. MR. BENDER: I think you should at least pay
'n
' \_s 2' . attention to Mr. Arlotto's point. I think the message has 3 been presented and it seems to'me the Staff understands it, 4 and what they would like to do now, as I understand it, 5 primarily is to let the proposed rule go out for comment, have 6 the committee present its comments concerning the proposed 7' rule, which it will do anyhow, and let other people comment as 8 well 9 And then when the final rule comes out, at least my 10 interpretation is that there will be some conscious effort to 11 take account of the comments that have been made here. That's 12 what I thought he said.
13 MR. ETHERINGTON: Of course, the industry is not 14 likely to address the points that desse is raising. I mean 15 the comments that we will get back.
16 MR. EBERSOLE: I will give you an example. The 17 early designs of the break segregation system for the boiler 18 use numerous impulse lines to measure the transient pressure 19 gradients in the primary piping. They were strapped to the 20 pipe within which the gradients occurred. And thus, if a jet 21 effect or a break occurred, they were instantly destroyed.
22 MR. ETHERINGTON: In this particular case, would 23 that matter?
24 MR. EBERSOLE: Yes, it would destroy the transient
\.
25 gradient measurement that they made and you wouldn't know
290 1 which went. This was to swing the ECCS system to the right or rm
( )
.\ ,/ 2 left. So the accident itself destroyed the sensing apparatus, S which was intended to monitor.
4 MR. SIESS: Let me try to. summarize where i think we 5 are. If we accept leak before break, fracture mechanics, 6 probabilistic and so forth as being exceedingly low 7 probability, and the likelihood of being able to find the leak O before you have either a double-ended pipe break rupture or a M3 high enerav jet, the objective of the Staff is to eliminate '
10 massive -- as John called them --
evil pipe whio restraints 11 and presumably equally evil let impincoment devices.
12 1 think there is a feelina on the part of the
/
A
) 13 committee that the Staff may not have adequately considered 14 other consequences of a rule change which eliminates the 15 double-ended quillotine break, and thu implications to other 16 aspects of design. It accano l 6 ahes wha t vou set out tn do.
17 eliminate the evil structures, but whe t her- vou have thoucht 18 about other things that en i gh t be legativ cone under that same 19 rule may have not oaen thought of pr obab l v because vou think 20 further steps down f roen tne rule, Standard Review Plan, 21 whatever, and I uon't tnink we have a complete understandino 22 of what other r equ i rernun t s there are that would prevent these 23 secondary --
maybe not secondary, but other consequences of s 24 the rule change.
25 i think that is where we stand. The committee has
m 291 l' tAlsed several issues, environmental qualification, thinos k,
g 2 Jesse said which are sort of environmental but not quite. Do 3 you understand that position, Bob and Guy? We may get it in 4 writing eventually. But I haven't heard any real serious
- 5. challenges to the basic premise of leak before break in 6 the primary system of pressurized water reactors as a 7 Justification for eliminating these massive restraints, 8 although there may be some that haven't been completely 9 expressed.
10 if you understand that, I would suggest that we go 11 on to whatever the next step is.
12 MR. BOSNAK: The next one is the arbitrary 13 intermediate break.
14 MR. SIESS: Now, before you skip to that, the 15 broad-based rule involves all of these same considerations to 16 a higher power.
17 MR. BOSNAK: Broad-based rule would get into other 18 lines and all of their ramifications, it gets much more 19 complicated when you leave what I consider to be a system in 20 which we have bounds on all of this. When you start getting 21 into other areas, it is going to be much more difficult even 22 from just the application of fracture mechanicst'do we know 23 what the loads are, that certainty. So that is this 24 broad-based rule.
\
25 MR. MICHELSON: We are not discussing that today,
292 1 then, I guess, because there are a whole lot of questions if a
_- 2 we got into that.
3 Could I ask you one question, though, on the 4 fracture mechanics techniques? How does your confidence 5 change as the pipe diameters grow smaller? Ray?
6 MR. KLECKER: I'm Ray Klecker from NRR. I think the 7 problem when we get to smaller lines, the fracture mechanics 8 itself will be essentially the same. The technique is there.
.9 There is no change in the technology for that. The 10 difficulties probably will be in sizing a crack large enough 11 so that you can be assured of detection and still have that 12 crack smaller by a factor of 2 or whatever as compared to the i la critical crack size in that line.
14 For that reason, there may be a cut-off in the size 15 of the pipe that we go down to. Now, we are leaving this as 16 an option to industry. They do not have to postulate leak 17 before break. They can go back and leave their restraint 18 systems in on these small lines if they so choose, and some of 19 them indicated on some restraints they would do that.
20 MR. MICHELSON: Do you have a size in mind yet where 21 you think it begins to get shaky?
22 MR. KLECKERt Somewhere around 6 inches diameter.
23 MR. BUSH I could comment on the same one, s 24 There's an Adelphi technique that is currently on the way that 25 is looking at this whole business of what I call the
o ,
-293 1 pr_obability of break from the spectrum of sizes from about an l'
- k
.s _ 2 inch on up to'the maximum size of the systems. It is in the 8 second iteration, I guess. It'will go through probably one 4 more iteration. How much value it will have, I don't know, l 5 but it will certainly converge on some of these problems.
6 I think what you will see out of it is the 7 probabill' ties that are cited for small items would be 8 substantially higher. As far as breaks are concerned, they 9 would be larger.
10 MR. EBERSOLE: Do you have any notion what the 11 -variation is?
12 MR. BUSH: About ten orders of magnitude.
(.v - 18 MR. EBERSOLE: -Ten orders?
14 MR. BUSH: Sure. The probability on the big lines 15 is around 10 to the minus 11 On the really small lines, it's 16 more like 10 to the minus 1.
17 MR. SERPAN: Serpan from Research. On your 18 question, Mr. Michelson, the smaller the pipe, the better the 19 confidence we.have in the properties because that's the kind 20 of stuff that we test. We are testina 4, 6. 8 inch diameter 3-21 richt now and havina to extrapolate that to the laraer stuff.
PP So I think we know better what the properties and 28 characteristics are of the smaller ploe.
24 MR. MICHELSON: The defect. I think. was the real T,-w)s v
- P5 oroblem. wasn't it?
294 1
MR. SERpAN: We can orobablv find that easiar. tnn.
. ;/
~ ( /. P because it's coina to be thinner walled.
-3 MR. ETHERINGTON: Does the Staff have a minimum nina 4 size-for snubber reouirements, restraint reouirements?
0 5 MR. BOSNAK: No. You will see on some small lines 6 all kinds of things.
7 MR. ETHERINGTON: Small as what?
8 MR. BUSH: An inch to an inch and a half.
9 MR. ETHERINGTON: Doesn't<lt make sense to have -
10 snubbers on those thinas?
11 MR. BUSH: Don't ask me s I'm biased. '
12 MR. SIESS: You shouldn't ask that question,
( 13 Harold. Snubbers are not the same as whip restraints. Am i 14 right?
4 15 MR.~ BUSH: That's right. They are a different 16 animal. ,
17 MR. BOSNAK: Oh, yes, definitely.
, 18 MR. SIESS: Snubbers restrain the pipe in services i
19 whip only restrains it once it breaks.
20 MR. BOSNAK: Theoretically there in supposed t o .tne 21 no contact. That's one of our fears, that over the years 22 there will be contact between the whip restraint and the 23 pipe. There is not supposed to be any.
24 MR. SIESS: There are hundreds of snubbers on 1-1/2 25 inch pipe.
_ . - _ _ _ - _, - _ . _ _ _ _ _ _ _ _ . _ _ _ . . ._.. _ _ . - , . _ _ _ _ _ _ _ _ _ . _ . _ _ _ _ - - _ ~ _ . _ - -
295 1 __. Larry.
f%
)
hs/ 2 MR. SHAO: For the smaller lines, I would more worry 3 about the extended events. I think, for instance, this cannot 4 break a 20-inch but it may break a 2 or 3-inch line.
5 MR. SIESS: Let's go on to AIB.
6 MR. BOSNAK: Arbitrary intermediate breaks, to 7 refresh your memories, is a situation in which we have the 8 prescription for postulating pipe breaks. Certain stress 9 level, certain in the case of Class 1 lines that are evaluated 10 for fatigue, certain fatigue usage factor. Again, the usage 11 factor is one-tenth, and the Code, of course, permits you to 12 go as high as 1. So we have a factor of 10 there.
gs 13 g ) The stress value is 80 percent of what would G
14 normally be permitted for upset conditions. If you are below 15 those, you don't have to postulate breaks. If you have a 16 given line, you have two anchors in a line configuring however 17 it may, if you do not exceed the stress level or the fatigue 18 levels, you nonetheless have to postulate two breaks, and this 19 is in an area which has low stress and low fatigue usage 20 factors. You have to postulate two at whatever the highest 21 locations are, and these are termed arbitrary intermediate 22 breaks.
23 MR. SIESS: The location was not arbitrary?
24 MR. BOSNAK: Their location is whatever the highest
%J 25 value happens to be, and one of the problems, of course, that
296 1 keeps changing is as you reconfigure the piping system, you
-R r \
( j/ 2 never know where those break locations are going to be. I 3 have in your handout the slides that we presented to the 4 corimittee here in '83, but right after that, we started with 5 t>um first owner, and that happened to be Duke Power on
~6 Catawba, and we went through their systems and we at that 7 point in time said we are not going to permit this to take 8 place in those systems that are subject to large dynamic 9 loads. In other words, things like water hammer or steam 10 hammer where you have a mixing situation or a thermal fatiguo 11 kind of area.
12 Also on those lines that are susceptible to stress
()
v 18 corrosion cracking. So t hor.e three diseases, if you will. We 14 said if any of the systems are subject to those, don't ask for 15 elimination of arbitrarv intermediate breaks.
16 If you have l ooksed a t Volume 8 of the Ploino Review 17 Committee report, based on. I ouess, some of the work that 18 Livermore did as a consultant to the committom. it was dar.idad 14 that those caveats could be drocoed. But uo until the present Pn time, those caveats are still in place.
21 So when we went through the Duke Power Plant, the 22 feedwater system was not included.
29 Now, what is a trade-off that we get?
24 CSlide]
25 ,
This is on your handout. I wanted to point out this
297 1 particular one at the bottom, that when we eliminate the r
(_j/ ' 2 arbitrary intermediate breaks, we are saying you have to 8 environmentally qualify for the non-dynamic effects of 4 non-mechanistic break with the greatest consequences on the 5 equipment in that space, and, by the way, in all other 6 areas along that same line.
7 So we are getting more here from the point of view 8 of equipment qualification than we had before. Before, you 9 had two terminal and breaks, and you might have had two of 10 these arbitrary intermediate breaks located somewhere along 11 the line.
12 All along the rest of the area, you had whatever the (v 18 utility chose to give you in the way of equipment 14 qualification. So here we are getting more.
15 MR. SIESS: What are you eliminating? The whip 16 restraints?
17 MR. BOSNAK: We are eliminating the break. Whip 18 restraint, the whole business is eliminated. Whip restraint, 19- any jet impingement barriers. Essentially from the point of 20 view of what does it offer in the way of benefits, you get rid 21 of the > steel, you don't have to worry about loss of heat 22 because in these locations where you have pipe break locations 23 and you have whip restraints, the Insulation 6s generally not gg 24 configured as it is on the rest of the pipes, so you have heat 25 losses, it Impedes inspection, it does all of the things that L.
298 1 we spoke to you with respect to the large break.
- f. 2 Now, this is not based on fracture mechanics. It is a not based on any of those things but it is based on the fact 4 that we know we have low stress, low usage factor.
5 MR. SIESS: Bob, if I assume an arbitrary 6 intermediate break at point x on the pipe and put in the 7 appropriate jet impingement and pipe whip restraints, how does O the probability that the pipe would break at that point x 9 compare to the probability that it would break at a point five 10 feet away?
11 MR. BOSNAK: With all of these situations with 12 arbitrary intermediate breaks, the probability of breaks in 18 those locations we think are much lower, certainly, thansat
~"}
%J 14 terminal ends or at points where you have high usage factor or 15 high stress, 16 Again, the problem is that these, points during the 17 course of construction can shift 20, 30, 40 feet.
18 MR. SIESS: That's what I mean. You picked a 19 certain point due to pipe restraint, but if the break occurs 20 two feet away, the pipe will whip.
21 MR. BOSNAK You have no protection unless you 22 happen to have something with an elbow or something that might 23 be so configured, but that would be by coincidence only.
24 MR. SHAO: The probabilities in the intermediate O 25 break area are not that high.
299 1 , _ ,
MR. SIESS: My question was how does it vary along
/D
() -2 length.
3 MR. BOSNAK: If your stress and usage factors are 4 low, we think the probabilities of having a break at those 5 ' locations are a l so eq.Ja l l y low.
6 MH. SIESS: That's not the question. If it's low at 7 this point, I don't think it is that much lower at this point.
8 MR. BOSNAK: probably not.
9 MR. SIESS: I don't know what you get by putting - -
10 MR. BOSNAK: Not very much. That's why we think 11 this is more important than anything we give up In getting rid 12 of the pipe whip restraints. This is not involved in a rule
[ 13 change, but this will be involved in a change to the Standard
\
14 Review plan. So these have been processed as deviations to 15 the Standard Review plan.
16 MR. SIESS: How did you get into the arbitrary break 17 in the first place? You have got a 30-foot length of pipe, 10 say, and you assumed a break at each and of it where there was 19 an elbow or something. And now you feel that if you put in 20 pipe whip restraint somewhere in that 30-foot length, you are-21 going to reduce the probability of a pipe break. But you pick 2? one spot to put the restraint, and I don't see that you have 23 s reduced the probability 'ignificantly, gg 24 MR. SHAO: Let me give you some background --
\
'~'
]
25 MR. BO9NAK When It was made, it was made to try to L
300 r
1 get some degree of coverage, and not necessarily the whip
( s 2 coverage but environmental coverage.
3 MR. SIESS: You have taken care of that another way 4 now.
5 MR. BOSNAK We are taking care of that. Again, 6 people were designing --
7 MR. MICHELSON: How?
8 MR. SIESS: That last item.
9 MR. BOSNAK: people were designing in a very 10 mechanistic way. Unless there was a break there, they said, 11 don't tell me about its with the qualification, I don't have 12 to worry about it.
(~
t 13 MR. SIESS: Will you explain that las't item again?
(
14 MR. BOSNAK: Yes. That means, not only in this 15 place where 1 eliminated the break, if we are talking about a 16 compartment along the length of a p'pe, but throughout that 17 entire system, if you have any places in which you do not have le environmental qualification -- we are talking about the 19 nondynamic effects. So what we are saying is the pressure 20 that's there in the line, the temperature, and if you have to 21 worry about, if you are talking about liquid system, if you 22 have to worry about flooding, that's why we are trying to get 23 In the break with the greatest consequences if there are any f 24 with respect to release of the fluid that is contained in that U
25 process line, and that's what you have to consider with
1 301 l
1 respect to environmental qualification.
2 MR. SIESS: So except for jet Impingement and local 8 compartment pressure, the environmental qualification is not 4 changed from what it is now, not reduced.
5 MR. BOSNAK: It's not reduced, it's improved for 6 those areas in which you have nothing now.
7 MR. MICHELSON: You are saying that you must take an 8 arbitrary intermediate break from the viewpoint of 9 environmental qualification. -
10 MR. BOSNAK: If you want to put it that way, but 11 It's not mechanistic.
12 MR. MICHELSON: 1 don't find it that way. We have
(}
Q) 13 jumped suddenly from the primary loop, by the way, over into 14 the broad-gauge thing.
15 MR. BOSNAK Because one deals with fracture 16 mechanics, as I tried to explain yesterdays the other --
17 MR. MICHELSON: We are mixing them now. I thought 18 we weren't going to get into the broad-gauge discussion.
19 MR. SlESS: We are on the third column.
20 MR. BOSNAK: We got into because you asked.for it on 21 your agenda.
22 MR. SIESS: We are into the third column. We are 23 not talking about any rules now.
24 MR. B03NAK: It's not part of the rulemaking at 7s 6 i V 25 all. It's part of the piping Review Committee recommendation,
302 1 and that's why we want to report to you on it.
9
(, 2 MR. MICHELSON: Okay.
3 MR. BOSNAK: As far as the NTOLs, as far as OLs are 4 concerned, we have nobody that has asked for it. I'm sure Cps 5 would be interested in it.
6 MR. SHAO: Let me say something about arbitrarv 7 break, what was the original thinking. Suppose you have a O four feet expanse of pipino suppose the stresses are verv 9 low. You don't need any break.
10 The original thinking, I think is, suppose there is 11 a pipe break through the pipe, it can be many inches. So even 12 though the break location may not be rioht, you may have some
[~ } 13 bumper in there, some apparatus in there and you stop the pipe V
14 whipping around. So , it doesn't have to be at that right 15 location, but with certain stops, two stops anywhere, 40-foot, 16 50-foot pipe, it cannot whip around. That was the original 17 thinking for the piping break.
18 MR. SIESS: That's poor thinking. If you put the 19 Intermediate break in the middle of it, and it breaks just on 20 one side, the pipe on one side is restrained, and the other 21 pipe is free to whip as much as it wants.
22 MR. BUSH: I would remind the ACR8 about the only 28 time I have negative voted or tried to, it was on a 20-foot 1
-~ 24 straight section of pipe where the end loads were minimal and 25 there as an insistence that a dog house be put on the pipe.
l l
l l
303 1 T h_a t probability of that pipe breaking would be so small that
() 2 it would be infinitesimal. That is the same philosophy that 8 we are seeing in the arbitrary intermediate breaks.
4 You know, you have got a usage factor that is 5 extremely low, almost non-existent.
O MR. SIESS: I believe the ACRS approved exception on 7 arbitrary lead-in brooks on one of the OLs recently, didn't 8 they?
O MR. BOSNAK We talked about this. We t a lked about -
10 this two years ago, and I don't think anybody had ptoblems 11 with it. We talked about it before we pot into the first 12 plant. Catawba was the first one.
[}
\ ._)
s 18 MR. SIESS: At Nine Mlle -- didn't Nine Mlle ask for 14 it?
15 MR. BOSNAK: I'm sure they did. 1*Ve got a list 16 here.
17 MR. SIESS: What about Hope Creek?
18 MR. BOSNAKt I don't have Nine Mile on the list.
10 Byron Braidwood --
20 MR. SIESS: It was one of those.
21 MR. BOSNAKt it was Dyron-Draidwood, I believe.
22 This, by the way, we are applying --
and i probably should 28 mention that whether this is a "p" or a "B" doesn't make too
,s
- 24 much difference as far as we are concerned. The reason that I ( )
25 you see more ps la there was an aggressive owners group that L
304 1 was associated with pressurized water reactor, and they were
(
( ,) 2 interested in pooling their resources and developing a 3 position on the arbitrary intermediate break, so there are 4 more ps than there are Bs.
5 MR. EBERSOLE: Let me go to the opposite end of the 6 quality spectrum, the pressure spectrum, and just pick up the 7 surface water lines. I only need two of them as a minimum O requirement. What you are permitting here -- I could run them 9 parallel side by side and invoke the fact that I would never 10 get a break in one of them to scour away the earth-filled 11 supports of the other and produce a coordinated failure of 12 both because I would be dealing with dynamic effects of 13 failure. How would cause the designer --
x_
14 MR. BOSN4K Before we approve these things, we ask 15 our systems people to take a look and to look for 16 configuration, to look for a layout and to see if there is any 17 reason why there is a problem such as the kind that you have 18 spoken of.
19 MR. EBERBOLE: There would be dozens, hundreds.
20 MR. SIESS: Jesse, this is not a rule change now.
21 MR. EDERSOLE: I know.
1 22 MR. SIESS: This only changes the Staff practice.
l 2'd MR. BOSNAK Are there any more questions on this 1
24 column?
! %,/
l 25 MR. MICHELSON: Well, let me -- this dynamic effects I
L
305 1 business, now, relative to Jesse's question, if the water is 2 leaking out at a very high rate, is that a dynamic effect even 3 though there is no jet per se from the water system, for 4 instance, of any concern? But there is a flood problem.
5 MR. BOSNAK: Exactly.
6 MR. MICHELSON: la flooding a dynamic effect?
7 MR. BOSHAK I wouldn't look at flooding as a.
O dynamic effect.
9 MR. MICHELSON: I couldn't find the definition of '
10 dynamic effects.
11 MR. BOSNAK: Flooding is covered by this kind of 12 thing.
13 MR. SIESS: Carl, we are talking about one of the O~/
14 ' rules of the arbitrary intermediate break.
15 MR. MICHELSON: Yes, the arbitrary intermediate 16 break.
17 MR. GlESS: You are not going to find that anywhere.
18 MR. MICHELSON: Not yet. I was just wondering what 19 they will define as non-dynamic, and I thought Jesse's example 20 is a non-dynamic effect when the water floods and washes the 21 dirt away.
22 HR. EBERSOLE: 1 think it's kind of an ambiguous 23 mix.
24 MR. MICHELSON: Someday you would like to see some
\
25 definitions written down so vou know what thav are considerina L
306 4 1 o,r, n o t considering.
.G i \
( ,/ 2 MR. SIESS: No pipe whips on that pipe.
8 MR. MICHELSON: That's right.
4 MR. B03NAK They are not generally high enerav 5 lines, so you don't have those kinds of situations.
6 MR. EDERSOLE: You have a very beautiful competence 7 to scour the basic support system.
8 MR. SIESS: Those pipes don't come under the headina 9 of this issue, though. -
to MR. DUCH: Evon if they did, Jesse, I doi't see 11 where it would make any difference because we have more than 12 one example of 100 to 200 feet of pipe with no supports
()
V 13 whatsoever that are vibrating without breaking. So why would 14 removal of, say, ten feet of soll have any impact on adjacent 15 pipe?
16 MR. EBERSOLE If they would contain a support, it 17 would have none at all.
18 MR. BUSH: All I can say is I have a difficult time 19 visualizing a wash that would take away 300 or 400 feet of 20 soll, and even then I'm not sure because I'm aware of cases 21 where all the supports have been removed --
22 MR. EBERSOLE: It just swings across the cavern?
23 MR. BUSH It just vibrates back and forth. There 7~ 24 la one case it isn't applied and this did occur, it has k /
25 occurred in China. That is, if you attach the pipe to the
[
1 w________-__________--___
1 307 l 1 s.t.ructure and the structure falls down, the pipe falls down, k 2 too. If you put it on the side of a hill and the whole 3 hillside comes down, the pipe comes down, too. That's a 4- special case.
! 5 MR. EBERSOLE: I know of numerous cases where the 6 pipes are buried in earth-filled --
l l 7 MR. SIESS: I don't think that comes under the 8 heading of arbitrary intermediate breaks.
l 9 HR. EBERSOLE: I don't know. I guess not.
- 10 PW9. SIESS: It's something that needs to be looked 11 at.
12 MR. BOSNAK If we are ready and finished with the l
13 questions, I would like to kind of sum up where we are in l
14 flexible piping and things that we would like to see the 15 committee act favorably on, r
l 16 With respect to damping and the spectral shifting 17 that we talked about '/esterday, particularly the damping, 1 18 don't think we have one plant now under construction that has 19 not asked for the use of the improved damping, the PVRC 20 damping. In the Cook case --
several, and I think you saw l 21 from the slides yesterday they identified the plants that have 1
22 and have not.
23 HR. BUSHi If the committee hasn't seen that --
24 NR. SIESS: The implementation of that is via Reg l
~
25 Guide?
u
308 1 .. MR. BOSNAK: The implementation of that will
/ \
l 1
( ,/ 2 eventually be via change to Reg Guide, both 161 and 122. In 8 the meantime, we are handling it via a special request to use 4 the ASME Code cases.
5 MR. SIESS: Okay, because it's not a rule.
6 MR. BOSNAK It's not a rule.
7 MR. SIESS: Just a Staff acceptance.
8 MR. BOSNHK: In effect, it is basically covered by 9 our 50.55(A) and the ASME. If you will, that is the trail by
- 10 which we may --
11 MR. SIESS: Except damping factors have always been 12 in the Reg Guide.
[)
\_/
18 MR. BOSNAK Damping factors are in the Rea Guides.
14 MR, SIESS: Now there's a dampina factor in the 15 Code, you use that in preference to the Rea Guide.
16 MR. BOSNAKt in lieu of, and what we do is we ask 17 that they check to make sure there is adequate clearance, and 111 that because of the possible chanae in accelerations of the 19 lines, that any line-monitored aculpment is quellfled for 20 that. That goes back in the response to the utility to use 21 this particular set of change in damping values.
22 So we have damping and we have the spectral shift.
23 The OLs --
r^s 24 MR. ARLOTTO: Just to be sure, Bob, there may be x
25 some confusion. The damping is not in the Code yet, it is
?
I
. 309 l
1 strictly applicable in a Code case, and we endorse Code cases t
(~%
\ ,) 2 through Reg Guides. I want to be clear we are not looking for 3 any change in regulations associated with damping.
4 MR. SIESS: So unless it's 50.55(A), whether it's i 5 Code case or Reg Guide, it's still not regulation, it's a 1
6 Staff interpretation.
7 MR. ARLOTTO: Code cases we endorse through our Reg 8 Guides.
9 MR. SIESS: Reg Guides, not a regulation.
- 10 MR. ARLOTTO: Right.
11 MR. BOSNAKr As far as the OLs are concerned, a lot 12 of them wish to use this particular case. We have had
[ 't is inquiries, particularly from Commonwealth Edison, with respect
'D 14 to support improvement. In other words, removal. They want to 15 go in in particular systems that are difficult to get at and 16 difficult to maintain. Support improvement. Support 17 optimization. Getting rid of snubbers. This is how they 10 Intend to use this particular --
19 MR. SIESS: This means changes in the design?
20 MR. BOGNAK They will change their design, change 21 the piping system support scheme.
22 MR. SIEGG: And reanalyze.
23 MR. BOGNAK And reanalyze.
-s 24 MM. SIEGS: At the OL stage.
25 MR. DOSNAK These are OLs. I am down now in the
310 1 second batch. These are plants with OLs, so they would have
{
( ,) 2 to come in and modify their FSnR. That's what they have been 3 told.
4 MR. MICHELSON: Why would they want to do that?
ev 5 MR. 900N4K To get rid of all of the snubbers that 6 have been plaguing them with respect to maintenance, high 7 radiation exposure, change the supports, optimize their 8 supports.
9 MM. BUSH: Carlyle, in terms of exposure, if you put-10 value on man rem and so forth, you are probably talking of a 11 plant that is, say, at the NTOL stage or a new plant that is 12 in the OL stage of anything up to $10 million to $15 million
[ } 18 in savings, and that excluded the fact that if you get into
\_,/
14 the rat's nest of having to go through the tech spec 15 requirements on testing, if you find failed snubbers, then 16 your sample size increases and your time between testing 17 decreases, and you can be down to six weeks and you may have 10 to test half or two-thirds of your snubbers. That says you 19 are going to be down probably for an excessive outage. So 20 that doesn't include any costs of excessive down time, so you 21 pay a tremendous penalty sometimes.
22 MM. ROSNAK We believe the cost of doing this wile 29 pay for itself in a matter of just a few years, fs 24 MM. MICHELSON: I appreciatu what t he we vu e w.... e, w k'
25 undVubtedly involved on t he pr .enas*y . i du . Lul i .n.nh L,e i a
311 I payt of thu bus;..oss i . e.ws. . h. .w w. .ww t s e.u p...., ..v i i
A y' h 2 nece. a.*lI, I s ... . . d .s '
. ;iu p. . .... e :p 9.p..sw. . e 4 vwr. 6 .wwes 5 ti.i. ww.t 'w..wiliw i. .. i . h w w. . a.. ii. . a va.t uw L saving outside 4 at . . . i . . : .. .. . . i . ..J l . . . . .we.Gue .eeg wha t are the benefits of 3 . w...sv i..u t i . % .. vu.a.Gw vi containment compared with what we u ... i u r e t bu l os s esu .
< llH . DUGH: They have cone to mechanical snubbers, I a uvuld name several systems over the last two vaars. Quad 9 Cities is a good example. Dresden, where thev had a water -
10 hammer that was so trivial it didn't even trip the 11 Instrumentation, so they didn't know thev had it. Everv 12 enubber locked up on that system.
13
[~
(_s You now have rigid systems that won't handle thermal 14 expansion on thern, and it's quite possible under some 15 circumstances it could lead to failure in the piping because 16 of that one thing, and that's under a normal operating 17 condition, and that has been happening again and again and l 18 again, i
I 19 MR. MICHELSON: So you are balancing that potential 20 loss of fluid outside of containment versus --
l l 21 MM. BUSHi These are not for handling pipe breaks, f
22 you realize.
23 NR. M I CHEl. SON : They have something to do with 24 that. They cause a pipe break is, I think, what you are 7-~
(
25 saying.
- i. -
312 i
1 .. MM. BUSH: They could cause a pipe break, but their r~S x ,) a purpose really is seismic.
3 NM. MICHELSON: The other solution, of course, is to 4 fix the snubbers so they don't lock up.
5 MR. BUSH: Well, I will give you a 150-break 6 document, if you want, but as to the statistics on failure, it M
7 hasn't changed that much in the last couple of years.
8 MM. ERERSOLE: Don't the designs for these problems 9 show they are basically hydraulic, that they don't depend on '
10 gravity?
11 MM. SIESS: They have two choices, now, Jesse.
12 MR. BUSH: That has been sort of the puddle on the n
( 19 Iloor.
's-14 MH, EHERSOLE4 l'm talking about a cylinder which is 15 dead ended on the bottom.
16 MR. DU9Hi The hydraulic anubbers have about eight 17 or nine seals in them. The most common one to go is the 10 pop-in valve. It's still a problem. They still haven't 19 solved the leakage.
20 MM. EHEMSOLE: It's all gravity loss, isn't it?
El MM. SIESS: Jesse, if the hydraulle snubber falls, 22 then you have no seismic protection.
23 MM. HUSHf They just flap in the breeze.
24 MM. EDERSOLE: They fall in the context that they
(
\
25 lose fluid. Don't you have snubbers which have cylinders dead
313 1 ended at the bottom?
A s, 2 MR. BU9H: If they do. I'm not aware of them. I 3 looked at what I thought were all of the types.
, 4 NR. EBERSOLE: Then they have got a seal that is 5 capable of dealning by gravity.
6 MR. BUSH: A seal situation. They do have closed 7 reservoirs, if that is what you are talking about. The e reservoir is fine. The problem is the seals leak. You get a 9 leak in the seal --
10 MR. SIESS: There are a number of instances of 11 reservoirs being impotent.
12 MM. MICHELSON: What do we lose if we take out the
( 13 anubbers? What is the hazard now?
U 14 HR 803NAK 1 think if you reanalyze the piping 15 system, if you can get by with a rigid restraint there instead 16 of a snubber, so much the better. .
17 MM. MICHELSON: That's what you are proposing here,
.18 to do the reanalysis.
19 MR. BOSNAK Definitely they are going to do a 20 reanalysis to use the new damping, the GORC damping, and see 21 what they can eliminate.
22 MM . M I CH8fLSON : So I guess the not conclusion is 23 safe or safar without the snubbers.
fw- 24 MR. BUSH: On a probabilistic ground, I think it is k
25 safer because they are not effective against vibration, which s .
4 L
314 t
1 6s where they have been used. They are not effective against
(
(s ,) 2 the dynamic event. They do not work with water hammer. They 3 just tear up the wall. So you put them in for seismic event.
4 Well, if you have higher damping than the purpose of a 5 snubber, the value disappears. I don't say that you take all 6 anubbers out because you do need some snubbers, but you can 7 reduce maybe 50 to 90 percent.
8 So what you do is you have to reanalyze your system 9 and establish what you do. That's really the emphasis. "
10 MR. B03NAKi Or as I mentioned earlier, you might ce 11 able to gut by with a smaller snubber that is easier to 12 maintain, it is less difficult from the point of view of :
/ 13 uxposure and maintenance. That's what we understand.
O) 14 MM. S I E GF. But your cost-benefit study was based ;
15 entirely on man rom, wasn't it? You didn't try to evaluate z
16 the possibility of pipe breaks using thermal restraint.
17 MM. BODNAK That's correct. No. l 19 MM. MICHELSON: Man rem inside the containment that 19 1 was sure --
20 MM. SIESS: 1 might just mention for Carl's benefit 21 that several years ago we asked Diablo Canyon to assume that a 22 anubber had failed -- the probability was about 1 -- and to 23 look at the consequences in terms of risk, if you wish. They
- -- 24 assumed, first, that it failed locked, which then led to some
~
25 fairly high probability of a pipe break due to thermal i !
i I
\
315 1 1,a t c h , .They then assumed it failed unlocked, which meant O
\ ,j 2 in a seism,6c event the snubber would not be effective, 3 And, of course, the probability in terms of the 4 thermal event was tremendously higher because the thermal 5 movements are there all the time and the earthquake only 6 occurs every 200,000 years, whatever. And you have got 7 something in there for that low probability event that if it e doesn't work properly, they don't, it puts a much higher risk 9 on something else. -
10 HM. DOSNAK l'm up to the next column if there are 11 no further questions on that, the coupling of LOCA and SSE. I 12 think that was in your letter a few years ago, it was
[}
NJ 18 something that should go forward based on particularly the 14 probabillatic work that Livermore had done on the 15 situation-by-situation basis.
16 They had at that time, I think, completed 17 Westinghouse, and now they have completed Westinghouut, le Combustion and 84W and are working on GE, So that is the tg status of that.
20 HM, SICBS I think at the time we looked at that, El they had not completed their work on secondary failures due to 22 seismic. They had only gone as far as the primary failure.
l 23 Am I correct? I have seen the reports on the secondary 24 failurea.
(q) 25 HR. O'9 MIEN: What do you mean by primary --
l
c 316 i , , , MR. SIESS: A pipe breaking due to stress, a LOCA
/^N
(_,) 2 caused by an' earthquake and the normal stresses on the pipe, 3 not by a crane falling --
4 MR. BO3NAKt They completed the secondary work on 5 IJestinghouse plants at that t6me.
6 MR. SIESS4 That's right. I said I don't think the 7 committee reviewed that, the steam generator falling over.
8 HR. O'HRIEN: We presented that to you in 1990, and 9 twice we presented that to you -- '
10 MR. SIESS: To the full committee 7 t
11 HR. O'HRIEN: No, just to the subcommittee.
12 MR. SIESS: That's what I meant. The full committee
[ } 13 looked at the primary.
D' 14 MR. BOSNAK So right now the only request that we 15 have here on that is on operating plante, and they are the CE 16 plants.
17 In order to get free of A-2 or to complete the work is on A-2, they are not taking the leak-before-break approach 19 because they really didn't have to. The only area that they 20 had that was overstressed was in the area of reactor 21 Internals, and only slightly so, and if they decouple, that 22 < solves their problem.
28 MM. SIESS: How la this being handled within the
,- s 24 regulatory process?
25 MM. BO9NAKa Might now it's in ELD. We have asked
317 1 the legal staff whether or not there is a need to, because of p-k, m 2 the experience we had on ODC-4, whether there is a need to do 3 anything with respect to GDC-2,' and the tentative answer we 4 have gotten back is, no. we don't have to change SOC-2, we can 5 go forward just on the basis of the work that has been done 6 technically and not make a change to GOC-2.
7 NM. SIESS: What will you chan'ge?
e MM. 900NAKi The only thing that would probably have 9 to eventually be changed would be the Standard Moview plan, to 10 recognize the fact that this is no longer necessary as a valid 11 load combination. We don't have to combine LOCA and SSE.
12 Again, as the recommendation in the piping Moview Committee r
( 13 report -- I think it's in Volume 4, but also Volume 5. If
\_
14 that, when justified -- In other words, when the work has been 15 done -- we can go ahead and do that, and now it has been done 16 for the three plJM vendors, and GE le in process, 17 t1M . EBEMSOLE: IJill this permit, thane the redesigns 18 of the so-called ECCS system for LOCA mitigation to be l
19 non-seismic in character?
20 NM. 80SNAKt No.
l 21 MM. ENEMSOLE Why not?
l 22 MM. SIESS: it has nothing to do with the piping 25 systmes, f~s 24 NM. ENEMSOLKi You are saying you are not going to i
l k') ~
25 have a LOCA ==
]
318 1 , , , MM. BOSNAK We don't have to add the loads together (O ,/ 2 to design the system for both. We would still have to design 3 them for seismic, and if you had pipe breaks, you still would 4 have to design things for pipe break, but you don't have to 5 combine the two.
6 MM. ESERSOLEs it's not equipment that's highly 7 specialized. It's for a large LOCA mitigation, low pressure, e and if you don't have a LOCA coincident with an earthquake, it 9 seems the standard non-seismic design would serve the
- 10 purpose.
11 NM. 90SNAKr But you do have seismic loads, and i 12 couldn't conceive of this as being considered non-seismic, so
[ la you design it for the seismic load alone..
(_. '
14 MM. EDEHGOLEs it's lust standing on standhv. I'm 15 saylna.
16 MM. 90SNAK: I understand. .
17 MM. E9EMSOLE: its failure would be nothina if vou 18 didn't have a LOCA. -
19- HM. 903NRK: That might be something that possibiv 20 might be looked at, but currentiv, no. We are basicallv 21 talkinq about here, again -- this hannens to be A-2 for the 22 operating plants. There lan't any NTOL that has need for this 23 because once you have leak-before-break, it effectively is
-s 24 moot as far as the coupling is concerned.
Nj 25 HM, SIEGS Dob, I realize this la the Diping Review
319 1 Committee, but witI the LOCA/SSE load combination in the t%
) 2
~
f u t'are be applied to containment?
3 MR. DOBNnK: We haven't gotten into structures. That 4 is nn arua:that would have to be -- ,
4 5 ,
MR. ElEGS: This now applies only to piping 6 analysis? f 7 MR. DOSNAKt That's correct. That's all we are O talking about here.
9 MR. SIESS: The stress on the piping will be -
10 computed for the LOCA or.for the earthquake but not for the 11 two comb ined?
12 'NR. BOSNAK That's correct. By the way, the rest f~ 13 of the world has always been doing it this way. They never
\/
14 combinnd except with a few exceptions. The major counteles 15 have never combined LOCA and SSE for piping. Aaaln. we are 16 talking piping.
17 MR. SIESS: Further questions on that?
r le CNo response.3 19 MR. BOSNAK The last is the thing that Shou-Nien 20 talked about vesterday. I'm sure evervbody will eventuallv be 21 Interested in it. I should put a check there. But richt now 22 that is decouplina of OBE from GBE. The maior part as far 1
23 as pipina is concerned is we don't want the OBE to control the 24 des.lon. That'a what we are trying to avold.
('
25 NR. SICSS: That, again, is an lasue that will go 1
320 1 beyond piping, but you won't be finished with it.
. /~N l
N ,,) 2 MR. BOSNAK: probably one that will involve a rule 3 change, part 100.
4 MR. SIESS: It would be very difficult to invoke 5 that simply for piping.
6 MR. SHTWMON: If that goes, it would affect the 7 whole thing.
8 .194 . BOSNAK What we are trying to do is not to have 9 an OBE load combination control of the design. The Germans.
- 10 what they have done, and I think i mentioned yesterday, they 11 have just Jacked up the allowable limit for that load 12 combination. It said you could go a little blt higher, so la that way It doesn't control the design, if we start talking
(%J) 14 about changes in the way that the systems are analyzed, 15 whether seismic inertial load is a primary, what we do with 16 seismic anchor motion, then this becomes fairly important.
17 MR. SIESSr. And in other structures.
18 MR. BOSNAK: And in other structures. But right now 19 It la not something we have to deal with immediately.
20 MR. SIESS: How would that be implemented? That 21 would require a rule change.
22 MR. BOENAK: To part 100 and then all the various 23 Standard Review plans, both in the structures area and in the f'^g 24 mechanical area.
! 25 MR. SHAO: Two ways. One way, if you change the l
l l
I' L
m 321 1 r_atio~in both in both rule changes.
O).
\. , 2 The other way is just like the Germans do. If you 8 increase the allowable for OBE you don't have to do a rule 4 change.
5 MR. SIESS: That's a terrible way to do it because 6 you have got allowables for pipe and allowables for 7~ structures, you have got allowables for everything.
8 MR. SHAO: Right now the SSE allowable and the OBE 9 allowable are not the same.
10 MR. SIESS: No , for structures or anything else.
11 MR. SHAO: For structures and-piping. So all you 12 have to do is Jack up your allowable for OBE but not all the t
N 13 way to SSE.
14 MR. BOSNAK: That's what the Germans have done.
15 MR. SHAO: Yes, that's what the Germans do. And if 16 _that go through, you don't have to change the regulation, _you 17 change the allowable.
18 MR. SIESS: You also have to change the damper.
19 MR. SH4O: You change the damping. You also have
, 20 to chango the allowable stresses.
21 MR. SIESS: 'That's a patchwork way to do it.
22 MR. SHAO: It achieves the purpose.
23 MR'. , SHEWMON : Again, the philosophy of why the OBE 24 and SSE allowables are different in the first place.
'/~sh
- \j difherent 1
25 MR. SIESSi You can justify that on D
l'
322 1 pr,obabilities and get the same level of risk.
' (, 0) 2 MR. BOSNAK: Other than the pipina. Then the a question is how high should the OBE be. Should it be 4 something that plants should be able to ride through? All of 5 those philosophical things come to the fore.
6 MR. SIESS: We had it covered once by giving three t
7 different definitions of it, which didn't make a lot of sense.
. 8 MR. EBERSOLE: This first rule would not affect the-9 tributory pipings off the main loops, will it?
10 MR. BOSNAK: Which one are you talking about?
11 MR. EBERSOLE: The first one, the first column.
12 MR. BOSNAK: No. Acain, this slide -- this will
[ 'N 18 help.
Q_.
14 MR. EBERSOLE: So we will still have some --
15 MR. BOSNAK: Does not affect this line and the other 16 branch lines.
l 17 MR. EBERSOLE: So we will.still have some rather
. 18 rapid depressurizations to deal with.
r 20 MR. EBERSOLE: When.vou aet the second rule in 21 place,-those will ~ disappear.
12 2 MR. BOSNAK: That is orobablv the next sten.
i P3 to ao to these other lines.
l 3 24 MR. EBERSOLE: When you do that, there is coina to 25 be extremely far-reachina system 1.
m plications. For instance.
l i
323 1 vou can get rid of the diesels because vou can use slow-start gs k ,) 2 turbines. I just use a distant effect that it micht have.
3 You have comp l et e l y o l im i nat ed -f as t-s t ar t requirements.
4 MR. SIESS: They are not eliminatina the 5 double-ended break for LOC 4 calculations.
6 MR. BENDER: Some of those would be desiraule if 7 they could do it 8 MR. EBERSOLE: Yes, sure.
9 MR. BOSNAK: Since we are back on this again, to 10 summarize, it is a limited exemption for pWR loop. Equipment 11 qualification is not changed. The heavy component support
- 12. Integrity will be maintained per the letter, and the 13
[/}
N structural design has not changed.
14 MR. SIESS: He is talking about ECCS equipment.
15 MR. BOSNAK: That does not change. Containment 16 doesn't change.
17 MR. EBERSOLE: Say we are carrying a heavy burden on 18 fast starts and on diesels.
f 19 MR. SHEWMON: I think they are changing the tech 20 specs to where the number of those they need per year is-going 21 down.
22 MR. BUSH: I have been spending most of my time on 23 that problem, and they are modifying. They are doing just
- 24 exactly what you say, paul They are essentially minimizing (v\ 12 5 the number of fast starts, to a major degree, so in essence
324 1
they are trying to minimize what I would call the testing r%
2 phase of the diesels.
s -
3 MR. SIESS: That is not the point. The point to 4 realize, Jesse, is that this does not change the double-ended 5 pipe break, instantaneous double-ended pipe break as a basis 6 for designing the ECCS on the containment.
7 MR. EBERSOLE: I understand.
8 MR. SIESS: It only affects the design of the 9 piping.
'10 MR. MICHELSON: Of course, it's not fully logical 11 since we have now by fracture mechanics, et cetera proved that 12 we can't get these big breaks anyway. Now, the question is
( 18 V) why are we continuing to foster designs of ECCS when there 14 is no break to address?
15 MR. SIESS: What do you decide in the piping Review 16 Committee?
17 MR. MICHELSON: What bothers me is I would think 18 somewhere in NRR a. presentation could be made. Where are they 19 really heading? What do they see down the road, and how is 20 t h i s 'a _ s t ep in finally accomplishing some down-the-road l
21 objective? How far are they going to go in this business?
22 It's a mish-mash, it's very illogical.
23 MR. SIESS: I think if we really believe there can't gg 24 be a double-ended pipe break, there are lots of other l-25 improvements we can make in these systems.
l i
{.
I I
325 l
1 --
MR. MICHELSON: A lot of simplifications you can "N
\ 2 make, and why are we picking on one area now? I realize why, 3 because it's a very expensive area and it has lots of problems 4 with it, but where is it going to lead from here?
, 5 MR. SIESS: We are sort of going back, Carl See, 6 'the original idea of the double-ended break was a' bounding 7 assumption for the ECCS and a bounding assumption for the 8 containment. But we didn't stop there. Then they started 9 looking at that for asymmetric loads, internal loads, and 50 while it was a reasonable bounding assumption for the first 11 two -- and I put " reasonable" in quotes --
it had other 12 consequences that got to be almost ridiculous.
n '
( 13 So now that Staff is backing.up to where they were N
14 when they first invoked the. double-ended pipe break to size 15 the ECCS to containment, but in the process, they may have 16 raised the probabilistic issue that they ought to reconsider 17 the other two, and that is your point and I think it's a very 18 good one.
19 MR. MICHELSON: And are they doing-that?
20 MR. SH40: The original thinking of the double-ended 21 break is for ECCS, and it goes to everybody. They said, wel1, 22 you designed to continue for the ECCS. I want support for 23 the other nitty gritty of this particular pipe break. But gN, 24 that wasn't the original thinking.
25 MR. SIESS: Carl's point is, now that you have got
326 1 yourself convinced that you can't have a double-ended pipe
,rx (g,,eI 2 break, we ought to go back and rethink the other. Actually 3 the containment has been rathunk. They are looking at 4 containments now for severe accidents.
5 MR. SHEWMON: Are we ready to' hear about combination 6 of dynamic loads new?
7 MR. RODABAUGH: I wonder if I could clarify one 8 point with Bob before we break. In your report you talk about 9 decoupling the OBE from the SSE. Can you also say that you, 10 for some reason, do not want the OBE to control design, and 11 the word " design" is a kind of very broad term to me. If you 12 are going to adjust things so that the OBE never covers design 13 --
I mean never controls design -- excuse me -- why do you
^[))
14 have an OBE at all? Why not just design for the SSE?
15 MR. BOSNAK: That's a good question, and I think in 16 the discussions that might come up with respect to rule change 17 to Part 100, all of that could be certainly considered and 18 talked about. We don't have any answers to that right at the 19 present time, but it certainly will be considered.
20 MR. BUSH: In fact, the CEGB is trying to go that 21 very direction.
22 MR. SIESS: I cgree with it completely. There is no 28 safety reason for havina two levels of earthquakes. You could f 3; 24 have two criteria. One is stress and the other is 25 deformation. One is a pipe break or some break, and the other l
r
l 327 !
1 1 is something moves too fa".
-4
. _j 2 NR. BENDER: The earlier concept was based on 3 something somewhat broader than lust pipe breaks. Originally 4 the idea of the OBE was to have a criterion for survival 5 -without the need for re-establishing the adequacy of the 6 plant, and that, I think, just incidentally turned out to 7 establish some criteria for the piping.
8 MR. SIESS: I think~if we went back in history, we 9 could find about three or maybe four reasons fer having an
- 10 OBE. I know another reason that came from Newmark that had to 11 do with analysis and the criteria, and I think there are a 12 whole bunch of reasons, none of which I think are good.
[ IS MR. HOU: Maybe I can add something.
(s,)/ '
14 MR. SIESS: Let's save it till after the break 15 because we are going to talk about OBE and SSE. That comes 16 under Volume 4, doesn't it? Well, we have already covered 17 that.
18 MR. HOU: I will -just make a short statement. The 19 OBE and SSE issues have been intensively discussed in a task 20 group in seismic design. Now we know for safety reasons-21 there is no need for.two levels. However, to protect the 22 Investment, and also if there is an earthquake occurring and 23 we would like to restart it, fg 24 Now, the OBE level will protect that, be sure there
! ).
\d 25 is no deformation, no structure integrity impaired and
328 1 functi6ning impaired.
-s s_/ 2 MR. SH40: So we know when to shut down the plant.
8 MR. SIESS: I guarantee you if you have an OBE, you 4 'are going to shut down the plant and you are not going to 5 accept anybody's statement that it's okay to start it up until 6 you have completely inspected it.
7 We will take a ten-minute break.
8 ERecess.3 9 MR. SIESS: Okay, John, you have got the floor.
10 MR. O'BRIEN: This is going to be a discussion of-11 Volume 4 from the Piping Review Committee dealing with other 12 dynamic loads and load combinations.
,~
l la CSilde3 N ./
14 Here is my presentation outline.
15 ESlide3 16 This particular task group addressed a number of 17 sometimes disparate issues, such as event combinations, which 18 . deals with potential simultaneous occurrence of earthquakes 19 with pipe ruptures, as well as possibilities for earthquakes 20 combined with other events such as water hammer. This should-21 be a bullet here.
22 Response combinations deals primarily with 28 multiply-supported piping, and Shou talked about that very 24 briefly yesterday. That group did not deal with it. We did, 25 but our recommendations pertain to seismic design.
329 1 __ We have an effort as well dealing with dtress limits
- , +
l
(_)) 2' and dynamic allowables. Wat er hanner was considered and, 8 finally, piping. vibration loads.
4 CSlide]
5 Here is a list of people involved. We had Sid-6 Bersen from Bechtei and Don Landers from Teledyne, who were 7 our industry coordinators.
3 ESlide]
9 'The first recommendation for mechanical design on '
.10 the first question is mechanical design of what? We say for 11 mechanical design, decouple earthquake primary system 12 double-ended pipe rupture, and Volume 4 made that
[ T 13 recommendation only for Westinghouse and CE. But since~ the
.. V 14 publication of Volume 4, work has been completed on B&W, and 15 that falls also within the scope of the recommendation.
16 We also say decouple earthquake and pipe rupture 17 when you have technical evidence. The task group says the 18 technical evidence exists for the primary loop piping of the 19 three pWR vendors.
p 20 if you look at Volume 4, it says mechanical design 21 components.and their supports, nothing else. That means no
- 22. structures, it turns out the interpretation of this is if
[
28 you have a snubber placed on a steam generator for resisting g 24 LOCA effects, it still stays. That is the very large one. As I
25 Bob says, he plans to use this here for CE. It applies to l
330 1 r_qactor internals as well Bob Bosnak intends to apply that
/<~s'
' V) 2 recommendation to resolve the lIcensing program for alI CE S plants.
.4 The task group essentially said nothing new about 5 water hammer. We accepted the guidance from the resolution of 6- the task of USIA 1 We said that unanticipated water hammer, 7- for, instance, due to pumping into a voided line, or 8 water-steam reaction should not be part of the design basis.
9 This was discussed, debated, and the task group said, no, 3 10 accidental or unanticipated water hammers should not be 11 included in the design basis.
12 However, anticipated water hammer, as, for instance, im 13 from a safety relief discharge valve and other sources should 14 be continued to be designed combined with earthquake. I'm 15 into response combinations right now.
16 MR. SIESS: John, before you leave the first one, in 17 the first bullet the last sentence.says adequate-technical 18 evidence is presented. Now, that implies that that evidence 19 will be presented by the licensee or an owners group or a 20 vendor?
21 MR. O'BRIENi Yes.
22 MR. SIESS: The NRC plans to do only confirmatory 23 studies on it.
es 24 MR. O'BRIEN: Yes.
25 MR. SIESS: The burden is on them.
. _ . - . . . . - _ _ _ .-~= . - . _ _ - - _ . _ - . .-
L 1
- 331 1 MR. O'BRIEN
- Yes. '
-~ ?
l N1 I Ef).
-( 2 MR. SIESS: Okay. Thank you. Go ahead, 3 MR. O'BRIEN: Now we-are into what. is response 4 combinations. The present procedure, which was developed in 5 the seventies by people like Larry Shao'for dealing with 6 piping, which have multiple independent supports, is to 7 envelope the support Erom all the groups of supports, and you 8 use this for basis for design.
l 9 There is a new procedure. called the independent q
10 support motion response spectrum method. It is not really
~
11 new. It has been around for a long time but never really 12 accepted. The task group recommends this be allowed as an 13 option to'the present. It is very, very super-conservative.
14 You ask me what kind of conservatisms are we getting. How
-ti ~
15 about a factor of 807 That means 3000 percent over tho'best L 16 estimate response-in some cases in some. locations, and we can 17' shave that down to where the conservatisms are only 500 18 percent, which is~ an achievement. ,
-- 19 The method adopted by the Staff.was based on work 20 per. formed by Brookhaven National Laboratories but is not l
21 exactly the same as the recommendations by Brookhaven.
22 , ESlide]
r I
23 The Staff now will allow an SRS procedure for g .24 combining the dynamic and the pseudostatic components of 25 response. pseudostatic is the same as seismic motion. That l
. [....- . . - _ . , . . _ . , . _ . _ . , _ _ _ _ . . _ . - . _ . _ _ _ - . _ _ . _ . . . . _ .
332 1 ob_viously is a relaxment. By the way, that's used for fatigue
-g k 2 evaluation. There is a less conservative rule now-permitted 3 for the seismic anchor motion for response for the 4 pseudostatic component.
5 We have also introduced some greater realism for 6 dealing with high frequency mode so it doesn't affect it 7 either conservatively or nonconservatively because it depends 8 on particular cases.
9 One question that faces us regarding this last thing' 10 on multiply-supported piping is that if you implement this and 4
11 implement the higher damping values, you are really reducing 12 the margins of piping to one. I don't know what NRR is going i
18 to do about it, but Research is undertaking studies to find 14 out if you relax in every aspect of piping analytical methods, 15 you might result in no margins and that might not be 16 desirable. ,
17 MR. SIESS: You mean no margin at all or no margin 18 from that?
- l. 19 MR. O'BRIEN: No margin in the p'iping analysis. You 20 may have margin on the input to the piping, you may have-I 21 margins in the allowable stresses, but in the piping analysis, t
i 22 they come back close to 01.
23 MR. SHEWMON: Are you saying ,i f you take the higher i-
! 24 damping values, then you and up with that?
l O 25 MR. O'BRIEN: The higher damping is best estimate l
333 1 damping, and now we are approaching best estimate analysis 75
's )\ 2 procedures.
3 MR. SHEWMON: Let me point out best estimate damping ,
4 is still not anything, giving any elastic -- any plastic 5 credit for the behavior of the pipe, since you don't build it 4
6 out of glass but, indeed, out of fairly tough stuff. There is 7 now a whole-realm of things which another part of this report 8 says we don't know how to do, take any credit for it yet or 9 use it in any analysis, but it is there.
10 MR. O'BRIEN: What you say is true insofar as the 11 piping integrity itself is concerned, but if you are talking 12 about functional failure modes, then it might not be true, and
/~~
13 this was.the issue that Mr. Michelson raised yesterday. If
[d) 14 you have got pumps and valves and other things like nozzles, 15 that might not be true. You might not be able_to achieve very, 16 very high damping before you will achieve some other kind of 17 failure mode other than the rupture or leaking of the pipe 18 itself.
19 MR. SHEWMON: It's not at all clear you will, but i 20 agree it's not clear you won't from what I know.
21 MR. SIESS: Which bullet are you on now?
22 MR. O'BRIEN: I am just starting this one now. I 23 finished this one.
fg 24 MR. SIESS: When you are talking about zero margin,
'~'
25 you are talking about which one?
334 1
MR. O'BRIEN: It's the top bullet here, which began O)
(, 2 on the previous slide.
S MR. SIESS: Okay. Now, let me get clear. There are 4 three kinds of margins. There is a margin in the assumed 5 input, there are margins that we introduce in the analysis.
6 and then there are margins we impose in terms of the 7 allowable, the ratio calculated stress to some allowable. Are 8 you talking about the bottom line or are you talking about the 9 analysis part only?
10 NR. O'BRIEN: Yes.
11 MR. SIESS. Because this is not objectionable from m 12 point of view. This is the way we do structural analysis. We
[}
V 18 put some margin on our loadings, we make the anslyses as good 14 as we can to be realistic and understand what is happening, 15 and then we put some margin on our stresses. I certainly have 16 no problem with an analysis being best estimate.
17 MR. O'BRIEN: Best estimate means 50 percent chance 18 of achieving the calculated responses?
19 MR. SIESS: I'll take care of that uncertainty in 20 my loading and my allowable stresses, but I want to do an 21 analysis as close as I can to the truth. I don't want'to be f
22 dealing with something that is acting differently than what i 23 .think the structure is acting. That's just a personal 24 philosophy, but it's one embodied in a lot of structural codes O 25 that I deal with.
-. - _ - . . . . .~ . . . . . . . .-
335 1 __ MR. O'BRIEN: Now we are down to stress limits and
-es s
,,) 2 'dy'namic allowables, and this is actually consistent with what 3 Shou said but is distinct from what he said. Our task group 4 said ~ that we do not wish a major shift to inelastic analysis 5 of piping systems using strain limits, and Shou Hou and his 6 test group advocated that performance for inelastic analysis.
7 should be established.
8 We allow inelastic piping analysis on a case-by-case ,
l
- 9. basis, and the reason that the task group made this
- 10 recommendation is we would first have to benchmark inelastic 11 ' codes, although there has been some limited amount of that
.12 .done. In addition, in order to apply general strength 13 criteria for inelastic analysis, our task group felt that 14 . strain limits that would result in a uniform' margin of safety 15 would first have to be developed, and this does not exist 16 right now.
17 So actually, we are actually consistent with what 18 _ Shou Hou said yesterday. He goes.beyond this and says take 19 the step of developing these strain limits. We say you can't 20_ 'do it now because these strain limits, wh i ch- g ive us . a marg in 21 of saf e t y,- don't exist.
22 Then-a very minor' thing is the present Standard
'23 Review Plan only allows a 10 percent increase to strain rate f
.24 effects, and we said in our task group that you should allow
(
25 more than a 10 perc'ent increase in the design, only of pipe
4 336 1 whip restraints, by the way, which in another group advocated
,m
( \
(,,/ 2 you remove, but some of them won't be removed. Some will 3 stay, and those you can redesign using higher allowable.
4 So that takes care of that aspect.
, f
- 5 MR. SIESS: You mean the restraint itself. You can 6 .take more than 10 percent strain rate effects.
7 MR. O'BRIEN: Yes. Right now it is limited --
for G pipe whip restraints, you can increase the allowable stresses 9 by 10 percent to account for strain rate effects.
10 MR. SIESS: Just arbitrarily?
11 MR. O'BRIEN: Isn't that right? Arbitrarily. But i f 12 you can justify more than 10 percent by test data -- usually r
ig)
( 13 test data -- then you should be able to use that beyond the' 14 present limitation of 10 percent.
15 MR. SIESS: The strain rate is some function of 16 excitation frequency, isn't it? -
17 MR. O'BRIEN: This is impact.
18 MR. SIESS: This is whip restraints. I'm sorry.
19 MR. EBERSOLE: I wonder. If you would clarify 20 something for me. I'm not at the structural and of it, but
, 21 this business of not having any reliable limits on strain 22 l iim i t s , if you have'a load which diminishes strain increases 23 to the limit of known importance, can you invoke other 24 strains? I'm talking about an elastic load, like a pressure,
, V t 25 just physical load, in which the deformation eliminates the
.y- - --.a - g - n r----- p -
_. _ _ _ . _ _ _ _ _ ._ __. . _ _ _ _ _ _ . ..m__ . .
- 337 1 further stress loading. Do you then invoke those kind of s/ 2 allowances? The material stretches i nelastically but the load a disappears at the end of that strain.
4 MR. SIESS: I think his point was he can't develop a 5 consistent set of limits to provide a consistent margin of 6 safety.
7 MR. EBERSOLE: That's for continued stress.
8 MR. SIESS: Any inelastic behavior, to try to~get.a 9 consistent set. We know what is there. He is talking about '
10 trying to get Code-type limits that will make some sense.
11 MR. EBERSOLE: For consistent stress.
12 MR. O'BRIEN: What we say i s uniform margin of n
./
) 13 safety, but it's the same thing.
. %)
14 MR SIESS: Uniform margin of safety. You know-15 what's there, but how do you take into account design and get 16 some results that don't vary all over the place, which assumes
, 17 that what we get now don't vary all over the place.
18 MR. O'BRIEN: On water hammer, these three bullets 19 are essentially consistent with the Staff Resolution A-1. We 20 recommend that rather than desian for water hammer, vou trv to 21 minimize or reduce the incidence of water hammer, with 22 emphasis on operator training, although you can do things like 23 jockey pumps and J-tubes as well
-s 24 The next two bullets reflect the Staff's G '
25 unwillingness to stick its neck out. We say that the
- , . - , , . . - , - . - _w, ,, - - . , _ . _m - - ,
r 338 1 development of design standards for water hanner should rest
,3
/ \
( ,/- 2 with the plant owner or applicant and his designer and not 3 with the NRC. This then gives us a non-uniform way of dealing 4 with water hammer because we say the NRC will not establish 5 standards for spec i f i ed wa ter hanner . We are going to pass 6 the responsibility to applicants. Some applicants are tough 7 on themselves and some are not.
8 The difficulty, of course, is how do you define 9 water hammer? Nobody knows how piping responds to water 10 hammer, either.
11 tJe even shied away from putting forth a checklist, 12 standard checkilst. There is a lot of pressure. Our
'{
%7 13 consultant, John Stevenson, pushed very hard for this. We 14 declined to do it because, as we say, there are a variety of 15 plant designs and operations that work against such 16 development.
17 Essentially the second and third bullets are just 18 pushing the responsibility to the applicant.
19 MR, SIESS: Mike has a question.
^20 MR. BENDER: I don't understand the logic of the 21 Staff's position.
22 MR. SIESS: A little closer to the microphone.
23 MR. BENDER: I don't understand the logic of the f ,s 24 Staff's position concerning this matter. It seems to me the (U
i 25 very lack of any basis for designing for water hammer is why
4 339 1 you can't have any confidence that you can protect against
/~T k) 2 it. If you allow every applicant to make his own judgment, 8 and, as you polni ed out just now, there is a spectrum of 4 attitudes. There is not going to be any way to have any 5 confidence that it has been dealt with adequately.
6 It seems to me that John Stevenson's suggestion of 7 at last a checklist to be provided was a pretty good one. Is 3 there any reason why the Staff backed away? Is it cowardly?
9 ELaughter] -
10 is it afraid of what it will find?
11 MR. O'BRIEN: It is not logic,-it's emotion.
12 MR. BENDER: All right, I won't say any more.
[~ IS MR. SIESS: John, do you have any idea whether
~d 14 designers have checklists?
15 MR. O'BRIEN: Yes, there are checklists available, u .
16 but there is no standard one. Actually, it tends to be the 17 AEs that prepare these standards.
18 MR. ETHERINGTON: I thought the problem was not in 19 the design but in knowing where the hammer load is going to 20 be.
21 MR. O'BRIEN: That's a major problem, postulating 22 water hammers as well as predicting the ductile piping 23 responding to it, particularly fluid ductile piping.
-s 24 MR. SIESS: John, your first bullet says the way to 25 handle it is to learn by experience, when you have water
~ - - , - - --
e - -- - - -_
340 1 h.a.m m e r s , revise your procedures, put in J-tubes, jockey pumps (m
,, 2 or whatever. Of course, that's what we have been doing now 3 for 15 years or so. Have we ever had a water hammer that 4 caused an accident?
5 MR. O'BRIEN: Oh, yes. Maine Yankee. We had one, a 6 cracked pipe.
7 MR. SIESS: I know we had a cracked pipe.
8 MR. O'BRIEN: No, not a radioactive release. Indian 4
9 . Point, of course, was a water hammer, i
10 MR. SIESS: So it is liplied m in the first bullet on 11 the basis of experience that water hammers have been such that 12 they don't lead to -- they don't endanger the health and 13 safety of the public, and then we can learn a lesson from them 14 and fix them. That is the implication i get from you, is
- 15. that what you mean?
16 MR. O'BRIEN: Yes, partly. part of the problem is 17 water hammers are very likely during other transient 18 conditions like an earthquake and a water hammer. That's a 19 very high probability because you can have a terrible trip, a 20 reactor trip, all kind of transients going on. Your. operators 21 are going to see a water hammer, going to get excited. The 22 human factor enters into it. So you have said - people 23 sitting at this table have said water hammers are probably gs 24 -more threatening than earthquakes, and we --
A 25 MR. SIESS: probably more frequent than earthquakes.
341 1 . _ _ _ MR .- O'BRIEN: We get seven or eight accidental, f3 s,) 2 unanticipated, seven or eight water hammers a year, whereas we
)
l S. don't get earthquakes at all.
4 M R .. SIESS: You cited safety valve blowdown as 5 anticipated. Are there any other examples?
4 6 MR. O'BRIEN: Well,-due to turbine trips -- where's 7 my list?
8 MR. SIESS: I know we had one'from stop valves 9' closing, that ripped out-a lot of pipe restraints, but it
- 10 didn't fall the pipe.
i 11 MR. O'BRIEN: There are a few other anticipated 12 transients.-- water hammers, I maar Turbine trips, vibratory
[ 13 loads. I guess SRV discharge and turbine trips are the 14 two primary causes of' anticipated water hammers.
15 MR. EBERSOLE: HPCI at Browns Ferry.was knocked off l 16 its foundations because it was called to automatic response
, 17 from a malaligned position, 10-foot level water heads.
18 MR. BUSH: That's a water soaking problem.
19 MR. MICHELSON: That was unanticipated, of course.
20 That wasn't anticipated. You can figure out it can happen.
21 MR. E8ERSOLE: Many of them are.
22- MR. MICHELSON: I think you can figure there is a 28 real serious water hammer involved in the steam condenser mode 1 f-~ 24 on the RHR heat exchangers on boiling water reactors. We are l
\ 25 looking into that a little bit now. I have got one of the
342 1 fellows doing some research on it. It's an interesting
. f)
- ( ). 2 history on how the-industry is viewing water hammers, or not 3 viewing them, depending on the particular utility.
4 MR. SIESS: And awful lot of the water hanners are 5 going to affect the reliability of the plant. Has anybody 6 done any kind of a risk analysis on water hammers? There have 7 been enough of them now that you can factor them into a pRA.
8 MR. O'BRIEN: Lots of them.
9 MR. SIESS: Will they tell us about risk of water 10 hammer?
11 MR. BUSH: The big problem there is --
12 MR. SIESS: I'm just going to say assume it f'} 18 happens. What does it do to risk?
%)
14 MR. MICHELSON: The RHR is an interesting one, 15 because, depending on where the wa ter hanner is occurring, it 16 might affect the operation of a single valve between it and 17 the primary system, in which it could blow down outside the 18 containment.
19 MR. SIESSr Has anybody done the risk assessment 20 that says what type --
21 MR. MICHELSON: Not as far as we can find so far, 22 but we are looking for one.
23 MR. SIESS: The Staff position presented here is-7- 24 essentially, we will just.take them as they come and fix 25 them. And what is that, restitution or something? And, alven
343 1 enough time, we will have the frequency down to a low enouch n
k ,) 2 level, assuming it isn't already that low. >
3 MR. BUSH: I think John said this pretty much 4 represents the position generated with regard to revolution of 5 the water-pressure, with which I didn't agree, incidentally.
6 in fact, I had a few sessions with the persons concerned.
7 MR. SIESS: This is saying,' don't change what we are 8 doing now.
9 MR. BUSH: That's pretty much what it comes down 10 to.
11 MR. SIESS: The first one says, when you have one, 12 try to do something to fix it.
/ \ 13 MR. SHEWHON It is known as benign neglect, isn't 14 it?
15 MR. SIESS: It is neglect, but --
16 MR. MICHELSON: Unfortunately, the history shows 17 some of these utilities have been having, like on the RHR 18 system condensing mode, one utility has had these happening 19 for over two years.
20 MR. SIESS: And hadn't fixed them.
21 MR. MICHELSON: It was tearing out supports, it was 22 doing a lot of serious damage, and finally just decided they 23 couldn't handle that mode of operation, and apparently are l' 24 . abandoning that mode of operation.
(ql
\_/
25 MR. SIESS: They couldn't fix it.
l aa
1 1
344 i
l 1 ___ MR. MICHELSON: Because they didn't know how to fix i
(~~h
\ ,) 2 them. But yet GESSAR 11, for instance, proposes such a '
S system.
4 MR. ETHERINGTON: Yet GE has never admitted a 5 problem there.
6 MR. MICHELSON: I understand that may or may not be 4
7 the case officially --
8 MR. ETHERINGTON: The question was raised years ago 9 and nothing was done about it.
10 MR. SIESS: I guess the conclusion is a research 11 effort, say of the magnitude of the source term research 12 wouldn't solve a water hammer problem. That you couldn't g
18 martial enough national labs and computer codes to be able to 14 design for water hanners.
15 MR. O'BRIEN: If you are thinking of water hammer by 16 ,itself, it is hard to envision a core melt or any serious 17 radioactive release, because it is a kind of local event. It 18 is isolated to one piping.
19 The real concern is water hanner wi th someth i ng that 20 is not local like an earthouake. Or, lots of water hammers 21 aoing on simultaneousiv, due to a common source.
22 MR. SIESS: If I have got to combine water hammer 23 and earthquake to get in trouble, I am going to put it back on eN 24 the shelf a ways. But you said, you know, that you couldn't 25 do it analytically. You didn't know how to design for water
r 1 345 1 hanner . And my question was, if you want to spend enough
/
)(D),
2 money, could you learn how, or do you just think it is not 3 worth spending the money?
4 MR. O'BRIEN: You are going to see, we have a 5 recommendation for research on water hanner in a few minutes.
6 MR. SIESS: But not at the level of severe accident 7 research?
8 MR. O'BRIEN: No.
9 MR. BUSH: Chet, one problem here is that the energy 10 that a water hammer typically generates, the type we are 11 talking about, is usually a very, very small fraction, perhaps 12 one percent or less than ten percent of the theoretical.
/-m \
( 13 If you start analyzing on the basis of the
\
14 theoretical water hanner, then you know you are in trouble 15 because things pretty much tear apart in a hurry.
16 in fossil plants, they occur, I would say with 17 reasonable frequency, and it is a rather dramatic event, if 18 you see what a water hammer will do, say, to a cast iron 19 valve. If you want to see how shrapnel is generated in short 20 order, that is one way to find out, because you can generate 21 it in'a hurry.
22 The big problem -- and this has been looked at off 23 and on for about thirty years -- is how do you handle the g-s, 24 probability that you can have energies --
you get into that 90 25 percent theoretical r vibration loads.
u
346 a
1 _. The first bullet there is really an attempt to s
q, 2 account for gaps in piping vibration loads. Usually small 3 amplitude, high frequency. Those that are transmitted to 4 piping. presently they are analyzed by assuming linear
. l 5 analysis. But, you can find out that usually pipe support 6 gaps are not even closed, and the pipe doesn't even move when 7 the vibration is going on.
O This bullet will allow a less conservative way of 9 dealing with pipe vibration loads. -
10 (Slide) 11 And than we have scme vibration loads.
12 The first bullet there is really an attempt to l' '
13
, account for capc in piping vibration loads. Usually small
\
to ' amplitude, high frugaency. Those that are transmitted to 15 piping. prosently they are analyzed by assuming linear 13 analysis. But, you can find out that usually pipe support 17 gaps are not even closed, and the pipe doesn't even move when 18 the vibration is going on.
19 This bullet will allow a less conservative way of 20 dealing with pipe vibration loads.
21 (Slide) 22 And then we have some recommendations here..The 23 first bullet here is really consistent with present NRC gs 24 policy, and this ANSI /ASME standard is just a convenient E
)'
25 document for us to cite for the industry to follow.
- __,___,%.g y __
_3 y ., a v-- . , m,
. --ww--g -,y-
- . - . - . . _ ~ - - . . _ _ - . _ - . ..
t 347 n,
1 .. ,
That bullet is consistent with the way we are doing jq 2 business now.
3 MR. MICHELSON: Excuse me, on that bullet, does that 4 particular document require that the flow rates be varied so 5 that you have particular rates at which the vibration peaks' 6 out and so.forth?
7 MR. O'BRIEN: I don't know.
8 MR. MICHELSON: I don't either. Maybe Dr. Bush 9 knows?
- 10 MR. BUSH: I don't recall it as there. But, 1-11 confess --
is Guy still here?
12 Guy, you probably looked at this OM-S. But, as far
[d T 13 as I know, a significant factor with this one is that the' code 14 really hasn't discussed it.
In other words, it isn't-
'1 5 incorporated in either 11 or S. And, as a result, it is' kind 16 of sitting in limbo. Nobody is using it because there is no 17 force to use it, 10 MR. filCHELSON: l'have witnessed the operation of 19 systems which worked fine at full flow. You throttle down a
- 20. little bit and they will shake apart.
21 I wondered 'sf they had to run the range looking for 22 v i br a t i on '. So, it is not the kind of an answer --
23 MR. SIESS: Bob's got something to say. Maybe it is-p3- 24 an answer.
25 MR, BOSNAK: l'm not sure that it speaks to flow.
348 1 lphat the Staff had been using before the advent of this ln )
.t j 2 document was the vibration amplitude at 10 to the 6th cycles.
3 We have taken 50 percent of that.
4 This goes on and goes up into the higher frequency.
5 But I don't know that it contains anything with rospect to 6 flow conditions.
7 MR. MICHELSON: But it is supposed to address O fluid-induced vibration?
9 MR. BOSNAK: Fluid-Induced vibration. probably 10 assumes that it is operating in its usual operating mode.
11 And, if there is a mode which is worse, then that would-be 12 considered. But they really don't know.
/
) ~13 MR. SIESS: Carl is talking low-cycle fatigue, and 14 you are talking h!gh cycle.
15 MR. BCSNAK: Exactly.
16 MR. MICHELSON: Low-cycle fatigue is the concern on 17 fluid-induced vibration. You can see it at certain flow 18 rates.
19 MR. BOSNAK: But this is a high-cycle fatigue 20 standard.
21 MR. BUSH: Yes.
22 MR. O'BRIEN: The middle bullet on this slide is 23 just polishing up the Standard Review Plan to make explicit fs 24 reference to reciprocating eroding rotating equipment which 25 is not explicitly referred to. It is just a clarification --
1 F
349 l
1 __ The last bullet is really a push to depend more on 7
l \q,j 2 testing because analysis, we know, tend to overstate the a situation with regard to arbitrary loads. And this is born 4 from tests we have done at Koshane.
5 So, the recommendation - the' interpretation of this 6 last bullet is if you depend on testing, you will cet some 7 release, because the analyses is very conservative.
8 MR. SHEWMON: John, before you leave that, at least 9 three or four years ago, the code apparently quite at 10 to '
10 the 6th cycles on its fatigue curve and didn't go on. Yet, 11 things were failing at 10 to the 7th. They were allowed to 12 take the same level on out.
13 I remember a Japanese engineer asked me what we v
14 were doing about that.
15 Do you know.if there is data on what is to be used 16 beyond to to the 6th. cycles?
17 MR. BOSNAK: Austenitic materials go beyond 10 to 18 the 6th cycles now. It goes 10 to the 11th.
19 .MR. SHEWMON The curve does.
20' MR. BOSNAK: The curve does.
21 MR. SHEWMON: That's an improvement over three or 22 four years ago.
23 MR. BOSNAK: That's correct.
24 MR. SHAO: Anything more than 10 to the-6th or 7th
?
25 is. Some people use endurance limits.
350 1
MR.'SHEWMON: There is no endurance limit in
.[~%. *
'( j 2 'austenitic material.
3 'MR. SIESS: John, going back to the previous one, 4 the last bullet says " loads transmitted by supporting 5 structure."
6 is that seismic?
7 MR. O'ORIEN: No. This bullet is under piping 8 vibration loads, and it-really means SRU discharge.
9 MR. SIESS: Oh, okay.
10 MR. O'BRIEN: This task group doesn't deal directly 11 with seismic.
12 MR. BUSH: paul, 1 would indicate this was an NRC
[ 'T 13- decision. Or at least it was a part of an NRC task force in NY 14 ferritic materials, where a requirement was established that 15 you would have to operate to 10 to the 7th cycles. This 16 happened to be a diesel generator. But,.you know the analogy 17 is so extrapolatable on the basis that at 10 to the 7th, if 18 you examined after the fact and found no indication of 19 cracking, et cetera, you had reasonable confidence that you
'20 would be off the fatigue limit.
21 Whereas, at'10 to the 6th, you are still in the 22 never-never land, because you can look at data and find that 23 at that juncture point, the fatigue limit has a plus or minus
~q 24 range of about 500 KSI 25 MR. SHEWMON: But the austenitics would not have an
351 1
/ l
! 1:
T ,/ 2 MR. BUSH: No, no, I said ferritics. The 3 austenitics is a different animal The curve keeps sliding 4 down, sliding down.
- 5. MR. SHEWMON: I was talking about austenitics.
6 MR. ETHERINGTON: Isn't it also true that ferritics 7 deals in a mildly corrosive environment that has no endurance 8 limit?
9 MR. BUSH: Any time that you get cracking of any *
. 10 nature on there, then the ballgame is over, because you now 11 pass the initiation phase and then the propagation. If you 12 have corrosion, then you can get that --
IS MR. ETHERINGTON:
[}N/
What I am suggesting really, is 14 even in the pWRs there might be no endurance limit in water.
15 MR. BENDER: I'm not sure I would know how to 16 respond to the second bullet up there. If it really turned 17 out that you wanted to --
18 MR. O'BRIEN: How would we respond?
19 MR. SIESS: Let him go through the list, Mike.
20 (Slide) .
1 21 MR. BENDER: Okay, 22 MR. SIESS: You are anticipating a little bit.
23 MR. BENDER: I'll wait.
-, 24 MR. SIESS: Start at the top.
'~~
25 MR. O'BRIEN: The first bullet says, see if you can
352 1 apply LOCA plus SSE decoupilng for other than CE and -
% j. 2 . Westinghouse. And since Volume 4 was published, we finished 3 work on BSW and it does fit in. We have not finished our work 4 Hon GE.yet.
5 That takes us down to the next bullet. This is a 6 very large program under Chuck Sorpan regarding testing of 7 degraded piping, ductile piping.
8 Now his program deals a lot with static tests, but 9 there is dynamic loads like earthquake and water hammer that
- 10 are planned, it is not the whole program, but some of his 11 programs deals with dynamic loads l'ike seismic. When Jack 12 Strosnider was here and doing it, that's what it was. Milt is l (/~~) 13 doing it now, i
\_/ .
14 But there is a seismic aspect to that degraded-15 piping program which will tell us what is the capacity of 16 degraded. piping, piping with cracks in it...to withstand water 17 hammers, which would be very important. I mean, we don't even 18 have an allowable f or wa t er hanner . How can we design for 19 them. We don't know how good it is.
20 MR. SIESS: . John, I don't understand the. caveat.in 21 parentheses at the top of the slide. That says "not sorted by 22 issues."
23 MR. O'BRIEN: Oh, because i have event combinations,
. ,ess 24 water hammer -- see, we had --
- '~
k, ')
25 MR. SIESS: Oh, okay. Each one is separate, but
353 1 they are not categorized in those.
f) 3 q /. 2 MR. O'BRIEN: I didn't say that this deals with
< S event combinations, this deals with water hammer.
4 MR. EBERSOLE: John, may I ask you a question.
5 Some of these hydrausic systems 'nvolv'ing i vessals, 6 pressurizers or boilers or whatever, they suffer transients in 7 which they depressurize due to say stuck safeties?
, 8 -They depressurize, and they have high volume'tric j
9 flows that depressurize the system. The makeup water comen i n-10 at prodigious rates and it doesn't stop, it keeps on coming 11 until it gets to the orifice which is discharging vapor up to 12 that time in all it wants. ,
/ 13 That orifice is confronted with a solid stream of i
U) 14 water.
15 Does that produce a shock on the system that is E 16 significant?
17 MR. O'BRIEN: Sure.
18 MR. EBERSOLE: Do you routinely look at that?
19 MR. O'BRIEN: No.
20 MR. EBERSOLE: How do you know that it isn't
.21 damaging?
22 MR. O'BRIEN: Our experience, i quess.
28 MR. BUSH: I think what you have to do there, Jesse
! 24 is, there are some rather definitive criteria on testing of O 25 safety valves, and what you have to do, et cetera. And I
- , . - - , - - - . . - _ - - ,_,,,-----..._~v -, ~ - , _ _ , . . - .
- 4 354 1 think --
i A
\
\s_/ 2 MR. EBERSOLE: Do they test them in this mode?
3 MR. BUSH: There is a sequence of testing that --
4 for rates, et cetera. Usually -- you are really talking the 5 slug effect in there.
6 MR. EBERSOLE: Yes.
7 MR. BUSH: Now you want to realize that these have a 8 fairly good aperture when they are open.
9 MR. EBERSOLE: I know. I know the physics.of the 10 problem. I am just asking what is the extent of the shock 11 produced by this sudden choking of the orifice with solid 12 liquid when you have input flow rates that are prodigious.
[ T 13 MR. BUSH: Well, one of the things that can happen
\s /
14 is, you can blow the whole valve off. '
15 MR. EBERSOLE: Well, what about the vessel itself.
16 Or, other points in the system that are weaker than the valvo.
17 MR. BUSH: Oh, okay. You are talking of a different 18 thing. You are.really talking of a reflective wave that comes 19 back in there and goes back up the pipe --
20 MR. EBERSOLE: It is the whole system.
21 MR. BUSH: Okay. I was thinking of it in the 22 context of the valve per se. You are really talking of the 23 reflective --
7-s 24 MR. EBERSOLE: I know it would dependent on the
- N, 25 length of pipe and the velocity of fluids in it that is
355 1 f.eeding this system.
A
's 2 I am just asking in a systematic context, is this 3 looked at.
4 MR. SIESSs Volume of the tank.
5 MR. EBERSOLE: Or, should it be?
6 MR. O'BRIEN: Has it ever happened?
7 MR. BUSH: Yes.
8 MR. EBERSOLE: I don't know. You wouldn't know if 9 nothing happened..
10 MR. BUSH: The answer is it has happened. There 11 have been two cases, at least, where we blew the whole bank of 12 valves. One of them was at Robinson and the other was at
' I 18 Turkey Point.
(
14 MR. SIESS: Those weren't slugs, those events. One 15 of them was just a lateral force.
16 MR. BUSH: You have got the shock load and the 17 rotational 18 MR. SIESS: That was Robinson.
19 MR. EBERSOLE: It sounds like a phenomenon that 20 ought to be routinely examined, especially if we.have got.long 21' feeder lines. That is the old, ancient RAM, is a good
-22 example.
23 MR. BUSH: The business of reflective waves has been
-% 24 looked at. But I don't know if it has been looked at in this 25 specific context you are talking about. That one is looked
356 1 a,t, , but for other reasons, I think.
fy,/. 2 l' suspect.the answer is, in the context you are 3 raising the question it probably isn't.
4 -MR. SIEGS: He has raised it for the vessel 5 upstream.
6 MR. BUSH: it is not just the vessel, it is also the i
7- piping.
8 MR. EBERSOLE: The whole thing.
9 MR. SIESS: Won't the wave be worse than the water -
10 hanner itself, as far as the piping is concerned?
11 MR. O'BRIEN: We have not looked at it. Nobody has 12 raised it but you.
~
13 MR. BUSH: It is the water hammer. Really, what you
}
14 are doing is getting the reflected wave.
-15 MR. SIESS: You are addressing waves originally in 16 connection with the vessel 17 MR. EBERSOLE: It is analogous to the ancient RAM 18 that used to oumo water.
19 MR. SIESS: Well, water hammers will break oloe. We 20 know that.
21 Okay, John.
22 MR. O'BRIEN: The next bullet is ontv for people who 23 really love analysis, and deals with thinas that if you are
,g 24 not into analysis don't make a lot of sense. But, they are in 25 the multiple support recommendations that were developed.
357 1 They hinge on phase correlations -- and we have not 7 .
' (_) 2 extensively looked at it. And we will look at it in the 3 Office of Research.
4 There is another problem which the analyst has to i
5 deal with on closely spaced modes. And we are also going to do 6 some more work along those lines.
7 (Slide) 8 My final slide is -- number three on the top there 9 isn't so important because as I said, pipe frequency modes 10 just -- the use of algebraic summations for high frequency 11 modes only tends greater realism, and doesn't necessarily have 12 a very large impact, it could affect it conservatively or
.[LJ} 13 unconservatively. But we thought that we should do a little 14 more work to show the realism to the extent we can.
K
/
15 The last bullet is an attempt to make the piping 16 damping values adopted for seismic loads by the pRU to see if 17 we'could use the same dampings for SRU discharge in other 18 environments',~because right now those damping curves are 19 restricted to seismic.
20 This is a curious thing, because Reg Guide 161,.
-21 which says seismic damping is applied to every loading 22 situation, but when the pVRC came out they said only seismic.
23 So , we are going to do some testing with high frequency
.fs 24 inputs on piping.
/ \
Q 25 That's my presentation. The report is a best seller k
358 1 in.the sense that we are ordering 300 new copies. We have 60 (m)
. j 2 unfilled orders right now.
3 (Laughter) 4 MR. SIESS: What was that last statement?
5 MR. O'BRIEN: See, we sell these things for $8.50 6 rsch.
e And we have exhausted our stocks and we are producing 7 300 more. But, we don't get any royalties.
8 MR. SIESS: That must be why I haven't gotten two 9 sets like 1-get of everything else. -
10 MR. SHEWMON: I've gotten three.
11 (Laughter) 12 MR. SIESS: John, I don't really mind all these 13 people that are enthusiastic about analyses going through this
.' [~ } .
\J 14 stuff. It just bothers me when they start believina the 15 results.
16 (Lauchter) 17 l'm amazed at how little recommendation for research 18 came out of this. These last two slides, and vour 19 recommendation for research. I thouaht thev were rather l
20 minimal L 21 MR. O'BRIEN: What we succest in addition to --
22 MR. SIESS: No, I am lust wonderina whether this was 23 before or after the budget cut.
, . ,c, 24 (Lauchter) l 25 MR. BUSH: I could comment on his last bullet up t
L i
^
b 359 1 .there.
J3 '
)
1' j 2 Gerry Bitner has picked up quite a few more points 3 out in the ranges of interest from 33 to 100 hertz. He is 4 just about ready to decide to change it, from what I would 5 call an interim position to a final position, because even 6 though theoretically we don't understand why there should be a 7 change, all of the data we get --
and we have been getting 8 quite a bit -- show exactly the same thing, that the damping 9 values are high. At zero to 10 hertz they begin to drop off,*
10 and they stay at a lower value.
11 MR. SIESG: They stay fairly constant from 33 on?
12 MR. BUSH: Well, obviously the population of the 13 data points is not so great there. We have a great number
\_
14
~
earlier. But he has been adding points. And the last time i 15 talked to him, which was only about two weeks ago, he had just 16 about decided he is going to put the document out, it won't
-17 be out as a WRC bulletin, it will go out as a PURC technical
- 18. report.
19 He has just about conceded to make the change from 20 interim to final because he doesn't -- hasn't found any data 21 to change his direction.
22 MR. SHEWMON: How much of that damping is in the 23 pipe and how much of it is in the supports?
- 24 MR. BUSH: The tests have covered.a very wide N' 25 spectrum of support spans and so forth. So I would think a l
1 i
,. - - . _ , _ . - - -_,,._.m_. _
360 1 gr_ eat deal of it is in the piping.
.m i \
( ,/ .2 Obviously, some of it is in the supports. So, 1 3 don't think I could answer your question exactly.
4 MR. SHEWMON: Is this dependent on ferritic or 5 austenitic?
6 MR. BUSH: We see no obvious difference at all 7 Of course, it is still in the elastic range. If you got in 8 the inelastic, then you might see something different in that 9 respect.
10 MR. SHEWMON: I just wondered if there is a 11 frequency dependence to the elastic damping.
12 MR. BUSH: That, I just don't know.
.[ ) 18 I will say there is one other aspect. That is, if
\ j 14 you put insulation on the piping, that has a tremendous 15 impact. You are now talking of damping values, it is 30, 40, 16 50 percent as contrasted to 5 percent.
17 MR. SHEWMON: But it is used both ferritic and 18 austenitic?
19 MR. BUSH: Yes.
20 MR. MICHELSON: Chet, I think there may be a comment 21 back here.
22 MR. VAGINS: Bill Vagins, Research, Staff.
'28 Mr. Ebersole's question I think was a very valid
-s 24 one, and I think needs some clarification.
N/ 25 Several years ago, ten years ago, we started a
361 1 program called " plenum Fill Experimants," which was partially D
kj 2 to address the exact problem of what happens when you have a 3 loss of coolant and you have massive injection.
4 You can consider the condition where you have a 5 massive loss of coolant, depressurization of the system. And 6 then you finally get down to firing your LpSI, your 7 low pressure injection system. At this point you have your 8 whole system deadheaded, at 700 psi. And that fires when they '
9 reach that level, and you do get an injection, a very large -
10 flow of injection into a steam system, a two phased system.
11 At this point, for instance the Combustion at 12 Westinghouse will will be injecting into the cold leg.
l# D 13 Babcock'and Wilcox probably directly into the vessel. There 14 is no problem with the vessel There is enough volume and 15 enough space to ensure there is no shock whatsoever.
16 However, into the cold leg and into the ECCS lines, 17 you will be getting water hammer, steam acceleration or water 18 slugging, or any of the three combined.
19 And the only reason i bring this up is that this is
. 20 the one design condition where water hammers should be 21 considered. We don't want to fire the LpSt and then rip out 22 our system at the same time.
28 MR. EBERSOLE: Ye.g .
fg 24 MR. VAGINS: So that when we look at removal of
('-) 25 constraints, I think one of the things to seriously consider
362 1 La the maintenance of such restraints on the ECCS lines, ECCS A.
\,,) 2 system.
3 MR. EBERSOLE: Water'can occur at frequencies higher 4 than having a LOCA because you can get a stuck safety, or --
5 MR. VAGINS: Well, those would be beyond a design 6 basis. But even in design, to fire your low pressure system 7 you will be firing from a deadheaded position. An 8 instantaneously -- almost instantaneously opening system. And 9 that is inherently a water hammer design. '
10 MR. EBERSOLE: Right.
11 MR. MICHELSON: How about the case of the reactor 12 vessel overfill, or steam generator overfill into the piping?
f'} 13 That also has the potential for serious water hammers.
v 14 MR. VAGINS: If you are talking about pWRs, you are 15 talking about water injection into a single phase system.
16 MR. MICHELSON: Steam generator now.
17 MR. VAGINS: Secondary side, steam generator side, 18 yes.
19 MR. EBERSOLE: He's talking about overfill, which-20 is suddenly terminated by hydraulic filling of the secondarv 21 side.
22 MR. VAGINS: No question. We have had water hammer 23 on the secondary side. Which is the case where we had a
'24 cracked pipe.
N,J 25 MR. BUSH: Indian point 2. Back in the feedwater
r 363 1 l i.n e .
D
( ,) 2 MR. MICHELSON: That was the feedwater side of the 3 situation, not the steam side.
4 MR. BUSH: Also Maine Yankee.
5 MR. MICHELSON: That was also feedwater side.
7 MR. SIESS: .Okay, Larry?
8 MR. SHAO: (Slide) 9 Volume 5 is a summary of the volumes 1 and 4. -
-10 The way we work is, all the scope and objectives 11 were set up by the NRC piping Review Committee. But the 12 actual draft report was written by a task group.
[}
%d 13' After the task report was written, it was submitted 14 to the NRC piping Review Committee for review and comments.
15 And, after our review and comments, it was then sent to other 16 major offices such as NRR, Research, l&E, and also the Region 17 office for review and comments.
18 After we incorporated all their comments, then the 19 report was published.
20 (Jhen we star ted wr i t ing volume 5, we found there 21 were so many recommendations, there is no way the NRC can 22 work on all the recommendations. So, we decided to categorize
. 28 them into A. B and C.
e 24 The A category, of course, are the most important 25 areas, and we feel NRC should work on them right away. But, B I
1 1
364 l
~1 and C are important, too, but of course, not as important as O
\ l x_,/ 2 category A.
8 '
in general, we feel -- the piping Review Committee 4 has suggested many changes, and we feel some of the changes 5 are very substantial These changes, if they are made, should 6' have a positive effect on overall licensing process. It will 7' increase overall safety and reliability.
8 it may require changes to rules, Reg Guidos and 9 standard review plans. And also it may require change to the' 10 ASME code.
11 (Slide) 12 I was only prepared to talk about all these A p
? I 18 categories. But now I find all the A categories have been
\,_)
14 covered yesterday and today.
15 MR. SHEWMON: Don't feel you have to talk for an 16 hour to explain it.
17 (Laughter) 18 MR. SH40: So, I don't want to talk unless you want 19 me to talk.
20 MR. MICHELSON: I have a question on an A category 21 item, which is item 5, which is the decoupling of the seismic 22 and LOCA events.
28 What I wanted to ask you is in the case of boiling
/~Ng 24 water reactors and systems such as reactor water cleanup, that
-25 system sees normally high full reactor pressure, full reactor
365
-1 _t_e,mp er a t ur e i n its operation. And yet it is nonsafety f).
-( J' '2 related, it is in many cases non-QA. In ,some cases it is even 3 nonseismic.
4 Now, in a case like reactor water cleanup, are you 5 going to still decouple the LOCA and the seismic event? It is 6 a LOCA when the pipe breaks.
7 MR. O'BRIEN: The answer to-that is --
8 unfortunately, A part says "where leak before break is 9 applicable." That's wrong. It should have said "when -
10 justified," which Larry is going to tell you about. And right 11 now the decoupling is not applicable to anything other than 12 primary loops of the systems' three pWR vendors, and we are h
d 13 looking at GE.
14 So, what you did was you homed in on a mistake that 15 went forward. It shouldn't be "where leak before break is-16- applicable" but it should say "when justified."
17 MR. SHAO: They key word is "when justified."
18 it doesn't mean that we automatically decouple.
19 MR. MICHELSON: So I guess you don't'know the answer T
20 yet until somebody asks:-- well, nobody is going to ask. But 21 the facts of life are it is designed this way already, and i 22 guess nobody is going to ask to make it a leak before break 23 system, I suppose.
7g 24 MR. SHAO: If they ask they have it justified.
25 MR. EBERSOLE: I might comment that Carl is homing
366 1 in_on one of the most devastating accidents you can have,
. j%, .
1 ,). 2 which is continued primary discharge into machinery space 3 because of valve unreliabilities to close and with little or 4 no information on the dynamic competence of valves to close 5 against a full discharge flow.
6 And the end result of that is it is regressive in 7_ .that it destroys the mitigating equipment.
, 8 MR. MICHELSON: The real problem here of course is 9 that my concern is should the valves be designed to close off -
10 the leak before break, or should they be designed to close off 11 the break, keeping in mind they are nonseismic, non-QA in some 12 utility cases.
f~ j 13 i just wondered if you had a position or even a
\d 14 thought on it, and how I was to read this. But as i 15 understand it, it would not even apply at this time. The 16 committee didn't look at that particular ki,nd of situation.
.17 MR. SHAO: No.
18 MR. SIESS: I was looking at the B and C category 19 recommendations, and I was just wondering, your A-2 is to 20 modify the seismic damping values. And I go all the way down 21 to C-1 to see spectral shift.
22 Why Is --
23 MR. SHAO: Spectral shift is only about 10 percent
,.~ 24 --
I i
25 MR. SIESS: I know, but it is just as easy to do as i
h 367 1 modify-the damping the values.
-\ j 2 MR. SHAO: It can be easily -
3 MR. SIESS: War e these be.ud vr. . i np v. i a.eue F 4 MR. SHAO: Osud vre i .nw u s 6. su u arou vi w ur.:= uuuur ic e .
5 MR. o!""7- Cccruce, .f L:u are 3:!m; to enodify the 6 Rea Aselda 161 --
7 Mn c M(C - It can ba enmely done. As a matter of A fact the ASME code is already put in the code case, and o etrandy Bob Bosnak has been used in many cases.
- to The only reason we didn't put it in A, it doesn't 11 have major impact.
12 MR. SIESS: Let me go back to your first slide a
(. v 13 minute.
14 What kind of changes did you make in your 15 recommendations as a result of the comments received from the 16 NRC offices?
17 And, to what extent were they related-to the level 18 of knowledge and to the problems of application and 19 implementation?
20 MR. SHAO: To tell you the truth, all the experts --
!~
21 there~ has already been dispute. people from the major offi'ces 22 already participated in the NRC piping and Review Committee.
23 MR. SIESS: So the things like John talked about on 24 water hammer came out of the original group?
O 25 MR. SHAO: Mainly because as you know. Alec Sirkus
368 l
1 wh,o worked on A-1 is also on John O'Brien's group.
m.
k,) 2 MR. SIESS: Did you have any differing professional 3 opinions?
4 MR. SHAO: I think Spence Bush has a little bit.
5 MR. SIESS: You didn't allow for any additional 6 remarks.
7 MR. SHAO: Finally, I think they compromised.
O MR. SIESS: Reached a consensus.
9 MR. SHAO: Reached a consensus. -
101 MR. SIESS: I expected that.
11 MR. EBERSOLE: May I ask in A-6, where are you going 12 to modify leak detection equipment?
en
/ \ 13 MR. SH4O: Let me give you a Uugraph.
's 14 MR. EBERSOLE: You have got it down there now.
15 A-6. This leakage comes off of hot pipes that are cracked, I 16 guess, don't you think?
s 17 MR. SH40: That's a recommendation. Mainly we want 18 to change from BWR piping, instead of 5 gallons per minute, 19 change it to 3 gallons per minute. Instead of a surveillance 20 period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> change it to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
21 MR. EBERSOLE: This vapor wi l l- come of f and will 22 appear as condensate on the drains from the air coolers and 23 the containments, is this correct?
i fg 24 So you are going to accumulate in some common i \
V 25 receptacle the drains from the air coolant condensation
369 1 pr.ocess?
( ,/ . 2 MR. SIESS: Are you talking about how they detect 13 leaks, Jesse?
4 MR. EBERSOLE: Yes. How are they going to find that 5 3 gpm when it comes out as steam into the general environment?
6 MR. BUSH: Of course one method that is used 7 routinely, is the activated products technique which certainly 8 works well with steam, and it can be calibrated to a degree, 9 at least. It certainly is an early warning device. -
10 And since most of these cracks we are talking about 11 here are in the .0002 --
t or 2 gpm range, they do give you an 12 early warning on damping.
13 I admit when you get down to the 3 gpm, you probably
_ %.{ '/}
14 are ending up more with the sumps as much as anything else, 15 which means that you have had condensation and rundown which, 16 of course, may take a matter of hours or sometimes days.
17 MR. EBERSOLE: Where are you going to draw the line 18 that you have got to shut down and have a look?
19 MR. SIESS: 3 gallons per minute.
20 MR. EBERSOLE: S gallons a minute.
21 MR. MICHELSONr is that undetectable leakage of 3 22 gallons a minute, or -
23 MR. BUSH: That is nondetectable leakage, not 24 detectable. Because the detectable is supposedly already
.\
' }
25 taken care of --
370 1 _,
MR. MICHELSON: But the detectable leakage is also
( ,/ 2 an estimate, though, isn't it? You know where it is coming 3- from, in other words, but --
4 MR. SIESS: Did I hear somebody say undetectable?
5 MR. ETHERINGTON: Identifiable.
6 MR. SH40: Unidentifiable.
7 MR. MICHELSON: Unidentifiable.
8 MR. SIESS: For undetectable we don't worry about 9 it. '
10 MR. MICHELSON: Unidentifiable leakage has the 11 problem of the identifiable leakage, which is really also an 12 estimate. You think you know where it is coming from, you ys 18 think you know how much it is, and therefore it is detected.
]
14 If I have a valve stem that has been leaking for the 15 last two or three weeks, and I know it is 5 gallons a minute, 16 then if I see it go up to 8 gallons a minute, I don't know 17 whether that is coming from the valve stem, or whether it is 18 coming from a breakdown in a pipe.
19 MR. BUSH: Unless you are using a bleadoff 20 technique, where you are actually segregating the leakage from 21 the valve stem or from the seals, which is often done, too.
22 MR. SIESS: In the case you are talking about, you 23 would shut down and go find out.
24 MR. MICHELSON: But you now do this at 3 gallons a
. 25 minute?
371 1
MR. SIESS: That's what it says.
(m)- 2 MR. BUSH: - Th is was volume 1, and this was discussed
-3 at. considerable length. And the general feeling was at the 4 24-hour period which was used by some utilities, was excessive 5_ and that generally the value of 5 gpms which has been bandied
~6 around tended to be more on the basis of, well, it was hard, 7 difficult.
8 But we also checked and found that several plants 9 were operating at the lower levels and in a shorter time -
10 interval. So it can be don-a. It isn't an impossibility.
11 MR. EBERSOLE: Spence, in a practical sense, these 12 shutdowns may cost a million dollars if you shut down and go a
} 18 .in. ,
14 MR. BUSH: I agree.
15 MR. EBERSOLE: I was going to say, how does this-3 16 gpm relate to whether you can get in there,,and go find out 17 where it is without shutting down?
18 MR. SH40: All I can say is there are several plants 19 that indeed are operating in their tech specs in this four 20 hour or less business,.and at essentially the 8 apm rate,.
21 semi-voluntarily. I would say they might have had their arm 22 twisted a little bit.
23 And I am unaware that --
certainly we didn't get any 24 negative feedback during the meeting that this had represented
_(O
'~'
f 25 an excessive burden. Now that doesn't say it doesn*t. I lust
372 I s.a_y that we didn't get any negative feedback.
.r~%.
!' )
( j 2 1 don't think we have the right people here to 3 answer. The people who looked at it were people like Bill 4 Shack and others.
5 MR. EBERSOLE Well, as a general rule when you go 6 'in a PWR you open purge valves, don't you, and blow the 7 containment.
8 MR. BUSH: Oh, there is no doubt about it. In a 9 case like this you would be entering into the drywell, and to 10 enter the drywell you are going to have to shut down and go 11 into the system. And that takes time.
12 MR. EBERSOLE: You don't have to shut down every 13 tima you go into the drywell into a PWR l'm talking about,
[}
.% /
14 a dry containment.
16 MR. BUSH: That is strictly a BWR requirement. PWR 17 is one gpm.
18 MR. SIESS: This is a BWR requiremont because of 19 this intercranular stress corrosion factor.
20 MR. BUSH: That's right.
21 MR. SHAO: Also leak before break.
22 MR. SIESS: This is what they care going to pay for 23 leak before break. And even if they go in and replace all 24 their piping with NG, this is the price they have got to pay 73
- I.
25 for leak before break to get rid of the restraints.
I
I: .
373 1 _. MR. SHAO: Right, f( 2 MR. SIESS: Now, if they want to continue to assume 3 leak bef ore break , will you let them and not impose this?
4' MR. BUSH: 'You mean if they want to assume the 5 double-ended break? Is that what you are talking about?
6 MR. SIESS: 'Yes.
7 MR. BUSH: If they want to assume the double-ended 8 break, then I presume they wouldn't try to apply this then.
, 9. MR. SIESS: So, if I have got an operating BWR, I *
~
10 can leave it as it is, if it is designed as a current process.
11 Or, if I want to go in and remove pipe restraints --
12 and il think some of them have these honeycombed to keep from
..j 13' busting the drywell stuff --
if I want to remove that-stuff to 14 ' facilitate inspection and meet ALARA --
did you look at'ALARA?-
-15 MR. SHAO: For this package it says, normally the 16 postulated break, you also'have to remove.the cracked piping.
17 They have to replace with the good material.
18 .lf they don't postulate the break, they don't have 19' to use this.
20 MR. SIESS: Okay. But they should replace the 21 material anyway?
22 MR. SHAO: Replace the material for leak before '
23 break, s
-s 24 MR. SIESS: Replace the material, and at this leak V- 25 rate they don't have to put the restraints in?
374 1- , , _ MR. SH4O: Right.
/' }
' _,/
( 2 MR. SIESS: But if they replace the material and 3 what to put the restraints back in, they have to go back to 4 the old leak-rate requirements.
5 MR. BUSH: As a first step. I was thinking of other 6 things. There are things beyond that they would have to do, 7 if they want to go beyond that.
8 MR. MICHELSON: Boilers aren't doing any of this 9 yet, though, are they? Because your whole review was only for 10 the three brands of pWRs.
11 MR. BUSH: No. Four or five of them have replaced 12 their piping, their recirc piping with NG at this stage. That I~ 13 is the most obvious thing I can think of.
=
\
s 14 MR. MICHELSON: The rulemaking doesn't cover this 15 yet?
16 MR. BUSH: No. For leak before break you are 17 talking about?
18 MR. MICHELSON: Yes.
19 MR. SIESS: It is only pWRs.
20 MR. BUSH: However, you may recall when Ray made.his 21 , presentation, there was a caveat there that said if you have a 22 resistant material in a BWR, at least it was open to 23 consideration for that. That is as far as it went.
7g 24 MR. MICHELSON: Have BWRs actually now removed
, 25 their restraints?
i
_ . _ . _ . _ . , . _ . _ _ _ . _ . _ _ ~ _ _ _ _ _ . _ . _ _ _.__ _ __ _ __
375 1
MR. BUSH: Mo.
.\ j ~2 MR. SIESS: Not that I'm aware of.
3 MR. MICHELSON: I wasn't aware.
4 MR. SH40: No, if they come with good material, if 15 they want to remove --
6 MR. MICHELSON: This is.for the future?
7 MR. SH40: Right.
8 MR. SIESS: What would be likely to happen is, if 9 they are going in to review that material, they could remove 10 the restraints at the same time, impose this leak rate, and it 11 would be all right.
12 MR. BOSNAK: One thing, some of the BWRs that have IS repisced their piping have reanalyzed their piping and have
[Q']T 14 located restraints in accordance with today's standard review 15 plan.
16 in the past they have located the restra,ints in a 17 refitting or some other means. And they just brought it up to 18 date to meet the current requirements. So, they got rid of a 19 few restraints that they don't need to meet today's 20 prescription.
But, they didn't go into leak before break.
- 21. MR. SIESS: Now, Larry, the recommendations in the 22 , A, B and C categories are essentially an order of priority, 23 and, of course, of time?
fs 24 ' '/ou recommend they implement the A I t en. 3 , and then
(
25 go on?
f L-
h
?
376 1
MR. SHAO: Yes.
'A k ,) 2 MR. SIESS: So it is mainly a questi,on, you would 3 like to see all of them implemented in this order?
4 MR. SHAO: Yes, in this order,-because always the 5 NRC cannot work on all at once.
6 (Slide) 7 These are the so-called A category on proposed 8 research. A lot of them are ongoing research. We feel these 9 are the most important areas. In case of any budget cut,
- 10 these areas should not be cut.
11 A-1, I think John just talked about. That is the 12 degraded piping program ur. der Chuck Serpan.
13 Also, John covered H-4. Actually we already finished 14 B&W. The only thing that is left is GE.
15 On A-3 we talked at great length yesterday. That is 16 the program that EpRI, NRC and ENCO are wor, king on. The 17' purpose of the program, to verify the seismic margin, and also 18 to identify the failure modes. And we feel that program is 19 very important.
20 Under A-2, mainly it is to try to develop advance 21 techn'ique to detect and size cracks so that they can be 22 incorporated into the Section 11.
23 Another area we feel is very important is they have 7s 24 been using weld overlay. We don't know how to inspect pipes J \
V 25 that are repaired by weld overlay. So far we only call for
377 1 two cycles. There may be cases they want to use more than two
( ~.. 3
.,( ,/ - 2 cycles, so we would like to be-able to develop an inspection 3 technique to look at the pipes'that are repaired by the weld 4 overlay process.
5 The last item is, because everybody feels that leak 6 detection is so important, we should have a program, a method 7 to predict leak rate and validate the reliability of the leak 8 detection systems.
9 MR. SIESS: All of these are ongoing? -
10 MR. SHAO: We have all programs in this area. Let 11' me show you a Uugraph.
12 MR. SIESS: All of these are in the FY1985 protect?
[~' 18 MR. SH40: Yes.
\
14 MR. SIESS: Now the Os and Cs, did any.of those get 15 into 1986 and 1987?
16 (Slide) 17 MR. SHAO: We have programs in B and C, too.
18 MR. SIESS: You have some ongoing now?
19 MR. SH40: Yes.
20- MR. SIESS: My question, to put it in context, are 21 we.looking at the 1987 budget now? I don't know that we have 22 identified the Piping Review Committee recommendations in 23 that. I am just wondering which ones of these are in 1987.
~, 24 MR. SH40: 1.can't answer your question right now, i i
'\# 25 MR. SIESS: Can you answer it two weeks from now
378 1 whon we do the research committee.
,e
() 2 MR. SHAO: Sure.
3 MR. SHEWMON: I would like to go back to the 4 previous slide for a minute.
5 (Silde) 6 You have got two sets of recommendations.
7 MR. SH4O: One for research, one for regulatory-8 actions.
9 MR. SHEWMON: Okay. I guess I am looking at A-2. -
10 MR. SH4O: You want to look at which-one? This one 11 or the other one?
12 MR. SHEWMON: I want to look at that one. I look at
/"] ' 18 the last line of A-2, and I wish it wasn't there because it
'd 14 sounds like you are only interested in inspecting weld 15 overlays, and you don't care about the cast elbows and other 16 things we were talking about.
17 MR. BUSH: I think you should realize that these are 18 essentially taken right out of the reports. This one is taken 19 out of one which dealt with stress corrosion cracking, which 20 is not a problem in cast stainless, 21 The reason for this was the fact that we had p u t' the 22 caveat that you couldn't permit overlay clad for more than a 23 certain period of time. But we were saying, see what you can 24 do by inspecting through there.
25 1 might comment that they now have a technique that
379 1 w i_ I l inspect through the clad or the overlay.
k ,/ 2 So that is the reason, paul They are taken, 3 essentially, close to verbatim. We didn't try to play cames 4 with the words on them. And so that would be the reason.
5 MR. SHEWMON: Good enough.
6 MR. MICHELSON: You are aware of the pipe locks, of 7 course. Are they going to be used anywhere?
F 8 And if so, how does their usage fit into this plan, 9 scheme of things? '
10 MR. SHnO: Ralph is going to talk about that.
11 MR. BOSNAK: I could mention there i s activities 12 among several of the utilities to utili=e the pipe lock, it A
) 13 is a proprietary device on -- I am not sure which -- I think
.( V 14 one of the Commonwealth Edison plants.
15 Also, there is a move to look at a mechanical lock 16 device in lieu of IHSI. In other words, this would provide 17 the compressive stresses on the inside of the pipe. And in 18 fact, as I have heard, provide compressive stresses more 19 through the whole regime than lHSI would do.
20 So, that is another device that is being looked at.
. 21 And these'would come in on a kind of case-by-case basis to see 22 how they are going to use them.
23 ' pipe lock, if you are going to use pipe lock, you g- _
24 would have to reanalyze the whole system for the application 25 of the pipe lock device.
b
380 1 . MR. MICHELSON: Would it be possible if I use a pipe
(_) 2 lock to say that 8 no longer have a break at that location?
3 And, would I have to put in a detection system and so forth?
4 MR. BOSNAK: The pipe lock device has been tested 5 with a break in that location. in other words, the whole --
6 MR. MICHELSON: Double-ended rupture is what I was 7 referring to at a break.
8 MR. BOSNAK: We are not trying to mix pipe locks and 9 breaks together. But the pipe lock device, the claim has been' 10 made for it that even though the flaw goes all the way 11 through, that device will stay en place.
12 MR. MICHELSON: Therefore there would be no break (A)
%./
13 there. There would be a leak, but not a break.
14 MR. BOSNAK Well, it is not being proposed for that 15 purpose.
16 MR. MICHELSON: I am puzzled about it.
17 MR. BOSNAK: It is being proposed in ifeu of weld 18 overlays.
19 MR. SIESS: But not in lieu of replacement.
20 MR. MICHELSON: I thought it was. I thought people 21 were considering that a lifetime device. .
22 - ny MR. BOSNAK: Well they would like to, but the Staff rkl' 23 is not'{}t j ready. In other words, we are still looking at the l q[fR if-'si 24 applicaD'd>1s and we still are looking at it as a limited f
25 application device. We may change our mind in the future, i
i e
^
381 1 _ _ , MR. SHEWMON: It depends on whether the problem is
~s
(_) 2 Bill Mcdonald or Tom Bosniak.
8 MR. SIESS: But reccanienda t i on A-4 says replace.
i 4 Now that is the Piping Review Committee's 5 recommendation, right?
6 MR. SHAO: Actually we should say the preferred 7 action is to replace. The preferred action is to replace.
8 MR. BUSH: We only recommend.
9 MR. SIESS: I said recommendation. -
10 MR. SHAO: If you read the letter to Dircks, we 11 clarified this. I say the preferred action is to replace if 12 you look at the Dircks letter on item A-4.
13 MR. SIESS: Okay, the preferred action is to 14 replace. If you want to do anything else, convince me.
15 MR. SHAO: Another possibility, somebody will say I 16 want to change to hydrogen water, also do-1,HSI in lieu of 17 replacing. That is also acceptable.
18 MR. SIESS: Okay.
19 Now at some point, and I don't know whether this is 20 it, we need to know what you expect of us-in terms of comments-21 on the major recommendations, at least, those that we expect 22 to implement. And to do that, of course, we need to know the 23 implementation approach.
,s 24 Obviously, if it is a rule, we comments if it is a
,) '25 Reg Guide, we comments if it's a standard review plan, we now
382 l
1 have no formal mechanism for reviewing standard review plan,
~f
.(Q ~2 so we cou I d connen t on reconmenda t i ond .
3 Do you want commen t s -f r om the ACRS on the 4 recommendations of the Piping Review Committee, or do you want 5 comments on the various stages of implementation as they come 6 along?
7 MR. SHAO: 1 think right now I would suggest to have 8 comments on some of the major recommendations.
9 MR. SIESS: As recommendations of the Piping Review-10 Conn i t t ee?
11 MR. SHAO: Yes. Category A items.
12- MR. MICHELSON: Just in category A, I gather?
J/ 13 MR. SIESS: Yes.
.N 14 Now the category A items did not include the 15 schedule or exemptlon rule, which we may -- we wiiI probably 16 comment on as a rule.
'17 MR. SH4O: N o '. Purely technical recommendation.
18 MR. SIESS: But it does include the broad-based rule 19 and some Reg Guide changes.
20 Now, could you refresh my memory as to what GDC 30,.
21 31 and 32 are?
22 MR. SHAO: I think GDC SO relates to the quality 23 of primary coolant components on fracture mechanics and f- 24' inspection.
25 MR. SIESS: 31 is --
383 L 1 , , ,
MR. SHAO: Is on related inspection of primarv 7
l 2 coolant components.
3 MR. SIESS: 32?
4 MR. SHAO: 32 is on inspection, one is on quality,
! 5 general quality, one is on inspection, and I forgot the other 6 one.
l 7 MR. SIESS: Now, do you have to change those for the 8 broad-based rule? It only addresses GDC 4. Do these others 9 .have to be changed?
- 10 MR. SH4O:
11 MR. SHEWMON: I think GDC SO, 31 and 32 are a matter 12 of ' statements. I don't think you change.
![ D 18 MR. SIESS: They are in a column saying documents V.
14 ' requiring change.
15 MR. SHAO: We say possibly. They are a general 16 statement; you have to have a good primary coolant componont, 17 you have to inspect the primary coolant component, and so on.
18 .MR. SIESS: Okay~. Any other questions for Larry?
'19 (No response) 20 We are down to item lli on the agenda.
21 Is there anything you want to bring up on tnat, 22 paul? This is 1.46, 1.48 Reg Guide issue?
23 Well apparently, you didn't put it on either,
,s 24 Let me say something, maybe we can get it straight, g
25 We got information that was part of the i mp l emer it a t i on , Reg
384 1 Guides 1.46 and 1.48 were to be withdrawn and replaced by-
/~N
!\ ,/ ~2 modified revisions to the standard review plan.
3 The question was raised in the ACRS about this 4 procedure. In addition, we learned that this now was a new 5 policy. To the extent possible, Reg Guides were to be 6 replaced by standard review plans, which we hadn't heard of.
7 Maybe it is not true.
O But, it has been the practice of'the ACRS to review 9 Reg Guides. This was a practice implemented by the Staff. And 10 our review has also provided an opportunity for public 11 comments, but not limited to industry. comments.
12 tJe have no methodology of procedure for reviewing
- p 13 standard review plans or ~ branch technical positions. And I s
14 haven't found any strong sentiment towards that,.since we 15 still have enough other things to keep us busy. But, if our 16 workload got down we might want to get into that. That would 17 take care of a lot of time.
18' But, I had scheduled some discussion of the 19 procedural, philosophical, whatever, idea of replacing Reg 20 Guides by standard review plans for the next meeting of the 21 Regulatory Activities Committee, which I think is June 4th.
22 I think the Staff at some level was goina to come in 23 and talk about that.
.,-ss 24 lt is not so much these particular guides, as the i I \
~Y 25 general idea.
385 1 __ MR. BYRNES: This is Jack Byrnes from the NRC
-[(, 2- Research Staff.
3 As far as 1.40 and 1.48 is concerned, these were not 4 being looked at as a chance in policy, not presenting changes 5 -- incorporating changes from the guides into the standard 6 review plan and not, bringing them to the ACRS. It is not the 7 policy, but it is somewhat of an isolated case.
8 I think what has happened here is we were 9 interpreting the memo between the Staff and the ACRS in June 10 of 1983, which was referring to the coordination, about facts 11 and so forth, how to ao about these.
12 And this was indicating there that the crimarv areas l.
. 18 of discussion would be related back to rules and the,maior s_ .
14 policy matters 15 And these two particular quides, there was no
- 16. policy matter that we could see was involved from a technical 17 sense, from a licensino sense. I think this is why we 18 basically did not come to the ACRS on this.
19 MR. SIESS: Well, I think the memo is not very i
20 helpful We were reviewing Regulatory Guides long before we 21 had the Memorandum of Understand ing wh ich wa s ma in ly re la t ing 22 to rules. At some time after TMl they thought we ought to 23 review rules. That is when we became the Regulatory l
l f3 24 Activities Committee, rather than the Rea Guides Committee.
I a l
V. 25 The question that came up was, if there was going u
r 386 1 to be a general practice of moving stuff from Reg Guides into
/
k,D) 2 standard review plan, then there would be a change in the i
S review process. We would not be reviewina standard review plan i 4 items -- we haven't in the past. Industry would not --
5 publicly industry would not have a chance to comment on them, 6- We thought we would like to sort of explore why this was being
- 7. done, what. regulatory purpose it served and so forth.
8 MR. BYRNES: There again, it is as far as I can see, 9 no standard practice going to come about. Actually for the 10 guides that came out, I guess it was in December of 1981, or 11 something, the NRR had approached us and said, hey, these 12 guys are not being used by the industry, by ours31ves. The
[ 13 information that is contained in that has been incorporated in 14 the standard review plan. in fact, even expanded on those, 15 which made the standard review plans more act'ive than the 16 guides themselves. ,
17 So therefore, they suggested that we just drop the 18 guides.
19 MR. SIESS: But the guide -- when something is in a 20 guide, an Applicant can put in his FSAR that he will c omp i.y 21 with Regulatory Guide 1.46, and that then is an accepted 22 commitment.
~
23 Now, what does he do now? Say he complies with 24 standard review plan section 4.3.2.6.8(i)?
7-s 25 MR. BOSNAK: In the case of the Regulatory Guide
387 1 1s46, that. dealt with pipe breaks inside containment only, N ,)
s 2 only for Class I and I believe Class il systems.
3 The standard review plan 3.61 and 3.62 came out in
- 4 the mid-1970s and they expanded it. In other words, they 5 cover all high energy lines, not only Class I, Class 11, Class 6 Ill and non-ASME class lines.
7 So now the Applicants come in and say thev are coina 8 to comply with all aspects of those two standard review 9 plans.
10' MR. SIESS: They are referring to standard review 11 plans for compliance?
12 MR. BOSNAK: That's correct.
f~s\
t .18 You mentioned something about industry commenting on
-U l 14 standard review plans. These, when they are changed under the 15 current processes, go out for industry comment. So I would 16 expect'that the committee could comment on them as well at the 17 same time.
18 MR. SIESS: I'm not sure we want to.
19 MR. BOSNAK: If you want to.
20 MR. MICHELSON: If they are being used as the '
21
~
controlling document for review purposes, then it is just as 22 important for seeing that as seeing Regulatory Guides.
28- MR. SIESS: Any time the ACRS wants to review
! _jrg 24 standard review plans, I think they are willing to, but they 25 can go find another chairman of the Reg Guide Activities l
t
I a l 388 l l
l 1 Committee when that happens. Because the standard review plan
(_ 2 l've got is in two volumes, and we haven't even reviewed a branch technical positions, which is another type --
6 4 MR. BOSNAK: They are part.of the standard review 5- plan. They are an annex to the standard review plan.
6 MR, SIESS: Now the standard review plan and branch 7 technical positions are reviewed by CRGR. And since Reg 8 Guides'have been reviewed by CRGR, we have seen a lot fewer to 9 review.
10 1 don't know whether that means that the budget has.
11 been down to write new Reg Guides, or they are just not 12 getting through CRGR.
. 's
- t
~) 13 MR. MICHELSON: Or they are replacing it with the 14 ' standard review plan.
15 MR. SIESS: Yes.
16 Jack, correct me -- you said I was wrong, but let me 17 just repeat it again. I heard that the Office of Nuclear 18 Regulatory Research had decided, I guess was the word, to 19 limit activity on Reg Guides and try to get the same thing 20 accomplished through standard review plan changes. You said 21 that is not true, there is no policy involved?
~
22 MR. BYRNES: I don't know of any such policy 23 myself.
(^ 24 MR. SIESS: Okay, if you don't know about it it s <
r- '\,/
l 25 means it is not a policy, I guess.
l-
389 1 _ _ _ But, rather than bring 1.46 up to date to cover
. I(q
_j J
2 greater territory, just in the standard review plan --
3 MR. BOSNAK: The same thing happened with 1.48.
4 1.48 was written in about 1973 or 1972, and since then the 5 code was chanced to acolv different levels of allowable strp<<
6 for Class 11 and ill components.
7 in the earlier version when the Rea Guida was 8 written. that was not the case. So-as thema thinne har.ama Q available for industrv use. there had to ha woma nnlic.v nn hnw-10 to deal with it.
11 At that time, standard review olans --
this coes 12 back to about 1976 or 1977 -- 3.93 was written to cover the p' la i
- various events. events in combination and load
-N 14 combinations. So that. In a f f a r.t a u n a r e. a d a d what was in o=n 15 Guide 1.48. It no longer was appropriate.
16 MR. SIESS: Now, let's take damping. values, Reg
- 17. Guide 1.61 Why would it'not be equally logical to simply 18 include that for standard review plan rather than a separate to Reg Guide?
'20 Or, is it in the standard review plan.
21 MR. BOSNAK: The Reg Guide was available. So it is 22 referenced in the standard review plan currently.
23 MR. SIESS: But now, as you said, when 1.42 was s 24 available, but you added to it, so you put it in the standard 5
i \
j 25' review plan and didn't use it any more --
390 1
MR. SHAO: There's a difference. 1.61 not only f~).
(_) 2 includes damping value of piping, but also damping value of
-3 structure and other things. All the other things didn't 4 chango, only the damping value of piping has changed.
5 MR. SIESS: Suppose we changed the damping value for 6 'everything, would you then put it in the standard review plan 7 rather than revised-Reg Guide?
8 MR. SHAO: That would be a different story. But we 9 are only changing damping value on piping. -
10 MR. SIESS: I'm not on the piping Review Committee 11 now, I am on the question of Reg Guides versus standard 12- review plans.
s (N/ h is tJould it be the policy in the future, rather than 14 revising the Reg Guide, to simply put the revised version in 15 the standard review plan?
16 , .MR. BYRNES: Li don't see where that would 17 particularly be a policy in any. regard, even though it might 18 be strictly related.to one specific area.
19 -l think something like_the 1.61, with damping values.
20 applying to structures and mechanical systems, you would have 21 to'go back to a large number of. standard review plans to 22 modify it to include this in. it would probably be more 23 appropriate and no effort to leave this thing in 1.61.
24 MR. SIESS: So the thinking is there is not that
'(N 25 much difference between a Reg Guide and standard review
391
- 1. p.f_a n . They are comparable level documents. In one case, if n-km,) 2 -you can reference one --
if you can reference the Reg Gu'ide in
-S the standard review plan, then-that is convenient. So, it is 4 an adjunct to the standard review plan much the same way a 5 branch technical position is.
6 MR. ETHERINGTON: Do Applicants use and reference 7 the standard review plan?
8 MR. SIESS: He said they could.
O 9 MR. BOSNAK: Yes, they do. -
10 MR. BUSH: Extensively.
11 -MR. BOSNAK: Both provide guidance to 12 Applicants. They always have the alternative to come in with a
/ '
18 different alternative, a different way of doing things.
14 MR. SIESS: If it is early enough in the process,
~ .1 5 they do.
16 MR. BOSNAK: That's correct. ,
17 MR. SIESS: The last six months it is not very 18 1ikely.
19 MR. MICHELSON: If there are conflicts between the 20 documents, standard review plan versus Regulatory Guide, which 21 one takes precedent with the Staff?
22 MR. BYRNES: That's a good question.
23 MR. SIESS: There was no conflict between 1.42 and
-%s 24 the standard review plan, just a difference in scope?
I t
25 MR. BOSNAK: Just the scope is much larger. The
[
392 1 same thing is true of 1.43.
/~N s
\
\s / 2 MR. MICHELSON: And 1.46 3 MR. BOSNAK: 1.46, not 1,42.
-4 MR. SIESS: You said 1.48.
5 MR. BYRNES': 1.46 and 1.48 --
6 MR. BO3NAK: Both Reg Guides.
7 MR. SIESS: I'm sorry, you said 1.42 and meant 1.467 8 MR. BOSNAK: Yes.
9 MR. BYRNES: I might comment that no where are we '
10 getting out of the Reg Guide business. We have several 11 modifications to the guides going on right now.
12 MR. SIESS: I'm trying to get out of the Reg Guide j.
l .!,,\ 13 business.
%Y 14 (Laughter) 15 Okay, but what I said you agree with? You think of.
16 it simply as a comparable level, comparable in all respects?
17 18 If it is convenient to write a Reg Guide and 19 reference it in two or three places in the standard review 20 plan, you expect to continue that way.
21 A n d ,- if it is more convenient to put it in one 22 section of the standard review guide, you withdraw the Reg 23 Guide?
i
-w 24 MR. BOSNAK:
i That seems to be correct.
V 25 MR. SIESS: Okay. I will think about it a little i
l l
I i
393-1 b Lt . *
~( 2 Does it b'other anybody?
l l
3 (No response) 4 Who started the idea of the ACRS reviewing Reg 5 Guides?
6' MR. BUSH: I guess I did.
7 MR. ARLOTTO: I wrote the letter.
8 MR. SIESS: Spence was the first chairman of the Reg 9 Guide Committee. I have been the other one. '
10 How does it sound to you, Spence, all right?'
11 MR. BUSH: Yes.
12 MR. SIESS: We don't have to meet everv month now 18 vou know.
'b 14 MR. BUSH: That's better than it used to be.
15 incidentally, l looked at the standard review plan.
16 1 also looked at FSARs, where there has been reference 17 citations.
18 Certainly, as Bob says, they.do use that as a 19 mechanism for indicating a degree of compliance in some areas, 20 which is what was the intent, of course.
21 MR. SIESS: Paul, we are down to the last item.
22 I gathered from Larry that they would like to have 23 comments on at least the category A recommendations of the 24 Piping Review Committee. I guess it would have to be on the 25 basis, we still reserve the right to comment on the actual
394 1 implementation when it comes along, whether it is a rule or
,c~
(,) 2 Reg Guide change. Or, perhaps we could say even a standard 3 review plan change.
4 And in order to get comments on this, it seems to me 5 that we can't write a committee letter without having some 6 presentation of this to the full committee. That has usually i
7 been the procedure, Paul 8 I mean, there are exceptions. We have had 9 subcommittees write letters of comment, which were then '
10 transmitted by the full committee. But I would not recommend 11 that in this instance at all.
12 MR, SHEWMON: Now parts of this we have written-on
-A a i 13 before. There is this June 14 letter'on leak before break.
U 14 Have we written on the seismic /LOCA decoupling_
15 before?
16 MR. BOSNAK: I think some of that was in the June 17 14th letter as well L .18 MR. SHEWMON: I don't find it.
19 MR. SIESS: We don't with A-2 in that letter. No.
20 we did, LOCA/ seismic.
L 21 MR. SHEWMON: Okay. Fine I
22 MR, SIESS: And we had a caveat that any relaxation 23 of requirements to cope with double-ended guillotine breaks l
l 24 would be preceded by rigorous reexamination of the integrity 3
(
25 of heavy component supports under all design conditions, i
l l
, e. g - . - - s- - . . - ++- - 1 -
395 1 _ _ _ l'm not sure what that means.
[
k,,_ 2 Do you know what that means?
3 MR. SHAO: I think it essentially says heavy support 4 components should be maintained.
5 MR. BOSNAK: I tried to cover that a little bit this 6 morning. I would hope that it could be interpreted broadly 7 that if we got into things like trying to improve the 8 reliability of the heavy component supports, particularly that 9 have snubbers in their path, that the committee did intend '
10 that something like this could be included. ,
11 Basically we have in mind that we are not changing 12 the margin of the supports. But if we can improve the
( ) 13 reliability of the support system, we hoped that would be N./
14 included.
15 MR. SHEWMON: That was the sentence that we added at 16- Dave Okrent's advice or insistence. It wasn't in my original 17 draft.
18 part of the concern there, I am sure, was what we 19 were grandfathering. That is, it is fine for newer current 20 designs. What have we got that was designed 20 years ago that 21 is out there? Have we looked at that? And, 'are we changing 22 things?
23 It is not really what Carl brought up, in a sense l- e"s 24 it is what other sorts of things were there.
t 25 So, I think my off-the-cuff and personal opinion is l
t 396 1 if, you can show that you weren't reducing margins, and m.
I )
( ,/ 2 indeed, nothing had come as the toughness issue or other 3 things, that made you feel that- the margin here wasn't 4- adequate -- we are more sensitive to this, mostly because of 5 the Livermore study.
-6 MR. SH4O: I will give you some background. I
'7 think the Livermore study said the pipe rupture came f rom two
.8 causes. One was direct cause, one was indirect cause.
'9 MR. SHEWMON: We have read the report. Don't try to
- 10 tell us why we wrote the letter.
11 MR. SHAO: Heavy components were indirect cause.
12 MR. SHEWMON: Yes.
/ \ 13 MR. SIESS: I'm sure that all the work thev did on
! xj l 14 the indirect causes, was not presented to us at that meeting.
15 That was two years ago, and they have just finished up that.
16 work.
a 17 1 just got a report the last few months looking at 18 steam generators falling over and stuff.
19 MR. SHAO: I think it was presented to the l -.
l 20 subcommittee.
f 21 MR. SIESS: Which subcommittee? Metal Components?
i
[ 22 This one?
l l 28 MR. SH4O: If I r ememb er- it was --
gy 24 MR. SIESS: Okay, the full committee hasn't heard 25 that. Although it is mentioned in the letter that the greatest L
397 1 c.i sk was from the indirect causes. They looked at that, more.
,- m N, 2 But, A-2 and A-5 have been looked at and there could 3 be a follow up.
4 =A-4 and A-6 are BWRs.
5 MR. SHEWMON: I don't think there is any argument 6 with A-4s, certainly on the 3.16 and the 3.04 NG. That is 7' generally accepted. And'the 3.47, I've got on my notes the 8 jury is still out on'it.
9 MR. SIESS: And A-6 goes right along with it.
10 MR. SHEWMON: Yes.
11 Now A-5 you figure has been taken care of, since we 12 have that in the letter of report?
[ \ 13 MR. SIESS: No. It will come up again. It will
,\ wI
-14 'have to be covered.
'15 MR. SHAO: Mr Chairman, on A-5 I would Iike to 16 change the wording a little bit. Instead of saying seismic 17 and LOCA events in systems where LBB is~ applicable, it should 18 say decouple seismic and LOCA events when-specified.
19 MR. MICHELSON: That's what it says already.
20 MR. SIESS: Not on page 37.
21 MR. SHAO: In my slide, but in Volume 5, the word.ing 22 is different. In my Vugraph it is okay.
28 MR. MICHELSON: I agree with what is on page 87. l 24 don't agree with what is on your slide.
. 25. MR. SIESS: What does the slide say?
r ..
398 1 ., MR. MICHELSON: Well, the slide leaves out those g3
.( ,). 2 systems where leak before break is applicable.
3 MR. SHAO: When leak before break is applicable, 4 automatically you don't need to decouple it.
5 If somebody can prove the probably is very small to 6 have seismic and LOCA together, they can also be covered.
7 MR. SHEWMON: What is the' benefit of trying to do O this in two stages? It seems to me if you are going to look 9 at comment on the limited rule of.the leak before break, or
- 10 with the damping when the modified Rea Guide is there, vou can 11 look at it.
12 It seems to me vou are coina to have some trouble
- [' ) 13 in full committee buvino.a oia in a poke. Whereas, if you hm l -
14 have act the Rea Guide or something definite -then vou~ know 15 what it is you are buyinu, and the discussion will be easier.
16 MR. SIESS: We can easily take care of A-1, which is
/
17 --
that.is the broad-based rule, right?
18 MR. SHEWMON: It 'I s limited. Well, I would say it 19 is the limited rule.
20 MR. SIESS: l don't see pWR in there.
21 MR. SHEWMON: You are right.
22 MR. SIESS: A-1 is the broad-based rule, right?
28 MR. SHAO: Right.
- 24 MR. SIESS: And we can take care of that in two s ).
l "' 25 ' steps. We can comment on them, do it as a comment on the i
399 1 btoad-based rule.
' () 2 MR. SHEWMON: Broad-based rule isn't even written 3~ yet, is it?
4 MR. MICHELSON: Yes, it is.
5 MR. SIESS: That has gone to the Commission?
6 MR. ARLOTTO: No.
7 MR, SIESS: It hasn't. So, if we want to do it by 8 steps, as paul says, the broad-based rule as one item, we 9 decide when you want to comment on it -- that's your -
10 committee. Modified seismic damping values we can treat just 11 as a change to the Reg Guide in the usual manner, or referring 12 to Okrent's Committee on' Environmental as a Reg Guide change.
~( 13 The decoupling OBE and SSE is not ready, and that is
\
14 going to be a rule change. When the time comes, we will- look 15 at it.
16 A-4, paul says how can you be against it.
17 MR. SHEWMON: I don't think anybody here is going to 18 vote against it.
19 MR. SIESS: And A-5 and A-6. Maybe what we need to 20 do is just prepare a letter saying how we will comment on
~
12 1 this, and.which ones we have no further need to comment on, 22 which would probably be A-4, A-5 and A-6.
23 MR. MICHELSON: Certainly there is a problem. If 7-sp 12 4 A-5 is worded as it was in the Volume 5, I don't have a 25 problem. But, if he does put down "when justified," --
1
400 1 _,. MR. SIESS: Where did you see the "when justified"?
.rm( )-
' ( /.
- 2. MR. MICHELSON: On the slide. And he.says that is 3 the way it .-eally should have been written in Volume 5. tLw J
4 we will c omr.ien t on Volume.5 as it stands, and I won't have a 5 com4nen t .
6 If it is strictly when leak before break is 7 appilcable, fino becauco reactor water cleanup wil'1 not be 8 applienble at all as I would see it.
9 Go, which one are we comment on, Volume'5 or his 10- slido?
11 MR. SIEDS: Do you get the distinction he made?
12 Does it apply to the primary system or --
f6
{'s./-}- 13 MR. SHAO: Actually, there are cases in leak before 14 break where you can justify decoupling seismic and LOCA.
15 MR. MICHELSON: .I'm sure there are.
16 MR. SHAO: " Justify," we are not_ accepting a blank 17 check. The Applicant'has to give us a reason why they should 18 do i t.
19 MR. MICHELSON: The ACRS is giving you a blank check 20 .and saying, okay, go ahead until we have some further.
~
21 comment.
22 MR. SH4O: We have to go through a lot of study to 23 make sure you can justify to decouple.
g 24 MR. SIESS: At this point what do you think.ls I
~25 justified?
O wm _- . r -, . --m - ,-- - - - ..- -- - - - -
401 1 . . . . MR. SHAO: If the probability is something similar
( ~2 to what they'do in Livermore. .
3 MR. SIESS: At this point, for what systems has this
~4 been justified?
5 MR. SHnO: At this point right now on Westinghouse 6 primary system we can decouple.
7 MR. MICHELSON: That's all
, 8 -MR. SHf;O : And also the CE.
9 MR. BOGNAK: Right now we have completed the '
10 Westinghouse, the CE and the B&W loop, and that is it on the 11 probabilistic work done at Livermore.
12 MR. SIEGS: Now Carl,is willing to accept it for the
/m ) 13 Westinghouse, because you have read the documentation, or d
14 because you trust the Staff?
- 15 MR. MICHELSON
- Because i read the documentation.
16 (Laughter) 17 MR SIESS: So we-would be willing to say it is 18 justified for Westinghouse for what we have looked at, and if 19 similar results can be obtained for other plants --
20 MR.'MICHELSON: On a simiIar basis.
21 MR. SIESS: We can say that, right?
22 MR. MICHELSON: Yes.
23 MR. SIESS: It seems to me that the St.aff deserves
' ,f,3 24 some kind of a letter on the piping Review Committee work.
i- ('~')
25 For one thing, although the ACRS never does it, I think they
402 1 ought to be compilmented on the job they have done, and the
/~'N
( j) 2 reports they have gotten out. I think these are some of the a best reports I have read, some of the easiest reports to read 4 because the important stuff is up front,-and you can really 5 get it.
6 MR. SHAO: Thank you.
7 MR. SIESS: We could say la a letter, those parts 8 that we have previously looked at are satisfied, and h'ow we 9 would look at the implementation. -
10 We could agree with the recommendations with 11 certain minor caveats, and point out how we will'look at the 12 impiementation where the implementation involves more things.
}
. [V 13 For example, the broad-based rule, the language is 14 important for the Reg Guide, it is easy to look at with the 15 subcommittee that wants to go through that. I am sure they 16 will, rather than comina into the full committee with it.
17 So, I like that approach, paul. That is what vou 18 succested.
~19 Now, should the full committee hear anvthino of 20 this, an overview which can't be done in less than a few 21 hours?
22 MR. MICHELSON: I really think vou would have to if 23 vou want'them to cet a letter out in any reasonable fashion.
7, 24 You will have to.
25- MR. SIESS: Do vou think we could do somethina in
N.\ .
.c 3'
403
~1 about four hours?
f%
q_) 2 MR. MICHELSON: Hopefully it wouldn't take that 3~ long.
4 MR. SHEWMON: What parts would you have -- what-5 parts would you bring before them?
6 MR. SIESS: Something like the introduction, 7 backgroun'd and sort of a summary, and something _like Bosnak 8 gave us on the implementation, just so people understand some y; 9. of this. '
10 MR. MICHELSON: All members didn't receive all 11 volumes e i t her ',' I assume. I would assume --
12 MR. IGNE: No, not yet.
[ 13 MR'. MICHELSON: I would assume Volume 5 is all they
\
14 would need to see and use that as a basis for the 15 presentation.
.16 MR. SIESS: Have wo got any time _for the next 17 meeting? I gave Ray back three hours that were scheduled for 18 San Onofre.
19 MR. SHEWMON: If he hasn't spent it, you have got 20 enough there.
21 MR. IGNE: We have nothing on the schedule now.
22 MR. SIESS: San Onofre is off. I think we have got 28 three' hours.
. f-ss 24 MR. SHEWMON: So, it would be the ramifications of i
.. 25- leak before break; a little bit on -- you want to aim it
_L
404 1 pr,imarily on the recommendations that will be in the letter, fx i i
\ f. 2 or do you want to try to go over the summary of all five
.8 volumes?
4 MR. SIESS: I think they ought to go through the 5 five major recommendations and how they'are to be implemented, 6 so that the committee will have the background for what the 7 letter says about how we will review.
8 There should be some background on what we have 9 already looked at in the June 1988 letter. Discussion. A -
10 little bit.of the schedule on exemption, which followed form 11 the A-2 which vue talked about, what the broad-based does. And 12 that is in the future aways.
[ 13 Set the stage for a letter that says in general we NJ )
14 think the Piping Review Committee has done a good job.
15 And these recommendations we previously looked at 16 and agreed to. This we will look at under the rules and.so 17 forth.
18 MR. SHEWMON: So LBB for primary systems we will go 19 over, and a'little bit perhaps on the non-primary system part, 20 the' damping could be briefly done. Decoupling, ODE and SSE,
~
.21 what would you want-on that?
22 MR. SIESS: John can give us something. We have 23 John on that, John or Shao. I don't know which one had 4 2 4 .- that?
'~')' 25 MR. SHEWMON: It seems to me I would skip 3.04 and
405 1 take it by questions, if anybody has, so we could talk about
's_/ 2- what the tests are. But, decoupling, let's say we will take 3 that on questions.
4~ A-5, is that covered enough,.or do you want 5 background? This is seismic /LOCA decoupling.
6- MR. SIESS: That-was the thing we discussed.:We need 7 some background on what we went through.
8 MR. SHEWMON: What is justified and what is 9 applicable.
10 MR. MICHELSON: What the scope of this is going to
-11 be.and where they are going to draw the lines, how they are 12 going to handle the situation.
'l 13 MR. SHEWMON: So A-5 we get then.
NY 14 What about A-67 A-5 was decouple seismic /LOCA.
t
.15 MR. SIESS: They need to start off with the June 16 letter and bring them-a little up to date qn.the incorrect 17 clauses.
18 MR. SHEWMON: Leak detection requirements.
19 MR. MICHELSON: You need some discussion of that, 20 just so they rea l i:ce that is a part of the fix.
21 MR. SHEWMON: T's2 ? probab l y should be grouped with 4
22 the leak before b r e a by Idn't it?
23- MR. MICHELwCN: (e s , that is where it logically, I
~
-s 24 would think, belongs.
'\~)
~
25 MR. SIESS: That's the way it was presented
f ~
406 1 yesterday.
,O
( ,) 2 We really need to separate the PWR/BWR. There is a 3 different set of caveats on the PWR. I think it makes it 4 easier to think about.
5 MR. SHEWMON: Do you have that all so we can lay it' 6 out now?
7 MR. IGNE: Yes. We alve the full ACRS Volume 5. a 8 backaround documents we start off with the June 1983 letter 9 then we go leak before break with the leak detection s then we-10 discuss dampings the OBE/SSE 3 3.04 3 3.16. We answer that by 11 question.
12 MR. SHEWMON: You may want to break damping down.
.- [~') 13 MR. SIESS: Put the damping and the decoupling L./
14 together at the end. They are different categories. Neither 15 of those involves fracture mechanics--- I'm sorry, the 16 decoupling does. The damping is a separate. item, it doesn't 17 involve the fracture mechanics study and the decoupling does.
18 MR. SHEWMON: So you have got the LBB leak detection 19 _as one significant component; and the other one is the 20 decoupling damping.
21 MR. SIESS: LBB for a boiler involves everyt'hing 22 that-the PWR ' involved, but also involves the replacement of 23 the leak detection, right?
,g 24 MR. SHEWMON: It is not. clear what LBB on the boiler '
'~
25 -- that there is even anything about LBB on the boiler.
l
I 407 l 1
i 1 _ , .
MR. SIESS: Broad-based rule includes everything?
q
, , ) 2- MR. SHEWMON: No, it doesn't. It explicitly 3 excludes things like t he bo i l er- tha t has stress-corrosion 4 . cracking.
5 MR. .MICHELSON: .Unfortunately, it does not. We 6 never got into all the detail. The words don't seem to exclude 7 it anywhere.
8 MR. SHEWMON: They certainly do. If you turn-to 9 page 28 --
i.
10 MR. MICHELSON: The recommendation of the-committee 11 does. I thought you were talking about'the rulemaking 12 document. In the rulemaking document, I don't find, for
/ I 13' instance, that caveat.
.kj 14 MR. SHEWMON: Then we get back to the short rule 15 which is PWRs only.
16 MR. MICHELSON: Yes.
17 MR. .SHEWMON: And the report which says they clearly 18 want to exempt boilers. And I think that.is again the problem 19 with t'r y i ng to cope with the general rule at this time.
20 MR. MICHELSON: It is not supported by any of these 21 five volumes that deal with it.
22 MR. SIESS: What i .said is, if we inspect and review 23 the broad-based rule later. What we need as a presentation, 24 is enough for the full committee to know why we want to review
.b /
t
'~# 25 it later.
1 408 1 _ . . MR. SHAO: For,the BWR, suppose they place new
/~%
~( i ,
(_) 2 material, suppose they put in water chemistry. Now they say 3 they want to have leak before break. In that case, the boiler 4 will be also applicable.
5 MR. SIESS: That's what I thought.
6 MR. MICHELSON: It is not supported though by the 7 review committee.
8 MR. SHAO: When justified.
9 MR. MICHELSON: That's where we get into a problem, 10 because you are extrapolating beyond what this piping Review 11 Committee seemed to be telling me.
12 MR._SHEWMON: No, it is not. It says if it is not'
/~*\
( ; IS sensitive to stress -- if it is stress sensitive, then LBB
~s 14 doesn't work. And he is saying, okay, if you take the'other 15 side of that same coin, if it is no longer sensitive, then it 16 does.
17 MR. MICHELSON: If it is no longer sensitive.
18 MR. SIESS: That's what I was trying to say for the 19 boiler, A-4 and A-6 are requirements for leak before break.
20 Right?
21 MR. SHAO: Yes.
22 MR. BUSH: I think though --
this.ls a hypothetical 23 one -- it would seem to me since there is a review on this, rx 24 looking at it in a probabilistic fracture mechanics point of ks./
25 view, that probably one would want, you might say, the jury to
409 1 come back in before you make any such decision, (q
x_/
2 Hypothetically you could do it.
3 MR. SHEWMON: You mean we are sending LBL another X 4 million dollars to do fatigue growth curve on stainless steel 5 now?
6 MR. BUSH: Stress corrosion effect. Correct. That 7 report is in draft form richt now. The work has been pretty 8 much done. It is not new work.
9 MR. SHEWMON: They are coina to plav merry heck 10 finding out how fast a 3.16 nuclear grade would go, although i 11 guess they could find some data on it.
12 MR. BUSH: No comment at this stage of the game.
18- MR. SIES3: Getting back to leak before break, the
% ,/
14 interim rule of the schedule exemption says for pWR primary 15 loops, the Staff has gone ahead on'the basis of our 1989 16 letter proposing to go ahead and eliminate-leak before break 17 for pWRs primary loop. ,
18 The Staff is working on another rule which does two 19 things; it would extend leak before break to boiling water 20 reactors if they have replaced the piping and if they have-21 more stringent leak testing requirements.
22 The broader rule would also extend leak before 28 break to other than primary systems. Right?
r- 24 MR. SH4O: If they are justified.
v
, 25 MR. SIESS: If it can be justified on a basis
410 1 s,i_m i l a r to that, and considering systems, et cetera, et
- p i
Av) 2 cetera.
3 And that rule requires a lot more looking at when it 4 is extended to other systems, and it may require more looking-5 at when it is extended to boilers, I say may.
6 Now to me, that approach covers.A-1, A-4, A-6 fairly 7 straightforward.
8 Now A-5 you can toss in next, because that was
- 9 addressed in the previous letter. We have had reports on it.
- 10 The subcommittee has heard the indirect cause stuff.
11 Then modified seismic damping is a.complutely 12 separate thing not involving fracture mechanic studies.
18 And the decoupling OBE/SSE is something that is so
]
14 far down the line. It will certainly be looked at by other
.1 5 subcommittees.
.1 6 I would take them about like t h a t, . And then we can 17 write a letter saying essentially what we are going to do with 18 it.
19 Okay, does that sound reasonable?
20 MR. SH40: Yes.
21 MR. SIESS: Now, does it sound reasonable to 22 adjourn?
28 (Whereupon, at 12:30 p.m., the hearing was 24 adjourned.)
4
\
25 4
- . . - . . ~ , , . . , , . - - . . - . . .- n- - ,w -, --n-,, . - - , - , . ,
1 CERTIFICATE OF OFFIClhL REPORTER 2
3 4
5 This is to certify that the attached proceedings 6 before the United States Nuclear Regulatory Commission in the 7 matter of: Advisory Committee on Reactor Safeguards 8 '
9 Name of proceeding: Combined Meeting of ACRS Subcommittees on Metal Components and Structural to Engineering 11 Docket No.
12 piace: Washington, D. C.
18 Date: Friday, May 24, 1985 14 15 were held as herein appears and that this is the original 16 $
transeript t h e r e o.f for the file of the Unitad States Nuclear i 17 Regulatory Commission, t
13 :p (Signature) . . ,( ., .
(Typed Name of Reporter) d I\((
, f)~~
Mimie Meld.zer 20 21 22 23 Ann Riley & Associates, Ltd.
24 25
'^~
^
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ACRS 5/24/85 RJB0SNAK NRR/DE PRC TECHNICAL RECOMMENDATIONS STATUS IN LICENSING REVIEWS o WRC BULLETIN-300-DAMPING AND SPECTRA ,
~
PEAK SHIFTING o DECOUPLING SSE & LOCA .
CE A-2 PLANTS o GDC 4 LIMITED EXEMPTION - PWR LOOP
. EQUIPMENT QUALIFICATION ,
. HEAVY COMPONENT SUPPORT INTEGRITY ACRS LETTER 6/14/83
. STRUCTURAL DESIGN o ARBITRARY INTERMEDIATE BREAKS ENVIRONMENTAL QUALIFICATION FOR NON DYNAMIC EFFECTS OF NON-MECHANISTIC ,
BREAK WITH GREATEST CONSEQUENCES O
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O O O ISSUES TREATED 0 EVENT COMBINATIONS i
P0TENTIAL SIMULTANEOUS OCCURRENCE OF EARTHQUAKES WITH PIPE RUPTURES AND OTHER DYNAMIC LOADS SUCH AS WATER HAMMER, SAFETY RELIEF VALVE DISCHARGE, TURBINE TRIP AND VIBRATORY LOADS. ,
RESPONSE COMBINATIONS.
METHODS FOR EVALUATING THE PERFORMANCE OF MULTIPLY SUPPORTED PIPING WITH INDEPENDENT INPUTS.
O STRESS LIMITS AND DYNAMIC ALLOWABLES INELASTIC ALLOWABLES AND STRAIN RATE EFFECTS, 0 WATER HAMMER LOADING CODE AND DESIGN SPECIFICATIONS FOR WATER HAMMER, O PIPING VIBRATION LOADS EVALUATION PROCEDURES F0R ESTIMATING OTHER THAN SEISMIC VIBRATORY LOADS,
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0 B0B GUENZLER, INEL 0 BOB KENNEDY, SMA 0 EVERETT RODABAUGH, E. C. RODABAUGH ASSOC.
0 .AL SERKIZ, NRC 0 JOHN STEVENSON, J. D. STEVENSON & ASSOC.
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- 1. EVENT COMBINATIONS 0 -FOR MECHANICAL DESIGN, DEC00PLE EARTHOUAKE (SSE AND- !
OBE)-AND PRIMARY' SYSTEM DOUBLE-ENDED PIPE BREAK FOR WESTINGHOUSE-AND COMBUSTION ENGINEERING (BABC0CK AND WILC0X ADDED SUBSEQUENT TO THE PUBLICATION OF NUREG-1061, VOL. 4) . DEC00PLE.EARTHOUAKE-(SSE-AND .
~
OBE)~AND PIPE BREAK IN ANY OTHER PIPING SYSTEM WHEN ADEQUATE-TECHNICAL-EVIDENCE-IS PRESENTED.
0 ANTICIPATED. DYNAMIC LOADS SUCH AS WATER HAMMER, SAFETY-RELIEF VALVE DISCHARGE, TURBINE TRIPS, AND VIBRATORY LOADS SHOULD BE COMBINED WITH EARTHOUAKES-(SSE AND OBE).
- 2. RESPONSE COMBINATIONS
- O THE INDEPENDENT SUPPORT MOTION RESPONSE SPECTRUM METHOD
! .SHOULD BE ALLOWED AS AN OPTION TO THE PRESENT UNIFORM-I SUPPORT MOTION PROCEDURES. THE METHOD AD0PTED BY THE I
] } {i RECOMMENDED REGULATORY CHANGES (CONTINUED 1 STAFF ALLOWS SRSS COMBINATIONS BETWEEN DYNAMIC AND PSEUD 0 STATIC COMPONENTS OF RESPONSE, WHICH RELAXES THE !
PRESENT REQUIREMENTS OF ABSOLUTE SUMMATION. MORE0VER, A LESS CONSERVATIVE RULE IS USED FOR COMPUTING THE PSEUD 0 STATIC RESPONSES. ALSD, A NEW RULE FOR COMBINING HIGH FREQUENCY MODES IS INTRODUCED WHICH REFLECTS GREATER ,
REALISM.
- 3. STRESS LIMITS AND DYNAMIC ALLOWABLES 0 A MAJOR SHIFT TO INELASTIC ANALYSIS OF PIPING SYSTEMS USING STRAIN LIMITS FOR PIPING ANALYSIS IS NOT JUSTIFIED AT THIS TIME. N0 CHANGE IS RECOMMENDED IN THE PRESENT SRP PROCEDURE, WHICH ALLOWS INELASTIC i PIPING ANALYSIS ON A CASE-BY-CASE BASIS.
1
. O THE SRP SHOULD ALLOW INCREASES IN DESIGN YIELD STRENGTH GREATER THAN 10 PERCENT DUE TO STRAIN RATE EFFECTS FOR l PIPE-WHIP RESTRAINT DESIGN WHEN SUPPORTED BY TECHNICAL j EVIDENCE.
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O O O RECOMMENDED REGULATORY CHANGES (C0_N_T.INREDl-11 . WATER HAMMER LOADI_NG
'i 0 EFFORTS TO REDUCE OR MINIMIZE THE INCIDENCE OF ACCIDENTAL WATER HAMMER (WITH EMPHASIS ON OPERATOR TRAINING) SHOULD CONTINUE, O DEVELOPMENTOFDESIGNSTANDARDSFORWATERHAMNERSHOU[D REST WITH THE PLANT OWNER OR APPLICANT AND HIS DESIGNER, AND NOT WITH THE NRC.
.E
!' 0 WHILE STANDARD CHECKLISTS COULD'BE USEFUL, THE WIDE VARIETY OF PLANT DESIGNS!AND OPERATIONS' WORKS AGAINST D5VELOPMENT OF SUCH CHECKLISTS AND THE;NRC SHOULD NOT l BE CALLED UPON TO DEVELOP CHECKLIST' S AT THIS TIME.
l
- 5. PIPING VIBRATION LOADS j 0 FOR VIBRATORY LOADS OTHER THAN SEISMIC IAND WITH SIGNIFICANT LOADING IN THE FREQUENCY RANGE FROM 33 T0 i 100 HERTZ, IT IS ACCEPTABLE TO PERFORM NONLINEAR
-ANALYSIS TO ACCOUNT FOR GAPS BETWEEN PIPES AND PIPE i SUPPORTS, I i ;
- i o o o i
j RECOMMENDED REGULATORY CHANGES (CONTINUED 1 0- THE SRP SHOULD ALLOW:AND ACCEPT THE CONDUCT OF
. VIBRATION TEST PROGRAMS IN ACCORDANCE WITH ANSI /ASME -!
j OM3, " REQUIREMENTS FOR PREOPERATIONAL AND INITIAL j- - START-UP VIBRATION TESTING 0F NUCLEAR POWER PLANT
~
j PIPING SYSTEMS." ;
i 0
l EXPLICIT REFERENCE TO VIBRATIONAL LOADS FROM l RECIPROCATING AND ROTATING EQUIPMENT SHOULD BE MADE IN_
! THE SRP. ,
1
! O THE SRP SHOULD INDICATE THAT IT.IS' ACCEPTABLE TO l PERFORM THE EVALUATION OF VIBRATORY LOADS TRANSMITTED 1 i BY SUPPORTING STRUCTURE TO PIPING'BY ANALYSIS, TESTING,
! 0R-A COMBINATION OF ANALYSIS AND' TESTING.
I i
L l
4
O O di. ~
i RECOMMENDATIONS FOR RESEARCH l (NOT SORTED _BY ISSUES) 1 1
l 0 COMPLETE WORK ON BABC0CK AND WILC0X (COMPLETED SINCE -
PUBLICATION OF NUREG-1061, VOL 4) AND GENERAL ELECTRIC REACTOR COOLANT SYSTEMS TO LEARN IF IT IS POSSIBLE.T0 j DECOUPLE EARTHOUAKE (SSE AND OBE) AND RCL~ PIPE RUPTURES FOR,,
j THESE VENDORS.
,0 UNDERTAKE TESTS 0F FLAWED (DEGRADED) DUCTILE PIPING SUBJECTED TO SIMULATED SEISMIC.AND OTHER DYNAMIC LOADS, SUCH AS WATER HAMMER AND FLOW INDUCED LOADS, IN ORDER TO ESTIMATE l DESIGN MARGINS.
O ADDITIONAL ANALYTICAL STUDIES SHOULD BE PERFORMED T0:
! 1. CLARIFY THE IMPACT OF PHASE CORRELATIONS BETWEEN SUPPORT GROUPS ON THE RECOMMENDATIONS FOR THE l
INDEPENDENT SUPPORT MOTION METHOD, l
i
- 2. EVALUATE METHODS FOR CALCULATING THE EFFECT OF CLOSELY SPACED MODES, AND I
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O O O p RECOMMENDATIONS FOR RESEARCH (CONTINUED)
! .(NOT SORTED BY ISSUES) i .
- 3. ESTABLISH THE TRANSITION FREQUENCY BETWEEN llIGil AND LOW !
1 FREQUENCY WilEN IMPLEMENTING Tile ALGEBRAIC SUMMATION-l RULE FOR llIGil-FREQUENCY M0DAL COMBINATIONS, l
0 IT SHOULD BE DETERMINED WilETilER THE RECENTLY APPROVED PVRC PIPE DAMPING VALUES FOR SEISMIC LOADS CAN BE EXTENDED-T0 i HIGHER FREQUENCY (33 TO 100 HERTZ) VIBRATORY LOADS.
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. VOLUME 5 f
SUMMARY
- NRC PIPING REVIEW COMMITTEE.
E CONCLUSIONS AND RECOMMENDATIONS 8
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MAY 2ti,1985 O
3 f Y VOLUE-5
SUMMARY
- PIPING REVIEW COMMITTEE CONCLUSIONS AND O RECOPPENDATIONS o PRC REVIEWED TASK GROUP REPORTS o REVIEWED COPPENTS RECEIVED ON TASK GROUP REPORTS FROM NRC MAJOR OFFICES o SUMMARIZED MAJOR ISSUES o PREPARED SET OF RECelfENDATIONS FOR REVISING NRC k
] REQUIREMENTS - CATEGORIZED BY PRIORITY AND RANK .
Y 9- o PREPARED SET OF RECOMMENDATIONS 'FOR RESEARCH CATEGORIZED BY PRIORITY AND RANK CONCLUDED o SUGGESTED CHANGES SUBSTANTIAL
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o.SHOULDHAVEPOSITIVEEFFECTONLICENSINGPROCESS'lSAFETYl AND RELIABILITY
! o MAY REQUIRE CHANGES TO RULES'l REG GUIDES'l AND STANDARD REVIEW PLANS o MAJOR CHANGE IN ASME CODES l
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S M ARY OF REC 0fmEWAT10NS Category &
Rank Order Recommendation Documents J
lequiringChange A-1 i
(Vol.3) Use leak before break LBB) rather than the 10 CFR Part 50 DEG8 so that terminal would be eliminated when certain acceptance a(nd fntemediate-breaks (Ap GOCpendix A, criteria are met. It would lead to exclusion 4,-30, ofdynamiceffectssuchaspipewhip* jet -32)
-31,3.6.2 impin SRp tion.gement,The naand subcompartment press,uriza- R.G. 1.46 Design Criterkior on 4 impact would be on General i
Miss'le Design Bases. _ Environmental and Ine requirement to postu-late aroitrary intermediate breaks should be '
eliminated.
A-2 Modify seismic dampin; values currently used R.G. 1.61 (Vol.2) in sensaic design. Tae suggested values have SRP 3.9.2
! been incorporated into A5ME-III and accepted
. by NRR on a case-by case basis. This modift- ,
. cation could lead to changes in support design and spacing and consideration of
- nozzle loads as well as reducing the number of snubbers. -
(Vol.2) 10 CFR Part 100 -
~ (AppendixA) i
' A-4 (Vol.1) Re lace 31655 or 30455 in BWR recirculation 10 CFR Part 50 pi ing with alloys resistant to IGSCC to el ninate this mode of pipe cracking. (AmendixA Possible types are 316NG, 304NG, 347NG.
GD:-30(poss,ibly))
NUREG-0313 R.G.' 1.44 A-5 Decouple seismic and LOCA events when
-(Vol.4) . justified.. SRP 3.9.3 A-6 Modify leak-detection requirements. This
{
(Vols.1,3) issue impacts BWR-IGSCC as well as Recos- NUREG-0313 mendation A-1. Tech. Specs.
R.G. 1.45 9
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i-l . ARNMUtY OF REtemEWATIONS FOR RESEARCH l
[ 4ategory &
,, Rank Order - 4eceamendation I A-1 The full-scale pipe fracture experiments of the NRC Degraded s (Vols.l.3) piping program should be completed. Of primary interest is the development and/or validation of fracture mechanics analysis l techniques for ductile piping. Experimental variables should ,
include flew geometries, esterial toughness, extal-to-bending .
load ratios, and static / dynamic loads. j i
Development of advanced techniques and procedures for crack A-2 (Vol.1) detection and depth sizing should continue for incorporation ;
into Code requirements. Included should be analysis of the ,
human fact' o r, equipment qualification and certification, and i inspectiontechniquesfordetectinganddimensioningflaws 5 in pipes repaired by the weld over ay process.
. . t A-3 Test programs (e.g., EPRI's piping capacity tests) for verify- !*
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(Vols.2,3) ing seismic design margins and identifying failure modes for
, . typical piping systems should be supported. Test results i
) i should,be evaluated and recommendations provided for criteria ;
?- changes (e.g.3)pelassification of seismic as " secondary , as appropriate. Both crackedinertialand uncracked stresses v
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[} piping sysgans should be tested.
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- A-4 Work under way at the Lawrence Livemore National Laboratory .
(Vol.4) on Babcock and Wilcox and General Electric reactor coolant 3 loop piping should be completed to learn whether earthquake in 4
i combination with reactor coolant loop double-ended guillotine ;
break may be excluded for these designs.
A-5 Work should be performed to detemine the reliability of (Vol.3) methods to predict leak rate and validate the reliability of leak-detection systems.
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