ML20212E166
| ML20212E166 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 02/25/1987 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 8703040284 | |
| Download: ML20212E166 (110) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION i
i l
Title:
Briefing on Surry Incident (Public Mooting) 1 1
1 Location: Washington, D. C. ,
I Date: waancaday, February 25, 1987 i
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Pages: 1 - 82 i
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i Ann Riley & Associates Court Reporters 16251 Street, N.W., Sulte 021 l Washin0 ton, D.C. 20006
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(202) 203-3050 l 0703040204 07022D pl)it 10CFil l
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- 6 This is an unofficial transcript of a meeting of the 7 United States Nuclear Regulatory Commission held on a 2/25/87 .. In the Commission's office at 1717 H Street, 9 'N.W., Washington, D.C. The meeting was open to public 10 attendance and observation. This transcript has not been 11 reviewed, corrected, or edited, and it may contain
.f .
- .g 12 Inaccuracles.
13 The transcript is intended solely for general 1
14 Informational purposes. As provided by 10 CFR 9.103, it is 1
15 not part of the formal or informal record of decision of the 16 matters discussed. Expressions of cpinion in this transcript' 17 do not necessarily reflect final determination or beliefs. No te pleading or other paper may be filed with the Commission in 19 any proceeding as the result of or addressed to any statement 20 or argument contained herein, except as the Commission may ,
l 21 authorize.
i 22 i
23 i
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25
- )jl 1 1 UNITED STATES OF AMERICA 2 NUCLEAR REQUIATORY COMMISSION 3 -----
4 Public Meeting
- 3 _____
6 BRIEFING ON SURRY INCIDENT 7
8 -
Wednesday, February 25, 1987 9 1717 H Street, N.W.
10 Room 1130 11 WaLhington, D.C.
, 12 13 The Commission met in open session at 10:00 o' clock 14 a.m., pursuant to notice, the Honorable Lando W. Zech, Jr.,
15 Chairman of the Commission, presiding.
16 17 COMMISSIONERS PRESENT 18 Lando W. Zech, Jr., Chairman 19 Thomas M. Roberts, Commissioner i
20 James K. Asselstine, Commissioner 21 Frederick M. Bernthal, Commissioner 22 Kenneth M. Carr, Commissioner 23 24 l 25
1' 2 l'
1 STAFF PRESENT AND SEATED AT COMNISSION TABLE 2' J. Taylor 3 V. Panciera 4 R. Vollmer 5 R. Bosnak 6 B. Sharon 7 AUDIENCE SPEAKERS:
8 3. Stewart 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
. /> 3 l V
1 PROCREDINGS
. 2 CNAIRMAN 3ECNt Good morning, ladies and gentlemen. ;
3 Commissioner Asseletine and commissioner Bernthal-i 4 will be joining us shortly. j t
- 5 on the 9th of December, 1986, the Surry Plant ,
, 6 experienced a condensate piping failure which resulted in a p 7 tragic loss of life. The event raises questions about the i 8 balance-of-plant piping systems and the safety implications of ,
9 failures of these systems. l 1
4 10 The NRC Staff is here today to brief the cosaission ;
i 11 on the results of the augmented inspection team activities at I- 12 Surry. The briefing will include ths response to the event, l
4 7 13 and the implications of the event.
I^ .
I 14 I understand that Virginia Power has conducted their !
l 15 own investigation of the event, and they have held public [
i J 16 briefings in a number of cities to share the lessons to be !
. ' 17 learned from the accident with the industry. ;
[ 18 Virginia Power Company reports have been distributed j i .
l 19 to the public, and are a valuable case study.
l 20 The staff will address the accident from the !
21 regulatory perspective, and will provide insights that we as j 22 Commissioners will consider regarding the maintenance and ,
j 23 operations of balance-of-plant systems. l t
l i 24 Do any of my fellow commissioners have opening
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} l remarks?
25 ;
.. j
,$ 4
/
1 COMMISSIONER ASSELSTINE: No.
2 CHAIRMAN ZECH: Mr. Vollmer, will you proceed, 3 please.
4 MR. VOLLMER: Thank you, Mr. Chairman.
5 This morning we have Vince Panciera to my right, who 6 led the augmented inspection team to the site after the 7 incident; Bob Bosnak to my left, one of our principals involved 8 in the follow-up, and working with the implication; Brian 9 Sheron to my left; and of course Jim Taylor.
10 What I would like to do on the overview slide is to .
11 give you very briefly a chance to preview some of the topics 12 that we will be covering this morning.
13 second slide, please.
14 First of all, as you know, the response in the short 15 term was to send immediately an augmented inspection team to 16 the site, which was headed by Vince. An Information Notice 17 was prepared by I&E very quickly to alert other utilities, 18 encourage their inspection of erosion-prone areas in their own 19 piping. We will get into the number of utilities that did 20 respond to that, and some of those results, a little bit 21 later.
22 We also put together an experts' meeting to assess l 23 surry and similar experience. We called our own consultants, 24 we called the code people in, industry experts, insurance 25 people, and the goal of the above activities was to determine
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! 1 as soon as possible if we saw a need for any immediate action.
2 And as you will find, we concluded that there wasn't need for 4
3 an immediate action, but we were preparing the scene for a 4 longer term action.
[ S Under Implications, I think the implications this 4 immediately hit us with was, first of all, whether this would 7 need or undermine the GDC-4 broad scope rule change which we j 8 have underway, which would really eliminate the need to -
i
,. 9 consider pipe rupture for a large class of pipes in nuclear 10 plants. That is an important initiative, something the staff
{ 11 has been working on for a long time, and at first blush this j 12 would raise a question about undermining that.
l 13 It also, as you point out, Mr. Chairman, raises the 14 question of the degree of attention we need to give to the 15 balance of plants and thirdly, it will need to explore this in Q
[ 16 terms of longer term the life extension areas, because this j 17 clearly is a time-related incidents and also it, as you will i
18 find out, calls into question our handling of other certain 19 activities. For example, generic safety issues on system 20 interaction, things of that nature, which this had some
! 21 interesting side effects, which is my next bullet.
}
22 The Side Effects of the steam from this incident set l
l 23 off various water, halon and co-2 fire suppression systems l
24 which caused problems with electrical cabinets. Some co-2 got 25 into the control room and, of course, this is -- protection of
. 6' D'
I the operators in any type of event is a very important thing, 2 and it also set off some of the -- interfered with the security 3 card reader, so that access to the plant was made more
. 4 difficult.
5 In the long term, the response is we need to look at 6 the safety issues, both the immediate pipe break issue itself 7 and its effect on balance of plant, and effect carrying on to O the primary system, and also look at its effect on peripheral 9 issues, which this did influence.
10 We intend on having additional generic 11 communications, we intend on having workshops, and our goal 12 then is to define the parameters with which we think there is 13 a potential for a corrosion problem, and focusing on piping 14 configurations, material, water chemistry, and fluid dynamics, is and to see what regulatory action we need to take. And we are is looking at hopefully a couple of months to make that decision.
17 And lastly, the coordination. The people we have 18 had involved in this activity beside ourselves are national 19 laboratories. EPRI and INFO have been involved, ASME, the 20 code people, are involved; the insurance companiest I have 21 been in touch with foreign experts in eliciting their help 22 and, of course, Virginia Power has done a great deal of work 23 on their'own and conducted their own workshops.
24 What I would like to do now, Mr. Chairman, is turn 25 it over to Vince to give you the event overview.
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1 CHA230 TAN SECM Fine. Thank you. kroceed.
-2 NR. PANCIE3tA: This morning I would li e to cover j 3 four particular aspects of'the surry Unit 2 'pipW rupture '
4 event.
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First, I would like to discuss the event ove'eview/
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e including plant conditions and description of the toedwater -
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7 system, the initiating event that caused N ihe initial scram,
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3 e and a general description of the pipe ruptul's. l'
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9 The second area I would like to discuss the atiquesnted :
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10 inspection team activities, including our initial responese . ,r-<
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!, 11 activities following the event, and addit' tonal inspect' ions ,
7 .
.rl 12 conducted during a five-week period following the event. ,
' f 13 Thirdly, I would like to cover three systens for ,
. r 14 equipment malfunctional one that initiated the' event, one that 7 d
15 possibly contributed to the additional release of water n. /i
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i 16 following the rupture, and one that resulted in water' intrusion, ,
j 17 into the fire protection centrol panel that resulted after thM'
, t 18 rupture.
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- 19 Lastly, I will briefly discuss station recovery.F "-
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{ 20 Next slide, please.
I ,
21 The main feed system rupturn on Unit 2 began in the !
22 afternoon on December 9th. Both units were operating at 100 l 23 percent power. Unit 2 had completed a refueling r,ntage. i 4
l 24 There was some ongoing work in the vicinity of the feed pumps; ;
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l 25 namely, lagging and piping and some work on instrument lines.
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And there were personnel in that immediate vicinity.
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, Ths system in which the rupture occurred was the y 3 conden'este.feedwater system. The plant is a three-loop ;
4 , pressurised water reactor, and there were three condensate
's / pumps that take suction on the hotwell. This plant does not- ,
h6 have condensate booster pumps.
l 7 ,, The feed pump, condensate feed pumps deliver feed at !
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' 8- about 370 pai to a 24-inch condensate header through a series
, 'O of feedwater heaters. The condensate header in turn then j
feeds the two main feed pumps --
10
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, a k'NI 11 C090tISSIONER ASSELSTINE: Actually it would be
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! ., ' 12 helpful if you used the aika and sort of walked us through the i
p i
!, 13 y diagram.
, i i 14 MR. FAFCIERA: Yes, sir.
7 15 C000tISSIONER ASSELSTINE It would be helpful to me, ;
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i 16 4 p ay.
17 CHAIlotAN 2ECH: I think that's a good idea. j,
, 18 ColetISSIONER ASSELSTINE: Because our copy wasn't l l ,'n all that great to start with.
i '
l 20 CHAIRifAN ZECNt Not very good on the screen, either, l
21 but I think it will help if he walks us through it.
l 22 MR. PANCIERA Ne have the condenser -- we have a h conderiser hotwell right below the condenser.
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23 Ne have three i i t
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l-24 condensate pumps taking suction on the hotwell. The condensate 25 then is passed through polishers, through a series of feedwater l s ., ;
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1 heaters, and then into this"large 24-inch pipe which I call the L 2 condensate header.
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3 From the condensate header, you have two takeoffs.
4 One. going to each of the feed pumps. Here is the condensate 5 header, here is_the fadd pump (indic'ating). Here is one feed 6 pump, here'is the second feed pump. The A feed pump was where 7 the rupture occurred.
l 8 The feed then goes through the last point of your ,
9 heaters, and then into each individual steam generator-through. ,
10 another header.
11 3 The insert here shows the 24-ir.ch header. It shows l 12 a straight piece of pipalcoming off that header, and there is 13 an albow, a sharp albow, and then there is a straight piece of 14 pipe.
15 This piece of pipe then takes it down to the feed 16 pump suction.
17 While I am up here, the fracture occurred right here 18 (indicating). This line takes off on the cc:idensate -- the 19 line that feeds'the=Euction through the feed pump, when the 20: rupture occurred, this line moved over in a rotational 21 direction and hit the discharge piping on the feed pump.
22 Does anyone have any questions on that?
i 23 CHAIRMAN ZECH: Where was the check valve that was 24 ' involved? Can you point out?
25 KR. PANCIERA: There were two valves involved. Let i
.a _ _ _ . - _
l
- 10 l
l 1 me point out both. We have the main steam trip valve which 2 basically is the same thing as the main staam isolation valve, 3 serves the same function. It's called by a different name and i
I 4 has a slightly different principle of operation.
)
l 5 And then we have the feed pump discharge checks, '
I 6 which are right here. Those are the two systems or the two l 7 pieces of components that malfunctioned during this event.
8 CHAIRMAN ZECH: Point them out again, please. The 9 malfunction. l l
l 10 MR. PANCIERA: This is the main steam trip valve I 11 which has steam going off, then going to the main generation 12 unit.
l 13 CHAIRMAN ZECH: That malfunctioned?
14 MR. PANCIERA: That's what caused the reactor to 15 scram.
16 CHAIRMAN ZECH: Right. Okay.
17 MR. PANCIERA: And then this malfunctioned, because 18 the internals of this check valve permitted free communication 19 between the upstream and the downstream side, and therefore 20 may have contributed to the amount of water that then came out 21 this break.
.22 CHAIRMAN ZECH: All right. Thank you.
23 COMMISSIONER ROBERTS: Is this piping covered by the
! 24 ASME Code?
l 25 MR. PANCIERA: It's not covered by Section 3, but t
'l> 11 1 I'm sure it's covered by the ASME Code.
2 MR. BOSNAK: It's covered by B31.1. The piping was
, 3 designed to B31.1, which is the -- it met B31.1. There is no 4 third party inspection required in that B31.1. So it's 5 different than the ASME Boiler and Pressure Vessel Code.
6 COMMISSIONER ROBERTS: Well, you will have to 7 educate me. What is B31.1?
8 -
MR. BOSNAK: B31 is the code for pressure piping, 9 and there are a number of series. 31.1 is power piping. It 10 goes on to cover refrigeration piping and gas transmission 11 piping, chemical plant piping, refrigeration piping. 31.1 is 12 the --
13 COMMISSIONER ROBERTS: But that's an ASME Code 14 standard?
15 MR. BOSNAK: It's an ASME Code standard, but it's 16 not --
17 COMMISSIONER ROBERTS: No third party inspection is 18 --
19 MR. BOSNAK: It's not under the aegis of the Boiler.
20 and Pressure Vessel Code.
21 COMMISSIONER ROBERTS: Okay. Thank you.
22 MR. BOSNAK: It's just a standard.
23 MR. PANCIERA: As I mentioned previously, the 24 reactor trip occurred because of the spurious closing of the i
I 25 C-loop main steam trip valve. The main steam trip valve
[J' 12 si 1 closure was caused by a combination of low instrument air and 2 an improperly assembled valve. I will get into that a little 3 bit later and explain the details of that. I have a schedule 4 for that.
5 The plant tripped on low-low level in the C steam l
I 6 generator at about 2:20 p.m. on the 9th. About 30 seconds 7 after the trip, the rupture occurred. The first indication of i
8 the rupture was a hissing sound. This was heard by the
! 9 operators in the vicinity of the control rod.
10 The first indication was a hissing sound, and about 11 four seconds later it was followed by a loud noise. Both feed 12 pumps tripped on low suction pressure after the rupture, so 13 both feed pumps tripped.
14 The primary system responded in a normal manner.
l 15 The operators entered the emergency procedure sequence and 1
16 secured all secondary piping. Auxiliary feed initiated 17 automatically. The operator response, we felt, was very 18 good. The operators responded in a very good manner. All 19 systems actuated as expected. There were no technical 20 specification violations that were exceeded, and there was no i
21 radioactive material released.
22 CHAIRMAN ZECH: What was the power level at the time 23 of the accident?
24 MR. PANCIERA: It was 100 percent.
25 CHAIRMAN ZECH: Yes. Thank you.
l l
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l' 13 1 MR. PANCIERA: There was no indication that a water 2 hammer occurred.
3 I would like to show the next slide, please.
4 Would you rotate it 90 degrees? No, the other way.
5 Okay.
6 I put two sketches on. The left-hand sketch is the l 7 elbow where the fracture occurred, and it's showing the elbow _
8 in an intact condition. The line that is on the elbow shows 9 the actual fracture.
10 The right-hand slide shows the fracture, the elbow i
11 after the fracture.
12 COMMISSIONER ROBERTS: Is that albow a forging?
13 MR. PANCIERA: that was a wrought fitting.
l 14 COMMISSIONER ROBERTS: What is the diameter?
15 MR. PANCIERA: 18 inches.
16 COKNISSIONER ASSELSTINE: So the header, I take it, 17 went horizontally across the top?
18 MR. PANCIERA: The header went horizontally across i
19 the --
20 COMMISSIONER ASSELSTINE: Just came off of it?-
21 MR. PANCIERA: And the elbow came off of it, and I 22 have a photograph that shows that.
23 COMMISSIONER ASSELSTINE: Okay. Thank you.
24 MR. PANCIERA: The right-hand shows the -- you know, 25 the elbow after rupture. There's three pieces to it. The
n.
7
,- 14
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1 right-hand. piece was the section that was connected to the 2 24-inch header. The lower portion was connected to the 3 section of the feed pump, and the piece that's in the middle, 4 the standard piece, it's a 2 x 3 -- 2 foot x 3 foot piece that 5 actually was projected about 20 feet and landed on top of a 6 raceway.
7 The initial crack occurred in a dimple, a thin 8 section of piping, which was about 60 mills thick, and the 9 original thickness of the pipe was 500 mills. So that the --
10 there's a dimple of 60 mills or about 1/16th of an inch. This 11 was downstream of a weld and it appeared that the weld had 12 caused a certain amount of turbulence and had kind of removed i
13 some of the metal, forming that dimple.
14 The crack initiated there, and then stopped. And 15 that's what we think was the first hissing sound that we 16 heard. About four seconds later -- this was on the inside
~
17 radius of the pipe -- about four seconds later, in an area 18 about 60 degrees from that, there was another thin area, about 19 48 mills in thickness. That's the crack -- the second crack 20 initiated there. It went parallel to the weld, it was stopped I
21 at the weld, and went at a rapid velocity. That's what caused 22 the ejection of the top piece.
23 COMMISSIONER ASSELSTINE: So not much 24 leak-before-break?
25 MR. PANCIERA: There was not much leak-before-break,
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1 and there was -- you know, there was a general area of thinning 2 throughout the elbow, which I'll get into.
s 3 I'd like to show the photograph now. This is a shot 4 taken from the turbine building floor looking up. You'll see 5- on the left-hand side the connection to the 24-inch header, 6 and it shows the piece where the fracture occurred.
7 The other part of the pipe is on the right-hand part 8 of the photograph, and it shows the piece, and that's the 9 piece that connects to the suction of the pipe.
10 CHAIRMAN ZECH:' Can you point that out?
11 MR. PANCIERA: Yes, sir. Here we have the condensate 12 header, 24-inch condensate header. This is the section, and 13 this is horizontal. This is looking up at it. This is the 14 takeoff for the suction to the A feed pump. This is the 15 straight piece of pump. Now there was an elbow in here.
16 This is the other piece of pipe right here. You 17 can see it was displaced quite a distance here. This really 18 should be up, you know, the elbow is up here, and this piece 19 should really be up here. This piece was displaced about 20 seven feet, rotated, and that's what hit the discharge of the 21 other feed pump.
22 COMMISSIONER ASSELSTINE: Was flow coming out of 23 both ends?
24 MR. PANCIERA: I presume so, yes, sir.
25 COMMISSIONER ASSELSTINE: Okay.
s.
js 16 1 MR. PANCIERA: Because the feed pump had not --
2 basically all the condensate drained out of here.
3 COMMISSIONER ASSELSTINE: Right. Right. And the 4 . other one?
5 MR. PANCIERA: And the other one --
6 COMMISSIONER ASSELSTINE: Because of the check 7 valves.
8 MR. PANCIERA: -- the feed pumps were running for a 9 short time and there was a certain amount. But the amount 10 coming out of the free communication check valve was very 11 small compared, of course, to the total amount coming out from 12 the condensate hotwell.
13 COMMISSIONER ASSELSTINE: Okay.
14 MR. PANCIERA: As I mentioned, there was general 15 area thinning. The elbow ran from about 120 mills to about 16 390 mills, starting from 500 mills. The upstream pipe was the 17 pipe that connected to the 24-inch header and ran from about 18 150 mills to about 450 mills. And then the downstream pipe 19 ran from 295 mills to about 405 mills. So there was general l
l 20 corrosion throughout the entire part of the pipe with areas, 21 patches, that were very, very thin, like an eighth of an inch 22 or less. That's the whole situation as far as that goes.
23 COMMIS'SIONER ASSELSTINE: At some point down the 24 line -- you may be getting to it, but I'd be interested in 25 hearing what inspection requirements apply to each of these i
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,2? ' 17 1 three components,.the pipe and then also the check valves and 2 the main steam trip valves.
3 MR. PANCIERA: We're going to cover that.
. 4 MR. BOSNAK: Yes, we'll cover that.
-5 CHAIRMAN ZECH: Could you differentiate or conclude 6 whether it was corrosion or erosion?
7 MR. PANCIERA: We have classified it as 8 corrosion-erosion, which appears to be a mechanism where --
4 9 well, it appears to be a mechanism where you get a certain 10 amount of corrosion and you wash that corrosion away, and.I'm 11 not even really sure we fully understand the actual mechanism.
12 CHAIRMAN ZECH: That's why you are calling it both, 13 I guess.
14 MR. PANCIERA:
Yes, sir. But I_ think that this will 15 be addresssed further.
16 CHAIRMAN ZECH: All right.
17 MR. PANCIERA: But that's the kind of thing that we 18 found.
19 CHAIRMAN ZECH: All right.
20 MR. PANCIERA: And we also found areas where you saw 21 a lot of areas where there was not a lot of erosion --
l 22 CHAIRMAN ZECH: But you're sure there was some 23 corros' ion, and then you're sure there's some erosion? You're 24 saying it was both?
l 25 MR. PANCIERA: Yes, sir. We saw areas that there i
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7 18 1 was black oxide with solid film of black oxide, and then there 2 were.other areas where there was no black oxide, but a red 3 oxide, indicating maybe that black oxide had formed-and then 4 washed away.
5 The pressure, as I mentioned, was about 370 psi in 6 the system. When the trip occurred, we got about 150 degree 7 -- I mean 150 psi pressure spike, just normally because of the
- 8 trip. Basically we are dealing with about 500 psi. If you 9 calculated the burst pressure at 600 psi for this kind of 10 pipe, the pipe would rupture, given a 90' mill thickness. The 11 thickness was actually less than that, so we think -- we are 12 very, very certain that the reason the rupture occurred was 13 because of the thin area of the pipe, and that's what caused 14 it.
15 The rupture resulted in the injury to eight persons.
16 Two persons were treated and released because they had minor 17 injuries. Six were hospitalized; four subsequently died; and 18 then one was released. And then my understanding as of just a 19 little while ago, one still remains in the hospital.
20 On December 10th, the day after the Unit 2 event, 21 Virginia Power decided to shut down Unit 1 and inspect the 22 piping. Subsequently we found that similar thinning -- maybe 23 not as extensive or not as great, but similar thinning occurred 24 in the same sections of the Unit 1 piping.
25 CHAIRMAN ZECH: Did you measure that?
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-1 MR. PANCIERA: That was measured,.yes, sir, and 2 there was an extensive inspection done on Unit 1.
3 CHAIRMAN ZECH: What were those readings compared to 4 the ones you just gave us, do you know?
5 MR. PANCIERA: They were like 230 mills; that kind L
6 of thing; in that neighborhood. They weren't as much, but j 7 they were still quite a lot.
8 COMMISSIONER ROBERTS: -
When did Unit 1 get its OL 9 and when did Unit 2 get its OL?
10 MR. PANCIERA: I think in 1975. Can someone help me i
l 11 on that?
12 MR. STEWART: Surry 1 in '73, and Surry 2, '75, as 13 far as I remember.
c 14 COMMISSIONER ROBERTS: So Unit 2 is two years l
- 15 younger, but there was more thinning in Unit 2 than in Unit 1?
16 MR. PANCIERA: But from a point of view of critical l 17 hours, my understanding is both units came very, very close to 18 critical hours, and that's what we really looked at. I forget 19 the number, but it was like 70,000 critical hours. It was 20 very close.
21 CHAIRMAN ZECH: All right. Go ahead, please.
22 MR. PANCIERA: I'd like to go to the next slide, 23 please.
24 I'd like to now cover the augmented inspection team 25 activities. With regard to these activities, an unusual event v w-c_%. ,,...mm.,c-r, ._,__y --_v,y ._....y-,_, c----ry-----...em,_me., e., --w-----,r
.p 20 1 was declared by the plant at 2:27. The fracture occurred at 2 2:20. So about seven minutes later, they -- an unusual event 3 was declared.
4 At 2:40, an alert was declared. The purpose of 5 declaring the alert was primarily for pe'rsonnel 6 accountability. They were looking for people and so they 7 terminated the alert at 4:25, when they had assured themselves 8 of personnel accountability.
9 A regional team was formed at 3:30 p.m. that day, 10 that same day. The team was dispatched to the site and 11 arrived on the site at 9:30 p.m. The team consisted of two 12 resident inspectors, two plant systems engineers, a 13 metallurgist, a health physics specialist, and a public 14 affairs specialist. So we had fairly good coverage.
15 COMMISSIONER ROBERTS: Did this come out of the 16 region?
17 MR. PANCIERA: This came out of the region 18 initially. The plant -- the team met with the plant staff 19 after 9:30. The first thing we were interested in was the 20 operational status of the plant. We determined that the plant 21 was in a safe condition. We toured the damaged area, and we 22 did all that before we left that night.
23 The next morning the team was upgraded to an 24 augmented inspection team with the addition of a member from 25 the NRR who was knowledgeable in water hammer, because at that
_ ;* 21 1 time there was some concern that water hammer may'have been 2 the thing-that caused the rupture.
3 The team remained.onsite for the remainder of the j 4 week, and on February 17th, we issued a draft executive l 5 summary, and that was to get the word out quickly to the 6 people who had to know about the situation. We were in 7 communication on an hourly basis all throughout this with the 8 region, and the region in turn with Headquarters.
9 During the weeks of December 22nd, 29th and January 10 12th, AIT inspection activities continued. We kept going back l 11 there, because this was the kind of event that was not over 12 quickly, and there was a lot of follow-up work that had to be
, 13 done. So I did not conclude the AIT until I was satisfied that everything was -- we understood what was going on.
14 15 In addition, specialists in fire protection, i 16 security, chemistry, and metallurgy were dispatched to the 1
l 17 site during that period', other than the team members, because l 18 I requested that.
j 19 The NRC Headquarters team arrived on the site two l
l 20 days after the event and spent the afternoon touring the 21 site. This included experts from the national labs. AIT 22 activities were completed on January 14th, after we reviewed l
i 23 the Virginia Power evaluation, which was issued on January 24 12th, and we also completed additional supplemental l
l 25 inspections.
l l l
l l
[' 22 1 I issued -- the region issued a final AIT inspection 2 report on February 10th.
3 I'd like to go to the next slide, please.
4 This next slide shows the three areas I intend to 5 cover dealing with equipment system malfunctions. I'll skip
, 6 that.
7 The next slide, please.
8 -
I'll quickly go over this next one, because we 9 discussed it in some detail.
1 10 Do you want me to go up and --
11 CHAIRMAN ZECH: Yes, if you would, please. I think 12 that would help. Thank you, i
4
- 13 MR. PANCIERA
- This is the main steam trip valve 1
3 14 whose function is to isolate the steam generated in the event 15 of a steam line break. It's a reverse-acting swing check 16 valve. Basically this is in the closed position, this is in 17 the open position (indicating). The open position at an are 18 of 80 degrees, the disc is held in position by means of two 19 gas cylinders that are attached to instrument air. The 20 instrument air is normally at 100 psi.
21 Because the licenses had been working on a i 22 newly-installed air compressor, the air pressure was allowed l
l 23 to decrease to 78 psi. Normally, 78 psi would be an acceptable l
24 air pressure to hold the seat in its open position; however, 78 25 psi in combination with a problem of assembly of the valve
- - . . , . - . . , . . . - _ _ . - , _ , _ . _ - , . _ , . , _ . , . . . . _ _ , _ _ _ , - _ , , , , , , , , , _ , ,,,,,,__,__.....__,,,,,_.m-__..m. .._-._-_,.,__,_,.,m__,,
\*
- 23 1
~
caused the valve to-go shut. This is a seat cover and this is 2 a stop tube that sits here. It's supposed to stop the motion 3 of the disc at a certain point. This cover had been rotated 4 one bolt hole, so when it was rotated one bolt hole, this stop 5 tube projected further into the steam path because it wasn't
- 6 symmetrical.
7 So what happened was the rotation of this cover did 8 not permit the valve to go to the entire swing of 80 degrees l
l 9 and it only could go to 62 degrees. So the combination of the 10 fact that the disc was sitting further in the steam flow, plus 11 the reduced air pressure caused the valve to go shut. That 12 was the initiating event.
13 CHAIRMAN ZECH: Was that a maintenance problem or an i
14 installation problem?
15 MR. PANCIERA: It was an installation problem. We 16 determined that there were inadequacies.in the maintenance 17 procedure in a number of places and a citation has been 18 issued.
19 COMMISSIONER ASSELSTINE: Isn't there some fairly 20 obvious way to make sure that the cover is lined up right?
21 MR. PANCIERA: ,Yes, sir.
22 COMMISSIONER ASSELSTINE: Is there a mark on it or 9
23 something?
24 MR. PANCIERA: That would be the appropriate thing, 25 is to scribe a mark.
, , . . _ - - _ _ _ . _ . , . _.r---,_.~.,__._.w.,-._ , _ _ - - . , _ . - . - , - - , , - - . . , - - . , - . . - - - - - -
i, , p 24 1 COMMISSIONER ASSELSTINE: But there wasn't in this I 2 case?
3 MR. PANCIERA: In this case there was not. But I 4 think the plant -- one of the parts of the procedure now is to 5 scribe it so that you know when you're putting it back that 6 you're putting it back in the same orientation that you had it 7 previously. ~
8 CHAIRMAN ZECH: I hope that's the kind of information 9 that we're getting out to everybody else, all the other 10 plants. Are we?
11 MR. PANCIERA: The cover was removed because there f
12 was some maintenance work done on the valve during the previous
- , 13 outage. That's the reason. So it wasn't -- they actually did 14 work on the valve and they just reassembled it with the 15 orientation in the wrong position 16 CHAIRMAN ZECH: Let me just say I hope we are 17 getting this kind of information out to everyone else in a
( 18 kind of a lessons learned approach. Are we doing that?
l 19 MR. VOLLMER: Yes, sir, we are.
20 MR. PANCIERA: I'd like to go to the next slide ,
21 while I'm up here. i 22 COMMISSIONER ASSELSTINE: I agree with that, Lando.
23 I can't imagine anything more fundamental than making sura l 1
24 that you put the lid back on in the right spot.
1 25 MR. PANCIERA: That main steam trip valve was in a 1
s
, - . - , - - ,--,,,----,-wn--w-,---,,---w,,_, , , .-,,nn.
25
/
1 safety-related portion of the plant and came under our scrutiny 2 as far as adequate procedures. !
I COMMISSIONER ASSELSTINE:
3 So this is Q list 4 equipment. -
5 MR. VOLLMER: That's right.
6 (Slide.)
7 MR. PANCIERA: This is the feedpump discharge check 8 valve. It's just a large check valve having two hinge pins, 9 one on either side and holding this disc in place. You have a 10 seat that's placed in the body of the valve mechanically.
11 Mechanically it looks like this. Here's the body of the 12 valve, here is a dog or a clamp that sits against the body of 13 the valve that's holding the seat in position, and this is a l 14 bolt that goes into the body of the valve.
15 What happened w~as there was a lot of erosion right 16 at this point here (indicating). Very heavy erosion. So what 17 happened was this piece eroded away, allowed the clamp to 18 loosen and then allowed the seat to be displaced. So the seat 19 was displaced like this, and there was actually free 20 communication between the upstream side of the valve and the l
21 downstream side. You could actually take and put your hand in 3 22 there and go from one part of the valve to the other.
23 So this was found on three of the four feedpump 24 discharge check valves. The fourth one had been overhauled 25 sometime ago and it was in good condition. But basically, on l
) 26 O;
1 all the other three, another had the hinge pin missing and all f
2 of them had loose clamps.
3 CHAIRMAN ZECH: Were all these things checked in the ,
4 other unit when it was checked out?
5 MR. PANCIERA: Yes, they were. Yes, sir.
6 COMMISSIONER CARR: When they overhauled the fourth 7 one, did they find that erosion?
8 MR. PANCIERA: When they overhauled the fourth one I 9 believe they did not find the erosion, and that's one of the 10 ' reasons why they made the decision that they would not do any 11 additional inspection on these.
l j 12 COMMISSIONER ASSELSTINE: This is what, about a year 13 or so after San Onofre had the check valve problems. Why is 14 it that this occurred after an event a year before that 15 supposedly told us and all the industry that there are some 16 real questions about check valves and the maintenance and ,
! 17 degradation of those valves, and that everybody was supposed 18 to go check their check valves. How did this happen?
l l 19 MR. PANCIERA: I really don't know.
20 COMMISSIONER ASSELSTINE: Do you know what they did, j 21 other than check --
i 22- MR. TAYLOR: Perhaps I can help with that. Besides 23 all the notifications of the problems in the San Onofre event, 24 there was a check valve owners group formed. We have tried to L
25 work with the check valve owners group and there was an SOER
{ '
l
j 27 1 put out by INPO in October of this past-year, October 15th, to 2 all licensees. It's a rather extensive SOER covering check
- 3 valves in feed systems and other important systems in the 4- plant.'
5 That SOER is actively being worked in the industry; 6 we get feedback from INPO that they've got lots of questions.
t 7 INPO will be starting about April after they have an SOER out 8 -- this is a so-called yellow SOER, not the sort of red'one, 9 not a red alert, but it's the second category. The utilities, 10 as I said, are working on the SOER. It outlines testing and 11 inspection concepts and programs to put into place, and this f
- 12 all grew out of the San Onofre event.
[
13 COMMISSIONER ASSELSTINE: When was that?
Was that 14 November or December of '857
, 15 MR. TAYLOR: Yes., It was in th'at timeframe, I can't i i 16 recall the exact date. INPO will, commencing about the i
17 beginning of April, in its evaluation cycle include this SOER 18 for part of its check at the plants. So the process INPO i
19 would expect to find as they proceed through their evaluation 20 cycle in about 15 months is that people have these programs 21 where they've been lacking in place, on check valves generally. I
! 22 COMMISSIONER ASSELSTINE: Which will be about three l 23 years after San Onofre.
i 24 MR. TAYLOR: It will take a while, yes.
25 COMMISSIONER ASSELSTINE: What did we do after San
~m- m.,-- -
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_. 28 4
1 Onofre? Did we just -- was it just information notices?
'2 MR. TAYLOR: Yes. We turned to an owners group in .I 1
3 addition to the SOER --
4 COMMISSIONER ASSELSTINE: And relied on the industry 5 to do it.
6 MR. TAYLOR: And relied on the industry, yes. In
, 7 addition to the SOER, we learned some things at San Onofre i,
8 besides check valves' functionality and testing. We also
! 9 learned about design placement of the check valves. Do you 10 recall that, how close it was to the discharge?
11 COMMISSIONER ASSELSTINE: Right, right.
12 MR. TAYLOR: And so the owners group has been I
- 13 working on an application guide to issue, and has had various 14 drafts of that. They're working with EPRI. And that guide, l 15 which is intended to also increase the sensitivity to the '
16 potential of mislocation of check valves, is supposed to be 17 issued, be finished and published sometime this summer.
18 So it is a long process that has been going on. We r
19 are -- since this event, I became quite concerned about check 20 valve aspects even though that was not the cause of this 21 event. We've asked the owners group to speed up. I would 22 suspect we may do some further checking to see how well the 1
23 work is going on, and particularly at the older plants. I 24 think there is some age correlation to cycle failure. ;
25 COMMISSIONER ASSELSTINE: I realize that there are a
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t 4
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29 1 lot of complex aspects to the check valve problem, including 2 the design -- I remember at San onofre the valves themselves 3' might not necessarily have been bad but it's in that particular 4 application they just didn't fit very well.
5 But I guess with 20/20 hindsight I would have to say 6 that a common sense thing to have done for every one of these 1 7 utilities that had check valves would be to at least go out
[ 8 and take apart a fair number of them and see whether they were 9 substantially degraded or not. It may take a while to sort
! 10 through all of the other issues, but at least to find out 11 whether these things were about ready to. fall part or weren't 12 working properly would be a sort of common sense thing to do.
, 13 Am I wrong on that?
I 14 MR. TAYLOR: No. I believe our information was that 15 Virginia Power had previously disassembled a valve, one of 16 these valves, and repaired it due to an indication of a
! 17 problem in -- I'm not sure which unit this was in -- and 18 actually had scheduled the other three check valves for l
i 19 inspection at the next refueling outage for each of the 20 plants. So they'd had some plan to get into these valves.
21 This accident occurred before the valves were gotten into l 22 completed. I l 23 This is a relatively old Crane design. It's a l
24 little bit of an unusual check valve design. You come in from
.25 the top. It was designed for ease of maintenance so you could l
l
. ~ _____ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ .
-- _ . ~ , _ _ _. . _ . _ _ _ _ . _ . _ . _ _ . _ . .. _ _ _ _. _ _ . . _ , _ _
d
~
4
- 30 a
1 get'right into the seat and take it out because of seat wear.
2 With a clamped-in seat it's a little unusual. I think one of 3 the fixes was to seal weld this -- I hope I'm not getting i 4 ahead of the presenters, but --
- 5 MR. PANCIERA: One of the fixes, they intend to --
i 6 they're working with the valve manufacturer to develop a seat 7 that will be welded in place. They also, before startup, did 8 modify the pins so that they'were truly captured and wouldn't
- 9 come out.
10 COMMISSIONER CARR: But the reason the seat came out i
11 of this one was because of erosion of the body of the valve, 12 as I understood your description.
i l 13 MR. PANCIERA: Erosion of the clamp.
i l 14 COMMISSIONER CARR: It was only the clamp and not 15 the body?
l l 16 MR. PANCIERA: It was on the clamp, not the body.
I 17 In fact, the clamp was extensively corroded and eroded, but 18 the body appeared to be fine.
19 COMMISSIONER ROBERTS: is the clamp the same material ,
20 as the kody?
21 MR. PANCIERA: I think it is. There was a weld --
f 22 MR. TAYLOR: There's a lock wire, too, that was 23 gone, right, Vince? ~
l 24 MR. PANCIERA: Yes. But this piece here, this lip 25 was welded to this piece here (indicating]. The weld that
- 9
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,_nn-n,.-,---,-~-.--,.n,._n_, _ , - . , ,.__n.
p,,-..,w , . , . - - --
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,- 31 e
1 bolted this strip was in excellent shape, beautiful shape.
2 CHAIRMAN ZECH: Can you grab the microphone, please?
3 MR. PANCIERA: The lip that holds the seat in place
, 4 against the body, this piece here, was welded to this piece.
1 1
5 The weld was in excellent shape, in very, very good shape.
6 The base material was the thing that was very badly eroded.
7 It looked like a moon surface.
I 8 COMMISSIONER ASSELSTINE: But when they looked at 9 the one valve, I take it they really didn't find a lot of 10 these problems? The valve was in great shape?
11 MR. PANCIERA: Yes, sir, that's my understanding, is 12 the valve was in good shape.
13 COMMISSIONER ASSELSTINE: So they looked at one, the 14 one turned out to be good so they decided well, we don't have 15 to worry about looking at the others until the next refueling 16 outaga, i
17 MR. PANCIERA: That's my understanding.
18 COMMISSIONER ASSELSTINE: How many of these valves I
19 do they have? How many check valves do they have?
20 MR..PANCIERA: They have four of them. -
i l
21 COMMISSIONER ASSELSTINE: Just four check valves in
)
22 the whole plant?
4 23 MR. PANCIERA: Well, four check valves in this i
24 application, one off the discharge of each of the main 25 feedpumps, and there are four feedpumps in the two units. Two i
32 l units, two feedpumps per unit.
2 COMMISSIONER ASSELSTINE: So eight. check valves 3 total in --
4 MR. PANCIERA: No, four check valves. -
5 COMMISSIONER ASSELSTINE: Four check valves total in 6 the whole plant.
7 MR. VOLLMER: No, we're talking about a plant 8 population of a couple hundred probably.
9 COMMISSIONER ASSELSTINE: How many check valves did 10 they look at out of the total population of a couple hundred?
i 11 MR. PANCIERA: I don't know.
t 12 MR. VOLLMER: There are two other check valves of 13 this design in the recire, feedpump recirc line. I gather I
14 that would make a total in each plant of at least three of 15 this particular design. They immediately pursued the desi'gn
! 16 because part of the problem here is this clamp assembly issue 17 as against other wear of a hinge pin or so forth -- part of 18 what failed in those three was the design had a feature 19 contributing to that.
l 20 I can't answer the extent -- we have asked Virginia l
21 Power and I think the Region is getting it, their plan for L 22 overall check valve, and the company is going to provide that 23 very shortly to the Region and to Headquarters. We're 24 interested in their overall plan of going through check 25 valves. But they did immediately on this design, you know, I
33 1 .get into it. We asked, too, where are these valves used.
2 COMMISSIONER ASSELSTINE: If you could find out at 3 some point I'd be interested in knowing, after San Onofre, out 4 of the total population of a couple hundred check valves in 5 the plant, how many they looked at.
6 MR. VOLLMER: We'll do that. I wanted to point out l 7 I think it's probably obvious from what was said before these 8 particular events that we're talking about, San Onofra'and 4 9 this and some others, that there have been and still are no 10 specific regulatory or code requirements to inspect a number 11 of these things. And so we're working from the ground up to 12 establish the need to and the type of inspections and the 13 periodicity and all that sort of stuff.
14 A number of these were looked at just when the 15 utility felt it was prudent to do so from an economic and
- 16 system point of view.
t 17 COMMISSIONER ASSELSTINE: Yeah, I want to get to 18 that at some point, too, about the inspection program for 19 these things.
20 MR. VOLLMER: Okay.
21 COMMISSIONER BERNTHAL: I think it's worth making a i
22 comment. I agree with you, Jim, in this case it's check 23 valves and perhaps fire protection systems as well, which I 24 want to ask a question about later. But I want to make very 25 clear here for the press and others that that was not the
4
' 34
,/
1 cause of this accident; that that erosion sooner or later 2 would have failed the pipe.
3 MR. PANCIERA: Yes,
- j. 4 COMMISSIONER BERNTHAL: But it is.true, it seems 5 like every time we have a major incident and really start 6 digging into a plant, then we discover these things that are 7 cause for concern.
8 COMMISSIONER ASSELSTINE: Well, in this particular 9 case, too, I think this is a cause for concern that I thought 10 we had all learned about more than a year ago, and this is a 11 good test of how effective I think these industry follow-up 12 program really are.
13 COMMISSIONER BERNTHAL: I agree. I just wanted to l
14 make clear what I thought the cause was.
15 COMMISSIONER ASSELSTINE: Yes. I think the pipe :
16 rupture question goes back I think to the point that.Lando 17 made in his opening comments. That and a lot of these other 18 things are the balance of plant, and I think the big question 19 is how much have we done in the balance of plant area and not 20 done, and what should this experience be telling us about the 1
21 vulnerability of the balance of plants, and particularly the 22 balance of plants where the functions seem to be very important 23 to safety. If not to the public, certainly to the workers in 24 the plant.
25 CHAIRMAN ZECH: I think it's probably worth pointing l
l-l - - - - - - - - - - - -
s ,,
v 35 1 out, thought, that a : cording to Mr.; Taylor this situation was 4
2: being looked at but it'ri 'still being looked at, and perhaps 3 not.only should we look at the whole issue but traybe ,the 4 timeliness of how long it takes to complete a prograd of this ti 1
5 importance should be looked at'also. -
1
'6 MR. TAYLOR: Yer, . Obviously, the check to do all
- 7 the check valve maintenance and inspection is an extensive '
8 task in any plant, and they schedule to outage as/a pick-up. , ;
9 We have asked the owners group to keep the feedback heavy on ,
10 looking at what we call the vulnerable. Not every check valve ^
-11 that fails is going to cause the same typo conssquences, but 12 look where you're most vulnerable co affect. /
13 CHAIRMAN ZECH: But I think wo'should ensure that 14 there'ssomeperhapsmoreformalprograNofschedulingthese 15 during outages and getting on them right away rather"than 16 having them extend over a period of years, because it looks , ,
17 like it, certainly in this case, was:.a vir; serious accident.'
i 18 And we've had check valve problemn before, as we've mentioned 19 earlier here today. So perhaps thic'dught to be higher on our 20 priority list than itts been and get more attention.. I think '
21 it's something we should look into very carefun y.
22 MR. TAYIDR: Yes, sir.
23 CHAIRMAN ZECH: Proceed, please.
24 (Slide.] ,
i 25 MR. PANCIERA: This.next slide shows the concerns we f
. , . . . . , . . . _ - ..-,..._ , - - ... -, _ .., .._: .~ - .. _ .- --.-.
, 3"
/^ 36 1- , had about the fire protection system. The rupture caused the
' actuation of significant portions of the fire extinguishing
~
,2
~
g.
3' systems. .There were 62 heads in the turbine building,
, (( 4 sprinkler systems, that actuated and this was due to the heat
>m ~
5 of the break.
, 6 COMMISSIONER BERNTHAL: Oh,, it was the heat and not
..s 7 'the -- I see, not because the electronic system somehow --
8 MR. PANCIERA: No, it was the heat of the break. In 9 fact, it cooled down that area. It may have even saved lives.
l db There's a carbon dioxide system that provides f
', 11 extinguishing capability for the cable spreading room.
/ The L2 cable spreading room is above the control room in this design.
v.v 23 The switchgear room is below the control room, so that you have i
}4 upper elevations in the cable spreading room, then the control 15 room, then the switchgear room.
4 16 The cable spreading room has a carbon dioxide i
i 17 system. The cwitchgear room which is below the control room
- 18 has a halon system. Both of these systems actuated. The 19 carbon dioxide system actuated primarily we think because of 20 'the actuation of the uprinkler heads. The water came down, 22 hit the control panel. There were openings in the control
! 22 panel and that shorted a time limit switch which then dumped
,23 the CO2. ,
- 24 At the same time, there was a control panel that l r 25 controlled the halon that was down in the lower level. That I.
y )
4
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Y 37
"* .1 cf gs 4 ).
.1 was?also aqtuated because'of intrusion of water into the 2
, , .s controlipanel.. .That probably.resulted from the sprinkler
( <
(
3 heads as well as'maybe some of the water coming down because t' %;
~
b4 of the break. So it was a combination of both.
5 bOMMISSIONER ASSELSTINE: I thought that the 6 sprinkler systems, when'you were designing a sprinkler system l 7 it would be fairly fundamental to look at where the water 8 would go to make sure that the water doesn't get in those 9 cabinets and short things out. I've been to plants where 10 you've gotilittle lids built over the - . Is this a problem <
11 in that t a company just didn't design its f. ire protection 12 system? '
3,*
13 HR. PANCIERA: I think that if the holes had been 14 plugged properly,tif there were no holes in the' cabinets --
15 there were actual conduit holes in the cabinet -- that probably a
16 this wouldn't have occurred. .
! 173 COMMISSIONER BERNTHAL: Better make sure it isn't an 18 NRC requirement. I have to tell you a story of the 19 requirements that DOE imposed on its laboratories when they 20- were undergoing construction. When I was at Michigan State we '
e) 21 were building a major new facility, and in this case DOE's 22 building codes absolutely required that we have a sprinkler 23 system over the computers in the compute,r room.' Well finally, 24 the lab director, I guess it can be told now, said all right, 25 we'll put the pipes in the sprinkler system but there isn't
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b y -- ~~ ,vm. ,w, m,- .,r - .- w w rw ww -v--* w~- rr-- - - - **-
38 4
1 any water going-in them.
2 So sometimes~--
3 COMMISSIONER ASSELSTINE: Well, we certainly have 4 required fire protection systems but I think the assumption 5 was that they be designed in a way that didn't cause --
6 MR. VOLLMER: To answer the question, yes, our 7 design and our Standard Review Plan requirements are that the 8 licensee is sure that there's enough drainage and insures that 9 things will be protected against impingement. But as we've i
10 seen here.and in other places, the system interaction problems 11 for fire protection may be significant.
12 COMMISSIONER ASSELSTINE: Have we done a fire 13 protection inspection of this plant?
14 MR. PANCIERA: I believe we have.
15 SPEAKER: No, it's coming up in April.
16 COMMISSIONER BERNTHAL: That is cause for great 17 concern, though, it seems to me, that not only -- we've had 18 two instances now recently, one at Palo Verde as I understand 19 it, where they had the diesel generator ~ fire and the fire 20 protection system, sprinkler system, did not activate. And 21 here we had a case where it wasn't supposed to activate and it L 22 did, for two different reasons. In fact, I guess the steam l
23 release you would expect to act,1vate the sprinkler system 24 because of the heat.
25 MR. VOLLMER: Or the steam -- depending on the type
. _ _ _ . = ._ . . _ . . _ -
39
~1 of detector, the steam looks like smoke.
2 COMMISSIONER BERNTHAL: There are lots and lots of 3 scenarios that you can imagine for water intruding. We.saw
'4 two, I guess, in this case . And beyond that, CO2 I gather 5 intruded into the control room as well, and/or the halon.
6 COMMISSIONER ASSELSTINE: Yeah, are you going to 7 talk about that, why the door was propped open?
8 MR..PANCIERA: Yes. At one point the decision was 9 made to try to. vent the cable spreading rooms and get rid of 10 the CO2. The cable spreading rooms were vented. They were 11 vented in part to the mechanical equipment room.
12 At the same time, the main control room complex 13 doors were open because of a problem with the card reader.
14 The card reader actually froze and caused the card readers to 15 malfunction, so the plant security made it to get people in ,
16 quickly to do their job, put station guards at all points and 17 did a very good job. They had two shifts there so they were 18 able to really do a real good job, and they opened up the 19: doors. So now you had the doors being opened up to the cable l 20 spreading room to get rid of the CO2, the CO2 then coming down l
21 to the lower elevation and getting into the control room.
22 There was also a negative pressure differential in 23 the control room at the time. ,
24 COMMISSIONER ASSELSTINE: So it sucked it in.
25 MR. PANCIERA: So it sucked it in. There was also a
- - - , . --i ,.y, - --.e. , , - . - - . , . , . _ .--me%w-,am-,,,,---,-_,,,.-------w-w- , - - - w
40 1 temporary mod to the ventilation where the control room was 2 actually taking suction on the mechanical equipment valve.
3 The control room ventilation was taking suction. So the 4 combination of these did cause CO2 entry into the control 5 room. This caused a certain amount of crew discomfort. There 6 was a certain amount of dizziness, a little bit of nausea and 7 shortness of breath.
8 The control room crew realized this and immediately 9 pressurized the control room. That had a tendency to help 10 greatly.
i 11 COMMISSIONER ASSELSTINE: Why did the card reader 12 freeze?
13 MR. PANCIERA: The card reader froze because it was 14 in the vicinity of the fire protection extinguishing system i
l 15 and it just -- the CO2 made it real cold.
16 The halon actuated and since this was below the 17 control, there was about a 7 to 10 percent concentration of 18 halon. There might have been some intrusion into the control 19 room from below, but we didn't feel it was really a problem 20 because this concentration of halon, plus the fact that it's 21 heavier, you aren't going to get much of a concentration in 22 the control room.
23 So that's what happened as far as the fire 24 protection.
l 25 COMMISSIONER ASSELSTINE: Have you looked at all of I
--m -
r, - -+ - -e--+
41 1 the situations including like the temporary mod on the control 2 room ventilation system to see whether all of those things 3 were acceptable?
4 MR. PANCIERA: Yes, sir.
5 COMMISSIONER ASSELSTINE: They were all done 6 properly?
7 MR. PANCIERA: Yes, we felt they were done properly.
8 In fact, I even had -- this is one area where I wanted a fire 9 protection engineer to go and really look at it. We spent the 10 whole week there.
11 CHAIRMAN ZECH: Let's proceed, please.
1 12 COMMISSIONER BERNTHAL: Do you have good systems for 13 testing these fire control systems? You know, really what you i
14 get back to, whether it's check valves or fire control systems 15 -- I guess in this case it may be partly a design problem --
16 but usually it's a maintenance issue. And one wonders again 17 how good are we or they at testing fire control systems to i
18 make sure they're functional. Do we do that enough?
19 MR. VOLLMER: Well, as I see these issues, the root, 20 if you will, would be a design issue.
21 COMMISSIONER BERNTHAL: I agree in this case.
22 MR. VOLLMER: More than the testing issue.
23 COMMISSIONER BERNTHAL: In the case of Palo Verde it 24 was testing apparently.
t L
25 MR. VOLlMER: Yes. Most of the fire protection
42 1 stuff,is fairly commercial grade, off-the-shelf items, fusable 2 links and'all these kinds of things. So they're UL-tested and 3 the like.
4 COMMISSIONER ASSELSTINE: Have you looked at how the 5 company went about designing its fire protection systems, or 6 is that something that will come up in the April inspection?
7 I guess what I'm particularly interested in is did they hire 8 fire protection engineers to do the work for_them, people that l 9 would understand you've got to track where the water goes and 1
10 plug up all the holes to make sure that the water doesn't get 11 into these systems; they can disable card reader systems, 12 those kinds of things.
13 MR. VOLLMER: Well, I can't answer what they did, 14 but I think the staff guidance is clear in this area. Now 15 we'll find out in April, but certainly from a review point of 16 view they did implement it to the staff's satisfaction but our 17 review is not 100 percent, as you know.
18 CHAIRMAN ZECH: It looks like we're about one-third 19 of the way through so we've got to move along.
20 (Slide.]
21 MR. PANCIERA: This is a very short one. The last 22 topic I'd like to discuss is the efforts to implement station 23 ,
recovery. I'll just briefly touch on this because I think Bob 24 will cover some of these aspects.
25 Shortly after the event, the Licensee implemented a I
, .r.,-.--.m__.--.m,, , , , - _ . _ - - - , , .w.,....-_.~
I l
. l 43 1 multi-plant program which included investigation, evaluation 2 and inspections. They did metallurgical examinations, stress 3 analysis, fracture analysis, and then an extensive program of 4 ultrasonic testing of piping and fittings.
5 Priority was given to Unit 1 because it was 6 recognized that Unit 1 had the best chance for an early l
7 restart. Ultrasonic testing was based on the effects of 8 erosion-corrosion on the following parameters; material, l
9 namely carbon steel, fluid velocity, temperature and water 10 purity. Systems were selected which handled water or steam I 11 where carbon steel had temperatures greater than 195 degrees l 12 F and contained deoxygenated fluids.
13 The Licensee also included systems outside these 14 parameters; namely, safety-related systems, aux feed, charging 15 system and condensate.
16 Within each system a rating scheme was devised based 17 on temperature, velocity and geometry, to pinpoint the areas 18 where it would be expected you would get the highest rate of 19 corrosion-erosion.
20 Conservative inspection criteria were developed 21 based on maximum calculated wear rates. They took the nominal 22 pipe thickness, added on the maximum thickness for corrosion 23 and then used that as the basis and assumed all piping would
! 24 be at that initial thickness.
25 As a result of this inspection program, there were
44 1- over 1000 components inspected.on both units. There.were 138 2 that were designed or designated for immediate replacement 3 before restart. There's also a number of components that are 4 scheduled for replacement in the next outage and there's an 5 extensive UT inspection program tha^,'s ongoing that will 6 continually update the status of these. I think they did ,
7 quite a thoro'gh u job in that area.
8 On Unit 2 the inspections have been ongoing. Unit 2 9 will not start up until sometime in March. They did find just 10 within the last couple of days an area downstream of the 11 auxiliary.feedwater piping -- this is in the safety-related 12 portion -- where there appears to be some thinning and the 13 Licensee is evaluating this.
14 The same area on Unit 1 was inspected prior to 15 restart and this thinning was not found to be there. The 16 thinning may be a result of improper or bad fitup on the pipe 17 because it's at a point where there's a reducer, and it may be 18 a fitter problem but we're not sure. But we know that Unit 1, 19 the unit that started up on the 23rd, did not have this 20 problem.
21 This basically concludes my part of the presentation.
22 CHAIRMAN ZECH: Thank you very much. Proceed.
23 [ Slide.]
24 MR. BOSNAK: This first slide is a quick summary of 25 staff actions which were initiated within the first few weeks
.- . _ --. - - = . - -
45
~
1 of the event. I just want to focus on just a few of them.
2 We initiated an independent failure analysis at 3 Brookhaven Labs. We have just gotten the report back from 4 them and the results are down at the bottom. Definitely, this
- 5 was a ductile tearing failure which resulted from the over 6 stressed condition. Secondly, the material, chemical and i
l 7 mechanical properties were all within the specification 8 limits.
9 I am going to cover in several slides the technical 4
- 10 experts' meeting that we had on the 15th of. January. We did 11 issue I&E Notice 86-106 and just recently Supplement One to 12 it.
13 Next slide, please.
(Slide.]
14
- 15 MR. BOSNAK: The technical meeting that we had here 16 on H Street on January 15th was really to discuss what I call 17 the metallurgical aspects of the failure,'the generic 18 implications. It's really basically the wall thinning. We 19 had disciplines representing piping designs, fluid mechanics, 20 metallurgy, NDE, water chemistry and corrosion. There were
- 21 six individuals on the group.
22 Earlier we discussed what is erosion / corrosion. I 23 think this is a good definition here of erosion / corrosion. It ,
l 24 is really flow assisted corrosion. The erosion process is the 25 removal, if you will^, of the rust that occurs, the magnetite,
46 1L and it is not erosion in.the typical sense, if you think of 2 something being eroded. There is a phenomenon called erosion 3 where you have for instances things like suspended solid silk 4 and those kinds of things in the flow stream.
5 This is erosion / corrosion. It is really basically j 6 flow assisted corrosion, where you do haveythe metal oxide 7' removed. There are certain variables that abet the process.
8 These are the things that were identified in the meeting.
l 9 We did also conclude that the actual failure was not 10 due to a classical water hammer event, it was just a system 11 pressure transient.
l 12 COMMISSIONER ASSELSTINE: Are you going to talk 13 -about the other role that you think water chemistry may have 14 played in this problem?
l i
15 MR. BOSNAK: Yes; we are.
16 COMMISSIONER ASSELSTINE: Good. I think anybody who 17 has seen the steam generator out in Washington, Surry, knows 18 that certainly in the early years, this plant had just plain 19 lousy water chemistry.
20 MR. BOSNAK: That was one of the points -- in fact, 21 one of the people that we had on our panel was involved in the 22 earlier Surry work.
t 23 Now, there were five observations and four 24 recommendations that came out of this meeting. First of all, 25 let me touch on the pioing design. Codes and standards have
_...,_~_._ , _ _ _ _ _ _ _ _ . , _ _ , _ . . - . _ , _ _ _ _ _ _ . _ _ _ _ _ _ _ .
47 1- traditionally avoided anything to do with the environment'and 2 the environmental effects except things that contribute to 3 mechanical loads, things like wind load, earthquake load.
- 4 They'had not gotten into these kinds of things.
5 some of the design equations speak to an allowance 6 for erosion or corrosion but it is left to the designer. Most 7 people, either they add something -- it was common practica
. 8 over the years to add something like 1/16th of an inch, but 9 normally this may or may not be done.
10 There is little guidance in this area. Some AE's as
'l 11 was brought out at the meeting do limit bulk flow velocity of
- 12 the fluid, a number that was bandied about was ten feet per i
13 second but this is not certainly an upper limit or was not l
14 meant to be considered as an upper limit.
! 15 They also, some AE's, give some guidance with 16 respect to configurations, geometrical configurations. They 1
l 17 avoid things like splitting Tee's if it is at all possible.
l 18 They use 45 degree laterals. In other words, things that
}
19 reduce the turbulence. ;
20 There is no standard. There is no overall guidance 21 that the industry uses.
I 22 Second was the effect on revision to GDC-4 and leak i
23 before break. First of all, in the guidance that the staff l 24 intends to put out on leak before break, there are going to be 25 many things that leak before break evaluation is not
48
~
1 permitted. In other words, if you have a situation in which i 2 you have prevalence for water hammer, creep, undefined fatigue, 3 erosion and erosion / corrosion, these are not permittad to use
! 4 the leak before break proposal.
5 Where we have used it so far, as you are well aware, 6 in the limited scope rule that applied to PWR main loops, in l l 7 those situations, we don't have these kinds of conditions 8 occurring. We are as a result of this Surry event, going to
, 9 take another look at the whole proposal to be sure that we 10 have things properly covered.
]
t 11 One thing that has been suggested would be perhaps a l 12 check of wall thickness before somebody goes into this leak I 13 before break alternate proposal.
14 COMMISSIONER ASSELSTINE: Why do these conditions 15 not exist in the primary loop?
. 16 MR. BOSNAK: In the primary loop, first of all, the 1
17 material is such that it is either fluidics clad or astigmatic 18 material. We are going to get into the question of material.
i 19 COMMISSIONER ASSELSTINE: Okay. The design concerns 20 you mentioned on the first bullet, do those apply throughout 21 the plant or is that only on the secondary side?
22 MR. BOSNAK: No. Those are typically applied across j 23 the plant in all systems.
i 24 The third and fourth observations were to pinpoint 25 the variables that affect the rate of erosion / corrosion R
,,---n,,,v-.- .-,-,-e--,,.-s-~,---w--.-r - _ n -,w -or e--w-w-&~w~'---v
49 1 damage, and there are a number of those. First of all, we 2 mentioned carbon steel. Carbon steel is a material that is 3 particularly prone to this kind of damage. Temperature plays I
4 a role. We have some slides coming up on that. pH and the 1 5 oxygen content of the' fluid.
6 It was very difficult as far as the panel was 7 concerned to decide which of the variables were the most 8 important because there is a complex interrelationship between 9 these things. They couldn't identify which was controlling 10 but they did cite the three most important variables; fluid 11 velocity turbulence, the water chemistry and pH and the 12 material composition, particularly the amounts -- you may call 13 these trace elements because they are not a normal alloying 14 element in plain carbon steel, but particularly chrome was 15 important.
16 [ Slide.)
l 17 MR. BOSNAK:
If we dwell on this area for a minute, 18 and this was not an unanimous decision, but we tried to rank 19 the variables at Surry. We noticed that all the variables 20 were perhaps in their most unfavorable range or condition.
21 First of all and perhaps at the top of the list was this elbow 22 splitting Tee configuration that you have seen pictures of.
23 COMMISSIONER ASSELSTINE: So these are in priority?
24 MR. BOSNAK: Yes, this would not be an unanimous 25 decision but yes. The pH levels of the system were somewhere
{'
50 1 between 8.8 and 9.2. From the water chemistry point of view, 2 if.you increased the pH and you get somewhere in the range of 3 9.2 to 9.5, the damage rate, and we have a curve that covers 4 some of that, drops off markedly.
L 5 The next thing was water chemistry during the 6 operating years, as you pointed out, that at least prior to l 7 the condensate polishing system, there were all kinds of 8 intrusions of things like chlorides, sulfates and other 4
9 chemicals that got into the system and just what role this a
lo might have played, no one was able to really pinpoint the 11 effect that this had on the system. obviously, it was perhaps 12 not the best.
13 Material composition, the particular elbow had a 14 very low trace amount of chromium. In this particular material l 15 specification, there are no requirements for chromium. It was i 16 down in the range of .02. You could have had, depending on the j 17 supplier and the melt of steel, the amount of scrap that was 18 used, you could have had higher amounts and you could have had i 19 another elbow say in the same plant that had higher amounts of 20 chrome and would have been more resistant. I just wanted to i
21 give you a feel for the fact that even though this is plain 22 carbon steel, you can get some variations in the amount of 23 trace elements.
24 The system temperature was in its most diverse l
25 range, actually at Surry, the temperature and pressure -- the I
k t
m., _ , . . . . _ .
51 1 pressure was 367, the temperature was about 380, that is at 2 the upper limit of where it drops off hs far as the effect of 3 temperature is concerned.
i 4 You have heard that the bulk fluid velocity was 5 about 17 feet per second in this 18 inch branch, which was 6 higher but not necessarily restrictive because at the meeting l
7 we talked about some systems that had much higher fluid 8 velocities.
9 The fact that the rest of the condensate feed water 10 system, the elbows were not really affected and it indicates l 11 that this was not a controlling variable.
12 The oxygen content in the system was quite low, 13 approximately in this range of one part per billion.
14 These are the materials that were involved. They 15 are all plain carbon steels. Again, the corrosion resistance 16 is a function of what you get in the particular heater material 17 and the scrap that went into that process.
18 The curves I am going to show you here come from 19 German research work done by Heitman & Kastner back in about 20 1982.
21 [ Slide.]
22 MR. BOSNAK: The first slide that we have on the 23 effect of pH and oxygen, if you look at the little box, the 24 legend, that gives you, if you look at the top bar, that is pH 25 of seven, neutral pH, and a rather high oxygen content. The l
i 52-1 middle is a pH that is higher and low oxygen and finally the 2 bottom is again a neutral pH with low-oxygen.
3 If you focus on the second. horizontal on the carbon f 4 steel, if you will notice that again, if you increase the pH ,
5 and keep the oxygen constant or increase the oxygen, you 6 markedly reduce the amount of wear. It's quite critical to I
! 7 these kinds of things.
l 8 Looking down, the fourth row from the bottom, it ,
1 9 shows you the effect of adding one percent chrome to the half 10 Molley carbon steel that is shown at the top. Again, the one i 11 percent chrome markedly reduces this.
12 COMMISSIONER BERNTHAL: I thought in general, wasn't 13 one of the objectives to keep the oxygen content rather low?
14 MR. BOSNAK: Yes, and that was because of the steam ,
j 15 generators.
i 16 COMMISSIONER BERNTHAL: Exactly. You have two ,
17 conflicting efforts here.
L i
18 MR. BOSNAK: You have two conflicting things. One l
19 of the recommendations, in fact the first recommendation of i
( 20 the panel was don't do things arbitrarily, in other words, .
t I 21 don't do something that you think might serve to benefit this i 22 area in the system without really knowing what you are going 23 to do to the steam generator. Yes, you do have two conflicting 24 things here.
I 25 COMMISSIONER BERNTHAL: Before you leave this, the .
t
53 1 point is that stainless steel isn't subject to this sort of 2 problem.
3 MR. BOSNAK: That's correct. The 18 chrome stainless
-4' is not.
5 COMMISSIONER BERNTHAL: If you look for regions, 6 even in the balance of plant, where you are likely to have 7 those kind of highly turbulent flow and erosive situations, 8 not corrosive, might it not be advisable to go with stainless 9 steel in those kinds of joints and in those circumstances?
10 MR. BOSNAK: I think particularly Virginia Power is 11 considering not necessarily stainless steel but a low alloy 12 steel in some of these areas.
13 COMMISSIONER BERNTHAL: Some other steel.
14 MR. BOSNAK: One of the ways to mitigate this 15 obviously besides a periodic measurement is to put in material 16 that is resistant.
I 17 COMMISSIONER ASSELSTINE: Is the use of the kind of i
18 material at Surry in these areas typical?
19 MR. BOSNAK: Typical. Yes; it is.
20 COMMISSIONER ASSELSTINE: For this country as well 21 as for other countries?
l 22 MR. BOSNAK: That's correct. In this area of the 1
i 23 plant, you normally use carbon steel.
24 (Slide.)
25 MR. BOSNAK That again illustrates the effect of
.54 1 the solubility of the corrosive product. That is the 2 magnetite. It becomes very soluble at a peak somewhere 3 around 300 degrees Fahrenheit and then it drops off, the 4 solubility drops off markedly. Again here, at Surry, we were 5 comewhere about 380, generally up to the peak.
6 (Slide.]
7 MR. BOSNAK: Lastly, the curves. Just illustrates 8 the effect of fluid velocity. It shows that it is an 9 exponential. By the way, these are all semi-log plots. It 10 does show the effect again even with increased fluid velocity 11 on material.
12 COMMISSIONER BERNTRAL: Can you explain to me in one 13 sentence why the solubility drops at higher temperatures?
14 MR. BOSNAK: I don't think I can do it in one 15 sentence. Besides it being very soluble, supposedly there 16 could be another oxide that takes over and just causes this to j 17 become resistant as the temperature goes up. Also, there are l 18 certain -- because there is air intrusion into the system, you 19 have carbon dioxide. You have ce a result carbonic acid.
l 20 This at these temperature ranges also breaks down. Again, 21 this is not a thing that I guess everybody concurs in but we 22 discussed this briefly with the water chemistry person we had 23 at our meeting and he felt these secondary acids that were set 24 up as a result of the carbon dioxide intrusion plays a role at 25 this range in temperature. That plus the fact that the
55 1 magnetite is just more resistant plus you have other oxides 2 that are forming as the temperature goes up. That resists the 3 effect on the ferrous material below it.
4 COMMISSIONER BERNTHAL:. Sounds'like you don't 5 understand it very well.
6 MR. BOSNAK: Let's go over to the slide on 7 Observation No. 5.
8 (Slide.)
9 I think this is probably one of the more important 10 areas. We wanted to be sure that the industry was aware of 11 the fact that these things are there. I think everyone is 12 aware that we do have particularly erosion-corrosion and some 13 erosion in lines that have had failures, and that is the wet 14 steam lines, again in this balance of plant. Steam extraction 15 lines, crossover lines all have had failures. That is the 16 two-phased system that you see here.
17 So there have been I&E notices, an AEOD memo, EPRI 18 and INPO documents, and the utilities have had voluntary 19 programs because they have been aware of failures.
20 COMMISSIONER ASSELSTINE: Was there any reason to 21 believe at the time that the problems would be limited to the 22 two-phase systems or these single-phase systems with suspended 23 solids?
24 MR. BOSNAK: We know of -- and, of course, these 25 were in completely different situations. We knew of inlets to L
56 1 heat exchangers. We knew of things like J-tubes, bypass lines 2 around the feed pumps, minimum flow lines where you have a lot 3 of turbulence. There just weren't any -- in fact, until just 4 yesterday, when I heard of another failure. We checked. At 5 the meeting -- we discussed this with insurance company 6 people, with the national board. No one was aware, but we i
7 speculated that perhaps there were some of these failures that 8 had no effect other than -- there were no personal injuries,
- 9 and all the utility or the particular industry where the thing 10 occurred, they repaired the line and it was not reported.
J i
11 We just heard yesterday and the EPRI has put out a 12 white paper of another failure in a fossil plant in November i 13 of 1982. That is the first time we have heard of another 14 failure. So we can still say that this particular phenomenon 15 in these large lines is quite rare.
16 COMMISSIONER ROBERTS: But it is not unique just to i
17 the nuclear plant.
18 MR. BOSNAK: No, it is not unique just to the 19 nuclear plant.
l l 20 COMMISSIONER ROBERTS: I would think EPRI would be 21 the lead on this. Anybody that would generate steam, 22 regardless of the method, would have to be terribly concerned 1
i 23 about this.
24 MR. BOSNAK They are, and as I say, they have just 25 put out a white paper on, again, the same kinds of things, 1
' ,__---.---- , ,~ -., .-_- ,
57 1 pinpointing the variables as we have done, suggesting !
2 measurements, methods for measurement taking, and pointing out i 3 .that this does affect not only nuclear. utilities but certainly ~
4' all utilities. And again, this failure in 1982 was in a fossil 5 plant. The plant was not identified as to which one it was.
6 COMMISSIONER ROBERTS: Was it similar to this i
7 erosion-corrosion?
8 MR. BOSNAK: It was identified in a report as being
{
I 9 erosion-corrosion. It was in a 10-inch line. It was in the 10 feedwater suction line. In this particular plant there is a 11 little higher pressure, but the temperature was about the I
12 same. It was on the discharge side of the condensate booster j 13 pump, on the suction side of the feedwater pump.
- 14 COMMISSIONER ASSELSTINE
- And when did that occur?
15 MR. BOSNAK: November 1982.
{ 16 MR. VOLLMER: I think what has happened is there l
17 probably have been a lot failures, perhaps not as dramatic as 19 this one, in the fossil side, and things have been replaced 19 and repaired. We had, as you recall, the Mojave incident 20 with the steam line break, and the Monroe plant of Detroit 21 Edison steam line break. These are rather dramatic 22 accidents. We went to look at those to see what application 23 they had to nuclear.
24 I called some contacts in Germany following this 25 event and asked what they knew. The first reaction was we
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58 1 don't see any problems here, and I got a call yesterday back 2 that upon digging, they have found enough things so they are 3 putting a study group together to report on the Germany 4 experience, and they will send that to us.
5 So I guess a lot of little failures which were 6 patched when they occurred and just weren't dramatic enough to 7 perhaps get even -- the insurance companies were the first 8 people we talked to to see what experience they could give'us 9 on the fossil side.
10 CHAIRMAN ZECH: There is work under way at both EPRI 11 and INPO. As you have heard, INPO is going to put out an SOER 12 probably in the March-April time frame.
13 COMMISSIONER ASSELSTINE: Will it be a yellow one or 14 a red one or --
15 MR. BOSNAK: I don't know which.
16 COMMISSIONER ASSELSTINE: -- or a green one or 17 whatever the --
18 MR. BOSNAK: I don't know which it will come out to l
19 be.
20 The recommendations from the experts meeting. First 21 of all, as we have briefly covered before, what they are 22 saying is don't make any arbitrary changes to the water l
l 23 chemistry because they recognize that the chemistry that is 24 there now, particularly in the PWR plants, is to protect the 25 steam generators.
1
. . . - - _ - . _ - . - - = . . - - - - . . --
59 1 There were some recommendations with respect to 2 long- term research, that we ought to know more about the 3 effects of pH and oxidizing-reducing environments, and 4 i particularly they brought out the BWR situation, before we 5 make any changes.
6 MR. BERNTHAL: Is it pretty well accepted and do we 7 have a high degree of confidence in the areas of this kind of 8 piping where you have laminar flow that you simply don't have 9 a problem; that it is only in these regions of high turbulence?
10 MR. BOSNAK: It is in the region of high turbulence 11 and all these other variables. If you have streamlined flow 12 in a straight pipe, it is orders of magnitude less. Not to 13 say that wall thinning doesn't occur, but it is down in the 14 noise, you might say.
I 15 MR. VOLIMER: Again, it is a complicated problem, 16 but it sure seems to me that the easier way out on this is to 17 look for a somewhat different steel for those locations where 18 you have especially turbulent flow, and it seems like that is 19 a safer way to go than trying to pin down all these chemistry 20 variables. That's tough.
21 MR. BOSNAK: As you recall, the turbulent flow was 22 also part of the problem with the check valve thing, downstream 23 of orifices and so on. Just ate those up, too.
l 24 So the second area of the recommendation was to 25 present the information to the utilities. We feel we have done
60 1 that in the report of the meetings. It was a summary report 2 and the meeting minutes and also the I&E notices that have 3 come out. They did recommend that whatever data comes back be 4 correlated and processed so that we can refine the guidance, 5 and they also recommended that because the Europeans seem to 6 be well ahead of us in this particular area in studying the 7 phenomenon and what takes place and what is important, to 8 review that.
I 9 Lastly, the ASME is the one technical society that i
10 covers this area, and we have already written to them and have 11 a meeting scheduled on March 19th to discuss what possible 12 courses of action they might take.
13 This is probably a good place to answer commissioner 14 Asselstine's question about inspection requirements. First of 15 all, if you are in this part of the plant, there are no 16 inspection requirements. The only inspection requirements --
17 there is a construction code, and that is the one we alluded 18 to before, B31.1, but there are no requirements for in-service 19 inspection, none.
I 20 COMMISSIONER ASSELSTINE: Typically do utilities do 21 any in-service inspections?
! 22 MR. BOSNAK: Typically, as you heard, they do 23 maintenance inspections, particularly where they have pumps 24 and valves in the lines. Typically they don't look at the i
i 25 pipe, they don't look at the elbows except in the wet steam
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61 1 areas where you have two-phase flow.
2 COMMISSIONER ASSELSTINE: If typically the utilities 3 themselves don't look at these pipes and we haven't required 4 anything, in order to make sure that number two really comes 5 true, why wouldn't you want to issue a bulletin telling 6 utilities to go out and find your susceptible locations and 7 inspect these pipes to --
8 MR. BOSNAK: I think we have something coming up on 9 that, but basically this area is covered by design basis 10 accident, even though we have an accident here, but the effect 11 on workers in the plant, obviously, is not covered.
12 COMMISSIONER ASSELSTINE: Exactly. My concern is
, 13 why have more of these accidents, particularly accidents that l
14 can kill workers in the plant, if you can go out and find the 15 susceptible locations and at least decide fairly quickly 16 whether you have got a thinning condition.
17 MR. BOSNAK: You can do that.
18 CHAIRMAN ZECH: It is certainly something that I 19 hope the Staff is going to --
20 MR. VOLLMER: Well, that is getting ahead a little l 21 bit, but part of our program is (a) to define those locations 22 with reasonable confidence where you can say you should go 23 look, and then secondly, what is the best way to implement the 24 looking? It may be staff bulletin or other action, or maybe l 25 an industry action.
62 1 CHAIRMAN ZECH: This is going to be one of your 2 recommendations today, as far as I am concerned.
3 COMMISSIONER ASSELSTINE: Yes, I agree.
4 MR. BOSNAK: The next slide, please.
5 COMMISSIONER ASSELSTINE: On the question of 6 requirements, let me just ask you how is it that this plant i 7 was in compliance with the first sentence of GDC-17 8 MR. BOSNAK: They had a standard. In other words, i
9 the plant was constructed to a standard, so it met GDC-1. I 10 guess the key was did they continue to meet GDC-1 when the 11 pipe wall thinned.
12 COMMISSIONER ASSELSTINE: That's right. Was it 13 tested? You said there weren't any testing requirements. Was 14 it tested to quality standards commensurate with the importance 15 of the safety functions to be performed by the pipe?
16 MR. BOSNAK: When it was installed, the answer was 17 yes, but after that, no.
l 18 CHAIRMAN ZECH: Let's proceed.
19 (Slide.)
20 MR. BOSNAK: The staff action plan that you see on i 21 this slide indicates exactly what we intend to do as an 1
22 integrated agency. In other words, we have NRR, IEE and 23 Research cooperating to do some of these things. Now, the 24 first set of bullets is the shorter term, and by shorter term, 25 we are talking about four to six weeks.
L
y, I ki
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1 Thismeetingwasearly'inFebruary,sowhatyou'see[ - '
2 ' here should be accomplished by the end of March., N w ,'the f
- . t, ,
3 . first thing that we wanted to do was to complete tho' initial *
-4 prioritization of this particular event,'?and, then also? identify, 5 related generic. issues. This particular event, wd do have?som'a 3 7 p 6 slides on that one coming up. ., t!
7 We have given i si number, but this,i's mncomplicated [
- ~ * ,
8 wall thinning, is what iti amounts to. The industry ~ effort, U
,e ,
j ~w j 9 which is next,-,is the next slide we are going to have.- . That .
I i 10 gets into the feedback that we-have had from the plants.
In ,
I '
- 11 other words, is this occur' ring in many plants or,~1s '
this #
l l
[ 12 something that happens to be right now surry-unifue. " ~
- 13 We are asking the Offica of Research to survey the .
k
- l. 14 international information. As we indicated, thexe is quite a i
- 15 bit of information, particularly in western Europe. We are l 16 going to reevaluate the broad scope rule on leak.before break,
! 17 as I have discussed earlier.
18 We expect to meet with NUMARC,,INPO and EPRI by the ;
19, and of March. With ASME and National consensus codes and- '
20 Standards Body, we have a meeting set up on March 19the ,
21 The longer-term effort is to really decida on some t
22 of these actions which we believe are going to be necessary.
23 There will be some need for additional res.1 arch as we try to .
24 cover. NRR intends to put together a user neod letter to go 25 to Research on the kinds of things we want to h we done.
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64 r
. 1 Thi prioritization of industrial-type events within
- _ 4 2 the design basis envelope of the plant. This is something
{ > ' ', ' x
(?.e 3 that again we havecthese things covered. They are design
, e 4 basis accidents, but how do we consider the effect.on workers Q i ;;
hqip 5 in the plant when we are talking about nonradiological-fluids
,,,4
, 6, that have caused injuries?
is -
J 7 MR. VOLLMER: This is one area that Commission
- e guidance would be helpful because right now we don't have it.
9 You can extend that a little bit beyond hot water in pipes to
' '~, 10 electrical safety, to people falling off of areas of the
, 11 plant. You know, there is a lot of what we used to think of
! c.
? -) 12 sns OSHA-related activities.
i 13, COMMISSIONER ASSELSTINE: Do they do anything in
\
. 14 this area or do they assume that we are taking care of it?
15 MR. VOLLMER: No, they did get involved. Really, i: 16 Virginia handles it. It is not OSHA. They are sort of like 17 an agreement state. So the State of Virginia did handle it, i
g ,
18 and we kept them informed and invited them to our meetings and L ,
19 so on. They did close it out some weeks ago and they no
~
20 longer have any active interest in it.
[
i 21 COMMISSIONER ASSELSTINE: But I would assume you l
22 would not want OSHA in trying to design piping systems or 23 things liks that, or reviewing and inspecting the design of
',24 piping systems, wall thinning, electrical systems, those kinds 25 of things, unless that is what the industry wants, having two 1
s
~
, 65 1 Federal agencias or two agencies in doing that kind of 2 activity.
.3 MR. VOLLMER: No, I do agree with that, but the 4 question is do we have to look at a plant from the viewpoint 5 of worker safety. I mean a worker going by a quarter-inch line 6 that is highly pressurized with hot fluid can be very damaging, 7 too, and at the Surry plant and other plants, there have been a 8 number of steam fatalities and electrical fatalities which are 9 put into the slot as OSHA problems. We need to know from the 10 Commission what areas you feel we need to get into.
11 MR. TAYLOR: The companies have safety programs, you 12 know, for the typical personnel-type of casualty. of course,
-13 that takes care of a lot of things like walkways and the 14 typical electrical shock hazards. In addition, their insurers 15 get into that act, too, so there is not exactly a dead area in 16 plants. It is a typical industrial establishment. I 17 COMMISSIONER ASSELSTINE: What kind of record has 18 this company had in that area?
19 MR. TAYLOR: INPO, by the way, looks at industrial 20 safety also, and that is another one of their charters, to 21 look into that. I believe we have somebody here from Virginia i
! 22 Power who could answer that. I can't answer.
23 CHAIRMAN ZECH: Please come up to the microphone and 24 identify yourself. Thank you.
25 MR. STEWART: I am Bill Stewart with Virginia
, , , , , y , , , , ,_ - - ~ , -
66 4.
1 Power. .On fatalities at Surry, we do have a high number of 2 fatalities. It is now nine. The industrial safety record has 3 been a good record, improving over the years, number one in 4 the Southeast Electric Exchange for company employees that all 5 the utilities share information on. It has been number one in l 6 the Southeast the last two years. We have had nine fatalities.
I 7 Nobody really seems to know what the industry
! 8 fatality numbers are, who keeps them, how many at every plant,
- 9 that sort of thing.
10 COMMISSIONER ASSELSTINE: Okay. But nine for the ,
11 two units over the lifetime of the plants?
1 12 MR. STEWART: Yes. ,
13 CHAIRMAN ZECH: Thank you.
14 Proceed. <
j 15 MR. BOSNAK: There is one other point down here at 16 the bottom of the slide. Some states, and there are nine of l
17 them, have state laws. We mentioned Michigan, the Monroe 18 power plant. The states that have state laws have typically 19 gone in following accidents, called in the National Board as l
l 20 far as doing an investigation is concerned. They have not 21 really been involved in periodic maintenance and that kind of l
22 thing, but there are nine states who have state laws.
23 The results of the survey that I&E undertook.
24 Quickly, it was a preliminary kind of thing and so the results 1
25 may not be complete, but we have 91 plants that responded, I
l t
l . _ _ . _ _ _ _ _ _ ___ __.__ _ _ . . _ _ _ _ _ _ _ _ _ - . . - _,_
67 1 including Surry 1 and 2, and only two that found severe wall 2 thinning in their main feedwater lines.
3 Now, 29 have inspected a number of locations in the 4 main feedwater, and there is no severe thinning. Some have 5 noted thinning but well within the allowable values, and 6 allowable values are set by the construction code. We have 22 7 that still have committed to look, and there are 11 operating 8 plants that we have no commitment from at present. I am sure 9 they are all, as far as I know, intending to do this because 3
10 there is getting under way an industry activity that EPRI and 11 INPO are going to be involved in.
l 12 There are 27 new plants. These are under four years 13 of operation or some of them have not really operated, and of l
14 course, they haven't inspected the feedwater. Down at the 15 bottom there are 38 of the 91 plants that have ongoing 16 programs, and they have identified severe thinning or even 17 repairs to their two-phase wat steam systems.
l 18 This area has a greater potential, perhaps, for 19 injury than the single phase that we have been focusing on.
20 Next slide, please.
21 [ Slide.]
22 CHAIRMAN ZECH: On those 11 plants that haven't made 23 any commitment, I presume that you are going to get a
~
24 commitment from themY 25 MR. VOLLMER: We will wrap up with that, but yes.
4 68 1 The answer is yes.
2- CHAIRMAN ZECH: It better be.
3 COMMISSIONER ASSELSTINE: That's the sixty-four 4 dollar question. You have 33 that haven't done anything yet.
5 You have 22 that have committed to at some point. You have 11 6 that haven't. With 33 plants that haven't done it yet, why 7 wouldn't you want to get a bulletin out saying everybody has 8 to do it?'
9 MR. VOLLMER: Part of the problem not to know has
! 10 been trying to define well enough a point -- and I'm getting a 11 little bit ahead, but what we would like to do is get together 12 with industry and the Owners Group, EPRI is involved, INPO is 13 involved, and work out whether or not we have -- can get from 14 them a timely enough commitment to look at what we feel is l 15 important, and expedite on that basis. If we can't work it 16 that way, then we would issue a bulletin.
17 COMMISSIONER ASSELSTINE: Do you have any questions 18 about the consistency and thoroughness of the ones that have l
l i
19 looked and come back and said, "We don't see a problem"?
20 MR. BOSNAK: No. Again, we don't have all the 21 details of exactly where they looked in their lines. The 22 guidance that went out was for them to look in carbon steel 23 where they had close proximity, and the proximity that was 24 used, if you have a fitting and another fitting next to it, 25 use 10 diameter spacing, which is certainly conservative. If
69 1 the temperature was such that you're in the range, the water 2 chemistry, those were the criteria. And that, by the way, is 3 what is contained in the EPRI White Paper that just came out, 4 those kinds of guidance for where to look.
5 MR. VOLLMER: We're talking about -- you know, most 6 of these things are not very accessible, although they're not 7 in radiation areas, but th'ay are accessible from that point of 8 view. But you're talking about taking the lagging off and 9 inspection process itself --
10 CHAIRMAN ZECH: Yes, but that doesn't prevent a 11 commitment.
12 MR. VOLLMER: No, sir. I agree.
13 CHAIRMAN ZECH: I mean you make a commitment. That 14 doesn't -- you don't have to take any lagging off to make a 15 commitment. So I think we sure ought to let them know we 16 expect a commitment.
j 17 COMMISSIONER ASSELSTINE: Can you get us a list and I
l 18 just send it to us of the 11 plants that so far have refused 19 to provida --
20 MR. VOLLMER: Yes, sir.
l 21 COMMISSIONER ASSELSTINE: Okay.
22 COMMISSIONER CARR: I would'n't say they refused to 23 provide one.
l 24 COMMISSIONER ASSELSTINE: Have not yet provided one.
25 COMMISSIONER CARR: All right.
l
70
.1 MR. BOSNAK: For one reason or another, there is no 2 commitment.
i 3 MR. VOLLMER: This was kind of done informally as 4 well.
5 COMMISSIONER ASSELSTINE: Okay. Did you ask them 6 for a commitment? .
L 7 MR. BOSNAK: No. I don't believe so.
8 COMMISSIONER CARR: The plants'I visited since Surry 9 has happened have all had an ongoing problem in great detail, 10 much more than has been indicated here. -
11 MR. BOSNAK: On this slide that you see in front of 12 you are -- i 13 COMMISSIONER ROBERTS: Did you say an ongoing 14 program?
I 15 COMMISSIONER CARR: Program,-yes. Excuse me. Did I l 16 say problem?
17 COMMISSIONER ROBERTS: Yes.
.18 COMMISSIONER CARR: But maybe it's both, but at 19 least they are on top of it.
20 CHAIRMAN ZECH: Well, the word is certainly out. I 21 visited the plant shortly after this accident and got a pretty 22 good briefing right in the vicinity of a similar type piping 23 system, and they were well aware what happened. They examined 24 their own condition, and were into the metallurgy and the 25 erosion-corrosion business, and all the rest of it. So I
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l
,' 71 l 1 felt, you know, at least for that plant you got the word out 2 pretty well. But certainly it seems to me that we ought to 3 find out why we don't have commitments and I think you should 4- follow through on that rather vigorously.
t 5 MR. BOSNAK: Yes, sir.
6 CHAIRMAN ZECH: Okay. ,
l 7 MR. BOSNAK: Okay. The next slide just kind of 8 indicates the number of generic issues that are in the -- in 9 process. We have one associated with loss of auxiliary 10 fecdwater. This was the steam to the turbine driven aux feed 11 pump. Also within that they've -- that has been subsumed into 12 the auxiliary.feedwater system reliability issue. They have 13 included an estimate of feedwater failure in that, locked 14 doors, GI-81, Generic Issue 57, 83, and finally 139.
I 15 By itself, by the way, 139 had an extremely low 16 effect on public health and safety.
l l 17 Conclusions, the next final one. The first bullet, 18 and probably the most important one, that there will be a 19 program instituted to monitor pipe wall thinning as a measure 20 of what is going on. Whether it will be a cooperative program, 21 we expect that that's what it will turn out to be between NRC 22 and the industry.
'23 Now the second bullet is that pipe rupture is 24 without complications. What we are basically talking about in l 25 the turbine building are design basis accidents with very low I
72-1 public risk. Pipe ruptures from wall thinning and associated i 2 --
3 COMMISSIONER ASSELSTINE: Public? Members of the 4 public?
5 MR. SHERON: Not in prioritization studies. We-a 6 don't -- or in our cost-benefit. We look at workers from a 7 radiological hazards standpoint, in terms of if we require 8 maintenance on something. We would look at the dose that they 9 would receive, but not from nonradiological effects.
10 MR. BOSNAK: Okay. Pipe ruptures from wall thinning 11 and their associated systems interaction, which I think was 12 one of the important lessons that came out of the Surry event, 13 that they are going to be addressed in the generic issues that 14 you saw.
l 15 We do recognize the need to consider wall thinning 16 in the GDC-4 rulemaking in susceptible systems, and when we 17 get into -- further into life extension, obviously it plays a 18 role there.
19 The last one is we have just been discussing the 20 role, NRC's role in protecting onsite personnel from 21 nonradiological hazards needs to be studied, it's currently 22 under study.
23 -
COMMISSIONER ROBERTS: Well, will there be any input 24 from the Office of General Counsel on that? Aren't you 25 getting into some questions of jurisdiction?
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73 _
1- MR.-PARLER: I would think so. Certainly at this 2 point the request that Mr. Vollmer made, that they need 3 additional -- the Staff needs additional guidance.from the 4 Commission in the area. I don't think the Commission can give 5 that guidance withcut further input from the Staff, including 6 the legal office. How is the area that you are talking about 7 in handled in the fossil plants? Is there inactivity by 8 others because there is some confusion as to what this agency's i
9 responsibilities are? That will have to be looked at some 10 place. This is not too much different from the kind of 11 issues that we looked at for the Kerr-McGee and Sequoyah 12 Plant. The resolution there was addressed just to materials 13 licensing.
- 14 The question that you asked is what should the 15 approach be for a nuclear power plant. So before I could 16 advise anybody as to give the advice that Dick asked for, I 17 think we would have to have more input on what the situation 18 is, why, what others are doing, how the situation is handled 19 in fossil plants, et cetera.
20 CHAIRMAN ZECH: Well, it seems to me we ought to 21 start off by asking the Staff to work with OGC and give us 22 some options, at least a spectrum that we can look at and 23 allow the Commission to participate there.
24 MR. PARLER: At the very least, though, in the 25 meantime, if there is some other agency that n ro mally would be t' w t-- ,+,--6 me m-iem.we 3 e e-,-w, . - - m ___ 9
74 i
1 looking into these things, if there is some confusion and they-
.2 -are not looking because they think we are, that should be 3 clarified promptly, in my judgment.
-4 MR. VOLLMER: The direct implications of what 5 happened at Surry and its effect on-other systems, and so on, 6 that we don't need any further guidance to work on that issue l
- l. 7 and get those commitments out. It is a broader issue which I 8 think we need to --
9 CHAIRMAN ZECH: Well, give us a paper on the broader 10 issue and some options, and work with OGC on it.
11 MR.' VOLLMER: We'll do that.
12 COMMISSIONER BERNTHAL: I'm not sure how much 13 discussion there was -- I've had to dip in and out of this ,
l 14 meeting for a bit -- but how much discussion really.was 15 offered on the leak-before-break question. Maybe you want to 16 comment just briefly, but it seems to me that the issue of 17 leak-before-break in the context-the Commission was used to 18 considering that issue was rather different from this 19 circumstance, where we have a massive large area of wall 20 thinning, and you are almost certain you are going to get a 21 massive break, whereas we spend a lot of time at this table 22 talking about stress corrosion cracking, where I suspect that 23 leak-before-break is still a pretty good hypothesis. In a 24 case like this it is clear why you don't get leak-before-break, 25 it seems to me. Do you want to comment on that?
P 75 1 MR. VOLLMER: Well, yes, as we indicated in a couple
-2 of places, the event did undermine -- or directly tends to 3 undermine the leak-before-break on its surface. inunn you look 4 further -- and that's what we are doing right now -- we think 5 that there are some things that clearly we would not allow d
6 under the umbrella of GDC-4, leak-before-break, that would 7 preclude this from happening there.
8 One clearly would-be the materials situation, and if 9 -- and hopefully there would be others. I would hope that 10 there are several things that would put us inside the bounds 11 -- in other words, not just material, but configurations and 12 flow, that would put us well within the envelope of this type 13 of an event in a system that would be covered by 14 leak-before-break.
15 All I can say right now is we are giving a fair look 16 at that.
17 COMMISSIONER BERNTHAL: Okay. But the point that I 18 wanted to stress -- and I don't want to be premature -- is 19 that most of the time we have talked about leak-before-break, 20 it was in the case of the stress corrosion cracking --
21 MR. VOLLMER: Generally that's right, yes.
22 COMMISSIONER BERNTHAL: That is a rather different 23 circumstance, it seems to me, than this particular --
24 MR. VOLLMER: But it also includes --
25 COMMISSIONER BERNTHAL: And PWRs.
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. 76
- l. MR. VOLLMER: And PWRs. But it also includes the 2 dynamic effect, seismic and other dynamic effects that the 3 piping would undergo, but the simple answer would'have been to 4 say well, gee, we wouldn't consider leak-before-break where 5 you have erosion, but on the other hand you say, well, you 6 don't always know if you have erosion. So we have to-look at 7 it, as I said, at least we've got a couple things going for 8 us, and I think materials is probably the strongest one that 9 we can feel comfortable in saying the systems covered by GDC-4 10 before leak-before-break will not be subject to this type of 11 an event.
12 CHAIRMAN ZECH: All right. Are you -- does that 13- conclude your briefing?
14 MR. VOLLMER: Yes, sir.
15 CHAIRMAN ZECH: All right. Questions from my fellow 16 Commissioners? Commissioner Roberts?
17 COMMISSIONER ROBERTS: No.
~18 CHAIRMAN ZECH: Mr. Asselstine?
l 19 COMMISSIONER ASSELSTINE: Maybe just --
20 COMMISSIONER ROBERTS: Well, one comment.
21 CHAIRMAN ZECH: Yes.
j 22 COMMISSIONER ROBERTS: I thought this was a very 23 interesting, well-done presentation.
24 MR. VOLLMER: Thank you.
4 25 CHAIRMAN ZECH: Mr. Asselstine?
4
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77 1- COMMISSIONER ASSELSTINE: I would agrae with Tom's 2 comment. Two quick questions.
3 The GDC-1 questions that I raised earlier, I was a 4 little confused by the answer. Are you interpreting GDC-1
.5 basically to be just through the construction process, up to 6 the point of operation? I always read GDC-1 as going beyond l
7 that and being a continuing program throughout the operating 8 life of the plant. Am I wrong about that?
9 MR. BOSNAK: I believe if we were in another --
10 certainly in another part of the plant where we were in a 11 safety system, yes, then the answer would be definitely yes.
12 But it's in this area of the BOP where we haven't had any real 13 --
14 MR. VOLLMER: If I may?
, 15 COMMISSIONER ASSELSTINE: Go ahead.
I 16 MR. VOLLMER: What we feel is important is that the 17 design basis for the plant be maintained throughout the life 18 of the plant. But as you get further and further away from 19 the safety-related systems and so on, it gets more diffused in 20 terms of regulatory control. But -- and certainly the Staff 21 is concerned and working hard on the balance-of-plant area, 22 but we feel the plar.t should be maintained to its design 23 configuration,. initial design -- FSAR configuration', if you 24 will.
25 COMMISSIONER ASSELSTINE: Okay. Well, that gets me p r,,,.-.my.yy w---,-w.9-wwmyrw,v.w9 -- e.,g a
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78 I to my second question. It seems to me that this is another in 2 a string of fairly clear examples where we see important 3 equipment in the balance of plant that can have a significant 4 bearing on sa'fety, that can either cause or contribute to 5 operating events -- particularly operating events, that if
~
6 they' don't pose a threat to the public, at 1 east they certainly 7 pose a threat to workers to the plants.
8 Isn't this sort of a fairly good example of the 9 reason why we ought to be taking a common sense approach on 10 the balance of plant, to say what is reasonable to ensure that 11 this equipment that can have an important bearing on the 12 safety functions of the plant get the attention that they 13 need, so that we have some basis for assurance that in fact-14 this equipment is going to be maintained in a workable 15 condition throughout the life of the plant?
16 MR. VOLLMER: The answer to that I think is clearly l 17 yes, and I think further than that if the Staff and industry l
18 had from, let's say, fossil experience, have recognized some l
19 of these factors as being important contributors to erosion 20 that could lead to this, we probably would have attacked it 21 earlier, but we just didn't.
22 COMMISSIONER ASSELSTINE: Is this the kind of thing l
23 that would be addressed by the Staff's pro osal on important 24 to safety? That kind of a reasonable, common sense approach 4
25 to dealing with equipment that has a significant safety
.79 1 . bearing?
2 MR. VOLLMER: I think it was the Staff's approach in 3- that, that we would look for normal industrial practice, to 4 use experience, to use manufacturers' guidelines, and industry 5 . handbooks to deal with the balance of plant.
6 MR. PARLER: When you use the word " safety," though, 7 are you intentionally leaving out the adjective before it?
8 Radiological? Is it all-encompassing?
9 MR. VOLLMER: Well, the important to safety, I 10 guess, you know, I think the Staff proposal important for 11 safety went back to what I talked about a few minutes ago, and 12 that is the things that we talk about in the FSAR and --
13 MR. PARLER: Radiological safety.
14 MR. VOLLMER: Well, they are all important to 15 safety, or we probably wouldn't be talking about them in the 16 licensing documents, and so that class of equipment which 17 includes main' feed and other systems like this, we feel have a 18 nexus to safety, and sometimes in obscure, but sometimes in 19 very direct ways. And to that extent --
20 COMMISSIONER BERNTHAL: I think the General Counsel 21 -- he can speak for himself better than I can speak for him, 22 but I think he is referring to not mixing apples and oranges 23 . here, aren't you?
24 MR. PARLER: Yes. If you mix them up, I might be 25 thinking about expanding the 3200, or whatever it is, or l
'80 1- something.
2 COMMISSIONER CARR: Well, there was no indication J3 that they weren't using standard business practice or standard 4 commercial practice in this case.
5~ MR. VOLLMER: That's true.
6 COMMISSIONER ASSELSTINE: What there is an indication 7 of is standard business practice, that is no in-service testing 8 -on this equipment was woefully inadequate. Am I wrong?
9 MR. VOLINER: Where you have certain combinations of 10 conditions that may not have been recognized before, that is 11 the case. But as we get experience, we've got'to use it, and 12 get our lessons learned and get on with it.
13 COMMISSIONER ASSELSTINE: That's all I have.
14 CHAIRMAN ZECH: All right. Mr. Bernthal? Mr. Carr?
15 COMMISSIONER CARR: I've got one question. You said
- 1'6 that -- when you were talking about the first initial 17 detection, there was a small steam release noise heard, 18 followed by a very loud noise, five sounds later. Who heard 19 the small steam release?
'20 MR. PANCIERA: There was one operator standing right i
21 outside. There's a walkway right --
22 COMMISSIONER CARR: So it wasn't in the control
. 23 room? '
24 MR. PANCIERA: He wasn't -- he.was an operator. He I
l 25 was standing right outside the control room. He's the one
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81 o
1 that heard that.
2 COMMISSIONER CARR: All right.
3 MR. VOLLMER: But at the Mojave steam line break, 4 there were two operators near that, and they heard a hissing 5 noise and started running from the site, and hit the deck a 6 few seconds later when that went, and probably saved their 7 life.
8 COMMISSIONER CARR: They have good ears.
9 MR. VOLLMER: That's right.
10 CHAIRMAN ZECH: Well, let me thank the Staff also 11 for a very informative and important briefing. I'd also ask 12 the Staff to follow through on the commitments we have made in l
13 a' couple of areas, and ask SECY to make sure that we don't 14 lose track of this so that we keep it on the list of things l 15 that we are looking for.
16 I, too, would like to emphasize the balance of plant 17 again, because, you know, we recognize-that it can certainly 18 relate to real problems, and so I.think this certainly focuses 19 on the importance of balance of plant.
20 I think that your efforts with industry groups and i
21 also with our overseas nuclear allies is very important in 22 this area, because perhaps as you pointed out, instances at i 23 least similar to this perhaps have happened, but maybe not l
24 very often and haven't gotten much intention. This is the 25 time to focus on that and see if other industries from ours f
82 v:
i 1 have perhaps had similar problems.
2 It's important we follow through on these things, as 3 far as I'm concerned. I think that we almost ought to look at 4 this as rather a starting point than an and point, and I think 5 it's important that we really take advantage of the fact that 6 we've had a tragic accident,' and certainly we don't want to 7 think that those lives were lost in vain, and perhaps we could 8 prevent lives being lost in the future from a very careful 9 look at the whole situation.
10 So I think we'd be derelict if we didn't make a very 11 concerted effort to follow through on these actions, and l
12 perhaps it might be useful to the Commission at some later 13 date to get an update report from the Staff.
14 COMMISSIONER ASSELSTINE: Yes, I agree.
15 CHAIRMAN ZECH: We will do that when you have been 16 able to put things together a little bit more, ecognizing 17 that even that, as far as I'm concerned, won't be an and 18 point, but a following-up action.
19 If there are no other comments from my fellow 20 Commissioners, thank you very much.
I 21 (Whereupon, at 12:00 noon, the meeting was 22 adjourned.]
23 24 25
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2 REPORTER'S CERTIFICATE 3
4 This is to certify that the attached events of a 5 meeting of the U.S. Nuclear Regulatory Commission entitled:
6 7 TITLE OF MEETING: Briefing on Surry Incident (Public Meeting) 8 PLACE OF MEETIN3: Washington, D.C.
9 DATE OF MEETING: Wednesday, February 25, 1987 10 11 were held as herein appears, and that this is the original 12 transcript thereof for the file of the Commission taken 13 f stenographically by me, thereafter reduced to typewriting by 14 me or under the direction of the court reporting company, and 15 that the transcript is a true and accurate record of the 16 foregoing events.
l
' /
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I FIPE PROTECTION SYSTEM ACTUATION-c],
3 UNIT 2 TURBINE BUILDING SPRINKLER SYSTEM ACTilATED
.: 7 3-' 2. CARBON DIDXIDE SYSTEM ACTUATED o WATEP INTPUSION INTO CONTROL PANEL ACTUATED CO2 IF UNITS 1 ANP ? CABLE SPREADING ROOM
- 3. HALON SYSTEM o WATER INTPUSION INTO CONTROL PANEL 4t'iUATED PALON SYSTEM CAUSED HALON DISCHARGE ]f P .;ENCY SWITCHGEAR
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L STATTON PECOVERY J. INSPECTIONS o SCOPE 0 ACCEPTANCE CPITERIA
- 2. COMPONENT REPLACEFENT
- 3. UNIT STARTl!P
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IMMEDIATE STAFF ACTIONS o- DISPATCPED AIT - 12/9/86 c- INITIATED INDEPENDENT FAILURE ANALYSIS 12/12/86 o ISSUED IE INF0PPATION NOTICE 86-106 - 32/16/86 o INFOPPED INDllSTPY OF CONSE0llENCES OF FAILURE o IDENTIFIED PIPE WALL THINNING AS CAUSE o- CONVENED MEET!NG OF TECHNICAL EXPERTS TO UNDERSTAND PHENOMENA CAUSING FAILURE - 1/15/87 o INTERACTION /C00PDINATION WITH INDUSTPY (INPO, EPRI)
AND ASME CONTINUING
- 'o ISSUED SUPPLEMENT 1 TO IE IN 86-106 - 2/13/87 L o PESULTS OF INDEPENDENT FAILURE ANALYSIS o DUCTILE TEARING FAILURE RESULTING FROM OVEPSTRESS CONDITION OF THINNED PIPE WALL DUE TO EROSION-CORROSIOP 0 MATERIAL CPEMICAL AND PHYSICAL PROPERTIES WITHIN l
SPECIFICATION LIMITS
'NPR TECHNICAL MEETING --ON JANUARY-15, 1987-TO DISCUSS GENERIC IFPLICATIONS OF FAILURE o DISCIPLINES REPRESENTED:
PIPING DESIGN,-FLUID MECHANICS,
-METALLURGY, NONDESTRUCTIVE EXAMINATION WATER CHEMISTRY, CORROSION 1
1 0 SURRY-2 FAILURE DUE TO WALL THINNING FROM EROSION-CORROSION e EROSION-CORR 0SION IS FLOV ASSISTED CORROSION, CORROSIVE ACTION IS INITIATED BY EROSION OF PROTECTIVE METAL OXIDE, WITHOUT METAL 0XIDE, CARP 0N STEEL IS VULNERAFLE T0 CORROSION / DISSOLUTION o ACTUAL FAILURE PRODUCED BY SYSTEM PRESSURE TRANSIENT, NOT CLASSICAL WATER HAMMER l
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OFFFRVAT!0NS FPOV TECHNICAL EXPERTS PEETING o PIPING DESIGN - (0#1)
LITTLE. GUIDANCE - SOME AE'S LIMIT BULK FLOW VELOCITY AND USE CONFIGUPATIONS WHICH REDUCE TUPPULENCE o EFFECT ON REVISION TO GDC 4 AND LEAK BEFORE BREAK - (0#2)
EVALUATION FOR LEAK BEF0PE BREAK NOT PERMITTED UNDER MANv CONDITIONS.
- o. VdRIABLES AFFECTING RATE OF ERJSION-CORROSION DAMAGE - (0#3, 0#4)
O COMPLEX SYNERGISTIC RELATIONSHIP o THREE MOST IMPORTANT VAPIABLES L o LOCAL FLUID VELOCITY / TURBULENCE o WATEP CHEMISTPY/PH o MATEPIAL COMPOSITION (CP, CU, Mo)
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SYNERGISTIC RELATIONSHIP OF INFLUENCING VARIABLES ON EROSION CORROSION: ;
AT SURPY VARIABLES ALL UNFAV0PABLE o ELBOW-SPLITTING TEE CONFIGURATION O PH LEVELS OF SYSTEF (8.8 - 9,2) c WATER CHEMISTRY CONTROL DURING OPERATING YEARS o MATERI AL COMPOSIT!0N (LOW TRACE CR <C O,02%)
o SYSTEM TEMPERATURE (IN MOST ADVERSE RANGE) o BilLK FLUID. VELOCITY WAS 17 FT/SEC IN 18" BRANCH o 0XYGEN CONTENT OF SYSTEM APPROXIMATELY 1 PPB TEE ASTM A-106 GRADE B ELB0W ASTM A-234 GPADE WPB PIPE ASTM A-106 GRADE B-REFERENCES F0P FOLLOVING FIGURES HEITMAN AND KASTNEP: EROSION-CORROSION IN WATER-STEAM CIRCUITS -
' CAUSES AND COUNTERMEASURES, VGB KPAFTWERKSTECHNIK, VOL 57, NO, 6, P211, 1982 l
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+ 500 um nickal l .
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mT 500 ug/kg 18Cr stainless .
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g m7 <5pg/kg
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- fact on sion/ corrosion ,ls e ro- l 3a _
(M13 Grade T12) greatest in 266- g S66F range. Condi - 3 -
2 f/4Cr-Mo tions: 580 psig,11'S E .
(A273 Grade 722) ft/sec, pH=7, E I 0,<40 pg/kg, ex-posure time =200 {
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k1 so 0.5 1 i i i i 10 20 30 40 m/sec 32.8 65.6 98.4 131.2 ft/sec !
. Flow velocity, m/see or ft/sec
- 8. Flowing water increases material-loss l rate exponentially with flow velocity.
Conditions: 580 psig,356F, pH =7,0,<5 g/kg, exposure time = 200 hr
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' AWARENESS OF EPOSION AND'EROSTON-COPROSTON - 0#5 e -INDUSTRY AND STAFF HAVE BEEN AWAPE OF EROSION AND EROSIt CORR 0SION'BUT ATTENTION FOCUSED ON SITUATIONS IN WHICH FAILURES HAVE OCCURRED, o TWO PHASE SYSTEMS (WET STEAM) AND SINGLE PHASE SYSTEFS WITH-SUSPENDED SOLIDS ARE THOSE IN WHICH MOST FAILURES HAVE OCCURRED, IE NOTICES, AE0D MEPO, EPPI AND INPO DOCUMEFTS, llTILITY VOLUNTAPY PROGRAMS, AWARENESS DUE TO FAILUPES ,
4 o SINGLE PHASE (SURPY TYPE) - LOW LEVEL 0F AWARENESS DUE TO LACK OF RECORDED FAILURES i
ISSUED SUPPLEMENT #1 TO IE NOTICE 86-106 LICENSEES DETEPMINING WALL THICKNESS t
0 WORK UNDERWAY AT EPRI AND INP0 l
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. RECOMMENDATIONS FROM TECHNICAL EXPERTS MEETING 1, ARBITPARY CHANGES TO WATER CHEMISTRY SHOULD NOT BE MADE.
(PP-AND OXYGEN CONTENT) o- LONG TERM RESEARCH EFFECTS OF PH AND OXIDIZING / REDUCING ENVIRONMENT ON MATERIALS e INVESTIGATE LOCAL. FLilID DYNAMICS IN TYPICAL PIPE CONFIGURATIONS AND EFFECT ON EROSION RATE 2, PPESENT AVAILAFl.E INFORMATION TO UTILITIES S0 THAT THEY CAN UNDEPTAKE PIPE WALL MEASUREMENTS AT SUSCEPTIBLE LOCATIONS AND DETEPMINE NEED FOR PERIODIC MONITORING AND CORPECTIVE ACTION
- 3. CORRELATE AND PP0 CESS AVAILAPLE DATA FROM PIPE THINNING MEASUREMENTS, PEFINE GUIDANCE, REVIEW EUROPEAN WORK,
- 4. ASME o GUIDANCE TO DESIGNEPS VIA CONVENTIONAL PRESSURE PIPING AND NUCLEAR CODES AND STANDARDS ON EROSION, EPOSION-CORPOSION AND CAVITATION IN SINGLE AND TWO PHASE SYSTEFS o S/C XI AND GROUPS ACTIVE IN AGING AND LIFE EXTENSION -
SHOULD CONSIDER MEASUPEMENT '0F PIPE VALL THICKNESS AT PEPIODIC INTEPVALS
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STAFF ACTION PLAN o COORDINATED EFFORT AMONG NRR, IE AND RES c- SHORTER TERM EFFORT IS TO GATHER AND EVALUATE RELEVANT INFORMATION ON INDUSTRY RESPONSE AND ITS SIGNIFICANCE (4 - 6 WEEKS) o COMPLETE INITIAL PRIORITIZATION & IDENTIFY RELATED GENERIC ISSUES o SURVEY INDUSTRY EFFORT - PRELIMINARY REPORT o SURVEY INTERNATIONAL INFORMATION o REEVALUATE GDC u BROAD SCOPE RULE CHANGE (LEAK BEFORE BPEAV) o MEET WITH NUMARC/INP0/EPPI o MEET WITH NATIONAL CONSENSUS CODES AND STANDARDS BODIE c LONGER TERM EFFORT IS TO DECIDE ON NECESSARY ACTIONS, SUCH AS:
o NEED FOR ADDITIONAL RESEARCH 0N EROSION-CORPOSION PPE AND ALSO EFFECT ON LIFE EXTENSION O PRIORITIZATION OF " INDUSTRIAL-TYPE" EVENTS WITHIN DESIGN BASIS ENVELOPE OF PLANT o HOW SHOULD ON-SITE NON-RADIOLOGICAL INJURIES / FATALITIE BE TREATED IN COST / BENEFIT STUDIES - CURRENTLY NOT INC o WHAT IS THE ROLE OF STATES, OSHA IN NON-RADIOLOGICAL EVENTS (ONG0ING EFFORT FROM SEQUOYAH FUELS EVENT) o NEED FOR NEW REQUIREMENTS ON INDUSTRY
7 --
'Q RESULTS OF PRELIMIFARY IE SURVEY ON MA!N FEEDWATER
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91 RESPONDED INCLllDING SURRY 1, 2 i 2~ FOUND' SEVERE WALL THINNING MAIN FEEDWATER (SURRY 1, 2) -
29 HAVE INSPECTED MFW SURVEY DATA INDICATES NO SEVERE THINNING IN MFW 22 HAVE COMMITTED TO LOOK 11- OPERATING PLANTS - NO COMMITMENT AT PRESENT I
27 NEW PLANTS - UNDEP FOUR YEARS OF OPERATION HAVE NOT INSPECTED MFW
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38 PLANTS WITH ONGOING PROGRAMS IDENTIFIED SEVERE THINNING IN TWO-PHASE (WET STEAM) SYSTEMS e
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'f-GENERIC ISSUES THAT WILL ADDRESS IMPORTANT. ASPECTS OF SURRY EVENT GI 68: POSTULATED LOSS OF AFWS FROM TURBINE-DRIVEN AFW PUMP STEAM SUPPLY LINE RUPT!)RE.
SUBSUMED IN GI 124, AFWS RELIABILITY ESTIMATED' ISSUE COMPLETION 11/87 GI 81:- IMPACT-0F LOCKED'D00RS AND BARRIEPS ON PLANT PERSONNEL AND SAFETY REPRIORITIZE GI 83 ESTIMATED REPRIORITIZATION C0FPLETION 12/87 GI 57: EFFECTS OF FIRE PROTECTION SYSTEM ACTUATION ON SAFETY-RELATED E0llIPMENT CONSIDER IN PRIORITIZATION OF GI 57 ESTIMATED PRIOPITIZATION COMPLETION 06/F7 GI 83: CONTROL ROOM HABITABILITY ESTIMATED ISSUE COMPLETION 12/87 1
GI 139: THINNING 0F CARFON STEEL PIPING IN PWR'S ESTIMATED FINAL PRIORITIZATIOP COMPLETION 12/87
- - - , , _ , , , . m. - - . - --c,--.-.- ---,.- , - r - --- -- _ __
k CONCLilSIONS
- c. INSTITUTE A PROGRAM TO MONITOR PIPE WALL THINNING e PIPE RUPTURES WITHOUT COMPLICATIONS ARE DBAs WITH LOW PUBLIC RISK o P!PE RUPTURES FROM WALL THINNING AND' ASSOCIATED' SYSTEMS INTEPACTION WILL BE ADDRESSED IN RELATED GENER C ISSUES o -WALL THINNING WILL ALSO BE COPSIDERED IN:
GDC-4 RULEMAKING DECISIONS PLANT LIFE EXTENSIONS o NRC ROLE IN PROTECTING ON-SITE PEPSONNEL FROM NON-RADIOLOGICAL HAZARDS CURRENTLY UNDER STUDY
-m m,mm TPAHSMITTAL TO: y Document Control Desk, 016 Phillips f'
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ADVANCED COPY TO: The Public Document Room j F
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3 FROM: SECY Correspondence & Records Branch ?l 3 ll 3: "
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m: Attached are copies of a Commission meeting transcript and related meeting 3l ,
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DidMa on Sum _TA ukmk h, 3:
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$! Meeting Date: n1951&l Open # Closed 3 :;
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