ML110200412
| ML110200412 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 01/12/2011 |
| From: | Kent Howard Advisory Committee on Reactor Safeguards |
| To: | |
| howard k | |
| References | |
| NRC-649 | |
| Download: ML110200412 (249) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION Title: Advisory Committee on Reactor Safeguards Plant License Renewal Subcommittee Docket Number: (n/a)
Location: Rockville, Maryland Date: Wednesday, January 12, 2011 Work Order No.: NRC-649 Pages 1-168 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
1 1
2 DISCLAIMER 3
4 5 UNITED STATES NUCLEAR REGULATORY COMMISSIONS 6 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 7
8 9 The contents of this transcript of the 10 proceeding of the United States Nuclear Regulatory 11 Commission Advisory Committee on Reactor Safeguards, 12 as reported herein, is a record of the discussions 13 recorded at the meeting.
14 15 This transcript has not been reviewed, 16 corrected, and edited, and it may contain 17 inaccuracies.
18 19 20 21 22 23 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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2 1 UNITED STATES OF AMERICA 2 NUCLEAR REGULATORY COMMISSION 3 + + + + +
4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5 (ACRS) 6 PLANT LICENSE RENEWAL SUBCOMMITTEE MEETING 7 OPEN SESSION 8 + + + + +
9 WEDNESDAY 10 JANUARY 12, 2011 11 + + + + +
12 ROCKVILLE, MARYLAND 13 + + + + +
14 The Advisory Committee met at the Nuclear 15 Regulatory Commission, Two White Flint North, Room 16 T2B1, 11545 Rockville Pike, at 1:30 p.m., John D.
17 Sieber, Chairman, presiding.
18 COMMITTEE MEMBERS:
19 JOHN D. SIEBER, Chairman 20 SAID ABDEL-KHALIK, Member 21 SANJOY BANERJEE, Member 22 HAROLD B. RAY, Member 23 JOY REMPE, Member 24 WILLIAM J. SHACK, Member 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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3 1
2 NRC STAFF PRESENT:
3 RAJENDER AULUCK, NRR/DLR/RASB 4 FARHAD FARZAM, NRR/DE/EMCB 5 MARK FRANKE, R-11/DRS/EB3*
6 MELANIE GALLOWAY, NRR/DLR 7 ALLEN HISER, NRR/DLR 8 BRIAN HOLIAN, NRR/DLR 9 WILLIAM HOLSTON, NRR/DLR 10 MEENA KHANNA, NRR/DE/EMCB 11 ROBERT KUNTZ, NRR/DLR/RPB2 12 LOUIS LAKE, R-II/DRS/EB3*
13 ALI REZAI, NRR/DCI/CPNB*
14 ABDUL SHEIKH, NRR/DLR/RASB 15 GEORGE THOMAS, NRO/DSRA/SRSB 16 DAVID WRONA, NRR/DLR/RPB2 17 KENT L. HOWARD, Sr., Designated Federal Official 18 ALSO PRESENT:
19 JOHN J. BARTON, ACRS Consultant 20 STEVE CAHILL, FPC 21 MIKE HEATH, FPC 22 JEFF LANE, FPC 23 CHRIS MALLNER, FPC 24 RICHARD PORTMANN, FPC 25 ROBERT M. REYNOLDS, FPC NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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4 1 KEN WILSON, FPC 2 TABLE OF CONTENTS 3 Opening Remarks, Jack Sieber, ACRS 5 4 Staff Introduction, Brian Holian, NRR 9 5 Florida Power Corp. (FPC) - Crystal River 6 Unit 3 (CR-3) 14 7 A. Introduction 8 B. General Plant Overview 9 C. Scoping Discussion 10 D. Application of GALL 11 E. Open and Confirmative Items 12 F. Major Upgrades 13 G. Close 14 NRC Staff Presentation SER Overview 126 15 A. Scoping and Screening Results 16 B. Onsite Inspection Results 17 C. NRC audits 18 D. Time Limited Aging Analyses 19 Subcommittee Discussion, Jack Sieber, ACRS 164 20 Adjournment 170 21 22 23 24 25 26 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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5 1 P-R-O-C-E-E-D-I-N-G-S 2 1:27 p.m.
3 CHAIRMAN SIEBER: The meeting will now 4 come to order. This is a meeting of the Plant License 5 Renewal Subcommittee. My name is Jack Sieber. I'm 6 chairman of this Subcommittee meeting. ACRS members 7 in attendance are Said Abdel-Khalik; Sam Armijo, whom 8 I don't see at the moment; Charles Brown, whom I also 9 don't see; Michael Ryan is supposed to be here, but 10 not; Bill Shack, Harold Ray, and Joy Rempe. Our ACRS 11 consultant, John Barton, is also present. Kent Howard 12 of the ACRS staff is the Designated Federal Official 13 for this meeting.
14 This Subcommittee will review the license 15 renewal application for the Crystal River Unit 3 16 Nuclear Generating Plant and the associated Safety 17 Evaluation Report with open and confirmatory items.
18 We will hear presentations from the 19 Florida Power Corporation, representatives from the 20 NRC staff, and other interested persons regarding this 21 matter.
22 MR. HOLIAN: This is Brian Holian. Just a 23 reminder for people on the phone to put their phones 24 on mute. Thank you.
25 CHAIRMAN SIEBER: We have not received NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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6 1 written comments and request for time to make oral 2 statements from members of the public regarding 3 today's meeting. The entire meeting will be open to 4 public attendance. The Subcommittee will gather 5 information, analyze relevant issues and facts, and 6 formulate proposed positions and actions, as 7 appropriate, for the deliberation by the full 8 Committee.
9 The rules for participation in today's 10 meeting have been announced as part of the notice of 11 this meeting previously published in the Federal 12 Register.
13 A transcript of this meeting is being kept 14 and will be made available as stated in the Federal 15 Register notice. Therefore, we request that 16 participants in this meeting use the microphones 17 located throughout the meeting room when addressing 18 the Subcommittee. The participants should first 19 identify themselves and speak with sufficient clarity 20 and volume so that they may be readily heard.
21 We will now proceed with the meeting and I 22 would like to point out that this is sort of an 23 anniversary meeting, so to speak. The license renewal 24 rule was published as final in 1995 and the first 25 license application to be approved under the rule was NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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7 1 approved in the year 2000. And last year, was 2010, 2 so we have completed 61 license renewals in that 10-3 year period and we have several now pending, but that 4 represents a lot of work by the NRC staff and also by 5 ACRS members in reviewing all of this material.
6 Of the 61 units that were approved, 7 of 7 them are now operating in the license extension 8 period. Those are Oyster Creek, Nine Mile Point One, 9 the Ginna Plant, Dresden 2, H.B. Robinson, Monticello 10 and Point Beach Unit 1.
11 And I would also point out that when the 12 original rules for licensing of plants were decided 13 the term of 40 years was decided more on a economic 14 basis than on a materials issues basis. On the other 15 hand, the plant licenses were written for 40 years and 16 from my own personal experience in having worked in 17 plants that were built, even one of them was started 18 in the 19th century, the management of material 19 degradation is an important aspect of extended life in 20 power plants. And the life extension rule pays 21 particular attention to that.
22 I would point out that one of the 23 attributes of license renewal was use of the Generic 24 Aging Lessons Learned publication and worked on by 25 Argonne National Laboratory and that is in its third NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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8 1 version now. And has been used in one form or another 2 in all of the 61 plants. The Crystal River Plant is, 3 to my knowledge, the last plant that is in a 4 transition between version two and version three of 5 GALL, and that accounts to some extent for the number 6 of open items that remain for this application at this 7 stage in the license renewal process. However, not 8 all of the open items that exist at this time are the 9 result of the transition from version two of GALL to 10 version three of GALL.
11 I have already reviewed your presentation 12 slides and it would appear to me that you are covering 13 one way or another all of the open items with 14 particular emphasis on the containment delamination 15 which we consider to be a serious issue and I request 16 that you pay particular attention to the presentation 17 in that area and your current and future plans for 18 making sure that this important system in your plant 19 maintains its full capability through its current life 20 and its extended life.
21 What I would like to do at this time is 22 introduce Brian Holian of the NRC staff who has been 23 through a lot of license renewals as I have and he 24 will introduce the staff who worked on this and also 25 the presenters from the applicant.
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9 1 Brian?
2 MR. HOLIAN: Thank you and good afternoon, 3 Subcommittee, and thank you, Chairman.
4 My name is Brian Holian. I'm the Director 5 for the Division of License Renewal and I'll just have 6 some brief opening comments and go over the agenda 7 before we turn it over to the applicant for the 8 license renewal.
9 First, I appreciate the comments on the 10 ten-year anniversary of kind of issuing the licenses.
11 We did pause briefly with the staff and recognized 12 that with a little memento for many of the staff who 13 have worked both currently and previously over the 14 years on license renewal. And we did with a note that 15 we gave -- just for the record, repeat it here, that 16 any success in license renewal program really, the we 17 way we view it is how well they operate in that 18 extended period and how well the Aging Management 19 Programs work. So we're continuing to do work on 20 that, even with research now, to see how effective 21 some of these Aging Management Programs are and the 22 Committee will hear more from that in the future, I'm 23 sure.
24 One item on GALL Rev 2, it is Rev 2, it's 25 the third revision but I'll officially call it GALL NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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10 1 Rev 2, since we didn't number GALL Rev 0, I guess, but 2 that did go out in December and we had a very good 3 meeting with the Subcommittee and good comments. It's 4 been received well from the public from what we can 5 tell. So thank you.
6 Other introductions, I'll just start here.
7 To my left is Melanie Galloway, Deputy Director, 8 Division of License Renewal. To my right, Dave Wrona, 9 the Branch Chief in License Renewal that has his 10 project, Crystal River, and several other projects we 11 have in-house. Behind me is Rob Kuntz. You'll be 12 hearing from him primarily later on in the NRC 13 presentation. He's a Senior Project Manager in 14 License Renewal and has the Crystal River project and 15 has had it for the extent of the review. To his left 16 is Meena Khanna and she's a Branch Chief in the 17 Division of Engineering. She's here today also, has 18 been working with the region very closely on just the 19 restart applications, restart issues for Crystal River 20 and the containment issue, in particular, her and her 21 staff.
22 On the phone we have, hopefully, I'm just 23 going to check again, we have Lou Lake, the Senior 24 Inspector at Region II. Lou did the license renewal 25 inspection and also the special inspection, was the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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11 1 lead for the special inspections of the delamination 2 issue of containment. We also have Mark Franke, his 3 Branch Chief in Region II.
4 Lou and Mark, I'm just checking and 5 verifying you're on the phone?
6 They're checking on their mute button and 7 if one of our staff will go ahead and make sure they 8 have the right tie-in code, so we'll do that. Let us 9 know when you're on, but we'll get done and make sure 10 they're tied in. They are snowed in in Atlanta. I 11 guess this is the second or third day that Atlanta 12 with their half inch of snow has shut down the city.
13 (Laughter.)
14 I don't know if that's true. That's what 15 I tell my Region II folks when they can't make it up 16 here. But they did try and we got a few meetings 17 impacted by that, but we'll have folks here on the 18 table that will be able to help on the presentation.
19 MEMBER ABDEL-KHALIK: For the record, it 20 was four inches.
21 MR. HOLIAN: Was it?
22 CHAIRMAN SIEBER: People who live in glass 23 houses shouldn't --
24 (Laughter.)
25 MR. HOLIAN: The agenda for today's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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12 1 meeting, once again, is to hear from the applicant 2 first, take a short break, and then we'll follow up 3 with the NRC perspective on the open items.
4 Today's presentation will be a little bit 5 different than Subcommittees have seen from license 6 renewal in the past, five, six months at least, maybe 7 the final year. We often have issues in license 8 renewal that cross both Part 50 and Part 54 of the 9 license renewal. Examples, we've had buried piping, 10 electric cabling. The Committee often asks what are 11 you doing now on that issue? And we answer with 12 generic correspondence and issues along that way and 13 in these meetings we and license renewal staff 14 particularly look forward to how well and how robust 15 will their Aging Management Program be. Although 16 that's our priority, we try to answer the Committee.
17 We have one big open item, as you 18 mentioned, the containment issue. And we've taken 19 that issue seriously. We delayed this Subcommittee 20 twice. It was originally scheduled for June. We 21 moved it back again to September. We didn't feel the 22 applicant was ready on the issue, mainly in Part 50 23 space, to even come to the Subcommittee. So I just 24 want to recognize for the record that that's been 25 delayed.
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13 1 In some ways this still might be a little 2 bit early from the fact that it's not up and operating 3 yet and the regional perspective and the headquarters 4 perspective is that's the primary issue there. The 5 plant obviously doesn't restart until they've had 6 successful operable containment.
7 The open items that we have today, there's 8 a few open items that the region will talk about until 9 they're satisfied for start up. And then, of course, 10 the license renewal staff will talk about the open 11 items that are also still there until we're satisfied 12 that they have an Aging Management Program that can 13 successfully ensure us that the longer term, aging and 14 operability and containment is effective. The open 15 items for that, you'll see on checking of the vertical 16 cracks, checking of the bulging seam on the liner, 17 even recent inspection from the region identified some 18 cracking in the dome that had been from a previous 19 repair, identified at this outage. The applicant will 20 probably still get another request for additional 21 information from us on have you looked at that for an 22 Aging Management Program incorporated in so far the 23 other cracks that are seen in the vertical buttresses.
24 So we have more work to do. I put that 25 out as a warning for the applicant because it's only NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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14 1 by schedule several months until the final SE is to be 2 finalized, but once again, we'll delay that, we'll 3 delay a final Subcommittee as necessary until we 4 resolve the containment issue and all the open items 5 are satisfactorily resolved.
6 With that, I would just like to turn it 7 over to the applicant. Steve Cahill is Director of 8 Engineering. I'll turn it over to him. Thank you.
9 MR. CAHILL: Thanks, Brian.
10 CHAIRMAN SIEBER: I might ask a question, 11 a couple of questions. The applicant is Florida 12 Power?
13 MR. CAHILL: Yes. In licensing space, we 14 are Florida Power.
15 CHAIRMAN SIEBER: Okay, and that's part of 16 Progress Energy?
17 MR. CAHILL: Yes.
18 CHAIRMAN SIEBER: Which was recently 19 bought by Duke Power or --
20 MR. CAHILL: We announced it.
21 CHAIRMAN SIEBER: You announced it, but 22 you have to get Public Utility Commission approval. I 23 need to know, the licensee is still Florida Power?
24 MR. CAHILL: It's still Florida Power.
25 CHAIRMAN SIEBER: It's very complicated.
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15 1 (Laughter.)
2 MR. CAHILL: We're just trying to make it 3 more complicated.
4 (Laughter.)
5 MR. CAHILL: The first thing I'll do is 6 introduce my team that I have here with me here today.
7 Normally, the first person on my list would be Mike 8 Heath. He's back at the table back here. Here's our 9 supervisor for license renewal. He managed to lose 10 his voice last night very conveniently, so he's giving 11 me most of his speaking assignments.
12 Up here at the table I have Jeff Lane. He 13 is our lead mechanical engineer. I have Chris Mallner 14 who is also a mechanical engineer on our license 15 renewal staff. At the back table I have Bob Reynolds.
16 He is our lead civil engineer. Right next to me I 17 have Ken Wilson. Ken is the supervisor for major 18 projects licensing, so he'll be talking about some of 19 the major projects and aspects we're working on. And 20 also at the back table I have Rick Portman from my 21 normal CR-3 staff. He is my containment programs 22 engineer.
23 Next slide, Jeff.
24 This just covers what we're going to be 25 doing for the agenda today, very high level. We're NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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16 1 going to go through a site description, talk about 2 some license renewal aspects. The opening 3 confirmatory items is the main part of our 4 presentation and as you mentioned we'll be talking a 5 lot about containment in there and then we'll touch on 6 some major upgrades that are going on at the site as 7 well at the end.
8 As far as the site description, Crystal 9 River is a Babcock and Wilcox NSSS plant. They're a 10 BWE plant. We use Gilbert Associates as our 11 architect/engineer and we've been operating since our 12 license was approved in 1976. We are currently 13 licensed for a 2609 megawatts thermal which correlates 14 to about 912 megawatts electric. Ken will be talking 15 about some of our major projects. We do have a power 16 uprate that we're in the middle phases of going 17 through.
18 Some key features about Crystal River, we 19 are pressurized water reactor. We feature a very 20 large dry containment. We have once-through steam 21 generators, both of which were just replaced in the 22 outage that started last fall.
23 We use the Gulf of Mexico as our ultimate 24 heat sink. We're actually part of the Crystal River 25 energy complex, so there's four COL units there.
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17 1 Units 1 and 2 are very close, adjacent to Unit 3 and 2 they share the actual discharge intake canal where we 3 use the Gulf of Mexico as our heat sink.
4 We do have helper cooling towers in our 5 discharge canal and they are primarily just to 6 mitigate the point of discharge temperature effect.
7 So they're not used except in the peak days of the 8 summer when temperature for all three units operating 9 becomes a peak.
10 At this point I'll turn it over --
11 CHAIRMAN SIEBER: Before you switch 12 slides, I do have a question. You have four COL units 13 and a nuclear unit there. Are there any shared 14 systems between the nuclear unit and any of the COL 15 units?
16 MR. CAHILL: There are some shared systems 17 and the point of there's things like some water like 18 our distilled water, demineralized water, those are 19 some shared systems that are operated outside of our 20 fence. But we do maintain, I guess, oversight and 21 operating of them. So aside from that and just 22 electrical ties, there's really not many shared 23 systems. We also get our auxiliary steam from Units 1 24 and 2, but there's a line of demarcation there.
25 CHAIRMAN SIEBER: The auxiliary steam, is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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18 1 that -- any of that safety related? If that line were 2 isolated or not available, would it affect the 3 operation of Crystal River 3?
4 MR. CAHILL: No, it would not.
5 MR. BARTON: What happens when both fossil 6 units are down, Crystal River is down, you need aux.
7 steam to get started. How do you do that?
8 MR. CAHILL: We would have to basically 9 come in and use an auxiliary boiler.
10 MR. BARTON: Get an auxiliary boiler, 11 bring it on site?
12 MR. CAHILL: We've not had that situation.
13 We always maintain --
14 MR. BARTON: It's a possibility.
15 MR. CAHILL: It's possible. Looking long 16 term at Unit 1 and 2, the longevity of those plants, 17 that is something on our long-term horizon.
18 MR. BARTON: I was wondering whether it 19 would be decommissioned before Unit 3, which would 20 create that problem.
21 MR. CAHILL: We've been exploring what 22 type of auxiliary boiler system we would put in place 23 if they were decommissioned.
24 MR. BARTON: Units 1 and 2 also have some 25 off-site power, DC control power with some breakers.
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19 1 And that DC control power is located in Unit 1 and 2 2 battery rooms.
3 How does Unit 3 maintain control or assure 4 that those systems are well maintained, since it is a 5 power source?
6 MR. CAHILL: We do maintain some control 7 of that.
8 Bob, you want to take that question? Bob 9 has some more details on that beyond just my general 10 answer.
11 MR. REYNOLDS: Yes, I'm Bob Reynolds, lead 12 civil. And we included those portions that come from 13 Unit 1 and 2 in the scope of license renewal. There's 14 battery rooms, battery racks, conduit cable tray, 15 supports that come from Units 1 and 2 over to the 16 switch yard. And what we would use to do that is the 17 monitoring program which will do the inspections on 18 that facility and those components. And similar to 19 what we do with the rest of our plant, we would 20 initiate corrective actions if we find degradation of 21 any of the components in the system.
22 MR. BARTON: Thank you.
23 MR. REYNOLDS: Yes, sir.
24 CHAIRMAN SIEBER: Now you basically use 25 one-through cooling on Unit 3 or condenser cooling?
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20 1 MR. CAHILL: Yes.
2 CHAIRMAN SIEBER: With an auxiliary 3 cooling tower. And the water intake comes from the 4 Gulf of Mexico?
5 MR. CAHILL: Yes.
6 CHAIRMAN SIEBER: Were you affected at all 7 by the BP oil spill?
8 MR. CAHILL: No. We had several 9 contingencies in place and we were looking for any 10 effects of that, but it did not have any impact on us.
11 CHAIRMAN SIEBER: The cooling towers, they 12 basically circulate and cool water from the Gulf of 13 Mexico. That's where it's origin is?
14 MR. CAHILL: The helper cooling towers you 15 are referring to?
16 CHAIRMAN SIEBER: Yes.
17 MR. CAHILL: Yes, they're actually solely 18 located on our discharge canal and they are just there 19 to cool down the discharge after it has left Crystal 20 River Unit 3. So it really doesn't interface directly 21 with the Unit 3 at all.
22 CHAIRMAN SIEBER: How do you deal with 23 chlorides? Because if you're operating a cooling 24 tower, water vapor is leaving distilled. All the 25 chlorides end up in the basin.
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21 1 MR. CAHILL: I'm not really familiar with 2 it. They operate very infrequently.
3 Do you have any more information on that, 4 Jeff?
5 MR. LANE: This is Jeff Lane, lead 6 mechanic. As a matter of operating the plant, I can't 7 speak to how they blow down or what they do with that.
8 As a matter of license renewal, they're not in scope.
9 MR. BARTON: I think the issue Jack=s 10 bringing up, though, is what comes out of those 11 cooling towers is salt-laden vapor. And what effect 12 does that have on equipment at the site, for example.
13 Does it affect the transmission yard, the switch 14 yard?
15 CHAIRMAN SIEBER: That has been a 16 significant issue on the east coast of Florida. There 17 are studies done by NASA at the Cape Canaveral 18 installation and salt plume travel actually goes for 19 miles and does affect the nearby equipment became an 20 important issue in spent fuel storage cask 21 construction and age life determinations. It's got to 22 have some effect on the equipment at your plant.
23 MR. CAHILL: The helper cooling towers and 24 I cannot give you specific details, they operate very 25 infrequently, usually only in the very peak months of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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22 1 the summer, like I said, when we are temperature 2 limited and that usually is only the case when all 3 three units are running, Units 1, 2, and 3, 4 simultaneously. And that's usually only a matter of 5 days at a time.
6 When truthfully, for your question, the 7 more relevant concern would be Units 4 and 5 use 8 hyperbolic cooling towers that are right next door to 9 us. We have not had any issues really with the salt 10 from that. We do have to monitor salt and clean off 11 things in our switchyard periodically, but that salt 12 is primarily associated with weather events coming in 13 from the Gulf.
14 CHAIRMAN SIEBER: I brought the satellite 15 photograph maps of the site. It seems to me you have 16 five cooling towers there, right?
17 MR. CAHILL: We have two main hyperbolics, 18 that's Units 4 and 5 and then the other cooling towers 19 are these little helper ones which are on the 20 discharge canal.
21 CHAIRMAN SIEBER: Okay. Why don't you 22 continue on?
23 MR. CAHILL: Okay. At this point, I will 24 turn it over to Jeff.
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23 1 mechanic lead. I'll talk a little bit about the 2 process that we use to develop the license renewal 3 application of Crystal River. I'll point out that 4 Crystal River license renewal applications are four 5 license renewal applications. We formed our license 6 renewal project around the year 2000. We put together 7 four teams to do that.
8 The initial application was the H.B.
9 Robinson Plant application. That team developed that 10 application, stayed together through the review of 11 that and then subsequently the development and review 12 of the Brunswick and Harris license renewal 13 applications. So Crystal River applications is 14 basically our fourth application.
15 Our staff has been heavily involved in 16 administering Working Groups for license renewal.
17 Staff members have chaired both the Mechanical and 18 Electric Group meetings in recent years. We've also 19 been involved in the development of the revisions to 20 NUREG-1801, provided input on the front end and 21 comments to the draft revisions for NUREG-1801.
22 Recognizing that the site will ultimately 23 inherit our Aging Management Programs, we did get the 24 site involved in the review of Aging Management 25 Programs and the development of that part of the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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24 1 application. Plant staff were responsible for the 2 review of all the Aging Management Programs that 3 eventually they will inherit.
4 From a process standpoint, our application 5 was developed consistent with the regulatory 6 requirements of 10 CFR 54, as well as based on NEI 95-7 10 industry guides. Our sources of information 8 included our equipment database which is a quality 9 control database for Progress, design basis documents, 10 plant procedures, final safety analysis report and 11 document correspondence.
12 And aging management reviews, again, they 13 were also consistent with regulatory requirements and 14 industry guidance. We did extensive reviews of plant 15 operating experience and utilized that in both 16 developing the Aging Management Reviews and Aging 17 Management Programs and we made consistency with GALL 18 a priority in the development of our Aging Management 19 Review and Programs.
20 We'll spend just a minute and talk about 21 GALL consistency. Our application was based on NUREG-22 1801 Rev. 1. That was the revision that was current 23 at a point in time that put together the application.
24 Based on Rev. 1, our application has roughly 82 25 percent consistency with GALL Aging Management Review NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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25 1 line items. Consistency in this regard being standard 2 notes A through D, Tab 41 Aging Management Programs, 3 17 programs are consistent with GALL; 22 programs have 4 exceptions or enhancements.
5 There are two plant-specific programs, one 6 of them relating to fuel pool reactor neutron global 7 monitoring and the other related to high-voltage 8 insulators in 230 kV switchyard.
9 Relative to the exceptions associated with 10 our 22 programs, a number of those are related to 11 upgrading our programs in recent months, to go from 12 Rev. 1 to meet the requirements of Rev. 2 of NUREG-13 1801.
14 A brief overview of our time-limited aging 15 analyses in the application. We had TLAA associated 16 with the reactor vessel neutron embrittlement, metal 17 fatigue, environmental qualification of electrical 18 equipment, containment tendon prestress, containment 19 liner plate, metal containments and penetrations 20 fatigue and a plant-specific PLA relative to bedrock 21 dissolution from groundwater.
22 Commitment management. At present, we 23 have 30 license renewal commitments. We are tracking 24 these commitments and using Progress Energy's 25 commitment tracking process. This is the same process NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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26 1 that we've used for both the Harris and Brunswick 2 plant as well as Robinson which recently completed its 3 IP 71003 inspection process and extended operation 4 last August.
5 Basically, this process develops an 6 implementation plan for each commitment. Each 7 implementation plan will identify all the activities 8 required to satisfy that commitment and a piece of 9 those activities is entered into our Corrective Action 10 Program.
11 We'll go the open items and confirmatory 12 items as part of our presentation. At this point, 13 I'll turn it back over to Mr. Cahill.
14 MR. CAHILL: Thanks, Jeff. Okay, as we 15 discussed before, we'll be covering our opening and 16 confirmatory items and the one on the cover is the 17 containment delamination. So I've got a sub-agenda 18 there. This is basically the scope of what I'll be 19 covering as we go through containment.
20 I'll talk about the root cause. I'll talk 21 about basically the overview of the repair that we 22 have done. I'll talk briefly about the impacts that 23 we have assessed and seen on the liner. I'll talk 24 about our liner bulges and then we'll just go through 25 in the detail, very details of our pre-startup and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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27 1 post-startup inspections, as well as our monitoring 2 and overview program.
3 The first slide is really just to get us 4 oriented. This is actually a picture after the steam 5 generator placement opening was created and before we 6 have done any repair efforts. So as you can see 7 there, the opening is right there in the middle.
8 There's a yellow outline there that shows the actual 9 scope of the delamination. This was after the efforts 10 for condition assessments which I'll talk about in a 11 minute defined it. But just to get you oriented 12 before we did any excavation efforts, that is the 13 scope of the delamination.
14 If you notice, the extent of it is 15 mitigated up at the top. That's where the ring girder 16 reinforcement limited the scope of the delamination.
17 I'd just also to point out this area between the two 18 buttresses, the buttresses being on the left and right 19 side of that opening, we call these bays. I'll be 20 referring to this as Bay 3-4 because that is between 21 Buttresses 3 and 4. As you can see at the bottom of 22 the picture that is our equipment hatch down there 23 that was not selected for taking the steam generators 24 out.
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28 1 by who? The design of containment, the design of the 2 containment building?
3 MR. CAHILL: The design was done --
4 Gilbert was our IE. Worley Parsons -- we go back to 5 him for our design records.
6 MR. BARTON: Parsons?
7 MR. CAHILL: Yes. I can note, too, this 8 root cause I'll be discussing here, we presented this 9 in public forums a couple times before we were up here 10 on June 30th talking with the staff about our plans 11 for the repair and so forth and at that point the root 12 cause is completed. And we also just had a public 13 exit in September for our special inspection team 14 where we also went through this.
15 So I'm going to have a few slides to give 16 a basic overview of the root cause. I've got the 17 problem statement up there. I will not read that, but 18 that problem statement really reflects what we knew at 19 the time when we started this investigation. As we 20 found what we were looking at, we really understood 21 that we needed to have a pretty comprehensive effort 22 going forward.
23 So we pulled together a very comprehensive 24 team to conduct this root cause. A lot of Progress 25 Energy personnel, we actually tapped their expertise NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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29 1 across the fleet, brought a lot of folks down from our 2 Carolina sites as well as headquarters to help us out 3 with this effort. And they've been dedicated to that 4 effort since and they're still engaged.
5 We use a lot of industry peers as well.
6 We had some other utilities providing civil and 7 containment expertise. Folks who had actually been 8 employed by Worley Parsons in the past and had a lot 9 of knowledge of our type of containments.
10 We also went externally. We had to tap a 11 lot of external expertise. Industry vendors with 12 civil pre-stress containment and engineering analysis 13 expertise. And then there was extensive effort to 14 pull both for field data obtaining as well material 15 lab support. We did a lot of data reviews, a lot of 16 data was obtained for this and there was a lot of 17 testing that was done to support both the root cause 18 as well as our subsequent repair efforts. So those 19 are a significant part of our team.
20 This next slide is a graphic to get in a 21 little more details so there's I guess a consistent 22 understanding what we're talking about when I say 23 delamination. This is a cross section of our 24 containment wall. The outside of containment being on 25 the lefthand side. Note that the dept of our NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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30 1 containment is about nominally 42 inches of concrete 2 and there's a 3/8ths inch steel liner on the inside of 3 that.
4 This graphic does depict the tendon sleeve 5 so as you can see these are horizontal tendons which 6 run in pairs and then you can see a little deeper in 7 on the inside plane of those is where the vertical 8 tendons run.
9 I'd also like to point out, note that 10 there is a complete lack of reinforcement inside the 11 plane of the tendons. There is no structural rebar in 12 that plane inside of the tendons.
13 There are a set of outer map rebar, number 14 8 bars that were part of the original design, mostly 15 just to resist thermal cracking, though they're small 16 bars, number 8s and that was just on the outside plane 17 beyond the tendons.
18 The delamination is depicted there. It is 19 the red line. You can see it and it is run 20 consistently in the plane of the horizontal hoop 21 tendon, so it's nominally about 9 to 10 inches deep 22 from the outside of containment.
23 Any questions on this before I move on 24 because this is an important one and I want to make 25 sure everybody understands what we're talking about?
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31 1 The next slide just talks about our 2 overall strategies as we approach this. We really had 3 four main teams. Obviously, we had a dedicated team 4 for the root cause analysis, but we had to have one 5 for condition assessment. There was a pretty 6 significant effort just to understand the scope of 7 what the problem was that we were facing. Also, 8 dedicated team we had for design basis analysis.
9 We had a team charter from the very 10 beginning of this effort to make sure we understood 11 all the aspects of our design basis and what we were 12 going to be doing in both the investigation and repair 13 to make sure we could maintain that and restore it.
14 We also had a team looking at repair 15 alternatives because quite frankly in the early end 16 stages of this, we didn't understand the full scope of 17 it. We really assessed a lot of different ways of 18 repairing this.
19 The condition assessment came first though 20 because it really fed the root cause in the design 21 basis analysis. And I point out the yellow box in the 22 middle. This is very key. We recognize very early on 23 that we had to reconcile any of our repair efforts and 24 our reconstitution, I guess a restoration of our 25 design basis. It had to be reconciled with the root NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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32 1 cause. So we had to understand this well enough to 2 make sure that we could understand what we were going 3 to do to repair it and make sure we could do a proper 4 restoration.
5 As I mentioned before, next slide, initial 6 focus was on condition assessment. In the condition 7 assessment, we chartered a team to determine the 8 depth, the extent, and the boundary of the 9 delamination. That was primarily done a lot with non-10 destructive testing of the containment wall surfaces.
11 The primary method we went of selecting and using 12 going forward was impulse response method. We took 13 over 8,000 impulse response data points throughout the 14 wall.
15 MEMBER SHACK: What is this technique?
16 MR. CAHILL: Impulse response, it's a 17 company, CTL Labs, Concrete Testing Laboratory. It's 18 a technique that they had where they actually use a 19 calibrated hammer and basically put a pulse into the 20 wall and they have a measuring -- basically listening 21 devices and the result they get out of this is called 22 a mobility factor. From that calibrated hit with the 23 hammer, they can see how it travels and where it hits 24 things and basically there's a lack of mobility as 25 that pulse moves through the wall.
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33 1 MEMBER SHACK: Is the sensor on both 2 surfaces?
3 MR. CAHILL: No. It's totally done on the 4 outside, so it's complete non-destructive evaluation.
5 So you've got people set up on the outside and you 6 basically have at a set spot with sensor locations set 7 up that they take this measurement. So it's a 8 tedious, you go through discrete points going through, 9 but -- I was going to mention going forward, you might 10 wonder well, how can I get anything from that?
11 Because it doesn't give you, it doesn't give you a map 12 or anything like that. It gives you a mobility 13 number.
14 And a mobility number has to mean 15 something. We took a significant amount of core bores 16 through our containment, over 170 of them in total at 17 the end. We had to use those to calibrate this 18 technique on our specific wall to make sure we knew 19 what we were seeing with this mobility factor, 20 otherwise, it would just be a meaningless number.
21 MEMBER SHACK: And so you saw a dramatic 22 change in the mobility number as you went from the 23 cracked region to the --
24 MR. CAHILL: Yes. We spent a lot of time 25 with the staff, with the specific inspection team NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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34 1 going through the basis for that and the validity for 2 that. I think we've done a very good job and have a 3 very credible basis for saying that that is a 4 calibrated technique that we can use in places without 5 a lot of reinforcement. We can't do this in a heavily 6 reinforced area of the wall. But we have fairly clear 7 path to do this. We can detect delamination very 8 reliably.
9 MEMBER SHACK: And your 8,000 data points, 10 how many of those are over the cracked area and how 11 many are over in one cracked area?
12 MR. CAHILL: You saw the outline before 13 that I drew. The comprehensive scan. We did 14 comprehensive scanning pretty much in the entire 15 containment, all 360 degrees of it. There's a few 16 isolated and inaccessible areas we couldn't get to, 17 but again, we shared that. It was a very big focus of 18 the special inspection team was our extended condition 19 to make sure we knew where we had delamination and 20 where we did not. So we essentially scanned the 21 entire containment using this technique.
22 CHAIRMAN SIEBER: So you operate this 23 device, you get a readout and that readout tells you 24 that there's an interface at a certain distance, is 25 that what it is that you're looking at?
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35 1 MR. CAHILL: It's not really calibrated to 2 measure very good with distance, but it can tell you 3 whether you have basically a delamination or a crack 4 there in that same plane.
5 There's other techniques that we have that 6 would be more precise in distances.
7 CHAIRMAN SIEBER: Let's same the 8 delamination is 50 square feet, how does it know the 9 difference between that and just the other side of the 10 wall?
11 MR. CAHILL: I probably am not the right 12 one to get into that, the detail, but we did calibrate 13 that. If you look at the core bore mass we've taken, 14 you will see the outline of the delamination. You'll 15 see a large majority of our core bores were taken 16 right inside that edge, right outside the edge. And 17 you can clearly tell the difference between the two.
18 Rick, do you know any more about that?
19 CHAIRMAN SIEBER: These are questions we 20 have to ask and you have to answer so we will have 21 developed enough faith to believe that your method is 22 reliable and viable and tells you meaningful 23 information you can act on and perhaps perform a 24 repair or do an analysis. If it doesn't give you 25 distance, I'm not sure how you're going to do any kind NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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36 1 of an analysis.
2 MR. CAHILL: It's calibrated only in a 3 certain depth of distance. It basically can't detect 4 -- it's basically not useful past about a 12-inch 5 depth. So knowing that our plane had delamination, we 6 were going after a targeted phenomenon in that plane.
7 CHAIRMAN SIEBER: You said it's useful 8 only to about a 12-inch depth?
9 MR. CAHILL: The way it's calibrated and 10 set up. I'm --
11 CHAIRMAN SIEBER: How thick is your 12 containment?
13 MR. CAHILL: Forty-two inches.
14 CHAIRMAN SIEBER: So anything beyond 12 15 inches, you don't know anything about.
16 MR. CAHILL: You can set it up to 17 basically more targeted for different areas the way 18 it's set up. We calibrated it and did it 19 comprehensively on containment for the delamination 20 phenomenon we were trying to bound.
21 CHAIRMAN SIEBER: Now is this instrument 22 given credit by any of the ACI, American Concrete 23 Institute, or any national society or international 24 society that endorses this as a way to attest to the 25 integrity of concrete?
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37 1 MR. CAHILL: I am not familiar with the 2 level of endorsement it has.
3 CHAIRMAN SIEBER: Is the staff prepared to 4 discuss these kinds of qualification details that we 5 would have to have?
6 MR. LAKE: This is Lou Lake. Can anybody 7 hear me?
8 CHAIRMAN SIEBER: Yes, sir.
9 MR. CAHILL: Yes.
10 MR. LAKE: This is Lou Lake. I was the 11 lead inspector on the special inspection as well as 12 the license renewal as stated previously. To answer 13 your question, the special inspection team had a 14 member, Dan Noss, from Oak Ridge Lab and he was very 15 familiar and has presented this methodology of doing 16 concrete inspections at a number of international 17 seminars. He had attested to us that it was 18 satisfactory in doing this inspection and determining 19 the extent of the delamination.
20 MEMBER ABDEL-KHALIK: If there were 21 another crack, let's say 20 inches deep, parallel to 22 the one that you depict in this picture, would this 23 technique be able to detect both?
24 MR. CAHILL: If you had cracks on top of 25 cracks you say?
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38 1 MEMBER ABDEL-KHALIK: No, cracks parallel 2 to --
3 MEMBER SHACK: In a different region, if 4 you had a crack at a different depth.
5 MR. CAHILL: My understanding of it, yes, 6 you would be able to see that. You would see a 7 difference in mobility factor. I mean you get very 8 consistent results when you have solid concrete and 9 when you don't you will get a change of mobility 10 factor. The delamination was where it was at the 11 depth that we were nominally looking it. It was very 12 consistent.
13 A lot of other places we had results in 14 the periphery of the delamination and so forth or in 15 other places, we actually found some -- I guess some 16 anomalies left over from original construction that 17 were at different depths. We found that from laser 18 scanning and actually did core bores to excavate those 19 out and assess those, so we would see those things on 20 the IR scans, but the only way to validate exactly 21 what you've got is to go basically take a core bore.
22 And we did that extensively. There's probably almost 23 like 15 different places. We took core bores 24 specifically just to investigate something we saw from 25 an IR scannability fact, the number was not consistent NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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39 1 with the solid concrete.
2 CHAIRMAN SIEBER: I would just ask the 3 staff to provide the Subcommittee with technical 4 documentation so we can make an independent assessment 5 of the accuracy and the value of this instrument for 6 doing the kinds of tests that you're describing.
7 MR. CAHILL: I sort of mentioned this 8 already, but taking the concrete core bores, we also 9 use boroscopic inspections. When you take a core and 10 you're looking for a delamination somewhere in a 11 plane, the core that you actually extract is usually 12 somewhat damaged and it's not a very good correlation 13 of what you found. So each one of those core bores, 14 we actually went in boroscopically and did a visual to 15 make sure we could see along the length of that core 16 bore, exactly what we were seeing.
17 Again, I say these were used as a primary 18 means as a prime standard to calibrate to make sure 19 that we were getting valid readings from our IR 20 readings. And also, we took a lot of core bores for 21 various material testing.
22 MEMBER SHACK: Was the core bore intact 23 the same way you do well logging?
24 MR. CAHILL: You take a core bore --
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40 1 cylinder.
2 MR. CAHILL: The bore cylinder you get out 3 is not always -- sometimes you'll get, if you take a 4 long bore cylinder, it will crack just from the 5 physical shock of taking the core bore. So we never 6 relied upon that. We relied upon actually going into 7 the hole that was left in containment with a boroscope 8 to be able to see exactly what the 360 circumference 9 of the core we left, what there was in there. So 10 looking for a crack that way.
11 The last thing, we took a lot of material 12 testing out of the cores we've taken. We've retained 13 a lot of those cores for future testing and trending.
14 MEMBER SHACK: Was the radar useful?
15 MR. CAHILL: The radar was primarily only 16 useful, it's a very limited technique, and it was only 17 useful for finding embedded objects. When we took a 18 lot of these core bores there was a lot particularly 19 outside of the repair area. We still have tendons 20 energized. So there was a lot of physical safety 21 aspects of taking a core in those areas.
22 So we used the GPR mostly for physically 23 locating our tendons, as kind of a redundant 24 technique. We use several techniques to make actually 25 sure where we're taking a core. So many cores we took NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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41 1 were fairly deep and long and even at an angle 2 sometimes. You have to have certainty. It would be 3 very catastrophic to drill into an energized tendon.
4 That's primarily what GPR was used for.
5 CHAIRMAN SIEBER: In any of the core bores 6 that you took, did you find any embedded objects that 7 you did not expect to find, like pieces of wood?
8 MR. CAHILL: Not in the core bores. And 9 you'll see in the later pictures, we did extensive 10 amount of concrete removal in Bay 3-4 as part of the 11 repair. And we found that there was large, extensive 12 amount of different pieces of field fit like angle 13 iron and so forth, really just put there that were not 14 there for structural reason, but they were put there 15 for mostly setting the tendons in place and things 16 like that before they actual concrete pours. So a lot 17 of those things are not on engineer drawings because 18 they weren't engineer features.
19 So there's really nothing that we found 20 that was from your perspective like big pieces of wood 21 or things like that that would be a problem that would 22 be unexpected. Those things were expected, but we 23 didn't always know what we would find.
24 We used Performance Improvement 25 International as our root cause lead. I'll refer to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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42 1 them as PII from here on. They applied their 2 proprietary methodology to the effort that we went 3 under for this investigation. It uses failure modes.
4 So at the beginning of this we defined 75 potential 5 failure modes. This is 75 different options that 6 really anything that could be considered that could 7 possibly have led to this event.
8 Of that 75 potential failure modes, we did 9 conclusively refute 67 of them. That left eight that 10 could not be conclusively refuted. Of those eight, 11 they were combined to basically look at relative 12 significance and assess for the root and contributing 13 cause determination.
14 One of the notable discoveries very early 15 on in this investigation though is that existing 16 techniques we had that we used that many other 17 utilities have used to actually make the opening for 18 the steam generator placement, they continued to 19 predict excessive margins to delamination. They did 20 not show stresses being exceeded that would have 21 predicted this delamination event that we had.
22 So very early on in this effort we 23 realized that we needed to develop new finite element 24 analysis tools to be able to go and basically model 25 this phenomenon and be able to predict it with an NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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43 1 engineering tool.
2 Those models progressively got more and 3 more complex. When we started out, we realized very 4 early on that we had to do a 360 degree global model.
5 We could not do a symmetric and only cut it in half.
6 But very early, we realized that just the standard 7 finite element analysis techniques with displacements 8 and stresses could not accurately model and predict 9 this phenomenon, so we went to a visco-elastic non-10 linear model to be able to build this model that could 11 actually model cracking and the propagation of that.
12 So that led to basically two different models. We 13 have a global overall model and we have a much more 14 detailed sub-model which uses a much smaller mesh to 15 get more fine resolution on localized areas to be able 16 to mimic this behavior.
17 And really just having the condition 18 assessment results behind us, knowing the extent that 19 what we got for this delamination and the resultant 20 pattern, that was really -- we needed to have that.
21 We could not have built this model and had it 22 calibrated without actual event data.
23 The overall conclusions though for our 24 root cause was that our design was acceptable for 25 normal emergency operations. There was nothing we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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44 1 found that jeopardized that fundamental basis. We did 2 find that our construction was all done in accordance 3 with our design, so there was no construction 4 deficiencies that did not meet our design 5 requirements.
6 We also confirmed, which the staff agreed 7 with, with our special inspection team conclusion was 8 the delamination occurred during the outage, during 9 the opening of the steam generator placement opening.
10 As I mentioned before, we had to develop 11 the state-of-the-art techniques to be able to analyze 12 this response and to recreate within the reliability 13 computer model.
14 MEMBER ABDEL-KHALIK: Where do you get 15 constitutive relations for these visco-elastic models?
16 MR. CAHILL: Where do we what?
17 MEMBER ABDEL-KHALIK: Where do you get 18 constitutive relations for these visco-elastic models?
19 MR. CAHILL: Constitutive relations? I --
20 MEMBER ABDEL-KHALIK: Right. Just 21 essentially that relate the properties, the behavior 22 of this material, the visco-elastic behavior.
23 MR. CAHILL: We use an ABACUS-based model 24 that ABACUS is the vendor that built this model and 25 with the testing we --
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45 1 MEMBER ABDEL-KHALIK: ABACUS has a visco-2 elastic model?
3 MR. CAHILL: Yes, they do. This is a 4 specialized application of it that has been basing 5 this model. Their tool has been customized for 6 Crystal River PII. PII has been the vendor to do that 7 to look and be able to recreate this delamination with 8 the specialized mode and using ABACUS as the 9 underpinnings of that.
10 PII has been the vendor that's been 11 performing that and like I said, they could not have 12 done that without the data we have for the 13 delamination and the pattern that had exhibited as 14 well as the material test. And we took extensive 15 material testing and a lot of fracture tests and took 16 a lot of fracture energy tests and an extensive amount 17 of tests which I have a laundry list of them which I 18 can go through which some of them, I don't even fully 19 grasp what you're getting out of them. But PII did 20 those things to basically build this model.
21 I'm not real conversant at I guess the 22 level of detail you probably want to know for how they 23 built it.
24 MEMBER SHACK: But this is a specialized 25 concrete model that they develop for you using the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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46 1 constitutive models within ABACUS and there's a bench 2 primarily against your experience, not wider use for 3 other reasons. This is really a customized --
4 MR. CAHILL: Exactly. It's a customized 5 model of CR-3's containment and that is our prime 6 standard.
7 MEMBER SHACK: Not the geometry. As Said 8 -- in the constitutive model, in the concrete model, 9 this is something that they've used widely?
10 MR. CAHILL: ABACUS has used this before.
11 It's not something that has not been used in the 12 past. I'm not familiar with I guess the detail of the 13 question you're asking as how they map that to our --
14 MEMBER SHACK: Not a structural guy here.
15 MR. CAHILL: No. Sorry, I can't give you 16 much more detail on it than that.
17 CHAIRMAN SIEBER: In your conclusions, the 18 third one down says delamination occurred during the 19 outage. Could you describe to me, first of all, the 20 mechanism for the delamination? What caused the 21 delamination to occur? And could you describe to me 22 why you believe that it occurred during the outage?
23 MR. CAHILL: The mechanism was going 24 through and looking through the stresses that were 25 created for the actual opening of the SGR opening. I NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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47 1 mean that's where -- those stresses did not exist when 2 we had tension containment to start with.
3 CHAIRMAN SIEBER: What caused those 4 stresses?
5 MR. CAHILL: That actual sequence and 6 opening of the -- detensioning of those tendons, the 7 17 tendons that we detensioned, the horizontal tendons 8 and vertical tendons that were detensioned in the 9 opening of that SGR opening. That created a very 10 significant change in the stress profile there which 11 traditional analysis would have said was acceptable 12 and met working stress requirements.
13 CHAIRMAN SIEBER: Don't you have 14 procedures for tensioning and detensioning? Did you 15 follow those procedures?
16 MR. CAHILL: The procedures are for the 17 actual physical acts of it. We actually had to go and 18 -- you don't have procedures that tell you how to 19 detension significant amount of tendons. Containment 20 is not designed, not intended for that. We had to do 21 an engineering change, a formal engineering change to 22 support that evolution for the steam generator 23 replacement. So that was an analysis that Sargent and 24 Lundy did for us to look at the actual structural 25 aspects of detensioning those tendons to support the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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48 1 effort that we did to open up that containment 2 opening.
3 CHAIRMAN SIEBER: So that analysis, since 4 delamination did occur that analysis was faulty?
5 MR. CAHILL: Yes. It was not faulty, but 6 it also was not --
7 CHAIRMAN SIEBER: You did the analysis so 8 it wouldn't happen and then you went and did the 9 activity and it did happen, so something goes to be 10 wrong.
11 MR. CAHILL: It did not go down to that 12 level of detail to be able to model this. Some of the 13 things that propagate delamination are just some small 14 existing cracks that exist with our design with our 15 tendons. We have a very small -- we have a smaller 16 amount of tendons compared to some other containments, 17 so you have some nominal micro cracking that exists on 18 top of the horizontal tendons to begin with.
19 Without having a refined niche, you don't 20 model that localized behavior, so a typical element 21 analysis like Sargent and Lundy did for us wasn't done 22 to that level of detail. And even then when we did 23 that level of detail, we still could not get I guess 24 the propagation mechanism without going to a visco-25 elastic model to be able to get to a delamination NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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49 1 phenomenon.
2 CHAIRMAN SIEBER: So there's at least one 3 maneuver that you know that you can do that will cause 4 delamination that you could not predict in the past.
5 MR. CAHILL: There's one --
6 CHAIRMAN SIEBER: This event occurred, 7 even though you did an analysis. The analysis did not 8 predict delamination, but delamination occurred. The 9 only way you found it is because you disassembled the 10 area to make the opening to change the steam 11 generators. Otherwise, you wouldn't even have found 12 it.
13 MR. CAHILL: Well, we did for the initial 14 phases of opening, we have confirmation they did not 15 exist beforehand. And we presented all this to the 16 staff in the past why we had that level of confidence.
17 So I really wasn't prepared to get into some of the 18 details that you get with the root cause. The staff 19 has concurred with that and did do a lot of 20 investigative work with the evidence we had at the 21 time to confirm delamination could not have been 22 pre-existing.
23 CHAIRMAN SIEBER: I guess I have to be 24 convinced before I can vote on your application.
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50 1 had a lot of other cracks in the concrete. Does this 2 impulse response method detect those other kinds of 3 cracks, too?
4 MR. CAHILL: No, it's not really 5 particularly well suited for that. It's well suited 6 for going through and finding something that's I guess 7 in the plane of the surface that you're going against.
8 Some of these other cracks which we'll get into some 9 details of what we found and what we've done about 10 them and impulse response is not really very well 11 suited to give you a crack basically in the same plane 12 of the direction that you're taking the reading in.
13 MEMBER REMPE: So its orientation is not 14 the size of the crack?
15 MR. CAHILL: Yes. The orientation has a 16 big impact on the ability -- to be able to do -- we've 17 been struggling with a good non-destructive evaluation 18 technique to be able to accurately predict the crack 19 that's in the same plane of the direction you're 20 looking in. IR is very good for reliability 21 predicting, detecting delaminations.
22 Let's go to the next slide.
23 MEMBER ABDEL-KHALIK: I guess I'm just 24 trying to follow up on an earlier question. Of these 25 170 core bores, I guess you were able to see by just NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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51 1 going with the boroscope and seeing what the crack is 2 inside. Did any of these show a crack at a different 3 depth?
4 MR. CAHILL: Not a delamination crack, no.
5 No, not a delamination crack.
6 MEMBER ABDEL-KHALIK: Regardless of what 7 you call it, did any of them show a 360 crack at any 8 other depth?
9 MR. CAHILL: No, not something to that 10 extent. There were some places we took localized core 11 bores because we had like a void and containment just 12 from original construction and a different bay outside 13 of our repay bay, so we find things like that when we 14 took some of these core bores. But nowhere else did 15 we see another true delamination from taking a core 16 bore. The cores that we took validated our IR scans 17 showing the delamination. It saw something on the 18 ability factor, we would go take a core and we would 19 see about nine or ten inches. We'd see a 360 20 delamination crack. And depending on where you took 21 those in the different areas of containment, as we 22 detension containment further to help facilitate the 23 repair, that delamination opened up as we took some of 24 the pre-stress away from all those tendons. So it 25 varied in width in some of those locations in Bay 3-4 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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52 1 where we took I guess probably most of our core bores.
2 To answer your question, that was pretty 3 consistent. We saw the delamination and really 4 nothing else. We never saw -- that would be a 5 delamination if we saw 360.
6 MEMBER ABDEL-KHALIK: Right, that's what 7 I'm trying to get to.
8 MR. CAHILL: No. We did not see anything 9 other than delamination phenomena that we were looking 10 for here. And that's why I made the point of drawing 11 that picture on the very first slide. We have 12 extensive, as I said in these presentations before, 13 we've gone into very deep detail and some of my staff 14 have been there to support exactly where each of the 15 core bores was, what the extent of delamination was, 16 in a lot more excruciating detail than I was planning 17 to do here. But it confirmed, like I said, with the 18 scans and cores through all six phases of containment.
19 It confirmed that extended delamination was only in 20 Bay 3-4 and was within that pattern that I showed you.
21 That was a very simplistic version of it. I have a 22 lot more detail. We actually brought in IR scans.
23 With the mobility numbers is they varied across all 24 containment we presented in our previous public 25 presentations.
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53 1 MEMBER ABDEL-KHALIK: You indicated that 2 there were 75 potential failure modes and of those 67 3 failure modes were refuted?
4 MR. CAHILL: Yes.
5 MEMBER ABDEL-KHALIK: What was the basis 6 for refuting those failure modes?
7 MR. CAHILL: Physical evidence or testing 8 results. Like a failure mode could have been like we 9 had an inadvertent building spray actuation many years 10 ago. That could have possibly caused a slight vacuum 11 being pulled on containment. That was something that 12 was investigated thoroughly and the evidence was put 13 in place to refute that that could not have been. And 14 that was in the category of operational events.
15 There's things like external events. Could a 16 hurricane have done this? So those are the type of 17 things. I mean some are very obviously unlikely 18 failure modes, but they were all considered. That's 19 the methodology PII proposes or does is lay out all 20 these potential failures modes and you can't take them 21 off the table until they've got something to refute 22 them.
23 MEMBER ABDEL-KHALIK: I'm trying to 24 understand the difference between the word mode and 25 the word initiating event.
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54 1 MR. CAHILL: It's probably somewhat 2 synonymous for the sake of this discussion. Something 3 that potentially could have caused this event.
4 Really, no rock was left unturned looking for 5 different things to put on that failure mode's list.
6 So that was a significant amount of effort. The 7 beginning was just to go through a lot of our 8 operating history and the history of the containment 9 to make sure that we had considered all the potential 10 possible things that could have been out there.
11 You've got to recognize, when we first saw 12 this, nobody had ever seen this before. It was a very 13 unknown, there was not a lot of expertise to rely 14 upon, so we cast a very wide net looking at what 15 potentially could have been the cause of this.
16 Just on the summary for the root cause 17 though, if the root cause was a combination primarily 18 of inadequate detensioning scope and inadequate 19 detensioning sequence, that caused us to exceed our 20 tensive capacity in those areas and caused this 21 delamination to occur. But there were several failure 22 modes that were not refuted, so some of those were 23 attributed as contributing causes. So there's 24 multiple of those that contributed to delamination, 25 but the root cause was described as the detensioning NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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55 1 sequence and scope because if we had not done that, we 2 would not have gotten into this event.
3 But some of those other contributing 4 causes I mentioned are design. I touched on that 5 before. Compared to some other similar pre-stress 6 containment designs, we have a fewer number of 7 tendons, so we tend to have a slightly higher stress 8 concentration just because we have more force on each 9 of those individual tendons.
10 MR. BARTON: Is that the reason you think 11 you had the problem in other plants that have a 12 similar containment that they had to cut a hole in 13 containment to replace steam generators did not 14 experience this?
15 MR. CAHILL: That is one of several. And 16 other containments, other containments have done 17 similar detensioning scope and sequence like we did.
18 Others have a detension further and taken more of that 19 pre-stress out. So we've looked at every single other 20 steam generator replacement opening and tried to 21 compare those. That was a lot that was put into 22 building the failure, the potential failure modes.
23 But another one key contributing cause was our 24 aggregate. This is an issue the staff has discussed 25 at length with us.
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56 1 We use a Florida limestone-based 2 aggregate. It is clearly not as strong as a northern 3 granite-based aggregate. It met all of our design 4 requirements though, that's a key thing that we looked 5 at to make sure that we were not outside of our design 6 basis.
7 MR. BARTON: Did you say the concrete is 8 somewhat different than other containments with 9 similar design?
10 MR. CAHILL: Yes. So those things added 11 up to get -- basically, give us the higher potential 12 for this to happen. But ultimately, it would not have 13 happened and there was no design problem until we went 14 through this specific detensioning scope and sequence, 15 which we could not have predicted based on the tools 16 as you mentioned.
17 CHAIRMAN SIEBER: Wasn't there some plant 18 years and years ago that ended up with relaxation of 19 these tendons that caused containment problems? I 20 would have to look through my operating history 21 records, but it seems to me I remember something like 22 that. I don't remember it resulting in delaminations 23 in concrete, but there are mechanisms where tendons 24 can detension through --
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57 1 things like that. That's why we keep testing them to 2 make sure that we understand their --
3 CHAIRMAN SIEBER: And do you retension 4 your containment tendons from time to time? Or do you 5 check that?
6 MR. CAHILL: We check that as part of our 7 normal program, our containment inspection program 8 checks those tendons periodically on given intervals.
9 We've not retensioned any of them. I'll talk about 10 what we're doing at this outage.
11 CHAIRMAN SIEBER: You have actually 12 checked the tensions as part of your surveillance 13 program?
14 MR. CAHILL: As part of our surveillance 15 program and you have, I guess, the time analysis as to 16 how they're going to behave over time and you're 17 checking to make sure they correlate with that. That 18 was an extensive part of our investigation was looking 19 at the results we had previously had to see if there 20 was anything from those previous surveillance results 21 that indicated something that we had a phenomenon 22 going on that could have caused this delamination.
23 That was also refuted.
24 CHAIRMAN SIEBER: Do you recall the 25 periodicity of the checks you make on the tendon NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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58 1 tension?
2 MR. CAHILL: So that I don't get the facts 3 wrong, I'll let Rick Portman answer that because that 4 is his program. He is the one that is accountable for 5 making sure those periodicities and that surveillance 6 program is met.
7 CHAIRMAN SIEBER: Before we even do that, 8 do you take credit in your on-going life extension for 9 the program you have to check the tension of tendons?
10 That could be a part of the solution to this problem.
11 MR. CAHILL: Yes, that program is credit 12 and license renewal credited. It's an existing ASME 13 program.
14 CHAIRMAN SIEBER: Let me -- you can let 15 your colleague speak in a little bit more detail about 16 this.
17 MR. REYNOLDS: Crystal River Containment 18 IW/IWF program manager. For our surveillance for the 19 tendons, every five years we do a percentage of our 20 tendons and test them for lift off of forces and we 21 project those over the life of the plant. And our 22 current projection is that they will be above the 23 minimum requirements for the next 60 years.
24 CHAIRMAN SIEBER: What was your findings 25 the last time you did this?
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59 1 MR. REYNOLDS: Last time we did this was 2 in 2007. And we had a few that were below the 95 3 percent requirements at the time. Since then we've 4 also gone back and taken a look at our calculations 5 that we use for that input and some of our creep 6 values that we were using at the time, we have since 7 changed and gone back and looked at everything that 8 we've done in the past was above the 95 percent level.
9 CHAIRMAN SIEBER: Okay. You have a couple 10 instances where you had to re-tension?
11 MR. REYNOLDS: Yes. We had a few that 12 fell below the 95 percent and retensioned them up to 13 the predicted values.
14 CHAIRMAN SIEBER: It's my recollection 15 that Crystal River 3 is not unique among those that 16 have this type of those tension concrete containment 17 vessel. Are you familiar with other plants that are 18 of similar design to yours? This is not a unique 19 situation, right?
20 MR. REYNOLDS: I don't believe it is, no.
21 CHAIRMAN SIEBER: Okay. I don't know for 22 sure, but I don't believe it is either.
23 MR. CAHILL: Anything else?
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60 1 know that it's unique, but you are somewhat different 2 in design, apparently.
3 MR. CAHILL: Yes. There's a difference 4 and that's one of the things we looked at is what made 5 us different. We didn't realize that several other 6 containments just have more tendons to disperse to 7 individual forces.
8 MEMBER SHACK: Are there others who have 9 as few as you?
10 MR. CAHILL: It's not -- I mean -- do you 11 know the answer to that, Rick?
12 MR. PORTMANN: I believe we have less load 13 factors as our tendons are actually physically larger, 14 therefore we have less than others, larger wires.
15 MR. CAHILL: As far as raw numbers go, I'm 16 not sure -- I can't answer that off my head. It's 17 looking at basically how much you have in a given 18 area. We saw our design was on the low end of that.
19 MEMBER ABDEL-KHALIK: Maybe we can ask the 20 staff to answer that question when the time does.
21 MR. CAHILL: Going back to the root cause 22 slide though, the one other one contributing cause I 23 did mention was I mentioned that in the slide show in 24 the graphics before. We didn't have any radial 25 reinforcement in this area. It was not part of our NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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61 1 original design, so that was also something that some 2 other containments had some differing degrees of that 3 and we saw that as well as the contributing cause.
4 That was not a design problem for us until we went 5 through this detension sequence.
6 So in summary, we did a pretty thorough 7 and detailed root cause investigation. Recognized our 8 containment was not designed for the scope of the 9 detensioning that we did and going through that 10 evolution, in the manner in which we did, was what 11 caused the delamination.
12 I'm going to switch now and talk a little 13 bit about more going forward in the repair phases.
14 Just up there, an overview of six different phases.
15 This plan was developed after a lot of exploration, 16 like I mentioned before of various repair techniques.
17 Most of those techniques would have been much less 18 complex and a lot less time consuming.
19 We look at things like doing a grout 20 injection of the repair to fill up the delamination.
21 We looked at various anchorage methods, basically 22 putting a different type of Hilti bolts or anchors or 23 grouted anchors in to basically pull that delamination 24 back together and structurally restore that by.
25 We looked at epoxy injection as an option.
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62 1 Really, going through all those, we decided that none 2 of those would have given us the confidence and the 3 clear path to say that we have fully restored our 4 design, design and licensing basis. So all those were 5 rejected and we came up with a plan that I'll be 6 talking about going forward.
7 So each of these things were driven by our 8 Corrective Action Program. This was a formal root 9 cause investigation we did in our Corrective Action 10 Program, so all of these things were driven by the 11 corrective actions coming out of the root cause that 12 PII developed for us.
13 Our overall big picture work load shows 14 five engineering phases. There are formal engineering 15 products driving each part of that. So basically up 16 there on the slide I have Phases 1 through 5. Each of 17 those has an associated engineering change or EC in 18 our language driving that.
19 The first three phases were documenting 20 removal and mitigation. We did a stress relief cut.
21 That was basically before we started any work. We 22 actually made a cut in the containment to make sure 23 the extent of our delamination, now that we had 24 defined it, did not get worse or we did not create a 25 new delamination.
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63 1 Then we went through a very detailed 2 detensioning sequence. We had to have PII use our new 3 model to actually --
4 MEMBER ABDEL-KHALIK: So the yellow line 5 that you have on this photograph, is this boundary 6 determined through measurements? Or is it determined 7 through modeling?
8 MR. CAHILL: Measurements. That boundary 9 was dictated by our condition assessment which was the 10 IR, the impulse response technique, as well as our 11 core bores. So that was what determined what that 12 boundary was and what the scope of our delamination 13 was, those efforts.
14 MEMBER ABDEL-KHALIK: What would the 15 model predict for the boundary of this region?
16 MR. CAHILL: As I said before, the model 17 had to be largely built -- we needed something to 18 calibrate it against and it was calibrated -- that was 19 our prime standard, our benchmark for that model was 20 that actual physical artifact we had left after this.
21 So when you say what would it have predicted? It is 22 set up to basically predict that.
23 MEMBER ABDEL-KHALIK: So the model is not 24 an EPRI model that would have told you what the extent 25 of delamination --
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64 1 MR. CAHILL: There was nothing existing 2 and we did go out and look when we realized that the 3 existing tools were not adequate to predict this.
4 There was nothing out there that was an off-the-shelf 5 model or tool that could have accurately predicted 6 this. And that was part of the initial phase of the 7 investigation with PII was looking for other 8 techniques that could have helped us with this.
9 We went through all the other vendors who 10 had ever done these -- worked for steam generator 11 replacement openings looking for other techniques that 12 they may have used that we were not aware of and could 13 not find anything going forward working through those, 14 as well as with folks like EPRI. So that's why we 15 built this model based on the ABACUS tool to be able 16 to accurately model this.
17 MEMBER ABDEL-KHALIK: I'm just still 18 trying to understand then what is the purpose of the 19 model?
20 MR. CAHILL: The purpose of the model was 21 one, to be able to replicate it, but we've used that 22 model extensively to go through the second phase of 23 this detensioning. When we made -- when we decided 24 the scope of our work was going to be remove this 25 delamination, we had to detension all the tendons NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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65 1 pretty much in the repair area. That's a significant 2 amount of tendons that had to be detensioned.
3 And knowing that detensioning those 4 tendons is what caused this event in the first place, 5 we would have been proceeding blindly unless we had an 6 analysis technique to be able to predict what was 7 going to happen next.
8 CHAIRMAN SIEBER: Would it not have been 9 appropriate to detension the entire containment, do it 10 in phases so as to balance the stresses in the 11 concrete structure? Is that what you did?
12 MR. CAHILL: Detensioning is a significant 13 devolution to a containment.
14 CHAIRMAN SIEBER: I understand that.
15 MR. CAHILL: In our analysis, we looked at 16 the scope of that and came up with -- our experience 17 has been every time we go further with delamination we 18 wind up creating more problems. So that was something 19 that was considered as a possible scope, that the 20 sheer amount of that effort and the challenges that 21 would have created with basically completely relaxing 22 containment would have -- with where we were to start 23 with which was the SGR opening, a delamination place, 24 we elected not to go down that path.
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66 1 be the stress relief, detensioned in the area that you 2 wanted to work, and on what do you rely since you 3 created the new stress pattern, you probably don't 4 know exactly except by analysis which means you don't 5 know exactly, how do you know that the damage didn't 6 spread?
7 MR. CAHILL: After we did detensioning, we 8 did comprehensive further scanning to make sure and 9 I'll be talking more about the scanning we're going to 10 be doing to make sure we did not get delamination 11 elsewhere. But we used this model to basically come 12 up with a detensioning sequence. It was a very 13 precise sequence and nowhere near a normal tendon 14 tensioning sequence per the industry standards, 15 precisely set up by PII using this model to make sure 16 that we did not get a perpetuation of this 17 delamination.
18 CHAIRMAN SIEBER: Detensioning is usually 19 done sequentially and in stages. It takes a long 20 time.
21 MR. CAHILL: It's usually done, optimized 22 for moving platforms up and down a site of 23 containment, it's optimized for the workers.
24 CHAIRMAN SIEBER: To minimize the stress.
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67 1 because it was very inefficient what we did for 2 detensioning as well as for what we're doing right now 3 for re-tensioning is very inefficient as far as from a 4 work point of view. But it's all done to make sure 5 that we are staying within the bounds of what this 6 tool predicts.
7 CHAIRMAN SIEBER: I don't think you have a 8 choice.
9 MR. CAHILL: Exactly.
10 MEMBER SHACK: Just in the sequence, 11 somehow I make the cut and then I detension, so my gut 12 tells me I want to detension first before I cut. What 13 would I exactly cut?
14 MR. CAHILL: The cut was really just an I 15 cut within that outline that I showed you before, 16 within the delamination area. It was basically to 17 give a stress relief path when we took more of the 18 stress out because there was still a lot of tendons 19 fully tensioned going through that area.
20 So with the initial analysis we did, we 21 realized that there was a potential for it to grow 22 further and we did not want to give it that. As that 23 stress was relieved by detensioning those tendons, we 24 wanted it to be relieved through this cut. Sot it was 25 a very simple evolution of just basically making an I NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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68 1 saw cut in there and it worked very well. We saw 2 that's where the stress relief came when we 3 detensioned tendons further. So that was why that 4 sequence was set up that way.
5 I'll cover some more details on this in 6 subsequent slides. The next phase is the concrete 7 placement, number four, and re-tensioning, number 8 five. We've considered those our restoration phases.
9 And those are the bases for our final engineering 10 changes and our design basis restoration that the 11 staff has been very B- has been interacting with us on 12 how we get back to restore and say that we can do 13 this. Because we're doing it via 50.59 approach.
14 CHAIRMAN SIEBER: Let me ask a question 15 here. You made the opening which means you had to 16 remove some tendons and rebar and all kinds of stuff.
17 You replaced all that after you went through these 18 maneuvers to try to limit the delamination and to 19 remove it to the extent that you can. Now the rebar 20 patterns and the tensioning cables, are they 21 consistent with the design of the remainder of the 22 containment in that these are all post-tensioned and 23 not heavily rebarred to say here's a flat plate in an 24 otherwise flexible membrane?
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69 1 condition or is there something new or extra or 2 something missing in the latest -
3 MR. CAHILL: You'll see this in going 4 forward that we considered this a significantly large 5 repair. We changed a lot of the actual physical 6 features in this, but one of the reasons again not 7 detensioning the entire containment was to not take --
8 we had to very early on decide how far we were going 9 to take this to set the starting parameters for the 10 new repair design and as you'll see, we put a lot of 11 rebar and reinforcement into the repair bay, but 12 basically on that starting point, knowing the sequence 13 we would go to restore it.
14 CHAIRMAN SIEBER: I saw the slides.
15 That's why I asked the question. It looked like more 16 rebar than I'm used to seeing in a post-tension 17 containment under construction. So my question again 18 is is the rebar design in other pictures in the 19 section that you replaced different than the original 20 design?
21 MR. CAHILL: Yes.
22 CHAIRMAN SIEBER: And if it's different, 23 does it have different stress strength characteristics 24 under, for example, seismic conditions, pressurized 25 conditions? How does the redesign of that section NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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70 1 affect the remaining sections?
2 MR. CAHILL: We've done several formal 3 analyses and calculations.
4 CHAIRMAN SIEBER: Okay.
5 MR. CAHILL: We used another vendor, MPR, 6 is one we relied on heavily to do analysis for that 7 looking at -- really literally now we'll have a much 8 stiffer Bay 3-4 because of the amount of reinforcement 9 it has there with a significant amount of new 10 concrete. So we did look on the effects of adjacent 11 bays, on our liner. We have several formal 12 engineering analyses and calculations that the staff 13 has reviewed in detail. We've had a lot of 14 interactions with Meena's civil staff on each of those 15 individual changes and looking at the technical 16 validity of each of those going back to what our 17 original design basis was to make sure that it wasn't 18 invalidated.
19 So yes, it is a big change from that 20 perspective because the other bays don't have that 21 level of reinforcement. But we did a lot of 22 engineering work to support that.
23 CHAIRMAN SIEBER: The reason why I did 24 look through the slides that come after this one, it 25 seemed to me like the rebar design that I saw depicted NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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71 1 in the slides was more like standard containment, as 2 far as rebar density and spacing is concerned as 3 opposed to my memory of what post-tension containments 4 look like in their skeletal structure. Is that a 5 correct impression?
6 MR. CAHILL: Yes. And a lot of that had 7 was dictated by the design with a starting point where 8 we were on the stresses that the design team was faced 9 with with the amount of detensioning we did where you 10 start from to get it back to the final pre-stress 11 levels.
12 CHAIRMAN SIEBER: Now did you do an 13 analysis that examined the whole containment, perhaps 14 finite elements or otherwise with these two different 15 methods of construction combined together to see how 16 the containment would act as a whole?
17 MR. CAHILL: Yes. Both where PII has done 18 for us and just looking at a re-tensioning sequence, 19 but really, the design basis work that MPR has done 20 for us has done that, has looked at from a finite only 21 point of view. We have several formal calculations 22 and analyses and as a part of our engineering change, 23 those last two I mentioned about concrete placement, 24 it has analyzed all that and we've been reviewing it 25 with the staff to make sure that we still stay within NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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72 1 our original stress strain characteristics for the 2 original design basis. So that has been done.
3 CHAIRMAN SIEBER: You were able to do this 4 all under 50.59?
5 MR. CAHILL: And we had a lot of 6 discussions with the staff on that.
7 CHAIRMAN SIEBER: More than a two-page 8 report.
9 MR. CAHILL: I also mentioned we were here 10 on June 30th. We had a very long meeting with the 11 staff just to lay out the approach and the strategy 12 for that. And that's not -- we're not done yet, so 13 there is always the chance that the staff -- that's an 14 open question on the 50.59. We're still working 15 through those.
16 CHAIRMAN SIEBER: Your responses answered 17 some of my questions, but not all. I will have to do 18 some homework on my own. Why don't you continue?
19 I think the members will see what I'm 20 talking about when they look at these photographs that 21 we have on the slide.
22 MR. CAHILL: As I mentioned, I made the 23 comment before that a lot of this work had to be done 24 to -- it had to be informed by the root cause and 25 that's really the reason why. We needed to understand NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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73 1 that phenomenon before we could make sure we had the 2 design confidence to make sure we went forward with 3 this.
4 The next slide kind of touches on what 5 we've been talking about, but our overall conclusion 6 was that this is a summary coming out of our design 7 basis team that our containment design features that 8 remain unchanged, we've done this via 50.59. I mean 9 obviously some of the actual physical features have 10 been altered, but we think we've been able to make a 11 very sound case that we can do that under 50.59.
12 We maintain our original containment 13 design basis. We still have a leak-tight structure to 14 contain fission products in the design-basis loss-of-15 coolant accident and that's really done by an elastic 16 response to the design basis loading preserved to 17 protect the liner. The liner is the ultimate fission 18 product barrier that this entire structure is designed 19 to protect.
20 So all of our design loads and 21 combinations are based on our accident and not local 22 code requirements and we continue to apply the same 23 load factors, provide safety margin. So we 24 verified that all our stresses and strains stay within 25 our design and licensing basis.
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74 1 We sort of touched on this already, but 2 our delamination repair was after the cut, we 3 detensioned containment. We took 155 horizontal 4 tendons and 64 vertical tendons, actually detensioned 5 them and removed them from their sleeves. This 6 detailed sequence analysis as I mentioned before that 7 PII had to develop out of their model for us.
8 Pretty much all the tendons in the repair 9 area of Bay 3-4 have been removed. There's still some 10 on the right periphery and up by the ring girder that 11 are still in their locations and as you can see in 12 subsequent pictures, we did not remove those.
13 The delamination was fully removed. That 14 was the initial charter of this. The initial charter 15 of the concrete removal engineering change was to take 16 down concrete enough to get to a nominal one foot 17 level to remove all trades of the delamination. But 18 as you'll see going forward, we wound up taking it to 19 a significantly more extent than that in some certain 20 areas.
21 When I say the delamination is fully 22 removed, that's in our Bay 3-4, so that's elevation 23 157 up to 240 elevation. We wound up with different 24 variations in the level of our concrete removal and 25 I'll show you that in some pictures as we go forward.
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75 1 And beyond that, we wound up also doing some 2 excavations to repair some vertical cracks that we 3 found in the course of this repair.
4 And then going forward to install the 5 reinforcement, there this extensive new radial 6 reinforcement. This is another area we've had 7 extensive discussions with the staff on, on the scope 8 of that design, but as I mentioned before, we did not 9 have radial reinforcement in the original design and 10 we put an extensive amount of that new radial 11 reinforcement into places where the design called for 12 it in that plane.
13 And as you'll see in the pictures we've 14 added an extensive amount of horizontal and new 15 vertical reinforcement.
16 MEMBER ABDEL-KHALIK: Now what confidence 17 do you have that this additional detension has not 18 created another delamination 10 or 12 inches deeper 19 than the original one?
20 MR. CAHILL: As you can see here, we went 21 down to the main, middle part of the containment.
22 We've gone all the way down to the liners, so there's 23 no place left to delaminate. And those other areas on 24 the two sides of that you can see that that's about a 25 nominal 24-inch excavation of concrete. So we've got NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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76 1 pretty extensive access to it and I'll talk a little 2 bit later about some of the vertical cracks that we 3 found that we wound up excavating and refilling. It 4 gave us an opportunity to go all the way down to the 5 liner in some places.
6 We did not see any evidence of 7 delamination. We have a high degree of confidence 8 that delamination -- our design was sound and the 9 repair we went through did not propagate it any 10 further and make a new one. We did have one, I guess 11 in the repair opening, we had I guess a secondary one 12 and that was one of our reasons for driving to take 13 just all the concrete off to make sure there was no 14 doubt about that in that middle area which you can see 15 we've gone all the way down to the liner.
16 One other thing I just want to point out, 17 as you're looking at this picture, this is the back of 18 our liner right here. So this is the liner plate.
19 These are the stiffener bars that you see and those 20 are the vertical stiffener bars that are reinforcement 21 for the liner. You can see now this is the original 22 SGR opening and you can see the weld where it was cut 23 out. You can see we extensively went beyond the 24 original steam generator placement opening in the 25 extent of what we removed.
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77 1 I point out the liner back to the 2 subsequent discussions and I know this is obviously a 3 very big license renewal question is the condition of 4 your liner. One of the things that this repair 5 afforded us was extensive opportunity to get access to 6 the back side of our liner to be able to see the 7 condition of it.
8 You'll notice that up in the top levels up 9 to the ring girder, we did not remove concrete there 10 to the same level of depth because of that existing 11 reinforcement, there's extensive reinforcement of the 12 ring girder, both down on the bottom by the equipment 13 hatch. But nominally, we took down to three different 14 depths. In the middle, we call that our full 42-inch 15 depth. On those two side columns, you'll see -- we 16 call that a 24-inch depth of excavation out of our 17 original 42. And then on the sides here, where there 18 is existing reinforcement also by the ring girder, 19 we've taken it nominally to 1 foot to 15 inches, 20 again, to make sure we removed all traces of 21 delamination. But up in those locations you've got a 22 significant amount of rebar that already exists there 23 from the original design that would have made any more 24 excavation challenging.
25 Our engineering change, the one on the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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78 1 Phase 3 for the delamination removal dictated exactly 2 how we left this. It has a very precise amount of the 3 criteria for leaving in place the geometry so that 4 when we come in and pour concrete into it later, it's 5 going to be filled without any voids. There's also 6 surface roughness. We have a new to old concrete 7 interface here and there's some very precise 8 requirements and QC checks on the surface condition to 9 make sure we had a good bond between the new and old 10 concrete.
11 This is just a picture to talk about some 12 of our radial anchors. These are the actual radial 13 anchors that I mentioned. This is an outer -- this is 14 our new outer rebar mat. You can see it's outside of 15 the plane of the horizontal and vertical tendons, but 16 these radial anchors are hook-shaped bar connected to 17 this outer rebar mat with that hook or grouted in a 18 hole that's a bore about 20 inches deep so it's routed 19 in there and there's substantial radial reinforcement.
20 And they're extensive, as you can see the picture.
21 They're quite closely spaced.
22 This is as we went through the phase of 23 reinforcement installation, this is putting the inner 24 layer of rebar mat. This is an area I mentioned in 25 one of the pictures. We did not have any rebar, so as NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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79 1 you mentioned before, there's a significant change to 2 this as far as an outer rebar in there. So there's 3 inner rebar mat as well as vertical cages that have 4 been put inside the hoop and vertical plane, vertical 5 tendon plane, excuse me.
6 CHAIRMAN SIEBER: And the vertical tendons 7 you can see in this particular --
8 MR. CAHILL: Yes. This is our final 9 picture. You can see some of the extensive amount of 10 reinforcement that's been put in there. We've got 11 about 52 tons of steel that has been put in this 12 repair effort. You can see these are some of the 13 vertical cages as well as there's an outer mat outside 14 of that, so it's a much more congested, more highly 15 reinforced. And that again was dictated by the design 16 that was developed for the starting point where we 17 left containment about doing the detensioning.
18 This next slide is a very important one to 19 us. As you noted, this was a unique repair effort, 20 not something that any other utilities have had much 21 experience with. So one of the fundamental things 22 that we put in place was a mock up. This is actually 23 our mock-up wall that was built outside of our fence.
24 This is a full-scale mock up and it basically 25 mimicked every depth of excavation I mentioned before.
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80 1 It's mimicked every reinforcement feature, every 2 anchorage technique and we actually placed concrete 3 fully in this model, put forms up there, fully placed 4 the concrete, and then cut it open at the end to make 5 sure that we validated that we were getting the 6 results we expected.
7 I think that's a pretty unique thing 8 showing the amount of rigor we put in to making sure 9 we knew what we were leaving behind with this as far 10 as the construction and design techniques. This was a 11 challenging physical effort and we wanted to make sure 12 we knew we had it right. That mock up is 13 something that was very time consuming, but I think 14 very important for us so going forward to have 15 confidence in our repair.
16 So going forward at replacing the 17 concrete, I'm not going to go into a lot of detail on 18 that, but we wound up placing concrete in five-foot 19 lifts. That is a small amount than the original 20 construction was done. It was done in ten-foot lifts.
21 A lot of that was dictated by the lessons that we 22 learned on our mock up before we actually went up on 23 the wall. We actually had an on-site batch plant to 24 develop the engineering mix that we had designed. We 25 used the same mix that was planned for the steam NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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81 1 generator replacement opening which is optimized for 2 our existing concrete already in the aggregate we 3 have.
4 Again, the next phase of that was the 5 retensioning sequence. That's in progress right now.
6 We have to go retension those 155 and 64 vertical 7 tendons. We have approximately touched 30 of those 8 thus far.
9 CHAIRMAN SIEBER: Okay. I'd like to just 10 stop just for a second. We have a question from a 11 person on the bridge line. In order to do that we've 12 got to rearrange the telephone system a little bit.
13 After we do that, we'll see what the question is.
14 There are enough people on the bridge line 15 so you'll have to drop somebody off in order to get 16 enough volume and low enough impedance to get the 17 question and then we'll connect it all together again.
18 I noticed the one picture, the back side 19 of the containment liner, the liner doesn't look 20 particularly smooth in that picture. Is that just an 21 artifact of construction or --
22 MR. CAHILL: Yes.
23 CHAIRMAN SIEBER: Or an artifact from 24 removal of all the concrete?
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82 1 relief from moving the concrete and the tendons and we 2 did see the liner move, but we had the same concern 3 and looked into that and looked at our original --
4 CHAIRMAN SIEBER: Now has it changed 5 during the life of the plant for -- did all the change 6 to the liner surface occur during this deconstruction 7 repair and reconstruction phase.
8 MR. CAHILL: You mean change in the 9 surface, you mean just change in the general --
10 CHAIRMAN SIEBER: It doesn't look smooth.
11 All the pictures I've seen it does not look very 12 smooth compared to other containment liners that I've 13 seen.
14 MR. CAHILL: I don't think you've ever had 15 the chance to see this much of an extent to the back 16 of the --
17 CHAIRMAN SIEBER: Nor have I ever had the 18 opportunity to see much of the back of anybody's 19 liner.
20 MR. CAHILL: But there was some stress 21 relief from the repair effort. We saw that when we 22 took the steam generator replacement opening, just the 23 detensioning of the original scope of tendons caused 24 some stress relief once we took the original liner out 25 for the SGR Opening and we just saw some of that.
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83 1 CHAIRMAN SIEBER: Are we set? Go ahead.
2 We'll just take a few seconds to see if we can 3 accommodate this question.
4 MR. BARTON: While we're taking this 5 break, the question on -- you've had some areas of 6 your liner where you've got bulges. Where this liner 7 is exposed in this one photograph, on the inside of 8 that liner in that area, are any of the bulges that 9 you found in that area?
10 MR. CAHILL: Our bulges are dispersed and 11 I'll be talking about that later, but they're 12 dispersed pretty much all in different portions of 13 containment. So yes, we had the opportunity of being 14 on the back side of the liner where we could see them, 15 particularly when you had up at the upper levels where 16 you had to cut and you had the concrete still up 17 against the portions of the liner. You could see 18 actually, you could get behind them and see that there 19 was a gap in some places between the liner and the 20 concrete. So this gave us a good opportunity to --
21 MR. BARTON: Were you able to find 22 anything in the concrete that would account for 23 closing the bulge?
24 MR. CAHILL: Absolutely not. Obviously, 25 we had that same concern and that's why we went after NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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84 1 the bulges as aggressively as we did.
2 MR. BARTON: Seen at other plants whether 3 that bulge is -- that a bulge -- all kinds of debris 4 causing a bulge.
5 MR. CAHILL: I've got a couple of slides 6 we're --
7 MR. BARTON: I note that later on.
8 MR. CAHILL: I can conclusively say no, we 9 have found no corrosion or debris mechanism whatsoever 10 that has been behind any of these bulges that accounts 11 for those. And we went up to a pretty extensive 12 effort to be able to account for those bulges to 13 understand why they are there, what the cause was.
14 It's not any mechanism such as that.
15 MEMBER SHACK: You did your structural 16 analysis to verify your design basis behavior. Did 17 you carry that to above internal pressure ratings 18 above design basis so your ultimate strength was 19 affected?
20 MR. CAHILL: Yes, we've done different 21 looks at the analysis and we've got the factored loads 22 that we have --
23 COURT REPORTER: Could you repeat that?
24 MR. CAHILL: I said we've had very 25 detailed interactions with the staff and the special NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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85 1 inspection team on the nature of that design. That's 2 been a very key issue that they've been pursuing.
3 CHAIRMAN SIEBER: Is there anyone on the 4 line?
5 MR. HOLIAN: Lou Lake, are you still on 6 with Mark Franke? We had an issue earlier whether the 7 region was on the line and they just could hear us and 8 they couldn't speak. So Kent will check on the people 9 that have come down. There wasn't somebody who was 10 asking a question. It was NRC staff trying to tie in.
11 So at our break we can see, but we can continue.
12 MR. CAHILL: All right, I mentioned 13 retensioning that is in progress now. We are doing a 14 very detailed sequence that's very inefficient, but 15 it's using partial tensioning. We're actually -- each 16 tendon we're going to touch twice. We're going to 17 tension it half way, leave it, go on to some other 18 tendons and then come back at a later point in the 19 overall sequence and fully tension that last tendon.
20 Also of note as part of our overall 21 design, the 80 remaining vertical tendons, these were 22 not part of the 64 that I mentioned that were 23 detensioned and removed. Those 80 other ones will 24 also be reset to the original construction. So 25 they'll be consistent with the 64 that we actually NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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86 1 removed. So they will all be detensioned to the same 2 original construction value, essentially reset.
3 And the last part of the repair and I'll 4 be talking about this later in some subsequent slides 5 is we plan to as an owner-elected structural integrity 6 test, we plan to perform followed by an integrated 7 leak rate test.
8 A little bit to discuss on the impacts on 9 the containment liner. Our exposed containment liner 10 reinforcement were very thoroughly examined in 11 accordance with the Section XI Code requirements. And 12 we did note and that's why we put the picture up 13 there, that we've found minor indications. There's 14 nicks and gouges, some welding arc strikes at the 15 liner rebar. Each of those areas was evaluated in 16 detail and repaired to restore the materials and 17 surface conditions to meet the design requirements.
18 We did find a lot of those indications, 19 some of them were from original construction. None of 20 them were significant, but all those repaired. Some 21 were created by actual repair effort, just the 22 extensive amount of work as you can imagine removing 23 concrete, you've got to be very careful not to damage 24 the liner. And our construction team did a good job 25 at that, but we did find some things that we had to go NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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87 1 repair. But I can tell you with confidence we've gone 2 over this inch by inch and our liner was in pristine 3 condition before we placed concrete against it.
4 CHAIRMAN SIEBER: Did you find any due to 5 corrosion or other aging effects?
6 MR. CAHILL: No, we did not and that's one 7 of the things with the extensive amount of access we 8 had to the back side of the liner, I think 9 unprecedented compared to any other utility, we did 10 not see anything along those lines.
11 CHAIRMAN SIEBER: Okay.
12 MR. CAHILL: I can say with confidence 13 that we've restored the liner in much better shape 14 than it was found in this area.
15 Another thing to note, I mentioned this 16 before, is some impacts on the liner. We did note 17 additional concrete cracking. As we went through the 18 repair effort, we did find some vertical cracks. As I 19 mentioned originally, our design was not to take this 20 all the way down to the liner. We did see vertical 21 cracks in Bay 3-4 as well as some horizontal ones 22 above and below the opening. They were caused by 23 residual stresses which after the fact we could very 24 clearly understand why they were there, but we elected 25 -- and that's one of the reasons that drove us to the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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88 1 decision in this area to take it all the way down to 2 the liner.
3 These are some of the vertical cracks that 4 I was just pointing out. They're actually highlighted 5 in yellow. We had done that as part of mapping of 6 those. And they are exacerbated by the actual 7 hydroexcavation tends to wallow these out. They are 8 tight, fairly hairline cracks, but hydroexcavation 9 makes them look bigger. But each of those cracks were 10 excavated and they were either completely refilled or 11 restored to a geometry that when we did final 12 placement that we validated with our mock up and we'd 13 get it completely filled in.
14 So these cracks as they look now, they 15 were completely repaired except there was some 16 horizontal cracks and exist in these places over here 17 that we just completely remove by taking all that 18 remaining concrete out. There are some cracks that --
19 some hairline cracks that are in the areas edged by 20 the buttresses that we wound up leaving in place 21 because of existing reinforcement from a design 22 perspective was already there to address the potential 23 for concrete cracking.
24 Again, this is an issue that we've had 25 extensive interactions with the staff on, on the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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89 1 nature of the cracking we found and what we've done on 2 each one. But just this effort to go repair these 3 vertical cracks that I just highlighted with the laser 4 pointer, that was about a month and a half repair 5 effort to make sure that we did the right thing with 6 those --
7 MEMBER ABDEL-KHALIK: Now these vertical 8 cracks are not exactly vertical, but yet the spacing 9 seems to be roughly uniform between the cracks. Is 10 there a mechanism that you have explored that would 11 allow you to predict the spacing of these vertical 12 cracks?
13 MR. CAHILL: I mean they generally run in 14 vertical tendon alignments, but they're really driven 15 by just the residual stresses as we detension 16 containment. Basically, if you look at this we took 17 typical tendons that were on top of this, took away 18 that, and then took away all the hoop tendons and 19 basically kind of opened up this bay. That's what 20 created the vertical cracking. So we did go back and 21 validate with analysis the cause of them and it was 22 somewhat expected. We knew going into this repair 23 effort we ran the risk of that.
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90 1 remove it and start over. But would be very 2 problematic because then we would have had to go to 3 significantly more scope of detensioning because that 4 concrete that's left there that you see was actually 5 still structurally holding the weight of the ring 6 girder as well as the ring. The only vertical tendons 7 that were detensioned were in this bay and the one 8 exactly opposite on the back side, Bay 6-1. The 9 vertical tendons in the other four bays were still 10 tensioned, so there's a significant amount of force 11 still existing in this containment.
12 CHAIRMAN SIEBER: Now these are all 13 vertical cracks.
14 MR. CAHILL: Yes.
15 CHAIRMAN SIEBER: And I would think that 16 vertical cracks were like tension cracks. If you 17 detension horizontal tendons, would that not cause the 18 stresses to give you vertical cracks around the entire 19 circumference of the containment?
20 MR. CAHILL: Yes, we did see some of those 21 that were not just for releasing the stress, but just 22 due to the release of the creep and the differential 23 between the steel conduits and the steel that was left 24 and in the concrete. The concrete had crept over 30 25 years of being in full tensioned containment and when NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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91 1 we detension those tendons in those elevations where 2 we removed those tendons going around, we did see some 3 vertical cracks in areas outside of these areas and 4 hairline cracks.
5 CHAIRMAN SIEBER: Obviously, I could see 6 the terminus of the horizontal tendons and the 7 vertical ones actually, in the areas where you're all 8 the way down to the liner, so that's -- all that 9 tension has been relieved and created a whole new 10 stress set up in the remainder of the containment 11 shelf and I would think there would be cracks 12 everywhere.
13 Do you know whether there are or not and 14 if you know whether there are or not, does it make a 15 difference from the standpoint of structural 16 integrity?
17 MR. CAHILL: We've looked and we've done 18 extensive mapping of all the other bays and we do see 19 in a certain elevation band which correlates with 20 where we've done the retensioning, we see on surface 21 indication we seen some evidence of hairline cracks.
22 They're all less than seven mils. Most of them are 23 pretty much very tightly clustered around five mil 24 range. And our cause determination determined that it 25 was based on the detensioning effort.
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92 1 We have looked at those and incorporated 2 those in our design. We are expecting them and have 3 actually seen and heard those closing as we have gone 4 through the retensioning right now. So structurally 5 we have assumed that they all go through-wall, but --
6 CHAIRMAN SIEBER: I would think so, but I 7 don't know if you have any other choice as far as the 8 integrity of -- the gross integrity of the vessel 9 itself. You're relying totally on the tendons, not on 10 rebar, not on concrete, right?
11 MR. CAHILL: Our design assumes that we 12 have contact between all those places where there 13 could potentially be a vertical crack and we have 14 monitoring in place which I'll talk about later to 15 verify that they have closed, as we expected, and we 16 have that context, so that you can transfer sheer 17 across that plane.
18 CHAIRMAN SIEBER: Have they analyzed 19 containment, those assumptions that the only members 20 to carry the load are the horizontal and vertical 21 tendons, horizontal meaning the hoops?
22 MR. CAHILL: Yes, we've not credited in 23 our design coming out of this, we're not taking any 24 credit for any tensive capacity of the concrete in 25 those other bays. So that's -- the answer to your NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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93 1 question is yes.
2 CHAIRMAN SIEBER: And are you crediting 3 any rebar?
4 MR. CAHILL: Are we crediting any rebar?
5 CHAIRMAN SIEBER: Yes.
6 MR. CAHILL: Not in those other bays 7 because we don't really have any structural rebar 8 other than around the periphery.
9 CHAIRMAN SIEBER: Well, it looked like you 10 had some rebar in the repair.
11 MR. CAHILL: The repair, yes.
12 CHAIRMAN SIEBER: That to me looks like a 13 different design than what I recall the regular 14 structural design of this type of containment.
15 MR. CAHILL: Yes.
16 CHAIRMAN SIEBER: So you've got probably a 17 hard spot in a containment that's basically more 18 flexible.
19 MR. CAHILL: And we had to do extensive 20 analysis to make sure that that was accounted for.
21 CHAIRMAN SIEBER: Yes, the analysis for 22 that because it had discontinuities would not be 23 simple.
24 MR. CAHILL: Yes. And the repair efforts 25 is because you start with that discontinuity --
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94 1 CHAIRMAN SIEBER: I presume the staff has 2 reviewed the analysis that we're discussing right now?
3 MR. CAHILL: I can say yes, because I know 4 we had a lot of interactions with the civil staff.
5 CHAIRMAN SIEBER: We'll ask them when it's 6 their turn.
7 MR. CAHILL: Next slide, Jeff. Just 8 overall, the liner is very important to us. The liner 9 is our fission product barrier and the ultimate design 10 of this pre-stressed containment is to make sure we 11 protect that liner.
12 Now we've looked at all design impacts on 13 the liner due to the repairs and evaluated those in 14 detail which I mentioned before includes normal 15 calculations and analysis that have been reviewed in 16 detail by the staff. The results of these are 17 validated that there is no impact on the current 18 design basis of the liner. All our original strain 19 limits continue to be maintained.
20 Next one.
21 CHAIRMAN SIEBER: Looks like we're about 22 halfway through.
23 MR. CAHILL: Right now I'm going to talk 24 about the liner bulges. These liner bulges are not 25 new. We've seen these before. They're something we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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95 1 extensively investigated over the course of this 2 extended outage because we had the opportunity and saw 3 them and we wanted to make sure. But we did not see 4 any correlation between the delamination event and 5 these liner bulges. We've seen these bulges. They 6 occur between the vertical stiffeners. You saw those 7 vertical stiffeners in that picture before. They're 8 18 inches apart. And we had the opportunity to go 9 look at those in detail.
10 We've always monitored these bulges in the 11 past and evaluated them per our formal IWE Program, 12 but the evaluations of those has always been 13 qualitative. So as part of this effort we went 14 through a very extensive extended condition effort to 15 understand the scope of these bulges, where they were 16 and we went through basically two phases of that. One 17 is in upper elevations we performed detailed laser 18 scans above our 160 elevation which is our refuel 19 floor. And that's a significant force in our 20 containment, well over half that we can actually use 21 laser scanning to get very detailed measurements.
22 We also at lower elevations where you've 23 got interferences, you can't reliably get the 24 comprehensive laser scanning. We did the detailed 25 visuals as well as manual measurements of the existing NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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96 1 bulges.
2 We did mention before you were concerned 3 about what we found on some of those. In our extended 4 condition we found the bulges are random and normally 5 distributed in location of size, but we wound up doing 6 a UT measurement on our most limiting bulges, the 7 largest as well as some of the representative samples.
8 We have done others in previous outages and we've 9 never seen any loss of wall thicknesses on any of 10 those bulges, but the ones that we did during this 11 outage which were our largest ones, we did not see any 12 indication of any mechanism, no corrosion mechanism, 13 no loss of wall thickness, anything that would cause, 14 I guess, a concern for what other, I guess, liners 15 have been the source of OE in the industry.
16 MEMBER ABDEL-KHALIK: What is the cause of 17 the bulges themselves?
18 MR. CAHILL: I'll get into that if you 19 just give me a minute, in the next slide. We took 20 hundreds of UT readings on the liner, the portion that 21 we had exposed. That was done for the steam generator 22 repair effort and it was also confirmed that we don't 23 have any mechanism that's causing us to lose any 24 thickness on the liner. So we confirmed, I think, 25 conclusively for the bulges that there's no wall NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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97 1 thinning or corrosion mechanism that's associated with 2 those.
3 This next picture, this is a typical 4 output we get from a laser scanning. Laser scanning 5 uses an auto-CAD feature to allow dimensioning of the 6 bulges in 3-D. So we can measure any distances 7 between of those imaged items. And these are typical 8 of the bulges we have.
9 You can see there's actually measurements 10 placed up there on most of them. Most of them are 11 nominally, when we see them, are about a half inch at 12 their peak in between the stiffeners and that's the 13 measure that we take because that's the largest one.
14 And you can see that they don't, I guess, 15 travel beyond stiffeners and they really can't because 16 the stiffeners embed in the concrete, but they also 17 don't go beyond the weld, this weld line which is just 18 the different plates of the liners that was 19 constructed. That nominally arrests any propagation 20 of those.
21 Next is just a picture looking up. This 22 is our containment dome. So you can see with the 23 large elevations laser scanning is a very valuable 24 technique to be able to comprehensive go out and map 25 these. And it is a very precise technique.
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98 1 Truthfully, it's been my first exposure to it in a lot 2 of detail. I'm really impressed with the vendor we're 3 using and the ability we have to get engineering data 4 out of it.
5 After we got that extended condition 6 behind us, we realized that we needed to probably do 7 some more robust engineering effort to understand what 8 the technical basis for these being acceptable was.
9 Like I said, they had been evaluated before by a 10 qualified professional engineer, a civil engineer, as 11 part of our program is having no impact, but we 12 decided to do something more comprehensive because we 13 realized the only true acceptance criteria we had was 14 kind of an existing thumb rule of .72 inches as far as 15 the bulge. That didn't really have much technical 16 basis behind it. Other utilities have been using it, 17 but when we wound up pulling the string to understand 18 more about that, we did not really find anything 19 behind that beyond an original construction tolerance.
20 So we actually chartered a finite element 21 analysis. We used structural integrity for this, as 22 well as doing an apparent cause investigation in the 23 course of going through investigating this data that 24 we had gotten from our scanning inspections to 25 understand what could have caused it. So that effort NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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99 1 that they did include the bulge growth that could have 2 occurred due to past load history as well as permanent 3 loads on containment.
4 The result that we got from that effort 5 determined that a maximum acceptance criteria for 6 bulge is 1.82 inches. That limiting component that 7 dictates that is the stitch welds on the stiffeners.
8 They are designed to release so that you don't have 9 those welds tearing apart the liner if you had a 10 design basis event and you had movement, but as part 11 of our design basis, we cannot allow that to be 12 something that the bulges could allow to happen. So 13 that was the most limiting component in that 14 evaluation.
15 A very, I guess, noteworthy thing coming 16 out of that investigation apparent cause though was 17 the finite element analysis was unable to identify any 18 loading condition that could create and result in a 19 bulge. You always had to have some initial, I guess, 20 anomaly just start. If the liner was in the design 21 radius for the initial curvature of construction, 22 backed by concrete, the bulges could not reliably be 23 created. So only if there was existing, I guess, 24 inward deformation could that be created. So most of 25 the notable bulges we had, the details -- you had to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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100 1 have probably something greater than a half inch 2 deviation from initial construction requirements in 3 order to basically get something that could propagate 4 over the design load, I'm sorry, over the history in 5 the design loads of containment to get to the existing 6 condition we saw now.
7 We've accepted this assessment and final 8 element analysis. It's a formal part of our design 9 basis right now. We've accepted it as a formal 10 calculation and incorporated into our design basis as 11 an engineering change.
12 Also, moving forward, this extended 13 condition is something we're going to be keeping an 14 eye on for a while.
15 MR. BARTON: When you do the SIT it will 16 all go away.
17 MR. CAHILL: No, actually, that's a 18 question -- I guess everybody expected that would be 19 the case, but we don't expect to see much change in 20 these things from the SIT. Everybody's gut reaction 21 was oh yeah, it will just flatten out. They will not 22 based on those pressures. That's something we had 23 structural integrity to look at in than we do the 24 model.
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101 1 observed from Day 1 or did they become more pronounced 2 after the event you referred to where vacuum was 3 created in the containment?
4 MR. CAHILL: And looking around the 5 industry, other similar containments, I've seen 6 examples of these. We know that they've been around.
7 We have documented records of them in our program in 8 various discrete locations from before that even. So 9 they're not anything that is, I guess, a new 10 phenomenon.
11 CHAIRMAN SIEBER: But these are unique to 12 tension containments, right?
13 MR. CAHILL: That I do not know. I --
14 CHAIRMAN SIEBER: Where they're uniformly 15 vertical?
16 MR. BARTON: I don't remember. I don't 17 remember the other bulges, whether they were this type 18 of containment or not.
19 CHAIRMAN SIEBER: Sub-atmospherics have 20 bulges in different places because of pull away from 21 the produced pressures.
22 MR. CAHILL: That's one of the things when 23 we did the analysis was look at obviously the effects 24 of being in tension containment for 30 years, you're 25 going to have some creep and that does account for NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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102 1 some of the bulge growth.
2 CHAIRMAN SIEBER: I'm sort of guessing, 3 but I'm curious as to what the reason is because it 4 tells you, once you know the mechanism, you're better 5 able to make an analysis as to where it's going to go.
6 MR. CAHILL: The only mechanism we could 7 find that there had to be some deviation from the 8 usual curvature to start. There was no design or any 9 event or anything like that we could find that would 10 cause them to just --
11 CHAIRMAN SIEBER: How thick is the liner?
12 MR. CAHILL: Three eighths of an inch.
13 CHAIRMAN SIEBER: Pretty stiff?
14 MR. CAHILL: Yes.
15 CHAIRMAN SIEBER: Okay.
16 MR. CAHILL: This extended condition is 17 documented in our IWE Program and we'll be tracking 18 the most limiting bulges going forward. We'll do 19 manual bulge measurements and as we continue to track 20 make sure that we understand the response of those.
21 I guess something notable, the acceptance 22 criteria is important to us because it gives us some 23 allowable margin. As you can see up there the one 24 most limiting bulge we have is at a 1.33 measurements.
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103 1 an inch. Most, like I mentioned before, nominally 2 that we see are much smaller dimensions, so we're very 3 closely going to monitor those four ones because they 4 are most limiting conditions.
5 But in summary, all the bulges that we 6 have are within our acceptance criteria and we're 7 going to continue to monitor those with our program 8 with some augmented inspections which I'll discuss 9 later going forward. We did just to note from that, 10 the reason it says manual measurement up there on that 11 dome bowl is we originally had a laser scan 12 measurement. We went up and did a manual measurement 13 just because it's a slightly higher level position 14 than the laser scan and that's why we went up to do 15 that.
16 Any other questions on the bulges?
17 This goes into my discussion on close 18 repair testing. This is just a summary slide just 19 talking about what I mentioned before. We plan to do 20 an integrated leak rate test. This is required for, I 21 guess, two main drivers out of ASME Section XI.
22 Obviously, we had always planned on doing one because 23 we removed and replaced the liner for the original 24 steam generator placement opening, so we planned to do 25 an integrated leak rate test before the delamination NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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104 1 for that reason. But also the required pressure test 2 per the code for the repaired concrete, the ILRT will 3 be credited for that.
4 As I mentioned before, we also plan to do 5 an elective Structural Integrity Test. Structural 6 Integrity Test is normally something that's only done 7 once in the life of a plant as part of construction.
8 As we are characterizing this as repair, a Structural 9 Integrity Test is not required, but we do intend to do 10 one. So we're doing it electively, although we will 11 do it fully in accordance with ASME Section III, the 12 subsection which drives this which is CC 6000. We 13 elected to do that just to make sure that there was no 14 question that we were doing it to some different 15 standard. So we're doing it per the original 16 requirements. And that will be done at 63 pounds 17 which is 1.15 of our peak design pressure.
18 The SIT will be done first, followed by 19 the IRLT just because you need to have the IRLT second 20 to verify leakage of containment before you can 21 declare it operable.
22 This slide is going to be busy going 23 through. This is the things that we're doing for pre-24 start up. All these things that I'm going to go 25 through here are all driven and formally contained in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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105 1 our formal engineering change or EC that I mentioned 2 before. The first section is just things that are 3 driven by Section XI as part of repair/replacement.
4 We're going to be detailed VT1 exams of 5 the new concrete surfaces. That includes all the new 6 concrete in Bay 3-4, as well as all the other repairs, 7 so every time we refill the core bore, any place we 8 put a hoist or a scaffolding anchor bolt, those need 9 to be done as far asSection XI requirements. And 10 those inspections will be done prior to, during, and 11 after the ILRT.
12 We'll also be doing detailed visual exams 13 of the liner, the opening repaired areas. So the 14 steam generator replacement original cut, the weld 15 repairs we've done and any other repairs as well as on 16 the inside containment is part of the structural 17 integrity test. We are mounting taut wire straining 18 gauge -- strain gauges to get the measurements we need 19 for the SIT, so that also has an impact on the liner 20 and those need to be inspected. And those inspections 21 will be done prior to and after the ILRT.
22 We'll also be doing detailed visual exams 23 of VT1s of the tendons, the tendon anchorage areas for 24 any manipulated tendons. We'll be doing that after 25 retensioning and then as mentioned, the Section XI NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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106 1 drives the ILRT as part of a required test.
2 MR. BARTON: I don't see anything on your 3 bullets there, but there was an issue with leaching on 4 the walls in the tendon access gallery. And you guys 5 were going to go in and look at that and do some core 6 bores and try to figure out what the cause of the 7 leaking. Did you do that?
8 MR. CAHILL: Actually, we had the 9 opportunity. We decided to go after some groundwater 10 leakage in our decay heat vault which is the lowest 11 level in our Aux. Building, so in conjunction with 12 that we went after the tendon gallery and so forth.
13 We did do a pretty comprehensive effort. We actually 14 did some repairs for the decay heat vault, but that 15 was -- we might have seen a gap in the construction 16 joint that accounted for a lot of that groundwater 17 leakage.
18 So we confirmed that we don't have any --
19 there's basically no iron deposits in any of the water 20 leakage and the core bores we did, we actually got a 21 chance to get one of our one-time inspections done, 22 inspecting that rebar both in the decay heat vault and 23 tendon gallery and found no damage mechanism 24 whatsoever going on. The rebar was actually in 25 pristine condition.
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107 1 All the sampling we did on the effluent 2 groundwater that was coming in, I mean there's a lot 3 of different details, chloride tests and things like 4 that. They all came completely favorable. So those 5 are a good thing to get behind us, not something we 6 originally planned to do until we got close to the 7 period of extended operations, but we do have that 8 confirmed. But we're going to be doing some more 9 efforts on that just to mitigate that groundwater 10 leakage that we're seeing.
11 The next section down, these are some of 12 the requirements that I guess we're doing the SIT per 13 Section III, so that requires us per CC 6000. We'll 14 be doing visual exams in the accessible portions of 15 the containment. So that includes concrete and the 16 liner. That has to be done prior to and after the 17 SIT.
18 One of the main things you do during SIT 19 though is you do detailed crack mapping. We'll be 20 doing that prior to, during, and after the SIT. By 21 that, I mean you're required to -- these three areas 22 of 40 square feet to actually map out and do detailed 23 crack mapping during those periods. We've selected 24 five areas including one on the dome. All those areas 25 for us are greater than 60 square feet, so we've gone NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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108 1 a little above and beyond what the crack mapping 2 requirements is just because we had different areas of 3 interest and we wanted to make sure we were doing a 4 detailed look at that.
5 CHAIRMAN SIEBER: That's all on the 6 outside of containment?
7 MR. CAHILL: That's all on the outside of 8 containment, yes.
9 And also just as part of an SIT, we do 10 displacements and as I mentioned, we have taut wires 11 that will be running all through the inside of 12 containment between the liner and our internal 13 structures like our D Ring up to the dome and so forth 14 as all monitoring pressures and temperatures. Those 15 will be monitored prior to, throughout and after the 16 SIT to help dictate the success of that SIT.
17 This next slide is also things that we're 18 doing pre-start up. And this is stuff that is 19 contained formally in our engineering changes, but 20 these are all augmented, owner-elected activities. So 21 we'll be doing laser scanning of our liner bulges 22 going forward. We'll be doing that prior to and after 23 the tendon retensioning. As we finish our tendon 24 retensioning, we'll do that. We'll also do it again 25 after the pressure tests, just to verify that they did NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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109 1 not change as we discussed earlier.
2 We'll be doing liner bulge measurements of 3 our most limiting ones prior to and after the tendon 4 retensioning, after the pressure tests. We're doing 5 vertical crack width measurements. These are the 6 cracks that you mentioned before outside Bay 3-4 that 7 we've seen. We've already done those prior to 8 retensioning. We'll be doing those after retensioning 9 as well as after the pressure tests.
10 We'll be doing a general VT3 visual exam 11 outside of all concrete containment surfaces, outside 12 of the areas affected by the containment repair.
13 That's normally something that we do one time period, 14 but this gives us a baseline going forward, just so in 15 future outages and inspections, we understood exactly 16 where we left it with this outage.
17 We also have over 80 embedded stream 18 gauges throughout containment, primarily in Bay 3-4, 19 but several in other bays. We'll be monitoring those 20 prior to, throughout, and after retensioning through 21 the completion of the pressure tests as a source of 22 data.
23 Our laser scan data will also be giving us 24 storing displacements. We're doing that as efforts 25 storing our tendon retension. Another method of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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110 1 evaluation we have is acoustic sensors. We have 2 acoustic sensors mounted all around exterior 3 containment. We'll be monitoring those during tendon 4 retensioning. Those listed and are calibrated for 5 concrete cracking, so if we were to create another 6 delamination or any potential incipient cracking that 7 could cause a delamination, these acoustic monitors 8 are optimized in locations where we would see the peak 9 stresses to be listening for that and to give us an 10 indication that we might need to do something 11 different.
12 And then lastly, we plan on doing a lot of 13 time after the retensioning to go do impulse response 14 testing, IR scans of the containment concrete. We'll 15 be doing that in targeted high-stress areas so it 16 won't be a comprehensive, but the areas if there was 17 any problem based on our analysis that we have used to 18 design a separate going forward. We're going to be 19 doing IR scans there to make sure nothing happened.
20 And these last two bullets, these are 21 things that are driven out of Corrective Action 22 Program. Coming out of the root cause, we had two 23 things that we needed to do. They're not quite 24 finalized yet, but the first one is for areas outside 25 Bay 3-4. We will continue to have a scope of impulse NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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111 1 response mapping in that area going forward both the 2 test and as well as future outages, we'll go take a 3 look at that to make sure nothing else has happened.
4 And then also inside Bay 3-4 with the 5 amount of reinforcement you saw there, IR scanning is 6 not a very valid technique to use just with amount of 7 reinforcement. You can't get a valid mobility number 8 with all those steel interferences. So inside Bay 3-4 9 we're going to be using the extensive amount of 10 existing strain gauges that we've installed there and 11 come up with a monitoring program to credit and keep 12 an eye to make sure that those interfaces between the 13 new and old concrete are behaving as expected.
14 This next slide moves into things we plan 15 on doing after start up, so post-start up. Again, 16 first section is dictated in our engineering change, 17 the Section XI requirements.
18 MEMBER ABDEL-KHALIK: If there is new 19 delamination in Bay 3-4, after this is all repaired, 20 how would you detect that?
21 MR. CAHILL: We would detect that with the 22 strain gauges. We've had extensive interactions with 23 the staff on how we would be able to detect any of 24 that. The delamination with the extensive amount of 25 reinforcement as now in Bay 3-4 is highly unlikely.
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112 1 We have strain gauges both in the radial and different 2 directions that would detect any movement that would 3 give you delamination and they are strategically 4 dispersed throughout that opening. So that would be 5 our mechanism for monitoring and assuring ourselves 6 that we have not had anything. And if we had a 7 delamination, like I mentioned before, the acoustic 8 monitors would be able to pick it up and that's how we 9 would give ourselves that confirmation.
10 The amount of reinforcement we'd put in 11 there, we can't use really IR reliably in Bay 3-4 any 12 more so that's why we came up with other mechanisms to 13 assure ourselves that there is no delamination.
14 So going post-start up, we'll be doing a 15 BT3 inspection of all the surfaces affected by the 16 repair replacement activities. Also, the augmented 17 tendon exams and testing of those that were affected 18 by the repair replacement, we'll be doing those after 19 we have a one-year requirement to do those following, 20 so we'll be doing some tendon testing one year out for 21 start up. That four percent scope is above our normal 22 five-year requirement, so we'll have two populations 23 that overlap in our next refueling outage, the four 24 percent augmented and then our normal five percent, 25 two percent that Rick mentioned before that we would NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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113 1 normally be doing.
2 And then other owner augmented type of 3 inspections, as I mentioned before the vertical 4 cracks. We plan to go look at those vertical cracks 5 one year after in conjunction with the other 6 inspections. We'll be looking at that to see if those 7 continue to stay closed as we expected they would.
8 We'll also be doing liner bulge measurements of those 9 most limiting locations. Also, we have that plan for 10 doing it in the next three refuels after completion of 11 this replacement.
12 And these are very similar to what I 13 mentioned before, these last two are Corrective Action 14 Program driven actions to monitor the concrete in Bay 15 3-4. We have the strain gauges as well as come up 16 with a program for periodically monitoring outside Bay 17 3-4, using an NDE technique such as impulse response.
18 This next slide is just talking about some 19 things that -- a discussion topic driven by NEI 94-01.
20 This is the industry guideline for implementing 21 performance-based option of 10 CFR 50, Annex J 22 testing. That guidance section 9.2.3, the extended 23 test interval states that you can extend your Type A 24 testing to a frequency of at least once per ten years 25 if you have an acceptable performance history.
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114 1 Crystal River previously established an acceptable 2 performance history of our integrated leak rate test 3 and already extended that ten-year interval. So that 4 fostered some discussion out of 9.2.4 which is the 5 containment repairs and modifications. It mentions 6 that repairs and modifications affect leakage 7 integrity and it will require a leak rate test, a Type 8 A test or local leakage rate testing prior to return 9 of the containment to operation.
10 So as I mentioned before, we are planning 11 to do an integrated leak rate test, but based on our 12 work being classified as repair, we do not intend on 13 changing our performance-based interval. We expect to 14 have a valid performance history with our integrated 15 leak rate test due to the quality of our liner. So we 16 are maintaining our current interval and that is our 17 plan going forward, assuming a successful performance 18 of the test that I just laid out.
19 CHAIRMAN SIEBER: Because that's what the 20 words say. There's a tremendous amount of 21 modification being done and I think I'll let the staff 22 decide on what's adequate or not. I could go either 23 way on it.
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115 1 concept is there, because these things have been built 2 before, even though your repairs are a little on the 3 unique side and a single test ought to prove 4 construction integrity, but I still think there's some 5 question considering the extensiveness of the repairs 6 as to whether you've got to go to the review team a 7 little more. I'll let the staff decide.
8 MR. CAHILL: This next slide is just to 9 specifically respond to items in the open items for 10 license renewal. We were specifically requested on 11 how our experience with this overall containment 12 repair is going to be incorporated in our programs and 13 also whether plant-specific program is necessary to 14 manage the aging.
15 I mentioned before that the changes to our 16 program were the ones driven by the ASME Section XI 17 repair and replacement, so we talked about those 18 changes before that we are going to be doing and we'll 19 also be doing several augmented owner-elected 20 inspections of things going forward which were from 21 those previous slides I selected. Most notably, the 22 additional ones that we're talking about are the 23 vertical crack inspections that we'll look at at the 24 one-year point and we'll reassess continuing that at 25 that one-year point depending on the results and the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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116 1 liner bulges.
2 So in overall summary, we're not -- those 3 are the things that were used by, driven by the repair 4 replacement code as well as the augmented ones that 5 we've done to change our program, but we did not 6 conclude coming out of this repair effort that we 7 needed to develop a plant-specific containment aging 8 program. Most of the issues we saw we did not see an 9 aging mechanism associated with them and that was the 10 basis for our conclusion.
11 CHAIRMAN SIEBER: So the real basis for 12 not having a plant-specific containment aging program 13 is that this was a one-time event under unique 14 circumstances or caused by an aging mechanism?
15 MR. CAHILL: Yes. And we've done several 16 things within our existing programs to augment those 17 as well as utilize the aspects of the existing 18 programs, monitor this for the period of extended 19 operation.
20 CHAIRMAN SIEBER: Thank you.
21 MR. CAHILL: With that, I was going to 22 turn it over to Chris to talk about some of the other 23 open items.
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117 1 items that most of which deal with extensions brought 2 about by Rev. 2 and the GALL which is issue 3 of GALL.
3 MR. MALLNER: That's correct.
4 CHAIRMAN SIEBER: Why don't we skip those 5 and go to the -- I think there's maybe two that really 6 aren't related to that.
7 MR. MALLNER: Okay, let's skip to the next 8 slide which has to do with submerged power cables.
9 The question was that we received from the staff was 10 whether or not we needed to do inspections of manholes 11 that were then driven based on rain storms, 12 hurricanes, etcetera. For Crystal River 3 there are 13 four manholes within the scope of license renewal. Of 14 them one is by the intake structure and has a sump 15 pump. There's one on top of the berm that's located 16 inside the hot machine shop that's completely enclosed 17 and not exposed to weather. And that leaves two 18 manholes of interest.
19 Those manholes are located on the berm.
20 They're well above the water table and we've looked in 21 these manholes recently and we found a couple of 22 inches of water, the last time we inspected these 23 manholes and the amount of water was more than two 24 feet below the latest cable tray in that manhole.
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118 1 frequency and it's really based on the design of the 2 manholes. As you can see at the inset, the top of the 3 manholes are one and a half to two feet above the berm 4 there and there's a plug that fits into the top that 5 has a seal on it to prevent water intrusion. And we 6 believe the annual inspections are adequate and you 7 don't need to do any additional inspections.
8 Also, we've looked at the area -- Crystal 9 River receives about 50 inches of rainfall a year and 10 because of that, like I said, we've done inspections 11 recently. We have found very little water inside the 12 manholes, so we don't believe we need to do any 13 inspections that are event driven.
14 CHAIRMAN SIEBER: The water table is 15 pretty close to the surface.
16 MR. MALLNER: But the water table -- okay, 17 to give you some idea of where everything is, where 18 that manhole is located is at about elevation 114.
19 CHAIRMAN SIEBER: Okay.
20 MR. MALLNER: And the groundwater table is 21 approximately at elevation 90.
22 CHAIRMAN SIEBER: All right.
23 MR. MALLNER: And the bottom of the 24 manhole is at about elevation 105. So the bottom of 25 the manhole is about 15 feet above the water table.
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119 1 CHAIRMAN SIEBER: Thank you.
2 MR. MALLNER: So that's why I don't 3 believe we need to do event-driven inspections.
4 MR. BARTON: So long-term, you go to an 5 annual --
6 MR. MALLNER: Yes, we do annual 7 inspections, that's correct.
8 Okay, we can skip the next slide. This 9 open item here is related to a further evaluation 10 recommended item that's in the Standard Review Plan 11 that's associated with non-regenerative heat 12 exchangers. And the issue was in the Standard Review 13 Plan whether or not it's required to do any current 14 inspections of non-regenerative heat exchangers. For 15 Crystal River, the heat exchanger in question would be 16 the letdown coolers and as you can see by that inset, 17 those letdown coolers are not amenable to any current 18 inspections. Those two form an Archimedes spiral 19 inside there and there's many tubes and it's going to 20 be extremely difficult to try to do any current 21 inspection.
22 So what we did, we went back and looked at 23 the operating history of these coolers and we noted 24 that we had leakage from these coolers early in plant 25 experience and we revised our design because they were NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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120 1 caused by flow-induced vibration. We lowered flow 2 rate. We've changed the heat exchanger design and we 3 hadn't had any leakage in these coolers since 1991.
4 Based on that, we believe that our design 5 issue has been resolved and that cracking due to 6 cyclic load is not applicable aging effect for Crystal 7 River letdown coolers. However, we still agree with 8 the further evaluation recommended item that SCC could 9 be possible and we've included these letdown coolers 10 within our one-time inspection program and we'll do as 11 part -- they will be part of our inspection population 12 for one-time inspection program. And similar to other 13 items that are in the GALL that are susceptible to 14 SCC, we will have the water chemistry program be 15 applicable and be a part of our one-time inspection 16 program population. We've provided this response to 17 the staff for their review and it's currently under 18 review.
19 The next open item is in regards to the 20 NUREG/CR-6260 locations. We were asked the generic 21 RAI that's been sent out to the current applicants on 22 whether or not the locations that we've selected for 23 our 6260 environmentally-assisted fatigue evaluations 24 are bounding for Crystal River. We did another review 25 which we've provided to the staff and we reviewed our NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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121 1 locations on a component by component basis and on a 2 material basis. As part of that review, we considered 3 bounding environmental penalty factors and also as 4 part of that review we did a qualitative evaluation of 5 risk significance which was related to the original 6 GSI 190 resolution for environmentally-assisted 7 fatigue.
8 Based on our review, we've concluded that 9 the evaluations we performed are bounding for 10 environmentally-assisted fatigue and again we provided 11 our response to the staff and are waiting on review.
12 CHAIRMAN SIEBER: We'll see what the staff 13 says.
14 MR. MALLNER: Yes. We have two 15 confirmatory items. The first confirmatory item is 16 related to a compressed air monitoring program. The 17 original license renewal application did not include a 18 compressed air monitoring program. Crystal River 19 assumed that downstream, the dryers, that we had a dry 20 air environment and we had no aging effects and our 21 interactions with the staff, they asked us questions 22 related to how do we guarantee that the environment 23 will continue through the period of extended 24 operation.
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122 1 the compressed air monitoring program consistent with 2 Revision 2 of the GALL in order to alleviate their 3 concerns about the potential of those lines containing 4 moist air in the future. So we provided them with a 5 new program consistent with Revision 2 of the GALL to 6 alleviate their concerns.
7 The second confirmatory item has to do 8 with the leak before break analysis TLAA evaluation we 9 had in the application. The original CLB analysis 10 only performed a qualitative evaluation of the cast 11 material and did a specific evaluation for transients.
12 When we did our license renewal evaluation, we 13 determined that there was enough new information to 14 drive us to do a qualitative evaluation of thermal 15 aging. However, we did not consider that portion of 16 the TLAA to be -- that portion of the analysis to be a 17 TLAA and we had originally resolved this TLAA using 18 Method I, that the original analysis was acceptable 19 for 60 years.
20 The staff disagreed and during a 21 teleconference we agreed to call the thermal aging 22 portion of that analysis, TLAA, and therefore we've 23 now resolved the analysis using method II which is 24 we've projected the analysis for 60 years. And we've 25 provided that to the staff and that's currently under NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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123 1 review.
2 That concludes that portion of the 3 discussion and I'll turn to --
4 CHAIRMAN SIEBER: Let me sum up what you 5 plan to talk about next. You're going to do steam 6 generator replacement, reactor vessel head replacement 7 and power uprate and in some respects those enhance 8 your ability to operate beyond the 40-year license 9 life but they're external to the review of the license 10 renewal and we wish you success in all of those 11 endeavors. You'll get your power uprates greater than 12 five percent which I think it will be. We'll be back 13 to talk.
14 MR. WILSON: We'll be back.
15 CHAIRMAN SIEBER: To talk. And if any of 16 the members have any questions --
17 MEMBER SHACK: Just a quick question on 18 the head. What's your head temperature?
19 MR. CAHILL: Lower head -- I can't give 20 you the exact number. It's like lower than Davis-21 Besse, but compared to other --
22 MEMBER SHACK: It can't be too much lower 23 though. Your hotleg is 604.
24 CHAIRMAN SIEBER: Yes, but it's usually a 25 degree or two --
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124 1 MR. CAHILL: It's not much.
2 CHAIRMAN SIEBER: Depending on how much 3 circulation you have. Any other questions?
4 MR. BARTON: Yes, I've got one on the 5 switchyard. I haven't seen this before. Since your 6 plant is located right on the Gulf of Mexico, you've 7 got the salt spray question on insulators, that issue.
8 And I noticed that you said the way you get around 9 that or solve that problem is a silicone coating that 10 presents salt spray from adhering and it's good for 11 ten years. What did you do to qualify that? Because 12 that's the first time I've seen somebody apply 13 silicone coating to insulators to get around this salt 14 spray, salt deposits on their insulators.
15 MR. MALLNER: We're going to have Mike 16 Heath, the supervisor of license renewal address that.
17 MR. HEATH: That's really not uncommon.
18 We used it in Brunswick and Crystal River. That's the 19 standard product for that purpose.
20 MR. CAHILL: We've had very good extensive 21 operating history with it. I'm not familiar with the 22 qualifications we've done on it, but it's something 23 that has worked very well for us.
24 MR. BARTON: I just want everybody to know 25 for ten years, this is the first time I've seen NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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125 1 anybody doing this.
2 MR. HEATH: We inspect it every four 3 years.
4 MR. BARTON: I had some other stuff, but 5 for the sake of time we can move on. I do have one 6 other one. On your socket welds, ASME Section XI, 7 your socket weld commitment, you agree to perform 8 volumetric exam of ten percent of the socket welds per 9 interval and you're going to do one third of those 10 that you would do at an interval prior to license 11 extension here. How many welds are we inspecting? I 12 don't know what your total population of socket welds 13 is. Are we talking about one or two welds or 14 something that's meaningful.
15 MR. MALLNER: The population is 16 approximately 60 socket welds, so 10 percent would be 17 6 per interval which would mean two per period. So we 18 intend to do at least two prior to the period of 19 extended operation which would be the equivalent of 20 three and one third percent of an interval.
21 So we'll have two done.
22 MR. BARTON: Is the staff happy with that?
23 I just think that's a small sampling.
24 MR. MALLNER: I'll leave that for the 25 staff to --
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126 1 MR. BARTON: So that's what I'm going to 2 do. That's it.
3 CHAIRMAN SIEBER: Okay. I think it's time 4 for a break, even though we were 15 minutes late. I'd 5 like to resume our meeting with staff presentation at 6 4 o'clock.
7 (Whereupon, the above-entitled matter went 8 off the record at 3:43 p.m. and resumed at 3:59 p.m.)
9 MR. HOLIAN: This is Brian Holian, 10 Director, Office of License Renewal. I'd just like do 11 brief introductions and then turn it over to the NRC 12 staff. From left to right and let me first check on 13 the region, we do have Lou Lake, the Senior Reactor 14 Inspector and Mark Franke, the Branch Chief for Region 15 II on line.
16 MR. LAKE: This is Lou Lake.
17 MR. HOLIAN: And Mark?
18 MR. FRANKE: Mark Franke here.
19 MR. HOLIAN: Good, you're coming through 20 loud and clear. And you can hear this discussion?
21 MR. FRANKE: Yes.
22 MR. HOLIAN: Good. All right, from left 23 to right across the front of the room is Meena Khanna, 24 our Branch Chief from the Division of Engineering. To 25 her left is Farhad Farzam, Senior Structural Engineer, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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127 1 Division of Engineering. Then we have Abdul Sheikh, 2 he's one of mine.
3 (Laughter.)
4 Senior Structural Engineer. We have Rob 5 Kuntz, the Senior Project Manager and Dr. Allen Hiser, 6 senior level in Division of License Renewal.
7 I wanted to comment briefly on kind of the 8 three Branch Chiefs that have been involved. Raj 9 Auluck is also here, Division of License Renewal 10 Branch Chief on Structural and Electrical. Between 11 Meena and the Branch Chief Mark Franke in the region 12 and Raj, you've got three different organizations and 13 divisions in NRC that have been, one, looking at the 14 restart applications of containment and of course, the 15 Division of License Renewals are not the open items on 16 what testing is appropriate as we head in towards the 17 period of extended operation.
18 So there has been coordination of all of 19 that. It's not in silos. They look at each other's 20 request for additional information. They kind of peer 21 check each other and go from there, so that 22 coordination has occurred.
23 There have been two public meetings at 24 headquarters. There was one initially after the 25 initial delamination event and that was in December of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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128 1 2009. And then there was a follow-up meeting that the 2 applicant referred to where a lot of the technical 3 information behind the repair costs of root cause and 4 repair was done in a public meeting here in the 5 Commission hearing room in June of 2010.
6 With that, I thought the staff, we do have 7 some open questions on the testing. It does get down 8 to some of the issues regarding what the applicant has 9 proposed for start-up testing and immediate testing in 10 that initial time, how much of that would be extended 11 long before the period of extended operation and in 12 the period of extended operation. That's kind of a 13 summary of where the staff's open items are.
14 I thought we'd start though with Meena 15 Khanna just addressing a few of the open comments that 16 she took notes on from her staff and then we can 17 briefly go over some of the other open items. And 18 then I'll also go into a deeper discussion on the 19 containment, if that's appropriate.
20 CHAIRMAN SIEBER: Okay, thank you very 21 much. Appreciate it.
22 MS. KHANNA: Thank you, Brian. I just 23 wanted to also add with respect to the containment 24 delamination issue, as you know, we've been supporting 25 Region II. We support the special inspection team as NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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129 1 well as IP50001 steam generator replacement. We also 2 have three independent contractors that we brought on 3 board as well, very skilled, very highly technical 4 folks that assist us with the review as well. So I 5 just wanted to mention that as well.
6 First of all, I think you guys have raised 7 a few questions, so we wanted to address those very 8 quickly. On the tendon configuration, Farhad, if you 9 want to address that, you guys had a question with 10 respect to --
11 MR. FARZAM: I took the note that you had 12 a question about tendon configuration.
13 CHAIRMAN SIEBER: Yes.
14 MR. FARZAM: Let me just explain what the 15 containment configuration is. It's a six buttress and 16 the tendons are 163 wires, 7 millimeter diameter.
17 CHAIRMAN SIEBER: Right.
18 MR. FARZAM: So it's kind of equivalent to 19 170 wire quarter inch diameter.
20 CHAIRMAN SIEBER: Right.
21 MR. FARZAM: So obviously the horizontals 22 go 120 degrees, every other buttress and verticals go 23 from the ring girder all the way to the tendon 24 gallery.
25 CHAIRMAN SIEBER: Right.
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130 1 MR. FARZAM: On the domes are three 2 families of 60 degrees.
3 CHAIRMAN SIEBER: Right.
4 MR. FARZAM: So that's really the 5 configuration of the tendons. Now I noticed that you 6 had a question about the repair. I think it's 7 important to know what the design basis of this 8 containment was originally. The post-tensioning that 9 applied to this containment was enough to counteract 10 1.5p, p being the design basis accident. And however, 11 the design basis allowed 212 psi. When the repair was 12 done, that 212 was neglected and it was zero tension.
13 That's why you see the rebar in the Bay 3-4.
14 CHAIRMAN SIEBER: Okay.
15 MR. FARZAM: And the other thing is you 16 need to make sure is when you open up the containment 17 when you detension locally and you open up the hole, 18 you have a redistribution of stresses to surrounding 19 stresses. So when you retension the containment, you 20 will not get all the prestress that you had 21 originally. So that's another factor that you see 22 rebar in Bay 3-4.
23 CHAIRMAN SIEBER: Okay.
24 MR. FARZAM: I hope this helps the -- go 25 ahead and you can ask a question.
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131 1 CHAIRMAN SIEBER: Well, it helps my 2 understanding and it's consistent with my conception 3 of it. But it is not an easy problem from a 4 structural and analytical viewpoint. I think it's 5 very difficult because you end up with two different 6 types of containment wall with different properties as 7 I understand it.
8 MR. FARZAM: That's correct.
9 CHAIRMAN SIEBER: And it's not clear 10 without really detailed analysis that you can -- a 11 global nondetailed analysis won't tell you everything 12 you need to know about stress and strain and 13 particularly on the boundaries of the repair.
14 MR. FARZAM: Well, let me go into a little 15 bit more detail on that.
16 CHAIRMAN SIEBER: Okay.
17 MR. FARZAM: The ANSYS model, the 18 structural analysis design basis calculations are 19 based on computer program ANSYS.
20 CHAIRMAN SIEBER: Okay.
21 MR. FARZAM: And what the licensee has 22 done is -- this particular calculation computer model 23 it tracks the loading as it happens. In other words, 24 the baseline is containment, nothing has happened to 25 it.
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132 1 CHAIRMAN SIEBER: Right.
2 MR. FARZAM: As they detension 10 vertical 3 and 17 hoop containment deflected, and then after they 4 remove concrete containment deflected and 5 redistributed, so the entire history has been captured 6 in that analysis.
7 CHAIRMAN SIEBER: Right, okay.
8 MR. FARZAM: And staff requested 9 parametric studies on modulus of elasticity of 10 concrete, new and old, to capture the sensitivity on 11 stress distribution of containment.
12 CHAIRMAN SIEBER: Okay.
13 MS. KHANNA: Thank you. Thanks, Farhad.
14 CHAIRMAN SIEBER: So the detailed analysis 15 has been done and is confirmed what you actually found 16 in the -- after this evolution has been completed.
17 MR. FARZAM: That's correct. I mean the 18 model even included the liner, liner plate in the 19 model, because liner plate takes load as you detension 20 and retension and we requested another analysis 21 without the liner in the model to understand if the 22 liner is not there, what would be the stress 23 distribution to concrete.
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133 1 not substantially, but a significant portion to the 2 overall strength of the containment.
3 MR. FARZAM: Right, I mean liner if you --
4 based on a design basis. It's a leak-type area.
5 CHAIRMAN SIEBER: That's right.
6 MR. FARZAM: And as far as being a 7 strength element or not, that's why we requested to 8 have two different analyses. One is Licensing -- what 9 they did is they include the liner in order to track 10 the load.
11 CHAIRMAN SIEBER: Right.
12 MR. FARZAM: Because that's the physics of 13 the problem. The liner is there. And we requested 14 another analysis without the liner to understand what 15 the stress distribution is, basically an envelope of 16 both.
17 CHAIRMAN SIEBER: Yes, but the liner 18 itself is not -- is more than just a membrane.
19 MR. FARZAM: Absolutely, and the ultimate 20 strength of the container, the liner will go into 21 tension and it will contribute to the structural 22 integrity, yes.
23 CHAIRMAN SIEBER: But the liner by itself 24 would be totally inadequate.
25 MR. FARZAM: Absolutely.
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134 1 CHAIRMAN SIEBER: Without the remaining 2 structure.
3 MR. FARZAM: Yes.
4 MS. KHANNA: Thank you. With that, Ali, 5 are you on the phone as well? Ali?
6 MR. REZAI: Yes, I am here.
7 MS. KHANNA: Okay, great. Ali, if you 8 don't mind addressing the question that the ACRS 9 members had with respect to the incident response and 10 your review of that to detect the delamination to 11 properly detect the delamination that Licensing had 12 done?
13 MR. REZAI: Yes, I have been asked to 14 evaluate the licensee's technique that has been used 15 to detect delamination created during detension and 16 they propose a technique called impulse response 17 method and this method has been used in other industry 18 to detect delamination in piles and columns and it's 19 useful for thick structure similar to a containment 20 building.
21 And so the licensee proposed this method 22 and did calibration. They basically did the studies 23 on this method under containment and first calibrated 24 the system, as well as did some trial testing and 25 after that they performed testing on the structure.
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135 1 Basically, this system is done 2 qualitatively and provides qualitative answers. That 3 means the system basically tells you what area is 4 delaminated and what area is not delaminated, meaning 5 that the data is taken at every foot by foot.
6 Basically, the structure is divided into grids of one 7 foot by one foot and at every foot they collect the 8 data and the system basically provides mobility value.
9 Mobility value is a range of numbers that indicates, 10 for instance, from zero to .4, if the range is below 11 .4 or the mobility number is below .4 indicates no 12 delamination of that section. If it's in between the 13 .4 and some other number, indicates it's inconclusive.
14 And if it's above some number indicates a 15 delamination.
16 So the error on this system basically in a 17 foot's range, so the licensee collected the data and 18 then took a core sample at locations that there was a 19 boundary between non-delaminated and delaminated 20 values of impulse response. And the core result 21 verified their findings. And that was basically my 22 analysis of their determination of extent of 23 delamination.
24 MEMBER ABDEL-KHALIK: Can this technique 25 detect more than one discontinuity?
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136 1 MR. REZAI: Are you indicating like --
2 MEMBER ABDEL-KHALIK: Parallel 3 discontinuities?
4 MR. REZAI: Are you talking about a 5 multiple delamination at different depths?
6 MEMBER ABDEL-KHALIK: Right.
7 MR. REZAI: That's a little bit difficult 8 to determine multiple delaminations at different 9 depths. The reason for that is the way it's 10 calibrated you get some sort of a depth so the system 11 becomes very sensitive to depth initial depths of the 12 structure that you are given. So if there are 13 different delaminations, it can detect, but it's kind 14 of in a gray side.
15 MEMBER ABDEL-KHALIK: How can it? I mean 16 don't you essentially just give an acoustic wave going 17 through and it's reflected at the first discontinuity?
18 MR. REZAI: No, this is not as a normal 19 acoustic application. Basically, what it does is you 20 hit the hammer and you vibrate the structure and the 21 structure, when the vibration goes and comes back, 22 basically it doesn't go and comes back. The whole 23 structure vibrates.
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137 1 hits delamination and comes back. It's the structural 2 response to that hammer impulse. And the mobility 3 value is basically the particle at the sensor, the 4 vibration of the particle at the sensor, divided by 5 this pulse that you impinge on the material.
6 So the way it's determined, the 7 delamination or affects the structure is how the 8 vibration of that structure, in other words, if the 9 structure is not delaminated the whole structure, the 10 whole entire solid part vibrates. The structure and 11 the mobility value becomes higher and if the structure 12 delaminated, then the part of the structure vibrates 13 and that's the mobility value. I hope I was able to 14 explain.
15 CHAIRMAN SIEBER: Sort of like ringing the 16 Liberty Bell without being able to see it.
17 MS. KHANNA: Okay, if you guys have any 18 further questions on that we can get back to you.
19 Thank you.
20 And George Thomas, if you could just 21 discuss the ABACUS question that will be great.
22 MR. HOLIAN: George Thomas is also a 23 member of the Special Inspection Team.
24 MR. THOMAS: I just want to clarify the 25 question of ABACUS. The ABACUS model was not used by NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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138 1 the licensee from a design basis calculation. One of 2 the outcomes of the root cause investigation was that 3 they determined that standard industry analysis tools 4 was a linear elastic method where incapable of 5 predicting delamination.
6 As part of the root cause investigation, 7 the licensee put on the computer simulation for which 8 they have to use more refined models capable of 9 predicting delamination. So have let the fracture 10 base nonlinear model using ABACUS to go there. And 11 the model was informed using forensic data collected 12 during this delamination.
13 MS. KHANNA: Great, thanks. And finally, 14 you had requested whether the staff was evaluating a 15 review of the liner. And we are conducting a liner 16 evaluation. As I indicated, we are supporting the 17 region. They've got the lead on this inspection 18 procedure, 50001, which containment liner is part of 19 the review. We are currently reviewing that. It's 20 still under review. We have not made any conclusions 21 and the reasons, as Lou will address later, will be 22 documented in their inspection report. Okay?
23 I'll turn it back over to Rob.
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139 1 outstanding question with whether the staff found the 2 applicant's approach for socket weld and inspections 3 prior to PEO, whether staff had found that acceptable 4 and why.
5 Dr. Hiser will address that question.
6 DR. HISER: This is Allen Hiser, License 7 Renewal. The applicant is doing 2 before the extended 8 period of operation, but they're also 10 percent 9 within each 10-year period, so they will ultimately 10 end up doing somewhere on the order of 14 out of the 11 60 socket welds which is beyond the guidance and 12 recommendations that are in the GALL report.
13 So the fact that they're doing a periodic 14 program is why we find the three and one third percent 15 or four PEO to be acceptable.
16 MR. BARTON: I just thought that two was 17 an awful small --
18 DR. HISER: It's 2 early, but then 12 19 coming through.
20 MR. BARTON: Gotcha, the operating period.
21 MR. KUNTZ: Okay. I guess we can start 22 with the prepared material now.
23 Like we discussed, my name is Rob Kuntz.
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140 1 points that were made by the applicant and get through 2 the presentation material as quickly as possible here.
3 This is just an overview of our 4 presentation material. So let's move on to the next 5 slide. The application came in on December 16th. As 6 Brian mentioned, we've delayed the schedule twice 7 actually because of the delamination issue, until we 8 have a better understanding of where they were before 9 we came to ACRS with our findings.
10 And like, I believe, the applicant 11 mentioned, the operating license expires in 2016. So 12 this is just a summary of the inspections and audits 13 that have been conducted. You can see the scoping and 14 screening audits were done back in 2009, as well as 15 the initial Region II inspection and we did a follow 16 up inspection in October of 2010. This gives the time 17 frame of the special inspection conducted in response 18 to the delamination.
19 The SER open items was issued December 20 14th. The next several slides are just mentioning 21 each of the open and confirmatory items that we'll 22 discuss in greater detail later in the presentation, 23 so I'll go ahead and plow through these next couple of 24 slides.
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141 1 staff found that the applicant had done a fairly 2 thorough job scoping the screening. There were a few 3 RAIs primarily related to clarifying the renewal 4 drawings, system attendant function and fire 5 protection. So that's just the initial discussion.
6 At this point I'll turn it over to Lou Lake. We'll 7 talk about the regional inspections as well as the 8 SIT.
9 Lou, are you on? Lou, are you still 10 there?
11 MR. LAKE: Hello, yes. I'm sorry. I had 12 it on mute for a while. I apologize. Can everybody 13 hear me well?
14 CHAIRMAN SIEBER: Yes.
15 MR. LAKE: Okay, I'd like to apologize for 16 not being there. Unfortunately, the ice and the way 17 Atlanta treats ice storms I can't get out so accept my 18 apology.
19 My presentation is basically in two parts.
20 The first part is going to discuss -- is going to be 21 focused on license renewal inspections and then it 22 will be followed by a brief discussion on the 23 containment delamination and associated issues.
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142 1 activities associated with license renewal inspection 2 programs whereby the NRC staff verifies the accuracy 3 of the licensee's Aging Management Program associated 4 with its request for license renewal under 10 CFR 50 5 Part 54.
6 Inspections are conducted in accordance 7 with NRC Inspection Procedure 71002 to verify the 8 applicant's license renewal program including support 9 activities are implemented consistent with the 10 requirement of CFR Part 54.
11 A site-specific inspection plan was 12 prepared and the inspection was scheduled to support 13 NRR's review of the application. The inspection was 14 conducted by a five-member team that consisted of 15 inspectors with experience in mechanical engineering, 16 electrical engineering, structural engineering, and 17 system and component testing and examinations.
18 Next slide, please.
19 The objective of these inspections are 20 focused on Aging Management Programs. Confirmed that 21 existing Aging Management Programs are working well 22 and to examine the applicant's plans for establishing 23 new Aging Management Program or enhancing existing 24 ones.
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143 1 in length and was conducted between July and August of 2 2009. It consisted of a review of 100 percent of the 3 applicant's 40 Aging Management Programs. We 4 interviewed personnel, examined records of past tests, 5 surveillances, operating experience, and corrective 6 action from existing Aging Management Programs.
7 We examined implementation plans for new 8 and expanded Aging Management Programs. We verified 9 inclusion of future tasks into established site test 10 tracking systems and inspected the material condition 11 of the plant by conducting plant walk-downs to verify 12 that equipment is being adequately maintained.
13 The inspection was completed on August 14, 14 2009 and the results of this inspection is documented 15 in the section of the report issued September 28, 16 2009.
17 Next slide, please.
18 As required by the initial inspection, a 19 follow-up inspection was conducted to further review 20 five Aging Management Programs that were not able to 21 be fully reviewed during the initial inspection due to 22 insufficient information and opened the request for 23 additional information.
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144 1 time inspection program and the internal surface and 2 miscellaneous piping and ducting component program was 3 conducted, including the new neutron absorbing program 4 for fuel pool A containing carborundum and fuel pool B 5 containing boral. We verified inclusion of future 6 tests into established site test tracking systems. We 7 inspected the material condition of the plant by 8 walkdowns including the inside of the containment and 9 a walkdown of the spent fuel pool A and B.
10 The inspection was completed on October 6, 11 2010 and the result of this inspection is documented 12 in an inspection report issued on November 10, 2010.
13 Are there any questions so far?
14 Next slide, please.
15 The inspection team concluded that the 16 existing programs credited to license renewal are 17 functioning well, that the implementation of both new 18 and existing Aging Management Programs provide 19 reasonable assurance that the intended functions of 20 plant systems, structures, and components related to 21 these programs will be maintained through the period 22 of extended operation.
23 The documentation supporting the 24 application was in an auditable and retrievable form 25 and new Aging Management Programs are as described in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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145 1 the license renewal application and in responses to 2 request for additional information.
3 Inspections of plant equipment conducted 4 during walkdowns found no significant adverse 5 conditions and it appears plant equipment was being 6 adequately maintained.
7 The applicant had established sufficient 8 implementation plans that were incorporated in the 9 plant action request system to track the committed 10 future actions to license renewal and to ensure that 11 they are completed.
12 Licensee's Aging Management Program will 13 be subject to additional NRC inspections in accordance 14 with Inspection Procedure 71003 prior to the extended 15 period of operation.
16 Next slide, please.
17 The position of the containment building.
18 As has been discussed previously by the applicant, a 19 delamination in a containment concrete wall formed in 20 September of 2009. To assess the circumstances 21 associated with the discovery of the delamination, the 22 Region II Administrator issued a special inspection 23 charter in October of 2009. The inspection began on 24 October 13, 2009 and was completed on September 2, 25 2010. The results of the inspection is documented in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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146 1 an inspection report issued on October 12, 2010.
2 The special inspection was conducted prior 3 to the completion of the applicant's planned 4 corrective actions. Corrective actions and repairs 5 are subject to an on-going inspection in accordance 6 with NRC inspection procedure 50001.
7 As previously mentioned, the root cause 8 was determined to be the scope and sequence of the 9 detensioning conducted in support of making the steam 10 generator opening and was limited to the area between 11 buttress 3 and 4. The delamination has been removed 12 and the containment wall has been restored.
13 Final repair activities are in process of being 14 completed.
15 Vertical cracks were observed when the 16 containment was further detensioned in preparation for 17 delamination removal and repair activities. Some 18 cracks were removed and those cracks that were less 19 than 10 mils were left as-is. The applicant plans to 20 monitor those cracks left as-is during retensioning, 21 during the SIT pressure test, and plan is to inspect 22 them one year after post-maintenance pressure test.
23 Also, in accordance with requirements of 24 10 CFR 50.55a and ASME Section XI, the applicant plans 25 to examine the containment surface at a frequency of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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147 1 every five years thereafter.
2 Continued monitoring of these vertical 3 cracks is currently an open issue that will be 4 discussed later as part of items, open item number 5 3.5-1.
6 Next slide, please.
7 Containment liner bulges have been 8 identified by the licensee and observed by NRC 9 inspectors. These bulges are located in between the 10 liner stiffeners and are independent of the 11 delamination formed in the concrete portion of the 12 concrete wall.
13 Review of examination records and 14 interviews of plant staff indicate that these bulges 15 were initially identified earlier in plant operation 16 and evaluated to be acceptable for plant operation.
17 Monitoring beyond 10 CFR 50.55a regulatory 18 requirements is currently an open item and will be 19 further discussed in the presentation of Open Item 20 3.5-1.
21 Cracking in the containment dome concrete 22 in 1970 prior to initial plant operation, a 23 delamination was also identified and repaired. The 24 delamination was in the form of a circle covering a 25 significant portion of the dome. During the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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148 1 activities associated with determining the extent of 2 the current delamination, Crystal River conducted IR 3 scans of a sample of the dome surface and identified 4 evidence of subsurface cracks in a localized area. It 5 was determined that this cracking was not associated 6 with the current delamination and that it was 7 associated with the repair conducted on the 8 delamination found in the 1970s.
9 As a result, essentially 100 percent of 10 the containment dome surface was examined by scanning 11 with IR and core bores were taken in suspect areas.
12 This investigation determined that the cracks 13 identified during this outage were localized along the 14 edge of the repair area and were not related to the 15 delamination recently identified.
16 NRC is in process of conducting 17 inspections of the scheduled licensee's post-18 maintenance inspections and testing and will conduct 19 additional license renewal inspections prior to the 20 period of extended operation in accordance with IP 21 71003.
22 CHAIRMAN SIEBER: Now is there operating 23 experience for this type of containment with events or 24 damage similar to that which Crystal River 3 has 25 observed and analyzed and is repairing at other plants NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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149 1 with this type of containment?
2 MR. SHEIKH: Not that I know of. This is 3 Abdul Sheikh. Not that I'm aware of.
4 CHAIRMAN SIEBER: Well, this is certainly 5 a lesson to learn for those plants who do have this 6 type of containment.
7 MR. BARTON: What caused delamination in 8 the dome?
9 CHAIRMAN SIEBER: That's unrelated to this 10 steam generator replacement.
11 MR. BARTON: I understand that.
12 CHAIRMAN SIEBER: It's not clear to me.
13 On the other hand, that was dispositioned some time 14 ago. And it has passed the integrated leak rate test.
15 MR. LAKE: It also passed the structural 16 integrity test and the integrated leak rate test.
17 CHAIRMAN SIEBER: Right.
18 MR. FARZAM: This is Farhad Farzam. I 19 just want to make a clarification. The 1976 dome 20 delamination was during construction.
21 CHAIRMAN SIEBER: Right. And other types 22 of containments other than post-tension containments 23 have cracks in the concrete structure. It's that the 24 other types of containments with rebar-type structure 25 for the strength and integrity of the containment is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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150 1 perhaps better understood because it's a more common 2 construction technique. This is relatively unique in 3 construction practice, so that draws interest to 4 issues that occur there. But I would hope that the 5 industry promulgates the knowledge of this particular 6 event to others so that we don't find other units of 7 similar construction having incidents which are costly 8 and cause a lot of downtime for the plant.
9 MS. KHANNA: And we also have an action 10 item to pursue this as a generic. We're looking into 11 either issuing an information notice or something as 12 well as soon as we get done with our review, we do 13 have that's an Action Item, we can definitely do that.
14 Okay? And we did talk to NEI. NEI's been involved.
15 They've got a data base of all the steam generator 16 replacement plans as well, so they're tracking that as 17 well.
18 MEMBER ABDEL-KHALIK: Could someone --
19 CHAIRMAN SIEBER: Sorry to interrupt the 20 presentation on the inspection process. You may 21 continue, sir.
22 MEMBER ABDEL-KHALIK: Well, can I just ask 23 if someone could physically explain why would the 24 original detensioning cause delamination while the 25 subsequent detensioning would cause vertical cracks?
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151 1 MR. FARZAM: Okay, you're talking about 2 during steam generator replacement?
3 MEMBER ABDEL-KHALIK: Yes.
4 MR. FARZAM: Okay, you're talking about 5 wall delamination?
6 MEMBER ABDEL-KHALIK: Right. Why did the 7 original cause delamination while the subsequent 8 detensioning cause vertical cracks physically?
9 MR. FARZAM: I think the subsequent 10 detensioning was the 155 hoop tendons and 64 -- and 11 155 went around the perimeter. It's 360 degrees 12 detensioning. The original prior to steam generator 13 opening, it was local. In other words, it was not 360 14 degrees.
15 So the phenomenon that went on prior to 16 steam generator opening is different of what went on 17 when you opened up the relaxed 360 degree and the --
18 as I recall, I guess Slide 61 of the public meeting 19 that the licensee had, the finite element analysis 20 that they replicated the vertical cracks showed that 21 because of the creep concrete, when the concrete was 22 relaxed, the steel responded immediately and created 23 tension, membrane tension in the wall and as it was 24 discussed, there is no particular rebar within the 25 depth of the containment wall. It's just outside.
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152 1 And that particular tensile stress overloaded the 2 concrete and created the vertical cracks.
3 MEMBER ABDEL-KHALIK: Okay, thank you.
4 CHAIRMAN SIEBER: Okay, I think the region 5 can continue.
6 MR. LAKE: Okay. Thank you. I'm on Slide 7 15 now. We talk about Containment Building restart 8 milestones and we have identified the following 9 milestones at Crystal River and that's retensioning of 10 the tendons which is currently in progress and it's 11 being monitored during inspections in accordance with 12 inspection procedure 50001. It's being implemented in 13 stages with completion scheduled some time in March.
14 Also, a structural integrity test is 15 planned after retensioning, followed by an integrated 16 leak rate test and the inspectors will review these 17 activities to verify the results are consistent with 18 the licensee's assessment of containment operability 19 and assumptions used in their design calculations.
20 Also, there are some remaining technical 21 issues on vertical cracks and containment liner bulges 22 that are being currently viewed by NRC staff. With 23 that, I'd like to thank you and I'll turn over the 24 rest of the presentation to Rob Kuntz.
25 CHAIRMAN SIEBER: Thank you very much, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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153 1 appreciate it.
2 MR. KUNTZ: Thanks, Lou. Next is the --
3 we'll go through the format of the SER. Section 3 is 4 the Aging Management Review. Section 3.0 discussed 5 the staff's review of Aging Management Programs and 6 3.1 through 3.6 are a discussion of the staff's review 7 of AMRs.
8 Just a summary of the Aging Management 9 Program you heard Lou describe 40 earlier. One has 10 been added since it is related to the tendon stamped 11 to monitor the aging of the tendons in containment.
12 So that was just added December 8th, so that's why 13 there's 41 and Lou only looked at 40 during the 14 inspections.
15 So we'll start with the open items. I 16 thought I'd leave the containment after the other 17 ones, so we get through these and get the containment 18 one.
19 I lumped the one-time inspection selection 20 leaching as a similar item. That's for the components 21 inspected, how many, and how they would decide the 22 components to be inspected. The applicant responded 23 to this RAI December 29, so staff still is in the 24 process of reviewing that response.
25 Similar with the cracking due to SSC and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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154 1 cyclic loading. We received that response the end of 2 December and the staff is still reviewing that.
3 And structures monitoring and masonry wall 4 program were similar to the previous ones that we just 5 received a response to these and we're in the process 6 of reviewing. So I'm going to go over Buried Piping 7 and Tanks Inspection Program. The staff submitted to 8 the applicant as an RAI similar to other applicants 9 based on industry operating experience. The 10 applicant's response stated that the cathodic 11 protection is available for most of the buried piping 12 except for a small portion of the condensate system 13 and all the nuclear service in decay heat seawater 14 system and proposed augmented inspection for those 15 pipes of those components.
16 The applicant also stated the coatings and 17 backfill quality are acceptable based on plant 18 specification and has been validated by inspection 19 results. The applicant proposed alternate inspection 20 methodology, remote field transfer coupling for buried 21 concrete piping. That response came in December 8th 22 and the staff is still finalizing its review.
23 CHAIRMAN SIEBER: How reliable is the 24 licensee's cathodic protection program? Does it meet 25 the 90 percent criteria?
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155 1 MR. LANE: Bill Holston, can you answer 2 that, please? How reliable is the applicant's 3 cathodic protection?
4 MR. HOLSTON: Yes, my name is Bill 5 Holston, Division of License Renewal. And the 6 applicant in 2004 did an evaluation of their cathodic 7 protection program and found some gaps. They've 8 corrected those gaps and put long-term corrective 9 actions in place and from GALL AMP perspective we look 10 at a minimum of the five years prior to the period of 11 extended operation having 90 percent availability 12 which they will achieve.
13 CHAIRMAN SIEBER: Thank you.
14 MR. KUNTZ: Moving on to the next slide, 15 inaccessible medium-voltage cables. The applicant 16 discussed this one also. They provided a response 17 that include to the staff's request which asked how 18 they would manage end scope cables that potentially 19 could be submerged and they increased the scope of the 20 program to include cables below four kilovolts and as 21 the applicant discussed, they didn't mention in their 22 cover what they'd do in an event-driven response, 23 heavy rains. So we're still waiting a response from 24 the applicant.
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156 1 item, Open Item 3.5-2. The background of the staff's 2 perspective, there was a large area of concrete that 3 had been removed and replaced compared to other steam 4 generator replacements. All the vertical tendons had 5 been either reinstalled or retensioned. One hundred 6 fifty-five of the 282 hoop tendons will be reinstalled 7 or retensioned. The applicant has installed 8 monitoring sensors to track the condition of the two 9 types of concrete and the applicant plans to perform 10 an SIT as mentioned and ILRT.
11 The applicant is performing containment 12 concrete in post-retensioning rework. As a repair 13 replacement activity pursuant to 10 CFR 50.55a, ISI 14 requirements, and ASME Code Section XI, Subsection IWL 15 Staff notes that the code is the minimum 16 standard and the unique nature of the repair may 17 require the applicant to consider inspection 18 requirements more than what was prescribed in the code 19 or potentially --
20 CHAIRMAN SIEBER: The unit is still shut 21 down?
22 MR. KUNTZ: Correct.
23 CHAIRMAN SIEBER: When do you expect 24 restart?
25 MR. KUNTZ: March?
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157 1 PARTICIPANT: First quarter of this year.
2 CHAIRMAN SIEBER: Thank you.
3 MEMBER REMPE: Can I ask for some 4 clarification. You said that you did detect some 5 cracking in the dome, but it was repaired in 1976, but 6 it isn't related at all to this repair, but is that an 7 indicator that repaired concrete cracks?
8 MR. SHEIKH: No. Those cracks are the 9 ones, the cracks they found were as a result of the 10 repair found on the dome.
11 MEMBER REMPE: So the repair was well done 12 is what you're saying?
13 MR. SHEIKH: It was well done. Because 14 they added some reinforcement which helps that, you 15 know, because they cut the containment at that very 16 location. And when they cut it it was a potential of 17 a crack and that is in the -- there was some 18 delamination detected. But that was -- the situation 19 was analyzed and those cracks can be resisted by the 20 additional reinforcement provided in that area during 21 that repair. That's my understanding.
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158 1 concrete. The frequency of the planned integrated 2 leak rate test, how the applicant will monitor the 3 bulges that are left in service. There is 4 surveillance and inspection requirements for the pre-5 stressed tendons, how the effects of the through 6 thickness vertical cracks will be monitored, and also 7 additional information on the applicant's TLA on the 8 pre-stressing tendons.
9 The applicant -- the staff received 10 responses to these requests on or after December 8th 11 of this year for 2010, so we're still in the process 12 of reviewing those responses and the staff is 13 considering the need for additional information 14 related to the dome cracks, so that's still a 15 possibility.
16 MEMBER ABDEL-KHALIK: So I guess the 17 explanation that I received earlier about why the 18 vertical cracks versus delamination pertains to the 19 fact that your -- in the subsequent detensioning, it 20 was done in a sort of broader azimuthal distribution 21 and that's why you got the vertical cracks.
22 So what makes you sure that the extent of 23 the vertical cracks is only within that area that was 24 opened up?
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159 1 Farzam.
2 MEMBER ABDEL-KHALIK: So these cracks 3 extend 360 degrees.
4 MR. FARZAM: Outside Bay 3-4, there are 5 also vertical cracks.
6 MEMBER ABDEL-KHALIK: And those are 7 throughwall cracks?
8 MR. FARZAM: The licensee has done core 9 bores to identify if they're going through the 10 thickness. I believe one of the core bores showed 11 that it's about 12 inches or so. Their analysis is 12 assuming its through thickness.
13 MEMBER ABDEL-KHALIK: Thank you.
14 MR. BARTON: But they're saying when they 15 retension those are going to close up?
16 MR. FARZAM: That's the open question that 17 we are reviewing at this point. For sheer transfer, 18 obviously, you need -- you have a clamping force and 19 you have to -- that clamping force needs to give you 20 that sheer transfer across the crack, yes. I mean 21 that's the main system that you have. You don't have 22 any rebar going through the cracks. It's just post-23 tensioning --
24 MR. BARTON: So how are you going to know 25 whether that happens or not? Or doesn't it matter?
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160 1 MR. FARZAM: Well, the basic assumption 2 is that you have sheer transfer because you have 3 contact and through the thickness on a crack. So 4 that's another issue that we're reviewing right now 5 about the monitoring of the vertical cracks after its 6 retension, the containment is retensioned. That's the 7 critical point to confirm that what you have assumed 8 in your analytical work is physically happening.
9 That's an open item at this point the staff is 10 reviewing.
11 MR. BARTON: Good luck in proving that 12 one.
13 MS. KHANNA: I just want to note that --
14 MEMBER ABDEL-KHALIK: With respect to what 15 you said, so the assumption is that sheet transfer is 16 by friction between these two interfaces?
17 MR. FARZAM: That is correct because 18 there's no other element across the crack.
19 MS. KHANNA: I just wanted to reiterate as 20 well, but as Lou had indicated this was an issue that 21 we're looking at from the current operating term as 22 well as we're bringing it, yes, correct. We're 23 looking at it.
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161 1 obviously, is 1.25 pressure plus OBE and 1.OP times 2 pressure plus SSE. And since the containment is being 3 retensioned, the pre-stressing force that you have 4 give you the clamping force for that particular, for 5 those particular load combinations. As far as the 6 design basis OP and SSE, it's not as high as other 7 plants.
8 MR. KUNTZ: Ready to move on? That's it 9 for the containment presentation.
10 Next is the one confirmatory item from the 11 SER Section 3. The RAI originally proposed no aging 12 effect in the dry air environment for compressed air 13 components. Staff noted that this was inconsistent 14 with the GALL report. Through a series of RAIs, the 15 applicant added the Compressed Air Monitoring Program.
16 Staff just needs to confirm that that program as 17 described by the applicant is consistent with the 18 GALL.
19 Moving on to SER Section 4, this is a 20 section detailing the one plant specific TLAA has to 21 do with bedrock in solution. There's one open at one.
22 Confirmatory Item Section 4 and also the open item 23 3.5-1 also refers to Section 4-5 which is the TLAA 24 pre-stressed and tendons.
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162 1 environmentally-assisted fatigue. The staff asked the 2 applicant if the analysis presented in the LRA was 3 bounding for components not necessarily discussed in 4 NUREG/CR-6260.
5 Any questions on that open item? That 6 response came back also on December 29th, so the staff 7 is in the process of reviewing that.
8 The final item is confirmatory item 9 Section 4. The applicant also described this. The 10 original LRA did not consider CASS components and 11 leak-before-break analysis is the TLAA of that.
12 That's why that was and the applicant is going to 13 amend the LRA to address this.
14 That ends the prepared slides from the 15 staff. I'm going to turn it back over to Brian for 16 any closing comments.
17 MR. HOLIAN: Brian Holian. We knew that 18 the containment issue is the primary issue today for 19 closing out this SER. Related to the non-containment 20 open items, they're very similar to NRC=s recent 21 license renewal applications in our final close out.
22 We expect to be able to work through those items over 23 the next several months and schedule a final SER.
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163 1 clearly focused on getting the containment operable, 2 the root cause took a long time. Even the 3 retensioning, when you look at it. The fact that 4 we're having to take that long kind of shows the 5 extent of the problem and the issue that was caused.
6 So it's a touchy issue. I'm glad you got a focus of 7 that today.
8 The region has monitoring with Division of 9 Engineering help on the restart aspects here. They'll 10 be taking a look at those vertical cracks and make 11 sure that they close up according to the model.
12 We've heard a little bit more today on 13 doing a one-year check of that. That's where license 14 renewal has come in with these open items and RAIs.
15 Okay, we see that plan, but you've got six years 16 before the extended period and we'd like to see a plan 17 for some additional checks in that time and some 18 commitments for what we'll do in the extended period.
19 We have kind of a relatively weaker aggregate in the 20 delamination in the dome early on with some cracking 21 that you've now just recently identified, most 22 probably due to the original construction. But we'll 23 probably ask different questions to verify that and 24 continue to check the dome.
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164 1 and make sure they have a robust Aging Management 2 Program, we're still left open. We'll take our time 3 with that and inform the Committee if we have a tough 4 time closing those open items. You'll see us extend 5 as needed.
6 CHAIRMAN SIEBER: Is that it?
7 MR. HOLIAN: That's it.
8 CHAIRMAN SIEBER: Okay. I guess my 9 comment at this point in time is that I consider that 10 the applicant has done a pretty good job in analyzing 11 and responding to the very adverse condition that is 12 difficult to understand, difficult to analyze, and I 13 see the applicant putting attention to detail and to 14 coming up with the adequate solution that will restore 15 the containment to an operable condition.
16 Like the staff, I still have some 17 questions that I believe will be resolved and the 18 process will come to completion on this. I also 19 understand that the bulk of the open items is due to 20 the GALL transition from Rev. 1 to Rev. 2 and will 21 ultimately be closed.
22 And so I do appreciate the applicant's 23 presentation and the analysis that they have done and 24 their explanations in this meeting because I feel I 25 have a much better understanding than I did even at NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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165 1 noon today.
2 I also appreciate and understand that the 3 work that staff has done and I think even though this 4 is probably the 65th or 66th application that's been 5 reviewed that the staff has continued to do excellent 6 work and I think that you're right on the money as far 7 as tracking the issues that you are and understanding 8 the issues that are resolved in a satisfactory way.
9 And so I actually can offer congratulations to both 10 the applicant and the staff to having proceeded at 11 least this far, but we are not to the end of the 12 quest. And there's still work to be done.
13 What I'd like to do is take a few minutes 14 just to ask our members if they have any comments and 15 also our consultant and former member John Barton who 16 has done extensive review on this.
17 John, I'd like to start with you. Do you 18 have any additional questions, comments?
19 MR. BARTON: I think you covered it pretty 20 well, Jack. I was impressed with the applicant's 21 presentation. I think this is a tough subject and I 22 think that they were well prepared and could answer 23 all of our questions basically. That's all I can say.
24 The proof is going to be in the pudding as to how 25 they come through with thing, but I think they did a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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166 1 good job explaining what they got and what they found 2 and how they intend to recover.
3 CHAIRMAN SIEBER: Well, it's almost like 4 the movie "The Wizard of Oz" and we are standing 5 outside the castle seeing what's going to be inside.
6 Perhaps I could go around the room and ask 7 if anybody, any of the members have questions or 8 comments?
9 MEMBER SHACK: No additional ones. Again, 10 I thought it was a good presentation today. I have a 11 much better understanding of the problem than I did 12 when I started. I think there's still work to be 13 done, still questions to be addressed, but things seem 14 to be moving forward.
15 Learning more about reinforced concrete, 16 between this and the Shield Building, I'm an old steel 17 man, so this is all new to me.
18 CHAIRMAN SIEBER: Well, three more license 19 renewals, I might be able to repair my driveway.
20 (Laughter.)
21 Joy?
22 MEMBER REMPE: I don't have any comments 23 other than to also add my thanks to the applicant and 24 the staff for their presentations. I don't have any 25 questions.
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167 1 CHAIRMAN SIEBER: Said?
2 MEMBER ABDEL-KHALIK: I do appreciate the 3 presentation by both staff and the applicant, but I 4 must admit that I'm left with more questions than what 5 I started out with. And therefore I'm just wondering 6 if it would be appropriate for this Subcommittee to 7 devote a meeting to a detailed review of the analyses 8 performed to support the work related to the 9 delamination root cause and the subsequent repair 10 work.
11 CHAIRMAN SIEBER: I would not object to 12 that. And we have not gone into the details neither 13 here nor is it available in the documents that we 14 read. And they are difficult to understand.
15 MEMBER ABDEL-KHALIK: I guess this is 16 something that we need to discuss, whether it would be 17 appropriate --
18 MEMBER SHACK: It would be good to have a 19 consultant.
20 MEMBER ABDEL-KHALIK: Right, but even for 21 the Committee itself to, the Subcommittee itself to 22 spend a full meeting reviewing all these analyses.
23 CHAIRMAN SIEBER: We could perhaps discuss 24 that at the Full Committee meeting this week and see 25 what the members would want to do.
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168 1 MEMBER ABDEL-KHALIK: Sure.
2 MEMBER SHACK: Thank you.
3 CHAIRMAN SIEBER: Thank you. Sanjoy?
4 MEMBER BANERJEE: I just came in, but is 5 this coming up in front of the Full Committee?
6 CHAIRMAN SIEBER: Not in the near future.
7 MEMBER BANERJEE: So the discussion would 8 be just sort of decide whether we wanted to take a 9 look at this?
10 CHAIRMAN SIEBER: If we had additional 11 discussions on the containment analyses and the repair 12 process that would be in addition to our ordinary 13 process of doing the license renewal that it is a 14 unique analysis that took a lot of skill by a lot of 15 people to perform it and understand it and find it 16 acceptable and we are not at that point yet. So there 17 are still questions to be asked. I would not oppose 18 an additional meeting on that.
19 MEMBER ABDEL-KHALIK: Would the staff and 20 the applicant be able to support such a meeting?
21 MR. HOLIAN: This is Brian Holian, License 22 Renewal. The answer is yes. We would and the 23 applicant would have to.
24 (Laughter.)
25 They have done a lot of work with NRR NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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169 1 staff, but even we realized going into this, I think a 2 Full Committee scheduled in June, they've got a lot to 3 do here to -- on this retensioning. I think the March 4 start up, now if it all goes according to plan, it 5 will validate the model and the results will be good.
6 Any other perturbation to that or any other 7 perturbation to coming to agreement with the staff on 8 some of these open items through the Aging Management 9 Program already kind of makes us at risk for making an 10 April SER final SER date to get to -- end of April.
11 So that has to extend anyway, but even if that 12 schedule did stay and we would fit a Subcommittee 13 meeting in, I think that would be appropriate.
14 CHAIRMAN SIEBER: We will take that into 15 consideration, I'm sure, when we decide whether we 16 need an additional meeting or not because it is 17 important to everyone that's involved.
18 Okay, with those comments, I want to thank 19 everybody that's here who have made presentations and 20 contributed to the work effort in this regard. I can 21 tell you that I am leaving this room with a much 22 better feel than I had when you started at 1:30 this 23 afternoon. So I thank you all for that.
24 If there are no other additional comments, 25 this meeting is adjourned.
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170 1 (Whereupon, at 5:03 p.m., the meeting was 2 concluded.)
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AGENDA
- Site Description
- Open and Confirmatory Items
- Major Upgrades 2
Site Description CR-3 is a Babcock and Wilcox NSSS Plant Gilbert Associates was the A/E Operating License Approved December 3, 1976 Licensed for 2609 MWt (912 Mwe)
Key Features Pressurized Water Reactor Large Dry Containment Once-Through Steam Generators Gulf of Mexico Ultimate Heat Sink Helper Cooling Towers on Discharge Canal 3
License Renewal CR-3 License Renewal Application is the fourth Progress Energy application Core Corporate team developed all applications License Renewal staff involved in industry working groups Chaired Mechanical and Electrical Working Groups Involved with NUREG-1801 revisions Site involved in IPA development Reviewed all Aging Management Programs 4
License Renewal Application Development Scoping and Screening Consistent with 10 CFR 54 and NEI 95-10 Sources included Equipment Database, design basis documents, plant procedures, FSAR, and docketed correspondence Aging Management Reviews Consistent with 10 CFR 54 and NEI 95-10 Plant operating experience utilized Consistency with GALL a priority 5
GALL Consistency Application was based on NUREG-1801 Rev. 1 Aging evaluations are 82% consistent with GALL (standard notes A through D) 41 aging management programs 17 programs are consistent with GALL 22 programs have exceptions or enhancements 2 plant specific programs 6
Time-Limited Aging Analyses Reactor Vessel Neutron Embrittlement Metal Fatigue Environmental Qualification of Electrical Equipment Concrete Containment Tendon Prestress Containment Liner Plate, Metal Containments, and Penetrations Fatigue Plant-specific TLAA Bedrock Dissolution from Groundwater 7
Commitment Management CR-3 has made 30 License Renewal commitments Tracked by Progress Energys commitment tracking process Implementation Plan is developed for each commitment 8
Open and Confirmatory Items OI-3.5-1: Containment Delamination Root Cause Delamination repair Impacts on the liner Liner bulges Pre-startup and post-startup inspections NEI 94-01 Test Intervals 9
Containment Delamination Root Cause SGR Opening Dimensions
@ Liner 23 6 x 24 9
@ Concrete Opening 25 0 x 27 0 Yellow line denotes boundary of delamination 10
Containment Delamination Root Cause Problem Statement: While creating an opening in the containment building wall to support the steam generator replacement project, a gap in the concrete was discovered. The gap is in close proximity to horizontal tendons. This gap was not anticipated and based on industry operating experience, other similar projects have not encountered the same condition.
- Comprehensive Team Commissioned
- Progress Energy personnel - expertise across fleet
- Industry utility peers
- External industry expertise
- Laboratory and Testing Expertise 11
SGR OPENING SEQUENCE &
IDENTIFICATION OF DELAMINATION Note - Tendon depiction is for illustrative purposes and is not an exact scale 12
Containment Delamination Root Cause - Strategy Analysis Cross Check Root Cause Analysis Condition Assessment Implement Repairs Design Basis Analysis Repair Alternatives Analysis Analysis Cross Check 13
Containment Delamination Root Cause Initial Focus on Condition Assessment
- Non-Destructive Testing (NDT) of Containment Surfaces
- Use of Impulse Response (IR) Method - over 8,000 IR data points
- Ground Penetrating Radar (GPR)
- Comprehensive on all accessible areas
- Concrete Core Bores
- Over 170 core bores performed
- Ranged from 1 to 8 diameter, 6 to 32 long
- Validated IR data, along with boroscopic inspections
- Laboratory testing 14
Containment Delamination Root Cause
- 75 potential Failure Modes (FM) investigated
- 67 FMs refuted
- Remaining 8 FMs combined for Root Cause Analysis to determine their significance
- Existing Industry Analysis Techniques Predicted Acceptable Margin to Delamination at CR3
- Investigation Required Development of New Finite Element Analysis Tools
- Progressively increasing complexity
- 360o global containment model
- Visco-elastic / non-linear model
- Model includes individual tendons, rebar, liner, etc.
- Sub-models (1 mesh) provide higher resolution of localized behavior 15
Root Cause Analysis Summary
- Conclusions
- Design acceptable for Normal and Emergency Operations
- Construction was in accordance with design
- Delamination occurred during the outage
- New state-of-the-art analytical methods had to be created to analyze containment response 16
Root Cause Analysis Summary
- Root cause
- De-tensioning scope and sequence resulted in redistribution of stresses that exceeded tensile capacity
- Could not have been predicted based on existing information and models at that time
- Multiple pre-existing conditions contributed to the delamination (design, materials, etc) 17
Containment Repair Phases Phase
- 1. Stress Relief Cut
- 2. De-Tensioning
- 3. Delamination Removal
- 4. Concrete Placement
- 5. Re-Tensioning
- 6. Post Repair Testing 18
Design Basis & Repair FSAR Structural Design Parameters
- Containment Design Features Remain Unchanged
- Approach done via 10 CFR 50.59
- Containment Design Basis Maintained
- Leak-tight structure to contain fission products in design basis Loss of Coolant Accident
- Elastic response to design basis loading preserved to protect liner
- Design loads and combinations based on operating, accident and applicable code requirements
- Load factors applied to provide safety margin 19
Delamination Repair Detension Containment to facilitate delamination removal 155 horizontal and 64 vertical tendons Detailed sequence analysis Tendons in repair area of Bay 3-4 removed Delamination fully removed Bay 3-4: Elevation 157-10 to 240 Variations in depth of concrete removal Vertical crack removal Install reinforcement New radial reinforcement Additional horizontal and new vertical reinforcement 20
Delamination Removal Hydro-Excavation Completed 21
Radial Anchor Installation For Concrete Placement Below 176 22
Reinforcement Installation Inner layer of Rebar Mat in Fully Excavated Area 23
Final Reinforcement Installation 24
Mock-up Testing - Reinforcement Installation 25
Delamination Repair Place concrete - 5 foot lifts On site batch plant Retensioning 155 horizontal & 64 vertical tendons Detailed sequence using partial (2 step) tensioning 80 remaining vertical tendons reset to original construction value Owner-elected SIT / ILRT 26
Impacts on the Containment Liner Exposed containment liner and concrete reinforcement were thoroughly examined in accordance with Code Minor indications noted during these examinations Some from repair effort; some original construction All assessed and repaired 27
Impacts on the Containment Liner Additional concrete cracking was also noted.
All areas were evaluated and/or repaired to restore the materials and surface conditions to meet the design requirements.
28
Impacts on the Containment Liner Design impacts on the Containment liner due to the repair have been evaluated.
The results of the calculations show that there is no impact on the current design basis of the Containment liner.
29
Containment Liner Bulges
- Observed between vertical stiffeners (18 apart)
- Bulges had always been monitored & evaluated per IWE Program - qualitatively
- Extent of condition bounded by laser scanning and visual inspections
- UT measurements have confirmed no generalized corrosion or liner wall thinning 30
Laser scan 31
Dome Bulges 32
Containment Liner Bulges
- Finite Element Analysis completed
- Verified no impact and conformance to liner design requirements
- FEA established allowable bulge size: 1.82
- No loading condition would create / result in a bulge
- Construction tolerances
- Have tracked most limiting bulges
- Dome bulge 1.312 +/- .125 (manual measurement)
- All bulges are within acceptance criteria
Post Repair Testing - Pressure Tests
- Integrated Leak Rate Test (ILRT) required per ASME XI code
- For removing / replacing liner in SGR opening
- Pressure test for repaired concrete
- Plan to perform an elective Structural Integrity Test (SIT)
- Normally a one-time initial construction structural test
- Test intent: measures structural integrity and deformation at 1.15 peak design pressure (63.3 psig)
Pre- startup Monitoring and Inspections ASME Section XI - Repair/Replacement Required
- Detailed visual examination of new concrete surfaces
- Detailed visual examination of the liner repairs
- Detailed visual examination of tendons and anchorage areas (for manipulated tendons)
- Containment pressure test (ILRT) for liner and concrete ASME Section III - SIT Scope
- Visual examination of accessible portions of containment (including concrete and liner).
- Mapping of surface cracks
- Displacements, temperatures, and pressures 35
Pre- startup Monitoring and Inspections (cont.)
- Owner Elected - Augmented
- Laser scanning (of liner bulges)
- Liner bulge measurements
- Vertical crack width measurements
- General visual examination of all accessible concrete surfaces (outside repair areas)
- Embedded strain gauges and thermocouples
- Laser scanning (building displacements)
- Acoustic sensor monitoring
- Impulse response testing
- Periodically monitor containment concrete condition outside Bay 3-4 to ensure no unexpected changes via NDE methods
- Monitoring condition in Bay 3-4 via installed containment sensors 36
Post-startup Monitoring and Inspections ASME Section XI - Repair/Replacement Required
- General visual examination of new concrete surfaces
- Augmented Tendon examination and testing of tendons affected by the repair/replacement activities Owner Elected - Augmented
- Vertical crack width measurement
- Liner bulge measurements
- Periodically monitor containment concrete condition outside Bay 3-4 to ensure there are no unexpected changes via NDE methods
- Monitoring concrete condition inside Bay 3-4 via installed containment sensors 37
Pre-Startup and Post-Startup Inspections Test Intervals per NEI 94-01 CR-3 is committed to 1995 Rev. 0 of NEI 94-01 Section 9.2.3 Extended Test Intervals
- Allows Type A (ILRT) testing to be extended to once every 10 years based on two consecutive successful Type A tests CR-3 previously established acceptable Type A history and extended this interval to once every 10 years Section 9.2.4 Containment Repairs and Modifications
- Requires Type A test when repairs could affect leakage integrity
- Does not require re-establishment of acceptable test history to apply Type A extended test intervals for repairs to Containment 38
- CR-3 maintaining test interval
OI-3.5-1: Containment Delamination Open Item requested how our experience will be incorporated into the ASME Section XI, Subsection IWE and IWL programs Also whether a plant-specific program is necessary to manage aging of the containment Changes to the CR-3 IWE/IWL Program Those required by the ASME Section XI repair/replacement requirements contained in Articles IWL -2000 and IWL-4000 Additional augmented Owner-elected inspections include:
Vertical crack width inspection - assure crack widths remain the same or reduce in size Liner bulge heights and wall thickness measurements CR-3 not developing plant-specific containment aging program 39
Open and Confirmatory Items OI-3.0.3.1.9-1: One-Time Inspection Sampling Sampling methodology consistent with NUREG-1801,Rev. 2 OI-3.0.3.2.10-1: Selective Leaching of Materials Sampling Sampling methodology consistent with NUREG-1801,Rev. 2 OI-3.0.3.1.10-1: Buried Piping and Tanks Aging Management Inspection activities reconciled with NUREG-1801, Rev. 2 40
Open and Confirmatory Items OI-3.0.3.1.19-1: Submerged Power Cables Concerned with event driven manhole inspections One manhole has a sump pump One manhole is located in the Hot Machine Shop Two are located on the berm Manholes are sealed Located well above the water table Annual inspections find little water accumulation Annual Inspection frequency to be informed by operating experience 41
Open and Confirmatory Items OI-3.0.3.2.13-1: Masonry Wall Program inspection frequency Inspection frequency changed to five years OI-3.0.3.2.14-1: Structures Monitoring Program quantitative acceptance criteria Acceptance criteria per ACI 349.3R A baseline inspection will be performed prior to the period of extended operation 42
Open Item OI-3.3.2.2.4.1-1 OI-3.3.2.2.4.1-1: Cracking due to stress corrosion cracking and cyclic loading One-time Inspections vs. Eddy Current Testing Cracking due to cyclic loading (associated with high cycle fatigue)
Not applicable to the letdown coolers Cracking due to SCC can be detected by inspections performed by One-time Inspection AMP 43
Open Item OI-4.3.3-1 OI-4.3.3-1: Environmentally-Assisted Fatigue Analysis Bounding of NUREG/CR-6260 Locations Review performed by material and component Bounding Fen considered Qualitative Assessment of Risk Significance EAF evaluations performed are bounding 44
Confirmatory Items CI-3.0.3.1.11-1: Compressed Air Monitoring Program GALL Report Consistency Compressed Air Monitoring Program added Program based on NUREG-1801, Rev. 2 Staff is evaluating determination of consistency CI-4.3.4.2-1: Thermal Aging of Cast Austenitic Stainless Steel (CASS)
Disposition for the CASS RCP casings and nozzles under 10 CFR 54.21(c)(1)(ii) 45
Recent and Ongoing Major Projects Reactor Vessel Head Replacement Head inspections identified cracking of Alloy 600 nozzle due to PWSCC Head replaced in 2003 Alloy 690 selected due to its superior resistance to PWSCC Replacement Head project included cable replacement and other operational improvements 46
Recent and Ongoing Major Projects Steam Generator Replacement Decision based on Alloy 600 mitigation Tube plugging limits Steam generators replaced in current outage New generators use Alloy 690 tubes Replacement project included FW riser and RCS piping replacement 47
Recent and Ongoing Major Projects Power Uprates Measurement Uncertainty Recapture (2007)
Secondary plant thermal efficiency improvements (2009)
Full Extended Power Uprate - licensed change to rated thermal power scheduled for Refuel 17 (2012)
Significant modification scope in 2009 through 2012 48
Major Power Uprate Modifications Primary plant changes scheduled for next outage Cross-tie of low pressure injection trains Improve core flood line break performance Enhance boron precipitation mitigation Enhanced primary-to-secondary heat transfer capability Larger, safety-related ADVs with alternate low pressure control value Increased Emergency Feedwater and High Pressure Safety Injection flow 49
Major Power Uprate Modifications Secondary plant new equipment High and low pressure turbine Electrical generator including exciter, partial bus and bus duct cooling Replaced, upgraded or added several secondary heat exchangers Replaced/upgraded secondary pumps, motors and/or rotating elements 50
Questions Questions?
51
Advisory Committee on Reactor Safeguards (ACRS)
License Renewal Subcommittee Crystal River Unit 3 Nuclear Generating Plant (CR-3)
Safety Evaluation Report (SER) with Open Items January 12, 2011 Rob Kuntz, Project Manager Office of Nuclear Reactor Regulation 1
Presentation Outline
- Overview of CR-3 License Renewal Review
- SER Section 2, Scoping and Screening review
- Region II License Renewal Inspections
- SER Section 3, Aging Management Programs and Aging Management Review Results
Overview of LRA
- License Renewal Application (LRA) Submitted December 16, 2008
- Applicant: Florida Power Corporation
- Facility Operating License DPR-72 expires December 3, 2016
Audits and Inspections
- Scoping and Screening Methodology Audit
- June 23-26, 2009
- Aging Management Program (AMP) Audits
- July 13-17, 2009
- Region II Inspection
- 2 weeks in July/August 2009
- 1 week follow-up in October 2010
- Special Inspection in response to containment delamination October 2009-September 2010 4
Overview of SER
- Safety Evaluation Report (SER) with Open Items issued December 14, 2010
- Component selection for the One-Time Inspection Program (OI-3.0.3.1.9-1)
- Component selection for the Selective Leaching of Materials Program (OI-3.0.3.2.10-1) 5
Overview of SER (cont.)
- Inspection frequency for the Masonry Wall Program (OI-3.0.3.2.13-1)
- Quantitative inspection criteria for the Structures Monitoring Program (OI-3.0.3.2.14-1)
- Cracking due to stress-corrosion cracking and cyclic loading in stainless steel non-regenerative heat exchanger components (OI-3.3.2.2.4.1-1)
- Environmentally assisted fatigue analysis locations (OI-4.3.3-1) 6
Overview of SER (cont.)
- Aging management of buried and underground piping and tanks (OI-3.0.3.1.10-1)
- Aging management of potentially submerged power cables (OI-3.0.3.1.19-1)
- Aging management of the containment (OI-3.5-1)
- SER contains 2 Confirmatory Items (CIs)
- Compressed Air Monitoring Program consistency with the GALL Report (CI-3.0.3.1.11-1).
- Classification of thermal aging of CASS RCP casing and nozzles (CI-4.3.4.2-1) 7
SER Section 2 Summary
- Structures and Components Subject to Aging Management Review
- Section 2.1, Scoping and Screening Methodology
- Methodology is consistent with requirements of 10 CFR 54.4 and 54.21
- Section 2.2, Plant-Level Scoping Results
- Systems and structures within the scope of license renewal are appropriately identified in accordance with 10 CFR 54.4
- Sections 2.3, 2.4, 2.5 Scoping and Screening Results
- SSCs within the scope of license renewal are appropriately identified in accordance with 10 CFR 54.4(a), and those subject to an AMR in accordance with 10 CFR 54.21(a)(1) 8
Regional Inspection -
License Renewal Inspections Program Implementation
- License renewal chapter - MC 2516
- License renewal inspection procedure - IP 71002 9
Regional Inspection -
License Renewal Inspections Program Implementation
- Objective
- First Team Inspection
- Examine records
- Examine implementation plans
- Verify material condition of plant was adequately maintained 10
Regional Inspection -
License Renewal Inspections Program Implementation
- Follow-Up Inspection
- Reviewed 5 AMPS Open from Initial Inspection
- Conducted plant walk-downs 11
Regional Inspection -
License Renewal Inspections Program Implementation
- Inspections concluded
- existing programs credited for license renewal are functioning well.
- Applicant had established AMP implementation plans
- Region II will follow up during a future IP 71003 inspection 12
Regional Inspection -
License Renewal Inspections Program Implementation
- Condition of Containment Building
- Special Inspection
- Delamination - Cause, extent and repair
- Vertical Cracks 13
Regional Inspection
- Condition of Containment Building (Contd)
- Liner Bulges
- Cracks in Containment Dome 14
Regional Inspection
- Containment Building Restart Milestones
- Successful Retensioning
- Successful Structural Integrity Test
- Successful Integrated Leak Rate Test 15
Section 3: Aging Management Review
- Section 3.0 - Aging Management Programs
- Section 3.1 - Reactor Vessel & Internals
- Section 3.2 - Engineered Safety Features
- Section 3.3 - Auxiliary Systems
- Section 3.4 - Steam and Power Conversion System
- Section 3.5 - Containments, Structures and Component Supports
- Section 3.6 - Electrical and Instrumentation and Controls System 16
SER Section 3 3.0.3 - Aging Management Programs
- 41 Aging Management Programs (AMPs) presented by applicant and evaluated in the SER Consistent Consistent Consistent Consistent with with GALL with exception with exception &
enhancement enhancement Existing 10 4 8 5 (27)
New 7 5 (12)
The LRA also included 2 plant specific AMPs 17
SER Section 3 Open Items
- One-Time Inspection Program, OI-3.0.3.1.9-1 and Selective Leaching of Materials Program, OI-3.0.3.2.10-1 Both items relate to the components inspected by the One-Time Inspection and Selective Leaching of Materials Programs The staff is reviewing the applicants response
- Cracking due to SCC and Cyclic Loading OI-3.3.2.2.4.1-1 Inspection techniques for non-regenerative heat exchangers exposed to treated water The staff is reviewing the applicants response 18
SER Section 3 Open Item
- Structures Monitoring Program, OI-3.0.3.2.14-1 Acceptance criteria for the Structures Monitoring Program inspections The staff is reviewing the applicants response
- Masonry Wall Program, OI-3.0.3.2.13-1 The inspection interval for components within the scope of the Masonry Wall Program The staff is reviewing the applicants response 19
SER Section 3 Open Item
- Buried Piping and Tanks Inspection Program (OI-3.0.3.1.10-1)
- Staff submitted buried pipe RAI to applicant
- Overview of response
- Cathodic protection available except for small portion of condensate system and all of nuclear service and decay heat seawater system, augmented inspection proposed
- Coatings and backfill quality are acceptable based on plant specific specifications, validated by inspection results
- Alternative inspection methodology proposed for buried concrete piping
- Staff finalizing review 20
SER Section 3 Open Item
- Inaccessible Medium-Voltage Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Program, OI-3.0.3.1.19-1
- The applicants proposed aging management for potentially submerged cables did not include information related to event driven actions
- The staff is awaiting additional information from the applicant 21
SER Section 3 Open Item
- Containment Aging Management, OI-3.5-1
- During the Fall 2009 outage a delamination was discovered in the containment concrete
- Applicant is in the process of completing testing, analysis, and repairs to the containment
- Applicant is performing containment concrete and post-tensioning rework as a repair/replacement activity pursuant to the 10 CFR 50.55a inservice inspection program in accordance with ASME Code Section XI, Subsection IWL
- CR-3 containment rework is extensive and unique and the need for additional commitments is being evaluated 22
SER Section 3 Open Item
- Containment Aging Management, OI-3.5-1 (cont.)
- The staff has open questions related to the aging management of the CR-3 containment structure:
- Concrete inspection methods and frequency
- Integrated leak rate test frequency
- Monitoring bulges in the liner plate
- Prestressing tendons surveillance and inspection
- Monitoring of the through thickness vertical cracks in the concrete containment shell during the period of extended operation
- Prestressing Tendon TLAA
- The staff is reviewing the applicants response to these items 23
SER Section 3 Confirmatory Item
- Compressed Air Monitoring Program, CI-3.0.3.1.11-1
- Staff requested additional information on aging management of compressed air system components
- In November 2010 the applicant added the Compressed Air Monitoring Program
- Staff needs to confirm that the applicants program is consistent with the GALL Report 24
SER Section 4: Time-Limited Aging Analyses
- Section 4.1 - Identification of Time-Limited Aging Analyses
- Section 4.2 - Reactor Vessel Neutron Embrittlement
- Section 4.3 - Metal Fatigue
- Section 4.4 - Environmental Qualification of Electrical Equipment
- Section 4.5 - Concrete Containment Tendon Prestress
- Section 4.6 - Containment Liner Plate, Metal Containments, and Penetrations Fatigue Analysis
- Section 4.7 - Other Plant-Specific time-Limited Aging Analylses 25
SER Section 4 Open Item
- Environmentally-Assisted Fatigue Analysis, OI-4.3.3-1
- The staff questioned whether the locations in the LRA considered locations beyond those identified in NUREG/CR-6260 and if the locations considered are bounding for the plant
- The staff is reviewing the applicants response 26
SER Section 4 Confirmatory Item
- Thermal Aging of CASS RCP Components, CI-4.3.4.2-1 (TLAA of Leak-Before-Break Analysis of RCS Loop piping)
- The original LBB analysis used fracture toughness of ferritic material to analyze CASS RCP components due to limited CASS data in the 1980s.
- The applicant updated analysis.
- The applicant did not consider thermal aging of CASS as a TLAA in LRA. The staff did not agree.
- During a recent teleconference with the staff, the applicant to disposition as a TLAA in accordance with 10 CFR 54.21(c)(1)(ii) 27