ML12332A234
| ML12332A234 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/18/2012 |
| From: | NRC Region 4 |
| To: | |
| References | |
| NRC-1798 | |
| Download: ML12332A234 (46) | |
Text
Official Transcript of Proceedings
NUCLEAR REGULATORY COMMISSION
Title: Augmented Inspection Team Exit Meeting with Southern California Edison Company DVD 1/4
Docket Number: (n/a)
Location: San Juan Capistrano, California
Date: Monday, June 18, 2012
Work Order No.: NRC-1798 Pages 1-46
NEAL R. GROSS AND CO., INC. Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1 UNITED STATES OF AMERICA 1 NUCLEAR REGULATORY COMMISSION 2 + + + + +
3 AUGMENTED INSPECTION TEAM EXIT MEETING WITH SOUTHERN 4 CALIFORNIA EDISON COMPANY 5 + + + + +
6 MONDAY 7 JUNE 18, 2012 8 + + + + +
9 SAN JUAN CAPISTRANO, CALIFORNIA 10 DVD 1/4 11 + + + + +
12 The meeting convened in the Community Hall 13 at the San Juan Capistrano Community Center at 25925 14 Camino Del Avion, San Juan Capistrano, California, at 15 6:00 p.m., Richard Daniel, presiding.
16 NRC STAFF PRESENT:
17 RICHARD DANIEL, Facilitator 18 THOMAS BLOUNT 19 ELMO COLLINS 20 GEORGE CRAVER 21 EMMETT MURPHY 22 JOHN REYNOSO 23 JOEL RIVERA-ORTIZ 24 GREGORY WARNICK 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 2 PRESENT: (CONTINUED) 1 GREGORY WERNER 2 3 ALSO PRESENT:
4 PETER DIETRICH, Southern California Edison Co.
5 DOUGLAS BAUDER, Southern California Edison Co.
6 THOMAS PALMISANO, Southern California Edison Co.
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 3 P-R-O-C-E-E-D-I-N-G-S 1 (10:10 a.m.)
2 FACILITATOR DANIEL: (Joins during 3 progress) with you tonight. First gentleman to the 4 right -- we'll start to the right -- is regional director 5 for Region IV, the NRC, Elmo Collins.
6 Immediately to his left is Tom Blount. He 7 is the acting director for division of reactor safety.
8 The gentleman in the red shirt is Greg 9 Werner. He is the branch chief in the AIP team lead.
10 And finally the guy with the good haircut 11 there is Greg Warnick, senior resident inspector.
12 Peter Dietrich, Southern California, soon 13 I'm going to allow you to introduce your own folks.
14 MR. DIETRICH: Yes. Thank you. Good 15 evening. Pete Dietrich, the senior vice president and 16 chief nuclear officer for Southern California Edison, 17 and we are pleased to be here tonight to be able to talk 18 about the status of our steam generator situations with 19 concerned members of the public and other stakeholders.
20 MR. BAUDER: Good evening, Doug Bauder, 21 state vice president, San Onofre.
22 MR. PALMISANO: Good evening. I'm Tom 23 Palmisano, vice president of engineering, projects and 24 site support.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 4 FACILITATOR DANIEL: Okay. So without 1 further ado, I'm going to turn this over to Mr. Elmo 2 Collins. Elmo?
3 MR. COLLINS: Thank you Rick. I hope the 4 microphone is working.
5 FACILITATOR DANIEL: Hang on a second.
6 MR. COLLINS: Does that sound better? I 7 want to make sure that everyone --
8 Is this better? I hope everyone can see 9 me. I might need a stool you know, maybe. Maybe a 10 pulpit, you know, like church, but not that, I'm not 11 going to do that tonight. Thank you Rick.
12 Southern California residents, Mr.
13 Dietrich and other Edison employees, members of the 14 media, NRC representatives, good evening. I think I 15 would also like to introduce to you tonight another NRC 16 representative who is here. This is Tom Hipschman.
17 He is a technical assistant for the NRC chairman -- Tom's 18 in the back there -- the NRC Chairman Dr. Gregory Jaczko.
19 So we are glad Tom could join us tonight for the meeting. 20 Thank you, Tom, for being here.
21 I want to thank everyone for taking the time 22 to come out tonight to hear the Nuclear Regulatory 23 Commission present results of our augmented team 24 inspection.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 5 I can see we have a large crowd. I trust 1 that represents the large amount of interest that you 2 have here in the results and what's going on at San 3 Onofre. 4 I expect that many of you had to travel to 5 get here and so I appreciate the time, the effort that 6 you made to come and listen to what you have to say to 7 you tonight.
8 We all know that both units at San Onofre 9 are shut down because of what has proved to be very 10 difficult technical issues which their steam generators.
11 And I'll just start tonight by saying, so 12 far these issues are not resolved to the NRC's 13 satisfaction. Understandably --
14 (Applause) 15 MR. COLLINS: Understandably, I think there 16 is a lot of concern on your part, and I think that concern 17 is warranted.
18 For tonight's meeting we are here to present 19 the team's preliminary results to Edison, licensee, and 20 to you tonight, and we are going to talk to you about 21 those results, and NRC is glad to be here to share with 22 you what we know so far at the end of this stage of our 23 review. 24 This is a different public meeting from what 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 6we normally conduct. As Rick indicated, this is an NRC 1 inspection exit meeting. This marks the end of the 2 augmented team inspection which we started several 3 months ago and what you are going to hear tonight are 4 the preliminary inspection results.
5 There's no inspection report yet. That's 6 to come, we are guessing, in about 30 days. But tonight 7 you will hear what the inspection team found.
8 Additionally, the augmented inspection teams are 9 directed to focus on fact finding and information 10 gathering.
11 We have not yet made any decisions about 12 the resumption of power operations at San Onofre. Nor 13 have we made decisions about whether violations occurred 14 as a result of that inspection.
15 Those will be indicated to you, there is 16 requiring additional follow-up -- as follow-up items 17 when the team gives its findings. So I ask you tonight 18 to keep the issues that the team describes within that 19 context, remembering that the issues are not final agency 20 conclusions.
21 Rick talked about the comment and question 22 period we are going to have after we complete the business 23 part of the meeting. I think, at the risk of stating 24 the obvious, I know there are a lot of questions out 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 7 there, and so we are going to be here to answer those 1 questions.
2 We'll tell you what we know and we'll tell 3 you when we don't know, and we'll tell you when we think 4 more work is needed, and I think the questions are going 5 to fall into all three of those categories.
6 I'll also just indicate for you, tonight's 7 meeting is what NRC views as the first in a series of 8 public meetings that we are going to have to conduct 9 associated with the follow-up on these technical issues.
10 We are going to be conducting additional 11 inspection. We are going to be getting submittals from 12 Edison in writing that we'll be following up on, so as 13 they work through the issues and the NRC inspects them, 14 we will continue to conduct public meetings with you.
15 We do believe additional work by Edison is 16 needed and we do believe additional NRC inspection is 17 needed, and that will have to happen before NRC is in 18 a position to make a decision about the acceptability 19 of a resumption of power operations at San Onofre.
20 I want to thank you again for being here, 21 and we hope the meeting is informative for you, and with 22 that, I think Tom Blount will introduce the Augmented 23 Inspection Team, and we'll get into our presentation.
24 MR. BLOUNT: Thank you, Elmo. Is this all 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 8right for everyone. I kind of thought we'd go through 1 that. Sorry. I would like to offer my thanks and 2 appreciation for everyone coming out this afternoon, 3 or this evening, as well.
4 Before we get into the inspection results 5 itself, I did want to take just a couple of minutes and 6 give you some appreciation or perspective regarding the 7 team and the team's background.
8 We recognize that this is an important and 9 pretty serious issue, and the agency as a whole engaged 10 in this inspection team and provided the resources 11 necessary to support that.
12 We had support from not only Region 4, but 13 from our four other offices as well, including Research 14 and our Nuclear Reactor Regulation. Region 2 also 15 supplies some support.
16 Some of the talent that we had on this team 17 included a steam generator tube integrity engineer, a 18 thermal hydraulics specialist, steam generator material 19 engineer, quality assurance and control engineer, design 20 and evaluation engineer, all led by a Branch Chief from 21 Region 4, Greg Werner, who is going to give you the AIT 22 results here momentarily.
23 This team had over 130 years of total 24 experience that they brought to the table on this issue, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 9 not only as the team was doing their work, but we also 1 had the rest of the agency engaged in supporting our 2 efforts. 3 So I just wanted you to be aware, we took 4 this very seriously and want to get the right resources 5 to apply to this issue and will continue to do so.
6 With that, then, I'd like to ask Greg 7 Warnick if he'd give us an overview of the event and 8 the steam generators themselves.
9 MR. WARNICK: Sure, thank you very much.
10 Good evening. I'd just like to give a high level 11 overview of the steam generator tube leak event, the 12 licensee's response to that event, and what I personally 13 observed on January 31st, 2012.
14 The San Onofre plant is designed to rapidly 15 detect small amounts of radioactivity, small amounts 16 of leakage from the reactor system to the steam system 17 using sensitive radiation monitors that continuously 18 monitor and sample for radioactivity, samples of steam 19 that makes it way from the steam generator to the turbine 20 generators.
21 Procedures are in place that should, on 22 indication of steam generator tube leaks, actions are 23 prescribed to put the plant into a safe condition to 24 protect public health and safety.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 10 Finally, operators are trained on these 1 types of events such that they can quickly diagnose 2 problems, implement procedures and make the necessary 3 decisions to minimize any radioactive release to the 4 environment.
5 On the afternoon of January 31st, I had just 6 returned to my office from performing a plant tour as 7 part of an inspection. At that time, I heard a PA 8 announcement about a secondary plant system radiation 9 alarm. 10 John and I, John is a Resident Inspector, 11 we were both in the office. We went directly to the 12 control room when we heard that PA announcement. Our 13 offices are less than 100 yards from the Control Room, 14 so we were there within moments.
15 Both John and I went there and observed 16 actions to ensure that -- to assess the conditions and 17 ensure that the appropriate actions were being taken.
18 Upon arrival, I determined that the plant had 19 appropriately responded to the tube leak by identifying 20 leakage from the Reactor Coolant System and alerting 21 the operators to the abnormal condition before any 22 licensed release limits had been exceeded.
23 The operators responded in accordance with 24 their procedures to accurately diagnose a steam 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 11generator tube leak. They accurately assessed 1 conditions to determine that a rapid power reduction 2 and a plant shutdown was necessary.
3 After the plant was shut down, the operators 4 promptly isolated the affected steam generator to 5 terminate the radiation release and continued on to cool 6 down and depressurize the plant.
7 Because of the plant design, the 8 established procedures and the skill and training of 9 the operators, SONGS Unit 3 was placed into a safe 10 condition and the radioactive release that did occur 11 was minimized.
12 Our regional experts have independently 13 quantified the release and concluded that it was only 14 a very small percentage of the release limits allowed 15 by the plant license, such that the release associated 16 with this event did not represent a threat to workers 17 on site, to the public or to the environment. Next slide 18 (Question off-mic) 19 MR. WARNICK: Excuse me?
20 PARTICIPANT: What percentage?
21 (Question off-mic) 22 MR. WARNICK: It's a very small percentage 23 and that will be a -- go ahead and bring that up during 24 the question and answer period and I'll be happy to answer 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 12 that. 1 MEMBER OF AUDIENCE: And what was it that 2 was released, what kind of radioactivity?
3 (Question off-mic) 4 FACILITATOR DANIEL: Folks, hang on a 5 second. We're going to have a question and answer period 6 of time, comments and everything. Let the gentleman 7 finish his presentation and we will take your questions 8 at the appropriate time, okay? Thank you.
9 MR. WARNICK: Okay, again to reiterate, I 10 work at the plant every day, went to the Control Room 11 and assessed conditions. I'd like to now just talk 12 briefly about the steam generator function and some of 13 the structural components so that you will understand 14 some of the terms as we go through the balance of this 15 presentation.
16 The function of -- or the purpose of a steam 17 generator is essentially to make steam out of water.
18 It does this by acting as a large heat exchanger that 19 transfers heat from the primary radioactive system to 20 the clean steam system where it boils water into steam.
21 Hot radioactive water enters into the 22 bottom of the tube area and travels up through the inside 23 of the tubes, around the U-bend, back down to the cold 24 side of the bowl area and returns to the reactor to be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 13 reheated.
1 The clean secondary water enters into the 2 steam generator, it flows down around the outside of 3 the tube bundle, it is then directed up around the outside 4 of the tubes of the tube bundle region, where it is heated 5 up, it boils into steam and that steam acts as the top 6 of the steam generator to go to the turbine to make the 7 electricity.
8 Now I'll point out a few other structural 9 components, just, again, to aid in understanding of terms 10 we'll be using throughout the balance of this meeting.
11 A divider plate separates the hot and cold 12 bowl areas. That divider plate also helps to direct 13 flow of the primary water up through the U-tubes. It 14 also acts as a support for the divider plate and the 15 steam generator internals.
16 It is hard to see in this picture, but the 17 vertical section of the tube bundle is supported by tube 18 support plates. Those tube support plates provide 19 structural support to that vertical section.
20 In this picture, again, it's hard to see 21 but there are small holes throughout the tube support 22 plates. There are several of them that go up through 23 that vertical section. There are also flow channels 24 throughout the middle of the tube bundle region.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 14 The upper U-bend section of the tube bundle 1 is supported by a system of anti-vibration bars and 2 retainer bars. The steam generators are 65 feet tall, 3 they are 14 feet in diameter and they have a little less 4 than 10,000 tubes throughout them to perform that 5 function of transferring heat to the water.
6 It was one of these tubes in one of these 7 steam generators, one of these 10,000 tubes that 8 developed a leak, and resulted in the event that I just 9 briefly highlighted, that happened on January 31st.
10 ***time test 103406 11 FACILITATOR DANIEL: Folks, we are going 12 to take a short break here. Basically we have too many 13 people in the room, over capacity and we are going to 14 take a short break and move some folks out in the 15 courtyard on the side -- over on this side of the 16 building.
17 So, there are speakers out there and I 18 promise you I will come out and take your questions.
19 So if you could slide out the door. So you folks along 20 the back wall, if you move outside.
21 (Pause for organization of audience) 22 MR. COLLINS: I appreciate everyone's 23 cooperation. I apologize that we have to take this pause 24 and it's a disruption to our meeting, but this is, we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 15have been informed, important for safety, and important 1 for adherence to the fire code. So thank you so very 2 much for giving us this consideration.
3 (Pause while audience organized) 4 FACILITATOR DANIEL: Gil Leone (phonetic), 5 could you come back so I can speak with you please?
6 Gil? 7 (Off mic discussion about facility director 8 and fire code) 9 FACILITATOR DANIEL: For those folks that 10 are still standing there, okay, all right. We are going 11 to continue. Sign down, please. If you want to hold 12 up your sign, you can go outside and hold it up, but 13 not while you are seated.
14 (Off-mic remarks) 15 FACILITATOR DANIEL: I understand, but I 16 asked at the beginning, I asked at the beginning, that 17 signs be held in the back, because we are afraid somebody 18 might get hit in the head. We had that happen in another 19 meeting. 20 Okay, so -- ready? All right. We are going 21 to hear from Mr. Greg Werner here.
22 MR. WERNER: Good evening. I am Greg 23 Werner, the Augmented Inspection Team leader. I am 24 going to go ahead and briefly discuss the decision to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 16 conduct the augmented inspection.
1 During the pressure testing of the 129 tubes 2 on the Unit 3 steam generator, eight of the tubes failed 3 to meet the strength requirements necessary for tube 4 integrity.
5 Because the teams failed, this resulted in 6 conducting augmented inspection. Even before we made 7 a decision to perform the augmented inspection, two 8 Region 4 inspectors were already on site, accomplishing 9 the Unit 2, in-service inspection of the steam 10 generators.
11 This was part of the normal NRC inspection 12 program. We always complete an in-service inspection 13 that looks at 100 percent of the tubes after the first 14 outage for a replacement steam generator.
15 After the tube leak on Unit 3, we also 16 brought in Emmett Murphy from headquarters to assist.
17 Emmett has over 30 years of steam generator experience.
18 SONGS inspected 100 percent of all the steam 19 generator tubes on Unit 2 and 3, almost 40,000 tubes.
20 The NRC independently reviewed and analyzed the results 21 of the tube inspections and based upon our review of 22 the type of flaws on the Unit 3 tubes and the large number 23 of tubes with deep wear and over a long length of the 24 tube, the NRC had very good reasons to believe there 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 17 had been multiple failures of tubes on Unit 3.
1 So even before the first tube failed, Region 2 4 was working to put together an inspection team and 3 inspection charter. Because of this, we had inspectors 4 on site during the pressure testing.
5 The Augmented Inspection Team was initially 6 on site for two weeks. However, the team has continued 7 to review large quantities of documents, including the 8 cause evaluations, the 50.59 evaluations, draft 9 operational assessments, thermal hydraulic and 10 vibration computer simulation models, as well as 11 numerous other documents.
12 In addition, various team members, 13 including myself, have traveled back to SONGS to observe 14 expert panels on the cause evaluation, computer 15 simulation operational assessment.
16 To date, the Augmented Inspection Team has 17 expanded well over 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> associated with this issue. 18 Next slide, slide 11.
19 As Tom Blount mentioned earlier, 20 individuals with specialized expertise were brought in 21 from Region 4, Region 2, Office of New Reactors, the 22 offices of nuclear reactor regulation research at 23 headquarters in Rockville, Maryland.
24 I'm going to discuss the key items or 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 18objectives that the augmented team was tasked to look 1 at. We developed an event time line to look at the 2 design, construction, shipping, installation and 3 operation of both unit steam generators, reviewed 4 information to determine the causes. We looked at the 5 operational activities on the units to see if there was 6 impacts associated with those. We compared the 7 differences in the design manufacturing between the two 8 units, reviewed quality assurance and quality control 9 associated with the design and manufacturing of both 10 units' steam generators. We also reviewed 11 implementation of the generic communications and 12 industry lessons learned, to see if they incorporated 13 lessons learned that we gathered over the last 30 or 14 so years of steam generator use, reviewed the steam 15 generator simulation models. We also collected 16 information for the NRC risk assessment. We also looked 17 at other areas such as radiological controls that Greg 18 discussed.
19 One of the key areas that we wanted to 20 understand was the differences between Units 2 and 3.
21 Why was there more wear on Unit 3 than Unit 2, because 22 essentially the designs were identical?
23 It's important to note that for a number 24 of items we not only looked at what SONGS did, but we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 19also gathered information from Mitsubishi. We looked 1 at what the residents collected during the rapid shutdown 2 of Unit 3. We wanted to make sure that the operators 3 of the plant responded appropriately to the event.
4 The team looked at hundred and hundreds of 5 documents, including design, manufacturing and 6 operational information. We did our own independent 7 comparison of the information between the units. We 8 compared manufacturing information with design 9 information to check to see if the steam generators are 10 built in accordance with the design.
11 Where there were differences, we reviewed 12 the justification or the associated change 13 authorizations. Slide 12, please.
14 Now I plan to discuss what the Augmented 15 Inspection Team found. Throughout the US nuclear 16 industry, this is the first time that more than one steam 17 generator tube failed pressure testing.
18 As I discussed earlier, because of the 19 failure of the Unit 3 tube leak, 100 percent of the tubes 20 were inspected with subsequent pressure testing of 129 21 of those tubes on Unit 3.
22 During this pressure testing on Unit 3, 23 eight tubes failed. The pressure testing identified 24 the strength of the eight tubes was not adequate, and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 20 structural integrity might not be maintained during an 1 accident.
2 It is important that both SONGS and the NRC 3 understand what occurred and why. This is a serious 4 safety issue that must be resolved to prevent further 5 failures from occurring again. This information will 6 be shared throughout the nuclear industry.
7 SONGS did use multiple independent 8 consultants and steam generator manufacturers.
9 Personally I have never seen such a vast collection of 10 experts working together. They had academia, 11 independent consultants, industry experts from 12 different utilities as well as the industry itself, and 13 they also had four different steam generator designer 14 and manufacturers looking at the issues.
15 Next slide. These next two items that I'll 16 be discussing are really the most important items that 17 the NRC identified during inspection activities. These 18 are the ones that everybody, including us, were 19 interested in.
20 Actions will have to be taken to address 21 these to prevent the vibration that leads to the 22 tube-to-tube wear from occurring again.
23 The team identified the primary cause of 24 the unexpected tube wear was higher than expected flow 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 21 velocities in the steam generators.
1 Early in our inspections, we independently 2 developed a simplified mathematical thermohydraulic 3 computer simulation model of the steam generators in 4 Units 2 and 3.
5 Using this, we determined that the computer 6 simulation used by Mitsubishi during the design of the 7 steam generators had underpredicted velocities of steam 8 and of water inside the steam generators by factors of 9 three to four times.
10 San Onofre also had three other steam 11 generator vendors conduct computer simulation. The 12 results of their computer simulation also showed 13 significantly higher steam velocities and confirmed our 14 results. 15 Now the next item that I am going to discuss 16 deals with the differences between Unit 2 and 3. We 17 looked at a number of different items. However we only 18 identified one item that we could essentially determine 19 as the cause.
20 The cause of the difference in the tube wear 21 between the Units 2 and 3 is associated with the 22 manufacturing differences of the tubes and 23 anti-vibration bars.
24 For Unit 3, the anti-vibration bars do not 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 22 come in contact with the tubes as tightly as they do 1 on Unit 2, along with the higher steam and water flows 2 created to the conditions necessary for the high 3 vibration.
4 So essentially the tubes are not held in 5 place securely enough so it allows them to slide or 6 vibrate. SONGS has continued to analyze and develop 7 additional actions to fix and prevent this from happening 8 again. Next slide.
9 Now what I'd like to talk about is the item 10 or the items that the team identified that require 11 additional follow up. However on this 10, we only --
12 we believe that only two are related to the tube-to-tube 13 wear. I am just going to very briefly discuss these 14 items. 15 There's a post trip and transient 16 procedure. SONGS did not conduct a formal review of 17 the reactor trip because they considered a plant trip 18 when they shut down the unit. So we are going to look 19 at the procedure as well as the operator actions to assess 20 if it was appropriate.
21 We are going to evaluate and disposition, 22 look at the numerous Unit 3 loose part monitor alarms.
23 The NRC needs to review how these alarms were evaluated.
24 We do have concerns that the alarms were treated as 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 23 what we call nuisance alarms, versus being evaluated 1 in accordance with procedures.
2 The retainer bar design was not evaluated 3 for vibration impacts. Although this sounds familiar, 4 this wear is not related to the tube-to-tube wear. We 5 are reviewing the design basis of the retainer bars.
6 We are also going to look at the evaluation 7 of and control of the Unit 3 divider plate repair. This 8 by far was the most significant difference between the 9 two units and it has been discounted as a potential cause 10 for the tube-to-tube wear.
11 The bowl of the steam generator that directs 12 the reactor fluid into the tubes as well as the plate 13 that separates the hot and cold reactor coolant had to 14 be cut out, repaired, re-welded and re-tested. Again, 15 we did not identify an issue related to the tube-to-tube 16 wear for this repair.
17 Unit 3 steam generator shipping 18 requirements were changed form what was required as 19 compared to Unit 2. There's nitrogen pressure, dew 20 point, and oxygen contents were not controlled or 21 monitored. These items are supposed to be controlled 22 to minimize corrosion of the internals of the steam 23 generators.
24 Item number 6. Lack of tube bundle support 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 24for the steam generators during shipment. The shipping 1 specification did not initially have a requirement for 2 a tube bundle support, or it have a requirement for tube 3 bundle support, but it was not used during shipment.
4 So again, we are going back to look at that to see how 5 that was dispositioned.
6 We are going to look at the shipping 7 accelerometer data for Unit 3. Steam generator 88, 8 which was one of the generators for Unit 3, had all 9 accelerometers register an excessive force, which could 10 indicate mishandling during the transportation of steam 11 generators. The NRC was not able to determine if this 12 was properly reviewed.
13 We are looking at the 50.59 adequacy. The 14 NRC is continuing to review the adequacy to SONGS 50.59.
15 We did identify a concern with the potential for using 16 a different methodology than what was described in the 17 updated final safety analysis report.
18 SONGS changed their structural analysis 19 method as well as a tube-stress calculation, and we need 20 to do some additional reviews on that to determine if 21 they should have asked for an amendment.
22 The next two follow-up items, number 9 and 23 10, are the ones that the NRC believes are related to 24 the unexpected tube wear. As I discussed previously, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 25 the manufacturing differences, Mitsubishi improved the 1 manufacturing process, which sounds like it should be 2 good. 3 However, they didn't go back and look and 4 see what that would do to the original design dimensions.
5 They didn't go back and compare, should they have 6 reviewed, revised, shrunk the design dimensions. So 7 this resulted in a less rigid tube bundle, which 8 contributed to the vibration issue.
9 And as I discussed before, item number 10, 10 the computer simulation model. Again, the Mitsubishi 11 model underpredicted the behavior of the steam and water 12 in the steam generators.
13 Again, as described earlier, the 14 combination of those two, the higher than predicted steam 15 water flow and the less rigid tube bundle for Unit 3, 16 they vibrated and caused the tube-to-tube wear.
17 The NRC will be conducting additional 18 inspections to review each of these issues. We have 19 been and will be requesting additional information from 20 SONGS as part of our follow-up inspection activities.
21 This completes my discussion of the 22 augmented inspections activities. I'm going to let Tom 23 Blount, turn it back to him. He's going to summarize 24 the key points associated with this inspection. Thank 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 26 you. 1 MR. BLOUNT: Thank you, Greg. So what we'd 2 like you to walk away from this inspection understanding, 3 is the NRC does understand what the mechanistic causes 4 of the tube degradation are. The thermal hydraulic 5 conditions were not accurately predicted during the 6 design phase.
7 However, additional actions, as Greg has 8 pointed out, additional actions are being evaluated and 9 developed by the licensee, and these additional actions 10 will need to be inspected by us to ensure that this 11 condition will not exist in the future.
12 The NRC is not done. We have not reached 13 any conclusion. We have got more inspection to do.
14 We recognize that and we want you to understand that 15 we recognize that. We'll take as much time as necessary 16 to ensure safety, the safety of these facilities, and 17 no decision to this point has been made. Okay?
18 With that, I'd like to ask Pete Dietrich 19 if he'd like to provide his response.
20 MR. DIETRICH: Thank you, Mr. Blount. I'm 21 Pete Dietrich, the Senior Vice President and Chief 22 Nuclear Officer for Southern California Edison.
23 In our comments tonight, we'd like to update 24 you on the actions Southern California Edison has taken 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 27and will take as we work to completely understand the 1 conditions of our steam generators and the effect on 2 San Onofre.
3 I'll make some opening remarks and then Doug 4 Bauder, our site vice president, will provide some 5 comments about the current conditions of the units, the 6 planned response to the tube leak and our learnings, 7 because we are a learning organization. We learn from 8 all things that occur in our facility. But Doug will 9 discuss our learnings in the area of our response.
10 Then Tom Palmisano, the vice president of 11 engineering, will summarize our technical evaluation 12 and the conclusions that we have reached to date. Much 13 work has been done, yet we still have much work to do 14 to fully understand and address what we have learned.
15 And then I will provide some closing remarks.
16 Just to start with, Southern California 17 Edison's overriding interest is the health and safety 18 of the public and our employees. Consequently, both 19 San Onofre units are shut down and will remain shut down 20 until repairs have been made and we and the Nuclear 21 Regulatory Commission are satisfied it is safe to 22 operate. 23 We are disappointed that the situation has 24 occurred and we recognize the impact on our stakeholders, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 28 including customers of Southern California Edison, San 1 Diego Gas and Electric and the City of Riverside. We 2 are also concerned about the concerns that you have, 3 members of the public and also our neighbors.
4 So Southern California Edison understands 5 the significance of the unexpected tube-to-tube wear, 6 and we agree with the facts presented tonight by the 7 Nuclear Regulatory Commission.
8 We appreciate the NRC's insights into this 9 situation and we pledge to continue to work with the 10 NRC to assure any remaining or additional questions are 11 answered promptly.
12 Early on, we recognized the seriousness of 13 the situation. As a result of the complex technical 14 nature of the wear, we recognized that we needed to 15 assemble the very best team to augment our resources 16 and the resources of the steam generator designer and 17 manufacturer, Mitsubishi Heavy Industries.
18 As a result, we have brought together 19 experts in thermal hydraulics and steam generator design 20 from around the world to help us gain an understanding 21 of the causes of this unexpected tube-to-tube wear and 22 potential corrective actions to address it.
23 The experts include such subject matter 24 experts from companies such as AREVA, Westinghouse and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 29B&W Canada. We have used this assembled team, as well 1 as other industry experts and consultants, to review 2 the progress of our work and challenge the thoroughness 3 and adequacy of our conclusions. And we will continue 4 to do so.
5 With that, I'd like to turn it over to Doug 6 to discuss the current status of the units and our 7 response to the tube leak.
8 MR. BAUDER: Thank you, Pete. I would like 9 to cover the current status of the San Onofre units.
10 Unit 2 remains shut down since January the 9th when we 11 started our planned refueling outage, an outage that 12 included a reactor vessel head replacement and planned, 13 full-scope testing of our Unit 2 steam generator tubes.
14 On January 31st, the San Onofre operators 15 shut down Unit 3 in accordance with plant procedures 16 after detection of a very small tube leak on that unit.
17 Their actions demonstrated the right, 18 conservative decision-making and focus on protecting 19 the health and safety of plant personnel and the public.
20 I observed from the Control Room our 21 operators' response, and I was pleased with their calm, 22 deliberate approach to properly quantifying the leak 23 and the execution of our plant procedures to safely shut 24 down the plant.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 30 In fact, in my discussions with the 1 operators after the event, they told me the plant 2 response lined up with their experience and training 3 on our simulator where they frequently train --
4 (Sound system interference) 5 MR. BAUDER: I'm going to switch mics.
6 Everything okay over there? That would be a no.
7 (Off-mic discussion) 8 MR. BAUDER: Thank you. So yes, to catch 9 us back up. In my discussions with the operators 10 following the shut down on January 31st, they confirmed 11 with me the planned response matched what they were 12 trained for and evaluated for in our plant simulator.
13 And that evaluation is frequently done before our 14 operators for steam generator tube leaks.
15 As a learning operation -- organization, 16 we have reviewed our plant equipment, our procedures 17 and our operator training programs as a result of the 18 shut down on January 31st.
19 We have improved our leak detection 20 capability. We have enhanced our operator training 21 programs and built the lessons learned from this event 22 into our plant simulator training activities.
23 We have also reviewed the post-shutdown 24 critique process and we have enhanced the procedures 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 31 that tied the post-shutdown critique process to any plant 1 trip. 2 Also, we have shared this information with 3 the industry. As Pete indicated, we are a learning 4 operation. We are all about learning, building things 5 back into our processes and sharing them with the 6 industry.
7 In conclusion, our operators took prompt, 8 conservative actions to shut down Unit 3, placing the 9 very highest priority on protecting the health and safety 10 of the public.
11 At this point I would like to turn the 12 presentation over to Tom Palmisano to talk through 13 insights and perspectives on open items, as well as 14 Southern California Edison's technical work so far on 15 our steam generators. Tom.
16 MR. PALMISANO: Okay. Thank you, Doug.
17 Can you hear me okay in the back? Great. Thank you.
18 What I would like to do is provide an update on the 19 technical work to date on our investigations, and talk 20 about some of the upcoming actions that we have in place.
21 And as Pete Dietrich has said and the NRC 22 has said, we have more work to do. We realize that.
23 And we're being very deliberate and conservative in our 24 approach to our work.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 32 So first, Mr. Warnick did a good job of 1 giving you an overview of the steam generator's function 2 of the plant design and the steam generator design 3 itself. I just want to point out a couple of things.
4 Tom, if you highlight the steam generator.
5 Two key functions we're talking about tonight. One 6 is the transfer heat from the radioactive primary system 7 to the secondary side to boil water to make steam that 8 ultimately turns the turbine and generates electricity.
9 The other key function, and particularly 10 from a safety standpoint, is the function of the steam 11 generator tubes to prevent radioactive primary water 12 from leaking to the secondary side. So, those are the 13 two key functions we are focused on in this discussion 14 and in our current work. Next slide please.
15 In this slide, a cutaway of the steam 16 generator, we have already explained, or the NRC has 17 already explained the flow path. Just let me reiterate 18 it. 19 The hot radioactive water comes in through 20 what's called the hot leg at the bottom, flows up through 21 the steam generator tubes, around the U-tube bend, the 22 top of the tubes, and down through the remaining straight 23 portion and out the cold leg.
24 The heat from that water is transferred to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 33 the secondary side to boil the water to make the steam 1 that exits the top of the steam generator. Of particular 2 importance tonight is what's labeled the U-bend section.
3 This is where the tube-to-tube wear has occurred that 4 caused the tube leak in one of the tubes, and also caused 5 the damage in the other tubes that caused us to do the 6 in situ pressure test and caused the test failures.
7 So it's the very top of the U-bend that we're 8 going to be talking about where the tube-to-tube wear 9 has occurred. Thank you, Tom. Next slide, please.
10 So, let me kind of summarize the actions 11 to date at this point. Following the Unit 3 shutdown 12 on January 31st, we performed a comprehensive and 13 rigorous inspection of all 19,454 steam generator tubes 14 in the two Unit 3 steam generators. Each steam generator 15 has 9,727 tubes, roughly 10,000 tubes per steam 16 generator. So we did a comprehensive inspection of all 17 of them. 18 We've reviewed these inspection results 19 with industry experts and identified the cause of the 20 tube leak as unexpected tube-to-tube wear. This wear 21 caused one tube to leak and caused the other eight 22 tubes -- there were eight tubes that we talked about 23 -- to fail the in situ pressure testing.
24 Further inspection showed wear on 326 of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 34the these 19,454 tubes. So I'd like you to have that 1 perspective with those numbers. The wear is in a very 2 localized root area of that upper tube bundle we saw 3 on the previous slide, and based on the finding of this 4 unexpected tube-to-tube wear, we elected not to restart 5 Unit 2. Unit 2 was in the process of completing a 6 refueling outage, had already had all of its tubes 7 inspected, and was in satisfactory condition to operate.
8 We elected not to restart Unit 2 at that time.
9 We wanted to make sure, given the unusual 10 nature of this tube-to-tube wear in Unit 3, that we took 11 every opportunity to inspect and test Unit 2 to help 12 us understand what was going on with the Unit 3 steam 13 generator tubes. We felt that was very important.
14 Recognizing the significance of this 15 unexpected tube-to-tube wear, we assembled a team of 16 experts to assist Southern California Edison and 17 Mitsubishi, the steam generator manufacturer.
18 You have heard this discussed by the NRC 19 and by Pete Dietrich, and in a minute, I'll talk more 20 about that panel.
21 To date we have now completed extensive 22 tests and analysis. We have done over 60,000 tests on 23 steam generator tubes in both Units 2 and Unit 3 and 24 have performed significant analysis of the test results 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 35 to understand the cause of the tube-to-tube wear.
1 As has been pointed out by the NRC, it's 2 significant to note there are differences between the 3 two units. Unit 3, which experienced the tube leak, 4 had 326 tubes damaged by this tube-to-tube wear. Unit 5 2 had only two tubes which showed minor indications of 6 tube-to-tube wear, so small it was almost undetectable.
7 It was our rigorous re-testing that identified two tubes 8 that had minor indications.
9 So Unit 2 is in much better condition than 10 Unit 3. The comments that Mr. Werner had about the 11 differences in the manufacturing tolerances between the 12 units explains partially why Unit 2 is in much better 13 condition than Unit 3 is with respect to tube-to-tube 14 wear. 15 Next slide. The expert panel. This is 16 significant. You know, in any outage, we start with 17 our own expertise. We start with the manufacturer, 18 Mitsubishi Heavy Industries.
19 And as we realized the significance and 20 usual nature of this tube-to-tube wear, we stopped and 21 we formed a group of experts to assist us both onsite 22 and off-site and in expert panels.
23 We have brought in Areva, Westinghouse and 24 B&W Canada. All of those firms design, manufacture and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 36test steam generators. They are competitors to 1 Mitsubishi.
2 (Off-mic question) 3 MR. PALMISANO: Babcock & Wilcox, Canada.
4 Yes. B&W, Canada. We brought in MPR Associates, which 5 is a leading problem-solving firm, both in the nuclear 6 and non-nuclear industry, renowned for their ability 7 to deal with difficult, technical issues.
8 We immobilized EPRI, the Electric Power 9 Research Institute. This is the electric utilities 10 industry's research group where we do cutting-edge 11 research across the board in the electric utility 12 industry, including nuclear. This is where we share 13 technical information, and in the nuclear side, we 14 maintain some technical standards that we operate and 15 maintain our plants to, particularly for steam 16 generators.
17 We also brought in other industry personnel 18 from sister utilities with similar steam generators with 19 good expertise to assist us, and as has been mentioned, 20 some recognized academics and consultants who do serious 21 research in thermal hydraulic analysis, vibration 22 analysis, and steam generator testing.
23 So, we have assembled a team, and I think 24 it has been alluded to, this is virtually an unparalleled 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 37effort in the industry. The sharing, the cooperation, 1 the critical nature of this work has been the best I 2 have seen, and I think Mr. Werner's comments have echoed 3 that. 4 Now, the team was established not just to 5 assist us, but to also challenge our work. We wanted 6 to make sure that we put in place not just getting good, 7 solid technical assistance, but a good critical 8 challenge.
9 We used an expert panel board process. The 10 team forms up on site every three to four weeks, and 11 we spend one to two days reviewing the result of our 12 work to date, making presentations, getting critical 13 comments and getting some redirection, if you will, on 14 things that they feel we should investigate more fully.
15 They have turned out to be quite valuable 16 and we are continuing their use through our remaining 17 technical work and our restart decisions as we formulate 18 our final plans.
19 Next slide. So what have we determined in 20 terms of cause? The specific mechanism -- you have heard 21 the NRC discuss this, and I'll use the term -- it's called 22 fluid-elastic instability.
23 Basically, that is causing some of these 24 tubes, these selected tubes, to vibrate excessively to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 38where they are contacting adjacent tubes. That is not 1 the way these steam generators are designed to operate.
2 It's a vibration mechanism that should not be occurring.
3 We see this. This is causing the excessive 4 wear and it's in this limited area of the Unit 3 steam 5 generators. It is caused, this fluid-elastic 6 instability or tube vibration, is caused by high steam 7 flow velocities -- and this has already been alluded 8 to -- very dry steam, in other words, very localized 9 areas where there is very dry steam, very little liquid 10 as the water is boiled to steam, and inadequate tube 11 support structure, that anti-vibration bar structure, 12 in the U-bend region around these tubes that are 13 experiencing wear. The tube support structure is not 14 providing sufficient restraint.
15 So a combination -- high stream flow 16 velocities, very dry steam and the interaction with this 17 tube support structure in the Unit 3 steam generators.
18 Again, we do not see much evidence of this phenomenon 19 in Unit 2 because Unit 2 clearly has a tighter tube 20 support structure than Unit 3 does.
21 Our findings correlate very well with the 22 NRC's comments on the thermal hydraulic analysis. These 23 conditions were not predicted clearly during the design 24 phase to be as severe as they are. We are in agreement 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 39with the NRC's conclusions on that. And also, the 1 differences between Unit 3 and Unit 2, likely due to 2 manufacturing tolerance differences and manufacturing 3 process differences, seem to explain the difference 4 between Unit 2 and Unit 3, and we are in agreement with 5 the NRC's Augmented Inspection Team on those.
6 Now, we have a good understanding of the 7 cause of the tube vibration which causes the tube-to-tube 8 wear. Our expert panel has reviewed this several times.
9 They have challenged us and they are in concurrence 10 with our conclusion as far as what is causing the 11 tube-to-tube wear.
12 Next slide, please. So, the next steps.
13 And again, I'd like to emphasize something you have heard 14 Pete be very clear on and the NRC say, we are taking 15 as much time as necessary to ensure this is understood 16 and that this is properly corrected. So that has been 17 a theme from the start of this investigation.
18 So, we are following up with the Augmented 19 Inspection Team's additional request. Two of their open 20 items clearly are related to the cause. They have 21 legitimate needs for more information on the other open 22 items and our team is supplying that information as it 23 becomes available and working with the inspection team.
24 We are designing and implementing our 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 40 corrective actions to prevent this tube vibration from 1 occurring, based on our understanding of the mechanism.
2 We are developing additional information 3 as stated in the Confirmatory Action Letter which we 4 committed to prior to restart that we know we need to 5 submit, and we are continuing to work to develop 6 intermediate and longer term solutions to this problem.
7 As Pete said, we are disappointed in this 8 and we are working on longer term solutions. And those 9 longer term solutions will require extensive analysis, 10 mock-up and testing prior to being implemented.
11 In summary, we have identified the cause 12 of the unexpected tube-to-tube wear. We are in 13 agreement with the comments as discussed by the NRC 14 tonight. 15 We continue to take a rigorous, deliberate 16 and conservative approach to completing our remaining 17 actions, and we are taking as much time as necessary 18 to insure safety.
19 With that, let me turn it back to Pete 20 Dietrich.
21 MR. DIETRICH: Thank you. By bringing 22 together experts in thermal hydraulics and steam 23 generator design and --
24 (Sound system interference) 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 41 MR. DIETRICH: tests and analysis mentioned 1 by Tom Palmisano, we have determined the cause of the 2 unexpected tube-to-tube wear.
3 We are working on different options and 4 solutions for the future. We have 5 (No audio) 6 MR. BLOUNT: Thank you, Pete. We 7 appreciate those comments. Looking at our path forward, 8 it's important to note that the NRC still has much more 9 information to review. The cause evaluation has been 10 completed by SONGS and they are working on additional 11 actions to prevent the tube-to-tube wear from occurring 12 again. 13 We currently do not know what the final 14 actions will be. So for the NRC to speculate on what 15 is going to occur would not be appropriate. However, 16 I will tell you what we do know.
17 We continue to review information as it 18 becomes available, and as the Augmented Inspection Team 19 continues to review information, we ask SONGS additional 20 questions, and we request additional information, as 21 you have heard.
22 Our inspection will continue until we are 23 satisfied we have sufficient or enough information to 24 make a determination. Based on the Confirmatory Action 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 42Letter, we will have to complete additional inspections 1 once SONGS informs us that they --
2 (No audio) 3 MR. DIETRICH: letter before we will go out 4 and do those inspections.
5 Portions of our AIT team will be called upon 6 to go out and do follow-up inspections on the 10 items 7 that we discussed earlier that were identified as part 8 of this inspection.
9 The NRC does plan to have additional public 10 meetings to keep you informed of our activities. As 11 part of our plans, we will have meetings with SONGS 12 designed to present their readiness plan associated in 13 response to the Confirmatory Action Letter.
14 After we have completed our inspection, we 15 will have another meeting to discuss the results of that 16 inspection. In addition, there are some type of public 17 meeting and press conference that will be held by the 18 senior management, NRC senior management, to discuss 19 any future NRC decision about the acceptability of 20 resumption of power operations. That decision will be 21 based on discussions with both the Region 4 and NRC 22 headquarter senior management.
23 And finally, as part of our normal process, 24 and how the NRC does business, we look back at our 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 43 inspection program and we look to see, are there things 1 out of this event that we should have seen earlier?
2 Are there processes that we should have been engaged 3 in, to help us learn how to get better at what it is 4 that we do? Is there something that we could have been 5 doing do better, or looking at, prior to this event 6 occurring, that would have precluded that event? That 7 is also to help our inspection efforts going forward.
8 So with that, I'd like to turn it over to 9 Elmo Collins for closing remarks. Elmo?
10 MR. COLLINS: Well, thank you, Tom. To 11 conclude the business portion of the meeting, I will 12 say thank you to the residents of California for being 13 here tonight and thank you for listening attentively.
14 I have been quite 15 (No audio) 16 MR. COLLINS: how polite and how patient 17 you have been as we move through a lot of information 18 tonight. So I thank you for that.
19 I want to thank this Augmented Inspection 20 Team that we have talked about. A lot of hours of work 21 has gone on of people with high expertise. And so I 22 am glad we were able to hear the results of their 23 inspection and I hope it was informative for you.
24 I want to thank Edison, Mr. Dietrich, for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 44 your presentation and response to the information you 1 shared with us. And lastly, I probably would be remiss, 2 if we didn't all express our appreciation to the 3 representatives from the Orange County Sheriff's Office 4 who are here looking out after our safety. So give them 5 a round of applause.
6 (Applause) 7 MR. COLLINS: I know --
8 (No audio) 9 FACILITATOR DANIEL: Thank you Elmo. you, 10 Elmo. Thank you Southern California Edison and NRC.
11 Thank you audience, ladies and gentlemen, for being so 12 attentive, as Elmo --
13 (No audio) 14 FACILITATOR DANIEL: We are going to take 15 a -- 16 (No audio) 17 FACILITATOR DANIEL: We are going to start 18 back at 7:20 sharp with a question and comment period.
19 In the meantime, Mr. Collins is going to be doing a 20 media interview, I believe --
21 (No audio) 22 FACILITATOR DANIEL: Enjoy the break. We 23 will see you at 7:20. Thank you.
24 (Whereupon, at 11:17 a.m., DVD 1 ended) 25