Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION Title: Advisory Committee on Reactor Safeguards Thermal Hydraulics Phenomena & Reliability and PRA Joint Subcommittee Docket Number: N/A Location: Rockville, Maryland Date: September 03, 2014 Work Order No.: NRC-1046 Pages 1-586 NEAL R. GROSS AND CO., INC. Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W. Washington, D.C. 20005 (202) 234-4433 1 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION + + + + + ADVISORY COMMITTEE ON REACTOR SAFEGUARDS (ACRS) + + + + + THERMAL-HYDRAULIC PHENOMENA SUBCOMMITTEE AND RELIABILITY AND PRA SUBCOMMITTEE + + + + + WEDNESDAY SEPTEMBER 03, 2014 + + + + + ROCKVILLE, MARYLAND + + + + + The Subcommittee met at the Nuclear Regulatory Commission, Two White Flint North, Room T2B1, 11545 Rockville Pike, at 8:30 a.m., SANJOY BANERJEE, Chairman, presiding. COMMITTEE MEMBERS: SANJOY BANERJEE, Chairman DENNIS C. BLEY, Member MICHAEL L. CORRADINI, Member NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 2 HAROLD B. RAY, Member JOY REMPE, Member STEPHEN P. SCHULTZ, Member JOHN W. STETKAR, Member ACRS CONSULTANT: GRAHAM WALLIS DESIGNATED FEDERAL OFFICIAL: MARK BANKS NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 3 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 4 T-A-B-L-E O-F C-O-N-T-E-N-T-S PAGE Opening Remarks Sanjoy Banerjee, ACRS........................5 NRC Staff Introduction Mike Markley, NRR/DORL.......................7 Introduction/Review Status Balwant Singal, NRR/DORL.....................8 Tie between STP Pilot Program and the 50.46(c) Rule Tara Inverso, NRR/DPR.......................28 South Texas Project: Introduction Mike Murray, STP......................44 Overview of Progress Since Last ACRS Meeting Ernie Kee, STP........................66 General Overview of PRA Process Flow Ernie Kee, STP........................76 Thermal-Hydraulics Analyses Rodolfo Vaghetto, Texas A&M..........128 CASA Grande Interface with PRA David Johnson, ABS Consulting ...... 182 LOCA Size/Frequency Bruce Letellier, Alion ............. 236 In-vessel effects Ernie Kee, STP ..................... 267 Bruce Letellier, Alion Treatment of Chemical Effects (including relevant testing) - L* Kerry Howe, University of .......... 285 New Mexico Janet Leavitt, Alion Science and Technology NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 5 T-A-B-L-E O-F C-O-N-T-E-N-T-S PAGE Head loss (including relevant testing - VISTA Bruce Letellier, Alion ............. 300 Specific examples (including debris generation and transport and coatings) - comparison of results for 2 failures and 2 successes Bruce Letellier, Alion...............347 Dominic Munoz Public Comment.............................421 Subcommittee Discussion....................422 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 6 P-R-O-C-E-E-D-I-N-G-S (8:31 a.m.) CHAIRMAN BANERJEE: Good morning. This meeting will now come to order. This is a Joint Subcommittee meeting of the Advisory Committee on Reactor Safeguards, Subcommittees on Thermal-Hydraulics Phenomena and Reliability and PRA. I am Sanjoy Banerjee, Chairman of the Thermal-Hydraulics Phenomena Subcommittee, and on my left is John Stetkar, Chairman of the PRA and Reliability Subcommittee. ACRS Members in attendance are Steve Schultz, Harold Ray, Dennis Bley, John Stetkar, of course, and Joy Rempe. Mike Corradini was here but -- He's coming back in. Okay. Our ACRS Consultant today, the former ACRS Chairman, is Dr. Graham Wallis and Mark Banks of the staff is the Designated Federal Official for this meeting. So the purpose of today's meeting is for the NRC staff and representatives from the South Texas Project Electricity Generating Station to discuss the South Texas Project's risk-informed approach to resolving Generic Safety Issue 191. Generic Safety NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 7 Issue or GSI-191 is titled, "Assessment of Debris Accumulation on PWR Sump Performance." The Joint Subcommittee will gather information, analyze relevant issues and facts and formulate proposed positions and actions as appropriate for deliberation by the full Committee. The rules for participation in today's meeting were announced as part of the notice of this meeting previously published in the Federal Register on August 19th, 2014. The meeting will be open to public attendance with the exception of any portions that may be closed to protect information that is proprietary pursuant to 5 U.S.C. 522(b)(c)(4). We have received no written comments or requests for time to make oral statements. A transcript of today's meeting is being kept and will be made available as stated in the Federal Register Notice. Therefore, we request that meeting participants use the microphones located throughout the meeting room when addressing the Subcommittee. Participants should first identify themselves and speak with sufficient clarity and volume so they can be readily heard. NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 8 A telephone bridge line has been established for this meeting. To preclude interruption of this meeting, please mute your individual telephones and lines during presentations and Subcommittee discussion. I ask that you please silence all cell phones. We will now proceed with the meeting and I'll call on Mike Markley, Acting Deputy Director of NRR's Division of Operating Reactor Licensing, to make introductory remarks. Thank you. Mike. MR. MARKLEY: I'm Mike Markley. I'm the, again, Acting Deputy Director for Division of Operating Reactor Licensing and it's a great pleasure for me to come back here. I actually worked for the ACRS for six years so, Dr. Wallis, it's good to see you again. Much credit is to be given to South Texas for the work they've done here. They've done a lot to advance the technology for the phenomenology of strainer blockage as well as the modeling of risk. We spent a tremendous amount of time, I think we're up to about 4,800 hours of review time on this particular review and that doesn't include the pre-licensing time that we spent about 1,800 hours of review. So it's a lot of effort that both the licensee NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 9 and the NRC staff have put into this. Not to dilly-dally we turn it over and begin the presentation. Thank you. MR. SINGAL: My name is Balwant Singal. I am the Senior Project Manager with the Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation. Presently I'm the PM for South Texas Project also and the purpose of my presentation is just to give you a short overview of the status of the submittal under review by the NRC staff. Just a little background slide where SECY-12-093 staff provided recommendations and there are three options and options are listed here but STP decided to pursue Option Number 2, and Option Number 2, it include the risk-informed approach so STP decided to be the pilot plant and pursue the risk-informed approach for resolving the GSI-191 issue. CHAIRMAN BANERJEE: Just before you go I have a question. MR. SINGAL: Sure. CHAIRMAN BANERJEE: Within Option 2 there are sort of two sub-options, right? MR. SINGAL: Option 2A and 2B. NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 10 CHAIRMAN BANERJEE: 2A and 2B. And they chose this risk-informed approach which is one of the sub-options. MR. SINGAL: Yes. CHAIRMAN BANERJEE: Do you have any views as to, and we may ask the Applicant as well, why they chose to do it this way? MR. SINGAL: I think STP has an issue with a lot of fibrous insulation in the plant and they have, like they have to do quite a bit of modification and that's very expensive so they're trying to see if they can, by using the risk-informed approach, if they can eliminate the need for tons of modifications. CHAIRMAN BANERJEE: Okay, so we'll repeat that question later. Thank you. MR. SINGAL: We already kind of went through that. And then before we actually got back the submittal we had, 2011 we started with the pre-licensing actions and we had a total of -- DR. WALLIS: Let me ask you something, though, about this risk-informed approach. It seems to me that the risk-informed approach is a way of avoiding the large break because if you take the large break probability distribution it doesn't happen and that's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W. (202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433 11 the problem. So does the Commission know that that's really what's involved? MR. SMITH: This is Steve Smith of the staff. I think that what we're trying to do, and it might be better for somebody from the PRA guys to answer this, but we are trying to ensure that South Texas's submittal meets the Commission guidelines for -- DR. WALLIS: Yes, I just wondered if the Commission's said any more than just risk-informed.