Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION Title: Advisory Committee on Reactor Safeguards Thermal-Hydraulic Phenomena Subcommittee Docket Number: (not applicable) Location: Rockville, Maryland Date: Tuesday, December 5, 2006 Work Order No.: NRC-1346 Pages 1-424 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 UNITED STATES OF AMERICA 2 NUCLEAR REGULATORY COMMISSION 3 + + + + + 4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS (ACRS) 5 + + + + + 6 SUBCOMMITTEE ON THERMAL-HYDRAULIC PHENOMENA 7 + + + + + 8 TUESDAY, 9 DECEMBER 5, 2006 10 + + + + + 11 The meeting was convened in Room T-2B3 of Two White 12 Flint North, 11545 Rockville Pike, Rockville, 13 Maryland, at 8:30 a.m., Dr. Sanjoy Banerjee, Chairman, 14 presiding. 15 MEMBERS PRESENT: 16 SANJOY BANNERJEE Chairman 17 SAID ABDEL-KHALIK ACRS Member 18 THOMAS KRESS ACRS Member 19 JOHN D. SIEBER ACRS Member 20 GRAHAM B. WALLIS ACRS Member 21 22 23 ACRS STAFF PRESENT: 24 RALPH CARUSO 25 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 1 ALSO PRESENT: 2 STEPHEN BAJORK 3 BUTCH BURTON 4 JOSEPH KELLY 5 JOHN MAHAFFY 6 MARINO di MARZO 7 CHARLES MURRAY 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 (202) 234-4433 3 1 C-O-N-T-E-X-T 2 AGENDA ITEM PAGE 3 Introduction .................. 5 4 Opening Remarks ................. 6 5 Overview of TRACE Development .......... 6 6 TRACE Model Revisions ..............88 7 Assessment Results .............. 203 8 Trace Momentum Equation ............ 265 9 Anonymous Letter ............... 327 10 PI Group Ranging ............... 374 11 Adjourn 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 (202) 234-4433 4 1 P-R-O-C-E-E-D-I-N-G-S 2 8:31 a.m. 3 CHAIRMAN BANNERJEE: The meeting will now 4 come to order. This is a meeting of the Advisory 5 Committee on Reactor Safeguards, Subcommittee on 6 Thermal Hydraulic Phenomena. I am Sanjoy Banerjee, 7 Chairman of the Subcommittee. The subcommittee 8 members in attendance are Tom Kress, Graham Wallis, 9 Michael Corradini who seems to be absent and Jack 10 Sieber. Said Abdel-Khalik is participating via video 11 conference for this meeting. 12 The purpose of this meeting is to review 13 the continuing development of the TRACE thermal 14 hydraulic computer code. The subcommittee will hear 15 presentations by and hold discussions with 16 representatives of the NRC staff, the contractors, 17 regarding these matters. 18 The subcommittee will gather information, 19 analyze relevant issues and facts and formulate 20 proposed positions and actions as appropriate for 21 deliberation by the full committee. Ralph Caruso is 22 the designated federal official for this meeting. 23 The rules for participation in today's 24 meeting have been announced as part of the notice of 25 this meeting previously published in the Federal 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 1 Register on November 15th, 2006. A transcript of the 2 meeting is being kept and will be made available as 3 stated in the Federal Register notice. It is 4 requested that speakers first identify themselves and 5 speak with sufficient clarity and volume so that they 6 can be readily heard. 7 We have no received any requests from 8 members of the public to make oral statements or 9 written comments. So I think with that, we can now 10 proceed with the meeting and I'll call upon Mr. 11 Bajorek of the NRC staff to begin. 12 DR. BAJOREK: Good morning, Dr. Bannerjee. 13 I'm going to start off in a minute. My name is Steve 14 Bajorek from the Office of Research, but in order to 15 give just a brief introduction, Butch Burton, our 16 Branch Chief, is going to speak for just a few 17 moments. 18 MR. BURTON: Thanks, Steve. As Steve 19 mentioned, my name is Butch Burton. I serve as the 20 Chief of the Code Development Branch in the Office of 21 Research. Some of you may remember me from awhile 22 back from my license renewal work. Others I haven't 23 had the opportunity to meet but I hope to meet you 24 shortly. 25 I wanted to talk briefly about meeting 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 1 objectives and some introductory remarks. What we 2 hope to accomplish today is to bring the subcommittee 3 up to speed on some of the recent activities that the 4 staff's been engaged in with regard to the development 5 of the TRACE code and we'll also touch briefly on the 6 graphical user interface work that we've done with our 7 SNAP code. 8 Steve Bajorek and Joe Kelly will provide 9 the lion's share of the information in those areas. 10 Joe will also be talking about some of the 11 developmental work we've done with regard to some of 12 the constitutive models. Throughout the presentation, 13 one of the things that we'd like to get from you all 14 as subcommittee members is to identify topics for 15 future meetings. We recognize that this is going to 16 really provide sort of an overview and status of our 17 work, but as we go through, it would be very helpful 18 to us if you would identify areas of particular 19 interest or concern that you'd like to have a more 20 fuller discussion on in the future. 21 Also, as you're aware, it's been almost a 22 year now that you received the latest of several 23 issues and concerns that were submitted to you all 24 anonymously. We responded to you all last March that 25 we would be addressing those and this is really our 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 1 first opportunity to do that. And in order to do 2 that, we've asked Professor Mahaffy from Penn State 3 University to come and join us and he'll be giving a 4 presentation responding to some of those issues and 5 concerns. Also as we were preparing for this 6 briefing, we were informed that there were some issues 7 with regard to the momentum equations and their 8 development and application. So Dr. Wallace, we hope 9 to address some of those issues for you today also. 10 And again, Professor Mahaffy will be discussing those. 11 Finally, we'll also be providing a 12 discussion to you with regard to some of the scaling 13 distortion issues that have been of issue and concern 14 recently. A little bit of history; as many of you 15 know, TRACE development really began in the mid to 16 late `90s. The driver for that was at the time we had 17 several thermal hydraulic codes, TRAC-P, TRAC-B, 18 RELAP-5, all of which were being developed, assessed, 19 maintained, in parallel as well as a neutronics code 20 and in the mid-`90s there was a decision that for 21 efficiency sake, we would try to consolidate those. 22 The work has progressed more slowly than we would have 23 liked and there have been a number of reasons for 24 that, some of which is that some of these legacy codes 25 had challenges that we had not anticipated and that we 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 1 had to deal with. 2 We have a relatively limited staff to 3 address some of the developmental issues. In fact, in 4 terms of the actual staff, lead staff on this, we 5 really have five people. In addition to Steve 6 Bajorek, who provides overall technical direction, we 7 have Joe Kelly, who is basically the lead in model 8 development; Joe Stoddermeyer, who is involved with 9 deck development and numerics; Chris Murray who is 10 involved with configuration control and has developed 11 a number of tools to help with efficiencies, and 12 Chester Gingrich, who is our lead with the graphical 13 user interface work. 14 In addition to those leads, we had a very 15 limited support staff of junior engineers who have 16 really been coming on very nicely and very recently, 17 and when I say recently, within the last couple of 18 months, we've brought on new staff, primarily folks 19 out of school but some with some experience and we're 20 hoping to develop them over the next couple of years 21 to join our staff which will allow for much more in- 22 house work, much more of the work to be done in-house 23 and with the associated reduction in resource 24 commitments.