ML030590410
| ML030590410 | |
| Person / Time | |
|---|---|
| Site: | Boiling Water Reactor Owners Group |
| Issue date: | 03/25/2003 |
| From: | Wang A NRC/NRR/DLPM/LPD4 |
| To: | Stephen Dembek NRC/NRR/DLPM/LPD4 |
| Wang A, NRR/DLPM, 415-1445 | |
| References | |
| NEDO-33095 | |
| Download: ML030590410 (6) | |
Text
March 25, 2003 MEMORANDUM TO: Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM:
Alan B. Wang, Project Manager, Section 2
/RA/
Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF MEETING WITH THE BOILING WATER REACTOR OWNERS GROUP (BWROG) CONCERNING THE DEVELOPMENT OF A NEW REACTOR CORE STABILITY LIMIT On February 20, 2003, an open meeting was held between the BWROG and the NRC staff to discuss the BWROG efforts to develop a new reactor core stability limit. The new stability limit will provide the best basis for the final resolution of this issue with the class of boiling water reactors referred to as the "detect and suppress" (D&S) plants. In June 2001, GE Nuclear Energy reported that generic delta versus initial oscillation magnitude (DIVOM) curves could be non-conservative. This resulted in a 10 CFR Part 21 notification. Individual plants implemented corrective actions as a result and the BWROG D&S Committee was reformed to develop a new generic DIVOM correlation.
The BWROG again stressed that the solution must satisfy all regulatory requirements, applicable fuel design limits for stability and allow return to operation immediately after a stability event. In addition, the BWROG wanted a robust solution that would be applicable to all BWR fuel vendors, and compatible with existing stability based hardware/software. The committee considered several alternatives and selected an approach that evaluates the actual response of the fuel pellets, cladding, and associated structural materials to instability events.
Instead of using the critical power ratio as a surrogate measure for cladding performance, they would use the TRACG calculations to define the reactor power and fluid conditions, and apply those values as inputs to fuel thermal-mechanical analyses to show that specified acceptable fuel design limits (SAFDLs) would not be exceeded. The evaluations for each fuel type would be performed by each fuel vendor, using the thermal-hydraulic inputs from TRACG. The new stability limit would no longer be based on protection of the minimum critical power ratio.
The BWROG has developed NEDO-33095, "Licensing Application Framework for BWROG Stability Limit Analysis." This document would provide a flow chart for the scope, objective, licensing requirements and all the documentation to support a new stability limit analysis. The BWROG presented detailed information on how they thought this process could proceed. The BWROG milestones were to have the confirmation analysis completed by the third quarter of 2003 and the engineering analysis by the fourth quarter of 2004. The topical report would be provided to the staff by the first quarter of 2005 with the anticipation that the NRC review would take one year.
S. Dembek Mr. Wermiel asked the industry to think about how the NRC might incorporate safety significance thinking into this program reducing NRC (and industry) resources. In particular, he specifically suggested that if the NRC is aware of and has confidence in the BWROG methods, then the review would require fewer resources to come to agreement on an acceptable approach. It could be possible that the NRC could perform a limited scope review of BWROG reports and the industry could implement the new safety limit on its own.
NRC approval would be conveyed through a technical specification change that requires NRC review and approval. That review and approval would be supported by the BWROG documentation. However, NRCs approval would be largely based on the safety significance of the technical specification change.
The NRC asked what the BWROG saw as the impetus to pursue the new safety limit approach.
The BWROG responded that they had equipment installed, but in various stages of operability and arming. Use of this equipment would be advantageous. Also, the industry saw the use of interim corrective actions as limiting operationally, and saw the need for NRC-required approval for technical specifications relative to their detect and suppress equipment.
It was also pointed out that this possible safety significance approach applied only to the current stability issue, not to MELLLA+. However, in general, Mr. Wermiel suggested that the use of resources should be commensurate with the safety significance of the issue.
The staff thanked the BWROG for the presentation and encouraged an update on developments in the next several months. The staff expressed that this would be an ambitious undertaking and there are a number of technical issues that need to be addressed for which there is limited experimental evidence. This meeting was informational. No regulatory decisions were made. The BWROG was encouraged by the staffs suggestions and proposed to meet in 4 to 6 weeks. The meeting handouts (Attachments 1, 2, and 3) can be found in ADAMS under Accession Nos. ML030620110, ML030620118, and ML030620120. The attendance list is attached.
Project No. 691
Attachment:
Meeting Attendees cc w/att: See next page
ML030590410 Attachment No. 3: ML030620120 NRC-001 OFFICE PDIV-2/PM SRXB/BC PDIV-2/LA PDIV-2/SC NAME AWang JWermiel EPeyton SDembek DATE 3/20/03 3/21/03 3/20/03 3/24/03 DOCUMENT NAME: G:\\PDIV-2\\bwrog\\Mtg Summary BWROG Stability220.wpd
MEETING WITH THE BOILING WATER REACTORS OWNERS GROUP DEVELOPMENT OF A NEW REACTOR CORE STABILITY LIMIT FEBRUARY 20, 2003 GE NUCLEAR ENERGY J. Andersen R. Hill D. Newkirk I. Nir C. Heck WESTINGHOUSE ELECTRIC COMPANY W. Harris FRAMATOME-ANP D. Pruitt OTHER J. A. Gray, Entergy M. Crawthers, PPL Susquehanna K. Putnam, NMC M. May, Exelon S. Bier, PSE&G NRC J. Wermiel R. Caruso A. Wang S. Lu G. Thomas Z. Abdullahi R. Guzman T. Huang H. Scott
BWR Owners Group Project No. 691 cc:
Mr. Kenneth Putnam, Vice Chairman BWR Owners Group Nuclear Management Company Duane Arnold Energy Center 3277 DAEC Rd.
Palo, IA 52324 Mr. Lesley A. England Reactor Response Group Chairman BWR Owners Group ENTERGY M-ECH-414 P.O. Box 31995 Jackson, MS 39286-1995 Mr. H. Lewis Sumner Southern Nuclear Company 40 Inverness Center Parkway PO Box 1295 Birmingham, AL 35242 Mr. Carl D. Terry Vice President, Nuclear Engineering Nine Mile Point - Station OPS Bldg/2nd Floor PO Box 63 Lycoming, NY 13093 Mr. Thomas G. Hurst GE Nuclear Energy M/C 782 175 Curtner Avenue San Jose, CA 95125 Mr. Thomas A. Green GE Nuclear Energy M/C 782 175 Curtner Avenue San Jose, CA 95125 Mr. James Meister Exelon Cornerstone II at Cantera 4300 Winfield Road Warrenville, IL 60555 Mr. William A. Eaton ENTERGY Grand Gulf Nuclear Station P.O. Box 756 Port Gibson, MS 39150 Mr. Mark Reddeman Vice President Engineering Point Beach Nuclear Plant 6610 Nuclear Road Two Rivers, WI 54241 Mr. Richard Libra DTE Energy Fermi 2 M/C 280 OBA 6400 North Dixie Highway Newport, MI 48166 Mr. James F. Klapproth GE Nuclear Energy M/C 706 175 Curtner Avenue San Jose, CA 95125 Mr. J. A. Gray, Jr., Chairman BWR Owners Group Entergy Nuclear Northeast 440 Hamilton Avenue Mail Stop 12C White Plains, NY 10601-5029