ML043070054
| ML043070054 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/15/2004 |
| From: | Nerses V NRC/NRR/DLPM/LPD1 |
| To: | Christian D Dominion Nuclear Connecticut |
| Nerses V, NRR//DLPM, 415-1484 | |
| References | |
| TAC MC03747 | |
| Download: ML043070054 (4) | |
Text
November 15, 2004 Mr. David A. Christian Senior Vice President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.
Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION, REGARDING MILLSTONE POWER STATION, UNIT NO. 2, FIVE-YEAR EXTENSION OF TYPE A TEST INTERVAL (TAC NO. MC3747)
Dear Mr. Christian:
By letter dated July 6, 2004, as supplemented by letter dated September 21, 2004, you submitted a proposed risk informed technical specification change five-year extension of Type A test interval.
The Nuclear Regulatory Commission staff reviewed the information you provided and determined that additional information is required in order to complete the evaluation. The additional information requested is attached. If you have any questions, please contact me at (301) 415-1484.
Sincerely,
/RA/
Victor Nerses, Senior Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-336
Enclosure:
As stated cc w/encl: See next page
Millstone Power Station, Unit No. 2 cc:
Lillian M. Cuoco, Esquire Senior Counsel Dominion Resources Services, Inc.
Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 Edward L. Wilds, Jr., Ph.D.
Director, Division of Radiation Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 First Selectmen Town of Waterford 15 Rope Ferry Road Waterford, CT 06385 Charles Brinkman, Director Washington Operations Nuclear Services Westinghouse Electric Company 12300 Twinbrook Pkwy, Suite 330 Rockville, MD 20852 Senior Resident Inspector Millstone Power Station c/o U.S. Nuclear Regulatory Commission P.O. Box 513 Niantic, CT 06357 Mr. J. Alan Price Site Vice President Dominion Nuclear Connecticut, Inc.
Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 Mr. John Markowicz Co-Chair Nuclear Energy Advisory Council 9 Susan Terrace Waterford, CT 06385 Mr. Evan W. Woollacott Co-Chair Nuclear Energy Advisory Council 128 Terry's Plain Road Simsbury, CT 06070 Ms. Nancy Burton 147 Cross Highway Redding Ridge, CT 00870 Mr. Chris L. Funderburk Director, Nuclear Licensing and Operations Support Dominion Resources Services, Inc.
Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711 Mr. David W. Dodson Licensing Supervisor Dominion Nuclear Connecticut, Inc.
Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385
ML043070054 OFFICE PDI-2/PM PDI-2/LA SPSB/SC PDI-2/SC(A)
NAME VNerses CRaynor MRubin DCollins DATE 11/15/04 11/10/04 10/15/04 11/15/04
Enclosure REQUEST FOR ADDITIONAL INFORMATION RELATED TO DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION, UNIT NO. 2 FIVE-YEAR EXTENSION OF TYPE A TEST INTERVAL DOCKET NO. 50-336 By letter dated July 6, 2004, as supplemented by letter dated September 21, 2004, Dominion Nuclear Connecticut, Inc. submitted a proposed risk informed technical specification change five-year extension of Type A test interval. The Nuclear Regulatory Commission (NRC) staff reviewed the information provided and determined that the following additional information is required in order to complete the evaluation.
1.
The risk assessment methodology used to support the integrated leak rate test (ILRT) interval extension for Millstone Power Station, Unit No. 2 (MP2) is based on a methodology developed by the Electric Power Research Institute (EPRI) in 1994. A revision to this methodology was developed for the Nuclear Energy Institute (NEI) by EPRI in 2001, and corrected/improved the original methodology in several areas. Based on an NRC staff assessment, the revised methodology (referred to as the NEI Interim Guidance) would indicate larger risk impacts (e.g., large early release frequency (LERF)) for the ILRT interval extension than the original. In view of the non-conservative nature of the original EPRI methodology, please provide a reassessment of the risk impacts of the requested change for MP2 based on the NEI Interim Guidance. In reporting risk results (for person-rem, LERF, and conditional containment failure probability), include results corresponding to a change in test frequency from 3 tests in 10 years to 1 test in 15 years.
2.
Table 3 of Attachment 2 of your submittal, provides the estimated population dose for each accident class as well as the total population dose summed over all accident classes. The population doses assigned to Class 7 and 8 are substantially higher than values reported for similar release categories in the severe accident mitigation alternative (SAMA) analysis submitted in support of the MP2 license renewal.
Specifically, for early and late containment failures (Class 7), Table 3 indicates a dose of 1.9E6 person-rem, whereas Table F.1-4 of the SAMA analysis indicates a maximum dose of 7.04E5 person-rem. For containment bypass (Class 8), Table 3 indicates a dose of 4.96E6 person-rem, whereas Table F.1-4 of the SAMA analysis indicates a maximum dose of 3.9E6 person-rem. The total population dose in Table 3 (123 person-rem per year) is also substantially higher than that in the SAMA analysis (17.4 person-rem per year). Use of the higher dose values leads to an under-estimate of the percent increase in the population dose resulting from the ILRT interval extension.
Please reconcile the population dose values with those in the SAMA analysis, and provide a reassessment of the impact of the ILRT interval extension on population dose based on appropriate population dose values.