ML061660328
| ML061660328 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee  |
| Issue date: | 06/09/2006 |
| From: | James Shea Plant Licensing Branch III-2 |
| To: | Kansler M Entergy Nuclear Operations |
| SHea J, NRR/DLPM, 415-1388 | |
| References | |
| TAC MC5488 | |
| Download: ML061660328 (6) | |
Text
June 9, 2006 Mr. Michael R. Kansler President Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGES TO REVISE CONTROL ROD OPERABILITY, SCRAM TIME AND CONTROL ROD ACCUMULATOR SURVEILLANCE TESTING (TAC NO. MC5488)
Dear Mr. Kansler:
By letter dated December 15, 2004, as supplemented by letter on December 12, 2005, Entergy Nuclear Operations, Inc. submitted an amendment request to revise the Vermont Yankee Nuclear Power Station control rod operability, scram time and control rod accumulator technical specification surveillance testing requirements.
The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). A response to these RAIs is requested to be provided within 30 days.
Sincerely,
/RA/
James J. Shea, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-271
Enclosure:
As stated cc w/encl: See next page
June 9, 2006 Mr. Michael R. Kansler President Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGES TO REVISE CONTROL ROD OPERABILITY, SCRAM TIME AND CONTROL ROD ACCUMULATOR SURVEILLANCE TESTING (TAC NO. MC5488)
Dear Mr. Kansler:
By letter dated December 15, 2004, as supplemented by letter on December 12, 2005, Entergy Nuclear Operations, Inc. submitted an amendment request to revise the Vermont Yankee Nuclear Power Station control rod operability, scram time and control rod accumulator technical specification surveillance testing requirements.
The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). A response to these RAIs is requested to be provided within 30 days.
Sincerely,
/RA/
James J. Shea, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-271
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsNrrDORLLpl1-1 RidsOgcRP VKlein LPLI-1 R/F RidsNrrLASLittle RidsAcrsAcnwMailCenter RidsNrrPMJShea RidsNrrDORLDpr RidsRgn1MailCenter Accession Number: ML061660328 OFFICE LPL1-1/PM LPL1-1/LA SNPB/BC LPL1-1/BC NAME JShea SLittle FAkstulewicz RLaufer DATE 6/07/06 6/09/06 6/09/06 6/09/06 Official Record Copy
SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGES TO REVISE CONTROL ROD OPERABILITY, SCRAM TIME AND CONTROL ROD ACCUMULATOR SURVEILLANCE TESTING ENTERGY NUCLEAR OPERATIONS, INC.
VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271 By letter dated December 15, 2004, as supplemented by letter on December 12, 2005, Entergy Nuclear Operations, Inc. submitted an amendment request to revise the Vermont Yankee Nuclear Power Station (VY) control rod operability, scram time and control rod accumulator technical specification surveillance testing requirements.
The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review.
- 1) Based upon your response to RAI #2 (Reference 2), the staff infers that you are operating under Option B1 but that if during scram time testing any control rods are declared slow or if the cycle specific analytical scram reactivity curve requires faster scram times than whats in TS 3.3.C you will impose the use of higher MCPR limits (Option A)2. Please verify if this is correct. Otherwise, please address the following:
Previously your TS required that the average of all control rods scrammed in accordance with your analytical scram reactivity curve. In your proposed amendment, you propose an allowance for up to 6 slow control rods whose scram times would exceed the requirements of the curve. In your justification for this change you state that the analytical scram reactivity curve will be met if some rods scram slower than the limit as long as some rods scram faster than the limit. The allowable scram times in TS 3.3.C (Table 4.3.C-1) are the same as your analytical scram reactivity curve (provided in response to RAI #2 in Reference 2) with the exception of the scram time until control rods reach notch position 46 which is 0.017 seconds faster than the analytical scram reactivity curve. However the overall scram time (3.419 seconds) is the same as the 1
In Section 4.3.1.2.6 MCPR Uncertainty Considerations GESTAR-II gives 2 options for adjusting the CPR value for all rapid pressurization AOOs such that a 95/95 CPR/ICPR licensing basis is calculated. In regard to Option A, GESTAR-II states: Plants that do not demonstrate compliance with the statistically evaluated scram times must operate using a higher [MCPR] limit that does not take credit for these scram times. In regard to Option B, GESTAR-II states: the generic basis utilized adjustment factors that are dependent on plant and event type and since both the GENESIS and GEMINI adjustment factors take credit for conservatism in the scram speed assumed for the transient analysis, each plant operating under Option B must demonstrate that their actual scram speeds are within the distribution assumed in the derivation of the adjustment factors.
2 In response to RAI #2 you state that as specified in [GESTAR-II], an evaluation is performed for any slow rod (i.e., control rod that does not meet the TS scram time). For rods that do not meet the TS scram times, an adjustment () to the Operating Limit Minimum Critical Power Ratio (MCPR) (Safety Limit + AOO CPR from analysis) is determined as specified in the VY cycle specific Core Operating Limits Report.
analytical scram reactivity curve. In your justification (Page 5 of Enclosure 3 of Reference 1) you state that to account for single failures and slow scramming control rods, the scram times specified in Table 4.3.C-1 are faster than those assumed in the design basis analysis and that the scram times have a margin that allows up to approximately 7% of the control rods to have scram times exceeding the s pecified limits.
- a. Please explain how control rods scramming 0.017 seconds faster until notch 46 can account for the scram reactivity worth of up to six control rods which can be allowed to scram up to 3.581 seconds slower at a fully withdrawn position?
- b. You state in response to RAI #2 that the scram reactivity curve used in the AOO analysis is cycle specific. What happens if during a subsequent cycle the scram reactivity curve requires scram times faster than those specified in the TS? How is the NRC staff assured that Entergy will amend the VY TS to coincide with the scram reactivity curve used in each cycle specific AOO analysis?
References
- 1. Letter from J.K. Thayer (Entergy/Vermont Yankee) to the U.S. Nuclear Regulatory Commission Technical Specification Proposed Change No. 266; Revision to Control Rod Operability, Scram Time Testing and Control Rod Accumulators. December 15, 2004
- 2. Letter from J.K. Thayer (Entergy/Vermont Yankee) to the U.S. Nuclear Regulatory Commission Technical Specification Proposed Change No. 266; Revision to Control Rod Operability, Scram Time Testing and Control Rod Accumulators - Response to Request for Additional Information. December 12, 2005
Vermont Yankee Nuclear Power Station cc:
Regional Administrator, Region I Ms. Carla A. White, RRPT, CHP U. S. Nuclear Regulatory Commission Radiological Health 475 Allendale Road Vermont Department of Health King of Prussia, PA 19406-1415 P.O. Box 70, Drawer #43 108 Cherry Street Mr. David R. Lewis Burlington, VT 05402-0070 Pillsbury, Winthrop, Shaw, Pittman, LLP 2300 N Street, N.W. Mr. James M. DeVincentis Washington, DC 20037-1128 Manager, Licensing Vermont Yankee Nuclear Power Station Mr. David OBrien, Commissioner P.O. Box 0500 Vermont Department of Public Service 185 Old Ferry Road 112 State Street Brattleboro, VT 05302-0500 Montpelier, VT 05620-2601 Resident Inspector Mr. James Volz, Chairman Vermont Yankee Nuclear Power Station Public Service Board U. S. Nuclear Regulatory Commission State of Vermont P.O. Box 176 112 State Street Vernon, VT 05354 Montpelier, VT 05620-2701 Director, Massachusetts Emergency Chairman, Board of Selectmen Management Agency Town of Vernon ATTN: James Muckerheide P.O. Box 116 400 Worcester Rd.
Vernon, VT 05354-0116 Framingham, MA 01702-5399 Operating Experience Coordinator Jonathan M. Block, Esq.
Vermont Yankee Nuclear Power Station Main Street 320 Governor Hunt Road P.O. Box 566 Vernon, VT 05354 Putney, VT 05346-0566 G. Dana Bisbee, Esq. Mr. John F. McCann Deputy Attorney General Director, Licensing 33 Capitol Street Entergy Nuclear Operations, Inc.
Concord, NH 03301-6937 440 Hamilton Avenue White Plains, NY 10601 Chief, Safety Unit Office of the Attorney General Mr. Gary J. Taylor One Ashburton Place, 19th Floor Chief Executive Officer Boston, MA 02108 Entergy Operations 1340 Echelon Parkway Jackson, MS 39213
Vermont Yankee Nuclear Power Station cc:
Mr. John T. Herron Ms. Stacey M. Lousteau Sr. VP and Chief Operating Officer Treasury Department Entergy Nuclear Operations, Inc. Entergy Services, Inc.
440 Hamilton Avenue 639 Loyola Avenue White Plains, NY 10601 New Orleans, LA 70113 Mr. Oscar Limpias Mr. Norman L. Rademacher Vice President, Engineering Director, NSA Entergy Nuclear Operations, Inc. Vermont Yankee Nuclear Power Station 440 Hamilton Avenue P.O. Box 0500 White Plains, NY 10601 185 Old Ferry Road Brattleboro, VT 05302-0500 Mr. Christopher Schwarz Vice President, Operations Support Mr. Raymond Shadis Entergy Nuclear Operations, Inc. New England Coalition 440 Hamilton Avenue Post Office Box 98 White Plains, NY 10601 Edgecomb, ME 04556 Mr. Michael J. Colomb Mr. James P. Matteau Director of Oversight Executive Director Entergy Nuclear Operations, Inc. Windham Regional Commission 440 Hamilton Avenue 139 Main Street, Suite 505 White Plains, NY 10601 Brattleboro, VT 05301 Mr. William K. Sherman Assistant General Counsel Vermont Department of Public Service Entergy Nuclear Operations, Inc. 112 State Street 440 Hamilton Avenue Drawer 20 White Plains, NY 10601 Montpelier, VT 05620-2601 Mr. Theodore Sullivan Mr. Michael D. Lyster Site Vice President 5931 Barclay Lane Entergy Nuclear Operations, Inc. Naples, FL 34110-7306 Vermont Yankee Nuclear Power Station P.O. Box 0500 Ms. Charlene D. Faison 185 Old Ferry Road Manager, Licensing Brattleboro, VT 05302-0500 440 Hamilton Avenue White Plains, NY 10601 Mr. James H. Sniezek 5486 Nithsdale Drive Salisbury, MD 21801 Mr. Garrett D. Edwards 814 Waverly Road Kennett Square, PA 19348