BVY 09-067, Response to Request for Additional Information Related to Technical Specifications Proposed Change No. 284 Change to Requirements for Inoperable Containment Isolation Valves
| ML093240081 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 11/16/2009 |
| From: | Michael Colomb Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BVY 09-067 | |
| Download: ML093240081 (4) | |
Text
4.,
- ý Entergy Entergy Nuclear Operations, Inc.
Vermont Yankee P.O. Box 0250 Vernon, VT 05354 Tel 802 257 7711 Michael J Colomb Site Vice President November 16, 2009 BVY 09-067 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
REFERENCE:
Response to Request for Additional Information related to Technical Specifications Proposed Change No. 284 Change to Requirements for Inoperable Containment Isolation Valves Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28
- 1. Letter, Entergy to USNRC, 'Technical Specifications Proposed Change No. 284 Change to Requirements for Inoperable Containment Isolation Valves," BVY 09-052, dated September 16, 2009
Dear Sir or Madam:
In Reference (1), Entergy Nuclear Operations, Inc. (ENO) submitted a proposed change to amend Operating License DPR-28 for the Vermont Yankee Nuclear Power Station (VY). This letter is in response to your staff's request for additional information (RAI) related to this proposed amendment. Attachment 1 to this submittal provides ENO's response to each of the RAI questions.
These responses were discussed with your staff via telecom on November 9, 2009.
This supplement to the original license amendment request does not change the scope or conclusions in the original application, nor does it change ENO's determination of no significant hazards consideration.
There are no new regulatory commitments made in this letter.
Should you have any questions or require additional information concerning this transmittal, please contact Mr. David Mannai at (802) 451-3304.
I declare under penalty of perjury that the foregoing is true and correct. Executed on November 16, 2009.
Sincerely, MJC/JMD A6c1
BVY 09-67 / Page 2 of 2 : Response to Request for Additional Information cc:
Mr. Samuel J. Collins Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. James S. Kim, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 08C2A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601
BVY 09-067 Docket No. 50-271 Vermont Yankee Nuclear Power Station Proposed Change 284 Response to Request for Additional Information
BVY 09-067 / Attachment 1 / Page 1 of 1 Response to Request for Additional Information RAI No. 1 Provide a safety basis that explains why it is acceptable to isolate the affected containment penetration upon an inoperable containment isolation valve instead of conducting an orderly shutdown.
Response to RAI No.1 The function of Primary Containment Isolation Valves (PCIVs), in combination with other accident mitigation systems, is to limit fission product release during and following postulated Design Basis Accidents (DBA) to within the limits of 10CFR50.67. Systems relied upon to mitigate DBAs are designed to accommodate a single active failure. When a PCIV is made or found to be inoperable for the containment function, Technical Specifications (TS) 3.7.D.2 provides action to be taken that compensate for the inoperable PCIV. These actions allow continued operation and allow time to diagnose and repair the cause of the inoperability and to return the PCIV to operation without the need for a plant shutdown. If the TS requirements can not be met then TS 3.7.D.3 is entered and the plant needs to be in the cold shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The establishment of Limiting Conditions for Operations (LCOs) provides reasonable time frames and actions to compensate for the inoperable PCIV. In this case, the proposed change would allow the condition to exist for an indefinite timeframe, subject to other system level LCO limitations, provided the affected penetration flow path is isolated by the use of at least one closed and deactivated automatic valve, closed manual valve, or blind flange.
These compensatory measures are considered passive means of isolating the penetration and preserve the single active failure assumption that forms the Vermont Yankee licensing basis relative to DBA Mitigation. This change is consistent with the intent of provisions contained in NUREG 1433 "Standard Technical Specifications General Electric Plant, BWR/4," Revision 3 and are considered to provide an acceptable level of safety.
RAI No. 2 Provide a safety basis that explains why it is acceptable to verify the penetration flow path is isolated every 31 days instead of daily.
Response to RAI No.2 For affected penetrations that have been isolated in accordance with TS 3.7.D.2, the penetration flow path must be verified to be isolated on a periodic basis. The current TS require verification daily and the proposed TS would require verification once per 31 days. This once per 31 days is consistent with the timeframe contained in NUREG 1433. The required verification does not require any testing or device manipulation. Rather, it requires verification that those devices used to isolate the penetration and capable of being mispositioned are in the correct position. The once per 31 days is considered adequate because the devices are operated under administrative controls and the probability of misalignment is low. Entergy considers the once per 31 days as a confirmatory verification that is adequate based on the other administrative controls that are in place to maintain operators awareness of the inoperable PCIV. These include, but are not limited to, logging the LCO entry in the control room log and discussing the outstanding LCOs at shift briefs. These actions ensure that the control room staff is continuously aware of the status of LCOs and their impact on plant operation. The need to do a daily check is not considered necessary and a one per 31 day verification is considered to provide an adequate level of safety.