ML073390065
| ML073390065 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 12/10/2007 |
| From: | Kalyanam N NRC/NRR/ADRO/DORL/LPLIV |
| To: | Walsh K Entergy Operations |
| Kalyanam N, NRR/DORL/LPL4, 415-1480 | |
| References | |
| TAC MC4729 | |
| Download: ML073390065 (6) | |
Text
December 10, 2007 Mr. Kevin T. Walsh Vice President of Operations Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093
SUBJECT:
WATERFORD STEAM ELECTRIC STATION, UNIT 3 - APPROVAL OF EXTENSION REQUEST FOR CORRECTIVE ACTIONS RE GENERIC LETTER 2004-02, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN BASIS ACCIDENTS AT PRESSURIZED WATER REACTORS" (TAC NO. MC4729)
Dear Mr. Walsh:
By letter dated November 14, 2007, Entergy Operations Inc. (Entergy, the licensee), requested an extension of the December 31, 2007, due date for sump clogging corrective actions for Waterford Steam Electric Station, Unit 3 (Waterford 3), as required by Generic Letter 2004-02 "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors."
The U.S. Nuclear Regulatory Commission (NRC) has determined that for Waterford 3 it is acceptable to extend the due date for completion of strainer head-loss testing and analyses, as described in the enclosed staff evaluation of the extension request, until the completion of the Waterford 3 spring 2008 refueling outage, scheduled to end May 24, 2008.
Sincerely,
/RA/
N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-382
Enclosure:
As stated cc w/encl: See next page
- Editorial changes from staff provided evaluation OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/DSS/SSIB NRR/LPL4/BC NAME NKalyanam JBurkhardt MScott*
THiltz DATE 12/10/07 12/6/07 11/30/07 12/10/07
EVALUATION OF EXTENSION REQUEST TO COMPLETE CORRECTIVE ACTIONS GENERIC SAFETY ISSUE-191, "ASSESSMENT OF DEBRIS ACCUMULATION ON PWR SUMP PUMP PERFORMANCE" (GSI-191)/
GENERIC LETTER 2004-02, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN BASIS ACCIDENTS AT PRESSURIZED WATER REACTORS" (GL 2004-02)
WATERFORD STEAM ELECTRIC STATION, UNIT 3 DOCKET NO. 50-382 By letter dated November 14, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML073200095), Entergy Operations Inc. (Entergy, the licensee),
requested an extension of the December 31, 2007, due date for sump clogging corrective actions for Waterford Steam Electric Station, Unit 3 (Waterford 3), as required by Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors" (GL 2004-02). In its letter, Entergy stated that Waterford 3 has taken actions toward bringing Waterford 3 into compliance with GL 2004-02, including replacing the sump screens with substantially larger sump strainers during the fall 2006 refueling outage (RFO). However, re-evaluation of debris generation and debris transport analyses, re-evaluation of downstream effects (to address revised WCAP-16406-P), strainer debris head-loss testing, and chemical effects testing have not been completed. Therefore, an extension to the compliance due date of December 31, 2007, was requested to allow time for completion of these activities.
As stated in SECY-06-0078, proposed extensions to permit changes at the next outage of opportunity after December 2007 may be granted, based on the licensees request, if the NRC staff determines that:
1.
the licensee has a plant-specific technical/experimental plan with milestones and schedules to address outstanding technical issues with enough margin to account for uncertainties, and
- 2.
the licensee identifies mitigative measures to be put in place prior to December 31, 2007, and adequately describes how these mitigative measures will minimize the risk of degraded emergency core cooling system (ECCS) and containment spray system (CSS) functions during the extension period.
The SECY also states that for proposed extensions beyond several months, a licensees request will more likely be accepted if the proposed mitigative measures include temporary physical improvements to the ECCS sump or materials inside containment to better ensure a high level of ECCS sump performance.
In regard to the first criterion for approving an extension, Entergy has a plant-specific plan, with milestones and schedules, to complete the Waterford 3 GL 2004-02 required corrective actions and modifications by May 24, 2008. Specifically, Entergy plans to complete its fuel and vessel downstream effects analyses and its strainer certification/qualification report by the expected May 24, 2008, restart from its spring 2006 RFO (RFO15). Also, Entergy will subsequently update its licensing basis to reflect resolution of Waterford GSI-191 issues (completion of all GL 2004-02 corrective actions) within 60 days of completion of the Waterford 3 RFO15.
In regard to the second criterion for approving an extension, Entergy has stated that the following modifications, mitigating measures, compensatory measures, and/or favorable conditions are in effect at Waterford 3, minimizing the risk of degraded ECCS and CSS functions during the extension period:
- 1.
Entergy stated that Waterford 3 has in place a new strainer with a smaller opening size and larger flow area to accommodate the loss-of-coolant accident (LOCA)-generated debris load. The new strainer has 3/32-inch diameter perforations and a flow area of approximately 3699 square feet. The replaced screen had an area of 200 square feet. Entergy stated that the new strainer provides increased margin against blockage and excessive wear on downstream components caused by debris in the water. The small size selected for the perforations minimizes fiber-debris bypass and reduces downstream effects.
- 2.
Entergy stated that Waterford 3 has implemented the following compensatory measures to reduce the risk which may be associated with potentially degraded or nonconforming ECCS and CSS recirculation functions:
Training conducted for the licensed operators presenting the mechanisms and potential consequences of sump clogging.
Procedural guidance within the emergency operating procedures on symptoms and identification of sump blockage.
Severe accident management guidance directing consideration of refilling the refueling water tank should sump blockage become a concern.
Containment cleanliness assured by procedural controls that apply after each containment entry and prior to plant startup from an outage.
Containment foreign material exclusion procedural controls that apply to inspection, operation, maintenance, and outage activities.
Procedural guidance that ensures that containment drainage paths are unblocked.
Procedural guidance that ensures sump cleanliness and integrity The NRC believes that Entergys plan, as described herein, will result in the installation of final GSI-191 modifications that provide acceptable strainer function with adequate margin for uncertainties. Further, the NRC has concluded that Entergy has put mitigation measures in place to adequately reduce risk for the approximate 5-month extension period. Therefore, it is acceptable for Entergy to complete its Waterford 3 fuel and vessel downstream effects analyses and its strainer certification/qualification report by May 24, 2008, the expected restart date from its RFO15. Also, it is acceptable for Entergy to subsequently update the Waterford 3 licensing basis to reflect resolution of GSI-191 issues (completion of all GL 2004- 02 corrective actions) within 60 days of completion of the Waterford 3 RFO15.
Should Entergy not complete the corrective actions for GL 2004-02 more than 30 days after May 24, 2008, Entergy will need to provide the NRC staff additional justification for the delay.
November 2007 Waterford Steam Electric Station, Unit 3 cc:
Senior Vice President Entergy Nuclear Operations P.O. Box 31995 Jackson, MS 39286-1995 Senior Vice President and COO Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Vice President, Operations Support Entergy Services, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Site Vice President Waterford Steam Electric Station, Unit 3 Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 General Manager, Plant Operations Waterford Steam Electric Station, Unit 3 Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Director, Nuclear Safety & Licensing Entergy Services, Inc.
440 Hamilton Avenue White Plains, NY 10601 Director, Nuclear Safety Assurance Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Senior Manager, Nuclear Safety
& Licensing Entergy Services, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Manager, Licensing Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Mr. Timothy Pflieger Environmental Scientist - Supervisor REP&R-CAP-SPOC Louisiana Department of Environmental Quality P.O. Box 4312 Baton Rouge, LA 70821-4312 Parish President Council St. Charles Parish P.O. Box 302 Hahnville, LA 70057 Chairman Louisiana Public Services Commission P.O. Box 91154 Baton Rouge, LA 70825-1697 Mr. Richard Penrod, Senior Environmental Scientist/State Liaison Officer Office of Environmental Services Northwestern State University Russell Hall, Room 201 Natchitoches, LA 71497 Resident Inspector Waterford NPS P.O. Box 822 Killona, LA 70057-0751 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011