ML102571447
| ML102571447 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 09/07/2010 |
| From: | Price J A Dominion, Dominion Energy Kewaunee |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-04-002 | |
| Download: ML102571447 (4) | |
Text
Dominion Energy Kewaunee, Inc. V 1 D mnin 5060 Dominion Boulevard, Glen Allen, VA 23060 Dominion September 7, 2010 U. S. Nuclear Regulatory Commission Serial No.10-025 Attention:
Document Control Desk LIC/JG RO Washington, DC 20555-0001 Docket No. 50-305 License No. DPR-43 DOMINION ENERGY KEWAUNEE, INC.KEWAUNEE POWER STATION RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING NRC GENERIC LETTER 2004-02 The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors, on September 13, 2004. This GL was issued to resolve NRC Generic Safety Issue (GSI) 191, Assessment of Debris Accumulation on PWR Sump Performance.
GL 2004-02 requested that addressees perform an evaluation of the Emergency Core Cooling System (ECCS) and Containment Spray System (CSS) recirculation functions in light of the information provided in the letter and, if appropriate, take additional actions to ensure system functionality.
Dominion Energy Kewaunee (DEK) responded to GL 2004-02 for Kewaunee Power Station (KPS) by letters dated March 7, 2005, July 6, 2005, September 1, 2005, February 29, 2008, and May 21, 2008. By letter dated December 18, 2008, additional updates were provided following resolution of the topics of downstream effects and chemical effects.On August 14, 2009, the NRC staff transmitted a request for additional information (RAI)(reference
- 1) regarding the response to GL 2004-02 for KPS. Following a telephone conference between DEK and NRC staff members on September 15, 2009, revised RAI Questions 5, 6, 7, and 12 (reference
- 2) were received from NRC on October 14, 2009.Several teleconferences were held between DEK and NRC staff members between September 2009 and July 2010 to discuss DEK's proposed responses to the RAI questions.
On May 20, 2010, DEK verbally informed NRC staff of our intent to remove certain fibrous materials from the containment building in order to limit the quantity of fiber generated by a loss of coolant accident and prevent a filtering bed of fiber from forming on the containment recirculation strainer.
Serial No.10-025 Docket No. 50-305 GL 2004-02 RAI Response Page 2 of 4 In response to a NRC staff request, a holistic overview of the resolution to GSI-191 at KPS is provided in Attachment 1 to this letter. A summary of the planned changes and an implementation schedule are provided in Attachment
- 3. Attachment 4 provides a list of enclosures that are included with this response.If you have any questions regarding this response, please contact Mr. Jack Gadzala at (920) 388-8604.Sincerely, J. Al n rice Vic P esident -Nuclear Engineering COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. J. Alan Price, who is Vice President
-Nuclear Engineering of Dominion Energy Kewaunee, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.Acknowledged before me this '1-41_day of ,,- }2MX ,2010.My Commission Expires: ___________-N'ota JA Notary PubPbi Xf w.aC "COMYI'ý iCAIck Ou GINGER LYNN MELTON I Notary Public Commonwealth of Virginia 310847 My Commission Expires Apr 30, 2013 Serial No.10-025 Docket No. 50-305 GL 2004-02 RAI Response Page 3 of 4 Attachments:
- 1. Holistic Overview of GSI-1 91 Resolution for Kewaunee Power Station 2. Summary of Planned Changes and Implementation Schedule 3. Response to Request for Additional Information:
Generic Letter 2004-02 4. List of Enclosures
References:
- 1. Letter from Peter S. Tam (NRC) to David A. Heacock (DEK), "Kewaunee Power Station -Request for Additional Information Regarding Response.to Generic Letter 2004-02 (TAC No. MC4691)," dated August 14, 2009.2. Email from Peter S. Tam (NRC) to Jack Gadzala, Thomas Breene and Craig Sly (DEK), "Kewaunee
-Revised Questions 5, 6, 7, and 12 of the 8/14/09 RAI (TAC MC4691)," dated October 14, 2009.Commitments made in this letter: 1. The following fibrous insulation on equipment/piping in the RCS Loop Vaults will be removed and replaced: a. Fibrous insulation (TempMat) on the pressurizer surge line pipe whip restraints will be removed and replaced with a non-fibrous material.b. Fibrous insulation on the Service Water piping that passes through the top of the "B" reactor coolant pump vault will be removed.2. The JM Thermobestos insulation (calcium silicate insulation with asbestos fibers)in the "A" steam generator vault will be secured with stainless steel banding, similar to that performed in the "B" steam generator vault (opposite train) to enable use of a Zone of Influence (ZOI) size equal to 5.45D.3. The remaining fibrous material in containment will be assumed to be Fines and subject to transport to the recirculation strainer.4. The containment refueling cavity drain standpipe will be modified to remove the 1 inch x 1 inch grid/grating recessed into the top of the standpipe to eliminate the potential for debris to be captured on the drain opening.5. The calculation of the minimum containment sump level at the start of recirculation will be revised to identify a postulated break at the top of the Pressurizer as a non-limiting case for evaluating the recirculation system performance, or that scenario will be removed from the calculation.
Serial No.10-025 Docket No. 50-305 GL 2004-02 RAI Response Page 4 of 4 6. The allowable quantity of latent debris (dirt, dust) in containment will be limited to 51 Ibm to prevent formation of a filtering bed of fiber on the recirculation strainer when combined with the remaining fiber in containment.
- 7. A thin bed of fiber on the recirculation strainer will be defined as greater than or equal to 1/16 inch thickness.
- 8. The Dominion fleet latent debris sampling and evaluation procedure will be revised prior to the next refueling outage to require a sampling frequency of every other refueling outage for low-fiber plants that are dependent upon plant cleanliness to prevent formation of a filtering bed of fiber on the recirculation strainer.
The procedure will specify the sampling frequency may be relaxed after several consecutive sample results (outages) that identify minimal or no increasing volume of measured latent debris and ample latent debris inventory margin.9. An updated response will be submitted within 90 days of issuance of the final SE on WCAP-16793-NP regarding in-vessel downstream effects.10. Following implementation of these changes, the Kewaunee Updated Safety Analysis Report will be updated to reflect the revised recirculation system design basis, including the maximum allowable fibrous debris in containment.
- 11. Unless specified otherwise, all changes discussed above will be completed no later than two refueling outages following the current operating cycle's refueling outage.cc: Regional Administrator, Region III U. S. Nuclear Regulatory Commission 2443 Warrenville Road Suite 210 Lisle, IL 60532-4352 Mr. K. D..Feintuch Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-H4A.11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Kewaunee Power Station