ML13134A264
| ML13134A264 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 05/13/2013 |
| From: | Henderson K Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-04-002 | |
| Download: ML13134A264 (5) | |
Text
Kelvin Henderson DUKE Vice President ENERGY.
Catawba Nuclear Station 803-701-4251 Duke Energy CNO1VP 1 4800 Concord Rd.
York, SC 29745 May 13, 2013 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001
Subject:
Duke Energy Carolinas, LLC (Duke Energy)
Catawba Nuclear Station (Catawba), Units 1 and 2 Docket Nos. 50-413 and 50-414 Closure Options for Generic Safety Issue (GSI)-191, "Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance" in Resolution of Final Issues Related to Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors" On November 21, 2008, the Nuclear Regulatory Commission (NRC) issued a Request for Additional Information (RAI) regarding supplemental responses to GL 2004-02.
On August 13, 2012, Catawba submitted final responses to all but one NRC question in the November 21, 2008 RAI. For the one remaining RAI question related to in-vessel downstream effects, Catawba committed to resolving the issue pending completion of NRC review and approval of the methodology described in WCAP-16793-NP, Revision 2.
As described in detail in the August 13, 2012 submittal, Catawba has designed and implemented modifications to the plant configuration in both Units 1 and 2 to enhance post-accident performance related to GSI-191, including:
Removal of a large quantity of fibrous insulation from the Unit 1 containment (complete)
Design and implementation of a wholly modified, larger and more efficient strainer that incorporates bypass eliminators, resulting in a low downstream "pass-through" fibrous debris quantity in the reactor core of less than 15 grams/fuel assembly (complete in both units)
Implementation of Emergency Core Cooling System (ECCS) Water Management Initiative modifications (complete in both units)
The August 13, 2012 submittal also outlined the remaining commitment related to closure of GSI-191 for Catawba. The commitment in that letter was associated with the Catawba response to in-vessel downstream effects. The status of this commitment is updated in the attachment to this letter.
www.duke-energy.corn
U.S. Nuclear Regulatory Commission May 13, 2013 Page 2 On July 9, 2012, the NRC technical staff issued Commission Paper SECY-12-0093, "Closure Options for Generic Safety Issue - 191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance". In this letter, the staff recommended that licensees be allowed the flexibility to choose any of three options to resolve remaining issues on GSI-1 91:
Option 1 - Compliance with 10 CFR 50.46 Based on Approved Models; Option 2 - Mitigative Measures and Alternative Methods Approach; and Option 3 - Different Regulatory Treatment for Suction Strainer and In-Vessel Effects. The associated Staff Requirements Memorandum (SRM) approving the SECY-12-0093 recommendation was subsequently issued on December 14, 2012.
In accordance with the SECY letter recommendation, Catawba will pursue GSI-191 Closure Option 1 since both Units 1 and 2 meet the requirements of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors", based on approved models for analyses, strainer head loss testing, and in-vessel downstream effects. WCAP-16793-NP, Revision 2 was approved by the NRC Safety Evaluation (SE) dated April 8, 2013; therefore, successful completion of the analysis in accordance with this SE will show compliance with 10 CFR 50.46 as it relates to in-vessel downstream effects, and will resolve the final outstanding RAI question for Catawba.
There are no new commitments made herein; however, per NRC guidance, the completion date for the commitment in the attachment to this letter is revised to July 31, 2013 to allow time for the appropriate documentation of the in-vessel downstream effects analysis in accordance with the April 8, 2013 NRC SE.
If any questions arise or if additional information is needed, please contact L.J. Rudy at (803) 701-3084.
Very truly yours, Kelvin Henderson LJR/s Attachment
U.S. Nuclear Regulatory Commission May 13, 2013 Page 3 xc (with attachment):
V.M. McCree, NRC Region II Administrator Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 J.S. Kim, NRC Project Manager 11555 Rockville Pike Mail Stop 8 C2 Rockville, MD 20852-2738 G.A. Hutto, III, NRC Senior Resident Inspector Catawba Nuclear Station S.E. Jenkins, Manager Radioactive and Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 2600 Bull St.
Columbia, SC 29201
U.S. Nuclear Regulatory Commission May 13, 2013 Page 4 Kelvin Henderson affirms that he is the person who subscribed his name to the foregoing statement, and that all the matters and facts set forth herein are true and correct to the best of his knowledge.
Kelvin Henderson, Vice President, Catawba Nuclear Station Subscribed and sworn to me:
S-/3-2~'O, 3 ir4 Date
, Notary Public My commission expires:
Date SEAL.
Attachment Catawba Nuclear Station Generic Letter 2004-02 Supplemental Response Commitment RAI Commitment Due Date
Response
29 Catawba will address the in-vessel July 31, 2013 downstream effects issue.