ML101320059
| ML101320059 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 05/19/2010 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Pardee C Exelon Generation Co |
| Hughey J, NRR/DORL, 301-415-3204 | |
| References | |
| TAC ME2159 | |
| Download: ML101320059 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 19,2010 Mr. Charles G. Pardee President and Chief Nuclear Officer Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNIT 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR ONE-TIME FIVE-YEAR CONTAINMENT TYPE A INTEGRATED LEAK RATE TEST INTERVAL EXTENSION (TAC NO. ME2159)
Dear Mr. Pardee:
By letter to the Nuclear Regulatory Commission (NRC) dated August 28, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092440053), as supplemented by letter dated February 25,2010 (ADAMS Accession No. ML100560433),
Exelon Generation Company, LLC, (Exelon) submitted a License Amendment Request (LAR) for Peach Bottom Atomic Power Station (PBAPS), Unit 2. The submittal seeks to revise Technical Specification 5.5.12 to reflect a one-time extension of the containment Type A Integrated Leak Rate Test (ILRT) from 10 to 15 years. The one-time extension would require a Type A ILRT to be performed no later than October of 2015. The NRC staff has reviewed the request submitted by the licensee, and the associated supplement, and determined that additional information is needed as set forth in the Enclosure.
The draft questions were sent to Thomas Loomis, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On May 12, 2010, Mr. Loomis indicated that the licensee will submit a response by June 12, 2010. Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108.
C. Pardee
- 2 If you have any questions, please contact John Hughey at (301) 415-3204.
Sincerely, fi1!D~~
John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277
Enclosure:
Request for Additional Information cc: Distribution via ListServ
REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST FOR ONE-TIME FIVE-YEAR CONTAINMENT TYPE A INTEGRATED LEAK RATE TEST (ILRT) INTERVAL EXTENSION PEACH BOTTOM ATOMIC POWER STATION - UNIT 2 DOCKET NO. 50-277 By letter to the Nuclear Regulatory Commission (NRC) dated August 28, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092440053), as supplemented by letter dated February 25,2010 (ADAMS Accession No. ML100560433),
Exelon Generation Company, LLC, (Exelon) submitted a License Amendment Request (LAR) for Peach Bottom Atomic Power Station (PBAPS), Unit 2. The submittal seeks to revise Technical Specification 5.5.12 to reflect a one-time extension of the containment Type A Integrated Leak Rate Test (ILRT) from 10 to 15 years. The one-time extension would require a Type A ILRT to be performed no later than October of 2015. The NRC staff has reviewed Exelon's submittal and supplement and determined that additional information, as described below, is needed to complete the review.
RAI-06
The response to RAI-02 in letter dated February 25, 2010, states that explicit consideration of external events is not warranted. The NRC staff notes that explicit consideration of external events, as described in Section 5.7 of the risk assessment (Attachment 4) in the LAR dated August 28, 2009, would require multiplying the change in core damage frequency (L~CDF) and the change in large early release frequency (~LERF) by a factor of 12.2. Multiplying the ~LERF by a factor of 12.2 would put the total ~LERF in "Region I" of the Regulatory Guide (RG) 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant Specific Changes to the Licensing Basis," acceptance guidelines (i.e. -5.5E-7 in the LAR +
-3.2E-6 in RAI response = -3.7E-6).
Please provide additional justification with regard to the February 25, 2010, response to RAI-02 that supports the conclusion that the total ~LERF would be in "Region II" of RG 1.174. NRC draft guidance on containment accident pressure credit is provided in Section 2.7 of "NRC Draft Guidance for the Use of Containment Accident Pressure in Determining the NPSH [net positive suction head] Margin of ECCS [emergency core cooling system] and Containment Heat Removal Pumps," (ADAMS Accession No. ML100550869) transmitted by letter to the Boiling Water Reactor Owners Group on March 1, 2010 (ADAMS Accession No. ML100550903).
Enclosure
C. Pardee
- 2 If you have any questions, please contact John Hughey at (301) 415-3204.
Sincerely, Ira/
John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277
Enclosure:
Request for Additional Information cc: Distribution via ListServ DISTRIBUTION:
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HChernoff DATE 5/19/2010 5/18/2010 5/19/2010 5/19/2010 OFFICIAL RECORD COpy