ML100320052

American Society of Mechanical Engineers Code,Section XI, Inservice Inspection Program for Fourth Ten-Year Inservice Inspection Interval & Associated 10 CFR 50.55a Requests - Additional Supplemental Information Relating to Relief Request 1

ML100320052
Person / Time
Site:	Nine Mile Point
Issue date:	01/28/2010
From:	Joseph Pacher Constellation Energy Group, Nine Mile Point
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
IISI-003, TAC ME0993
Download: ML100320052 (5)

Text

P.O. Box 63 C EN G Lycoming, NY 13093 a joint venture of Constellation 61-:Z'D Energy, NINE MILE POINT NUCLEAR STATION January 28, 2010 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

Nine Mile Point Nuclear Station Unit No. 1; Docket No. 50-220 American Society of Mechanical Engineers (ASME) Code,Section XI, Inservice Inspection Program for the Fourth Ten-Year Inservice Inspection Interval and Associated 10 CFR 50.55a Requests - Additional Supplemental Information Relating to Relief Request IISI-003 (TAC No. ME0993)

REFERENCES:

(a) Letter from P. A. Mazzaferro (NMPNS) to Document Control Desk (NRC),

dated March 16, 2009, American Society of Mechanical Engineers (ASME)

Code,Section XI, Inservice Inspection Program for the Fourth Ten-Year Inservice Inspection Interval and Associated 10 CFR 50.55a Requests (b) Letter from R. V. Guzman (NRC) to S. L. Belcher (NMPNS), dated August 18, 2009, Request for Additional Information Regarding Nine Mile Point Nuclear Station, Unit No. 1, Relating to Relief Request, 1ISI-003, Associated with the Fourth 10-Year Inservice Inspection Interval (TAC No. ME0993)

(c) Letter from J. E Pacher (NMPNS) to Document Control Desk (NRC), dated October 2, 2009, American Society of Mechanical Engineers (ASME) Code,Section XI, Inservice Inspection Program for the Fourth Ten-Year Inservice Inspection Interval and Associated 10 CFR 50.55a Requests - Response to NRC Request for Additional Information (TAC No. ME0993)

Nine Mile Point Nuclear Station, LLC (NMPNS) hereby transmits additional supplemental information requested by the NRC in support of a previously submitted request for alternative (No. 1ISI-003) under the provision of 10 CFR 50.55a(a)(3). This 10 CFR 50.55a request was included within the Nine Mile Point Unit I Fourth Ten-Year Inservice Inspection Plan and Schedule that was submitted by letter dated

-A047

Document Control Desk January 28, 2010 Page 2 March 16, 2009 (Reference a). The NMPNS response to the request for additional information documented in the NRC's letter dated August 18, 2009 (Reference b) was provided in the NMPNS letter dated October 2, 2009 (Reference c). The additional supplemental information, provided in the Attachment to this letter, responds to a follow-up NRC request that was provided in an email from the NRC to NMPNS on December 16, 2009. This letter contains no new regulatory commitments.

Should you have any questions regarding the information in this submittal, please contact T. F. Syrell, Licensing Director, at (315) 349-5219.

Very truly yours, Pacher

/osephE. Engineering

?VManager Services JEP/DEV

Attachment:

Nine Mile Point Unit I - Additional Supplemental Information Relating to Fourth Ten-Year Inservice Inspection Interval Request No. 1ISI-003 cc: S. J. Collins, NRC R. V. Guzman, NRC Resident Inspector, NRC

ATTACHMENT NINE MILE POINT UNIT 1 ADDITIONAL SUPPLEMENTAL INFORMATION RELATING TO FOURTH TEN-YEAR INSERVICE INSPECTION INTERVAL REQUEST NO. IISI-003 Nine Mile Point Nuclear Station, LLC January 28, 2010

ATTACHMENT NINE MILE POINT UNIT 1 ADDITIONAL SUPPLEMENTAL INFORMATION RELATING TO FOURTH TEN-YEAR INSERVICE INSPECTION INTERVAL REQUEST NO. IISI-003 By letter dated March 16, 2009, Nine Mile Point Nuclear Station, LLC (NMPNS) submitted the Nine Mile Point Unit 1 (NMP1) Fourth Ten-Year Inservice Inspection (ISI) Plan and Schedule and associated 10 CFR 50.55a request no. IISI-003 pursuant to 10 CFR 50.55a(a)(3). The NMPNS response to the NRC request for additional information (RAI) relating to request no. 1ISI-003, documented in the NRC's letter dated August 18, 2009, was provided in the NMPNS letter dated October 2, 2009.

In an email from the NRC to NMPNS on December 16, 2009, the NRC provided a follow-up request relating to the NMPNS response to RAI No. 2 that was previously submitted in the NMPNS letter dated October 2, 2009. RAI No. 2 addressed certain issues relating to the internal flooding probabilistic risk assessment (PRA) analyses performed to support the risk-informed, safety-based (RISB) ISI program application described in request no. IISI-003. The follow-up request is repeated below (in italics),

followed by the NMPNS response.

NRC RAI No. 2 Follow-upRequest IF-C8 capability category III is met if no flood sources were screened out based on reliance on operator action to prevent challenges to normalplant operation. The staff interprets "screenedout" (based on the ASME standard definition of screening) to mean that the possible effects of the flood sourcefailure was eliminated from further consideration such that no internal flood scenarios are representative or boundingfor the screened source. NMPNSs 9/9/09 response thatflood sources from smaller diameter piping were screened out because generally they are lower risk than other, modeled, larger diameter piping does not directly address the screening criteriadiscussed in IF-C8.

Were any flooding sources screened out based solely on a possible operator action to isolate the flood source before normal plant operation is challenged, and for which there are no included scenarios that would bound the particularaffects of the screened source? If so, please describe the scenario including the time available before normal plant operation is challenged, the indicationsavailable to the operator, and the proceduresdirecting the operators(pre-challenge)to isolate the flood source.

Response

No flooding sources were screened out based solely on a possible operator action to isolate the flooding source before normal plant operation is challenged, and for which there are no included scenarios that would bound the effects of the screened source.

With regard to the previous NMPNS response to RAI No. 2 (October 2, 2009 NMPNS letter) that certain flooding sources from small diameter piping were "screened," NMPNS has performed additional analyses for internal flooding events initiated due to small diameter piping failures in the Reactor and Turbine buildings by considering the actual lengths of the small diameter piping present'and applying appropriate failure frequencies. Similar to the flooding analyses performed for larger diameter piping sources in these buildings, the additional analyses included accident sequences where operators successfully isolate the source as well as sequences where operators fail to isolate the source. Calculated core damage frequency (CDF) values for flooding events involving the small diameter piping sources are 1.1E-08 per year or less; therefore, the Code Case N-716 criterion of 1E-06 per year is not exceeded. The internal flooding analyses performed for the RISB ISI program application, as supplemented by the additional analyses 1 of 2

ATTACHMENT NINE MILE POINT UNIT 1 ADDITIONAL SUPPLEMENTAL INFORMATION RELATING TO FOURTH TEN-YEAR INSERVICE INSPECTION INTERVAL REQUEST NO. 11SI-003 described above, effectively meet PRA supporting requirement IF-C8 (IFSN-A16), capability Category III.

With regard to the previous NMPNS response to RAI No. 2 that certain flood locations (areas) were "screened," the areas in question are the Offgas building, the Waste Disposal building, and the Administration building. Water from a flooding source in these buildings (service water, fire water, and city water piping) can eventually propagate to and impact PRA-modeled equipment in the adjacent Turbine building. However, there are other included, modeled flooding scenarios for the Turbine Building involving these same flooding sources (service water, fire water, and city water piping) that bound the effects of flooding events in the Offgas, Waste Disposal, and Administration buildings. Thus, consistent with the staff interpretation stated in the NRC follow-up request, screening out of flooding sources in the Offgas, Waste Disposal, and Administration buildings is acceptable in the internal flooding analyses performed for the RIS B ISI application. In addition, based on the flooding scenarios already modeled for the Turbine building, including the additional analyses performed for small diameter piping failures in the Turbine building described above, the CDF for flooding events involving sources in the Offgas, Waste Disposal, and Administration buildings would be much less than the Code Case N-716 criterion of 1E-06 per year.

Based on the additional analyses performed for small diameter piping failures in the Reactor and Turbine buildings described above, NMPNS is also revising its previous response to RAI No. 2 with regard to PRA supporting requirement IF-D3a (IFEV-A3), as follows:

SR IF-D3a There was no grouping of internal flooding initiating events with other internal initiating events.

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