ML073130022

Electronic Transmission, Draft Request for Additional Information Regarding One Time Integrated Leak Rate Interval Extension from 10 to 15 Years

ML073130022
Person / Time
Site:	Limerick
Issue date:	11/09/2007
From:	Peter Bamford NRC/NRR/ADRO/DORL/LPLI-2
To:	Chernoff H NRC/NRR/ADRO/DORL/LPLI-2
Bamford, Peter J., NRR/DORL 415-2833
References
TAC MD5198, TAC MD5199
Download: ML073130022 (4)

Text

November 9, 2007 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager /ra/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

LIMERICK GENERATING STATION, UNIT NOS 1 AND 2 -

ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING ONE TIME INTEGRATED LEAK RATE INTERVAL EXTENSION FROM 10 TO 15 YEARS (TAC NOS. MD5198 AND MD5199)

The attached draft request for additional information (RAI) was sent by electronic transmission on November 8, 2007, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call with Exelon in order to clarify certain items in the licensee=s submittal. The draft RAI is related to Exelon=s submittal dated February 20, 2007, regarding a request to extend the Containment type A Integrated Leak Rate Test interval for Limerick Generating Station, Units 1 and 2 from 10 to 15 years. The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to determine and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.

Docket Nos. 50-352 and 50-353

Enclosure:

As stated

November 9, 2007 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

LIMERICK GENERATING STATION, UNIT NOS 1 AND 2 -

ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING ONE TIME INTEGRATED LEAK RATE INTERVAL EXTENSION FROM 10 TO 15 YEARS (TAC NOS. MD5198 AND MD5199)

The attached draft request for additional information (RAI) was sent by electronic transmission on November 8, 2007, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call with Exelon in order to clarify certain items in the licensee=s submittal. The draft RAI is related to Exelon=s submittal dated February 20, 2007, regarding a request to extend the Containment type A Integrated Leak Rate Test interval for Limerick Generating Station, Units 1 and 2 from 10 to 15 years. The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to determine and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.

Docket Nos. 50-352 and 50-353

Enclosure:

As stated DISTRIBUTION:

Public RidsNrrPMPBamford LPL1-2 R/F GThomas, NRR Accession No.: ML073130022 *via email OFFICE LPL1-2/PM EGCB/BC NAME PBamford KManoly*

DATE 11/9/2007 11/07/2007 OFFICIAL RECORD COPY

DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGES FOR TYPE A INTEGRATED LEAK RATE TEST INTERVAL EXTENSION LIMERICK GENERATING STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-352 AND 50-353 By letter dated February 20, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML070530296), Exelon Generation Company, LLC, submitted a license amendment request (LAR) for Limerick Generating Station (LGS), Unit Nos. 1 and 2. The proposed amendment would provide a one-time extension of the containment Type A Integrated Leak Rate Test interval from 10 years to 15 years for each unit.

The Nuclear Regulatory Commission (NRC) Staff has been reviewing the submittal and has determined that additional information is needed to complete its review.

In Section 4.4 titled Containment Inspections in Attachment 1 of the LAR, it is stated that during the most recent Unit 1 IWE examinations, One (1) recordable indication of a pit in the suppression pool steel liner was isolated from further corrosion by performing a qualified coating repair. The remaining wall thickness under this pit was greater than the required design minimum wall thickness. Previously, one other less severe pit was similarly isolated. In order to help the NRC staff understand the nature of the pitting degradation and its management, please provide the following information.

1. The extent, depth, location/environment and root cause of these pits in the suppression pool liner of Unit 1, the corrective actions taken and evaluations performed that deemed them to be acceptable. Explain how the required design minimum wall thickness was determined.

What actions are being taken to monitor these indications to ensure that there is no further deterioration of degradation and explain why IWE augmented examinations are not required?

2 Provide information of the nature, extent, depth, locations/environment and cause of other pitting degradation indications that have been previously found, if any, on the suppression pool liners of both Units 1 and 2 and how they are being managed.