ML081080077

Request for Additional Information for the Review of the Oyster Creek Nuclear Generating Station, License Renewal Application

ML081080077
Person / Time
Site:	Oyster Creek
Issue date:	04/29/2008
From:	Ashley D NRC/NRR/ADRO/DLR/RLRA
To:	Rausch T AmerGen Energy Co
Ashley D, NRR/ADRO/DLR, 415-3191
References
FOIA/PA-2008-0306, TAC MD7624
Download: ML081080077 (7)

Text

April 29, 2008 Mr. Timothy Rausch Site Vice President Oyster Creek Nuclear Generating Station AmerGen Energy Company, LLC P.O. Box 388 Forked River, NJ 08731

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION CONCERNING METAL FATIGUE AND ITS IMPACT ON THE REVIEW OF THE OYSTER CREEK NUCLEAR GENERATING STATION, LICENSE RENEWAL APPLICATION (TAC NO. MD7624)

Dear Mr. Rausch:

By letter dated July 22, 2005, AmerGen Energy Company, LLC (AmerGen) submitted to the U.S.Nuclear Regulatory Commission (NRC or the staff) an application pursuant to Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54), to renew the operating license for Oyster Creek Nuclear Generating Station. As indicated by the Staff in the Commission Notice dated April 3, 2008, the NRC staff has become aware of issues concerning metal fatigue calculations that may have an impact on the review of AmerGens application for license renewal. The staff has identified, in the enclosure, areas where additional information is needed.

These questions were discussed with members of your staff during two conference calls on April 7, 2008, and April 15, 2008. A mutually agreeable date for a response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-3191 or via e-mail at Donnie.Ashley@nrc.gov.

Sincerely,

/RA/

Donnie J. Ashley, Senior Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-219

Enclosure:

As stated cc w/encl: See next page

ML081080077 OFFICE PM:RPB1:DLR LA:DLR OGC/NLO BC:RPB1:DLR NAME DAshley SFigueroa EWilliamson LLund DATE 4/23/08 4/22/08 4/25/08 4/29/08

Oyster Creek Nuclear Generating Station cc:

Site Vice President - Oyster Creek Senior Resident Inspector Nuclear Generating Station U.S. Nuclear Regulatory Commission AmerGen Energy Company, LLC P.O. Box 445 P.O. Box 388 Forked River, NJ 08731 Forked River, NJ 08731 Director - Licensing and Regulatory Affairs Senior Vice President- Operations AmerGen Energy Company, LLC Support Correspondence Control AmerGen Energy Company, LLC P.O. Box 160 4300 Winfield Road Kennett Square, PA 19348 Warrenville, IL 60555 Manager Licensing - Oyster Creek Kathryn M. Sutton, Esquire Exelon Generation Company, LLC Morgan, Lewis, & Bockius LLP Correspondence Control 1111 Pennsylvania Avenue, NW P.O. Box 160 Washington, DC 20004 Kennett Square, PA 19348 Patrick Mulligan, Chief Ron Bellamy, Region I Bureau of Nuclear Engineering U.S. Nuclear Regulatory Commission New Jersey Department of 475 Allendale Road Environmental Protection King of Prussia, PA 19406-1415 25 Arctic Parkway Ewing, NJ 08638 Correspondence Control Desk AmerGen Energy Company, LLC Vice President - Licensing and 200 Exelon Way, KSA 1-N-1 Regulatory Affairs Kennett Square, PA 19348 AmerGen Energy Company, LLC 4300 Winfield Road Plant Manager Warrenville, IL 60555 Oyster Creek Nuclear Generating Station AmerGen Energy Company, LLC Regional Administrator, Region I P.O. Box 388 U.S. Nuclear Regulatory Commission Forked River, NJ 08731 475 Allendale Road King of Prussia, PA 19406-1415 Associate General Counsel Exelon Generation Company, LLC Mayor of Lacey Township 4300 Winfield Road 818 West Lacey Road Warrenville, IL 60555 Forked River, NJ 08731 Chief Operating Officer (COO)

Manager Regulatory Assurance AmerGen Energy Company, LLC Oyster Creek Generating Station 4300 Winfield Road AmerGen Energy Company, LLC Warrenville, IL 60555 P.O. Box 388 Forked River, NJ 08731

Oyster Creek Nuclear Generating Station cc:

Senior Vice President - Mid-Atlantic Operations AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348

Lettter to T. Rausch from D. Ashley, dated April 29, 2008 DISTRIBUTION:

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION CONCERNING METAL FATIGUE AND ITS IMPACT ON THE REVIEW OF THE OYSTER CREEK NUCLEAR GENERATING STATION, LICENSE RENEWAL APPLICATION (TAC NO. MD7624)

HARD COPY:

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DAshley GMiller JLilliendahl, RI MModes, RI MBaty RidsOpaMail

OYSTER CREEK NUCLEAR GENERATING STATION LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION RAI 4.3.4-1 The staff identified a concern regarding the methodology used by license renewal applicants to demonstrate the ability of nuclear power plant components to withstand the cyclic loads associated with plant transient operations for the period of extended operation. The analysis methodology of concern focused on the use of a Greens function to calculate stresses used in calculating the fatigue cumulative usage factor (CUF). It involves a simplified input for applying the Greens function in which only one value of stress is used to represent the stress field of actual plant transients. The use of this methodology requires a great deal of engineering judgment by the analyst to assure the simplification still provides conservative results. The staff understands that this methodology was used to calculate the environmentally impacted CUF for the Oyster Creek reactor recirculation outlet nozzle. The staff requests that OGCS perform an additional stress analysis of the recirculation outlet nozzle in accordance with the ASME Code,Section III, Subsection NB-3200 methodology (all six stress components are retained in the analysis) to confirm that the results of the previous Greens function evaluation is acceptable.

Provide a summary of the results which includes the following information:

• A comparison of the calculated stresses and fatigue usage factors using the Greens function evaluation and the additional confirmatory analysis for each plant transient and transient pairs that contributed to the CUF.

• The environmental factor, Fen, used to evaluate each transient pair.

• A discussion of any differences in the analysis input parameters and analysis assumptions between the Greens function evaluation and the confirmatory analysis.

RAI 4.3.4-2 Confirm the reactor recirculation outlet nozzle was the only location where the Greens function (simplified calculation methodology) methodology was used to evaluate the fatigue CUF for license renewal.