ML090300488

Request for Additional Information Regarding Replacement Steam Generator License Amendment

ML090300488
Person / Time
Site:	Three Mile Island
Issue date:	03/06/2009
From:	Bamford P J Plant Licensing Branch 1
To:	Pardee C G Exelon Nuclear
Bamford, Peter J., NRR/DORL 415-2833
References
TAC MD9923
Download: ML090300488 (3)

Text

UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 March 6, 2009 Mr. Charles Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 THREE MILE ISLAND NUCLEAR STATION, UNIT 1 -REQUEST FOR ADDITIONAL INFORMATION REGARDING REPLACEMENT STEAM GENERATOR LICENSE AMENDMENT (TAC NO. MD9923)

Dear Mr. Pardee:

By letter dated October 9, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML082890539), AmerGen Energy Company, LLC. (the licensee, now Exelon Generation Company, LLC) submitted a license amendment request regarding proposed changes to the technical specifications to reflect steam generator replacement for Three Mile Island Nuclear Station, Unit 1 (TMI-1).

The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information.

The questions were sent via electronic transmission on February 10, 2009, to Ms.

Wendi Croft of your staff. 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.

The questions were discussed in a teleconference with your staff on February 25, 2009, where clarifications were made to the questions. It was agreed that a response would be submitted within 30 days of the date of this letter.

Please contact me at 301-415-2833, if you have any questions.

Sincerely, /&tJ td i 1,L<.<1( roi\ Peter Bamford, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-289

Enclosure:

As stated cc: Distribution via Listserv UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 REQUEST FOR ADDITIONAL INFORMATION THREE MILE ISLAND, UNIT 1 REPLACEMENT STEAM GENERATOR LICENSE AMENDMENT DOCKET NO. 50-289 By letter dated October 9,2008, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML082890539), AmerGen Energy Company, LLC (the licensee, now Exelon Generation Company, LLC) submitted a license amendment request regarding proposed changes to the technical specifications (TSs) to reflect steam generator (SG) replacement for Three Mile Island Nuclear Station, Unit 1 (TMI-1).

The Nuclear Regulatory Commission (NRC) staff has been reviewing the submittal and has determined that additional information is needed to complete its review. Please confirm that the 40 percent through-wall tube repair criterion remains acceptable for the replacement SGs and discuss how it was determined.

Specifically, please indicate if it was determined in accordance with Regulatory Guide 1.121, "Bases for Plugging Degraded PWR [pressurized water reactor] Steam Generator Tubes." If the criterion was not established in accordance with RG 1.121, provide the technical basis for the methodology used to develop the tube repair criterion. For the replacement SGs, please provide the tube size (diameter and wall thickness).

Additionally, please specify the design and operating differential pressure across the tubes. You have proposed to increase your TS limit on primary-to-secondary leakage to 150 gallons per day per SG. In addition, you have indicated that your bases would be modified accordingly.

Your current TS 6.19(b)(2) indicates that the safety analysis assumes a leakage volume or rate of primary-to-secondary leakage from all SGs depending on the specific accident analyses. The limit on primary-to-secondary leakage is primarily based on two considerations: (1) limit the frequency of tube rupture and (2) limit the radiological dose to the public and control room operators.

Given the current wording in TS 6.19(b)(2), which implies that at least one accident analyses assumes a leakage volume, please confirm that your current NRC-approved design and licensing basis accident analyses that assume primary-to-secondary leakage (e.g., steam line break, locked rotor, control rod ejection, etc.) assume that at least 150 gallons per day per SG primary-to-secondary leakage is occurring.

In addition, please provide the reference that incorporated the volume criteria in your design and licensing basis and confirm that this analysis was NRC approved and remains applicable to the new SGs.

Enclosure March 6, 2009 Mr. Charles Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 THREE MILE ISLAND NUCLEAR STATION, UNIT 1 -

REQUEST FOR ADDITIONAL INFORMATION REGARDING REPLACEMENT STEAM GENERATOR LICENSE AMENDMENT (TAC NO. MD9923)

Dear Mr. Pardee:

By letter dated October 9, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML082890539), AmerGen Energy Company, LLC. (the licensee, now Exelon Generation Company, LLC) submitted a license amendment request regarding proposed changes to the technical specifications to reflect steam generator replacement for Three Mile Island Nuclear Station, Unit 1 (TMI-1).

The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information.

The questions were sent via electronic transmission on February 10, 2009, to Ms. Wendi Croft of your staff. 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.

The questions were discussed in a teleconference with your staff on February 25,2009, where clarifications were made to the questions. It was agreed that a response would be submitted within 30 days of the date of this letter.

Please contact me at 301-415-2833, if you have any questions.

Sincerely, Ed Miller fori Peter Bamford, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.

50-289

Enclosure:

As stated cc: Distribution via Listserv DISTRIBUTION:

PUBLIC RidsOgcRp Resource LPLI-2 R/F RidsAcrsAcnw_MailCTR Resource RidsNrrPMPBamford Resource RidsNrrDciCsgb Resource RidsRgn1 MailCenter Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl1-2 Resouce AObodoako, NRR RidsNrrLAABaxter Resource ADAMS Accession Number' ML090300488

• concurrence via memo OFFICE LPLI-2/PM LPLI-2/LA AFPB/BC LPLI-2/BC NAME PBamford ABaxter AHiser

• HChernoff DATE 2/25/09 2126/09 01/1612009 316/09 OFFICIAL RECORD COPY