ML070520461
| ML070520461 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/27/2007 |
| From: | Milano P NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Koehl D Nuclear Management Co |
| P. Milano X1457 | |
| References | |
| TAC MD2583 | |
| Download: ML070520461 (5) | |
Text
February 27, 2007 Mr. Dennis Koehl Site Vice President Point Beach Nuclear Plant Nuclear Management Company, LLC 6610 Nuclear Road Two Rivers, WI 54241-9516
SUBJECT:
POINT BEACH NUCLEAR PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO STEAM GENERATOR PROGRAM (TAC NO. MD2583)
Dear Mr. Koehl:
By letter dated July 11, 2006, as supplemented on January 19, 2007, Nuclear Management Company, LLC (NMC) requested an amendment to the Technical Specifications (TSs) for the Point Beach Nuclear Plant, Unit 1. The proposed amendment would revise TS 5.5.8, Steam Generator (SG) Program, to change the repair criteria for the portion of the SG tubes within the hot-leg region of the tubesheet for a single operating cycle following Refueling Outage 30.
The Nuclear Regulatory Commission (NRC) staff is reviewing your submittals and has determined that additional information is required to complete its review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on February 21, 2007, it was agreed that NMC would provide a response within 30 days of the date of this letter.
The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1457.
Sincerely,
/RA/
Patrick D. Milano, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-266
Enclosure:
Request for Additional Information cc w/encl: See next page
ML070520461 OFFICE LPL3-1/PM LPL3-1/LA CSGB/BC LPL3-1/BC NAME PMilano:ca THarris AHiser LRaghavan DATE 02/26 /07 02/23/07 02/12/07 02/27/07
Point Beach Nuclear Plant, Units 1 and 2 cc:
Jonathan Rogoff, Esquire Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Mr. F. D. Kuester President & Chief Executive Officer WE Generation 231 West Michigan Street Milwaukee, WI 53201 Regulatory Affairs Manager Point Beach Nuclear Plant Nuclear Management Company, LLC 6610 Nuclear Road Two Rivers, WI 54241 Mr. Ken Duveneck Town Chairman Town of Two Creeks 13017 State Highway 42 Mishicot, WI 54228 Chairman Public Service Commission of Wisconsin P.O. Box 7854 Madison, WI 53707-7854 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351 Resident Inspector's Office U.S. Nuclear Regulatory Commission 6612 Nuclear Road Two Rivers, WI 54241 Mr. Jeffery Kitsembel Electric Division Public Service Commission of Wisconsin P.O. Box 7854 Madison, WI 53707-7854 Nuclear Asset Manager Wisconsin Electric Power Company 231 West Michigan Street Milwaukee, WI 53201 Michael B. Sellman President and Chief Executive Officer Nuclear Management Company, LLC 700 First Street Hudson, MI 54016 Douglas E. Cooper Senior Vice President & Chief Nuclear Officer Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Site Director of Operations Nuclear Management Company, LLC 6610 Nuclear Road Two Rivers, WI 54241
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST STEAM GENERATOR PROGRAM NUCLEAR MANAGEMENT COMPANY, LLC POINT BEACH NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-266 By letter dated July 11, 2006, as supplemented on January 19, 2007 (Agencywide Documents Access and Management System Accession Nos. ML062050338 and ML070220084, respectively), Nuclear Management Company, LLC (NMC) submitted a proposed amendment to the Technical Specifications (TSs) for the Point Beach Nuclear Plant, Unit 1. The proposed changes would revise TS 5.5.8, Steam Generator (SG) Program, to change the repair criteria for the portion of the tubes within the hot-leg region of the tubesheet for a single operating cycle following Refueling Outage 30. The proposed amendment defines a distance downward into the hot-leg tubesheet, below which flaws may remain in service regardless of size. As a result, tube inspection within the hot-leg region would be required only within 17 inches of the top of the tubesheet.
Background For Items 1 and 2 Argonne National Laboratory (ANL), under contract to the Nuclear Regulatory Commission (NRC), is performing generic studies relating to the leakage behavior of SG tube-to-tubesheet joints (T-TS joints) under postulated severe accident conditions. As part of this work, ANL benchmarked its finite element model of the T-TS joint against pullout and leakage tests carried out by Westinghouse (WCAP-15932-P) on tube-to-collar joint specimens (to simulate T-TS joints) for the Callaway Plant. While performing this benchmarking study, ANL observed that the distribution of contact pressure (between the tube and tubesheet) caused by differential thermal expansion effects and by the roll expansion process (calculated indirectly by Westinghouse based on the test results), is much different than that calculated by ANL. ANL states that this may be due to an incorrect choice of thermal expansion coefficients for the tubesheet collar specimens used in the Westinghouse tests. The test specimen collars were made from cold-worked 1018 steel instead of the actual tubesheet material, which is forged SA-508 steel. Although the yield strengths of these two materials are comparable, their coefficients of thermal expansion are somewhat different. ANL believes the ANL results differ from the Westinghouse results because Westinghouse assumed thermal expansion properties of SA-508 rather than 1018 steel when analyzing their test results.
The Westinghouse tests for Callaway are similar to those performed in support of the proposed amendment for Point Beach 1. The July 11, 2006, NMC letter, enclosed Westinghouse report LTR-CDME-05-201-P, Revision 1, Limited Inspection of the Steam Generator Tube Portion Within the Tubesheet at Point Beach Unit 1. The NRC staff notes that the pullout and leakage tests described in that report also utilized collar specimens fabricated from 1018 steel and not the SA-508 steel from which the Point Beach 1 tubesheets were actually fabricated.
On the basis of the tests, the NRC staff requests the following additional information in order to complete its review.
1.
Provide any comments on ANLs observation regarding the possibility of an incorrect choice of thermal expansion coefficient for the tubesheet collar specimens used in the Westinghouse tests in terms of how it may apply to Point Beach 1. If you should disagree with the ANL observations pertaining to Callaway or if you believe the ANL observations are not relevant to Point Beach 1, provide an explanation.
2.
If there is a problem with the assumed values of thermal expansion coefficient, describe the problem and provide any necessary corrections to Westinghouse report LTR-CDME-05-201-P, Revision 1. (To support timely completion of the NRC staffs review, the items of highest priority to the staff are any revisions to Figures 5-10, Tables A.2-1 and A.2-2, and Figures A.1-2 and A.1-3.)
3.
Provide any revisions or corrections to LTR-CDME-05-201-P, Revision 1, to reflect any new Westinghouse crevice pressure test data and analyses that may be relevant to tube repair criteria and inspection in the tubesheet region at Point Beach 1. (To support timely completion of the staffs review, the items of highest priority to the staff are any revisions to Figures 5-10, Tables A.2-1 and A.2-2, and Figures A.1-2 and A.1-3.)