ML100630260

Request for Additional Information Related to Salem Nuclear Generating Station, Unit 1 and 2 License Renewal Application, Aging Management Program B2.16 Thermal Aging Embrittlement of Cast Austenitic Stainless Steel

ML100630260
Person / Time
Site:	Salem
Issue date:	05/14/2010
From:	Ashley D J License Renewal Projects Branch 1
To:	Joyce T Public Service Enterprise Group
Ashley Donnie, NRC/NRR/DLR/RPB1
References
Download: ML100630260 (10)

Text

May 14, 2010 Mr. Thomas Joyce President and Chief Nuclear Officer PSEG Nuclear LLC P.O. Box 236 Hancocks Bridge, NJ 08038

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION RELATED TO SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION, AGING MANAGEMENT PROGRAM B2.1.6 THERMAL AGING EMBRITTLEMENT OF CAST AUSTENITIC STAINLESS STEEL

Dear Mr. Joyce:

By letter dated August 18, 2009, as supplemented by letter dated January 23, 2009, Public Service Enterprise Group Nuclear, LLC, submitted an application pursuant to Title 10 of the Code of Federal Regulation Part 54 for renewal of Operating License Nos. DPR-70 and DPR-75 for Salem Nuclear Generating Station Units 1 and 2, respectively. The staff of the U.S. Nuclear Regulatory Commission (NRC or the staff) is reviewing this application in accordance with the guidance in NUREG-1800, "Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants." During its review, the staff has identified areas where additional information is needed to complete the review. The staff's requests for additional information are included in the Enclosure. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with John Hufnagel and other members of your staff during a telephone call on April 20, 2010, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me by telephone at 301-415-3191 or by e-mail at donnie.ashley@nrc.gov. Sincerely,

/RA by Bennett Brady for/

Donnie J. Ashley, Senior Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-272 and 50-311

Enclosure:

As stated cc w/encl: See next page

ML100630260 OFFICE LA:DLR PM:DLR:RPB1 BC:DLR:RPB1 PM:DLR:RPB1 NAME Y.Edmonds D. Ashley (BBrady for) B. Pham D. Ashley (BBrady for) DATE 05/12/10 0512/10 05/14/10 05/14/10 Letter to T. Joyce from D. Ashley dated May 14, 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION RELATED TO SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION, AGING MANAGEMENT PROGRAM B2.1.6 THERMAL AGING EMBRITTLEMENT OF CAST AUSTENITIC STAINLESS STEEL DISTRIBUTION

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BPham DAshley CEccleston REnnis CSanders MModes, RI DKern, RI JBrand, RI RConte, RI RBellamy, RI MMcLaughlin, RI Salem Nuclear Generating Station, Units 1 and 2 cc: Mr. Robert Braun Senior Vice President Nuclear PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038

Mr. Carl Fricker Station Vice President - Salem PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Mr. Michael Gallagher Vice President - License Renewal Projects Exelon Nuclear LLC 200 Exelon Way Kennett Square, PA 19348

Mr. Ed Eilola Plant Manager - Salem PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038

Mr. Brian Booth Director Nuclear Oversight PSEG Nuclear P.O. Box 236 Hancocks Bridge, NJ 08038 Mr. Jeffrie J. Keenan, Esquire Manager - Licensing PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Senior Resident Inspector Salem Nuclear Generating Station U.S. Nuclear Regulatory Commission Drawer 0509 Hancocks Bridge, NJ 08038 Mr. Ali Fakhar Manager, License Renewal PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038

Mr. William Mattingly Manager - Salem Regulatory Assurance PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Township Clerk Lower Alloways Creek Township Municipal Building, P.O. Box 157 Hancocks Bridge, NJ 08038 Mr. Paul Bauldauf, P.E., Asst. Director Radiation Protection Programs NJ Department of Environmental Protection and Energy, CN 415 Trenton, NJ 08625-0415

Mr. Brian Beam Board of Public Utilities 2 Gateway Center, Tenth Floor Newark, NJ 07102

Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406

Mr. Gregory Sosson Director Corporate Engineering PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038 Mr. Paul Davison Vice President, Operations Support PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038

Salem Nuclear Generating Station, Units 1 and 2 cc: Ms. Christine Neely Director - Regulator Affairs PSEG Nuclear LLC One Alloway Creek Neck Road Hancocks Bridge, NJ 08038

Mr. Earl R. Gage Salem County Administrator Administration Building 94 Market Street Salem, NJ 08079

ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION SALEM LICENSE RENEWAL APPLICATION AGING MANAGEMENT PROGRAM B2.1.6 THERMAL AGING EMBRITTLEMENT OF CAST AUSTENITIC STAINLESS STEEL RAI B.2.1.6-1

Background

The Program Description section of B2.1.6 states that the Thermal Aging Embrittlement of Cast Austenitic Stainless Steel (CASS) program is a new program that manages CASS components.

Request: (a) Identify the scope of the program by listing piping systems and associated components such as vessels, pumps, and valves that are covered under the subject CASS AMP.

(b) On page A-55 of the LRA, the applicant stated that AMP B2.1.6 will be implemented prior to the period of extended operation. Provide the month and year or refueling outage of the implementation.

RAI B.2.1.6-2

Background

The Program Description section of B2.1.6 states that the Salem ASME Section XI Inservice inspection (ISI) program, Subsection IWB, IWC, and IWD program is augmented by the implementation of the subject Thermal Aging Embrittlement of CASS aging management program. The NRC staff notes that the ASME Section XI ISI program requires inspection of only a limited number of welds in a piping system once every 10 years. Ultrasonic testing is not reliable and not qualified in detecting flaws in CASS components. Surface and visual examinations detect flaws only after degradation has occurred.

Issue: It is not clear to the NRC staff how the ASME Section XI ISI program can detect thermal aging embrittlement in the CASS components in time to prevent component failures.

Request: Discuss exactly how the ASME ISI program is augmented and enhanced as a result of implementing the CASS AMP (e.g., discuss any changes to the ASME ISI program as a result of the CASS AMP in terms of inspection frequency and inspection methods).

RAI B.2.1.6-3

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Background===

The Program Description section of B2.1.6 states that thermal aging embrittlement will be managed through either an enhanced volumetric inspection or a component-specific flaw tolerance evaluation.

Request: (a) Discuss whether thermal aging embrittlement of CASS material will be managed by the enhanced volumetric inspection or by the flaw tolerance evaluation. If the flaw tolerance evaluation would be used, discuss how the flaw tolerance evaluation will be implemented during the period of extended operation to ensure the structural integrity of the CASS components.

(b) On April 15, 2010, the NRC staff audited the flaw tolerance evaluation and requests for additional information on specific technical issues as shown below. However, describe the flaw tolerance evaluation in detail.

(c) Discuss how the CASS components will be inspected under the risk-informed ISI program at Salem units considering the requirements of the CASS AMP B2.1.6 (e.g., whether the CASS AMP will increase the inspection frequency of the CASS components in the risk-informed ISI program and whether thermal aging embrittlement will be a degradation mechanism considered in the risk-informed ISI program).

RAI B.2.1.6-4

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Background===

The Program Description section of B2.1.6 references the requirements of ASME Code Case N-481 regarding inspection of pump casings and valve bodies. Also, the GALL report (NUREG-1801),Section XI.M12, Thermal Aging Embrittlement of Cast Austenitic Stainless Steel, states that Code Case N-481 is adequate to use for inspecting all pump casings and valve bodies. The NRC approved Code Case N-481 in Regulatory Guide (RG) 1.147, Revision

14. Issue: Code Case N-481 has been annulled as of March 28, 2004, and is not approved as indicated in RG 1.147, Revision 15, because it has been incorporated into the ASME Code,Section XI.

Request: Justify the use of Code Case N-481, or propose alternative examinations for pump casings and valve bodies as part of AMP B2.1.6.

RAI B.2.1.6-5

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Background===

The Program Description section of B2.1.6 states that "-Flaw tolerance evaluation for components with ferrite content up to 25 percent is performed according to IWB-3640 for submerged arc welds (SAW)-"

Issue: It is not clear to the NRC that if a CASS component has ferrite content greater than 25 percent or if a CASS component is joined to another component by a welding process other than SAW, how the CASS component will be analyzed in the flaw tolerance evaluation.

Request: (a) Clarify the intent of the above statement.

(b) Discuss whether Salem units have CASS components with ferrite content greater than 25 percent.

(c) Confirm that the flaw tolerance evaluation was prepared for and is applicable only to the CASS components under the subject aging management program.

RAI B.2.1.6-6

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Background===

The Operating Experience section of B2.1.6 cites an operating experience of cracking in impeller vanes of reactor coolant pumps attributed to thermal aging embrittlement.

Request: Discuss whether the impeller vane degradation is applicable to the Salem units and whether the impeller vanes at Salem units have been inspected.

On April 15, 2010, the staff audited Westinghouse report, "Flaw Tolerance Evaluation for susceptible CASS Reactor Coolant Piping Components in Salem Units 1 and 2," LTR-PAFM-09-60, in the Westinghouse Satellite Office in Rockville, Maryland. This audit is part of the staff's review of Aging Management Program B2.1.6, "Thermal Aging Embrittlement of Cast Austenitic Stainless Steel (CASS)," for the Salem license renewal application. To complete its review, the staff requests the following information regarding the subject Westinghouse flaw tolerance evaluation:

RAI B.2.1.6-7

Background

Pages 7, 8, and 9 showed residual stresses at the reactor vessel inlet nozzle safe end-to-cold leg elbow weld regions as a result of the mechanical stress improvement process (MSIP).

Request: (a) Discuss how the residual stresses are factored in the allowable flaw size calculation for the cold leg elbow.

(b) Identify the CASS elbows in the piping systems covered under the aging management program B2.1.6 in each unit that are affected by the MSIP.

RAI B.2.1.6-8

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Background===

Figures 6-1 to 6-6 show flaw tolerance curves up to 40 years.

Request: Explain why the flaw tolerance curves for 60 years were not generated.

RAI B.2.1.6-9

Background

Table 6-1 shows acceptable initial flaw size for CASS elbows.

Request: If a flaw is detected in a CASS elbow that exceeds the acceptable initial flaw size, discuss how the flaw would be dispositioned.

RAI B.2.1.6-10

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Background===

Table 6-1 provides the allowable final flaw sizes. Page 11, third paragraph, states that the allowable flaw sizes were calculated using Z factors in accordance with the ASME code,Section XI, IWB-3640.

Request: Describe in detail how the allowable flaw sizes were calculated.

RAI B.2.1.6-11 Request: (a) Confirm that for the fatigue crack growth calculation, the flaw growth rate for the PWR water environment was used.

(b) Discuss whether the flaw growth rate used in the calculation is consistent with the flaw growth rate in the ASME Code,Section XI, Appendix C. If it is not, provide justification.