ML14083A247

Watts Bar Nuclear Plant, Unit 1, Review of Reactor Vessel Materials Surveillance Program - Revised Surveillance Capsule Withdrawal Schedule (TAC No. MF3162)

ML14083A247
Person / Time
Site:	Watts Bar
Issue date:	03/27/2014
From:	Andrew Hon Plant Licensing Branch II
To:	Shea J W Tennessee Valley Authority
Hon A
References
TAC MF3162
Download: ML14083A247 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 27, 2014 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3D-C Chattanooga, TN 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNIT 1 -REVIEW OF REACTOR VESSEL MATERIALS SURVEILLANCE PROGRAM-REVISED SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE (TAC NO. MF3162)

Dear Mr. Shea:

By letter dated November 22, 2013, as supplemented by letters dated February 21, 2014, and March 10, 2014, Tennessee Valley Authority (TVA) requested approval of proposed changes to the reactor vessel surveillance capsule withdrawal schedule for the Watts Bar Nuclear Plant, Unit 1 (WBN-1). The proposed changes were submitted pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR) Part 50, Appendix H,Section III.B.3, which requires that: (1) withdrawal schedules be submitted, as specified in 10 CFR 50.4, and (2) the proposed schedule must be approved by the Nuclear Regulatory Commission (NRC) prior to implementation. The NRC staff has reviewed TVA's submittals and concludes that the changes to the reactor pressure vessel surveillance capsule withdrawal schedule for WBN-1 is acceptable for implementation and satisfied the requirements of 10 CFR Part 50, Appendix H. The NRC staff's evaluation is enclosed. Please contact me at (301) 415-8480 if you have any questions. Docket No. 50-390

Enclosure:

Safety Evaluation cc w/enclosure: Distribution via Listserv Sincerely, Andrew Han, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REVISION TO REACTOR VESSEL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE

1.0 INTRODUCTION

WATTS BAR NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-390 By letter dated November 22, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13333A 165), Tennessee Valley Authority (TVA or the licensee) requested approval of proposed changes to the reactor vessel surveillance capsule withdrawal schedule for the Watts Bar Nuclear Plant, Unit 1 (WBN-1). Also, in response to a Request for Additional Information (RAI), the licensee provided additional clarification by letters dated February 21, 2014 (ADAMS Accession No. ML 14056A290) and March 10, 2014 (ADAMS Accession No. ML 14070A162). The proposed changes were submitted pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix H,Section III.B.3, which requires that: (1) withdrawal schedules be submitted, as specified in 10 CFR Part 50.4, and (2) the proposed schedule must be approved by the Nuclear Regulatory Commission (NRC) prior to implementation.

2.0 REGULATORY EVALUATION

2.1 Section 50.60 of Part 50 of 10 CFR and Appendix H to 10 CFR Part 50 The NRC has established requirements and criteria in 10 CFR 50.60 for protecting the reactor vessels (RVs) of U.S. light-water reactors (LWRs) against fracture. The rule requires LWRs to meet the RV materials surveillance program requirements set forth in Appendix H to 10 CFR Part 50. Appendix H to 10 CFR Part 50 provides the NRC staff's criteria for the design and implementation of RV material surveillance programs for operating LWRs. The rule, in part, requires RV surveillance program designs and withdrawal schedules to meet the requirements of the edition of American Society for Testing and Materials (ASTM) Standard Practice E185, "Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels," which is current on the issue date of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code to which the RV was purchased, although later editions of ASTM E185 may be used inclusive of the 1982 Edition of ASTM E185 (ASTM E185-82). The rule also requires proposed RV surveillance programs to be submitted to the NRC and approved prior to implementation. The applicable criteria in ASTM E 185-82 are discussed below. Enclosure Table 1 of ASTM E 185-82 requires that either a minimum of three, four, or five surveillance capsules be removed from the RVs, based on the limiting amount of RT NDT shift (limiting b.RT NDT) that is projected to occur at the clad-vessel interface location of the RV at the end-of-licensed plant life (EOL). ASTM E185-82 establishes the following criteria for determining the minimum number of capsules that are to be removed in accordance with a withdrawal schedule and the number of capsules that are to be tested: 1. For plants with projected b.RT NDT less than or equal to 100 oF (degree Fahrenheit) or 56 oc (degree Celsius), three capsules are required to be removed from the RV and the first two capsules are required to be tested (for dosimetry, tensile-ductility, Charpy-V impact toughness, and alloying chemistry). 2. For plants with projected b.RT NDT greater than 100 oF (56° C) but less than or equal to 200 oF (111 °C), four surveillance capsules are to be removed from the RV and the first three capsules are required to be tested. 3. For plants with projected b.RT NDT above 200 °F (111 °C), five surveillance capsules are required to be removed from the RV and the first four capsules are required to be tested. ASTM E185-82 also provides specific criteria for removal of surveillance capsules. The removal times are based on criteria that the surveillance capsules be removed after a certain amount of power operation has elapsed or at various times when the RV shell is projected to achieve certain levels of neutron fluence. The intent of the Standard Practice is to achieve a set of testing data over a range of neutron fluences for the RV that bounds the current life of the plant. Of key importance are the removal criteria for the second to last and final capsules required for capsule withdrawal. For the second-to-last required capsule in a withdrawal schedule, ASTM E 185-82 requires that the capsules be pulled at either 15 effective full-power years (EFPYs) or at the time when the capsule is equivalent to the limiting fluence projected for the clad-based metal interface of the RV at EOL, whichever time comes first. For the final capsule that is required for removal, ASTM E185-82 requires that the capsule be removed at a time when the neutron fluence projected for the capsule is between the limiting fluence value projected for the RVs at the EOL and two times that value. 2.2 NRC Administrative Letter (AL)97-004 and NRC Memorandum and Order CLI-96-13 On September 30, 1997, the NRC issued AL 97-004 to all holders of operating licenses for domestic nuclear power plants (with the exception of those who have ceased operations of their facilities or have certified that fuel has been permanently removed from the reactor). In this AL, the NRC staff summarized the Commission's decision promulgated in Commission Memorandum and Order CLI-96-13, which was issued "In the Matter of the Cleveland Electric Illuminating Company (Perry Nuclear Power Plant, Unit 1 )" on December 6, 1996. In this Memorandum and Order, the Commission found that, while 10 CFR Part 50, Appendix H, 111.8.3 requires prior NRC approval for all withdrawal schedule changes, only certain changes require the NRC staff to review and approve the changes through the NRC's license amendment process (10 CFR 50.90 process). Specifically, only those changes that are not in conformance with the ASTM standard referenced in 10 CFR Part 50, Appendix H (i.e., ASTM E-185,) are required to be approved through the license amendment process, whereas changes that are determined to conform to the ASTM standard only require that the staff document its review and verification of such conformance. 2. 3 GALL Report Guidelines The licensee may apply for license renewal with an additional 20 year period of extended operation (PEO) based on NUREG-1801, Generic Aging Lessons Learned (GALL) Report.Section XI.M31 of the current GALL Report (Revision 2) includes recommended changes to the surveillance capsule withdrawal schedule that depends on whether the program for the original license period includes a capsule that bounds the projected maximum fluence for the additional 20-year PEO. If no capsule has been pulled that would bound the fluence for the PEO, the GALL Report would allow the licensee to delay withdrawal and testing of the final capsule until the fluence exceeds the projected maximum fluence for the additional 20-year PEO. The GALL Report, Revision 2, also includes detailed guidance on the disposition of all pulled and tested samples or capsules placed in storage. If and when WBN-1 applies for license renewal, the plant will have to address the GALL Report version that is current at that time.

3.0 TECHNICAL EVALUATION

3.1 Changes Proposed to the Withdrawal Schedule for WBN-1 For WBN-1, the licensee is applying the requirements of ASTM E 185-82 as its basis for meeting the RV surveillance capsule withdrawal requirements of 10 CFR Part 50, Appendix H. With respect to the EOL, the NUREG-1511, "Reactor Pressure Vessel Status Report," December 1994, lists the WBN-1 RV with a limiting value of 172 °F. As stated above in paragraph 2.1' since the NOT value is greater than 100 °F, but less than 200 °F, ASTM E185-82 requires that the licensee, at a minimum, remove four capsules from the reactor during the licensed operating period. The licensee's November 22, 2013, letter provides the proposed revision to the RV surveillance capsule withdrawal schedule for WBN-1. The letter indicated that Capsules U, W, X, and Z were removed from WBN-1 and tested. The results are summarized in Westinghouse Report WCAP-16760-NP, "Analysis of Capsule Z from the Tennessee Valley Authority Watts Bar, Unit 1 Reactor Vessel Radiation Surveillance Program," dated November 2007. The neutron fluences reported for capsules U, W, X, and Z at the time of withdrawal are 4.47x1018 n/cm2, 1.08x1019 n/cm2, 1.71x1019 n/cm2, and 2.40x1019 n/cm2, respectively, as reported in WCAP-16760-NP. Based on the data provided by the licensee, the staff notes that the withdrawal schedule for Capsules U, W, X, and Z is consistent with the guidelines of ASTM E-185-82 for the four capsules required to be withdrawn for the current 40-year license period. The licensee indicated in its November 22, 2013, letter that in addition to the four capsules that have already been withdrawn and tested, that one standby capsule (Capsule V) would be removed from the WBN-1 RV at approximately 25.9 EFPYs, with a projected fluence of 6.02x1 019 n/cm2. The staff concludes that the withdrawal schedule for Capsule Vis consistent with the guidelines of the GALL Report, Revision 2, for the extra capsule required to be withdrawn to cover the period of extended operation.

The licensee also indicated in the November 22, 2013, letter that, given the proposed change to the withdrawal schedule, it will still have one standby capsule (Capsule Y) that will remain inserted in the RV on standby until needed to fulfill potential future requirements. This is not a change from the current withdrawal schedule. During the review, the staff noted that the lead factors in the table from Attachment 2 are not consistent with the text of the enclosure. In response to an RAI, the licensee clarified by letter dated February 14, 2014, that the lead factors in the table of Attachment 2 are correct and in the March 10, 2014, letter, changed the text of the enclosure to the November 22, 2013, letter to make the text consistent with the table. The staff has reviewed the revised text and finds the description in the text is consistent with the information in the table. The staff's concern expressed in the RAI is resolved. In summary, the licensee has proposed a change to the surveillance capsule withdrawal schedule for WBN-1. The proposed schedule will withdraw Capsule V when the fluence on the capsule is approximately 6.02x1 019 n/cm2, which is less than 2x the projected 60-year inner diameter fluence for the WBN-1 RV. The change does not affect Capsule Y, which will remain in the vessel for future use. Therefore, the licensee's proposed change to the surveillance capsule withdrawal schedule is based on the requirements of the ASTM E 185-82, as required by Appendix H to 10 CFR Part 50, and also meets the requirements of GALL Report Section XI.M31. Since the licensee's proposed change is in conformance with ASTM 185 referenced in 10 CFR Part 50, Appendix H, the change is not required to be approved through the license amendment process as discussed above in paragraph 2.2.

4.0 CONCLUSION

The NRC staff has reviewed TVA's proposed withdrawal schedules for WBN-1 and has determined that the changes to the schedule will continue to meet the RV surveillance capsule withdrawal schedule criteria in ASTM E185-82, and will be in compliance with 10 CFR Part 50, Appendix H, AL 97-004, and GALL Report Section XI.M31. The staff, therefore, concludes that the RV withdrawal schedule, as proposed in the licensee's November 22, 2013, letter and modified by the March 10, 2014, letter, is acceptable for implementation. Principal Contributor: P. Purtscher Date: March 27, 2014 March 27, 2014 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3D-C Chattanooga, TN 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNIT 1-REVIEW OF REACTOR VESSEL MATERIALS SURVEILLANCE PROGRAM-REVISED SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE (TAC NO. MF3162)

Dear Mr. Shea:

By letter dated November 22, 2013, as supplemented by letters dated February 21, 2014, and March 10, 2014, Tennessee Valley Authority (TVA) requested approval of proposed changes to the reactor vessel surveillance capsule withdrawal schedule for the Watts Bar Nuclear Plant, Unit 1 (WBN-1 ). The proposed changes were submitted pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR) Part 50, Appendix H, Section lli.B.3, which requires that: (1) withdrawal schedules be submitted, as specified in 10 CFR 50.4, and (2) the proposed schedule must be approved by the Nuclear Regulatory Commission (NRC) prior to implementation. The NRC staff has reviewed TVA's submittals and concludes that the changes to the reactor pressure vessel surveillance capsule withdrawal schedule for WBN-1 is acceptable for implementation and satisfied the requirements of 10 CFR Part 50, Appendix H. The NRC staff's evaluation is enclosed. Please contact me at (301) 415-8480 if you have any questions. Docket No. 50-390

Enclosure:

Safety Evaluation Sincerely, IRA/ Andrew Hon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation cc w/enclosure: Distribution via Listserv DISTRIBUTION: RidsNrrDorllpl2-2 RidsNrrPMWattBar1 PUBLIC RidsNrrDoriDpr LPL2-2 R/F RidsRg n2Mai1Center RidsAcrsAcnw _MaiiCTR RidsNrrLABCiayton RidsNrrDeEvib PPurtscher, NRR ADAMS A ccess1on N o.: M L 14083A24 7 *b )_"j_memo ML 14077A254 OFFICE LPLII-2/PM LPLII-2/LA NRR/DE/EVI B/BC* LPLII-2/BC LPLII-2/PM NAME AHon BCiayton SRosenburg JQuichocho AHon DATE 3/25/14 3/25/14 03/20/14 3/27/14 3/27/14 OFFICIAL RECORD COPY