ML17167A083
| ML17167A083 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/28/2017 |
| From: | Thomas Wengert Plant Licensing Branch IV |
| To: | Entergy Operations |
| Wengert T, 301-415-4037 | |
| References | |
| CAC MF8154 | |
| Download: ML17167A083 (7) | |
Text
ANO Site Vice President Arkansas Nuclear One Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 28, 2017
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 2 - REVIEW OF COMMITMENT SUBMITTAL FOR LICENSE RENEWAL REGARDING NICKEL-BASED ALLOY AGING MANAGEMENT PROGRAM PLAN (CAC NO. MF8154)
Dear Sir or Madam:
By letter dated July 18, 2016, Entergy Operations, Inc. (Entergy, the licensee) submitted a document titled "Alloy 600 Aging Management Program Plan," for Arkansas Nuclear One, Unit 2 (AN0-2) to the U.S. Nuclear Regulatory Commission (NRC) for review and approval.
The licensee submitted the AN0-2 Alloy 600 Aging Management Program (AMP) Plan for NRC review and approval in accordance with license renewal Commitment No. 1, documented in NUREG-1828, "Safety Evaluation Report Related to the License Renewal of the Arkansas Nuclear One, Unit 2," Appendix A, dated June 2005. During the NRC staff's review of Entergy's AN0-2 license renewal application, the licensee provided the commitment to address the NRC staff's concerns regarding the licensee's plan to manage the aging effects of components fabricated from nickel-based alloys (i.e., Alloy 600, Alloy 690, and welds with Alloy 82/182 and Alloy 52/152 filler metals) in the reactor coolant system that are not addressed by the licensee's Reactor Vessel Head Penetration Inspection and Steam Generator Integrity Programs during the period of extended operation.
The NRC staff reviewed the information in the licensee's submittal and determined that the licensee has fulfilled Commitment No. 1 for license renewal and demonstrated that the Alloy 600 AMP Plan provides reasonable assurance that aging components under consideration will be adequately managed.
If you have any questions, please contact me at (301) 415-4037 or by e-mail at Thomas.Wengert@nrc.gov.
Docket No. 50-368
Enclosure:
Staff Assessment cc w/encl: Distribution via Listserv Sincerely,
~--"~er-.: r+-
Thomas J. Wengert, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 STAFF ASSESSMENT BY THE OFFICE OF NUCLEAR REACTOR REGULATION LICENSE RENEWAL COMMITMENT SUBMITTAL OF NICKEL-BASED ALLOY AGING MANAGEMENT PROGRAM ENTERGY OPERATIONS, INC.
ARKANSAS NUCLEAR ONE, UNIT 2 DOCKET NO. 50-368
1.0 INTRODUCTION AND BACKGROUND
By letter dated July 18, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16200A131), Entergy Operations, Inc. (Entergy, the licensee),
submitted a document titled "Alloy 600 Aging Management Program Plan," for Arkansas Nuclear One, Unit 2 (AN0-2) to the U.S. Nuclear Regulatory Commission (NRC) for review and approval.
The licensee submitted the AN0-2 Alloy 600 Aging Management Program (AMP) Plan for NRC review and approval in accordance with the license renewal commitment documented in NUREG-1828, "Safety Evaluation Report Related to the License Renewal of the Arkansas Nuclear One, Unit 2," dated June 2005 (ADAMS Accession No. ML051730233). During the license renewal of AN0-2, the licensee provided the license renewal commitment to address the NRC staff's concerns related to how the licensee would manage the aging effects of components fabricated from nickel-based alloys (i.e., Alloy 600, Alloy 690, and welds with Alloy 82/182 and Alloy 52/152 filler metals) in the reactor coolant system that are not addressed by the licensee's Reactor Vessel Head Penetration Inspection and Steam Generator Integrity Programs during the period of extended operation (PEO).
At the time of license renewal for AN0-2, there were multiple initiatives by industry and NRC for managing nickel-based alloy cracking due to primary water stress corrosion cracking (PWSCC) in reactor pressure boundary components of pressurized water reactors (PWRs). Since AN0-2 is a PWR, and PWSCC of its nickel-based alloys could be applicable to its reactor pressure boundary components during the PEO, the licensee made a commitment to resubmit its Alloy 600 AMP for NRC review and approval prior to entering the PEO.
2.0 REGULATORY EVALUATION
By letter dated October 14, 2003 (ADAMS Accession No. ML032890492), Entergy submitted a license renewal application (LRA) for AN0-2. Title 10 of the Code of Federal Regulations (10 CFR) Part 54, "Requirements for Renewal of Operating Licenses for Nuclear Power Plants,"
Enclosure addresses the requirements for plant license renewal. Pursuant to 1 O CFR 54.21, "Contents of application-technical information," each application for license renewal must contain an integrated plant assessment (IPA).
The plant-specific IPA must identify and list those structures and components subject to an aging management review and demonstrate that the effects of aging (e.g., cracking, loss of material, loss of fracture toughness, dimensional changes, and loss of preload) will be adequately managed so that their intended functions will be maintained consistent with the current licensing basis (CLB) for the PEO as required by 10 CFR 54.29(a). In addition, 1 O CFR 54.21 (d) requires that the final safety analysis report (FSAR) supplement for the facility contain a summary description of AMPs and activities for managing the effects of aging, as well as time-limited aging analyses for the PEO.
By letter dated June 30, 2005 (ADAMS Accession No. ML051800757), the NRG issued Renewed Facility Operating License No. NPF-6 for AN0-2. The technical basis for the NRG staff's review and issuance of the renewed operating facility license is documented by NUREG-1828. As stated above, NUREG-1828 also documents the licensee's commitment regarding future activities to be completed by the licensee related to the aging management of nickel alloy components in the reactor coolant system, which are not addressed by the licensee's Reactor Vessel Head Penetration Inspection and the Steam Generator Integrity Programs.
Pursuant to 1 O CFR 54.21 (d), AN0-2 Safety Analysis Report, Section 18.1.1 includes a summary description of the licensee's Alloy 600 AMP. Additionally, License Condition 2.F of AN0-2 Renewed Facility Operating License No. NPF-6 states that AN0-2 shall complete certain future activities as described in its FSAR supplement, submitted pursuant to 1 O CFR 54.21 (d), prior to July 17, 2018 (i.e., the PEO).
During license renewal, the NRG staff reviewed the AN0-2 LRA in accordance with 10 CFR Part 54, and the guidance provided by NUREG-1800, "Standard Review Plan for the Review of License Renewal Applications for Nuclear Power Plants" (SRP-LR), dated July 2001 (ADAMS Accession Nos. ML012070391 and ML012070409). The latest revision of SRP-LR is NUREG-1800, Revision 2, dated December 201 O (ADAMS Accession No. ML103490036). As documented in Commitment No. 1 in NUREG-1828, Appendix A, the licensee committed to submit a description of its Alloy 600 AMP for NRG staff review and approval at least 24 months prior to AN0-2 entering its PEO. The PEO for AN0-2 will begin on July 18, 2018.
Based on the above, and subject to the following technical evaluation, the NRG staff concludes that the regulatory authority exists for the licensee to request and the NRG to review and approve the licensee's Alloy 600 AMP submittal for AN0-2. The scope of the staff's assessment is limited to the AN0-2 "Alloy 600 Aging Management Program," submitted by the licensee to satisfy the AN0-2 license renewal commitment.
3.0 TECHNICAL EVALUATION
3.1 Summary of Technical Information Provided by the Licensee In its submittal dated July 18, 2016, Entergy stated that, at the time of the license renewal of AN0-2, the license renewal guidance for AMPs was provided by NUREG-1801, "Generic Aging Lessons Learned (GALL) Report," Revision 0, dated July 2001 (ADAMS Accession Nos. ML012060392, ML012060514, ML012060539, and ML012060521). The licensee also stated that PWSCC in Alloy 600 materials is a current license term issue and that interaction between the NRC and the industry has been ongoing to develop a program to manage the effects of aging due to this mechanism. The licensee further stated that issues that are relevant to current plant operation are addressed by the existing regulatory process within the present license term, rather than deferred until the PEO. In addition, the licensee stated that the existing regulatory process provides assurance that aging effects caused by PWSCC of Alloy 600 materials are adequately managed during the PEO.
The licensee stated that its Alloy 600 AMP manages aging effects of nickel alloy components in the reactor coolant system that are not addressed by its Reactor Vessel Head Penetration Inspection and Steam Generator Integrity Programs. The licensee further stated that the program detects PWSCC by using the examination and inspection requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),
Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components."
The licensee's submittal addressed 1 O elements of the AN0-2 Alloy 600 AMP that are used to describe the AMP. These 10 attributes align with the 10 program elements in NUREG-1800, Revision 2, SRP-LR, Section A.1, Table A.1-1, used to describe an acceptable AMP. The licensee indicated that the program manages aging in accordance with current applicable inservice inspection requirements, including ASME Code Cases N-722-1, "Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 Materials,Section XI, Division 1 "; N-729-1, "Alternative Examination Requirements for PWR Reactor Vessel Upper Heads With Nozzles Having Pressure-Retaining Partial-Penetration WeldsSection XI, Division 1"; and N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation ActivitiesSection XI, Division 1," subject to the conditions stipulated in 1 O CFR 50.55a.
3.2 NRC Staff Assessment During its prior review of the AN0-2 LRA, the NRC staff evaluated AN0-2 Alloy 600 AMP elements 1 through 10 of the licensee's program with respect to the 1 O program elements recommended in NUREG-1801. Subsequently, the NRC staff found the program acceptable, as documented in Section 3.0.3.3.1 of NUREG-1828. Additionally, the staff's previous review of the "corrective actions," "confirmation process," and "administrative controls," program elements 7, 8 and 9, respectively, is documented in Section 3.0.4 of NUREG-1828. As discussed above, PWSCC of nickel alloys was an emerging issue for PWRs at the time of the license renewal of AN0-2. In response to the staff's requests for additional information on this emerging issue during license renewal, the licensee provided a commitment to submit the AN0-2, Alloy 600 AMP for NRC review and approval at least 24 months prior to AN0-2 entering the PEO (ADAMS Accession No. ML042660110).
On June 21, 2011, subsequent to the issuance of the renewed operating license to AN0-2, the NRC updated 1 O CFR 50.55a to require all licensees of PW Rs to augment their inservice inspection programs by implementing ASME Code Case N-722-1 and ASME Code Case N-770-1 with certain conditions.
As discussed above, 1 O CFR 50.55a specifies augmented inspection requirements for Alloy 600/82/182 components. These augmented inspections include the implementation of ASME Code Cases N-722-1, N-729-1, and N-770-1, subject to the conditions in 1 O CFR 50.55a.
In its review, the NRG staff confirmed that the licensee's program relies on the augmented inspection requirements specified in 1 O GFR 50.55a. The staff also noted that the licensee's program, which requires the performance of inservice inspection activities in accordance with 1 O GFR 50.55a, is also consistent with the current guidance provided in NUREG-1801, Revision 2.
In addition, the NRG staff evaluated the overall effectiveness of the licensee's program for managing the aging effects of its nickel-based alloy components during the PEO, as described below. Specifically, the staff reviewed the operating experience of the plant's nickel alloy components, including inspection results, to evaluate whether the program would maintain the intended functions of these components, consistent with the GLB during the PEO, in accordance with 1 O GFR 54.21 (a)(3).
The NRG staff noted that the licensee has replaced some nickel alloy components, performed full structural weld overlays, and has performed other mitigating activities at AN0-2. In addition, the licensee stated that plant-specific and industry operating experience suggest that mitigating activities and inspections performed in accordance with the program have been effective in identifying PWSGG.
The NRG staff reviewed this information against the acceptance criteria in SRP-LR Section A.1.2.3.10, which states in part that currently available operating experience applicable to the program, as well as consideration of future operating experience relating to the AMP, should be discussed. SRP-LR Section A.1.2.3.10 also states that the information on the operating experience should provide objective experience to support a conclusion that the program will adequately manage the effects of aging during the PEO.
The NRG staff reviewed the operating experience provided in the licensee's submittal and did not identify any operating experience that would indicate that the licensee should consider modifying its inspection program. Additionally, as part of its review of the "operating experience" program element, the staff performed an independent search of licensee event reports, event notifications, and inservice inspection summary reports for AN0-2 dating back to May of 2005.
From this independent review, the staff determined that the operating experience provided by the licensee was bounded by known industry operating experience (e.g., no previously unknown or recurring aging effects were identified by the licensee or NRG staff).
Based on its review of the AN0-2 Alloy 600 AMP, the NRC staff concludes that the licensee has appropriately evaluated plant-specific and industry operating experience. The staff confirmed that the "operating experience" program element satisfies the criteria in SRP-LR Section A.1.2.3.10 and, therefore, the staff concludes that it is acceptable.
4.0 CONCLUSION
The NRC staff reviewed Entergy's submittal dated July 18, 2016, to determine whether it contains sufficient information to demonstrate fulfillment of Entergy's license renewal commitment regarding the AN0-2 Alloy 600 AMP, and the acceptability of the proposed AMP.
Based on its review, the staff concludes that there is reasonable assurance that the licensee will adequately manage the aging effects of the nickel alloy components within the scope of the Alloy 600 AMP, consistent with the inservice inspection requirements specified in 1 O CFR 50.55a. Accordingly, the NRC staff approves the AN0-2 Alloy 600 AMP and concludes that the licensee's implementation of the program fulfills Commitment No. 1 for license renewal related to the AN0-2 Alloy 600 AMP.
Principal Contributor: R. Kalikian, NRR/DE Date: June 28, 2017
ML17167A083 OFFICE N RR/DORL/LPL4/PM NRR/DORL/LPL4/LA NAME TWengert PBlechman DATE 6/27/17 6/21/17 OFFICE N RR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME RPascarelli TWengert DATE 6/28/17 6/28/17