ML13092A401
| ML13092A401 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 04/18/2013 |
| From: | Meena Khanna Plant Licensing Branch 1 |
| To: | Pacilio M Exelon Nuclear |
| Lamb J | |
| References | |
| TAC ME9492 | |
| Download: ML13092A401 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 18, 2013 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, I L 60555
SUBJECT:
OYSTER CREEK NUCLEAR GENERATING STATION - RELIEF FROM THE REQUIREMENTS OF THE ASME CODE, RELIEF REQUEST NO. 15R-01 FOR EXPANDED APPLICABILITY FOR USE OF ASME CODE CASE N-661-1 (T AC NO. ME9492)
Dear Mr. Pacilio:
By letter dated August 28,2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12243A287), as supplemented by letter dated December 3,2012 (ADAMS Accession No. ML12339A012), Exelon Generation Company (the licensee) submitted request for alternative (RFA) 15R-05 for the U.S. Nuclear Regulatory Commission's (NRC) approval. The licensee proposed an alternative to certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI. RFA 15R 05 relates to the applicability of ASME Code Case N-661-1, "Alternative Requirements for Wall Thickness Restoration of Class 2 and 3 Carbon Steel Piping for Raw Water Service," which is limited up to the 2005 Addenda of the ASME Code. RFA 15R-05 is requested for the fifth 10 year inservice inspection (lSI) interval of the Oyster Creek Nuclear Generating Station (Oyster Creek) which commenced on January 15, 2013. The 2007 Edition through the 2008 Addenda of the ASME Code,Section XI, is the current Code of record at Oyster Creek. Specifically, pursuant to Title 10 of the Code Federal Regulations (10 CFR) Section 50.55a(a)(3)(i), the licensee requested to use the proposed alternative on the basis that the alternative provides an acceptable level of quality and safety.
The NRC staff has reviewed the subject request and has concluded, as set forth in the enclosed safety evaluation, that the proposed alternative described in RFA 15R-01 provides an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all ofthe regulatory requirements set forth in 10 CFR 50.55a(a)(3)(O, and is in compliance with the ASME Code's requirements.
Therefore, the NRC staff authorizes the alternative described in Relief Request 15R-01 for the fifth 1ST interval at Oyster Creek, which began on January 15, 2013, and ends on January 14, 2023. All other ASME Code requirements for which relief was not specifically requested and approved in the subject request remain applicable, including a third party review by the Authorized Nuclear Inservice Inspector.
M. Pacilio
- 2 If you have any questions regarding this matter, please contact the Senior Project Manager, John G. Lamb, at (301) 415-3100 or bye-mail at John.Lamb@nrc.gov.
Sincerely, Meena Khanna, Chief Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-219
Enclosure:
Safety Evaluation cc w/enclosure: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR RELIEF ISR-01 FIFTH INSERVICE INSPECTION INTERVAL OYSTER CREEK NUCLEAR GENERATING STATION EXELON NUCLEAR DOCKET NO. SO-219
1.0 INTRODUCTION
By letter dated August 28, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12243A287), as supplemented by letter dated December 3,2012 (ADAMS Accession No. ML12339A012), Exelon Generation Company (the licensee) submitted request for alternative (RFA) ISR-OS for the U.S. Nuclear Regulatory Commission's (NRC) approval. The licensee proposed an alternative to certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI. RFA ISR OS relates to the applicability of ASME Code Case N-661-1, "Alternative Requirements for Wall Thickness Restoration of Class 2 and 3 Carbon Steel Piping for Raw Water Service," which is limited up to the 200S Addenda of the ASME Code. RFA ISR-OS is requested for the fifth 10 year inservice inspection (lSI) interval of the Oyster Creek Nuclear Generating Station (Oyster Creek) which commenced on January 1S, 2013. The 2007 Edition through the 2008 Addenda of the ASME Code,Section XI, is the current code of record at Oyster Creek.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) SO.SSa(a)(3)(i),
the licensee proposed an alternative to repair or replacement (i.e., the applicability of ASME Code Case N-661-1 is extended to the 2007 Edition through 2008 Addenda for use in the Oyster Creek fifth 10-year lSI interval) for Class 2 and 3 carbon steel raw water piping systems, on the basis that the alternative provides an acceptable level of quality and safety.
2.0 REGULATORY EVALUATION
10 CFR SO.SSa(g)(4) specifies that ASME Code Class 1, 2, and 3 components (including supports) must meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the Enclosure
- 2 requirements in the latest edition and addenda of Section XI of the ASME Code, incorporated by reference in 10 CFR 50.55a(b), 12 months prior to the start of the 120-month interval, subject to the conditions listed therein.
10 CFR 50.55a(a)(3) states, in part, that alternatives to the requirements of paragraph (g) of 10 CFR 50.55a may be used, when authorized by the NRC, if the licensee demonstrates (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the NRC to authorize the alternative requested by the licensee.
3.0 TECHNICAL EVALUATION
3.1 ASME Code Components Affected (As stated)
ASME Code Class:
Class 2 and 3 Component:
Carbon Steel Piping System:
Raw Water Piping System 3.2 Applicable Code Edition and Addenda (As stated)
The Oyster Creek code of record for the fifth 10-year lSI interval is the 2007 Edition through 2008 Addenda of the ASME Code,Section XI.
3.3 Applicable Code Requirement (As stated)
IWA-2441 (b) of the ASME Code,Section XI, requires that code cases be applicable to the edition and addenda specified in the Inspection Plan.
ASME Code Case N-661-1, "Alternative Requirements for Wall Thickness Restoration of Class 2 and 3 Carbon Steel Piping for Raw Water Service,"
provides requirements that may be used to restore wall thickness for raw water piping systems that have experienced internal wall thinning. The NRC has accepted ASME Code Case N-661-1 with conditions in Regulatory Guide (RG) 1.147, Rev. 16, [Ulnservice Inspection Code Case Acceptability, ASME Section XI, Division 1"].
3.4 Reason for Relief (As stated)
On January 15, 2013, Oyster Creek started its fifth 10-year lSI interval under the requirements of the 2007 Edition through the 2008 Addenda of the ASME Code,Section XI. When implementing this edition and addenda, IWA-2441 (b) requires that code cases be applicable to the edition and addenda specified in the Inspection Plan. ASME Code Case N-661-1 has an applicability limited up to the
- 3 2004 Edition through 2005 Addenda which is identified in the latest Applicability Index for Section XI Cases.
Since ASME Code Case N-661-1 only applies up to the 2004 Edition through 2005 Addenda, paragraph IWA-2441 (b) does not allow the use of this code case for the Oyster Creek fifth 1 O-year lSI interval program.
3.5 Proposed Alternative and Basis for Use (As stated)
The licensee proposed the applicability of ASME Code Case N-661-1 be extended to the 2007 Edition through 2008 Addenda for use in the Oyster Creek fifth 1 O-year lSI interval program.
ASME Code Case N-661-1 is an acceptable alternative for restoring wall thickness for raw water piping systems that have experienced internal wall thinning. The NRC has accepted ASME Code Case N-661-1 with conditions in RG 1.147, Rev. 16. This request does not propose any technical changes to ASME Code Case N-661-1. This request is submitted to correct a timing situation which has resulted from the application of the 2007 Edition through the 2008 Addenda of the ASME Code,Section XI, at Oyster Creek.
3.6 Duration of Relief (As stated)
RFA 15R-05 is requested for the fifth 10-year lSI interval of Oyster Creek, which commenced on January 15, 2013.
3.7
NRC Staff Evaluation
The NRC staff has evaluated RFA 15R-05 pursuant to 10 CFR 50.55a(a)(3)(i). The NRC staff evaluation focuses on whether the proposed alternative provides an acceptable level of quality and safety.
ASME Code Case N-661-1 provides alternative requirements for wall thickness restoration of the Class 2 and 3 piping of the raw water service systems that have experienced internal wall thinning. The ASME Code,Section XI, IWA-2441 (b), requires that code cases shall be applicable to the edition and addenda specified in the Inspection Plan. In accordance with the latest Applicability Index for Section XI Cases, the use of ASME Code Case N-661-1 is limited up to the 2005 Addenda. The licensee has adopted the 2007 Edition through 2008 Addenda as the code of Record for the fifth 10-year lSI interval at Oyster Creek. As an alternative to the ASME Code for repair or replacement of Class 2 and 3 carbon steel raw water piping systems, the licensee proposed to use ASME Code Case N-661-1 during the Oyster Creek fifth 10-year lSI interval.
The NRC staff has accepted ASME Code Case N-661-1, with conditions, in RG 1.147, Rev. 16.
These conditions are: (1) If the cause of the degradation has not been determined, the repair is only acceptable until the next refueling outage; (2) When through-wall repairs are made by welding on surfaces that are wet or exposed to the water, the weld overlay repair is only acceptable until the next refueling outage. By letter dated December 3, 2012, in response to the
~4-NRC staff's request for additional information (RAI), the licensee stated that all conditions mandated by the NRC in RG 1.147, Rev. 16, for the use of ASME Code Case N-661-1 will be complied with. The NRC staff has determined that the licensee did not propose any changes to the requirements of ASME Code Case N-661-1 and all related requirements in the 2007 Edition through 2008 Addenda, except requesting to use this code case with the current Oyster Creek Code of record. Therefore, the NRC staff finds that ASME Code Case N-661-1, with all related requirements in the 2007 Edition through 2008 Addenda, provides an acceptable level of quality and safety if all conditions specified by the NRC in RG 1.147, Rev. 16, for use of this code case are met.
In addition, the NRC staff notes that the ASME Code committees approved the latest version of Code Case N-661 (Le., N-661-2). However, the NRC has not yet accepted ASME Code Case N-661-2 in RG 1.147 by rule making (10 CFR SO.SSa). The NRC staff expects that, once ASME Code Case N-661-2 is accepted in RG 1.147 by the NRC rulemaking to supersede Code Case N-661-1, Oyster Creek will update its fifth 10-year lSI program to use Code Case N-661-2.
Therefore, the NRC's approval to use ASME Code Case N-661-1 is limited to the end of the fifth 10-year lSI interval or until the NRC approves ASME Code Case N-661-2, whichever occurs earlier. As soon as the NRC approves ASME Code Case N-661-2, Relief Request ISR-OS becomes obsolete and the licensee can no longer use ASME Code Case N-661-1.
4.0 CONCLUSION
As set forth above, the NRC staff has determined that the proposed alternative provides an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR SO.SSa(a)(3)(i).
Therefore, the NRC staff authorizes the use of RFA ISR-OS at Oyster Creek for the fifth 10-year lSI interval until the NRC accepts ASME Code Case N-661-2 in RG 1.147 by rulemaking.
As soon as the NRC officially approves ASME Code Case N-661-2, or when the fifth lSI interval ends, whichever occurs earlier, Relief Request ISR-OS becomes obsolete and the licensee can no longer use ASME Code Case N-661-1 All other ASME Code,Section XI, requirements for which relief was not specifically requested and authorized herein by the NRC staff remain applicable, including the third party review by the Authorized Nuclear Inservice Inspector.
Principle Contributor: Ali Rezai Date: April 18, 2013
- via email OFFICE LPL1-2/PM LPL1-2/LA
- EPNB/BC LPL1-21BC NAME JLamb ABaxter*
TLupold*
MKhanna DATE 04/02/13 04/10/13 03/27/13 4/18/13