ML19240B112

Proposed Alternative to the Requirements of the American Society of Mechanical Engineers Code

ML19240B112
Person / Time
Site:	Braidwood
Issue date:	09/09/2019
From:	Lisa Regner Plant Licensing Branch III
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Wiebe J
References
EPID L-2019-LLR-0007
Download: ML19240B112 (7)

Text

UNITED STATES WASHINGTON, D.C. 20555-0001 September 9, 2019 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)

Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

BRAIDWOOD STATION, UNITS 1 AND 2 - PROPOSED ALTERNATIVE TO THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE (EPID L-2019-LLR-0007)

Dear Mr. Hanson:

By letter dated January 31, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19031C900), Exelon Generation Company, LLC (Exelon, the licensee) requested to use an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with snubber examination at Braidwood Station, Units 1 and 2.

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a(z)(1 ), the licensee requested to use the proposed alternative on the basis that it provides an acceptable level of quality and safety.

The U.S. Nuclear Regulatory Commission (NRC or Commission) staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that Exelon has adequately addressed all regulatory requirements in 10 CFR 50.55a(z)(1). Therefore, the NRC staff authorizes the use of the alternative request 14-RS-1 for Braidwood Station, Unit 1, for the fourth 10-year inservice inspection (ISi) interval snubber program which started on August 29, 2018, and is scheduled to end on July 28, 2028, and for Braidwood Station, Unit 2, for the fourth 10-year ISi interval snubber program, which started on November 5, 2019, and is scheduled to end on October 16, 2028.

All other ASME OM Code requirements for which relief was not specifically requested and approved remain applicable.

B. Hanson If you have any questions, please contact the Project Manager, Joel Wiebe at 301-415-6606 or via e-mail at ~:::;.:;.:..:c-'-====.;;,.=.::.a*

isa M. Regner, Acting Branch Chief Plant Licensing Branch 111 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-456 and 50-457

Enclosure:

Safety Evaluation cc: Listserv

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST TO USE ALTERNATIVE 14-RS-1 REGARDING SNUBBER EXAMINATIONS EXELON GENERATION COMPANY, LLC BRAIDWOOD STATION, UNITS 1 AND 2 DOCKET NOS. 50-456 AND 50-457

1.0 INTRODUCTION

By letter dated January 31, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19031C900), Exelon Generation Company, LLC (Exelon, the licensee) submitted an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code),

associated with snubber examination at Braidwood Station (Braidwood), Units 1 and 2.

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(1 ), the licensee requested to use proposed alternative 14-RS-1 on the basis that the alternative provides an acceptable level of quality and safety.

The Braidwood, Unit 1, fourth 10-year inservice inspection (ISi) and snubber inservice examination and testing interval started on August 29, 2018, and is scheduled to end on July 28, 2028. The Braidwood, Unit 2, fourth 10-year ISi and snubber inservice examination and testing interval started on November 5, 2018, and is scheduled to end on October 16, 2028.

2.0 REGULATORY EVALUATION

As required by 10 CFR 50.55a(g), "lnservice Inspection Standards Requirements for Operating Plants," ISi of certain ASME Code Class 1, 2, and 3 components must be performed in accordance with that specified in Section XI of ASME Boiler Pressure Vessel (BPV) Code (or ASME OM Code for snubber examination and testing) and applicable addenda incorporated by reference in the regulations.

As required by 10 CFR 50.55a(b)(v)(B), "OM Condition: Snubbers, Second Provision," the licensee must comply with the provisions for examination and testing snubbers in Subsection ISTD of the ASME OM Code and make appropriate changes to their technical specifications or licensee-controlled documents when using 2006 Addenda and later editions and addenda of the Section XI of the ASME BPV Code."

Enclosure

As required by 10 CFR 50.55a(z), alternatives to the requirements of paragraph (g) of 10 CFR 50.55a may be used, when authorized by the Nuclear Regulatory Commission (NRC), if the licensee demonstrates: (1) the proposed alternatives provide an acceptable level of quality and safety or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

3.0 TECHNICAL EVALUATION

3.1 Licensee's Proposed Alternative 14-RS-1 The licensee requested to extend snubber examination and testing frequency requirements of the ASME OM Code for all snubbers within the scope of the Braidwood, Units 1 and 2, snubber programs as permitted by ASME OM Code Case OMN-13, Revision 2 ..

Applicable Code Edition/Addenda The applicable ASME BPV Code edition and addenda for Braidwood, Units 1 and 2, fourth 10-year ISi interval is the 2013 Edition with no Addenda. Therefore, per 10 CFR 50.55a(b)(3)(v)(B), the applicable requirement for snubber inservice examination and testing is the 2012 Edition of the ASME OM Code with no Addenda.

Applicable Code Requirements ISTD-4252, "Subsequent Examination Intervals," (c}, states "The duration of examination intervals following the completion of the second refueling outage shall be in accordance with Table ISTD-4252-1."

ISTA-3130, "Application of Code Cases," (b}, states, "Code Cases shall be applicable to the edition and addenda specified in the test plan."

ASME OM Code Case OMN-13, Revision 2, "Performance-Based Requirements for Extending Snubber lnservice Visual Examination Interval at LWR Power Plants."

Reason for Request

The licensee states:

ISTA-3130(b) states, "Code Cases shall be applicable to the edition and addenda specified in the test plan." ASME has approved Code Case OMN-13, Revision 2, "Performance-Based Requirements for Extending Snubber lnservice Visual Examination Interval at LWR Power Plants," in ASME OM Code 2012 Edition.

This Code Case OMN-13, Revision 2 is unconditionally approved for use in Regulatory Guide (RG) 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code," Revision 2. The Braidwood Units 1 and 2, code of record for the fourth ISi interval for snubbers examination and testing is the ASME OM Code 2012 Edition. However, Code Case OMN-13, Revision 2, states in the Applicability section that it is applicable to ASME OM Code 1995 Edition through 2011 Addenda. Braidwood will be implementing the ASME OM Code 2012 Edition for its Snubber Programs and proposes to also implement Code Case OMN-13, Revision 2, for extending the examination interval for snubbers.

Proposed Alternative The licensee proposes to use ASME OM Code Case OMN-13, Revision 2, with the 2012 Edition of the ASME OM Code in lieu of the 1995 Edition through 2011 Addenda of the ASME OM Code, as stated in the applicability section of Code Case OMN-13, Revision 2. The proposed alternative will be utilized for the Braidwood, Units 1 and 2, fourth ISi 10-year interval for snubber inservice examination and testing.

3.2 NRC Staff Evaluation The 2012 Edition of the ASME OM Code, Section ISTD-4252(c), requires snubber examination intervals following the second refueling outage to be in accordance with intervals specified in Table ISTD-4252-1. The snubber visual examination interval can be extended up to 48 months by meeting the requirements as specified in the Table ISTD-4252-1 and its notes. The ASME OM Code Case OMN-13, Revision 2, allows an extension of the visual examination interval beyond the interval allowed in Table ISTD-4252-1. ISTA-3130(b), requires Code Cases shall be applicable to the edition and addenda specified in the test plan. The licensee has proposed to use ASME OM Code Case OMN-13, Revision 2, to extend the visual examination interval beyond the interval allowed by Table ISTD-4252-1 for all snubbers in the snubber/ISi programs.

Specifically, the licensee proposes to apply ASME OM Code Case OMN-13, Revision 2, to the 2012 Edition of the ASME OM Code in lieu of the 1995 Edition through 2011 Edition, to extend the visual inspection frequency of snubbers in the ISi program.

Application of ASME OM Code Cases is addressed in 10 CFR 50.55a(b)(6) through references to RG 1.192, Revision 2, "Operation and Maintenance Code Case Acceptability, ASME OM Code, which lists acceptable and conditionally acceptable Code Cases for implementation in the ISi interval for Snubber program. RG 1.192, Revision 2, shows Code Case OMN-13, Revision 2, in Table 1 as acceptable for use without conditions. Code Case OMN-13, Revision 2, was published with the 2012 Edition of the ASME OM Code, and it is applicable to the 1995 Edition through the 2011 Addenda of the ASME OM Code. There is no technical reason for prohibiting the use of the Code Case OMN-13, Revision 2 with the 2012 Edition of the ASME OM Code.

Further NRC staff review of the 2012 Edition of the ASME OM Code and Code Case OMN-13, Revision 2, confirmed that there are no changes in the applicable Code sections referenced within the Code Case OMN-13, Revision 2. Therefore, the NRC staff concludes that the licensee's proposed alternative provides an acceptable level of quality and safety.

4.0 CONCLUSION

As set forth above, the NRC staff determined that for alternative request 14-RS-1 for Braidwood, Units 1 and 2, the proposed alternative provides an acceptable level of quality and safety for the snubbers. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)( 1) for request 14-RS-1. Therefore, the NRC staff authorizes the use of the alternative request 14-RS-1 for Braidwood, Unit 1, for the fourth 10-year ISi interval snubber program which started on August 29, 2018, and scheduled to end on July 28, 2028, and for Braidwood, Unit 2, for the fourth 10-year ISi interval snubber program, which started on November 5, 2019, and are scheduled to end on October 16, 2028.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable.

Principal Contributor: Gurjendra S. Bedi, NRR Date of issuance: September 9, 2019

ML192408112 *via email OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DMLR/MPHB/BC NAME JWiebe SRohrer SBailey*

DATE 09/04/19 08/29/19 08/07/19 OFFICE NRR/DORL/LPL3/BC (A) NRR/DORL/LPL3/PM NAME LRegner JWiebe DATE 09/05/19 09/09/19