ML18310A013

From kanterella
Jump to navigation Jump to search

Relief from the Requirements of the ASME Code to Use Boiling Water Reactor Vessel Internals Guidelines as an Alternative
ML18310A013
Person / Time
Site: River Bend Entergy icon.png
Issue date: 11/16/2018
From: Robert Pascarelli
Plant Licensing Branch IV
To:
Entergy Operations
Regner, L M, 301-415-1906
References
EPID L-2018-LLR-0008
Download: ML18310A013 (12)
v • d • e


Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 16, 2018 Vice President, Operations Entergy Operations, Inc.

River Bend Station 5485 US Highway 61 St. Francisville, LA 70775

SUBJECT:

RIVER BEND STATION, UNIT 1 - RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE TO USE BOILING WATER REACTOR VESSEL INTERNALS GUIDELINES AS AN ALTERNATIVE (EPID L-2018-LLR-0008)

Dear Sir or Madam:

By application dated February 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18045A151 ), Entergy Operations, Inc. (Entergy or the licensee), submitted a relief request to the U.S. Nuclear Regulatory Commission (NRC) for the use of alternatives to certain inservice inspection (ISi) requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) Section XI requirements at River Bend Station, Unit 1 (RBS).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(1 ), the licensee requested to allow the use of the Electric Power Research Institute (EPRI) Boiling Water Reactor Vessel and Internals Project (BWRVIP) guidelines in lieu of specific ISi requirements since the proposed alternative would provide an acceptable level of quality and safety.

The NRC staff has reviewed the subject requests and concludes, as set forth in the enclosed safety evaluation, that Entergy's proposed alternative to implement the BWRVIP guidelines in lieu of the ASME Code, Section XI examination requirements for the subject components will provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1 ). Therefore, the NRC staff authorizes the alternative described in RBS-ISl-019 for RBS.

All other ASME Code, Section XI requirements for which relief was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.

If you have any questions, please contact Lisa Regner at 301-415-1906 or via e-mail at Lisa.Regner@nrc.gov.

Sincerely, Robert J. Pascarelli, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-458

Enclosure:

Safety Evaluation cc: Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ALTERNATIVE REGARDING PROPOSED USE OF BWRVIP GUIDELINES IN LIEU OF CERTAIN ASME CODE, SECTION XI REQUIREMENTS ENTERGY OPERATIONS, INC.

RIVER BEND STATION, UNIT 1 DOCKET NO. 50-458

1.0 INTRODUCTION

By application dated February 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18045A151 ), Entergy Operations, Inc. (Entergy or the licensee), requested an alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Section XI (also referred to as "the Code") to allow the use of the Electric Power Research Institute (EPRI) Boiling Water Reactor Vessel and Internals Project (BWRVIP) guidelines in lieu of specific inservice inspection (ISi}

requirements for components within the reactor pressure vessel (RPV) at River Bend Station, Unit 1 (RBS).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (1 O CFR) 50.55a(z)(1 ), the licensee requested to use the proposed alternative described in the licensee's February 13, 2018, submittal, RBS-ISl-019, on the basis that the proposed alternative would provide an acceptable level of quality and safety.

2.0 REGULATORY EVALUATION

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the ISi requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code, Section XI, 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 ISi interval and subsequent intervals comply with the latest Edition and Addenda of Section XI of the ASME Code that was incorporated by reference in 10 CFR 50.55a(a)(1)(ii), 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.

The regulation under 10 CFR 50.55a(z) states that the alternatives to the requirements of 10 CFR 50.55a(g) may be used when authorized by the U.S. Nuclear Regulatory Commission (NRC). A licensee's proposed alternative must be submitted to and authorized by the NRC prior Enclosure

to implementation. The licensee must demonstrate that the alternative meets one of the following options:

( 1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or (2) Hardship without a compensating increase in quality and safety. 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 regulatory requirements, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to propose and the Commission to authorize this alternative to the requirements of the ASME Code, Section XI.

3.0 TECHNICAL EVALUATION

3.1 Licensee's Proposed Alternative (RBS-ISl-019)

Applicable Code Edition and Addenda

The Code of Record for the RBS fourth 10-year ISi Interval is the 2007 Edition through the 2008 Addenda of the ASME Code, Section XI. The fourth 10-year ISi interval at RBS began on December 1, 2017, and is scheduled to end on November 30, 2027.

Components Affected by the Proposed Alternative The proposed alternative is applicable to the ASME Code Class 1 RPV interior, welded interior attachments, and core support structure (CSS) components, as identified in Examination Categories B-N-1 and B-N-2 of Table IWB-2500~1 of the ASME Code, Section XI:

  • Examination Category B-N-1, Item No. 813.10, RPV interior
  • Examination Category B-N-2, Item No. 813.20, interior attachments within the RPV beltline region
  • Examination Category B-N-2, Item No. 813.30, interior attachments welds beyond the RPV beltline region
  • Examination Category B-N-2, Item No. 813.40, surfaces of the welded CSS components These are also generally referred to in this safety evaluation (SE) as the RPV Internal (RVI) components or the "subject ASME Code components."

Applicable Code Requirements Visual examination requirements for Examinations Categories B-N-1 and B-N-2 components in Table IWB-2500-1 of the ASME Code, Section XI are as follows:

  • Examination Category B-N-1, Item No. B13.10-Examine accessible areas of the RPV interior each inspection period using the VT-3 visual examination method. 1
  • Examination Category B-N-2, Item No. B13.20 - Examine accessible interior attachment welds within the RPV beltline region each 10-year ISi interval using the VT-1 method.
  • Examination Category B-N-2, Item No. B13.30 - Examine accessible interior attachment welds beyond the RPV beltline region each 10-year ISi interval using the VT-3 method.
  • Examination Category B-N-2, Item No. B13.40 - Examine accessible surfaces of the CSS components each 10-year ISi interval using the VT-3 method.

Licensee's Proposed Alternative Pursuant to 10 CFR 50.55a(z)(1 ), the licensee submitted RBS-ISl-019 requesting NRC authorization to implement certain BWRVIP Inspection and Evaluation (l&E) guidelines in lieu of the subject ASME Code, Section XI examination requirements for the RPV interior, interior attachments, and CSS components.

The licensee stated that implementation of specific BWRVIP inspections in lieu of the ASME Code, Section XI ISi requirements for the subject components will comprehensively identify material condition issues with these components. The licensee noted that the BWRVIP guidelines focus on susceptible components, specify appropriate inspection methods capable of addressing anticipated degradation mechanisms, and specify reexamination at conservative intervals. In contrast, the ASME Section XI requirements were prepared before the BWRVIP initiative and have not evolved with the BWRVIP inspection operating experience. Attachment 3 of RBS-ISl-019 provides the BWRVIP inspection history for RBS.

The licensee provided a list of the BWRVIP l&E guidance documents that will be used in lieu of the ASME Code, Section XI examination requirements for the subject components. These BWRVIP documents are identified below.

  • BWRVIP-94, Revision 2, "BWR [Boiling Water Reactor] Vessel and Internals Project Program Implementation Guide," dated September 22, 2011 (ADAMS Accession No. ML11271A058, transmitted for information only);

1 Paragraph IWA-2210 of the ASME Code, Section XI defines three visual examination methods: VT-1, VT-2, and VT-3. VT-1 and VT-3 examinations are specified for Examination Categories B-N-1 and B-N-2.

VT-1 examinations are conducted to detect discontinuities and imperfections on the surface of components, including such conditions as cracks, wear, corrosion, or erosion. VT-3 examinations are conducted to determine the general mechanical and structural condition of components.

  • BWRVIP-25, "BWR Core Plate Inspection and Flaw Evaluation Guidelines" (NRC approval letter and proprietary SE dated December 19, 1999);
  • BWRVIP-26-A, "BWR Top Guide Inspection and Flaw Evaluation Guidelines" (NRC approval letter dated August 29, 2005, at ADAMS Accession No. ML052490550);
  • BWRVIP-38, "BWR Shroud Support Inspection and Flaw Evaluation Guidelines" (NRC approval letter and SE dated July 24, 2000, at ADAMS Accession No. ML003735498);
  • BWRVIP-47-A, "BWR Lower Plenum Inspection and Flaw Evaluation Guidelines" (NRC approval letter dated September 1, 2005, at ADAMS Accession No. ML052490537);
  • BWRVIP-48-A, "Vessel ID Attachment Weld Inspection and Flaw Evaluation Guidelines" (NRC approval letter dated July 25, 2005, at ADAMS Accession No. ML052130284);
  • BWRVIP-76, Revision 1-A, "BWR Core Shroud Inspection and Flaw Evaluation Guidelines" (Non-proprietary version of BWRVIP report dated May 2015 and NRC approval SE dated November 12, 2014, at ADAMS Accession No. ML15266A189); and
  • BWRVIP-100-A, "Updated Assessment of the Fracture Toughness of Irradiated Stainless Steel for BWR Core Shrouds" (NRC approval letter dated November 1, 2007, at ADAMS Accession No. ML073050135).

The ADAMS accession numbers provided above are for publicly available correspondence related to NRC approval of the applicable BWRVIP document. Although most of the BWRVIP documents are Electric Power Research Institute (EPRI) proprietary information, the licensee's

public submittal for RBS-ISl-019, dated February 13, 2018, shows how the specific BWRVIP inspection criteria from the above documents are to be used in lieu of the subject ASME Code, Section XI examination requirements.

Table 1 of Attachment 1 of RBS-ISl-019 provides a comparison of the ASME Code, Section XI examination requirements for Code Item Nos. B13.10, B13.20, B13.30, and B13.40 to inspection criteria in the applicable BWRVIP guidance document. This table addresses how the BWRVIP l&E criteria, including examination methods, examination coverage, examination frequency, and flaw evaluations, are to be implemented in lieu of the subject Code examination requirements under this proposed alternative. Attachment 2 of RBS-ISl-019 provides a more detailed description of BWRVIP inspection methods and how they compare to the applicable Code examination requirements.

The licensee stated that its proposed alternative will implement the BWRVIP-94 program implementation guidance. Where a revised version of a BWRVIP l&E guideline continues to meet the requirements of the version of the guideline that forms the safety basis for an NRG-authorized alternative pursuant to 10 CFR 50.55a(z), the guideline may be implemented.

Otherwise, the revised BWRVIP guideline will only be implemented after it has received NRC approval, or a plant-specific request for an alternative to implement it has been authorized in accordance with 10 CFR 50.55a(z). The licensee identified that Table 1 of Attachment 1 of RBS-ISl-019 represents the most current comparison between the ASME Code, Section XI examination requirements and the BWRVIP guidelines at the time of its application.

As part of its proposed alternative, the licensee also identified that if repair and/or replacement activities are required for the subject ASME Code components based on evaluation of relevant conditions under the BWRVIP guidelines, it will implement component repair and replacement activities in accordance with the requirements of the ASME Code, Section XI, Article IWA-4000.

Upon authorization by the NRC, the licensee's proposed alternative, as described in RBS-ISl-019, will be implemented for the duration of the fourth 10-year ISi interval, beginning on December 1, 2017, and ending on November 30, 2027.

Licensee's Basis for Use of the Proposed Alternative The licensee stated that BWRs now examine RVI components in accordance with the BWRVIP guidelines. These guidelines have been written to address l&E of safety-significant RVI components using appropriate examination methods and reexamination frequencies. The NRC has agreed with the BWRVIP approach in principle and has issued SEs for many of the BWRVIP guidelines. The licensee stated that implementation of the BWRVIP guidelines in lieu of the examination requirements of the ASME Code, Section XI, Examination Categories B-N-1 and B-N-2 will provide an acceptable level of quality and safety. of RBS-ISl-019 provides the BWRVIP inspection history for the RVI components at RBS, which shows inspections performed to date and flaws that have been detected in the components. The licensee stated that a plant-specific integrated leakage assessment was not required for RVI components that are part of emergency core cooling system (ECCS) flow paths because no known flaws related to leakage in the core spray piping, low-pressure coolant injection (LPCI) welds, or jet pump welds have been identified, and no through-wall flaws are identified in the core shroud.

As part of its basis to support implementation of the BWRVIP guidelines in lieu of the subject Code examination requirements, the licensee described plant-specific allowable leakage limits for the above RVI components to ensure that limits on peak fuel cladding temperature (PCT) are not exceeded during loss-of coolant accident (LOCA) events. Maximum allowable leakage for high-pressure core spray (HPCS), low-pressure core spray (LPCS), and LPCI are determined based on the difference between the Technical Specification 3.5.1 minimum ECCS flow rates and the reduced ECCS flow rates used in the LOCA analysis. The maximum allowable leakage through the jet pump welds and the core shroud should be no more than sum of the remaining leakage margin of the HPCS and LPCS systems. The licensee described how these limits on allowable leakage will ensure that the ECCS flow rates will not be reduced below those used in the LOCA analysis thereby ensuring that the PCTs determined by the RBS LOCA analysis will not be affected.

Based on NRC's approval of the BWRVIP guidelines and the comparisons performed in RBS-ISl-019 demonstrating how the guidelines are to be used in lieu of the subject ASME Code, Section XI examination requirements, the licensee determined that its alternative will avoid unnecessary inspections and will now be focused on the most recent BWR operating experience for the subject components. Therefore, the licensee concluded that its request when authorized will provide an acceptable level of quality and safety and will not adversely impact the health and safety of the public.

3.2 NRC Staff Evaluation Status and Implementation Scope for BWRVIP Guidelines Except for the BWRVIP-94 program implementation guidance, all of the BWRVIP reports that are identified in RBS-ISl-019 for implementation in lieu of the subject ASME Code, Section XI examination requirements have been generically reviewed and approved by the NRC. This includes those BWRVIP reports that do not have an "-A" affixed to the report, which represents NRC staff's review and approval. The scope of the NRC staff's review includes only those BWRVIP reports that are specially identified in RBS-ISl-019 as being part of this licensee's proposed alternative for the subject Code components; these reports are listed above in SE Section 3.1, "Licensee's Proposed Alternative (RBS-ISl-019)."

For those cases where future revisions to BWRVIP documents provide for a change in the scope of l&E from what is defined in the versions listed above, the NRC finds acceptable the licensee's statement in RBS-ISl-019 that it will implement the BWRVIP-94 program implementation guidance as part of this Code alternative. Specifically, where a revised BWRVIP document meets or exceeds the requirements of the earlier version of the BWRVIP document that formed the safety basis for the NRC-authorized alternative pursuant to 10 CFR 50.55a(z), the revised version of the document may be implemented upon issuance, as specified in BWRVIP-94. Otherwise, the revision to the BWRVIP document will only be implemented after it has been reviewed and approved by the NRC, or a plant-specific request for an alternative pursuant to 10 CFR 50.55a(z) has been authorized by the NRC to implement the revised version of the BWRVIP document. The NRC staff noted that Table 1 of of RBS-ISl-019 represents the licensee's most recent comparison between the ASME Code, Section XI, Examination Categories B-N-1 and B-N-2 requirements and the applicable BWRVIP guidelines at the time of the licensee's application.

The NRC staff reviewed the following information in the licensee's submittal for RBS-ISl-019 to determine whether its proposed alternative will provide an acceptable level of quality and safety at RBS:

  • The licensee's comparison of the specific BWRVIP inspection criteria to Examination Categories B-N-1 and B-N-2 requirements, as summarized in Table 1 of Attachment 1 of RBS-ISl-019 and discussed in Attachment 2 of the submittal;
  • The licensee's BWRVIP RVI inspection history for RBS provided in Attachment 3 of RBS-ISl-019; and
  • The BWRVIP flaw evaluation criteria and the licensee's discussion of leakage criteria for RVI components that are relied on for maintaining ECCS flow to ensure that limits on PCT are not exceeded during design basis LOCA events.

Comparison of ASME Examination Category B-N-1 Requirements with BWRVIP Guidelines For Examination Category B-N-1, RPV interior, the NRC staff verified that portions of the various examinations required by the applicable BWRVIP guidelines involve examination of accessible areas of the RPV interior during each refueling outage. Specifically, the examinations for core spray piping and spargers (BWRVIP-18, Revision 2-A), top guide (BWRVIP-26-A), jet pump welds and components (BWRVIP-41-A), interior attachments (BWRVIP-48-A), core shroud welds (BWRVIP-76, Revision 1-A), shroud support (BWRVIP-38),

and lower plenum components (BWRVIP-47-A) all provide access for assessing the condition of the RPV interior. Examining specific welds and components within the RPV interior above and below the core and the surrounding annulus area using remote cameras performs similar visual examinations of the RPV interior that are an acceptable alternative to VT-3 examinations required by Examination Category B-N-1. The NRC staff notes that evidence of wear, structural degradation, loose, missing, or displaced parts, foreign materials, and corrosion product buildup is readily observed during implementation of these BWRVIP inspection criteria. Therefore, the NRC staff determined that implementation of the specified BWRVIP guidelines as an alternative to the VT-3 examinations required by Examination Category B-N-1 would provide an acceptable level of quality and safety for visual inspection of the RPV interior.

Comparison of ASME Examination Category B-N-2 Requirements with BWRVIP Guidelines For Examination Category B-N-2, Item No. 813.20 RPV interior attachments within the beltline region, Item No. B13.30 RPV interior attachments outside of the beltline region, and Item No. 813.40 CSS components, the NRC staff compared the Code examination requirements with the corresponding inspection criteria specified in the applicable BWRVIP document cited in RBS-ISl-019. The staff noted that for Code Item No. 813.20 RPV interior attachments within the beltline region, the applicable BWRVIP examination methods are enhanced VT-1 (EVT-1) for the jet pump riser brace attachment welds and VT-1 for the lower surveillance specimen holder support bracket attachment welds whereas VT-1 examination is specified in the ASME Code, Section XI for both components based on accessibility. Relative to the Code VT-1 method, the EVT-1 method is specified for enhanced detection of tight cracks on the surface of components such as due to intergranular stress corrosion cracking, and includes additional requirements for surface cleaning. For the Code Item No. 813.30 RPV interior attachments outside of the beltline region (includes welded attachments for steam dryer support brackets,

guide rod support brackets, feedwater sparger support brackets, core spray piping support brackets, upper surveillance specimen holder support brackets, and shroud support attachments) and the 813.40 CSS components (includes the core shroud and the shroud support), the BWRVIP examination methods for the majority of the components are EVT-1 or ultrasonic testing {UT) as opposed to the VT-3 examination method specified in the ASME Code, Section XI. The UT and EVT-1 examination methods provide a superior level of sensitivity for detecting of aging effects compared to the Code-required VT-3 examination method.

Regarding the examination frequency and percent examination coverage, RBS-ISl-019 cites the inspection criteria in BWRVIP-48-A, which specify that the RPV beltline region jet pump riser brace attachments receive initial EVT-1 examinations of 100 percent of the attachments in the first 12 years and EVT-1 examination of 25 percent of the riser brace attachment population during each subsequent 6-year interval, compared to VT-1 of all accessible attachments every 10 years per Code Item No. 813.20. The slightly longer initial examination interval and lower percent coverage during subsequent 6-year intervals for the jet pump riser brace attachments is compensated for by the more sensitive EVT-1 examination method and the fact that BWRVIP-48-A defines the susceptible regions of the attachments that are to receive the EVT-1 examination. For all other 813.20, 813.30, and 813.40 RPV interior attachments and CSS components, the BWRVIP documents specify equivalent or shorter examination intervals and equivalent or more comprehensive coverage requirements than those specified in Examination Category B-N-2. Therefore, with respect to the examination methods, examination frequency, and percent coverage, the NRC staff determined that the BWRVIP inspection guidelines are at least as comprehensive as and usually exceed the corresponding ASME Code, Section XI, Examination Category B-N-2 requirements; thus, they will provide an acceptable level of quality and safety.

Operating Experience, Flaw Evaluation, and Plant-Specific Leakage Assessment To assess the impact of using the BWRVIP l&E guidelines as an alternative to the ASME Code, Section XI, Examination Categories B-N-1 and B-N-2 requirements, the NRC staff reviewed the BWRVIP inspection history for RBS that was reported in Attachment 3 of RBS-ISl-019. The staff confirmed that the licensee's RVI component inspection history provides objective evidence that the licensee's implementation of the BWRVIP guidelines results in more comprehensive examination coverage and better capability for detection of aging effects compared to the Code examination requirements. The staff noted that the relevant indications reported for the RBS RVI components are generally bounded by the industry operating experience for RVI component aging degradation in BWRs. For those cases where there are relevant indications, the staff confirmed that they are being appropriately evaluated and managed by the applicable BWRVIP document. The staff noted that inspection results reported for the Examination Category B-N-1, Item No. 813.10 RPV interior and the Examination Category B-N-2, Item Nos. 813.20 and 813.30 interior welded attachments identify no relevant indications. Relevant indications that are reported for the Item No. 813.40 CSS components are limited to several flaws in the core shroud welds. The flaws in the RBS core shroud are not through-wall flaws, and the BWRVIP-76-A core shroud guidelines specify very comprehensive l&E procedures and acceptance criteria for managing cracking in BWR core shrouds to provide reasonable assurance that the subject flaws do not compromise core shroud functionality during plant operations. It should be noted that BWR core shrouds have a relatively high degree of flaw tolerance, and the BWRVIP-76-A guidelines have proven highly effective in managing core shroud cracking based on many years of operating experience with this aging effect.

Comprehensive flaw evaluation procedures and acceptance criteria are specified in the applicable BWRVIP documents for all the Examination Category B-N-2 RPV interior attachment and CSS components at RBS. The NRC staff confirmed that the flaw evaluation methods and acceptance standards in the applicable BWRVIP documents for the RPV interior attachments and CSS components are at least equivalent to, and often more specific and more comprehensive than the flaw evaluation methods and acceptance standards of ASME Code paragraph IWB-3142 and Subsubarticle IWB-3520 for inservice VT-1 and VT-3 examinations of these components. The staff therefore, determined that the BWRVIP flaw evaluation methods and acceptance standards will provide an acceptable level of quality and safety by ensuring that the appropriate corrective actions are taken based on the evaluation of relevant indications.

Flaw evaluations are not specified for RPV interior areas under Examination Category B-N-1 because these exams are only performed to detect evidence of wear, structural degradation, loose, missing, or displaced parts, foreign materials, and corrosion product buildup in the RPV interior.

Several RVI components - core spray piping, jet pump assemblies, LPCI coupling, and core shroud - are relied on to maintain ECCS flow to ensure that limits on PCT are not exceeded during design basis LOCA events. Therefore, an important aspect of an effective flaw evaluation for these components is an integrated leakage assessment, as per the applicable BWRVIP l&E guidelines. Since no flaws have been detected in the fluid-retaining components of the core spray piping, jet pumps, and LPCI couplings, and there are no through-wall cracks in the core shroud, a plant-specific integrated leakage assessment related to ECCS flow during LOCA events is not required at this time. The NRC staff confirmed that the licensee established conservative limits on the maximum allowable ECCS leakage for use in future flaw evaluations under these BWRVIP guidelines if through-wall flaws are detected in these components.

Based on the above evaluation, the NRC staff finds that the licensee's proposed alternative, as described in RBS-ISl-019, to implement the BWRVIP l&E guidelines in lieu of the ASME Code, Section XI examination requirements for the Examination Categories B-N-1 and B-N-2 components will provide and acceptable level of quality and safety at RBS.

4.0 CONCLUSION

As set forth above, the NRC staff has determined that the licensee's proposed alternative to implement the BWRVIP guidelines in lieu of the ASME Code, Section XI examination requirements for the subject components will provide an acceptable level of quality and safety.

Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)( 1). Therefore, the NRC staff authorizes the alternative described in RBS-ISl-019 for RBS.

All other ASME Code, Section XI requirements for which this alternative was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.

Principal Contributor: Christopher R. Sydnor, NRR Date of Issuance: November 16, 2018

SUBJECT:

RIVER BEND STATION, UNIT 1 - RELIEF FROM THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE TO USE BOILING WATER REACTOR VESSEL INTERNALS GUIDELINES AS AN ALTERNATIVE (EPID L-2018-LLR-0008)

DATED NOVEMBER 16, 2018 DISTRIBUTION:

PUBLIC PM File Copy RidsACRS_MailCTR Resource RidsNrrDorlLpl4 Resource RidsNrrPMRiverBend Resource RidsNrrLAPBlechman Resource RidsNrrLAJBurkhardt Resource RidsRgn4MailCenter Resource ADAMS Access1on No: ML18310A013 *b,yema1*1 OFFICE NRR/DORL/LPL4/PM NRR/DORL/LAiT NRR/DORL/LPL4/LA NAME LRegner PTalukdar* PBlechman (JBurkhardt for)

DATE 11/7/18 11/7/18 11/13/18 OFFICE NRR/DMRL/MVIB/BC N RR/DORL/LPL4/BC NAME DAIiey* RPascarelli DATE 10/31/18 11/16/18 OFFICIAL AGENCY RECORD

Retrieved from "https://kanterella.com/w/index.php?title=ML18310A013&oldid=2070261"