ML20211P781

SER Approving Second 10-year Interval Inservice Insp Program Plan Relief Request RR-ENG-2-8 (to Use Code Case N-491-2) for South Texas Project,Units 1 & 2

ML20211P781
Person / Time
Site:	South Texas
Issue date:	09/09/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20211P774	List: ML20211P767 ML20211P781
References
NUDOCS 9909140106
Download: ML20211P781 (3)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SECOND 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN RELIEF REQUEST RR-ENG-2-8 (TO USE CODE CASE N-491-2)

STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT. UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499

1.0 INTRODUCTION

The inservice inspection (ISI) of the American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda as required by 10 CFR 50.55a(g),

except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). The regulation at 10 CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (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.

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1,2, and 3 components (including supports) shall 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 second 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the South Texas Project, Units 1 and 2, during the second 10-year ISI interval is the 1989 Edition. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Commission approval.

Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose 9909140106 990909 PDR P ADOCK 05000498 PDR

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alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed. )

t in a [[letter::NOC-AE-000501, Requests Relief from ASME Section XI Code NDE Requirement to Perform VT-1 Visual Exam on Accessible Surfaces of Reactor Pressure Vessel Flange Inserts (Bushings).Encl Relief Request Applicable to Second ISI Interval for Units 1 & 2|letter dated May 17,1999]], the South Texas Project requested approval for the implementation of the ASME Section XI Code Case N-491-2 dated March 12,1997, " Alternative Rules for Examination of Class 1,2, and 3, and MC Component Supports of Light-Water Cooled Power Plants,"in lieu of the requirements of Subsection IWF of the Section XI Code l applicable to determining the component supports subject to examination and establishing examination requirement for component support.

1 The staff has reviewed and evaluated the licensee's request and the supporting information pertaining to use of Code Case N-491-2 as an alternative to the Code requirements for both units of the South Texas Project.

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2.0 DISCUSSION Request for Aethorization to implement Alternativos to Code Requirements Contained in Code

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Case N-491-2," Alternative Rules for Examination of Class 1,2, and 3, and MC Component Supports of Light Water Cooled Power Plants "

System / Component Affected by Use of Code Case Supports for ASME Code Classes 1,2, and 3 components and piping I

Code Reauirements from Which Relief is Reauested i

IWF-1000, " Scope and Responsibility" i IWF-2000, " Examination and Inspection" l IWF-3000, " Standards for Examination Evaluation" '

Licensee's Basis for Relief from Code Reauirement in accordance with the provisions of 10 CFR 50.55a(a)(3)(i), the South Texas Project requests approval to use the requirements of Section XI Code Case N-491-2 as an alternative to IWF-1000,2000, and 3000. The South Texas Project believes that the requirements of Code Case N-4912 will provide an acceptable level of quality and safety while reducing the costs and radiation exposure associated with the inservice examinations of Class 1,2, and 3 component supports.

Licensee's Proposed Alternative to Code Reauirements Code Case N-4912 is proposed as an alternative to Subsection IWF of the ASME Code,Section XI for Class 1,2, and 3 and MC component supports. The implementation of Code Case N-491-2 will allow a reduced sampling rate in comparison to that of the applicable Code for Class 1,2, and 3 piping supports.

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l 3.0 EVALUATION I The licensee has requested approval for implementation of the alternative rules of the ASME I Section XI Code Case N-491-2 dated March 12,1997, " Alternative Rules for Examination of Class 1,2, and 3, and MC Component Supports of Light-Water Cooled Power Plants," in lieu of the requirements of subsection IWF-1000,2000, and 3000 of the 1989 Edition, ASME Code,Section XI. The staff notes that the alternative examination requirements are related to those stated in Section XI, Division 1, Subsection IWF when determining the component supports j subject to examination and establishing requirements, and they were previously identified in '

Code Cases N-491 and N-491 1. These two code cases, with identical examination requirements and having minor editorial changes in N-491-1, were incorporated into Regulatory Guide 1.147, " Inservice inspection Code Case Acceptability," Revisions 11 and 12, respectively. i Subsequently, Code Case N 491-1 was superseded by Code Case N-491-2. The staff, therefore, has focused its review to evaluate the changes in Code Case N-491-2 with respect to the NRC-approved Code Case N-491-1. -

The staff finds that the changes are only applicable to the paragraphs under " Acceptance by Evaluation or Test"in regard to preservice and inservice examinations, which merely clarifies that a support containing a relevant condition could be put into service if it were found acceptable by an evaluation or test. These paragraphs further waive any subsequent l preservice examination of a support containing a relevant condition that was found acceptable by an evaluation or test and restored to its original design condition. The staff has determined that the changes in Code Case N-491-2 with respect to the requirements of Code Case N-491-1 have no impact on the integrity and, hence, the intended function of the support and, therefore, Code Case N-491-2 would provide an equivalent protection as that of Code Case ]

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4.0 CONCLUSION

The staff has evaluated the information provided by the licensee in support of its request for relief to implement Code Case N-491-2 as an alternative to the requirements of subsections I IWF-1000,2000, and 3000 of the 1989 Edition of the ASME Code,Section XI. The staff )

concludes that the changes in Code Case N-491-2 with respect to corresponding sections of {

the NRC-approved Code Case N-491-1 would provide an acceptable level of quality and safety, l Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the alternative proposed in relief request RR-ENG-2 8 to use Code Case N-491-2 is authorized for the second 10-year inspection interval of the South Texas Project, Units 1 and 2.

Principal Contributor: P. Patnaik Date: September 9, 1999

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