ML20216C111

Safety Evaluation Granting Three of Seven Requests Submitted by Util 861020 Ltr for Relief from Inservice Insp & Testing Requirements.Four Requests Withdrawn,Per 870122,0410 & 0507 Ltrs

ML20216C111
Person / Time
Site:	Yankee Rowe
Issue date:	06/18/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20216C085	List: ML20216C081 ML20216C111
References
NUDOCS 8706300218
Download: ML20216C111 (4)

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• UNI'TED STATES NUCLEAR REGULATORY COMMISSION l

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SAFETY EVALUATION BY-OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RE0 VEST FOR' RELIEF FROM INSERVICE l INSPECTION AND TESTING REQUIREMENTS' j c

, YANKEE ATOMIC ELECTRIC COMPANY 5 YANKEE NUCLEAR POWER. STATION L4 DOCKET N0. 50-029-l INTRODUCTION' .1 4

By letter dated October 20, 1986, the licensee, Yankee Atomic Electric, Company l (YAEC)submittedsevenreliefrequestsdealingwithinserviceinspection,(ISI)'.

and inservice testing (IST) requirements. 4

-j In letters' dated January 22,1987, April 10,1987'and May 7,1987, YAEC . .

' withdrew.four~of the requests, which are not addressed further'in this safety' i evaluation. The remaining relief requests are evaluated below.

EVALUATION OF RELIEF RE00ESTS j

1. Relief- Request No. '1, Charging.and Volume Control System, Class 2, Code Category G-H ClassL 2 portions of the charging system -(from CH-M0V'-522/523 to -

CH-V-611/CH-V-617)areinvolved.

Code Examination Requirement (1977 Edition through Summer 1978 Addenda)

IWC-5222(a): . The system hydrostatic test' pressure shall.be:at.least 1.10 times the' system pressure P with de least1.25 times'thesystemfressure'signtemperature'of200*F.orless,andat s

P for systems'with' design' temperature sy above 200'F.-

j Code Relief Request i

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Relief is requested from pressure test requirements of-IWC-5222(a) for portions of'the charging system, i

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Licensee ~BasisDfor Relief The subject' portions of .the charging ~ system cannot be.hydrostatically.testedi

. ati the Class .2 required pressure. This would result in overpressurization of

- the unisolatable Class 1 piping. .,

- Licensee Proposed Alternative Test' This section of piping will.be subjected to a hydrostatic test at the Class 11 required pressure which provides assurance of pressure boundary integrity.

' Staff Evaluation'~

The subject portions of Class 2 piping cannot be isolated from the Class 1 ,

piping. LThe. hydrostatic test pressure for Class'1 piping is 1.10 times the i system nominal' operating pressure. P and is'1,ess than the Class ? test

pressure. As indicated by the lice 8see, the'. Class 2 test-pressure may result-

• in-overpressuring the unisolatable Class 1 portions of piping. ' The ,

alternative testing' proposed by.the licensee is to.perfonn the hydrostatic test;of the' subject Class _2. piping'together with:the'u'nisolatable Class 1 piping at the Class I required pressure. The alternative testing is i adequate'to provide assurance of the-structural integrity of the.; system. .

Relief from the' Class 2 pressure test requirements for the portions'of- the ,

charging system that cannot be isolated fromLClass 1 piping may be granted ast 6 requested.

2. Relief Request No. 6,- Shutdown Cooling System Piping, Cla'ss 12,' Code Category C-F Thirty-nine (39) pipe welds are involved.

3. Relief Request No. 7, Safety Injection Piping,iClass 2, Code' Category '

C-F .;

Thirty-three (33) pipe welds are involved. , .j Code Examination Requirement (1974 Edition through Summer 1975 Addenda) j IWC-2411(b): The examinations required by IWC-2520. shall . be -perfonned such that 100% of the required examinations of.the. components'will be completed over 1 the system's service lifetime, a IWC-2411(e): The required examinations assigned.to the components in.each.  ;

stream of the system shall be completed by the:end of the service lifetime, i butdivided'amongthenumber.ofinspection' intervals-(e.g.,four' intervals.for.

40-year designjservice lifetime.) .

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Code Relief Request l

Relief is requested from the requirement that 100% of the required l examinations be completed over the service lifetime of the plant. The i licensee proposes to prorate the number of welds required to be examined l during the first interval. j i

Licensee Basis for Relief j When the licensee completed its first inspection interval in 1974, examination (

of Safety Class 2 pipe welds were not required by Section XI. The intent of  ;

Section XI is to examine a percentage of welds over time to identify any )

system degradation. . The licensee does not believe any benefit is obtained by j backfitting the number of welds required to be inspected for the first {

interval. In addition, these examinations would result in unnecessary radiation exposure as well as additional time and manpower considerations.  !

Licensee Proposed Alternative Test The licensee will examine the remaining welds (or 75%) over the service lifetime of the plant. This would be 116 welds for the shutdown cooling system piping and 103 welds for the safety injection piping.  ;

Safety Evaluation

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Subparagraph IWC-2411 defines the selection criteria ,for ASE Class 2 welds  ;

subject to examination over the service lifetime of the facility. . The service  !

lifetime is divided into four 10-year intervals. The Code requires the i examination of 25% of Class 2 welds defined in IWC-2411 during each 10-year  ;

inspection interval.

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The examination requirements for ' Class 2 components were imposed by the -

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updating provisions of the regulation after Yankee Rowe had operated and l performed inspections for over ten years. The licensee raised the issue to  !

determine whether IWC-2411 requires the acceleration of Class 2 examinations  ;

to account for no examination during the first inspection interval. Table j IWC-2500 defines the examination requirements of components selected from i IWC-2400 during each interval. The licensee is performing the examination of j at least 25% of the welds during each interval. The population size, method, i and extent of examination change with Code editions. However, the regulation '

j requires that examination in each inspection interval is independent of previous intervals. The staff concludes that the licensee is meeting the Code  ;

requirement for the current interval and no relief is required.

CONCLUSION l q

For two of the relief requests reviewed, the staff concludes that the Code requirements are satisfied by the licensee's proposal and that relief is not required. For the remaining request, the staff has concluded pursuant to 10 CFR 50.55a (g)(6) that relief granted from the examination and testing )

requirements and the alternate methods imposed by this document provide  ;

reasonable assurance of system integrity, that granting of the relief where code requirements are impractical is authorized by law and will not endanger  :

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l life or property or the' common defense and security, and -is otherwise.in the pub 1h drterest considering the burden that could result.if they were imposed upon the facility. The relief granted remains in effect for the ten-year l inspection interval- ending on July 1,1991, .unless. revised or~ modified prior.to l that date. '

Dete: @N181237 Prir.cipal Contributor: S. Lee t

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