ML20149G871

Request for Addl Info Re Second 10-yr Interval Inservice Insp Program Plan

ML20149G871
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	02/18/1988
From:	NRC
To:
Shared Package
ML20149G859	List: ML20149G855 ML20149G871
References
FOIA-88-86 NUDOCS 8802180444
Download: ML20149G871 (7)

Text

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VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271 Request for Additional Information - Second 10-Year Interval inservice InsDection Program Plan 1 Scepe/ Status of Review Throughout the service life of a water-cooled nuclear power facility, 10 CFR 50.55a(g)(4) requires that components (includino supports) which are classified as American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1 Class 2, and Class 3 neet the requirements, except design and access provisions and 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, geonetry, and j materials of construction of the components. This section of the regulations also requires that inservice examinations of components and systen pressure tests conducted during the second 120-month inspection interval shall comply with the requirenents in the latest edition and addenda of the Code incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the second 120-month inspection '

intervale sub.iect to the limitations and modifications listed therein.  ;

The components fincluding supports) may neet requirements set forth in subsequent editions and addenda of this Code which are incoronrated by l reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein. The Licensee, Vermont Yankee Nuclear Power '

Corporation, has prepared the Inservice Inspection (ISI) Program Plan to meet the requirements of the 1980 Edition, Winter 1980 Addenda (80W80) of the ASME Code Section XI except that the extent of examination for Code Class 1 and 2 piping welds has been determined by the 1974 Edition through Sumer 1975 Addenda (74575). The second 10-year inspection interval began November 30, 1982 and ends November 30, 1992.

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As required by 10 CFR 50.5'ia(g)(5), if the licensee determines that certain Code examination requirements are impractical and relief is requested, the licensee shall submit infomation to the Nuclear Reaulatory Comission (NRC) to support that determination.

Revision 8 of the Vermont Yankee Nuclear Power Station Second 10-year Interval ISI Program Plan, including the requests for relief from the ASME Code Section XI requirements which the Licensee has deternined to be impractical, has previously been reviewed and evaluated in the "Vermont Yankee Nuclear Power Station Safety Evaluation Report 2nd Ten-Year Interval Inspection Program and on Requests for Relief from Certain Requirements" dated February 10, 1987. In this Safety Evaluation Report !

(SER), the NRC determined that Revision 8 of the ISI Program Plan was acceptable for implementation and granted, conditionally granted, or denied the reovests for relief.

Revisinn 9 of the ISI Program Plan was subsequently prepared by the Licensee due to extensive facility modifications and the NRC approval of Amendment #99 to the Vermont Yankee Technical Specifications.

The staff has reviewed the available information in the Vermont Yankee Nuclear Power Station Second 10-year Interval ISI Program Plan, Revision 9, submitted July 1, 1987, including the requests for relief from the ASME Code Section XI requirements which the Licensee has determined to be ircractical.

?. Additional Infomation Required Based on the above review, the staff has concluded that the following infomation and/or clarification is required in order to complete the review of the ISI Program Plan:

A. The following exemptions were previously denied in the NRC's February 10, 1987 SER:

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Exemption Exe@ tion Number System nr Conoonent Criteria 2 RCIC System Discharge Piping IWC-lPP0(c) 3 RCIC System Steam Supply Piping and IWC-1220(c)

Condensate Handling Equipment and Piping 4 RCIC System Lube 011 Cooler and Piping IWC-1?20(c) 6 SLC System Discharge Pipinq IWC-1220(c) 7 Service and Instrument Air Systems IWC-1220(c) .

8 Sampling System IWC-1220(c) 9 CAD / Nitrogen Inerting System IWC-1220(c) 12 HPCI System Lube Oil Cooler and Piping IWC-1720(c) 13 HPCI System Condensate Handling Equipment IWC-1220(c) and Piping 14 HPCI Test loop to Torus IWC-1220(c) 15 Reactor Water Cleanup System IWC-1220(c) 16 CRD Pipino (except Scram Discharge IWC 1220(c)

Instrument Volumes and Headers) 17 Redwaste System IWC-1220(c)

?1 RRR Lines as follows:

RHR-4A IWC-1220(c)

RHR-11 IUC-1220(c)

RHR-13A through D IWC-1270(c)

RHR-16 IWC-1220(c)

RHR-21 IWC-1220(c)

RHR-22 IWC-1720fe)

RHR-?4A and B IWC-1220(c)

RHR-25 IWC-1220fe)

RHR-34A IWC-1220(c)

RHR-35A IWC-12?O(c)

RHR-36A IWC-1220(c)

RRR-38A and B IWC-1220(c)

RHR-44A through D IWC-1220(c)

RHA ASA through D IWC-1220(c)

The Licensee has claimed these same exemptions in Revision 9 of the ISI '

Program Plan. The Licensee should not be using the control of water  :

chemistry exemption of IWC-1220(c). The control of water chemistry to minimize stress corrosic.n described in paragraph IWC-1220(c) of the 1974 Edition through the Summer 1975 Addenda of Section XI of the ASHi Code is not an acceptable basis for exempting components from examination because practical evaluation, review, and acce9tance standards cannot be 4

defined. Therefore, examination shou'id be included for any components for which exemption is selected by the Licensee under paragraph I i

IPC-1220(c) of the 1974 Edition and Addenda of Section XI of the ASME Code. Verify that the chemistry control exclusion will not be used and that the IS! Program Plan will be revised to include examinations for l these components, as applicable.

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4 B. The staff notes that the Licensee is not performing volumetric examination of any of the Class 2 piping welds in the RHR System.

Paracraph 10 CFR 50.55s(b)(2)(iv) reouires that ASME Code Class ? piping welds in the Residual Heat Renoval (RHR), Emergency Core Coolino (ECC),

and Containment Heat Removal (CHR) systems shall be examined. These systems should not be completely exempted from inservice volumetric examination based on Section XI exclusion criteria contained in IWC-1220. Later editions and addenda of the Code require volumetric examination of Class 2 piping welds greater than or equal to 3/8-inch nominal wall thickness for piping greater than 4-inch nominal pipe size (NPS). The staff has previously determined that a 7.5% augmented volumetric sample constitutes an acceptable resolution at similar plants.

Verify that volumetric examination will be performed on at least a 7.5%

sample of the Class 2 piping welds in the RHR System.

C. Review of the ISI Program Plan for the Control Rod Drive (CDR) scram discharge volume (SDV) piping shows that a total of four of the 6-inch

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schedule 80 Class 2 piping welds are scheduled to receive surface examination and that none of the 10-inch schedule 80 Class 2 piping welds are scheduled to receive examinations. The NRC established the position in NUREG-0803, "Generic Safety Evaluation Report Regarding Integrity of BWR Scram System Piping," that licensees for BWR plants should perform periodic inservice inspection of the SDV system to meet the requirements for Class 2 pipino in Section XI of the ASME Code.

Because the SDV piping is designed and fabricated according to the requirements of ASt1E Section III Class 2 and because of its importance in echieving the scram function, it should, as a minimum, be subjected to the ISI requirements for Class 2 piping in ASME Code Section XI and the recomendations of NUREG-0803. Verify that the requirements of ASME Code Section XI and the recomendations of NUREG-0803 will be incorporated in i

-S-the CRD section of the Vernont Yankee Nuclear Power Plant Second Ten-Year Interval ISI Progran Plan.

D. The 6-inch branch pipe connection welds in the Main Steam System are listed as ASME Code Item No. 89.3? on pages I-69 and I-70 of the ISI Procram Plan. Since these welds are greater than 4 inches NPS, they should be listed as Item No. B9.31. Verify that the Item Number will be chanced. Also, why are these 6-inch NPS Iten No. 99.31 welds in the Main Steam System and the 28-inch NPS Item No. 89.31 welds in the Recirculatinn System excluded fron volumetric and surface examinations during the second inspection interval?

E. The Licensee listed 105 Item No. B9.11 Class 1 piping welds (Item No.

B4.5 in 74575) that are scheduled to be examined during the second inspection interval in Revisinn 8 of the ISI Procram Plan. In Revision 9 of the ISI Program Plan, there appear to be only 81 Item B9.11 Class 1 piping welds scheduled for examination. Also, it appears that the examination samples for item No. B9.11 piping welds in the Recirculation, Reactor Water Cleanup, and Core Spray Systems have been reduced. Discuss and ,iustify why the examinatinn samples have been reduced.

F. Provide a revised listing of the Class 1 and ? components to be examinsd

- durino the second inspection interval which includes the welds added to

the ISI Program Plan as a result of itens A, B C, D, and E above. Also, provide the applicable isometric drawings showing the welds added to the second interval inspection schedule.

G. Provide Inspection Sumary Tables for both Class 1 and Class 2 components similar to those included in Revision A to aid in the review of Revisinn 9 of the ISI Program Plan.

H. Address the degree of compliance with each of the following:

Regulatory Guide 1.150; NUREG-0312 NUREG-0313; NUREG-0619; and NUREG-0800, Section 3.6.1. Discuss any other auomented examinations that will be performed during the second 10-year interval.

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!. Provide a complete list of ultrasonic calibration blocks, includinn identifications, material specifications, and sizes.

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J. With regard to Request for Relief B-1 on the reactor pressure vessel circumferential and longitudinal shell welds, the procedure for the examination of these welds is currently under review by the reculatory staff. Identify those welds which could be examined if the insulation is remved.

K. In the Licensee's Auoust 1, 1986 response to Question No. 1 of the NRC's  ;

May 27, 1986 request for additional information (RAI) with regard to Relief Request B-2, the Licensee states: "At the tim of program i submittal, no belt line repairs could be identified." It was concluded, i however, that if repairs were later identified, these welds would I certainly not be accessible for inspection. The relief request was therefore submitted. Since that time, all construction records have been  !

, reviewed and it is determined that no "repair welds" were performed in l

) this area. This Relief Request is no longer needed and Relief Request l B-? will be removed from the program in the next revision." Why was l Relief Request B-2 not deleted from Revision 9 of the ISI Program Plan? l

! L. In the Licensee's August 1, 19R6 response to nuestion No. 4 of the NRC's l -

May 27, 19R6 RAI with regard to Relief Request B-6, the Licensee states:

"Vermont Yan'.ee is not requesting relief for any piping that exceeds the code exemption limited of 3 inches and smaller, further Vermont Yankee has connitted to the 80W80 Edition and will meet IWF-2510(a). Relief Request B-6 will be removed from this program in Revision 9, which is l.

scheduled to be submitted to the NRC by Deceder 31, 1986." Why was Relief Request B-6 not deleted from Revishn 9 of the ISI Program Plan?

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'M. In addition to not deleting from Revision 9 of the ISI Program Plan relief requests that have previously been withdrawn by the Licensee,

relief requests that were previously denied or determined to be not required in the NRC's February 10, 1987 SER were also not deleted l

a

o from Revision 9 of the ISI Program Plan. At present, the staff has no reason to change its position on the relief requests that were denied in the February 10, 1987 SER. The Licensee should provide the following and revise the ISI Program Plan accordingly:

i) revised relief requests or a table showing the status of the relief ,

requests (e.o., withdrawn and deleted; denied and deleted; denied but submitting explicit additional ,iustification; etc.);

ii) address any changes made to the relief requests from Revision 8 to Revision 9; and 111) note any new relief requests that were not included in Revision 8 of the ISI Program Plan or were not evaluated in the February 10, 1987 SER.

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