ML20129F486

Submits Proposed Changes to Util ISI Program.Bases for Releif Requests IR-6 & IR-7,encl

ML20129F486
Person / Time
Site:	Seabrook
Issue date:	10/22/1996
From:	Diprofio W NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NYN-96066, NUDOCS 9610290137
Download: ML20129F486 (8)

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Seabrook, Nll 03874 (603) 474-9521 Thgrtgsglities System Docket No. 50-443 NYN-96066 United States Nuclear Regulatory Commission Attention: Document Control Desk Wa'shington, D.C. 20555 Seabrook Station ,

inservice Insnection Pronram Pursuant to 10CFR50.55a(g)(5), North Atlantic Energy Service Corporation (North Atlantic) hereby submits proposed changes to the North Atlantic Inservice Inspection Program.

North Atlantic submits the following requests for relief from specific requirements of the ASME Boiler and Pressure Vessel Code,Section XI for Seabrook Station.

Relief Request IR 6, " Residual Heat Removal Heat Exchanger Nozzle Welds" e Relief Request IR-7, " Reactor Vessel Closure Head Nuts" Similar relief from the ASME Section IX requirements for the Reactor Vessel Closure Head Nuts has been granted to Vermont Yankee.

The Inservice Inspection Program Plan, First Ten-Year Interval complies with the 1983 Edition with the Summer 1983 Addenda of ASME Section XI.

Enclosures I and 2 provide the bases for the relief requests. These enclosures also describe proposed alternative examinations that will be conducted in lieu of the Code required examinations to ensure system integrity and operational readiness. North Atlantic believes that the proposed alternative examinations are capable of providing an acceptable level of quality and safety while currently reducing hardship.

North Atlantic requests NRC review and approval of these relief requests by March 31,1997.

Should you have any questions regarding this matter, please contact Mr. Anthony M. Callendrello, Licensing Manager, at (603) 474-9521, extension 2751.

Very truly 'ou ,

s+CV /Adr 6" 9Og

" Willian/I. DiProfio / #

Station Dire /

l 9610290137 961022 PDR ADOCK 05000443 1 i

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United States Nuclear Regulatory Commission NYN-96066/Page 2 cc: H. J. Miller, Region Administrator A. W. De Agazio, Sr. Project Manager J. B. Macdonald, NRC Senior Resident Inspector l

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1 ENCLOSURE I TO NYN-96066 i

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, Enclosure 1 I North Atlantic Energy Service Corporation Seabrook Unit i First Ten-Year Inten al Relief Request Number IR-6

1. Components For Which ReliefIs Requested:

Two Residual lleat Removal lleat Exchanger Nozzle To Shell Welds

2. Component ID Numbers:

Rif E-9B NZA-B Rif E-9B NZB-B

3. ASME Code Class: 2

4. Examination Category: C-B, item C2.30

5. Code Requirement:

ASME B&PV Code Section XI,1983 Edition through Summer 1983 Addenda, Table IWC-2500-1, item No. C2.31 requires a surface examination. Item No. C2.33 requires a VT-2 visual examination of the nozzle to shell welds as well as evidence ofleakage examination per item No.

C2.33 Note 5.

6. Code Reauirement From Which ReliefIs Requested:

Relief is requested from performing the Code required surface examination, the VT-2 visual examination and evidence ofleakage examination as directed in Table IWC-2500-1, Item Nos.

C2.31 and C2.33 utilizing referenced Figure No. IWC-2500-4(c), and Item No. C2.33 Note 5.

7. Basis for Relief; The RilR IIcat Exchanger Nozzle configuration is such that it does not conform to the referenced examination Figure No. lWC-2500-4(c). The inside of the vessel is inaccessible and the reinforcing plate is on the inside. Furthermore, the reinforcing plate does not possess a telltale hole to verify evidence of leakage while the vessel is undergoing the system pressure test as required by item No. C2.33 Note 5.

8. Alternative Examinations:

• Perform a volumetric examination of the nozzle to shell welds.

Perform a 100% surface examination of the nozzle to shell welds.

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, Perform an inservice system leakage test and VT-2 visual examination per Table IWC-2500-1, Category C-li of the nozzle to shell welds.

9. Justification For the Grantino of Relief:

The Alternative Examinations meet and exceed the required examinations of Code Category C-B, item No. C2.30. It exceeds the requirements as volumetric examination is not required due to the inside of the vessel being inaccessible. The technicality is that the examinations can be performed, but the nozzle to shell configuration is such that they can not be performed in accordance with reference Figure IWC-2500-4(c) and Note 5 in Code Category C-B ltem No.

C2.30.

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Conclusion:

Based on the foregoing, North Atlantic believes that performing the Alternative Examinations provides reasonable assurance that unallowable inservice flaws have not developed in the subject RilR lleat Exchanger Nozzle to Shell Welds. Furthermore, performing the Alternative Examinations provides reasonable assurance that development of unallowable inservice flaws will be detected and repaired prior to return of the RiiR 11 eat Exchanger to service. Thus, an acceptable level of quality and safety will have been achieved, and public health and safety will not be endangered by allowing the proposed alternative examinations in lieu of the Code requirement.

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D ENCLOSURE 2 TO NYN-96066 L

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, Enclosure 2 North Atlantic Energy Service Corporation Seabrook Unit I l

First Ten-Year Interval l Relief Request Number IR-7 l i

1. Components For Which Relief Is Reauested:

i Fifty Four (54) Reactor Vessel Closure Head Nuts l

2. Comoonent ID Numbers:

RC RPV NUT I - 54

3. ASME Code Class: 1

4. Examination Categorv: B-G-1, item B6.10  ;

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5. Code Reauiremcal:

l ASME B&PV Code Section XI,1983 Edition through Summer 1983 Addenda, Tab;e IWB-2500-1, item No. B6.10 requires a surface examination of 100% of the surfaces.  !

1 6, Code Reauirement From Which Relief is Reauested:

Relief is requested from performing the Code required surface examination on the above 5 identified Reactor Vessel Closure Head Nuts. -

7. Basis for Relief: l The Reactor Vessel Closure Head Nut configuration is such that only the outside surface of the nut is readily accessible for surface examination. In addition, the 1983 Edition of ASME Section XI through Summer 1983 Addenda does not contain acceptance criteria for this examination.

The 1992 Edition of ASME Section XI requires a VT-1 visual examination for reactor vessel  !

nuts and provides acceptance criteria.  !

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8. Alternative Examination:

. Perform a VT-1 visual examination as specified in Table IWB-2500-1, item B6.10 of the 1992 l' Edition of ASME Section XI, and the acceptance criteria ofIWB-3517.  ;

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9. Justification For The Granting of Relief:

l The 1992 Edition of ASME Section XI describes the relevant conditions which require )

correction for reactor vessel nuts. A VT-1 visual examination will reveal any of these relevant ,

4 conditions as readily as a surface examination. 1 1

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Conclusion:

Based on the foregoing, North Atlantic believes that performing a VT-1 visual-examination in accordance with the 1992 Edition of ASME Section XI will provide reasonable assurance that unallowable inservice flaws have not developed in the subject reactor vessel nuts or that they will be detected and repaired prior to return of the reactor vessel to service. Thus, an acceptable level of quality and safety will have been achieved, and public health and safety will not be endangered by allowing the proposed alternative examination in lieu of the Code requirement.

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