ML20237D566

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Informs That Util Intends to Implement,During Upcoming 17R Outage,Installation of Core Support Plate Wedges.Licensee 10CFR50.59 SE & Calculations,Encl,Which Support Implementation of Subject Mod
ML20237D566
Person / Time
Site: Oyster Creek
Issue date: 08/25/1998
From: Rone A
GENERAL PUBLIC UTILITIES CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20237D567 List:
References
1940-98-20423, NUDOCS 9808270005
Download: ML20237D566 (2)
v • d • e


Text

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m l GPU Nuclear, Inc.

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(. One Upper Pond Road NUCLEAR .

Parsippany. NJ 070541095 Tei 20i ais-7000 August 25, 1998 1940-98-20423 i

U. S. Nuclear Regulatory Commission Attn: Document CentrolDesk Washington,DC 20555 l

Gentlemen:

Subject:

Oyster Creek Nuclear Generating Station (OCNGS) ,

Docket No. 50-219 f/ l Facility Operating license No. DPR-16 I' l

Core Support Plate Wedge 17R Outage Modification GPU Nuclear, in compliance with BWR Vessel and Intemals Project (BWRVIP) utility i commitments, intends to implement, during the upcoming 17R Outage, the installation of core I support plate wedges to structurally replace the lateral resistance provided by the rim holddown bolts. By selecting this recommendationoption, as provided by BWRVIP-25, GPU Nuclear will  !

not need to inspect the core support plate holddown bolts. This modification, described in detail in Attachment 1, addresses the design criteria developed by the BWRVIP for top guide / core support I plate modifications,BWRVIP-50, including specific design criteria and requirements for wedge-  !

type modifications. The design for the Oyster Creek core support plate wedge modification addresses the potential degraded conditions of the core support plate which affect the core support

' plate lateral alignment as defined in BWRVIP-25.

The modification is consistent with the current plant licensing basis and ensures that the core

, support plate will be maintained in the lateral position and its operational and safety functions are l

satisfied even if the core support plate lateral restraint components fail (i.e., rim holddown bolts).

The modification design maintains the safety margin and functional capability of the core shroud (i.e., to withstand the localized wedge loading conditions). Attachment 2 provides GPU Nuclear's 10 CFR 50.59 Safety Evaluation which reviews and evaluates the :afety consequences for

[(

implementationof this modification and also documents the basis for the determinationthat this P A O 19 P PDR y J

I activity does not involve an unreviewed safety question. GPU Nuclear has determined that installation of the wedges may be done without prior NRC approval but operation with this modification in place will require NRC approval since the modification is not included under the ASME Boiler and Pressure Vessel Code,Section XI, definition for modification and replacement but rather is developed as an alternative pursuant to 10 CFR 50.55a(a)(3).

Attachment 1 provides the comprehensivedesign report for this modification,MPR Associates Report MPR-1957, " Design Submittal for Oyster Creek Core Plate Wedge Modification". It should be noted that MPR-1957, Section 8.2.2, provides proposed inspection activities for subsequent refueling outages. These proposed activities are contingent upon future refueling outages (18R, 19R, etc.) at Oyster Creek taking place. No future refueling outages are currently planned to occur at Oyster Creek after the upcoming 17R Outage.

To further assist in the staff review, Attachment 3 provides four supporting MPR Associates calculationsreferenced in MPR-1957. These are MPR 083-261-BRL-1,MPR 083-261-BRL-2, MPR 083-261-BRL-3,and MPR 083-248-CBS-01,Rev.1.

GPU Nuclear recognizes the short timeframe for review and the burden this may place on the NRC Staff. This short timeframe is a result of the BWRVIP's May,1998 issuance of specific design criteria and requirements for. wedge-type modifications (B WRVIP-50) which necessitated this 17R Outage activity. However, GPU Nuclear does request expedited review and approval of this ]

modification, ideally, prior to the start ofinstallation during the 17R Outage. The 17R Outage is i I

. currently scheduled to begin September 26,1998 and last 35 days with installationof the pmposed modification beginning on or about October 3,1998.

If you have any questions or comments on this matter, please contact Ron Zak, Corporate Regulatory Affairs at (973) 316-7035.

Very truly yours,

.1.Rone Vice President and Director Engineering c: Administrator, Region 1 SeniorResidentInspector i Oyster Creek NRC Project Manager o- - - - - - - - - - - _ . - - - - - - - - - - - - - _ - - _ _ _ - - - - - - - _ _ _ _

L  ?

{ GPU Nuclear. inc.

( .

One Upper Pond Road NUCLEAR Parsippany, NJ 070541095 Tel 201316 7000 August 25, 1998 1940-98-20423 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington,DC 20555 Gentlemen:

Subject:

Oyster Creek Nuclear Generating Station (OCNGS)

Docket No. 50-219 Facility Operating License No. DPR-16 Core Support Plate Wedge 17R Outage Modification GPU Nuclear,in compliance with BWR Vessel and Intemals Project (BWRVIP) utility commitments, intends to implement,during the upcoming 17R Outage, the installation of core support plate wedges to structurally replace the lateral resistance provided by the rim holddown bolts. By selecting this recommendationoption, as provided by BWRVIP-25,GPU Nuclear will not need to inspect the core support plate holddown bolts. This modification,describad in detail in Attachment 1, addresses the design criteria developed by the BWRVIP for top guide / core support plate modifications,BWRVIP-50, including specific design criteria and requirements for wedge-type modifications. The design for the Oyster Creek core support plate wedge modification addresses the potential degraded conditions of the core support plate which affect the core support l plate lateral alignment as defined in BWRVIP-25. {

The modification is consistent with the current plant licensing basis and ensures that the core support plate will be maintained in the lateral position and its operational and safety functions are satisfied even if the core support plate lateral restraint components fail (i.e., rim holddown bolts).

The modification design maintains the safety margin and functional capability of the core shroud f (i.e., to withstand the localized wedge loading conditions). Attachment 2 provides GPU Nuclear's 10 CFR 50.59 Safety Evaluation which reviews and evaluates the safety consequences for implementationof this modification and also documents the basis for the determination that this J

g n ,

activity does not involve an unreviewed safety question. GPU Nuclear has determined that installation of the wedges may be done without prior NRC approval but operation with this modificationin place will require NRC approval since the modification is not included under the ASME Boiler and Pressure Vessel Code,Section XI, definition for modification and replacement but rather is developed as an alternative pursuant to 10 CFR 50.55a(a)(3).

Attachment I provides the comprehensive design report for this modification,MPR A.aociates Report MPR-1957," Design Submittal for Oyster Creek Core Plate Wedge Modification". It should be noted that MPR-1957, Section 8.2.2, provides proposed inspection activities for subsequent refueling outages. These proposed activities are contingent upon future refueling outages (l 8R, 19R, etc.) at Oyster Creek taking place. No future refueling outages are currently planned to occur at Oyster Creek after the upcoming 17R Outage.

To further assist in the staff review, Attachment 3 provides four supporting MPR Associates calculations referenced in MPR-1957. These are MPR 083-261-BRL-1,MPR 083-261-BP1-2, MPR 083-261-BRL-3,and MPR 083-248-CBS-01,Rev.1.

GPU Nuclear recognizes the short timeframe for review and the burden this may place on the NRC Staff. This short timeframe is a result of the BWRVIP's May,1998 issuance of specific design criteria and requirements for wedge-type modifications (BWRVIP-50)which necessitated this 17R Outage activity However, GPU Nuclear does request expedited review and approval of this modification, ideally, prior to the start ofinstallation during the 17R Outage. The 17R Outage is currently scheduled to begin Sept :mber 26,1998 and last 35 days with installation of the proposed modification beginning on or about October 3,1998.

If you have any questions or comments on this matter, please contact Ron Zak, Corporate Regulatory Affairs at (973) 316-7035.

Very truly yours, s ,

.1.Rone Vice Presidentand Director Engineering L

f c: Administrator, Region I l Senior ResidentInspector Oyster Creek NRC Project Manager L

C -

ATTACHMENT 1 MPR Associates Report MPR-1957,

" Design Submittal for Oyster Creek Core Plate Wedge Modification" I

I

.

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