ML20094N430

Responds to GL 92-01,Rev 1,Suppl 1, Rv Structural Integrity

ML20094N430
Person / Time
Site:	Point Beach
Issue date:	11/20/1995
From:	Link B WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-92-01, GL-92-1, VPNPD-95-094, VPNPD-95-94, NUDOCS 9511280041
Download: ML20094N430 (3)

Text

-- - _ - _ - - - _ _ _ - _ _ --__-

'jI [.l ,

Wisconsin Electnc POWER COMPANY

' 231 W M,chgort PO Box 2046. Mhroukee. WI 5320b2046 - (414)221-2345

,VPNPD-95-094 November 20, 1995 Document Control Desk.

US NUCLEAR REGULATORY COMMISSION Mail Station P1-137 Washington, DC 20555 Ladies / Gentlemen DOCKETS 50-266 AND 50-301

. RESPONSE TO GENERIC LETTER 92-01, REVISION 1. SUPPLEMENT 1 POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Nuclear Regulatory Commission Generic Letter 92-01, Revision 1, Supplement 1,

" Reactor Vessel Structural Integrity," dated May 19, 1995, was issued to require h addressees to identify, collect, and report any new data pertinent to analysis of structural integrity of their reactor pressure vessels (RPVs). It also requires an assessment of the impact of this new data on RPV integrity analyses relative to the requirements of Section 50.60 of Title 10 of the code of Federal Regulations (10 CFR 50.60), 10 CFR 50.61, Appendices G and H to 10 CFR 50, and any potential impact on low temperature overpressure (LTOP) limits or pressure-temperature (P-T) limits.

The Generic Letter supplement requires that addressees provide the following information by August 17, 1995:

1)' A description of those actions taken or planned to locate all data relevant to the determination of RPV integrity, or an explanation of why the existing data base is considered complete as previously

- submitted.

The supplement also requires the following information to be provided by November 20, 1995 p 1) An assessment of any change in'best-estimate chemistry based on m

consideration of all relevant data, t t 3 '2) A determination of the need for use of the ratio procedure in accordance with the established Position 2.1 of Regulatory

-Guide 1.99, Revision 2, for those licensees that use

'h surveillance data to provide a basis for the RPV-integrity.

l" h I.l- 3) evaluation.

~

A written report providing any newly acquired data as specified above and:(1) the results.of'any-necessary revisions to the evaluation of gg -RPV integrity in accordance with the requirements of 10 CFR 50.60, gg 10 CFR 50.61, Appendices G and H to 10 CFR Part 50, and any potential

), lg  ; impact on.the LTOP or P-T limits in the Technical Specifications or -.

s.

l ag Ir y (2) a certification that previously submitted evaluations remain valid. f ihhi e Revised evaluations and. certifications should~ include consideration of 0 p;

-Position:2.liof Regulatory Guide 1.99, Revision 2, as applicable, and.

l any new' data.. J v[}

A.wasWingofHimwsht EergCapnun

t .

Document Control Desk November 20, 1995 Pa'ge 2 Wisconsin Electric (WE) provided its response to Requirement 1 of this Generic Letter Supplement for Point Beach Nuclear Plant Units 1 and 2 on August 16, 1995.

This letter provides the responses to Requirements 2, 3, and 4 for Point Beach I Units 1 and 2.

1 Reauirement 2 i

I The B&W Owners Group (B&WOG) Reactor Vessel Working Group has reviewed all available data sources for B&W fabricated reactor vessels and concluded that all available data have been previously considered by the B&WOG in establishing chemistry values for B&W fabricated reactor vessel welds. The results of this l review are included in BAW-2257, Revision 1, " Response to Generic Letter 92-01, j Revision 1, Supplement 1," which was submitted to the NRC by the B&WOG i.n Letter OG-95-1552 which was dated November 1, 1995.

WE has reviewed the pertinent data available from the B&WOG and from the I Westinghouse owners Group (WOG) Materials Subcommittee. Based on consideration of all relevant data there is no change in the best-estimate chemistry for the Point Beach Unit 1 RPV materials.

l In addition to data available from the B&WOG and WOG for Point Beach Unit 2, WE j l has also obtained some data from the Combustion Engineering-Reactor Vessel Group

and from Baltimore Gas and Electric Company (BG&E). The BG&E data was provided q I to the NRC in a letter from Robert E. Denton to the Document control Desk, l

" Request for Approval of Updated Values of Pressurized Thermal Shock (PTS) f Reference Temperatures (RTPTS) Values (10 CFR 50.61)," dated July 21, 1995.

Based on consideration of this data, the best-estimate chemistry for weld heat 21935 has changed for Point Beach Unit 2. For weld heat 21935, the best estimate  ;

copper is 0.17% and the best estimate nickel is 0.72%.

As discussed in our August 16, 1995, response to the Generic Letter Supplement, an effort to identify all remaining relevant data for weld heat 21935 is being conducted by the Combustion Engineering Owners Group-Reactor Working Group (CEOG-RVWG). This data is expected to be availablo in 1997. This data and an evaluation of its effect on reactor vessel integrity will be provided to the NRC at that time.

There is no change in the best-estimate chemistry for any other Point Beach Unit 2 RPV materials based on consideration of all relevant data.

Reauirement 3 Wisconsin Electric does not use weld surveillance data in its determination of reactor vessel integrity for Point Beach Units 1 and 2. Therefore, the ratio procedure in accordance with the established Position 2.1 of Regulatory Guide 1.99, Revision 2 is not applicable to Point Beach Units 1 and 2.

}l.** .

4 Document' control Desk' Nopember 20, 1995 Page 3 Raouirement 4 No additional data is available for the RPV materials for Point Beach Unit 1.

All previously docketed evaluations for Point Beach Unit i remain valid.

Some additional data for weld heat 21935 was obtained for Point Beach Unit 2.

.This data demonstrates that the weld chemistry values for the intermediate-to-upper shall circumferenti'al weld used by WE in previously submitted evaluations were conservative. No additional data is available for the other reactor vessel materials for Point Beach Unit 2. Therefore, all previously docketed evaluations l for Point Beach Unit 2 remain valid.

As discussed above, and effort to identify all remaining additional relevant data for weld heat 21935 is being conducted for Point Beach Unit 2 by the CEOG-RVWG. '

This data is expected to be available in 1997. This data and an evaluation of

.its effect on reactor vessel integrity will be provided to the NRC at that time.

If you have any questions or require additional information, please contact us.

Sincerely,

. Cn. ,l j Bob Link Vice President Nuclear Power l JRP cc: NRC Resident Inspector NRC Regional Administrator, Region III 1

l

\

m