ML20212L179

Informs That as Result of Staff Review of Util Responses to GL 92-01,rev 1,suppl 1 & Suppl 1 Rai,Staff Revised Info in Rvid & Is Releasing Rvid Version 2

ML20212L179
Person / Time
Site:	Byron
Issue date:	10/05/1999
From:	Dick G NRC (Affiliation Not Assigned)
To:	Kingsley O COMMONWEALTH EDISON CO.
References
GL-92-01, NUDOCS 9910070206
Download: ML20212L179 (4)

Text

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U ,e 4 g i ~ UNITED STATES -

g y NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30e06 4001

.' g%, October'5, 1999

. . . . f' -

. Mr. Oliver D. Kingsley, President l Nuclear Generation Group

! . Commonwealth Edison Company Executive Towers West lli L 1400 Opus Place, Suite 500 Downers Grove, IL 60515

SUBJECT:

RESPONSE TO THE REQUEST FOR ADDITIONAL'INFORMATION TO GENERIC LETTER 92-01,' REVISION 1, SUPPLEMENT 1 - BYRON, UNIT 1 (TAC NO. MA0529)

Dear Mr. Kingsley:

)

On May 19,1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter 92-01, Revision 1, Supplement 1, " Reactor Vessel Structural Integrity," (GL) to holders of -

nuclear operating licenses, in issuing the GL, the staff requested addressees to:

i

, ' (1)- identify, collect and report any new data pertinent to the analysis of structural integrity of the reactor pressure vessels (RPVs) at their nuclear plants, and I L

(2) l assess the impact of that data'on their RPV integrity analysgs relative to the requirements of Sections 50.60 and 50.61 to Part 50 of Title 10 of the Code of Federal '

. Regulations (10 CFR 50.60 and 10 CFR 50.61), and to the requirements of Appendicea G and H to Part 50 of Title 10 of the Code of Federal Regulations (Appendices G and H to 10 CFR Part 50).

On August 17,1995, Commonwealth Edison Company (Comed) submitted its initial response to the GL and provided the requested information relative to the structural integrity 1 assessments for Byron, Unit 1. The staff evaluated the response to the GL and provided its conclusion relative to the response on August 29,1996. However, since the time of the staff's closure letter, the Combustion Engineering (CE) Owners' Group and the Babcock and Wilcox ]

(B&W) Owners' Group have each submitted additional data regarding the alloying chemistries of beltline welds in CE and B&W fabricated vessels. The additional alloying data were submitted in Topical Reports CE NPSD-1039, Revision 2 and CE NPSD-1119, Revision 1 for CE fabricated RPV welds, and BAW-2325, Revision 1 for B&W fabricated RPV welds. In addition, Chicago Bridge and Iron (CB&l) BWR data were submitted in Topical Report L BWRVIP-46. lb On July 1,1998, the staff issued a request for additional information (RAl) regarding any /

g revisions to the alloying chemistries for the beltline welds, Comed's assessment of surveillance data for the facility, pressure temperature (P.T) limits and pressurized thermal shock (PTS) p.p assessments for Byron, Unit 1. In general, with respect to the contents of the RAI, the staff 1 L requested that Comed reassess the alloying chemistries for the beltline welds and RPV I f- surveillance welds provided in Topical Report BAW-2325 and provide the impact of best I

estimate chemistries for the beltline RPV welds on the structural integrity assessments for the facility relative to the requirements of 10 CFR 50.60,10 CFR 50.61, and Appendices G and H

[ to 10 CFR Part 50, as applicable to the plant's licensing basis. 4 9910070206 991005 PDR- ADOCK 05000454 p PDR 3

6 O. Kingsley' 1-

. Comed provided its response to the staff's RAI on September 3,1998. As a result of the staff's review of the responses to GL 92-01, Revision 1; GL 92-01, Revision 1, Supplement 1, and the Supplement 1 RAI, the staff has revised the information in the Reactor Vessel Integrity

. Database (RVID) and is releasing it as RVID Version 2. It should be noted that there are some variations in the data included by the staff, and the corresponding values reported by Comed in its response to the GL 92-01, Revision 1, Supplement 1 RAl. The deviations between the data are explained in the reference sections for each Unit, or the individual screen notes (i.e., each forging, plate, and weld has a specific area for notes which is a new feature of the database).

The deviation between the submittal for Byron, Unit 1, and the staff's evaluation of the data in Capsule W is explained below.

When the chemistry factor (CF) for the intermediate shell forging (heat number 5P-5933) is calculated using surveillance data including data from capsule W which is analyzed in WCAP-15123 (January 1999), the present P-T limits and PTS evaluations are nonconservative  !

.with respect to neutron radiation embrittlement. Although two of the six surveillance data points l for this forging are not credible, both are within'the 2-sigma limits using Regulatory Guide (RG)

Position 1.1 (the predicted minus the measured delta RTndt value for one data point is equal to the 2-sigma limit of 34 degrees Fahrenheit). Therefore, since two of the data points are not ,

credible, the staff used surveillance data with the full margin to calculate RTprs. However, i RG 1.99, Revision 2 also permits the use of the CF from the tables in the guide when 1 surveillance data is not credible. Since intermediate shell forging (heat number SP-5933) is the limiting material, the credibility of surveillance data must be addressed in future submittals. We  ;

note that on July 12,1999, Comed transmitted revised Pressure Temperature Limit Reports for i Units 1 and 2. Upon completion of their review by the staff, we will provide you with any comments.

The new database diskettes are posted on the world-wide-web at a location which is linked to the NRC home page (http://www.nrc. gov /NRR/RVID/index.html). We recommend that Comed review this in' armation. Future submittals on P-T limits, PTS, or upper shelf energy (USE) ,

should reference the most current information.

' This closes the staff's efforts in regard to TAC No. MA0529. The staff appreciates your efforts in regard to this matter.

Sincerely, Or'iginal Signed By George F. Dick, Jr., Project Manager, Section 2 Project Directorate lli . l Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. STN 50-454 DISTRIBUTION- Docket File PUBLIC PD3 r/f 2 cc: See next page ACRS OGC M. Jordan, Rlli GVissing Alee, EMCB HConrad DOCUMENT NAME: G:\PDill-2\ byron \mpaMA0529.wpd Ta receive a copy of this document. IndicMb4n $e bor "C" = Copy without enclosures 4E" = Copy with orciosures "N" = No copy OFFICE PM:LPD3/l ,, 6 LLAMtD3 f./ SC1PD3 4 NAME GDick 'MM' t&loprh Afile6dio#/

DATE 10//4 /99 10/ T /99 ( M/(7b9 OFFICIAL EECORD COPY

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O. Kingsley Byron Station .

Commonwealth Edison Company Units 1 and 2 cc:

Regional Administrator, Region ill Mrs. Phillip B. Johnson U.S. Nuclear Regulatory Commission 1907 Stratford Lane 801 Warrenville Road Rockford, Illinois 61107 Lisle, Illinois 60532-4351 Attomey General Illinois Department of Nuclear Safety 500 S. Second Street Office of Nuclear Facility Safety Springfield, Illinois 62701 1035 Outer Park Drive Springfield, Illinois 62704 Commonwealth Edison Company Byron Station Manager Document Control Desk-Licensing 4450 N. German Chuich Road Commonwealth Edison Company Byron, Illinois 61010-9794 1400 Opus Place, Suite 400 Downers Grove, Illinois 60515 Commonwealth Edison Company Site Vice President - Byron Ms. C. Sue Hauser, Project Manager 4450 N. German Church Road Westinghouse Electric Corporation Byron, Illinois 61010-9794 Energy Systems Business Unit  !

Post Office Box 355 Mr. David Helwig Pittsburgh, Pennsylvania 15230 f

Senior Vice President {

Commonwealth Edison Company 1 Joseph Gallo Executive Towers West 111 Gallo & Ross 1400 Opus Place, Suite 900 1025 Connecticut Ave., N.W., Suite 1014 Downers Grove, Illinois 60515 j Washington, DC 20036 {

Mr. Gene H. Stanley i Howard A. Learner PWR Vice President Env;ronmental Law and Policy Commonwealth Edison Company Center of the Midwest Executive Towers West ll1 35 East Wacker Drive 1400 Opus Place, Suite 900 Suite 1300 Downers Grove, Illinois 60515 Chicago, Illinois 60601 Mr. Christopher Crane U.S. Nuclear Regulatory Commission BWR Vice President Byron Resident inspectors Office Commonwealth Edison Company 4448 North German Church Road Executive Towers West til Byron, Illinois 61010-9750 1400 Opus Place, Suite 900 Downers Grove, Illinois 60515 Ms. Lorraine Creek RR 1, Box 182 Manteno, Illinois 60950

! Chairman, Ogle County Board Post Office Box 357 Oregon, Illinois 61061 L 1

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,t 7e O. Kingsley Byron Station .

Commonwealth Edison Company Units 1 and 2 Mr. R. M. Krich

' Vice President - Regulatory Services Commonwealth Edison Company

- Executive Towers West ll1 1400 Opus Place, Suite 500 -

Downers Grove, Illinois 60515 Commonwealth Edison Company Reg. Assurance Supervisor- Byron 4450 N. German Church Road Byron, Illinois 61010-9794 Ms. Pamela B. Stroebei Senior Vice President and General Counsel Commonwealth Edison Company P.O. Box 767 Chicago, Illinois 60690-0767 e

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