ML20217K647

Requests That Util Provide Response to Encl RAI within 90 Days,In Order to Complete Response to Items 2,3 & 4 of GL 92-01,rev 1,suppl 1, Reactor Vessel Structural Integrity

ML20217K647
Person / Time
Site:	Cooper
Issue date:	04/24/1998
From:	Hall J NRC (Affiliation Not Assigned)
To:	Horn G NEBRASKA PUBLIC POWER DISTRICT
References
GL-92-01, GL-92-1, TAC-MA1185, NUDOCS 9805040057
Download: ML20217K647 (7)

Text

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[/parc%k UNITED STATES j

2 NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30086-4001

\*****p# April 24, 1998 Mr. G. R. Hom Sr. Vice President of Energy Supply Nebraska Public Power District 141415th Street Columbus, NE 68601

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION REGARDING REACTOR PRESSURE VESSEL INTEGRITY AT COOPER NUCLEAR STATION -(TAC NO.

MA1185)

Dear Mr. Hom:

Ger.oric Letter (GL) 92-01, Revision 1, Supplement 1 (GL 92-01, Rev.1, Supp.1), " Reactor Ves sel Structural Integrity" was issued in May 1995. This GL requested licensees to perform a review ol their reactor pressure vessel (RPV) structural integrity assessments in order to identify, collect, and report any new data pertinent to the analysis of the structural integrity of their RPVs and to assess the impact of those data on their RPV integrity analyses relative to the requirements of Section 50.60 of Title 10 of the Code of Federal Reaulations (10 CFR Part 50.60),10 CFR 50.61, Appendices G and H to 10 CFR Part 50 (which encompass pressurized thermal shock (PTS) and upper shelf energy (USE) evaluations), and any potential impact on low temperature overpressure (LTOP) limits or pressure-temperature (P-T) limits.

After reviewing your response, the NRC issued you a letter dated July 30,1996. In this letter we acknowledged receipt of your response, noted that additional RPV information may become available as a result of Owners Group efforts and requested that you provide us with the results of the Owners Groups' programs relative to your plant. We further indicated that a plant specific TAC Number may be opened to review this material. Following issuance of these letters, the BWR Vessel and intomals Project (BWRVIP) submitted the report " Update of Bounding Assessment of BWR/2-6 Reactor Pressure Vessel Integrity issues (BWRVIP-46)." This report included bounding assessments of new data from 1) the Combustion Engineering Owners Group (CEOG) database released in July 1997, which contains all known data for CE fabricated wolds in PWR and BWR vessels; 2) Framatome Technologies incorporated (FTI) analyses of Linde 80 welds which are documented in NRC Inspection Report 99901300/97-01 dated January 28,1998;

3) FTl's analysis of electro-slag welds which was referenced in a Dresden and Quad Cities P-T limits submittal dated September 20,1996; and 4) Chicago Bridga r:: iron quality assurance records. New data for one vessel fabricated by Hitachi was also included in the BWRVIP report.

The staff is requesting that you re-evaluate the RPV weld chemistry values that you have previously submitted as part of your licensing basis in light of the information presented in the CEOG, FTl and BWRVIP reports. The staff expects that you will assess this new information to determine whether any values of RPV weld chemistry need to be revised for your facility.

Therefore, in order to provide a complete response to items 2,3 and 4 of the GL, the NRC j requests that you provide a response to the enclosed request for additional information (RAl) l within 90 days of receipt of this letter. If a question does not apply to your situation, please I l indicate this in your RAl response along with your technical basis and, per GL 92-01, Rev.1, \ }

Supp.1, provide a certification that previously submitted evaluations remain valid, t t

9905040057 900424 PDR ADOCK 05000298 y( D '

PD __

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Mr. G. R. Hom 1 l

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! The information provided will be used in updating the Reactor Vessel Integrity Database (RVID). l Also, please note that RPV integrity analyses utilizing newly identified data could result in the l need for license amendments in order to maintain compliance with 10 CFR Part 50.60, and l Appendices G and H to 10 CFR Part 50, and to address any potentialimpact on P-T limits. If f additionallicense amendments or assessments are necessary, the attached requests that you provide a schedule for such submittals.

. If you should have any questions regarding this request, please contact James Hall at (301)-415-1336.

Sincerely, ORIGINAL SIGNED BY:

James R. Hall, Senior Project Manager Project Directorate IV-1 Division of Reactor Projects lil/lV Office of Nuclear Reactor Regulation I

Docket No. 50-298

Enclosure:

As stated cc: See next page DISTRIBUTION:

Docket File PUBLIC PD4-1 r/f J.Hannon C.Hawes ACRS OGC (15B18)

T. Gwynn, RIV J. Hall E. Adensam (EGA1)

Document Name: COOA1185.LTR 3 /

OFC PM/PD4-1 LA/PD4-1 D/P NAME JHall/vwN CHbN JHannon DATE Y/D/98 M 123/98 hMI98 OFFICIAL RECORD COPY' l

Mr. G. R. Hom The information provided will be used in updating the Reactor Vessel Integrity Database (RVID).

Also, please note that RPV integrity analyses utilizing newly identified data could result in the need for license amendments in order to maintain compliance with 10 CFR Par 150.60, and Appendices G and H to 10 CFR Part 50, and to address any potential impact on P-T limits. If additional license amendments or assessments are necessary, the attached requests that you provide a schedule for such submittals.

If you should have any questions regarding this request, please contact James Hall at (301)-415-1336.

Sincerely, nfL s ames R. Hall, Senior Project Manager

! Project Directorate IV-1 Division of Reactor Projects Ill/lV l Office of Nuclear Reactor Regulation Docket No. 50-298 i

l

Enclosure:

As stated cc: See next page 1

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i I

Mr. G. R. Hom

, Nebraska Public Power District Cooper Nuclear Station cc:

l Mr. John R McPhail, General Counsel Lincoln Electric System Nebraska Public Power District ATTN: Mr. Ron stoddard P. O. Box 499 Box 80869

, Columbus, NE 68602-0499 Lincoln, NE 68501 1

Nebraska Public Power District MidAmerican Energy ATTN: Mr. J. H. Swailes ATTN: Dr. William D. Leech, Manager-Nuclear Vice President of Nuclear Energy 907 Walnut Street P. O. Box 98 P. O. Box 657 j Brownville, NE 68321 Des Moines, IA 50303-0657 l

l Randolph Wood, Director

Nebraska Department of Environmental Nebraska Public Power District I

Control ATTN: Mr. B. L. Houston, Nuclear P. O. Box 98922 Licensing & Safety Manager Lincoln, NE 68509-8922 P. O. Box 98

Brownville, NE 68321 l Mr. Larry Bohlken, Chairman l Nemaha County Board of Commissioners Nemaha County Courthouse 1824 N Street Aubum, NE 68305 Senior Resident inspector U.S. Nuclear Regulatory Commission  !

P. O. Box 218 l l Brownville, NE 68321 l Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 Ms. Cheryl Rogers, LLRW Program Manager Division of Radiological Health Nebraska Department of Health 301 Centennial Mall, South P. O. Box 95007 i Lincoln, NE 68509-5007 Mr. Ronald A. Kucera, Department Director of Intergovemmental Cooperation )

Department of Natural Resources P.O. Box 176 Jefferson City, MO 65102 l

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REQUEST FOR ADDITIONAL INFORMATION REACTOR PRESSURE VESSEL INTEGRITY Section 1.0, Assessment of Best-Estimate Chemistry The staff recently received the BWRVIP report " Update of Bounding Assessment of BWR/2 4 Reactor Pressure Vessel Integrity issues (BWRVIP-46)".

Based on this information, in accordance with the provisions of Generic Letter 92-01, Revision 1, Supplement 1, the NRC requests the following:

1. An evaluation of the bounding assessment in the reference above and its applicability to the determination of the best-estimate chemistry for all of your RPV beltline welds. Based upon this reevaluation, supply the information necessary to completely fill out the data requested in Table 1 for each RPV beltline weld material. If the limiting material for your vessel's P-T limits evaluation is not a weld, include the information requested in Table 1 for the limiting material also.

With respect to your response to this question, the staff notes that some issues regarding the  !

evaluation of the data were discussed in a public meeting between the staff, NEl, and industry representatives on November 12,1997 A summary of this meeting is documented in a meeting summary dated November 19,1997, " Meeting Summary for November 12,1997, Meeting with i Owners Group Representatives and NEl Regarding Review of Responses to Generic Letter )

l 92-01, Revision 1 Supplement i Responses"(Reference 1). The information in Reference 1 l may be useful in helping you to prepare your response.

In addition to the issues discussed in the referenced meeting, you should also consider what  !

method should be used for grouping sets of chemistry data (in particular, those from weld  !

qualification tests) as being from "one weld" or from multiple welds. This is an important j consideration when a mean-of-the-means or coil-weighted average approach is determined to be  ;

the appropriate method for determining the best-estimate chemistry, if a weld (or welds) were -  ;

fabricated as weld qualification specimens by the same manufacturer, within a short time span, l using similar welding input parameters, and using the same coil (or coils in the case of tandem l arc welds) of weld consumables, it may be appropriate to consider all chemistry samples from I that weld (or welds) as samples from "one weld" for the purposes of best-estimate chemistry determination. If information is not available to confirm the aforementioned details, but sufficient evidence exists to reasonably assume the details are the same, the best-estimate chemistry should be evaluated both by assuming the data came from "one weld" and by assuming that the data came from an appropriate number of" multiple welds". A justification should then be provided for which assumption was chosen when the best-estimate chemistry was determined.

Section 2.0: P-T Limit Evaluation

2. If the limiting material for your plant changes or if the adjusted reference temperature for the limiting material increases as a result of the above evaluations, provide the revised RT,,, value for the limiting material. In addition, if the adjusted rte value increased, provide a schedule for revising the P-T limits. The schedule should ensure that compliance with 10 CFR 50 Appendix G is maintained.

ENCLOSURE

2-Reference i

1. Memorandum dated November 19,1997, from Keith R. Wichman to Edmund J. Sullivan, l

" Meeting Summary for November 12,1997, Meeting with Owners Group Representatives l and NEl Regarding Review of Responses to Generic Letter 92-01, Revision 1, l Supplement 1 Responses.'

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