ML20087K477
| ML20087K477 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 08/17/1995 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-92-01, GL-92-1, NLS950174, NUDOCS 9508230319 | |
| Download: ML20087K477 (5) | |
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GENERAL OFFICE t e=
P.O. BOX 499. COLUMBUS, NEBRASKA 68602-0499 N'ebraska Public Power District
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CUY R. HORN Vice-Presitent, Nuclear
( 0 2) 563-5518 1
NLS950174 I
August 17,1995 l
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l U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
90-Day Response to Generic Letter 92-01, Revision 1, Supplement i Reactor Vessel Structural Integrity l
Cooper Nuclear Station, NRC Docket 50-298, DPR-46
References:
1.
NRC Generic Letter 92-01, Revision 1, Supplement 1, dated May 19,1995,
" Reactor Vessel Structural Integrity."
2.
letter from J. T. Beckham, Jr. (BWRVIP) to NRC dated August 10,1995, "BWRVIP Response to NRC Generic Lctter 92-01, Revision 1, Supplement 1, Reactor Vessel Structural Integrity."
The Nebraska Public Power District (District) hereby provides its response for Cooper Nuclear Station (CNS) to the 90-day reporting requirements specified in Generic letter 92-01, Revision 1, Supplement I (Reference 1). Generic letter 92-01, Revision 1, Supplement I (Supplement) requires licensees to provide within 90 days, a description of actions taken or planned to locate all data relevant to the determination of reactor pressure vessel integrity, or an explanation of why the existing database is considered complete as previously submitted, i
The NRC issued the Supplement as a result of their review of licensee responses to Generic Letter 92-01, Revision 1, which indicated that some licensees may not have considered all relevant available material data in preparing their responses, and ultimately, in assuring the integi f h i reactor vessels. Consequently, the NRC issued the Supplement to ensure, d,
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.U. S. Nuclear Regulatory Commission August 17,1995 Page 2 of f I
through licensee review and evaluation of all relevant data, that the conclusions reached concerning reactor vessel structural integrity were still valid.
The District is a participant of the Boiling Water Reactors Vessels Internals Project (BWRVIP).
By letter dated August 10,1995 (Reference 2), the BWRVIP submitted its action plan to develop a generic BWR response to the information requests contained in the Supplement. As discussed in that letter, the BWRVIP stated that it would not be able to complete the research and evaluation required to obtain all of the requested information within the six month reporting requirement specified in the Supplement. However, the BWRVIP stated it would:
By November 20,1995, review and evaluate information in available industr3. itabases, address any inconsistencies identified, and provide the interim basis for ensurii.c idequate vessel structural integrity; By November 20,1995, request proposals from vessel fabricators to 1) identify vessels
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which they have fabricated that have the same material,2) retrieve and document all additional data relevant to vessel integrity on each material, or 3) verify that no additional data is available; Coordinate with the NEl RPV Integnty Data Task Force the development of a standard industry method for assessing changes in vessel material best estimate chemistry (this is expected to take more than a year to complet::);
Provide an evaluation of the need for use of the ratio procedure established in Position 2.1 of NRC Regulatory Guide 1.99, Revision 2; and Evaluate the impact of vessel material variability on BWR Upper Shelf Energy (USE) compliance, and specifically evaluate any impact to the BWR Owners' Group Equivalent Margins Analysis performed to address compliance with 10 CFR 50 Appendix G.1' As a member of the BWRVIP, the District will participate in these efforts and endorses that generic response (Reference 2). While the BWRVIP believes it will take at least 24 months to complete the effort required to identify and evaluate all information relevant to BWR vessel integrity, the BWRVIP committed to provide by November 20,1995, an assessment using preliminary data to demonstrate adequate margins exist in the near term in BWR Pressure / Temperature (Irr) Curves and in the USE equivalent margin analysis. The District, as a panicipant, will assemble the information requested in the Supplement in accordance with the schedule developed by the BWRVIP.
1.
Mehta, et. al.,"10 CFR 50 Appendix G Equivalent Margin Analysis for Low Upper Shelf Energy in BWIU2 Through BWR/6 Vessels," GE Report NEDO-32205-A, Revision 1, February 1994.
U. S. Nuclear Regulatory Commission August 17,1995 Page 3 of f For the interim, the District has conservatively re-evaluated CNS compliance with the 10 CFR 50 Appendix G fracture toughness requirements based on vessel weld material chemistry values which bound chemistry values recently published by ABB/ Combustion Engineering (ABB/CE),
the manufacturer of the CNS reactor vessel. This evaluation provides additional basis for demonstrating that CNS will remain in compliance with reactor vessel fracture toughness requirements until completion of the BWRVIP cffort.
Please contact me if you require any further information on this matter.
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' 11. orn Vice President - Nuclear GRH:MJB cc:
Regional Administrator USNRC - Region IV Resident Inspector Cooper Nuclear Station NRC Project Manager USNRC - Office of Nuclear Reactor Regulation NPG Distribution t
U. S. Nuclear Regulatory Commission August 17,1995 Page 4 of 4 STATE OF NEBRASKA )
)ss PLATTE COUNTY
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G. R. llorn, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this response on behalf of Nebraska Public Power District; and that the statements contained herein are tme to the best of his knowledge and belief.
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- d. R. Iforn Subscribed in my presence and sworn to before me this
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-l LIST OF HRC COMMITMENTS l ATTACHMENT 3 l
Correspondence No: NLS950174 The following table identifies those actions committed to by the District in this document.
Any other actions discussed in the submittal represent intended or planned actions by the District.
They are described to the NRC for the NRC's information and are not regulatory commitments.
Please notify the Licensing Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.
COMMITTED DATE COMMITMENT OR OUTAGE The District, as a participant, will assemble the information requested in Generic Letter 92-01, Revision N/A 1, Supplement 1 in accordance with the schedule developed by the BWRVIP.
PROCEDURE NUMBER 0.42 REVISION NUMBER 0 PAGE 10 OF 16
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