ML20078M188
| ML20078M188 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 02/07/1995 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-92-01, GL-92-1, NLS950048, NUDOCS 9502130268 | |
| Download: ML20078M188 (7) | |
Text
.
GENERAL OFFICE Hs Nebraska Public Power District P o. Box 499, COLUMBUS, NEBRASKA 68602-0499
- T"S"AIE'%'"
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GUY R. llORN Vice-President, Nuclear (402) 563-5518 NLS950048 February 7,1995 i
U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Response to Request For Additional Information Generic Letter 92-01, Revision 1 Cooper Nuclear Station, NRC Docket 50-298, DPR-46
Reference:
1)
Letter from James R. Hall (NRC) to G. R. Horn, NPPD, dated January 9,1995, " Generic Letter (GL) 92-01, Revision 1, Reactor Vessel Structural Integrity" 2)
Letter from G. R. Horn (NPPD) to USNRC dated July 1,1992,
" Response to Generic Letter 92-01, Revision 1" 3)
Letter from G. R. Horn (NPPD) to USNRC dated July 2,1993, t
" Response to Request for Additional Information Generic Letter 92-01 Revision 1" 4)
Letter from G. R. Horn (NPPD) to USNRC dated September 16,1993,
" Provision of Additional Information, Generic Letter 92-01, Revision 1" i
The Nebraska Public Power District (District) hertiby provides the response to the NRC's request for additional information (Reference 1) concerning the District's previous responses to Generic Letter 92-01, Revision 1 (References 2,3, and 4).
Generic Letter 92-01, Revision 1 requested that the District provide information to demonstrate compliance with NRC regulations concerning reactor vessel fracture toughness requirements and vessel material surveillance programs.
In the previous responses (References 2,3, and 4) associated with this issue, the District provided detailed discussions on the bases for its compliance with these NRC requirements.
l The attached discussion supplements the previous submittals and responds to the questions raised in the NRC's letter (Reference 1.)
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NLS950048 February 7,,1995-j
'Page,Q If you have any questions or need additional information, please contact me.
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' NLS950048 February 7,1995 Attachment ATTACHMENT 1.
QUESTION The initial RTu, values determined by GE's initial methodology have not been validated and the BWR Owner's Group report, GE-NE-523-109-0893, entitled, " Basis For GE RT, Estimation Method," did not resolve the issue. GE is in the process of validating its methodology for resolving the initial RT, determination issue and will document the results in a topical report. The BWR Owner's Group is obtaining approval from its members to provide the GE topical report to the NRC staff for its review and approval. We request that you submit within 30 days a commitment to the BWR Owner's Group effort or a schedule for a plant-specific analysis to resolve this issue.
DISTRICT RESPONSE The District is a participant of the BWR Owner's Group (BWROG) and is committed to the BWROG's current effort to validate the RTy, values determined by GE's initial methodology.
2.
OUESTION Provide confirmation of the plant-specific applicability of topical report, NEDO-32205, Revision 1,(as specified in Appendix B of that report).
DISTRICT RESPONSE The District filled out the applicability review forms that were a part of the original version of NEDO-32205 and enclosed them as Appendix A to Reference 3 for CNS.
The information provided in these forms demonstrated that the beltline plates and welds at CNS are enveloped by the Topical Report analysis and therefore meet the requirements for demonstrating equivalent margin as allowed by 10CFR50 Appendix G.
Subsequent to the District's submittal of Reference 3, the topical report was re-issued as NEDO-32205-A, Revision 1.
To verify that the beltline materials at CNS are enveloped by the analysis in this revised topical report the applicability review forms from revision 1 of NEDO-32205-A have been completed and are included as Appendix A to this letter.
3.
QUESTION Submit a request for approval of the topical report (NEDO-32205-A, Revision 1) as the basis for demonstrating compliance with 10 CFR Part 50, Appendix G, Paragraph IV.A.1.
Page 1
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NLS950048 February 7,1995
' Attachment :
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- ' DISTRICT RERPONSE The District requests that the NRC approve NEDO-32205-A, Revision 1, "10CFR50 Appendix G Equivalent Margin Analysis For Low Upper Shelf Energy In BWR/2 Through BWR/6 Vessels" as the basis by which the District demonstrates compliance with 10CFR50, Appendix G, Paragraph IV.A.1 for CNS.
' 4.
QUESTION Verify that the information you have provided for your facility has been accurately entered in the data base DISTRICT RESPONSE The District has reviewed the information entered in the data tables in enclosures 1 and 2 of Reference 1 and has found the information to be accurate.
Page 2
NEDO-32205-A EQUIVALENT MARGIN ANALYSIS PLANT APPLICABILITY VERIFICATION FORM
?
FOR CAOPER NUCLEAR STATION BWR/3-6 PLATE Surveillance Plate USE:
%Cu =
0.21%
(5-5) 1 Capsule Fluence =
2.4 x 10 (5-5)
Measured % Decrease =
6%
(Charpy Curves) (5-9)
R.G. 1.99 Predicted % Decrease =
12.5%
(R.G. 1.99, Figure 2)
_1 (5-9) i limitino Beltline Plate USE:
%Cu =
0.21%
(7-15) l 32 EFPY Fluence =
1.1 x 10*8 (7-15) i l
R.G. 1.99 Predicted % Decrease =
18%
(R.G.1.99, Figure 2) (7-15) 1 Adjusted % Decrease =
N/A (R.G. 1.99, Position 2.2) 18 % 121%, so vessel plates are bounded by equivalent margin analysis NOTE: The reference numbers in parentheses are the page numbers from GE Report No. GE-NE-523-159-1292 dated February 1993,
" Cooper Nuclear Station Vessel Surveillance Materials Testing and Fracture Toughness Analysis," transmitted to i
NRC by letter dated February 25, 1993.
NEDO-32205-A EQUIVALENT NARGIN ANALYSIS PLANT APPLICABILITY VERIFICATION FORM FOR COOPER NUCLEAR STATION BE L2-6 WELD Surveillance Weld USE:
%Cu =
0.23%
(5-5)
Capsule Fluence =
2.4 x 10" (5-5)
Measured % Decrease =
22%
(Charpy Curves)
(5-9)
R.G. 1.99 Predicted % Decrease =
15.5%
(R.G. 1.99, Figure 2)
(5-9)
)
Limitina Beltline Weld USE:
%Cu =
0.19%
(7-15) 18 1
32 EFPY Fluence =
1.1 x 10 (7-15) l 1
20%
R.G. 1.99. Predicted % Decrease =
(R.G. 1.99, Figure 2)
(7-20)
Adjusted % Decrease = 30.5%
(R.G.1.99, Position 2.2) f (7-15) l 30.5 % $ 34%, so vessel welds are bounded by equivalent margin analysis
)
)
l LIST OF NRC COMMITMENTS l ATTACHMENT 3 l
Correspondence No: NLS950048 j
l 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 is committed to the BWROG's currer.it ef fort to validate the RTm values deter 2nined by GE's initial None
- methodology.
l l
PROCEDURE NUMBER 0.42 l
REVISION NUMBER 0 l
PAGE 10 OF 16 l