ML20196A497
| ML20196A497 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 11/23/1998 |
| From: | Hannon J NRC (Affiliation Not Assigned) |
| To: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| Shared Package | |
| ML20196A502 | List: |
| References | |
| TAC-MA3891, NUDOCS 9811300018 | |
| Download: ML20196A497 (3) | |
Text
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' Mr. G. R. H::m
. November 23, 1998 Sr. Vice Prrsident of En:rgy Supply N br ska Public Power District 141415th Street -
Columbus, NE 68601
SUBJECT:
FLAW EVALUATION OF MAIN STEAM NOZZLE TO SHELL WELD: COOPER NUCLEAR STATION (TAC NO. MA3891)
Dear Mr. Horn:
By letter dated November 17,'1998, Nebraska Public Power District submitted a fracture mechanics evaluation related to a flaw indication found in the main steam nozzle to shell weld NVE-BD-N3A at the Cooper Nuclear Station (CNS). The flaw indication is believed to be a fabrication defect, probably due to a slag inclusion formed during welding. The size of the indication exceeded the acceptance criteria of ASME Code Section XI, IWB-3512-1 and required further fracture mechanics evaluation.
.We have completed the review of your fracture mechanics evaluation which provides reasonable assurance that the structuralintegrity of the subject nozzle weld can be maintained.
We therefore, conclude that the CNS can be safely operated for at least one fuel cycle (Cycle
- 19) with the indication in as-is condition. However, for continued operation beyond the next fuel cycle, our approval will be contingent upon reinspection or repair of the subject weld in accordance with the Code requirements.
..Our safety evaluation is enclosed. If you have any questions on this matter, please call David 1Wigginton, (301) 415-1301.
Sincerely, ORIGINAL SIGNED BY:
4 John N. Hannon, Director Project Directorate IV-1 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation 4
Docket No. 50-298
Enclosure:
As stated' 1
cc w/ encl: See next page fD.
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~ WASHINGTON, D.C. 30006 4001 Ilovember 23, 1998 Mr. G. R. Horn Sr. Vice President of Energy Supply Nebraska Public Power District 141415th Street Columbus, NE 68601 -
i
SUBJECT:
FLAW EVALUATION OF MAIN STEAM NOZZLE TO SHELL WELD: COOPER NUCLEAR STATION (TAC NO. MA3891)
Dear Mr. Horn:
By letter dated November 17,1998, Nebraska Public Power District submitted a fracture mechanics evaluation related to a flaw indication found in the main steam nozzle to shell weld
- NVE-BD-N3A at the Cooper Nuclear Station (CNS). The flaw indication is believed to be a fabrication defect, probably due to a slag inclusion formed during welding. The size of the
- indication exceeded the acceptance criteria of ASME Code Section XI, IWB-3512-1 and required further fracture mechanics evaluation.
We have completed the review of your fracture mechanics evaluation which provides reasonable assurance that the structuralintegrity of the subject nozzle weld can be maintained.
We therefore, conclude that the CNS can be safely operated for at least one fuel cycle (Cycle
- 19) with the indication in as-is condition. However, for continued operation beyond the next fuel cycle, our approval will be contingent upon reinspection or repair of the subject weld in
= accordance with the Code requirements.
Our safety evaluation is enclosed, if you have any questions on this matter, please call David Wigginton, (301) 415-1301.
Sincerely, John N. Hannon, Director Project Directorate IV-1 Division of Reactor Projects Ill/IV Office of Nuclear Reactor Regulation Docket No. 50-298
Enclosure:
As stated cc w/ encl: See next page 2
.~.
' Mr.' G. R. Hom.
Nebraska Public Power District Coope NuclearStation cc:
Mr. John R McPhail, General Counsel Lincoln Electric System -
' Nebraska Public Power District ATTN: Mr. Ron Otoddard P. O. Box 499 1040 0 Street 4
Columbus, NE 68602-0499 Box 80869 i
Lincoln, NG 68501 Nebraska Public Power District' ATTN: Mr. J. ' H. Swailes MidAmerican Energy Vice President of Nuclear Energy
' ATTN: Dr. William D. Leech, Manager-Nuclear:
P. O. Box 98 907 Walnut Street
' Brownville, NE 68321 P. O. Box 657 4
Des Moines, IA 50303-0657 Randolph Wood, Director 1
Nebraska Department of Environmental Nebraska Public Power District j.
Control ATTN: Mr. B. L. Houston, Nuclear i
_ P. O. Box 98922-Licensing & Safety Manager -
Lincoln, NE 68509-8922 P. O. Box 98 Brownville, NE 68321 Mr. Larry Bohlken, Chairman 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 Brownville, NE 68321 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suita 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
' 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-
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