ML13317B227
| ML13317B227 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/29/1990 |
| From: | Nandy F SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13317B228 | List: |
| References | |
| NUDOCS 9012030052 | |
| Download: ML13317B227 (5) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 F. R. NANDY November 29, 1990 TELEPHONE MANAGER, NUCLEAR LICENSING (714) 454-4504 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Evaluation of the As Found Condition Thermal Shield Original Support System San Onofre Nuclear Generating Station Unit 1 The purpose of this letter is to provide the NRC with the Westinghouse evaluation of the as found condition of the thermal shield original support system. This information was requested by the NRC in a telephone discussion on October 26, 1990.
The enclosed evaluation of the as found condition provides Westinghouse's assessment of the lower reactor internals and vessel inspection data. This data consisted of five video tapes of SONGS 1 taken during the Summer, 1990.
The report concludes that the condition of the thermal shield and its supporting hardware closely resemble those predicted in Westinghouse WCAP-12148, dated February 1989. The report also concludes that the as found condition did not pose any undue risk to the health and safety of the public.
In addition to the Westinghouse evaluation, a root cause evaluation of the failure of the thermal shield support block fasteners is under way. Visual examination of the failed hidden bolts has been performed. However, determination of the fracture mode was hindered by the presence of high temperature oxidation on the surface of the material.
The retrieved lower 961:2031.*005-2 901129 F O R A 0. I<*~O 5
0 0
()
2 0 62~
P'DR AiDOCK 0)5C000206.
P PDC :
Document Control Desk
-2 block fasteners are being shipped to General Atomics laboratory for further analysis.
If you have any questions or comments, or if you would like additional information, please let me know.
Sincerely, Enclosure cc: J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 C. D. Townsend, NRC Resident Inpsector, San Onofre Unit 1
ENCLOSURE WESTINGHOUSE EVALUATION OF THE AS FOUND CONDITION
- 0 Westinghouse Energy Systems Nuclear and Advanced Electric Corporation Technolog Division Box 2728 Pittsburgh Pennsylvania 15230-2728 SCE-90-695 MED-RPV-3056 October 30, 1990 Mr. R. Ashe-Everest San Onofre Nuclear Generating Station Station Technical Division P.O. Box 128 San Clemente, CA 92674-0128 SOUTHERN CALIFORNIA EDISON SAN ONOFRE NUCLEAR GENERATING STATION UNIT 1 Review and Assessment of SONGS 1 Lower Reactor Internals and Vessel Inspection (Summer 1990)
Dear Mr. Ashe-Everest:
Please find attached a report providing a review and assessment of the lower reactor internals and vessel inspection data provided to Westinghouse. This data consisted of five video tapes taken during the summer, 1990 at SONGS 1.
If you have any questions, please contact Chuck Boyd at (412)-256-6343.
Sincerely, H. C. Calton, Manager 7
Western Region Domestic Customer Projects Department
/DRF Attachment cc: J. T. Reilly R. W. Waldo M. Motamed SONGS CDM Center
Copyright Notice The information transmitted herewith bears a Westinghouse copyright notice.
The NRC is permitted to make the number of copies of this information which are necessary for its internal use in connection with generic and plant-specific reviews and approvals as well as the issuance, denial, amendment, transfer, renewal, modification, suspension, revocation, or violation of a license, permit, order, or regulation subject to the requirements of 10 CFR 2.790 regarding restrictions on public disclosure to the extent such information has been identified as proprietary by Westinghouse, copyright protection not withstanding. With respect to the non-proprietary versions of this information, the NRC is permitted to make the number of copies beyond those.
necessary for its internal use which are necessary in order to have one copy available for public viewing in the appropriate docket files in the public document room in Washington, DC and in local public document rooms as may be required by NRC regulations if the number of copies submitted is insufficient for this purpose. The NRC is not authorized to make copies for the personal use of members of the public who make use of the NRC public document rooms.
Copies made by the NRC must include the copyright notice in all instances and the proprietary notice if the original was identified as proprietary.