ML13302B800
| ML13302B800 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/06/1990 |
| From: | Kokajko L Office of Nuclear Reactor Regulation |
| To: | Cotton G, Ray H San Diego Gas & Electric Co, Southern California Edison Co |
| References | |
| NUDOCS 9007120228 | |
| Download: ML13302B800 (3) | |
Text
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-UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 July 6, 1990 Docket Nos. 50-361 and 50-362 Mr. Harold B. Ray Mr. Gary D. Cotton Senior Vice President Senior Vice President Southern California Edison Co.
Engineering and Operations Irvine Operations Center San Diego Gas & Electric Co.
23 Parker Street 101 Ash Street Irvine, California 92718 San Diego, California 92112 Gentlemen:
SUBJECT:
GENERIC IMPLICATIONS AND RESOLUTION OF CEA FAILURE AT MAINE YANKEE On June 7, 1990, while conducting cold functional testing of the control element assemblies (CEAs) following the cycle 12 refueling outage at Maine Yankee, one CEA could not be fully inserted in the core. Subsequent inspection of the CEA revealed that the end cap was missing from the center CEA finger, the lower stainless steel spacer and boron carbide pellets had fallen out of the center finger and an axial crack existed at the lower end. The upper stainless steel spacer was cocked in the bottom of the CEA finger and was causing the center CEA finger to bind against the guide tube. The CEA could not be fully inserted in the core during cold functional testing due to interference from boron carbide pellets that had fallen into the center CEA guide tube.
On June 25, 1990, the NRC staff met with the Combustion Engineering Regulatory Response Group (CERRG) to discuss the generic implications and proposed resolution of the CEA failure that occurred at Maine Yankee. The CERRG concluded that the CEA failure was most likely due to irradiation assisted stress corrosion cracking (IASCC). The CERRG also concluded that the failure mechanism was only applicable to the older Combustion Engineering (CE) CEA design which did not have an absorber plug (other than boron carbide pellets) at the bottom of the center CEA finger. In order to resolve this issue, the CERRG proposed specific Action Programs for each affected licensee. The CERRG submitted its report to the NRC addressing this issue by letter dated June 26, 1990.
It is our understanding that San Onofre Nuclear Generating Station, Unit Nos. 2 and 3 currently do not have any of the old style CEAs installed in the reactor core and that you do not plan to use any old style CEAs in the future. Therefore, this problem is not applicable to San Onofre Nuclear Generating Station, Unit Nos. 2 and 3 and no specific actions are required. Please contact us if our understanding regarding this matter is not correct.
5-66).-K
Messrs. Ray and Cotton July 6, 1990 The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under Pub. L.96-511.
Sincerely,
/s/
Lawrence Kokajko, Project Manager Project Directorate V Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION
'Docket File NRC PDR Local PDR PD5 Reading D. Crutchfield MS 13A2 B. Boger MS 13E4 J. Larkins D. Foster L. Kokajko C. Holzle, OGC PD5 Plant File R. Zimmerman, RV J. Tatum L. Phillips R. Jones R. Hermann C. Cheng J. Partlow DRSP/PD5/L D5 DSP5 EMC D:PD5 DFoster f
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Messrs. Ray and Cotton San Onofre Nuclear Generating Southern California Edison Company Station, Unit Nos. 2 and 3 cc David R. Pigott Mr. Gary D. Cotton Orrick, Herrington & Sutcliffe Senior Vice President The Old Federal Reserve Bank Bldg.
Engineering and Operations 400 Sansome Street San Diego Gas & Electric Company San Francisco, California 94111
.101 Ash Street, P.O. Box 1831 San Diego, California 92112 Mr. Robert G. Lacy Manager, Nuclear San Diego Gas & Electric Company Mr. Charles B. Brinkman P. 0. Box 1831 Combustion Engineering, Inc.
San Diego, California 92112 12300 Twinbrook Parkway, Suite 300 Rockville, Maryland 20852 Resident Inspector/San Onofre NPS U.S. NRC Alan R. Watts, Esq.
P. 0. Box 4329 Rourke & Woodruff San Clemente, California 92672 701 S. Parker St. No. 7000 Orange, California 92668-4702 Mayor City of San Clemente Mr. Sherwin Harris San Clemente, California 92672 Resource Project Manager Public Utilities Department thairman City of Riverside Board of Supervisors 3900 Main Street County of San Diego Riverside California 92522 1600 Pacific Highway Room 335 San Diego, California 92101 Mr. Phil Johnson U.S. Nuclear Regulatory Commission Regional Administrator, Region V Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 1450 Maria Lane, Suite 210 Walnut Creek, California 94589 Walnut Creek, California 94596 Mr. Richard J. Kosiba, Project Manager Mr. John Hickman, Senior Health Bechtel Power Corporation Physicist 12440 E. Imperial Highway Environmental Radioactive Mgmt. Unit Norwalk, California 94596 Environmental Management Branch State Department of Health Services Charles R. Kocher, Esq.
714 P Street, Room 616 James A. Beoletto, Esq.
Sacramento, California 95814 Souther California Edison Company Irvine Operations Center Mr. Don Womeldorf 23 Parker Chief, Environmental Management Irvine, California 92718 California Department of Health 714 P Street, Room 616 Sacramento, California 95814