ML13322B099
| ML13322B099 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/21/1990 |
| From: | Nandy R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-65087, NUDOCS 9002280066 | |
| Download: ML13322B099 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 F. R. NANDY TELEPHONE MANAGER OF NUCLEAR LICENSING February 21, 1990 (714) 587-5400 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 TDI Diesel Crankshaft Oil Hole Cracking Problem (TAC No. 65087)
San Onofre Nuclear Generating Station Unit 1 This letter is provided in response to the NRC's November 21, 1989 safety evaluation of the TOI diesel crankshaft oil hole cracking problem at San Onofre Unit 1 which requested that SCE provide a submittal dealing with certain technical issues within 90 days. This response describes the actions that have been initiated by SCE in order to develop the requested information and the schedule for its submittal. In addition, information is provided regarding two other topics related to the emergency diesel generators.
The safety evaluation provides SCE with the option to either (1) replace the existing crankshafts with a superior design, or (2) demonstrate that SCE's eddy current inspection technique is adequate to detect 10 mils deep flaws with a high degree of confidence.
SCE has elected to pursue the second option.
Data collection and experimental work in the area of eddy current inspection capability requirements as well as work required to resolve the remaining technical issues identified in your letter has been initiated.
Based on the current schedule, SCE expects to provide its response to the safety evaluation by April 30, 1990. This response will include appropriate proposed amendments to the plant operating license.
The two additional topics which this letter addresses are: SCE's efforts to increase the 50 start-stop limit presently required by License Condition 3.L(1) between successive crankshaft inspections, and continuation of SCE's periodic reporting in response to 10 CFR 21 notifications received from the diesel manufacturer (TDI).
Diesel generator testing and analysis are under way to provide technical justification for increasing the aforementioned limit of 50 starts-stops to some higher number. It is expected that a request to revise License Condition 3.L(1) based on the results of the technical justification will be submitted for NRC rq0022 800/L..,i0 40
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-Document Control Desk February 21, 1990 approval during August 1990. This submittal date will not impact the schedule for the Cycle 11 refueling outage, based on the fact that the information that will be provided with this submittal is not required for restart from the outage.
For several years, SCE has been providing reports of actions taken or planned to be taken in response to 10 CFR 21 notifications from the diesel manufacturer.
This commitment originated in a NRC letter of June 17, 1985, which requested that the process of reporting continue pending issuance of the final safety evaluation. Now that a formal plant specific safety evaluation has been issued by the NRC, SCE believes that further reporting is not required and none is planned.
If you have any questions regarding this letter, please let me know.
Very truly yours, cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3