ML20087C322
| ML20087C322 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/01/1995 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9508090140 | |
| Download: ML20087C322 (3) | |
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southem caliknla Ediam Company
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August 1, 1995 j
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'I U. S. Nuclear Regulatory Commission
'l Document Control Desk i
Washington, D. C. 20555
Dear Sir:
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Subject:
Docket Nos. 50-361 and 50-362 Reply to a Notice of Violation j
San Onofre Nec'; r Generating Station, Units 2 and 3
References:
(A) 1,etter, Thomas P. Gwynn (NRC) to Harold B. Ray (Edison), dated i
June 30,1995 i
i (B) Letter, R.- M. Rosenblum (Edison) to Document Control Desk, dated j
June 13,1995.
1 Reference (A) provided the results of NRC Inspection Report (IR) 50-361/95-12 and i
50-362/95-12, conducted by Mr. M. Runyan and Ms. P. Goldberg March 6-10 and l
June 5-9, 1995. The enclosure to Reference (A) provided a proposed violation for failure to utilize San Onofre's corrective action program to address a problem that indicated a potential '
I common mode failure mechanism for motor-operated valves (MOV). This letter provides the -
i response to the proposed violation and requests that the proposed violation be withdrawn.
I On May 31,1995, during scheduled valve maintenance, MOV 3HV9300 failed to stroke.
Nonconformance Report (NCR) 95050087 was generated to address the potential for actuator degradation and provide an operability assessment. Examination of the actuator internals revealed -
3l water intnision, corrosion, and poor stem lubrication. 'At this time, the motor pinion gear was i
also found to have been installed in the reverse direction (a condition unrelated to the stroke failure).
i In an effort to evaluate the significance of the reversed motor pinion gear, the cognizant engineer reviewed Limitorque Part 21 notices and maintenance updates, recent site experience, and l
discussed the condition with other MOVATS engineers. The cognizant engineer did not generate a new NCR because he believed the incident was an isolated case based on these discussions and j
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reviews. His intention was to document this evaluation in the associated valve test package when l
the valve maintenance was completed.
Edison's corrective action program and policy is that either the existing NCR (95030185) should have been revised by the cognizant engineer to include a discussion of the reversed motor pinion gear, or a new NCR should have been issued for this item alone. No specific time frame is required for either of the two actions to be completed, but Edison expects this to be completed within a few days. The cognizant engineer did not meet Edison's expectations because the existing NCR still had not been revised or a new NCR issued by June 7,1995, a week later, when the NRC inspectors questioned the need for a formal, documented evaluation.
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When Edison management became aware that the reversed pinion gear had not been documented in an NCR, Edison management elected to issue a new NCR. NCR 95060029 was issued on June 8,1995; which is, therefore, the date when full compliance was achieved.
Edison management met on June 9,1995, and concluded that the root cause of the failure to either revise the existing NCR or issue a new NCR was another example of the same issue as that
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cited in NRC IR 95-02 to which Edison was in the process of responding [ Reference (B)].
Edison, therefore, broadened the corrective actions taken in response to the first citation to make l
them effective for both examples. As documented in our reply to the NRC IR 95-02 violation, Reference (B) states, in part:
"In addition, on June 9,1995, a second example of untimely NCR issuance was identified during an NRC inspection (Report No. 50-361 & 362/95-12). As a result of the June 9 finding, Edison has expanded the proposed NEDO [ Nuclear Engineering and Design Organization] and PE
[ Procurement Engineering] training on these procedure changes and the requirements for timely issuance of NCRs to include Station Technical, Maintenance, and Quality Control personnel."
On June 20,1995, Edison personnel briefed Messrs. M. Runyan and T. Scarborough, NRR, on the status of Edison's investigation, as follows:
(1) Edison pointed out that we had expanded the Reference (B) response scope to address this second example of untimely documentation. Reference (B) had been previously faxed to Mr. Runyan on June 16,1995.
(2) Subsequent inspection of similar valves determined that MOV 3HV9301 also had a reversed pinion gear, and further maintenance history reviews indicated two valves had been discovered in 1989 with reversed pinion gears. In total,39 of 44 additional similar valves had been inspected (no reversed pinion gears). [Since the June 20 briefing, one additional valve has been inspected and the gearing was found to be correctly configured.] The remaining four valves will be inspected during the Unit 3 outage which began on July 22,1995.
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(3) - Analyses of the reversed pinion condition for 3HV9300 and 3HV9301 concluded that -
sufficient engagement existed such that under all operating conditions, including design j
basis events, the valves were capable of operating successfully. A similar analysis of the valves not yet inspected yielded similar conclusions.
l (4) Records reviewed indicate that the subject valves appear to have been received from the -
1 manufacturer with the pinion gear reversed (manufacturing error). The manufacturer l
o was notified, and Edison has put this information on the INPO Nuclear Network for i
other utilities information.
(5) Edison has concluded there was no safety significance to the reversed pinion gear.
In summary, Edison believes the IR 95-12 pinion gear NCR issue is another example of the issue cited in IR 95-02. We explicitly addressed this second example in our reponse to that first l
citation. Accordingly, Edison respectfully requests that the NRC withdraw the duplicate violation-described in NRC IR 95-12.
l If you have any questions, or require additional information, please call me.
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Sincerely,
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L. J. Callan, Regional Administrator, NRC Region IV j
J. E. Dyer, Director, Division of Reactor Projects,. Region IV K. E. Perkins, Jr., Director, Walnut Creek Field Office, NRC Region IV l
J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 and 3 M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3
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