ML20006B081
| ML20006B081 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/25/1990 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9001310380 | |
| Download: ML20006B081 (6) | |
Text
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i Southem Calihmin Edison Company 23 PARMER STRECT
- Rveht, CALirORNIA 92718
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MANOLD B. RAY tettpwoht January 25, 1990
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l U. S. Nuclear Regulatory Commission I
Attention: Document Control Desk Washington, D.C.
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Gentlemen:
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Subject:
Docket No. 50-206 Reply to a Notice of Violation San onofre Nuclear Generatina station. Unit 1 Reference Letter, Mr.
B. H. Faulkenberry (NRC) to Mr. Harold B.
1 Ray (SCE), dated December 26, 1989 In accordance with 10CFR2.201, the enclosure to this letter i
provides the Southern California Edison (SCE) reply to a Notice of Violation which was issued by the referenced letter.
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The referenced letter also forwarded NRC Inspection Report i
No. 50-206/89-31.
This inspection report identified five significant deficiencies related to SCE's program for handling corrective actions.
Since they cannot all be addressed adequately in response to the Notice of Violation, we will discuss them in a separate letter which will be issued shortly.
If you require any additional information, please let ne know.
Sincerely, d
Enclosure cc:
J. B. Martin, Regional Administrator, Region V
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C. W. Caldwell, Senior Resident Inspector, San Onofre i
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ENCLOSURE REPLY TO A NOTICE OF VIOLATION Appendix A to Mr. Faulkenberry's letter dated December 26, 1989 states in part:
"A.
10CFR50, Appendix B, Criterion XVI, ' Corrective Actions,' as implemented by Chapter 1-F of the Southern California Edison Topical Quality Assurance Manual statest
' Measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected.
In cases of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.
The identification of the significant condition adverse to quality, the cause of the condition, and corrective action taken shall be documented and reported to appropriate levels of management.'
' Contrary to the above, the licensee's program did not assure that adequate corrective actions were taken to prevent additional failures of Automatic switch Company (ASCO) solenoid valves after it was identified in Licensee Event Report (LER)87-016 (dated December 12, 1987) that the presence of a thin hard film formed between the top of the slug and the slug housing was the cause for five solenoid valve failures in 1987.
On March 11, 1988, ASCO informed the licensee that a thin coat of Dow Corning 550 lubricant was applied to the valves, and cognizant licensee personnel at the time recognized this lubricant to be the cause of the 1987 failures.
Notwithstanding the knowledge within the licensee's organization of the root cause of the failures, "1.
The Nuclear Engineering & Construction (Projects) group installed new ASCO solenoid valves for CV-304 and CV-305 in April 1988, unaware that previous failures of similar ASCO valves had been experienced; "2.
On August 23, 1989, CV-304, in the normal charging line to reactor coolant system Loop A, failed to close due to the use of Dow Corning 550 lubricant on the associated ASCO solenoid valve; "3.
The ASCO solenoid valves models of concern were not added to the licensee's Control of Problem Equipment (COPE) List until September 1, 1989, following the August 23, 1989 failure of CV-304."
e Reply to a Notice of Violation January 25, 1990 RESPONSE TO ITEM A 1.
Reasons for the violation, if admitted.
As discussed in NRC Inspection Report No. 50-206/89-31 and indicated in Item A above, CV-304 failed because its solenoid valve had been installed without SCE first taking action to remove the lubricant which had been identified as the probable cause of prior failures.
If the scienoid valve had been included on the control of Problem Equipment (COPE) List prior to its installation in the plant, then appropriate action to prevent its failure should have taken place, consistent with existing, installed valves of the same type.
The solenoid valve was not included on the COPE List prior to September 1, 1989 primarily because systematic requirements and procedures for input to the list from various-sources (e.g.,
the NCR disposition program) were not considered necessary and had not been established initially.
Rather, it was judged that the need to include equipment on the COPE List would be recognized, and appropriate action taken, without the need for such requirements and procedures.
In the case of CV-304, as summarized in the NRC Inspection Report, the determination of the cause of solenoid valve failures involved a number of transactions over a considerable period, and a formal conclusion concerning root cause had not yet been documented and approved by Station Technical prior to its failure.
During what became a protracted period of attempting to obtain concurrence from the vendor as to the failure cause, corrective action had been implemented with respect to existing, installed components.
However, no actica was taken to address the newly installed components by including the solenoids on the COPE List.
2.
Corrective steps that have been taken and the results achieved.
On August 25, 1989 the failed solenoid valve for CV-304 was replaced with an in-kind valve for which the offending lubricant had been removed, as for similar other installed valves.
Solenoid valves which might be subject to this failure mechanism were included on the COPE List on September 1.
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Reply to Notice of Violation January 25, 1990 The failed solenoid was analyzed to determine the nature of the thin, hard film between the solenoid slug and housing which j
had caused the failure.
The analysis, which was completed by an i
I independent laboratory on December 18, 1989, concluded that the film was a residue of Dow Corning 550 lubricant.
As a consequence of our review of the procedure used'to maintain the solenoid valves, Maintenance Procedure SO1-I-8.171,
" Valves - ASCO Models 206-380, 206-381 Solenoid Valve Overhaul",
was revised on September 11, 1989 to include additional cautions i
to ensure that Dow Corning 550 used on gasket parts does not come into contact with valve body components.
3.
Corrective steps that will be taken to avoid further i
violations.
l Procedure SO123-XV-5, " Nonconforming Material, Parts or j
Components," will be revised by April 16, 1990 to incorporate the i
1 requirement for the COPE Program to be considered twice during the NCR process.
The first will be during the disposition phase and the second during the root-cause evaluation phase.
- Also, instructions concerning how to provide input to COPE will be included in the procedure.
Appropriate engineering personnel involved in the origination and processing of NCRs will receive training on input from the NCR Program to the COPE Program by June 1, 1990.
4.
Date when full compliance will be achieved.
i Full compliance was achieved on August 25, 1989 when CV-304 3
was returned to operable status.
Appendix A to Mr. Paulkenberry's letter dated December 26, 1989 also states in part:
"B.
Section 3.0.3 of the Unit 1 Technical Specifications (TS) for the safety injection and containment spray systems states that the reactor shall not be maintained critical unless a number of conditions are met.
These Limiting Conditions for Operation (LCOs) include the operability of recirculation pumps, the recirculation heat exchanger, two charging pumps, and valves and interlocks associated with those systems.
With inoperable associated valves for this TS, Section 3.0.3 of the TS applies.
"Section 3.0.3 of the TS specifies that, when an LCO is not met, action shall be initiated within one hour to place the Unit in a Mode in which the specification does not apply by placing it in at least hot standby within the next six hours and in at least hot shutdown within the following six hours.
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l Reply to a Notice of Violation January 25, 1990
" Contrary to the above, on August 23, 1989, with Unit 1 operating in Mode 1, the licensee did not initiate action within one hour to shut down the Unit after it was determined at 3:22 p.m. that LCO 3.3.1 was not satisfied.
Specifically, charging isolation valve CV-304, a valve which must close to ensure acceptable post-LOCA, safety injection system operation, was inoperable."
RESPONSE TO ITEM B 1.
Reasons for the violation, if_ admitted.
In reviewing the Technical Specifications at the time of the failure, Edison concluded that, since Hot Leg Recirculation (HLR) was not explicitly included in the Technical Specifications, a 72-hour action statement would be applied, such that shutdown of the unit would be required if CV-304 was not returned to operable status within that period.
This 72-hour period is consistent with Technical Specification requirements for Safety Injection System train outages on San Onofre Units 2 and 3 and for the Emergency Diesel Generator outages on Unit 1.
Accordingly, it was considered reasonable at the time.
However, as discussed in the NRC Inspection Report, this conclusion did not take into consideration the EQ status of the HLR flowpaths.
Also, as discussed in the November 16, 1989 letter from Mr. H.
B. Ray (SCE) to Mr. R.
Zimmerman (NRC), it did not reflect a conservative implementation of the Technical Specifications.
2.
Corrective steps that have been taken and the results achieved.
The circumstances of this occurrence were reviewed with appropriate management personnel, and SCE's commitment to conservatively implement the Technical Specifications was reemphasized.
Also, the need for wide review of Technical Specification interpretation and for discussion with NRC staff when the application or interpretation is not sufficiently clear was discussed.
3.
Corrective steps that will be taken to avoid further violations.
SCE will submit a proposed change to the Technical Specifications by April 30, 1990 to explicitly address recirculation system operability, including appropriate-limiting conditions for operation and action statements.
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Reply to a Notice of Violation January 25, 1990 4.
Date when full compliance will be achieved.
Full compliance was achieved on August 25, 1989 when CV-304 was restored to operable status and Technical Specification 3.0.3 was exited.