ML20247E135
| ML20247E135 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/21/1989 |
| From: | Baskin K SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8907260093 | |
| Download: ML20247E135 (7) | |
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v t. v Southern California Edison Company P.O BOX 800 2244 WALNUT GROVE AVENUE ROSEME AD, C ALirORNI A 9.7 70 KENNETH P. BASKIN T E L t pHomst j
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July 21, 1989 i
U. S. Nuclear Regulatory Commission
-Attention: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Docket Nos. 50-361 and 50-362 Reply to a Notice of Violation San Onofre Nuclear Generating Station Units 2 and 3
Reference:
Letter, Mr. B. L. Falkenberry (NRC) to Mr. Kenneth P. Baskin
-(SCE), dated June 22, 1989 The Reference forwarded NRC Inspection Report Nos. 50-361/88-35 and 50-362/88-37 and a Notice of Violation resulting from the special inspection conducted by Mr. F. R. Huey.
In accordance with 10 CFR 2.201, the enclosure to this' letter provides the Southern California Edison Company (SCE) reply to the Notice of Violation.
If you require any additional information, please do not hesitate to call me.
Very truly yours,
~
w Enclosure cc:
J. B. Martin, Regional Administrator, NRJ Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 gb(
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p ADoCK 05000362 PDC
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ENCLOSURE REPLY TO A NOTICE OF VIOLATION Appendix A to Mr. Falkenberry's letter, dated June 22, 1989, states in part:
A.
"10 CFR 50, Appendix B, Criterion XVI states that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective materials and equipment, and nonconformances are promptly identified and corrected.
" Contrary to the above requirement, the licensee determined on April 2,1988, that the freon level in emergency chiller ME-336 was low, as documented on deficiency tag #084348, and this condition was not properly evaluated and corrected until Mg 6,1988.
Failure to promptly correct this deficiency may have resulted in inoperability of emergency chiller ME-336.
"This is a Severity Level IV violation (Supplement I)."
RESPONSE TO ITEM A 1.
Reasons for the violation. if admitted.
SCE admits that on April 2, 1988, a deficiency tag was written on the low freon level in emergency chiller ME-336 and the condition was not corrected until May 6, 1988. As discussed further in the response to item B below, SCE did not realize that low freon level constituted a potentially nonconforming condition. As a result, between April 2 and April 22, 1988, the deficiency tag program was relied upon to replenish the freon level.
After the operability of the emergency chiller was questioned by the NRC on April 22, SCE admits that when the design basis could not be determined (indeterminate) a nonconformance report (NCR) was not prepared.
SCE admits that, in retrospect, the NCR program should have been invoked for this indeterminate and potentially nonconforming condition, rather than relying on engineering efforts to establish the design bases.
As discussed in the Response ',o a Notice of Violation, Mr. Kenneth P.
Baskin (SCE) to NRC, dated March 9,1989, it has been previously recognized that:
... some SCE personnel... have not fully understood the Site policy to issue an NCR whenever information exists that a condition may be nonconforming. As such, an NCR should be issued, with subsequent validation of the nonconforming
s condition performed in a time frame commensurate with the i
safety significance of the condition and existing plant l
conditions..."
In summary, SCE believes that the reasons for the failure to promptly evaluate and correct the low freon level were: (1) the programmatic failure to properly translate design information into operating procedures and instructions (a condition ci+ed ia item B below); and (2) personnel failure to understand and irrolement Site Policy, which
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required issuance of an NCR based on the April 22 NRC-identification i
of an indeterminate and potentially nonconforming condition (a deficiency which has been the subject of separate, previous NRC enforcement action).
2.
Corrective stens that have been taken and the results achieved.
1 As discussed in the Response to a Notice of Violation, Mr. Kenneth P.
Baskin (SCE) to NRC, dated March 9, 1989:
(a)
Appropriate SCE personnel have received additional instructions 1
on the prompt initiation of NCRs. As a result, subsequent to-this event, the threshold for issuance of NCRs has improved.
(b)
To ensure the uniform application of existing Site policy on when to initiate an NCR, a memorandum.from the Station Manager was issued on April 10, 1989, to reemphasize NCR requirements to appropriate Station personnel.
(c)
The procedure governing the prioritization of maintenance on the emergency chillers was revised to elevate the priority of future work associated with the emergency chillers.
3.
Corrective steos that will be taken to avoid further violations.
The aforementioned corrective steps taken as a result of the previous enforcement action (NRC Report 50-206/89-03) have been effective in ensuring timely identification, documentation and resolution of potentially nonconforming conditions.
4.
Date when full comoliance will be achieved.
Full compliance was achieved on May 6, 1988, when the emergency chiller freon level was restored.
Appendix A to Mr. Falkenberry's letter, dated June 22, 1989, states in part:
B.
"10 CFR 50, Appendix B, Criterion III states that measures shall be l
established to assure that the basis for those structures, systems, l
and components that prevent or mitigate the consequences of l
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' postulated accidents are correctly translated into specifications, drawings, procedures, and instructions.
" Contrary to the, above, the refrigerant (Freon) levels necessary.to i
assure operability of the Units 2 and 3 emergency chillers were not:
properly translated into precedures and instructions.
Prior to May 6,1988, the applicable procedure did not establish Freon level limits associated with the level in the sight glasses when the units were in the shutdown condition. Subsequent to May 6,1988, analyses performed by the licensee showed that, to assure operability of:the emergency chillers, the Freon level in the sight glass (with the unit shut down'.in excess _of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) should be greater than (1) 2 to 2 1/2 inches, as a function of _ con.ponent cooling-water. temperature, to ensure proper chiller unit operation, and (2). greater than 1.6 inches to provide the design basis 320 tons of cooling capacity.
"This is a-Severity Levei IV violation (Supplement 1)."
RESPONSE TO~ ITEM B 1,
Reasons for the violation. if admitteda SCE admits, as it acknowledged in the letter from Mr. Kenneth P.
Baskin (SCE) to Mr. John B. Martin (NRC), dated October 3,1988,' that SCE's control of design and engineering work has not' been adequate to achieve a high standard of engineering excellence.
Specifically, SCE admits that it failed in several instances, including the emergency chillers, to assure that the basis for those structures, systems, and components f hat prevent or mitigate the consequences of postulated accidents were correctly translated into specifications, drawings, procedures, and instructions.
Licensee Event Report (LER) No. 50-361/88-10, Revision 1, dated October 14., 1988, provides significant detall on the design and operation of the emergency chillers, the cause of the Event, and corrective actions. A brief summary of those facts and circumstances are as follows:
Facts and Circumstances The Emergency Chilled Water System (ECWS) serves to provide chilled water to remove heat from air conditioning cooling coils that are in service during emergency conditions. There are two independent ECWS trains that are common to Units 2 and 3.
Each of the ECWS trains is provided with a 100%
capacity emergency chiller. The chillers are normally in a standby condition, and start upon receipt of a signal from various safety systems.
If the chiller trips (e.g., low freon temperature), the chillers are reset locally, and vendor l
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.. instructions provide for manual adjustment of the load on the chiller, if necessary.
The chillers were initially charged and factory tested by the vendor for full rated heat removal capacity.
SCE purchased the chiller with a factory option of a freon level sight glass.
The sight glass is located on the cooler section near the cooling coils. The level of freon in the sight glass can be influenced by several factors 5 including whether the chiller has been recently operated and condensing water temperature f1cetuations.
Maintenance and operating procedurcs/ instructions for the chillers were based on vendor specifications. Although the chillers were initially charged at startup with the vendor's recommended charge (approximately 1745 pounds) of freon, operability limits and a correlation between the sight glass level and freon inventory were not provided by the vendor or the design organization.
SCE developed its own procedural guidance involving frecn level such that during chiller operation the freon level in the sight glass should be 1/2 inch. This 1/2 inch operating level is sufficient to ensure that the chiller cooling can satisfy the maximum design heat removal capability.
However, this guidance was not defined as operability criteria and, hence, not implemented as such.
On several previous occasions, a zero-level was observed in the sight glass.
Upon refilling, only approximately 500 lbs. of freon was necessary to restore the freon level.
Similarly from an operator's perspective, it was recognized that the chillers had been started and successfully operated with low freon levels.
After the NRC inspector questioned the operability of ME-336 on April 22, it was not until May 5 that guidance was issued on the minitrum freon level necessary for operability.
Although the question of the operability was being pursued, the interaction of key parameters and the design basis, and the vendor's inability to provide design information, slowed the resolution of this issue. Additionally, this issue was not raised to the appropriate level of management, resulting in its attempted resolution at the first line supervisory level.
3 Summary After initial startup testing, no guidance was provided on a f
minimum freon level (standby) to ensure the chillers are OPERABLE nor the minimum freon level during standby necessary 1
to provide the design basis cooling capacity.
I.
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l Therefore, this event was caused by a failure to adequately j
address the operational performance of tFe system design, ano 1
to identify such fundamental parameters as freon level and/or CCW temperature effects, which are required to ensure the operability of the system.
2.
Corrective steos that have been taken and the results achieved.
The Jctober 3,1988, letter from Mr. Baskin states in part:
... As was discussed in the June 10, 1988, SSFI exit meeting and in our responses to the Notices of Violation reMed to the SSFI and Unit 1 EQ, SCE committed to an exhaustive independent asse:,sment of technical support for the operation of SONGS...
... The Task Force concluded that the major contributors to the existing problems are the complexity of the current organization, heavy reliance on engineering contractors combined with inadequate allocation of SCE engineering resources, and the lack of readily accessible design basis documentation. As corrective actions to address these conclusions, the Task Force has recommended a reorganization with responsibility for design functions and the design basis focused in one department, the augmentation of in-house engineering resources and performance of all conceptual engineering _ in-house, and the establishment of a design basis documentation (DBD) program to recapture and maintain the design basis for all three units. SCE is committed to act on these recommendations to resolve the identified problems."
l As discussed in LER No. 50-361/88-10, Revision 1, dated October 14, 1988:
(a)
Operating guidelines for acceptable freon levels in the emergency chillers were established.
(b)
The design organization now recognizes that the communication of required operating and maintenance practices is an important element of the design control process. A portion of the DCP/PFC package now includes a section that explicitly defines such considerations as surveillance requirements and acceptance criteria, assumptions made with respect to design or operating practices, and assumptions made with respect to i
maintenance practices.
(c)
Procedure S023-0-9.1, " Critical Components Inspections",
established a program to perform a careful inspection of
" critical components" (selected components listed in the procedure) on a regular basis, in order to detect and correct trip hazards or water intrusion problems and to l
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I monitor and assess negative trends developing in the operating / standby parameters. An inspection sheet is provided containing appropriate information regarding operating / standby parameters (i.e., fluid levels,-
performance data, etc.) to guide thc operator on the inspection. This program should help to foster a questioning attitude among operators with regard to those-fundamental parameters necessary for system or component operability.-
3.
[orrective steps that will be taken to avoid further violations.
As short term corrective action, feedback from operators is being solicited. A joint review is being conducted of operator round
' sheets by operations and engineering personnel to determine if they
-capture important information about plant and equipment conditions.
Also, a questionnaire is. being-developed for operators to define the nature of their perceptions and observations of plant equipment and conditions.
4.
Date when full comoliance will be achieved.
Full compliance was. achieved on May 6, 1988, when appropriate design information was incorporated into the applicable operating procedures.
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