ML20141F642
| ML20141F642 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/18/1986 |
| From: | Reed C COMMONWEALTH EDISON CO. |
| To: | Taylor J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| 1567K, NUDOCS 8604230112 | |
| Download: ML20141F642 (6) | |
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', Commanwealth Edison j
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Chicago. Ilhnois 60690 April 18, 1986 Mr. James M. Taylor, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
LaSalle County Station Unit 2 Response to Notice of Violation and proposed Imposition of Civil penalty Inspection Report No. 50-374/85-034 NRC Docket No. 50-374
Reference:
J. G. Keppler letter to J. J. O'Connor dated March 19, 1986.
Dear Mr. Taylor:
This is Commonwealth Edison Company's (Edison) response to the above referenced Nuclear Regulatory Commission's (NRC) Notice of Violation, proposed Imposition of Civil penalties and accompanying inspection report.
We appreciate the opportunity to explain in detail Edison's program for addressing the matters at issue here.
Because Edison does not protest the fine, this letter is accompanied by a check as payment in full of the
$50,000.00 penalty.
Edison appreciates the significance of the deficiencies identified in the Notice. Our program to ensure the safe operation of our nuclear facilities depends on adequate and timely analysis of the effect of equipment outages on the status of ECCS systems. Edison acknowledges that the events which gave rise to these deficiencies were unacceptable. To ensure that similar incidents will not recur, Edison has initiated the corrective actions discussed below.
The attachment to this letter describes the wide range of measures, both immediate and long term, which have been instituted by the LaSalle County Nuclear power Station.
Immediate measures were taken to ensure that the violation was corrected and action was taken to institute a new procedure to prevent a recurrence of similar events. A significant, long term measure is the establishment of a task force which will analyze one specific Technical Specification system to develop more refined generic crit:ria for classifying equipment as either operable or inoperable. Upon conpletion of this task force effort, that criteria will be applied, where applicable, to other Technical Specifications.
86042.30117 860418
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Mr. J. M. Taylor April 18, 1986 These sneasures demonstrate Edison's continuing commitment to the operational safety of its nuclear stations. Edis.on believes that safety will be enhanced by the corrective actions described in this letter and its attachment and, therefore, that the LaSalle County Nuclear Power Station will continue to operate in a manner that fully ensures public health and safety.
Very truly yours, by L
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Cordell Reed Vice-President Im Attachment cc:
J. G. Keppler - Region III Region III Inspector - LSCS SUBSCRIpED AND Sh to before thip /g day j
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fu 1986 00th 1
' l otary Public' 156*1K
ATTAQ9ENT RESPONSE TO NOTICE OF VIOLATION VIOLATION j
On October
~7, 1985, with Unit 2 at 100% power, licensee personnel failed to properly evaluate ECCS operability after closing the low pressure coolant injection (LPCI) minimum flow valve to perform maintenance. Licensee l
personnel failed to realize that in closing the valve, Division 1 of ECCS I
should have been declared inoperable. Division 3, which consists of the high pressure core spray system (HPCS), had been declared inoperable since October 4, 1985 due to continued problems with the Unit 2B Diesel Generator cooling water pump breaker tripping. Once licensee personnel recognized the inoperable status of Division 1, they returned the minimum flow valve to l
service within one hour. However, by the time this division was restored to operable status, two divisions of ECCS had been inoperable for more than thirteen hours without action being initiated to either restore one of the inoperable divisions to an operable status or to meet the requirements of the applicable Technical Specification action statement.
ADMISSION OR DENIAL OF THE ALLEGED VIOLATION Commonwealth Edison admits the vitelation.
PEASON POR VIOLATION The cause for this violation was an inadequate evaluation of the effect of an inoperable minimum flow valve on the Low pressure Coolant Injection (LPCI) System. Shortly before this event, station management personnel had interpreted the Technical Specifications to permit operation of the plant with the minimum flow valve closed for seven days. This interpretation was based on an analysis of Technical Specification 3.3.3, Action 31, which prescribes action to be taken when the flow switch which controls the minimum flow valve is inoparabic. This specification requires
O that the inoperable switch be placed in the tripped condition within one a
hour, and restored to operable status within 7 days. Otherwise the associated LPCI System must be declared inoperable. Management personnel determined that the minimum flow valve should be placed in the closed position to ensure that sul.'ficient LPCI flow would be available to meet safety analysis requirements. This would ensure that in the event of a design basis accident, flow would not be diverted from the reactor vessel.
It was, in effect, a default decision:
the technical specification strongly implied that with the minimum flow valve inoperable, the LPCI System would still be operable, if the valve was in the proper position. Because it was believed that the system would not deliver sufficient flow with the valve open, it was determined that the system must be operable with the valve shut. This determination was made without adequate evaluation of the effect of no minimum flow on LPCC pump operability.
In particular, plant personnel I
failed to realize that the Technical Specifications ree sire the LPCI system to be considered inoperable whether the valve is trippec. either open or closed. We now know that this analysis was inadequate.
CORRECTIVE ACTION TAKEN AND RESULTS ACHIEVED 1
As soon as station management realized that the evaluation was in I
question, work was halted and the valve was returned to operable status.
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During this period (less than one hour), the LPCI A system was declared inoperable. Because the High Pressure Core Spray system (HPCS) was already l
inoperable, for unrelated reasons, Technical Specification 3.0.3 required a plant shutdown, if one of the inoperable ECCS systems was not restored to operable status within one hour. When LPCI 'A' was restored to operable status, specification 3.0.3 was exited.
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. CORRECTIVE ACTION TAKEN TO AVOID FURTHER NONCOMPLIANCE 1.
Conservative Operating Practices a.
Guidance has been issued to Shift Management and Operating Engineers prohibiting work on ECCS systems when a required redundant system is not operable. This restriction applies whether or not the planned work has any effect on system or component operability. Deviation l
from this restriction requires approval of the Production Superintendent.
b.
Shift personnel have been instructed to always declare the associated ECCS systems inoperable if the minimum flow valve or the associated flow switch is inoperable.
,e-2.
Training All licensed operators have been trained on this event, including the seriousness, potential consequences, and the above corrective actions.
3.
Technical Specifications a.
Action 31 of Technical Specification 3.3.3 does allow the minimum flow bypass switch to be inoperable and tripped for up to 7 days without declaring the associated system inoperable. While this action may be inappropriate in light of this event, a revision to the Technical Specifications is not proposed at this time. The same action is required by the BWH/5 Standard Technical Specifications (STS) and is presumed to be included in other BWR plant Technical Specifications. The BWR Owner's Group (BVROG) is presently proposing to revise the STS for all BVR product lines to provide appropriate basis for required actions, remove unnecessary requirements and improve the usability of the document (human factors consideration). This is a part of a major industry and NRC effort to consistently improve the Technical Specifications.
LaSalle County is actively participating in this effort and will submit proposed amendments as appropriate based on the results.
. i b.
A review was made of all Technical Specifications which required, as part of the action statements, tripping of an instrument or a logic channel, to determine if there were other specifications subject to misinterpretation. One additional item was identified, and an I
i interpretation / clarification has been issued to alert operating j
personnel to the ambiguity.
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4.
Guidance on operability
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a.
Additional guidance has been provided to operators as a part of a l
new station procedure, (LAP-220-4, Degraded Equipment Log), which l
requires the identification of items which must be considered when
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evaluating component operability and the effects of inoperable components or system operability.
In addition to providing this guidance, the procedure requires and provides the mechanism for obtaining assistance to adequately determine operability, b.
A task force'has been established to further develop criteria for determining when equipment is either operable or inoperable. This task force will analyze one technical specificaticn system thoroughly. This is expected to lead to a more refined set of generic criteria which can be applied by shift personnel to l
determine system operability when faced with component failure t
l within a system.
l DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED Full compliance with all regulatory requirements has been achieved.
The above mentioned task force on operability is expected to complete its evaluation by March 31, 1987.
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