ML20206F174
| ML20206F174 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/27/1999 |
| From: | Dyer J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Mcelwain J ILLINOIS POWER CO. |
| References | |
| CAL-III-97-09, CAL-III-97-9, NUDOCS 9905060019 | |
| Download: ML20206F174 (4) | |
Text
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. #A Mag'o NUCLEAR REGULATORY COMMISSION
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REGION 118 o
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801 WARRENVILLE ROAD e
LISLE. ILUNOIS 60532-4351 ty p'
April 27; 1999 Mr. John P. McElwain Chief Nuclear Officer Clinton Power Station Illinois Power Company Mail Code V-275 P. O. Box 678 Clinton,IL 61727-
SUBJECT:
CLOSURE OF CONFIRMATORY ACTION LETTER 50-461/Rlll-97-009
Dear Mr. McElwain:
This letter is to inform you that the NRC has completed its review of the actions taken by filinois Power (lP) as specified in NRC Confirmatory Action Letter (CAL) 50-461/ Rill-97-009 issued on August 6,1997, The CAL was prompted by the July 22,1997, failure of one safety-related and one nonsafety-related Westinghouse 4160 volt,1200 amp breaker and the August 5,1997, failure of a similar safety-related circuit breaker. The CAL dealt specifically with the issues stemming from the failure of IP to provide reasonable assurance that safety-related circuit breakers would function when called upon.
The CAL documented the NRC's understanding that IP would preserve the breaker that failed to open on August 5 in its'as4 ailed position to allow an independent investigation team, under the
- observance of an NRC Augmented Inspection Team (AIT), to establish the failure mechanism for the breaker failure, and would take effective corrective action to prevent recurrence. In '
addition, IP would establish a basis for reasonable assurance that all safety-related breakers will function when called upon ' The CAL also documented the understanding that IP would document in a letter to the NRC, the failure mechanism of the breakers, the corrective actions taken to prevent recurrence, and the basis for reasonable assurance that all safety-related breakers will function when called upon, and that IP would meet with the NRC to discuss these determinations prior to restarting Clinton Power Station (CPS).
lilinois Power provided an interim response to the CAL on November 13,1997.- In this response, IP discussed the establishment of a Special investigation Team (SIT) to determine the root cause of the July 22 and August 5 breaker failures. The SIT determined, under the observation of the AIT, that the circuit breaker failures were due to excessive friction forces in the upper operating mechanism of the circuit breakers.' This friction force exceeded the capabilities of the springs that were specifically designed to open the circuit breaker. The SIT further determined that a major contributing factor to the circuit breaker failures was deficiencies in the preventive maintenance program.
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l J. McElwain l l
In the final response to the CAL, dated December 11,1998, IP reconfirmed the breaker failure i
mechanism described in the interim response. In addition, IP management stated that based on the completed circuit breaker refurbishment and maintenance activities, the changes to the preventive maintenance program, and the activities that will be completed prior to restart from the current outage, reasonable assurance had been established that safety-related breakers would function when called upon.
lilinois Power management met with the NRC Manual Chapter 0350 Panel to discuss the root causes of the breaker failures and corrective actions accomplished or planned to prevent recurrence during the course of several public meetings. At the December 1998 meeting, which was conducted to fulfill the commitment documented in the CAL to discuss the breaker failure mechanisms and corrective actions taken prior to restart, IP committed to refurbish or replace all Division I safety-related 4160 volt,1200 amp circuit breakers prior to plant restart and to refurbish or replace all similar Division ll breakers by September 30,1999. In addition, IP committed to conduct a special interim maintenance activity for those Division 11 breakers that will not be completely refurbished or replaced prior to restart. The procedure for this special interim maintenance activity provided instructions for removing excess friction forces in the upper mechanism and conducting preventive maintenance on the circuit breakers.
The NRC conducted a team inspection, the Safety System Engineering Inspection (SSEl),
during February and March 1999 to review engineering / design issues including the resolution of the circuit breaker concerns. The SSEI team verified that the information provided in IPs written responses and during the public meetings was accurate. In addition, the team observed a high level of IP management involvement in the breaker program which resulted in significant improvement in maintenance and testing of circuit breakers. Further, the CPS staff exhibited a thorough knowledge of breaker design, maintenance, and testing requirements; demonstrated improved work practices during breaker maintenance activities; and exhibited good teamwork and adherence to procedure requirements. The team concluded that IP's planned and completed corrective actions established a basis for reasonable assurance that all safety-related breakers will function when called upon. The team's conclusions and findings are documented in NRC Inspection Report 50-461/99003 which was issued on April 21,1999.
The NRC considers IP's actions associated with CAL Rill-97-009 to be satisfactory, and therefore, the CAL conceming the August 5,1997, Westinghouse circuit breaker failure at CPS is considered closed. The inspection and evaluation activities outlined in the revised MC 0350 Restart Action Plan, issued on July 14,1998, are currently under final review. Once this review is complete, a separate letter documenting the closure of the Action Plan will be forwarded to you.
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J. McElwain
-S-if you have any questions regarding the information in this letter, please contact me or Thomas Kozak at 630/829-9657 or 630/829-9866, respectively.
Sincerely,
/s/ J. E. Dyer James E. Dyer Regional Administrator Docket No. 50-461 License No. NPF-62 cc:
G. Hunger, Station Manager R. Phares, Manager, Nuclear Safety and Performance improvement J. Sipek, Director - Licensing M. Aguilar, Assistant Attomey General G. Stramback, Regulatory Licensing Services Project Manager General Electric Company Chairman, DeWitt County Board State Liaison Officer Chairman, Illinois Commerce Commission Distnbution:
RPC (E-Mail)
Project Mgr., NRR J. Caldwell, Rlli B. Clayton, Rlli SRI Clinton DRP DRS RlliPRR PUBLIC IE-0[ gM Docket File l
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DOCUMENT NAME: G:\\ CLIN \\CALO9-CL.WPD
- See previous concurrences To receive a co y of this document, indicate in the box "C" = Copy w/o att/end "E" = Copy w/sttlencl "N" = No copy OFFICE
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- Rill lN NRR lg Rlli g Rlli l
NAME Kozak:co Gardner Richards-fff' gp/ Depas M )-
Dyer O!/k DATE 04/20/99 04/20/99 04/6 v.@04&//69' 04/21/99 OFFICIAL RECO I
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l J. McElwain If you have any questions regarding the information in this letter, please contact me or Thomas Kozak at 630/829-9657 or 630/829-9866, respectively.
Sincerely, James E. Dyer Regional Administrator Docket No. 50461 License No. NPF-62 cc:
G. Hunger, Station Manager R. Phares, Manager, Nuclear Safety and Performance improvement J. Sipek, Director-Licensing M. Aguilar. Assistant Attorney General G. Stramback, Regulatory Licensing Services Project Manager General Electric Company Chairman, DeWitt County Board State Liaison Officer Chairman, Illinois Commerce Commission Distribution:
RPC (E-Mail)
Project Mgr., NRR J. Caldwell, Rlli B. Clayton, Rlli SRI Clinton DRP DRS Rlli PRR PUBLIC IE-01 Docket File l
GREENS l
l DOCUMENT NAME: G:\\ CLIN \\CALO9-CL.WPD To receive a co >y of this document, indicate in the box "C" = Copy w/o att/enci"E" = Copy w/att/enci"N" = No copy OFFICE Rlll 6, Rill ld NRR Rill l
Rlli l
NAME Kozak:co dSardner b Richards Dapas Dyer DATE 04P)#99 04W/99 04/ /99 04/ /99 04/ /99 OFFICIAL RECORD COPY l