U-602421, Ro:On 950216,Div 2 125 Volt Dc Electrical Power Sys Declared Inoperable.Caused by Failure of Silicon Controlled Rectifier Firing Board in Div 2 Battery Charger.Battery Charger Repaired

Ro:On 950216,Div 2 125 Volt Dc Electrical Power Sys Declared Inoperable.Caused by Failure of Silicon Controlled Rectifier Firing Board in Div 2 Battery Charger.Battery Charger Repaired

ML20080K415
Person / Time
Site:	Clinton
Issue date:	02/22/1995
From:	Lyon M ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
U-602421, NUDOCS 9503010106
Download: ML20080K415 (2)

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tilinois Power Company Clinton Power Station P.O. Box 678 Clinton. IL 61727 Tel 217 935-8881 ILLIN4IS u-60242i PtpWER a50-95(o2 -22 xi 1N.150 EP640 February 22, 1995 Docket No. 50-461 10CFR50.47 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Clinton Power Station Notification Of Unusual Event

Dear Sir:

Please find attached a summary report of the "Notifcatic n of Unusual Event (NOUE)" which occurred at Clinton Power Station on February 16,1995. This summary report is submitted pursuant to Appendix 1 of NUREG-0654 (Revision 1) and Table 4-1 of the Clinton Power Station Emergency Plan. Ifyou have any questions concerning this summary report, please contact me.

Sincerely yours, Michael W. Lyon  ;

Director-Operations Training and Emergency Response WLY/mjb Attachment ec: Regional Administrator, Region III, USNRC J. McCormick-Barger, Chief Radiological Program Section I D. Pickett, NRC Clinton Licensing Project Manager NRC Resident Oflice Illinois Department of Nuclear Safety 9503010106 950222 I PDR ADOCK 05000461 S FDR h I

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, Attachment to U-602421  :

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- Clinton Power Station .

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Notification of Unusual Event j

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1 On Thursday, February 16,1995, at approximately 1315 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />5.003575e-4 months <br />, a Notification of  ;

Unusual Event (NOUE) was declared in accordance with Emergency Plan Implementing Procedure EC-02, EMERGENCY CLASSIFICATIONS. This procedure requires that a '  !

Notification of Unusual Event be declared for a loss of any engineered safety feature I

requiring plant shutdown by the Clinton Power Station (CPS) Technical Specifications (TS).

At approximately 0740 hours0.00856 days <br />0.206 hours <br />0.00122 weeks <br />2.8157e-4 months <br /> on F(bruary 16,1995 Clinton Power Station was  ;

operating at approximately 93% of rated thermal power when the Division 2125 Volt DC

• Electrical Power System was declared inoperable due to a failure of a silicon controlled rectifier firing board in the Division 2 battery charger. This resulted in entry into the Action S:atement for TS 3.8.4 which required the Division 2125-Volt DC Electrical Power System to be restored to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Per this TS, if the system was not restored to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, the plant was required to be in hot -

shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (i.e., by 2140 hours0.0248 days <br />0.594 hours <br />0.00354 weeks <br />8.1427e-4 months <br /> on February 16,1995). At 1315  ;

hours, the unit began a controlled shutdown to comply with TS 3.8.4. The Shift Supervisor then declared the NOUE. The State ofIllinois was notified at approximately i 1325 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.041625e-4 months <br />, and the NRC Incident Response Center was notified at approximately 1328 l hours.' l At approximately 1730 hours0.02 days <br />0.481 hours <br />0.00286 weeks <br />6.58265e-4 months <br />, CPS was informed of NRC Region III's intent to grant a Notice of Enforcement Discretion, allowing CPS to remain at a reduced power .

while repairs were completed. The battery charger was repaired and declared operable at approximately 1912 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.27516e-4 months <br />. The NOUE was also terminated at approximately 1912 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.27516e-4 months <br />.  ;

The State ofillinois was notified at approximately 1947 hours0.0225 days <br />0.541 hours <br />0.00322 weeks <br />7.408335e-4 months <br />, and the NRC Incident i Response Center was notified at approximately 1934 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.35887e-4 months <br />.

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