ML19269C722

Forwards LER 79-008/03L-0

ML19269C722
Person / Time
Site:	Davis Besse
Issue date:	02/05/1979
From:	Murray T TOLEDO EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19269C723	List: ML19269C722 ML19269C728
References
L79-135, NUDOCS 7902120128
Download: ML19269C722 (1)

Text

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TOLEDO CE2 EDISON February 5, 1979 L79-135 FILE: RR 2 (NP-33-79-08)

Docket No. 50-346 License No. NPF-3 Mr. James G. Keppler Regional Director, Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

Reportable Occurrence 79-008 Davis-Besse Nuclear Power Station Unit 1 Date of Occurrence: January 9, 1979 Enclosed are three copies of Licensee Event Report 79-008 with a supplemental information sheet which is being submitted in accordance with Technical Speci-fication 6.9 to provide 30 day wricten notification of the subject occurrence.

Yours truly, fasy,. 0 k<*ylfm Terry D. Murray Station Superintendent Davis-Besse Nuclear Power Station TDM/SNB/lj k Enclosure cc: Dr. Ernst Volgenau, Director Office of Inspection and Enforcement Enc 1: 30 copies LER 79-008 Mr. William G. Mcdonald, Director Office of Management Information and Program Control Encl: 3 copies LER 79-008

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• TOLEDO EDISON COSTANY DAVIS-BESSE NUCLEAR POWER $2ATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER MP-33-79-08 i

DATE OF EVENT: January 9,1979  ;

FACILITY: Davi'-Besse Unit 1 IDENTIFICATION OF OCCURRENCE:

Containment Recirculation System Fan 1-1 failed to run Conditions Prior to Occurrence: The unit was in Mode 1, with Power (MUT) = 2732, and Load (Gross MUE) = 910 Description of Occurrence: On January 9,1979 during the performance of Surveillance Test ST 5065.06, " Containment Recirculation System Monthly Test", Containment Recir-culation Fan 1-1 f ailed to run af ter the startup button was released. It was also noted that both the local and remote indicating lights were lost. Attempts to reset the breaker and start the fan failed.

This placed the unit in the Action Statement of Technical Specification 3.6.4.2 which requires the one inoperable Containment Recirculation System to be restored to an operable status within 30 days or be in at least Hot Standby within the next 6 hou rs.

Designation of Apparent Cause of Occurrence: Although the exact cause is unknown, the fcilure has been attributed to the buildup of a non-conductive film on the surfaces of the auxiliary controller contacts. Insufficient contact prevented the auxiliary coil from operating.

Analysis of Occurrence: There was no danger to the health and safety of the public or to unit personnel. The standby Containment Recirculation F in 1-2 was operable and would have provided air circulation for hydrogen dilution in ihe event of a loss of coolant accident.

Corrective Action: The controller and breaker for Recirculation Fan 1-1 was inspected for loose connections and contacts. The contacts were inspected and cle'aned under Maintenance Work Order 79-1233. Containment Recirculation Fan 1-1 was operationally tested and declared operable. The unit was removed from the Action Statement of Tech-nical Specification 3.6.4.2 at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on January 10, 1979.

Failu re Da t.n : There have been no previous reported occurrences of Containment Recir-culation Fans failing to run.

LER #79-008