ML19259B771

Forwards Corrected Copy of Page 1 of Suppl Info for LER 79-029

ML19259B771
Person / Time
Site:	Davis Besse
Issue date:	03/19/1979
From:	Murray T TOLEDO EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
FOIA-79-98 L-79-187, NUDOCS 7903230128
Download: ML19259B771 (2)

Text

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J' C TOLEDO u EDISON March 19, 1979 L79-187 FILE: RR 2 (NP-32-79-02)

Docket No. 50-346 License No. NPF-3 Mr. James G. Keppler Regional Director, Region III Office of Inspection and Enforcement U. S. Nuc1 car Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

Enclosed are three corrected copies of Page 1 of the supplemental information for Licensee Event Report 79-029.

Please remove and destroy the previous pages from your copies of this report, and replace with the attached, corrected pages.

Yours truly, W 0 N W ,j'/N B Terry D. Murray Station Superintendent Davis-Besse Nuclear Power Station TDM/SNB/ljk Enclosures cc: Dr. Ernst Volgenau, Director Office of Inspection and Enforcement Enc 1: 30 copies LER 79-029 Mr. William G. Mcdonald, Director ,

Office of Management Inf ormation and Program Control Enc 1: 3 copies LER 79-029 790323ot2S THE TOLEDO FOISON COMPANY EOISON PLAZA 300 MADISON AVENUE TOLEDO. CHIO 43552

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-32-79-02 DATE OF EVENT: March 6,1979 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Inadvertent closing of Borated Water Storage Tank (BWST) Isolation Valves DH7A and DH7B Conditions Prior to Occurrence: The unit was in Mode 1, with Power (MWT) = 2384, and Load (Gross MWE) = 790.

Description of Occurrence: During the 0000 to 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> shift on March 6, 1979, operations personnel were performing a valve lineup to drain down the Spent Fuel Pool per Clean Liquid Radwaste Operating Procedure, SP 1104.29, Modification T-3431. In accordance with this modification, the Control Room Reactor Operator ,

instructed an Auxiliary Operator to close BWST to Borated Water Recirculation Pump l-1 Valve, BW 7. At 04:08:25 hours, the Auxiliary Operator mistakenly closed BWST Isolation Valves DH7A and DH7B using their local. switches.

At approximately 0415 hours0.0048 days <br />0.115 hours <br />6.861772e-4 weeks <br />1.579075e-4 months <br />, the Auxiliary Operator returned to the Control Room and informed the Reactor Operator that he had closed DH7A and DH7B. The Reactor Operator realizing that closing DH7A and DH7B placed the unit in violation of a Technical Specification, i=nediately opened DH7A and DH7B from the Control Room.

The valves were both open at 04:15:17 hours on March 6, 1979.

Closing DH7A and DH7B placed the unit in the Action Statement of Technical Speci-fication 3.5.2 which states that two independent Emergency Core Cooling System (ECCS) subsystems shall be operable with each subsystem comprised of one operable high pressure injection pump, one operable low pressure injection pump, one opera-ble decay heat cooler, and one operable flowpath capable of taking suction from the BWFr.

The unit was in this Action Statement for approximately 6 minutes, 52 seconds. This 1 report is being submitted in accordance with Technical Specification 6.9.1.8f.

Designation of Apparent Cause of Occurrence: This incident was caused by personnel error. An operator mistakenly closed BUST outlet valves DH7A and DH7B instead of BWST to Borated Water Recirculation Pump 1-1 Valve BW 7.

Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. A signal from the Safety Features Actuation System would have opened DH7A and DH7B and fully restored the ECCS flowpath, but the 66 second open-ing time of the valves would have exceeded the 30 second valve safety position criteria of FSAR Section 6.3.4, "ECCS Test and Inspections". The consequences of this event are being analyzed at this time.

LER #79-029