ML19259B788

Forwards LER 79-029/01T-0

ML19259B788
Person / Time
Site:	Davis Besse
Issue date:	03/16/1979
From:	Murray T TOLEDO EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19259B789	List: ML19259B788 ML19259B790
References
FOIA-79-98 L79-184, NUDOCS 7903230161
Download: ML19259B788 (1)

Text

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g___ TOLEDO u EDISON March 16, 1979 L79-184 FILE: RR 2 (NP-32-79-02)

Docket No. 50 '5 License No. N1.-3 Mr. James G. Keppler Regional Director, Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Connission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

Reportable Occurrence 79-029 Davic-Besse Nuclear Power Station Unit 1 Date of Occurrence: March 6, 1979 Enclosed are three copies of Licensee Event Report 79-029 with a supplemental information sheet which is being submitted in accordance with Technical Speci-fication 6.9 to provide 14 day written notification of the subject occurrence.

Yours truly, Y M O S % *ff l' X O 5' ,

Terry D. Murray Station Superintendent .

Davis-Besse Nuclear Power Station TDM/SNB/ljk Enclosure cc: Dr. Ernst Volgenau, Director Office of Inspection and Enforcement Enc 1: 40 copies LER 79-029 Mr. William G. Mcdonald, Director Office of Management Information and Progrcm Controi Encl: 3 copies LER 79-029 2 copies telecopy

?90323ersy THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISCN AVENUE TOLEDO. OHIO 43652

9 TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE PAGE 2 SUPPLEMENTAL INFORMATION FOR LER NP-32-79-02 Corrective Action: At 0415 hours0.0048 days <br />0.115 hours <br />6.861772e-4 weeks <br />1.579075e-4 months <br />, the Reactor Operator discovered that both DH7A and DH7B were closed and Lamediately opened them from the Control Room. Discipli-nary action was teken against the~ Auxiliary Operator.

Failure Data: There have been no previous similar events. There have been similar personnel errors previously reported in Licensee Event Reports NP-33-77-lli, NP-33-77-ll3, and NP-33-78-08.

LER #79-029

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 oa 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 BWSr 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, immediately 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 Acticn 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 BWSr.

The unit was in this Action Statement for approximately 6 minutes, 52 seconds. This report is being submitted in accordance with Technical Specification Designation of Apparent Cause of Occurrence: This incident was caused by personnel error. An operator mistakenly closed BWST 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 analy cd at this time.

LER #79-029