ML20204H376

Special Rept 87-2:on 870310,fire Pump House Failed to Swap Alternate Power Source After Group Bus 1F Taken Out of Svc, Causing Loss of Ac Power to Auto Start Initiation Logic for Both Diesel Driven Fire Pumps.Caused by Equipment Failure

ML20204H376
Person / Time
Site:	Salem
Issue date:	03/19/1987
From:	Zupko J Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
87-2, NUDOCS 8703260624
Download: ML20204H376 (3)

Text

O PSEG .

Public Service Electric and Gas Company P O. Box E Hancocks Bridge, N+w Jersey 08038 Salern Generating Station March 19, 1987 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSB NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 REPORT 87-2 SPECIAL REPORT This Special Report describes the circumstances surrounding a loss of AC power to the auto start logic for the diesel fire pumps.

This report is being submitted in accordance with the reporting requirements of Technical Specification Action Statement 3.7.10.1.b.

Sincerely yours,

^

JL/

G703260624 G70319 2 J. . Zupko, Jr.

PDR ADOCK 0500 General Manager-U Salem Operations RKilipc Distribution M g The Energy Poophi

SPECIAL REPORT NUMBER 87-2 r

PLANT IDENTIFICATION:

Salem Generating Station - Unit 1 Public Service Electric & Gas Company H:ncock's Bridge, New Jersey 98038 IDENTIFICATION OF OCCURRENCE:

FAILURE OF THE 115VAC CONTROL CENTER TO SWAP TO ITS ALTERNATE POWER SOURCE RESULTING IN A LOSS OF AC POWER TO THE AUTO START LOGIC FOR BOTH FIRE PUMPS Event Date(s): 03/19/87 Report Date: 93/19/87 This report was initiated by Incident Report No.87-987 CONDITIONS PRIOR TO OCCURRENCE:

Mode 5 - Rx Power 94 - Unit Load 9 MWe DESCRIPTION OF OCCURRENCE:

On March le, 1987, at 9648 hours0.112 days <br />2.68 hours <br />0.016 weeks <br />0.00367 months <br />, No. IF Group Bus was taken out of service in support of work on No. 12 Station Power Transformer. When the group bus was tagged, the ll5VAC Control Center located in the Fire Pump House failed to swap to its alternate power source, the No.

2H Group Bus, resulting in a loss of AC power to the auto start initiation logic for both diesel driven fire pumps. With the loss of AC power, both of the fire pumps started as designed and an alarm was received. When Fire Protection Department personnel investigated the alarm, they found the diesel fire pumps operating and notified the Control Room of the situation. Action Statement 3.7.10.1.b was entered. The fire pumps were placed in manual control and secured.

In accordance with the provisions of Technical Specification Action Statement 3.7.10.1.b, an operator was stationed to start the fire pumps if necessary. Site Maintenance was subsequently notified of the failure of the 115VAC Control Center to swap to its alternate power sourco.

In accordance with the requirements of Technical Specification Action l Statement 3.7.19.1.b, the NRC was notified at 1955 hours0.0226 days <br />0.543 hours <br />0.00323 weeks <br />7.438775e-4 months <br /> the same day. A written confirmation was submitted to the NRC on 3/11/87.

On 3/11/87 at 1239 hours0.0143 days <br />0.344 hours <br />0.00205 weeks <br />4.714395e-4 months <br />, No. IF Group Bus was returned to service and power was restored to the diosol fire pump auto start initiation logic. The fire pump controls woro returned to " automatic" and the Action Statement was terminated.

APPARENT CAUSE OF OCCURRENCE:

Upon investigation, the " root cauno" of this occurrence has been determined to be equipment failure. Tho 115VAC Control contor failed to swap to its alternato power sourco due to a failed transfer switch.

UNIT 1 SPECIAL REPORT 87-2 r ANALYSIS OP OCCURRENCE:

With the loss of AC power, due to the failure of the ll5VAC Control Center to transfer to its alternate power source, the fire pump auto start initiation logic required by the Technical Specifications is inoperable. Stationing an operator at the pumps to manually start the pump if required is an acceptable compensatory action to provide backup fire suppression capability. There would be a delay in starting the pump depending on the time it took the Control Room or the operator to recognize the need for the pumps and the time it took to start them. Additionally, there la a backup fire suppression supply from llope Creek Generating Station, which could be aligned to supply the Salem system.

The diesel fire pumps started, as per design, on the loss of AC power to the auto start initiation logic. In the event of an emergency, adequate water volume and pressure would have been available to the fire suppression header. Therefore, this occurrence involved no undue risk to the health and safety of the public.

Due to the loss of AC power to the auto start initiation logic, this event is considered to be reportable in accordance with the requirements of Technical Specification Action Statement 3.7.10.1.b.

CORRECTIVE ACTION:

The fire pumps were placed in manual control with an operator stationed to start them as required. Power was subsequently aligned to the fire pump auto start initiation logic from No. 1P Group Bus, and the pumps were restored to automatic control. A new auto transfer switch will be installed upon receipt from the manufacturer.

No further corrective action is deemed necessary.

U Lt-h d General Manager -

Salem Operations RKilipc SORC Mtg.87-017 i