ML19332A446

Recommends Corrective Actions to Be Implemented by Util to Provide Operators W/Accurate,Timely & Complete Info Re Status of Diesel Generator Control Sys Per IEEE Std 279-1971 & NRC 770407 Ltr

ML19332A446
Person / Time
Site:	Pilgrim
Issue date:	09/09/1980
From:	Epps R LAWRENCE LIVERMORE NATIONAL LABORATORY
To:	Shemanski P Office of Nuclear Reactor Regulation
References
RE-80-09-06, RE-80-9-6, NUDOCS 8009150522
Download: ML19332A446 (2)

Text

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September 9, 1980 RE 80-09-06 Mr. Paul Shemanski, Operating Reactors Assessment Branch Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

PILGRIM NUCLEAR POWER STATION, UNIT #1 (DOCKET NO. 50-293, LICENSE NO. DPR-35, TAC #07901, DIESEL GENERATOR CONTRJL AND ALARM CIRCUITRY

REFERENCES:

1. NRC letter to Boston Edison Company (BEC), dated April 7, 1977

2. BEC letter to NRC dated June 1, 1977, #77-51

3. LLL Report, UCID-18145, " STATUS OF EVALUATION AND-MODIFICATIONS OF DIESEL GENERATOR STATUS ANNUNCIATOR SYSTEMS AT VARIOUS U.S. NUCLEAR POWER PLANTS," October 1979 In their. letter [Ref. 1], the NRC requested that.BEC provide information on the status annunciator system for the diesel generators at their facility.

This request for information was prompted by reports from licensees, i.e.

LER's on incident where diesel generators failed to respond to automatic start signals'because control switches or lockout and shutdown relays were left in the shutdown condition by operators unaware of their status.

The principal reasons for this lack of awareness were:

1. The sharing of annunciator stations for both disabling and non-disabling alarm conditions, 2, woraing on annunciator windows for disabling conditions which did not specifically say a diesel generator emergenC) start was blocked,

3. disabling conditions which were not annunciated in the i Control Room.

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The licensee responded by letter [REf. 2], describing-the diesel' generator annunciator, system at the Pilgrim Nuclear Power Station. A review of the licensee's response and the LLL report [Ref. 3], has identified two areas of concern:

1. The position of the air supply SHUT-OFF valve is not annunciated to the Control Room.

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2. If the diesel generator.is in the TEST mode and the shutdown relay is energized, it appears that the alarm can be cleared in the Control Room after the local- alarm is cleared. This raises the following question - can the local alarm be cleared without clearing the shutdown relay? If so, an automatic start could be blocked if the local alarm were cleared without first reverting the-shutdown relay and the operators were not aware of it.

In order to provide the operators with accurate, timely and complete information pertinent to the status of the diesel generator control system, as required by IEEE Std. 279-1971 and MC letter of April 7,1977 [Ref.1],. the following corrective actions are required:

1. The condition of the Air Supply SHUT-OFF Valve must be annunciated in the Control Room.

2. The quescion about the condition of the shut-cown relay addressed in item 2 above must be answered ano if the condition.as outlined in it: ? above exists, then corrective r

action must be taken.

It is recommended that the licensee be informed of the above requirements and tnat corrective action be implemented.

Special Issdes Program Nuclear Systems Safety Program RCE:el Copy to:

M.H. Dittmore R.A. Victor