ML18348A372

Provide Additional Information Related to Diesel Generators Control Circulatory, as Requested

ML18348A372
Person / Time
Site:	Palisades
Issue date:	07/07/1978
From:	Hoffman D Consumers Power Co
To:	Ziemann D Office of Nuclear Reactor Regulation
References
Download: ML18348A372 (4)

Text

• * * 'ATO* fllE COPY consumers . Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201

• Area Code 517 788-0550 July 7, 1978 Director, Nuclear Reactor Regulation Att: :M.r Dennis L Ziemann, Chief' Operating Reactors Branch No 2 US Nuclear Regulatory Commission Washington, DC 20555 DOCK.ET 50-255 -LICENSE DPR-20 -PALISADES PI..ANT -DIESEL GENEFATORS CONTROL CIRCUITRY AND ALARMS CJ cl: ---\ ....... t:':'l _,,.-.

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r:o:; =ic -f CJ ..... In the NRC review of previous Consumers Power submittals, dated May 16, 1977 and July 12, 1977 related to diesel generators control circuitry at the Palisades Plant additional information was requested.

The information requested and responses are as follows: Item 1 11 determine if the diesel generators are provided with a manual shutdown lockout relay .** " Response A manual shutdown relay does not exist in the Palisades Plant diesel generator control circuitry Item 2 "verify that an alarm is -provided.

which clearly indicates when the diesel ge11erator control switch is not in the automatic position ..* " Resuonse The diesel generator control switch is always in the automatic position, except during testing. An indicator light on the control panel indicates when the switch is in the automatic position

• Item 3 11 verify that all shared. ar!nunc1ar,ors for disabling c*Jnd.iticns cannot be until all condi ti ens a:re correete:i. " clearecL ..

2

• Response *

• Shared annunciators cannot be cleared until all abnormal conditions are cleared. To assist NRC staff in completing their review of this subject all previous responses are attached for clarity. Also, reference Consumers Power responses dated January 20, 1978 and February 2, 1978 (Diesel Generator Questionnaire) for additional information.

Assistant Nuclear Licensing Administrator CC: JGKeppler, USNRC

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• ATTACHMENT Diesel Generators Control Circuitry and Alarms The following information is provided in response to your March 29, 1977 letter relating to alarm and diesel generator control circuitry for the Palisades Plant diesel generators.

Item (a) "All conditions that render the diesel generator incapable of responding to an automatic emergency start signal **** " Response (a) The following condition relays operate the shutdown relay which renders incapable of automatic start: 1. Generator differential relay. 2. Overcrank relay

• 3. Jacket water temperature relay. 4. Overspeed relay. 5. Oil pressure relay 6. Loss of direct current control relay. Item (b) 11 The wording on the annuhciator window in the cont:::-ol room that is alarmed for each of the conditions identified in (a).11 Resnonse (b L The control room annunciator windows and the condition in (a) above which operates them: 1. Diesel Generator Breaker Trip 2. 3. Generator differential relay. Diesel Generator Fail To Start Overcrank relay . Diesel Generator Trouble a. Jacket water temperature relay. 1::. Ov-erspeed relay. c. Oil pressure relay. d. .Loss of d-c control power.

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• Item (c) "Any other alarm signals that also cause the same annunciator to alarm. '1 Response (c) Other alarm signals which share the annunciators listed in'(b) above: 1. Diesel Generator Breaker Trip Breaker contact position switch. 2. Diesel Generator Fail To Start None. 3. Diesel Generator Trouble a. High lube oil differential pressure.

b. Low lube oil temperature.

c. High lube oil temperature.

d. Air supply tanks low pressure.

e. Jacket water level low. f. Low lube oil level g. Raw water pressure low

• h. Prelube pressure low. Item (d) "Any condition that renders the diesel generator incapable of responding to an automatic emergency start signal which is not alarmed in the control room." Item (d) Resnonse Jacket water pressure low will not prevent auto start. This is the dition when the engine is not running. A high jacket water pressure will prevent the engine from starting. (The cranking relay will be isolated.)

The reason for this is that a high jacket waterpressureindicates that the engine is running. This is the signal that turns off the starting motor after an engine start signal. Jacket water pressure is supplied only by the engine-driven water circulating pump. Item (e) "Any pr9posed modifications resulting from this evaluation." Item (e) Response The jacket water pressure will not be alarmed. A low pressure is normal while the engine is shut down. A high pressure is normal while the engine is running

• A high jacket water pressure is an impossible condition if the engine is not running for the following reasons: 1. Jacket water pressure is supplied only by the engine-driven water pump. 2. The cooling system is vented to at the cooling expansion tank.