ML20064L009
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g7 7 jg8) decisional document not This is an internal, pre-necessarily representing a position of AE0D or NRC.
MEMORANDUM FOR:
Carlyle Michelson, Director Office for Analysis and Evaluation
$D 2//
of Operational Data
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FROM:
Matthew Chiramal Office for Analysis and Evaluation of Operational Data
SUBJECT:
BRUNSWICK 2 DIESEL GENERATOR JACKET WATER TEMPERATURE CONTROL VALVE AND MANUAL BYPASS VALVE (LER NO. 50-324 66 FOLLOWUP)
Event
Description:
On July 14, 1981, while performing the monthly load test on Diesel Generator 2 (DG2),.the diesel generator tripped and locked out due to jacket water temperature exceeding the trip set ~poin.: of 2000F. The trip occurred due to operator error in not adequately monitoring the jacket water temperature during adjustment of the temperature control manual bypass valve.
Discussion of Event:
DG-2 (,like the other three diesel generators at this station) has an automatic temperature control valve in 'ts jacket cooling water system.
DG-2, however, has been operating with the automatic temperature control valve inoperable and the manual bypass valve around the automatic valve adjusted for full load operation. Thus, the diesel generator was fully operable and capable of performing its design functions.
The monthly load test of DG-2 requires the adjustment of the bypass valve to control jacket water temperature at various generator loads. During these adjustments, the operator allowed the temperature to exceed the trip set point i
and caused the unit to trip and lock out.
Following the trip, the diesel was l
restarted and the monthly test was satisfactorily completed. At the completion of the test, the manual bypass valve was once again placed in the required position for full load operation of the DG.
Finding:
DG-2 has been operating with its automatic jacket water temperature l
control valve inoperable. However, the manual bypass has been adjusted to compensate for the loss of the automatic valve and the DG is operable and capable of perfonning its design functions. When the automatic control valve is repaired, the jacket water cooling system of DG-2 will be fully operational again.
The LER did not contain the information regarding the inoperable automatic i
temperature control valvc'. Most of the information discussed above was obtained I
in separate telecommunications with the licensee (Project Manager in attendance) and the resident inspector.
I recommend no further AEOD action on this event.
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6OON Matthewthlramal Office for Analysis and Evaluation of Operational Data cc: JVanVleet, NRR
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