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MEMORANDUM T0:
File FROM:
Wayne D. Lanning
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g Office for Analysis and Evaluation of g
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Operational Data
SUBJECT:
DELIBERATE PUMP TRIP AT BROWNS FERRY, UNIT 2 ON APRIL 6, 1981 Manipulation of control switches for two trains of the circulating water systems resulted in the tripping of two circulating water pumps located in the intake structure.
It could not be determined whether the valves on the discharge of the pumps were closed or the pumps were tripped directly; nor could it be determined whether.the switches were manipulated at the
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remote panel or locally in the valve room. The third pump remained operable.
The loss of these pumps affects condenser vacuum and does not affect the safety of the plant.
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Upon receipt of a low condenser vacuum alarm in the control room, the operators began a load reduction from 100% power, and an auxiliary operator promptly restarted the pumps within five minutes.
The FBI conducted an investigation (Enclosure) and found no evidence of who operated the switches. TVA's investigation produced the same results.
Eight steam fitters and carpenters were in the intake structure at the time.
An auxiliary operator is stationed in the intake structure. Access to the intake structure is controlled by key card. According to the Station Super-intendent, the only safety-related equipment located in the intake structure are the RHR service water pumps which are located in a locked room controlled by key card.
This event will be listed in the safeguards watch list.
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M ay e D. Lannin Office for An is and Evaluation g
of Operation Data
Enclosure:
Investigation Report, U.S.
c Department of Justice, Federal Bureau of Investigation, i!
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File BH 117-18, dated 5/22/81 J
cc:
C. Michelson J. Heltemes