Definitions - Continued

DOE-STD-1052-93

3.13 FAILURE-FINDING TASK - A task performed to discover hidden failures when

no other tasks are judged to be applicable and effective in detecting degradation in

component performance.

3.14 FAILURE MODE - The particular type or manner of failure. A failure mode

describes what may or has happened as opposed to what caused it to happen. For

example, a motor-driven pump fails to run or a circuit breaker fails to open are

different kinds of failure modes.

3.15 FAILURE MODE AND EFFECTS ANALYSIS (FMEA) - A technique used to

determine significant failure modes of critical components by analyzing the effect of

the failure on a system or the plant and the likelihood of the failure mode to occur.

3.16 FAILURE RATE - The actual or expected number of failures for a given type of

component in a given time period. For example, the failure rate of a capacitor may

be specified as the number of short circuit failures per million capacitor hours. While

the failure rate of an item is often a function of time, it also may depend on such

factors as the number of operating cycles or environmental conditions.

3.17 FUNCTION - The actions or requirements that a component or system should

accomplish, sometimes defined in terms of performance capabilities.

3.18 FUNCTIONAL FAILURE - A failure that results in a loss of component or system

function(s). The failure may be active or passive, evident or hidden.

3.19 IMPLAUSIBLE FAILURE - A failure from a rare or unexpected failure mechanism

during the service life of the component while operating under normal or emergency

conditions.

3.20 FUNCTIONALLY CRITICAL, EQUIPMENT (FCE) - Equipment whose failure

results in a loss of system function or whose frequency and severity of failure have

an adverse impact on plant operation. FCE may be an individual component or an

entire subsystem.

3.21 MASTER EQUIPMENT LIST (MEL) - A detailed master list of structures, systems,

and components (SSC) to be included in the maintenance program. The list should

include both safety-related and nonsafety-related SSC.

3.22 MEAN-TIME-BETWEEN-FAILURES (MTBF) - The average or expected value

of operating time between failures of a repairable item.

3.23 PREVENTIVE MAINTENANCE - Predictive, periodic, and planned maintenance

actions taken to maintain a component within design operating conditions and extend

its life. Preventive maintenance actions may include operator rounds, engineering

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