Determination of Failure Modes and Effects

DOE-STD-1052-93

6.6

The failure modes of the selected component and the effects or consequences of

failures need to be determined. Performing the failure mode and effects analysis

(FMEA) is a significant element of the problem component analysis. The significance

of the failure modes is then established to determine which modes need to be

evaluated for PM task enhancement or design changes.

6.6.1

Failure modes are the types or ways a component may fail. They may be

determined by reviewing the component's operating characteristics and how

it functions in the system.

6.6.2

Determine the plausible causes of each failure mode. Plant history may

provide additional information useful in determining the failure causes.

6.6.3

Determine the effects of the failure modes and evaluate them at the local,

system, and plant level to determine their effect. Local effects are those that

may be noted in the general vicinity of the failure. System effects are

problems that inhibit system functions or operations. Plant effects are

problems that impact more than one system or limit plant operation or power

generation. The following are examples of effects:

local effect - provides a local alarm or results in leakage or unusual

noise

system effect - causes loss of redundant equipment

plant effect - results in a power reduction or transient

When evaluating components with redundant trains, consider the

consequences of the failure mode as if the redundant train was not available.

NOTE:

There are other methods for considering redundant equipment.

The method described above may result in increased system

reliability.

Input and interviews from the operations staff and training materials also may

be used to identify failure effects.

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