Method 1

DOE-STD-1052-93

plant-life extension and aging studies

personnel safety statistics

The following are two methods that may be used to select and prioritize plant

systems:

7.1.1

Method 1

A system prioritization survey may be performed by developing a list of

important criteria. Select and request managers, supervisors, engineers, and

knowledgeable craftspersons to complete the survey for each system

considered for enhancement. Each system should be evaluated by assigning

weighting factors from 1 to 10 to each criterion (i.e., 1-lowest, 10-highest)

and then determining an overall importance value for each system by

summing the factors.

The importance values provided by all personnel performing the evaluations

should be summed for each system, and each system should be ranked in

descending order. The systems with the highest ranking should be the ones

considered when selecting the system to be evaluated first.

7.1.2

Method 2

This method is directed at improving nuclear plant safety through

improvement to overall plant performance by focusing on system availability

data (i.e., unplanned shutdown days and unplanned outage extension days)

and the results of system prioritization surveys as they are described in Step

7.1.1. The survey and unavailability data are then scaled to reflect their

relative magnitude. Next, the scaled values are multiplied by a weighting

coefficient and summed to yield a composite score. These scores are then

ranked in descending order.

Some suggested weighting coefficients are shown below:

Unplanned days off-line (UDOL) = 1.0

Surveillance unavailability hours (LCO) = 0.04 (Mode 1)

In-plant survey = 0.1

Unplanned days off-line include scrams, forced outages, and outage

extension days. Surveillance unavailability hours include time spent in

limiting conditions for operation (LCO) action statements resulting from

maintenance surveillance testing and corrective maintenance.

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