ASTM International

Standard Guide for In-Plant Performance Evaluation of Automatic Pedestrian SNM Monitors
 N C993

Annotation

This guide is affiliated with Guide C1112 on applying special nuclear material (SNM) monitors, Guide C1169 on laboratory performance evaluation, Guide C1189 on calibrating pedestrian SNM monitors, and Guides C1236 and C1237 on in-plant evaluation. This guide to in-plant performance evaluation is a comparatively rapid way to verify whether a pedestrian SNM monitor performs as expected for detecting SNM or SNM-like test sources.

In-plant performance evaluation should not be confused with the simple daily functional test recommended in Guide C1112. In-plant performance evaluation takes place less often than daily tests, usually at intervals ranging from weekly to once every three months. In-plant evaluations are also more extensive than daily tests and may examine both a monitor's nuisance alarm record and its detection sensitivity for a particular SNM or alternative test source.

In-plant performance evaluation also should not be confused with laboratory performance evaluation. In-plant evaluation is comparatively rapid, takes place in the monitor's routine operating environment, and its results are limited to verifying that a monitor is operating as expected, or to disclosing that it is not and needs repair or recalibration.

In-plant evaluation is one part of a program to keep SNM monitors in proper operating condition. Every monitor in a facility is evaluated. There are two applications of the in-plant evaluation: one used during routine operation and another used after calibration.

Routine Operational Evaluation—In this form of the evaluation, nuisance alarm records for each monitor are examined, and each monitor's detection sensitivity is estimated during routine operation. The routine operational evaluation is intended to reassure the plant operator, and his regulatory agency, that the monitor is performing as expected during routine operation. This evaluation takes place without pretesting, recalibration, or other activity that might change the monitor's operation, and the evaluation simulates the normal use of the monitor.