Samples and Instrumentation - STD-1128-98master0100

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

be designed not only for prompt detection of airborne contamination, but to assure that

samples are representative of the air that the workers are breathing and have a low enough

limit of detection that only negligible doses could go undetected. Bioassay and in vivo

analysis of plutonium should confirm the negligible exposure that the air monitoring

program documents and provide a baseline for any accident- or incident-related exposures.

The need for an effective sampling and monitoring program is even more critical in the

rapidly changing environment of decommissioning activities.

Numerous factors enter into any determination of plutonium contamination levels and the

risk to workers. Some of these factors are detection efficiency of the measuring instrument,

collection efficiency of the smear media or air sample filter, the location of the smear or air

sample in relation to the source of contamination, the physical and chemical properties of

the contamination, the representativeness of the air sample to the air being breathed by the

worker, the engineered controls available, and the protective equipment used. All of these

factors must be considered in the development of a plutonium contamination control

program and in evaluating the actions required for personnel protection.

4.1.5 Samples and Instrumentation

For plutonium facilities, both air sampling and air monitoring are essential elements of the

radiological control program. Real-time air monitoring using alpha-sensitive continuous air

monitors (CAMs) should be used to alert workers to rapid degradation of radiological

conditions. The air sampling system with a lower limit of detection must be adequate to

provide continuing assurance that personnel exposures are within limits and ALARA.

The characteristics of a good plutonium CAM include

-- A lower limit of detection equal to or better than 8-DAC-h

-- high reliability with a minimum of spurious alarms

-- a stable and constant flow air mover

-- stable and documented detector efficiency with geometry, filter collection efficiency,

self-attenuation, etc., considered

-- methodology for radiation discrimination and natural radioactivity discrimination

-- system for activating an alarm

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