A computerized plutonium laboratory-stack monitoring system

The Los Alamos Scientific Laboratory has recently designed and constructed a Plutonium Research and Development Facility to meet design criteria imposed by the United States Energy Research and Development Administration. A primary object of the design criteria is to ensure environmental protection and to monitor reliably plutonium effluent via the ventilation exhaust systems. A facility exhaust air monitoring system is described which establishes near ideal conditions for evaluating plutonium activity in the stack effluent. Total and static pressure-sensing manifolds are incorporated to measure average velocity and integrated total discharge air volume. These data are logged at a computer which receives instrument data through a multiplex scanning system. A multipoint isokinetic sampling assembly with associated instrumentation is described. Continuous air monitors have been designed to sample from the isokinetic sampling assembly and transmit both instantaneous and integrated stack effluent concentration data to the computer and various cathode-ray tube displays. The continuous air monitors also serve as room air monitors in the plutonium facility with the primary aim of timely evacuation of personnel if an above-tolerance airborne plutonium concentration is detected. Several continuous air monitors are incorporated in the ventilation system to assist in identifying release problem areas. (author)