Simplified, solid-state, wide-range, stack-gas monitor for nuclear power plants

Government regulations require that radioactive effluent from nuclear power plants be measured and reported and that effluent reporting be based on la boratory analyses. Continuous monitoring during a postulated design-basis a ccident is also required. Wide-range gas monitors for satisfying regulatory requirements for post-accident radiation monitoring typically have been ve ry complex, and costly to operate and maintain. This paper describes recently developed solid-state detectors that can be m ounted directly in the vent stack of a nuclear power plant for monitoring g aseous effluent during normal and postulated accident conditions and also f or providing real-time isotopic analysis of the gaseous plant effluent. A p roposed stack-gas monitor system(1) using these detectors is described, inc luding anticipated signal levels based on calculations for an actual operat ing nuclear power plant (a pressurized-water reactor).