ENVIRONMENTAL MEASUREMENTS WITH A COMPREHENSIVE NUCLEAR TEST BAN TREATY RADIONUCLIDE PARTICULATE MONITOR

A Radionuclide Aerosol Sampler/Analyzer (RASA Mark 4) has been develop ed at PNNL for use in verifying the Comprehensive Nuclear Test Ban Tre aty (CTBT). The RASA Mark 4 collects about 20,000 m(3) of air per day on a 0.25 m(2) filter. This filter is automatically decayed for 24 hou rs, then advanced to a germanium detector for a 24 hour count. This sy stem has been operated in Richland WA for a limited period of time in a predeployment testing phase. The germanium-detector gamma-ray spectr a have been analyzed by automatic spectral analysis codes to determine Minimum Detectable Concentrations (MDC) for a number of isotopes of i nterest. These MDC's have been compared to other atmospheric measureme nts in the field and in the laboratory.