ENVIRONMENT The system operates by drawing air at a rate of 566 litres/min through a membranefilter paper for a fixed period and then passing the filter containing the sampled particles in front of four niggedized surface barrier detectors. The detector chamberis evacuated to prevent the interaction of alpha Washington) during the summerof 1978. The Z-plant is a chemical processing facility that converts plutonium nitrate to oxide or metal, recovers and dissolves scrap, and Polonium-214 a five-fold increase in resolution). The sample is then counted and the results analyzed while another sample is being collected. The entire process is controlled by an LSI11 microprocessor. The system can of plutonium-238 and/or Polonium-218 Bismuth-212 Plutonium-238 Americium-241 Plutonium-239 Counts vance thefilter paper, and pump the detector chamber back downto 20 mm of Hg in about 22 seconds. Figure 3 shows the actual sampling hardware used. Figure 4, an alpha spectrum of a stack sample collected by TAMS at the Rockwell Hanford Operation plutonium-recovery facility, illustrates the spectral resolution of the system. The three peaks on the right are caused by the radon222-radon-220 daughters, polonium-218, bismuth-212, polonium-214, and polonium-212. The peak resulting from polonium214 has a full width at half maximum of about 100 keV. Thefirst peak on the left indicates the presence of plutonium-239, and the second indicates the presence about 71 O00 litres/min. Our Polonium-2?12- "particles with air (and thus produce vent the detector chamber, ad- also separates americium from plutonium. The exhaust stack is about 8m high and 36cm in diameter with an effluent flow of Energy Pig. ah Alpha spectrum of a 60-min stack sample collected by TAMS at a plutonium facility. The three peaks on the right are caused by the radon-222-radon-220 daughters, polonium-218, bismuth212, polonium-214, and by polonium 212. The first peak on the left indicates the presence of plutonium-239, and the second indicates the presence of plutonium-238 and/or americium-241, Note that TAMS can resolve plutonium239 from the combined plutonium-238 and americium- 24]. americium-241. Field results The TAMS system wasfieldtested at the Rockwell Hanford Operation plutonium-recovery facility’s Z-plant (in Richland, 17