High-pressure plastic scintillation detector for measuring radiogenic gases in flow systems

Radioactive gases are emitted into the atmosphere from nuclear electric pow er and nuclear fuel reprocessing plants, from hospitals discarding xenon us ed in diagnostic medicine, as well as from nuclear weapons tests. A high-pr essure plastic scintillation detector was constructed to measure atmospheri c levels of such radioactive gases by detecting the beta and internal conve rsion (IC) electron decays. Operational tests and calibrations were made th at permit integration of the flow detectors into a portable Gas Analysis, S eparation and Purification system (GASP). The equipment developed can be us ed for measuring fission gases released from nuclear reactor sources and/or as part of monitoring equipment for enforcing the Comprehensive Test Ban T reaty. The detector is being used routinely for in-line gas separation effi ciency measurements, at the elevated operational pressures used for the hig h-pressure swing analysis system (2070 kPa) and at flow rates of 5-15 l/min [1,2]. This paper presents the design features, operational methods, calib ration, and detector applications. (C) 1999 Elsevier Science B.V. All right s reserved.