Evaluation of passive alpha detectors for sensitive/inexpensive /fast characterization of radiological contamination on surfaces and in soils

摘要

Passive alpha-particle detectors, originally developed for indoor radon measurements, offer the potential for cost-effective and sensitive measurements of radiological contamination in soils and on surfaces for field screening and radiological survey applications. We have carried out field demonstrations of electret ionization chambers (EIC's) and alpha track detectors (ATD's). The EIC's offer the advantages of immediate on-site readout, good sensitivity, ruggedness, and simplicity of operation. The use of parallel screened and unscreened EIC measurement allows the separation of alpha-particle response from radon/gamma/beta response. The advantages of the ATD's include the potential for hot-particle counting, permanent records of contaminated and post-remediation activity levels, and inexpensive depth profiling of contamination in soil. At this time, the ATD's are routinely shipped to the vendor after exposure in the field for processing and readout. It is feasible that the necessary processing and readout equipment could be deployed in a mobile laboratory for fast on-site analysis. We will present results from environmental measurements at the Nevada Test Site and indoor surface contamination measurements carried out at ORNL.