Seiler F A, Newton G J, Guilmette R A
Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM.
Health Phys. 1988 May;54(5):503-15. doi: 10.1097/00004032-198805000-00002.
Disposal of radioactive wastes in underground facilities requires continuous monitoring for airborne radioactive materials, both on the surface and underground. In addition to a natural background of nonradioactive and radioactive aerosols, there may be a sizeable dust contribution from ongoing work such as mining and vehicular traffic. In the monitoring of alpha-emitting radionuclides, these aerosols may lead to self-absorption in the source and a deterioration of the energy spectrum of the detected alpha particles. In this paper, the influence of a realistic background aerosol on the performance of an alpha monitoring system is evaluated theoretically. It is shown that depositing alpha emitters and background aerosol on a surface for counting leads rapidly to a considerable loss of counts, a deterioration of the alpha spectra, an eventual saturation of the count rates, and interference from the natural background of Rn daughters.
