Methods for radionuclide determination in the environmental monitoring system of the German Democratic Republic

The National Board for Atomic Safety and Radiation Protection is responsible for the environmental surveillance of man-made and natural sources of radiation in the German Democratic Republic. Therefore, the Board performs monitoring programmes itself and controls monitoring programmes performed by other institutions. The aim of the programmes is to determine the radioactive contamination of environmental media under normal and accidental radiation conditions. To achieve comparable measuring results from all institutions involved in environmental monitoring the Board establishes the radionuclide determination procedures for environmental monitoring. In the paper a survey is given of the sample preparation, non-nuclide-specific enrichment and nuclide specific enrichment methods used. For low activity concentrations in samples as well as for radionuclide determination for which the production of special measuring samples is necessary, separation and preparation methods are described. The measuring methods used to determine radionuclide concentrations in environmental media include the following: the determination of α emitting radionuclides by use of integral and spectrometric α activity measurements; the determination of β emitting radionuclides by use of β anticoincidence arrangements as well as liquid scintillation spectrometers; and the determination of γ emitting radionuclides using highly effective NaI(Tl) scintillation detectors, high resolution p and n type HPGe detectors with well type, on-top and Marinelli geometries, and anti-Compton spectrometers. Lower detection limits for the activity measuring devices are presented and the specific uses of these devices under normal and accidental radiation conditions are discussed. (author). 2 figs, 3 tabs