Direct internal dosimetry. A new way for routine incorporation monitoring of γ-emitting radionuclides

The INDOS detector system offers the following advantages with respect to routine incorporation monitoring: The measurement is performed automatically and there is no need for trained staff. The measuring time is short and thus a relative large number of persons may be monitored with a relative high measuring frequency. First estimates of the individual effective dose equivalent rate are available immediately after the measurement. 1) The direct determination of the dose equivalent in principle is more precise than the conventional procedures for internal dosimetry, because (i) the retention of radionuclides in the body may be measured explicitly and (ii) the dependence of the dose equivalent on the body proportions is corrected implicitly. 2) The measuring procedure is comparable to the external dosimetry with respect to accuracy and lower limit of detection. Thus, the results of internal and external dosimetry can be summed up in an easy and reasonable manner. 3) The detector system can be installed in any building; it also can be installed as a mobile unit in a car or a container for long distance transportation by aircraft or train. 4) Last but not least, the cost for monitoring with INDOS is much lower than for the conventional monitoring procedures using whole body counters. (author)