Ontwikkeling van een nieuwe TLD-meetmethode voor het RIVM monitoring meetnet. Meting van de grootheid omgevingsdosisequivalent H*(10)

Abstract

This report describes the development of a new monitoring network, using thermoluminescence, for measuring the ambient dose equivalent. The network is being developed to replace the existing network at the nuclear power plants at Borssele and Dodewaard, at Emsland and at RIVM. Also a network is placed at the COVRA, where during 1991 the background radiation level, before storage of nuclear waste, was measured. Experiments were performed to test the linearity, the detection limit, the dependence on angle of incidence of the radiation, the energy-responsivity and the fading. The experiments show that the dosimeter meets almost all the requirements of an environmental dosimeter. Only the fading of the pellets is not well understood at this moment. It varies over 20% during comparable periods of time and circumstances. Additional experiments are required. Finally a comparison between this method and the one used up to this moment at the nuclear power plants at Borssele and Dodewaard is discussed. Only then a similar trend is observed in the dose-equivalent rate over the two monthly periods when the values of the new method are corrected for fading. There is however a difference in absolute value between the two methods.