English 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.
