Design of optimised systems for monitoring of radiation and radioactivity in case of a nuclear or radiological emergency in Europe

After the Chernobyl accident many European countries installed monitoring networks which measures the radioactivity in the environment. Such a network was established in Norway in 1986, and replaced by a new network, Radnett, in 2006. The network is an ea rly warning system in case of a nuclear accident, and will provide the first values for the decision makers who will decide upon protective actions. The network design varies a lot in Europe; high or low density, even or uneven distribution, and choice of instrument. The DETECT project aims to develop a methodology and planning tool which will help European countries design new networks or improve existing ones. This will be archived through two steps. First conducting a radiological threat analysis bas ed on detailed atmospheric dispersion simulations corresponding to a variety of potential accidents. This includes accidents at a nuclear power plant, detonation of radiological explosive devices, accident on nuclear powered vessel, and radioactive releas es from other sources. Second step is the development of adequate evaluation criteria (cost functions) for monitoring networks. These criteria need to be identified but will include density, distribution, meteorological uncertainty, technical criteria, an d economical and social factors. It will also take into account the use of mobile monitoring systems. In the end the threat analysis and cost function will be combined to look at optimization of different monitoring strategies as a function of scenario. T he result of this analysis is a measurement of the quality of a network design compared to initial expectations. NRPA will use the outcome of the DETECT project to analyse the national monitoring network combined with other monitoring resources like car or airborne systems, and measurements done by the Civil Defence. This will give us a better understanding of the capacity of existing resources, and develop a long term plan for upgrades and improvements.