Analysing the performance of radiological monitoring network during nuclear accidents

Abstract

JRODOS was used to simulate the dispersion of airborne radioactive material from a point source over the period 2012–2015. In total, 1331 radioactive plumes were simulated with the objective to investigate the influence of changes in meteorological conditions in the performance of the monitoring network. For this purpose, the existing set of 84 monitoring stations included in the EUropean Radiological Data Exchange Platform (EURDEP) system in an area of 200 km around the source point is taken as reference. A methodology is presented for quantitative evaluation of the variability of the number of stations affected, the time of the first detection, the maximum registered and differences between the maximum values match in the network and in the simulated plumes. The results show seasonal differences in all of these parameters according to changes in the size and shape of the affected area due to meteorological conditions. There are large differences in the number of monitoring stations affected by the plumes, from 2 to 74; in the timing and location of the first alert given by the network, from 1 to more than 5 h and faster along the west-east axis from the source; and in level of maximum gamma dose rate detected by the monitoring stations, from 0.17 nSv/h in summer to 0.22 nSv/h in autumn. These results show the need to consider this type of analysis over the years in the design of monitoring networks and in the development of nuclear emergency preparedness and response (EP&R) plans.