Application of atmospheric dispersion modelling in finding optimal locations of early warning stations around a nuclear power plant

The paper investigates a practical problem of finding optimal locations of radiometric detectors for the automatic early warning measurements around nuclear facilities. The proposed methodology combines an analysis of the capabilities of different detectors with atmospheric dispersion modelling in the JRodos decision support system. It was found that the radioactive contamination after a small abnormal release might be impossible to detect for a less sensitive device (like a popular GM counter) further away than 5 km from the nuclear reactor. On the other hand, a more sensitive detector (like a 3" NaI scintillator) could be inappropriate for measurements within a shorter distance because the radiation field could be too high. This work was performed in the context of the planned first Polish nuclear power plant, but our approach and findings are general and apply to other facilities using a pressurised water reactor with electrical power of about 1 GW.