Inverse model investigation of radionuclide dispersion in a ventilated room based on the adjoint probability method

Abstract

The improved identification of radioactive pollutant leakage points in ventilated rooms is one of the key technologies for nuclear accident consequence assessment. Radionuclides disperse turbulently in ventilated rooms, and leakage locations lead to different concentration distribution patterns. Considering the effects of radioactive decay and deposition, an inverse model of radionuclide dispersion under ventilation conditions was established based on the adjoint probability method coupled with computational fluid dynamics (CFD). The airflow field was calculated by CFD, and the probability of leakage locations for the radioactive source was estimated by the adjoint probability method coupled with CFD. The results showed that the proposed model could help nuclear emergency decision-makers accurately trace the location of leakage sources and provide more scientific information for early emergency response and consequence assessment.