Modeling and Analysis of Radionuclide’s Transport and Source Term Evaluation Within Containment and Release to the Environment for Research Reactors

The subject of this work is to carry out a source term assessment for a Hypothetical Research Reactor (HRR) and the calculation of the radiological consequences in case of Loss Of Coolant Accident (LOCA), setting out the assumptions made and the bases for these assumptions.

In the Safety Analysis Report, the maximum hypothetical accident was analyzed following these steps:
-Estimation of fission product inventory in the core
-Estimation fission product release to the building
-Building release evaluation
-Downwind doses calculation: evaluation of dose consequences from a release;

In the event of an accident in a nuclear reactor, the authorities should be in position to implement the counter-measures necessary to protect the surrounding population from radiological and the environment consequences of any releases. It is therefore necessary to monitor the progression of the accident as soon as it is detected by the plant operator in order to forecast the future behavior of the reactor so as to be able to recommend to the government authorities the implementation of counter-measures within a time compatible with the control of the risk to the population. For that purpose, it is necessary to estimate the nature, amount and kinetics of the radioactive products likely to be released out of the installation. Then, it would be possible to use PC-COSYMA codes to decide the adapted counter-measures.