The radiological calculation methodology of Jules Horowitz Reactor´s hot cells

Jules Horowitz Reactor (JHR) is an international project aimed on the construction of new high-performance nuclear reactor for research on materials and nuclear fuel (Material Testing Reactor, MTR). The Czech Republic - based Research Centre Rez Ltd. is responsible for the development and delivery of the hot cells prototype. Hot cells are used for handling of nuclear fuel and irradiated materials (samples, waste) by remote controlled manipulators, cranes and other equipment. It is very important to ensure and computationally demonstrate compliance with radiological conditions around the reactor hot cells. Such calculations are carried under 3D numerical transport code based on Monte-Carlo method - MCNPX. In order to have model with closest resemblance to real situation, the MCNPX input computer model is created according to the model from CATIA program. It is necessary to find the radiologically most affected place to calculate dose. This is followed by determination of the worst source position. After evaluation of the radiologically most affected place and the worst source position the final calculation runs in two phases: (1) in the first phase the dose is calculated from the γ source (2) in the second phase the dose is calculated from neutron source and γ radiation coming from secondary reactions (n, γ). The total dose is the sum of above-given three values and their errors at 95% probability level, i.e. 2 σ.