Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The planned MYRRHA research reactor in Mol (Belgium) aims to demonstrate efficient transmutation of high level waste and associated Accelerator-Driven Systems (ADS) technology. The system is based on a lead-bismuth eutectic (LBE) cooled reactor, working both in critical and in sub-critical operation modes. The neutrons needed to sustain fission in the sub-critical mode are produced via spallation processes by a 600 MeV, 4 mA proton beam, which is provided by a linear accelerator and hits a LBE spallation target located inside the reactor core. In order to assess the main shielding problems, a method based on the combined use of the two Monte Carlo codes MCNPX and FLUKA has been developed, with the goal to perform detailed analyses of both the radiation fields due to the system in operation, and the coupled residual radiation due to the activated materials. As a result, neutron and photon fluences as well as prompt and residual ambient dose equivalent rates have been evaluated. In addition, an activation database for many of the structural materials has been built.