Shielding research of minitype reference radiation device based on Monte Carlo simulation

When applied the minitype reference radiation (MRR) to calibrate gamma ray dosimeters, the shielding structure of the MRR should meet the shielding technique demand, in which the limit dose rate of the outside surface of the MRR must be lower than 5 Sv/h. In order to optimize the shielding design of the MRR, Monte Carlo particle transport code MCNP is employed to simulate and analyze the dose distribution of the outside surface of the MRR. The results show that the dose distribution of each surface of the MRR can be described in detail with MCNP and it is conducive to complete shielding design. The lead-steel composite material is applied to increase the strength and reduce the weight of the MRR. The optimized weight of the MRR is about 271.9 kg.