Optimization of the biological shield of a typical modular reactor

For shielding against nuclear radiation, the low weight of the shield is very important. Shielding design is a multi-objective optimization problem. In the shielding design, first the parameters are estimated analytically based on the equations, and then the final design is done using calculation codes. However, in many cases, the designed shields lack the necessary optimization and it is necessary to optimize the initial design using known methods. In this research, in order to optimize the biological protection of a modular reactor, a multi-objective optimization method has been proposed to couple the PSO algorithm with the ANISN calculation code. Two objective functions of the component, including weight and radiation dose, are included in a multi-objective mathematical model. The overall objective function is a weighted linear combination of each of these two component functions. Materials used for optimization include concrete, composite including B4C and B2O3. The results show that the multi-objective optimization method for the biological protection design of a modular reactor is reliable and efficient. This method can improve the design quality of the shield and reduce the weight of the shield by 38% and reduce the total dose rate of neutrons and photons by 83%, compared to the case where the conventional shielding of the reactor well (serpentine concrete) is used.