Determination of storage history of fissile materials based on activation effect of concrete floors

In the fields of arms control verification, homeland security, and antiterrorism, the detection and tracing of fissile materials is an extremely important work. In this paper, a method for determining the storage history of fissile materials based on the activation effect of concrete floors is proposed. This method is expected to be applied in the detection and tracing of fissile materials. First, a Monte Carlo simulation program was developed using the JMCT software capable of simulating the neutron activation effect of materials. Second, the activation effect of concrete floors under the irradiation of fission neutrons from fissile materials was studied using the numerical simulation program; it was found that 7 radionuclides, including Na-24, Mg-27, and K-42, can be used to determine the storage history of the fissile materials. Finally, the yields and numbers of the activation products caused by natural neutron background in concrete floors were calculated, as well as the detection limits of the fissile materials based on the above method.