An International Peer - Reviewed Journal by Nuclear Science & Technology Research Inistitute

Document Type : Research paper


1 Nuclear Science and Technology Research Institute

2 Nuclear Physics and Accelerators Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran


Abstract: One of important factors of a nuclear reactor core, is fast fission factor. In this paper, this parameter is calculated based on a space and energy dependent method using PTRAC card of MCNPX code. Tehran research reactor (TRR) is taken as a case study and analyses of the parameter are performed on the reactor core. Fast fission factor in TRR is evaluated regarding temperature effect, control rod positions, and fuel assembly positions. Using PTRAC card, useful information on fast fission factor is achieved throughout the reactor core. One MCNPX run return a data file containing data about neutron interaction which can be analysed many times in different manners to reveal useful information. The method is simple and can be applied to any nuclear reactor core. The results obtained by the method can help nuclear reactor designers and nuclear reactor fuel managers to have a precise evaluation of the parameter. The method proposed in this paper for fast fission factor calculation is compared with the results previously published in the literature.