Calculation of multigroup reaction rates for the Ghana Research Reactor -1 fuel lattice cell using the WINSD/4 Transport lattice codes

Abstract

A 4-energy multigroup calculation of neutron reaction rates for absorption, fission,n*fission nuclear reactions have been performed at room temperature (293 K) for six resonance absorbers or isotopes: U234, U235, U238, Pu239, Pu240 and Pu241 of a five-region fuel lattice cell of the Ghana Research Reactor-1 using the WIMSD/4 transport lattice code. The corresponding number of nuclear reactions occurring in the fuel material of the lattice cell was also computed for the U235 fissile resonance absorber. The discrete ordinate spatial model, which pro-vides solution to the differential form of the transport equation by the Carlson-SN (N=4) approach was adopted to solve the Ludwig-Boltzmann multigroup neutron transport equation for this analysis. The results show that for any fissile resonance absorber, the reaction rates increased from the fast energy group, followed by thermal group 1 (higher end of thermal energy range), the resonance energy, and peaking for thermal group 2 (lower end of the thermal range). On the contrary, the absorption reaction rates were highest in the resonance energy range for the fertile absorbers.

Journal of Applied Science and Technology (JAST) , Vol. 5, Nos. 1 & 2, 2000, pp. 14 - 24