Nuclear Science and Engineering / Volume 35 / Number 3 / March 1969 / Pages 319-331
Technical Paper / dx.doi.org/10.13182/NSE69-A20010
Articles are hosted by Taylor and Francis Online.
A new theoretical formalism of the space-time kinetics is developed for heterogeneous reactor models. The basic time-dependent diffusion equation, which contains terms representing localized absorption and fast-neutron production by fuel rods, has been analytically transformed into a convolution integral form. This enables computation of space- and time-dependent flux for heterogeneous reactors by considering the sizes and spacings of the fuel rods, their geometrical locations, and the nuclear properties of the material used. Although the basic idea and mathematical formalism developed in this paper can be applied for various other space-time kinetics problems, the final calculation is performed for the forced oscillation problem. Two computer codes, HERMITS-1 and HERMITS-2, are developed. By using these codes, it is shown that contour maps of the static flux, phase angles, and amplitudes of neutron waves around the fuel rods can be calculated in an extremely short amount of machine time.