3D-cylinder reactor core neutron space-time kinetics is simulated with an improved quasi-static method. The program is developed. In a supposable 250 MW modular HTGR model, the core neutron space-time kinetics is simulated. Calculated results obtained from this program and CITATION code agree well with each other at initiatory state. Variance of the core reactivity, average neutron flux of each group, and relative power with time is computed.

This paper studies the problems about buckling feedback of spectral calculations in physical calculations of the reactor and presents a useful method by which the buckling feedback of spectral calculations is implemented. The effect of the buckling feedback in spectra and the broad group cross scetion, comvergence of buckling feedback iteration and the effect of the spcetral zones dividing are discussed in the calculations. This method has been used for the physical design of HTR-10MW Test Module.