A calculational method is presented about the simulation of flow pattern of fuel elements in the physics calculation for Pebble Bed HTR. Then detailed calculation on 10MW HTR is described along with comparison of its results with that of a simplified computation without close simulation of the flow pattern of fuel elements in the reactor core.

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.

A method of burnup calulation is introduced in calculation of reactor physic in this paper. Burnup calculation is completed by interpolation table of macroscopic cross section vs burnup, interpolated method and solving diffusion equation. The calculated result compared with shearon Harri s's result is satisfied. The method has characteristic of use friendly, less calculated time and occuracy demand. Now it is used in the practical calculation of reactor physic. A effective tool is provided for engineering design.