The computer simulation of the physics characters of pebble bed reactor

In order to research the physics characters of pebble bed HTGR, a complete computer simulation method and a correspondent physical computation program system have been developed. The special features of the method are as follows: the double heterogeneity of a fuel element with coated particles grain structure and the motion behaviour of a fuel ball are considered; the complex fuel manage in pile and out pile can be treated; the top cavity for loading the fuel pebbles is considered; the buckling feedback in the spectral calculation is introduced; the direct coupling between physics and thermal hydraulics is made. The method and code have been used in HTR-10 physics design