A SUBGROUP METHOD BASED ON THE EQUIVALENT DANCOFF-FACTOR CELL TECHNIQUE COMPARED WITH THE FINE-STRUCTURE METHOD IN APOLLO3®

We compare a newly implemented subgroup method, which is based on the equivalent Dancoff-factor cell technique, with fine structure method in APOLLO3®. The new obtains precise reaction rates and consequently predicting multipli-cation factor. It can reduce time self-shielding calculation by factor of 38 compared multi-cell approximation PWR Gd-UOX assembly calculation. larger errors reac-tion than but error compensation sometimes leads to small multiplication factors. This work demonstrates precision efficiency method.