By: Stanley E. Turner

Publisher: Nuclear Science and Engineering

Year: 1981

Abstract: he AMPX-KENO computer code package is commonly used to evaluate criticality in high-density spent fuel storage rack designs. Consequently, it is important to know the reliability that can be placed on such calculations and whether or not the results are con-servative. Recent critical experiments by the Babcock & Wilcox Company (B&W) provide data on configurations with thin absorbers containing boron that are more near(v representative of poisoned spent feel storage rack designs than were earlier critical experiments.

A series of AMPX-KENO calculations has been made on selected critical experiments and the results compared with similar analyses reported in the literature by the Oak Ridge National Laboratory and B&W. Within the normal statistical variation of KENO calculations, results confirm that there is no apparent difference in the versions of AMPX-KENO and the 123-group GAM-THERMOS libraries used at three different computer installations.

Evaluation of the calculational results provides evidence for a statistically significant trend toward overprediction of reactivity with increasing reactivity worth of thin plates f boron-containing material. Similarly, statistical analyses reveal a trend toward under-prediction of reactivity with increasing water-gap spacing between fuel assemblies.

Statistical analyses in support of these contentions are provided, and additional critical experiments with boron absorbers of higher reactivity worth are recommended.

Citation: Turner, S. “Evaluation of AMPX-KENO Benchmark Calculations for High-Density Spent Fuel Storage Racks.” Nuclear Science and Engineering, 1981.