Spent Fuel Criticality Benchmark Experiments

Scaglione, J.M.

United States. Department of Energy. Yucca Mountain Project Office.

关键词: Criticality;    Energy Range;    Energy Spectra;    Distribution Functions;    Neutron Flux;   

DOI  :  10.2172/805601
RP-ID  :  NONE
RP-ID  :  AC08-01RW12101
RP-ID  :  805601

美国|英语

来源: UNT Digital Library

【 摘 要 】

Characteristics between commercial spent fuel waste packages (WP), Laboratory Critical Experiments (LCEs), and commercial reactor critical (CRC) evaluations are compared in this work. Emphasis is placed upon comparisons of CRC benchmark results and the relative neutron flux spectra in each system. Benchmark evaluations were performed for four different pressurized water reactors using four different sets of isotopes. As expected, as the number of fission products used to represent the burned fuel inventory approached reality, the closer to unity k{sub eff} became. Examination of material and geometry characteristics indicate several fundamental similarities between the WP and CRC systems. In addition, spectral evaluations were performed on a representative pressurized water reactor CRC, a 21-assembly area of the core modeled in a potential WP configuration, and three LCEs considered applicable benchmarks for storage packages. Fission and absorption reaction spectra as well as relative neutron flux spectra are generated and compared for each system. The energy dependent reaction rates are the product of the neutron flux spectrum and the energy dependent total macroscopic cross section. With constant source distribution functions, and the total macroscopic cross sections for the fuel region in the CRCs and WP being composed of nearly the same isotopics, the resulting relative flux spectra in the CRCs and WP are very nearly the same. Differences in the relative neutron flux spectra between WPs and CRCs are evident in the thermal energy range as expected. However, the relative energy distribution of the absorption, fission, and scattering reaction rates in both the CRCs and the WP are essentially the same.