Analysis of waste matrix material experiments mixed with highly enriched uranium on the thermal energy region

Conference · Sat Jul 01 04:00:00 EDT 2006

OSTI ID:22039622

Loaiza, D; Sanchez, R ^[1]

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1. MS J562, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

The basic characteristics of waste materials such as silicon dioxide, aluminum and iron fueled with highly enriched uranium and moderated and reflected by polyethylene were investigated. These critical mass experiments were performed at the Los Alamos Criticality Experiments Facility (LACEF) on the Planet critical assembly. The primary intention of these experiments is to provide supplementary data that can be used to validate and improve criticality data for the Yucca Mountain and the Hanford Storage Waste Tanks Projects. The secondary intention of these experiments is to reduce the H/U ratio and increase the waste material/U ratio from previously published experiments. These experiments were designed to supply data for interlaced waste material/Fuel/Moderator systems on the thermal region. The experiments contained silicon dioxide (SiO{sub 2}), aluminum (Al) and iron (Fe) mixed with 93.23% enriched uranium and moderated and reflected by polyethylene. A base case experiment was also performed with polyethylene-only. This analysis systematically examines uncertainties associated with the critical experiments as they affect the calculated multiplication factor. The systematic analysis is separated into uncertainties due to mass measurements, uncertainties due to fabrication and uncertainties due to composition. Each type of uncertainty is analyzed individually and a total combined uncertainty is derived. The SiO{sub 2}-HEU experiment had a measured k{sub eff} of 0.993, the Al-HEU experiment had a measured k{sub eff} of 0.990, the Fe-HEU had a measured k{sub eff} of 1.000 and the polyethylene-HEU had a measured k{sub eff} of 1.0025. The calculated k{sub eff} values tend to agree well with the experimental values. The sensitivity analysis of these critical experiments yielded a total combined uncertainty on the measured k{sub eff} of {+-}0.0024 for SiO{sub 2}, of {+-}0.0028 for Al, of {+-}0.0026 for Fe, of {+-}0.0020 for polyethylene. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22039622
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
ALUMINIUM
CRITICAL MASS
EXPERIMENTAL DATA
HIGHLY ENRICHED URANIUM
IRON
MATRIX MATERIALS
MULTIPLICATION FACTORS
POLYETHYLENES
RADIOACTIVE WASTE STORAGE
SENSITIVITY ANALYSIS
SILICON OXIDES
THERMAL NEUTRONS
YUCCA MOUNTAIN
ZERO POWER REACTORS