Considerations of autocatalytic criticality of fissile materials in geologic repositories

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Nuclear Technology

OSTI ID:379832

Kastenberg, W E; Peterson, P F; Ahn, J ^[1]

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1. Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; and others

Potential routes to autocatalytic criticality in geologic repositories are systematically assessed. If highly enriched uranium (HEU) or {sup 239}Pu are transported and deposited in concentrations similar to natural uranium ore, in principle, criticality can occur. For some hypothesized critical configurations, removal of a small fraction of pore water provides a positive feedback mechanism that can lead to supercriticality. Rock heating and homogenization for these configurations can also significantly increase reactivity. At Yucca Mountain, it is highly unlikely that these configurations can occur; plutonium transport would occur primarily as colloids and deposit over short distances. HEU solute can move large distances in the Yucca Mountain setting; its ability to precipitate into critical configurations is unlikely because of a lack of active reducing agents. Appropriate engineering of the waste form and the repository can reduce any remaining probability of criticality.

• OSTI ID: 379832
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 3 Vol. 115; ISSN 0029-5450; ISSN NUTYBB
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
CRITICALITY
HIGH-LEVEL RADIOACTIVE WASTES
INTERSTITIAL WATER
PLUTONIUM 239
RADIOACTIVE WASTE FACILITIES
RADIONUCLIDE MIGRATION
SAFETY ANALYSIS
UNDERGROUND DISPOSAL
YUCCA MOUNTAIN