Reactivity feedback mechanisms in aqueous fissile solutions

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Nuclear Science and Engineering; (United States)

DOI:https://doi.org/10.13182/NSE93-1· OSTI ID:6019677

Kornreich, D E ^[1]

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1. Univ. of Arizona, Tucson, AZ (United States). Dept. of Nuclear and Energy Engineering

Solutions of fissile materials are often encountered during spent-fuel reprocessing. To estimate the hazards from accidental criticalities in these solutions, models have been developed to understand better the dynamics involved. Accurate representation of reactivity feedback mechanisms is a crucial part of such models. Reactivity feedback from uniform volumetric solution expansion is studied. For faster transients, density redistribution may also occur because of a variation of nuclear energy as a function of position in the assembly. Neutronic spectral temperature reactivity effects are studied by creating temperature-dependent cross sections from ENDF/B-VI data. The volumetric and temperature reactivity feedback coefficients are determined for the CRAC, KEWB-5, SILENE, and SHEBA solution assemblies. Spectral temperature coefficients are also calculated for poisoned, unpoisoned, and reflected plutonium solutions. Feedback coefficients are seen to be functions of geometry and isotopic contents of the assemblies. Results for plutonium solutions agree with other calculations, which confirms the possibility of autocatalytic excursions in large, dilute solutions.

• OSTI ID: 6019677
• Journal Information: Nuclear Science and Engineering; (United States), Journal Name: Nuclear Science and Engineering; (United States) Vol. 115:1; ISSN NSENAO; ISSN 0029-5639
• Country of Publication: United States
• Language: English

Related Subjects

050400 -- Nuclear Fuels-- Feed Processing
050800* -- Nuclear Fuels-- Spent Fuels Reprocessing
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ACCIDENTS
ACTINIDES
AQUEOUS SOLUTIONS
CRITICALITY
DISPERSIONS
ELEMENTS
ENERGY SOURCES
FISSILE MATERIALS
FISSIONABLE MATERIALS
FUEL REPROCESSING PLANTS
FUELS
MATERIALS
MATHEMATICAL MODELS
METALS
MIXTURES
NUCLEAR FACILITIES
NUCLEAR FUELS
PLUTONIUM
REACTIVITY
REACTIVITY COEFFICIENTS
REACTOR MATERIALS
REPROCESSING
SAFETY
SEPARATION PROCESSES
SOLUTIONS
SPENT FUELS
TEMPERATURE COEFFICIENT
TRANSURANIUM ELEMENTS