Critical Experiments with Strong Neutron Absorbers Heterogeneously Distributed Throughout Uranyl Nitrate Solution

Conference · Mon Sep 09 04:00:00 EDT 1991

OSTI ID:5720648

Rothe, R. E. ^[1]

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1. EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant

Several critical experiments were performed for a number of strong neutron absorbers periodically distributed throughout a tank filled with high-concentration fissile solution. These experiments served as a pilot study for a novel means of storing fissile solutions at a nuclear production plant handling such solutions. The configuration also approximates one commonly used method (Raschig rings) of assuring criticality safety in such plants, Still, the configuration is heterogeneous, and so, easily susceptible to modeling with modern computer codes. The fissile solution was uranyl nitrate at about 363 gU/liter with the uranium enriched to 93.2% U²³⁵. One important neutron absorber studied consisted of borosilicate glass rods, containing the same 12.5% boron oxide found in Raschig rings used throughout the industry. Another consisted of rubber sheet containing 0.1 mg/mm² boron (as B₄C) glued to thin-walled steel tubing. Cadmium sheet metal (1.6 mm thick) wrapped around steel rods formed yet another absorber; and solid polyvinyl chloride rods were also studied. Four loose powders packed into paper tubes completed the list of absorbers: cadmium oxide, anhydrous boric acid, sodium tetraborate pentahydrate, and a very inexpensive mixture of two common minerals-colmanite (calcium borate) and ulexite (sodium-calcium borate). The spacing between tubes containing each absorber was varied widely in both square and triangular patterns,

• Research Organization: EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC34-90DP62349
• OSTI ID: 5720648
• Report Number(s): RFP-4455; CONF-910993--2; ON: DE91014228
• Country of Publication: United States
• Language: English

Related Subjects

050900* -- Nuclear Fuels-- Transport
Handling
& Storage
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE COMPOUNDS
ACTINIDES
Absorbers
BORIC ACID
BORON CARBIDES
BORON COMPOUNDS
BORON OXIDES
BOROSILICATE GLASS
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COLUMN PACKING
CRITICALITY
Critical Experiments
ELEMENTS
ENRICHED URANIUM
GLASS
HYDROGEN COMPOUNDS
High-Concentration Fissile Solution
INORGANIC ACIDS
ISOTOPE ENRICHED MATERIALS
MATERIALS
METALS
MINERALS
NEUTRON ABSORBERS
NITRATES
NITROGEN COMPOUNDS
Nuclear Criticality Safety Program (NCSP)
OXIDES
OXYGEN COMPOUNDS
PACKINGS
Raschig Rings
Strong Neutron
TESTING
URANIUM
URANIUM COMPOUNDS
URANYL COMPOUNDS
URANYL NITRATES