Extrapolated experimental critical parameters of unreflected and steel-reflected massive enriched uranium metal spherical and hemispherical assemblies

Technical Report · Mon Dec 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/658339· OSTI ID:658339

Rothe, R E

Sixty-nine critical configurations of up to 186 kg of uranium are reported from very early experiments (1960s) performed at the Rocky Flats Critical Mass Laboratory near Denver, Colorado. Enriched (93%) uranium metal spherical and hemispherical configurations were studied. All were thick-walled shells except for two solid hemispheres. Experiments were essentially unreflected; or they included central and/or external regions of mild steel. No liquids were involved. Critical parameters are derived from extrapolations beyond subcritical data. Extrapolations, rather than more precise interpolations between slightly supercritical and slightly subcritical configurations, were necessary because experiments involved manually assembled configurations. Many extrapolations were quite long; but the general lack of curvature in the subcritical region lends credibility to their validity. In addition to delayed critical parameters, a procedure is offered which might permit the determination of prompt critical parameters as well for the same cases. This conjectured procedure is not based on any strong physical arguments.

• Research Organization: Lockheed Idaho Technologies Co., Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC07-94ID13223
• OSTI ID: 658339
• Report Number(s): INEEL/EXT--97-01401; ON: DE98052564; BR: WAS4AA197
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
22 GENERAL STUDIES OF NUCLEAR REACTORS
BENCHMARKS
CRITICAL MASS
CRITICALITY
HIGHLY ENRICHED URANIUM
NEUTRON REFLECTORS
NSF-RFP REACTOR
Nuclear Criticality Safety Program (NCSP)
ROCKY FLATS PLANT
SAFETY
SPHERICAL CONFIGURATION
STEELS