American National Standard ANSI/ANS-8. 15-1981: Criticality Control of Special Actinide Elements

Conference · Sun Nov 10 04:00:00 EST 1991 · Transactions of the American Nuclear Society

OSTI ID:7273173

The American National Standard, Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors, ANSI/ANS-8.1-1983, provides single-parameter limits for operations with ²³³U, ²³⁵U, and ²³⁹Pu. The principal interest in criticality safety is in these isotopes of uranium and plutonium since they are the most abundant, but there are also other isotopes of these nuclides and other elements within the actinide group that are capable of supporting a chain reaction and that may be encountered in sufficient quantities to cause concern. The American National Standard, Nuclear Criticality Control of Special Actinide Elements, (ANSI/ANS 8.15-1981), presents subcritical mass limits for a number of these actinide nuclides, both fissile and nonfissile isotopes. A key factor for estimating the critical mass of a specific nuclide is whether the nuclide contains an odd or even number of neutrons. Subcritical limits are shown for nonfissile actinide nuclides. These limits are applicable if the effect of neutron return from nearby materials (fissionable and other) is no greater than the effect of the reflector indicated. Subcritical limits for fissile nuclides in aqueous solutions and slurries are also give. The standard includes several multiparameter limits in which mixtures of fissile and nonfissile nuclides allow larger subcritical limits for the fissile nuclide when mixed with a non-fissile nuclide than for the fissile nuclide alone.

• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• OSTI ID: 7273173
• Report Number(s): CONF-911107--
• Conference Information: Journal Name: Transactions of the American Nuclear Society Journal Volume: 63
• Country of Publication: United States
• Language: English

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ELEMENTS
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Nuclear Criticality Safety Program (NCSP)
ODD-EVEN NUCLEI
PLUTONIUM 239
PLUTONIUM 241
PLUTONIUM ISOTOPES
RADIOISOTOPES
SAFETY STANDARDS
SPECTRA
SPONTANEOUS FISSION RADIOISOTOPES
STANDARDS
SUBCRITICALITY
URANIUM 233
URANIUM 235
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