Subcritical limits for special fissile actinides
Critical masses and subcritical mass limits in oxide-water mixtures were calculated for actinide nuclides other than /sup 233/U, /sup 235/U, and /sup 239/Pu that have an odd number of neutrons in the nucleus: S/sub n/ transport theory was used together with cross sections, drawn from the GLASS multigroup library, developed to provide accurate forecasts of actinide production at Savannah River. The subcritical limits are 201 g for /sup 241/Pu, 13 g for /sup 242//sup m/Am, 90 g for /sup 243/Cm, 30 g for /sup 245/Cm, 900 g for /sup 247/Cm, 10 g for /sup 249/Cf, and 5 g for /sup 251/Cf. Association of /sup 241/Pu with an equal mass of /sup 240/Pu increases the /sup 241/Pu limit to a value greater than that for pure /sup 239/Pu. Association of /sup 242//sup m/Am with /sup 241/Am increases the limit for the mixture to that for dry, theoretical density AmO/sub 2/ at isotopic concentrations of /sup 242//sup m/Am less than approx. 6%. Association of /sup 245/Cm with /sup 244/Cm increases the limit according to the formula 30 + 0.3 /sup 244/Cm//sup 245/Cm up to the limit for dry CmO/sub 2/. A limiting mass of 8.15 kg for plutonium containing at least 67% /sup 238/Pu as oxide was calculated that applies (provided /sup 240/Pu exceeds /sup 241/Pu) with no limit on moderation. 1 figure, 5 tables.
- Research Organization:
- Savannah River Lab., Aiken, SC
- OSTI ID:
- 7052095
- Journal Information:
- Nucl. Technol.; (United States), Journal Name: Nucl. Technol.; (United States) Vol. 48:2; ISSN NUTYB
- Country of Publication:
- United States
- Language:
- English
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
AMERICIUM 242
AMERICIUM ISOTOPES
AQUEOUS SOLUTIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALIFORNIUM 249
CALIFORNIUM 251
CALIFORNIUM ISOTOPES
CRITICAL MASS
CURIUM 243
CURIUM 245
CURIUM 247
CURIUM ISOTOPES
DATA
DISPERSIONS
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FISSILE MATERIALS
FISSIONABLE MATERIALS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INFORMATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MASS
MATERIALS
MIXTURES
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PLUTONIUM 241
PLUTONIUM ISOTOPES
RADIOISOTOPES
SOLUTIONS
SUBCRITICALITY
THEORETICAL DATA
YEARS LIVING RADIOISOTOPES