LEAKAGE OF NEUTRONS FROM BARE SUBCRITICAL PLUTONIUM SYSTEMS

Technical Report · Thu Dec 01 04:00:00 EST 1960

OSTI ID:4067884

Clark, B C; Carter, J L

Results are given of approximates calculations of the total leakage rate of fast and thermal neutrons from bare subcritical systems of plutonium in solution. These calculations are of use in assessing the possibility of monitoring this leakage for nuclear safety purposes. The calculations are based on a simple one-group model with slowing down, assuming pure Pu/sup 239/ as the fuel. Parameters in the model are adjusted to agree with the best available information on the critical volumes of such solutions. Corrections are made to estimate the effect of small amounts of Pu/sup 240/. The concentrations encountered in the calculations ranged from 25 g/l to 1000 g/l, corresponding to H/Pu atonnic ratios from 20 to 1000. The results for pure Pu/sup 239/ fuel can be summarized se follows: Both the fast and thermal leakages from systems of a given concentration are predicted to increase by about a factor of 10 as the volumes change from 0.5 to 0.9 of critical volume. For a fixed volume, the change in leakage with concentration change is a more complex function of concentration and volume. For the volumes considered, the leakage of fast neutrons from solution concentrations which are 0.9 that of critical range from 4 to 18 times the leakage from concentrations which are 0.5 that of critical. The corresponding thermal leakage ratios for each volume are about one-half as lange as the fast neutrons. The presence of Pu/sup 240/ decreases these ratios by an appreciable factor in some cases. (auth)

• Research Organization: General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
• DOE Contract Number: AT(45-1)-1350
• NSA Number: NSA-15-013576
• OSTI ID: 4067884
• Report Number(s): HW-67691
• Country of Publication: United States
• Language: English

Related Subjects

CRITICAL ASSEMBLIES
CRITICALITY
ENRICHMENT
FAST NEUTRONS
GROUP THEORY
LEAKS
MONITORING
NEUTRONS
PHYSICS
PLUTONIUM
PLUTONIUM 239
PLUTONIUM 240
SAFETY
SLOWDOWN
SOLUTIONS
THERMAL NEUTRONS
VOLUME