Critical Concentration Of Uranium Solution
The experiments with U(37)O{sub 2}F{sub 2} aqueous solution followed the series of experiments with {sup 233}UO{sub 2}(NO{sub 3}){sub 2} and U(93)O{sub 2}(NO{sub 3}){sub 2} solutions in the 69.2-cm-diam sphere. The critical concentrations of {sup 233}U and {sup 235}U were used to evaluate the ratio of {ovr {eta}{sigma}{sub a}}(233)/{ovr {eta}{sigma}{sub a}}(235) some years ago when the accepted value of {ovr {eta}}(233) was questioned. The purpose of the experiment reported here was to measure the increase in {sup 235}U critical concentration and, hence, the increase in critical mass due to the increase in the {sup 238}U content in the 69.2-cm-diam sphere. The U(37)O{sub 2}F{sub 2} concentration in an aqueous solution was adjusted to that when an aluminum spherical vessel was completely filled and the multiplication factor was greater than unity and the excess reactivity was measured by means of a positive reactor period. The critical conditions are summarized in Table 1. The critical conditions for U(93)O{sub 2}(NO{sub 3}){sub 2} solution in the same sphere are also given for comparison and there is only a small difference in the critical {sup 235}U density or mass. In these well moderated solutions there is only a small amount of neutron absorption in {sup 238}U. A comparison of the calculated multiplication factors using the DSN and ANISN transport codes with different Hansen-Roach 16-group cross-section sets is presented in Table 2. The calculated value of 1.0005 is to be compared to the experimental value of 1.0011.
- Research Organization:
- Oak Ridge Y-12 Plant (Y-12), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP)
- DOE Contract Number:
- AC05-00OR22800
- OSTI ID:
- 1021430
- Report Number(s):
- Y/DR-118
- Country of Publication:
- United States
- Language:
- English
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