A series of two-group calculations has been made on the Oracle for the purpose of obtaining critical-mass and flux distribution data for various ORR core configurations. The 3G3R code of Bate, Einstein, and Kinney was used, together with the RSP code developed by Nelson. This made it possible to obtain results for the three-dimensional case. The results, which are presented graphically, are intended to serve as a guide for the design of experiments until such time as actual measurements are available. The calculations were performed for the "clean cold" case, and it should be realized that the presence in the core of experiments and of fission products built up during operation will materially alter the flux patterns found. It is believed that the critical-mass data are accurate to within 10%. Within the fuel region it is believed that the thermal-flux patterns are the also accurate to this degree. Comparison of the results with MTR critical experiments, however, indicates that the thermal flux in the reflector in the vicinity of the fuel-reflector interface may have been underestimated by a factor of as much as 1.3. It should also be recalled that in a two-group calculation the "fast flux" is often a …

From abstract: "A full-scale, always-safe, metal dissolver for Experimental Breeder Reactor fuel was designed, built, and installed for test operation. It was found that the dissolver operated satisfactorily, and feasible operating procedures were established for the dissolution of bare, or jacketed, EBR slugs. Minor modifications of the dissolver design have been required to accomodate [sic] a modified EBR slug, but it is believed that this will not significantly affect its operating characteristics."

Five uninsulated semipermanent freeze coils, series connected, can be frozen when submerged in 70 F water with a Freon-11 flow rate of 1.85 gpm at an inlet temperature of -40 F. The refrigeration unit of the HRT-CP is capable of delivering >3 gpm to a similar semipermanent freeze coil system located in Cell C. Therefore the number of F-11 risers required in Cell C of the HRT-CP can be minimized by series connecting this many semipermanent freeze coils where required.