SPECTRAL SHIFT CONTROL REACTOR BASIC PHYSICS PROGRAM. Quarterly Technical Report No. 2, October-December 1960

Basic physics parameters are being determined for lattices of slightly enriched fuel in moderators consisting of D/sub 2/O--H/sub 2/O mixtures of different concentrations. The principal effort was devoted to procurement and erection of equipment and materials needed for the critical experiments with D/ sub 2/O in the moderator, the exponential experiments, the hot exponential experiments, and the neutron age experiments. The erection of these facilities and the D/sub 2/O handling system was completed and checked out. The fuel rod preparation was completed, and all necessary hazard evaluations and linense applications were submitted. Two critical experiments with 4%-enriched UO/sub 2/ fuel and H/sub 2/O moderator (one clean and one poisoned with boric acid) were completed. In these cores the critical mass, critical buckling, thermal disadvantage factor, and cadmium ratio of U/sup 235/ were measured and the data are reported. The BPG computer code, which will be used to analyze the experiments with D/sub 2/O in the moderator, was completed and checked out. The accuracy of the code was checked by computing a variety of H/sub 2/O and D/sub 2/ O moderated critical experiments and applicable neutron age measurements and comparing results with those obtained by other standard calculational methods. Calculations supporting the planning and design of the experiments also continued. (auth