SPECTRAL SHIFT CONTROL REACTOR — BASIC PHYSICS PROGRAM — EXPONENTIAL EXPERIMENTS ON LATTICES MODERATED BY D2O-H2O MIXTURES

摘要

Summarized here are the results of exponential experiments per-formed under the Spectral Shift Control Reactor (SSCR) Basic Physics Program. The material buckling and cadmium ratio of U-235 were measured at room temperature in rod lattices moderated by D20-H20 mixtures in which the non-moderator-to-moderator volume ratio was approximately 1.0. The two types of fuel studied were 93%-enriched U02-Th02 pellets (NTh/N25 = 15) clad in 0.308-inch OD aluminum tubes and 4%-enriched U02 swaged in 0.476-inch OD stainless-steel tubes. The results are shown in the following tabulation, where the measured cadmium ratio of thorium in the first lattice is 1.14 ± 0.0Z. Also given is design information on the Lynchburg Source Reactor (LSR), which was assembled and operated at 1000 watts to provide neutrons for these experiments.