Experimental studies of large conventional LMFBR cores at ZPPR

Results of a critical experiment program for 700 MW(e) LMFBRs are reviewed. Both a clean bench-mark assembly and one simulating a power reactor design were constructed. Experiments discussed include reaction rate distributions and ratios, control rod worths and interactions, and sodium coefficients. Analysis of these experiments with ENDF/B Version IV cross sections is reported. The comparison between calculated and measured parameters is not too different in these cores than in the 350 MW(e) assemblies. An exception is that the radial fission rate is calculated up to 3% too high at the edge of the inner core relative to the core center