CONTROL AUGMENTATION CRITICAL EXPERIMENTS

Critical experiments are reported for clumped heterogeneous light water moderated lattices using 3 wt% enriched UO/sub 2/ fuel clad with stainless steel. Reactivity worth utilizing water height and pulsed neutron-techniques, temperature and void coefficients, flux and power distributions, andd spectral indicator activations were measured for a wide range of configurations. These configurations were typical of boiling water reactor lattices and included assemblies with black and gray absorbing slabs and control rod cruciforms. Differential reactivity and spectrum effects were investigated for various slab, cruciform and void tube perturbations in these experiments. The resonance spectral indicator method was used in particular to study the spatial variation of the neutron spectrum and density in a typical boiling water reactor lattice. The observed spatial neutron spectrum variations show that this is a very useful technique. (auth)