Reactivity Worth of the Central Fuel Element in the Bulk Shielding Reactor-I

The reactivity worth of a plate-type fuel element at the center of a critical lattice of such elements has been experimentally determined by the pulsed-neutron method. This value has not been previously established because it is too large to be obtained by conventional inhour techniques. The value obtained for the Bulk Shielding Reactor-I Loading No. 78 was Δρ = 6.1 ± 0.5 dollars. Additional measurements of a configuration in which the central element was replaced by an element containing either one-half or three-quarters of a normal fuel element loading are discussed.