NEUTRONIC INVESTIGATION OF A POWER-PLANT USING PEACEFUL NUCLEAR EXPLOSIVES

A neutron physics analysis of the modified PACER concept was conducted to assess the required liquid zone thickness of which the volume frac tion is 25% in the form of Li2BeF4 (Flibe) jets and 75% as void. These liquid jets surround a low-yield nuclear fusion explosive and protect the chamber walls. The neutronic calculations assumed a 30-m-radius u nderground spherical geometry cavity with a 1-cm-thick stainless steel liner attached to the excavated rock wall. Achievement of tritium bre eding ratios of 1.05 and 1.15 requires a Flibe thickness of 1.6 and 2. 0 m, respectively, which results in average energy densities of 24 900 and 19 085 J/g. Our calculations show that for a Flibe zone thickness >2.5 m, the activation of the steel linear and rock would be low enou gh after 30 yr of operation that the cavity would satisfy the U.S. Nuc lear Regulatory Commission's rules for ''shallow burial'' upon decommi ssioning, assuming other sources of radioactivity could be removed or qualified as well. This means that upon decommissioning, the site coul d essentially be abandoned, or the cavity could be used as a shallow b urial site for other qualified materials.