Accession Number : AD0284016

Title :   THE NUCLEAR EFFECT OF USING LITHIUM HYDRIDE AS THE PROPELLANT IN A NUCLEAR ROCKET REACTOR

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : BARTLETT,ROBERT OWEN

Report Date : MAY 1962

Pagination or Media Count : 1

Abstract : The nuclear effect of using LiH, containing Li of various isotopic percentages of Li-6 and Li-7, as a nuclear rocket propellant was investigated by applying a modified two-group neutron diffusion theory for a side-reflected cylindrical reactor to a model reactor composed of a core containing a homogeneous mixture of U-235, U-238, C-12, and LiH; and an infinite Beryllium reflector. Numerous reactor problems were solved on a digital computer for the critical mass of the reactor containing masses of LiH from 0 to 100 Kg with Li-7 enrichments from 90 to 100% for nuclear operating temperatures of 5330, 4280, and 3420 F. The nuclear effect of using LiH is that of a poison. This effect is directly related to the amount of the Li-6 isotope present in the Li. For the temperatures considered, the critical mass requirement of the reactor increases linearly with the addition of LiH such that the slope of this increase is linearly related to the isotopic percentage of the Li-6 present in the lithium. Isotopic percentages of Li-6 greater than 1% cause an excessive penalty to be paid in terms of fuel loading in order to achieve criticality. The feasibility of using LiH as the propellant appears remote without the removal of at least all but 1% of the Li-6 isotope from the Li. (Author)

Descriptors :   *LITHIUM COMPOUNDS, *NUCLEAR PROPULSION, FEASIBILITY STUDIES, HYDRIDES, MATHEMATICAL ANALYSIS, REACTOR FUELS, THEORY, URANIUM

Distribution Statement : APPROVED FOR PUBLIC RELEASE