skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Generation of neutronic thermal data in support of space nuclear propulsion

Conference ·
OSTI ID:10157138

The scattering kernel data for {sup 7}LiH have been generated for the first time in the temperature range 50--1000 K. This is based on a phonon distribution function derived from both experimental data and theoretical calculations. A detailed study of the variation of the moderator temperature coefficient {alpha}{sub m}(T) with temperature, T, is carried out for a typical space nuclear reactor of the particle bed type. It is established that the moderator temperature coefficient due to chemical binding effects follows the relationship {alpha}{sub m}(T) = C F{sub v}(H){sup 1.6} where F{sub v}(H) is the volume fraction of bound solid hydrogen and C is a normalization constant which depends on the moderator capture thermal cross section. The value 1.65 is to be compared with 1.54 {plus_minus} 0.06 derived in a previous study where water scattering kernels are applied. For control and safety reasons, a minimization of this positive component temperature coefficient can be most effective by operating the moderator at high temperatures. Advantages of this approach are outlined. In addition, suggestions are made to render the overall temperature coefficient negative.

Research Organization:
Brookhaven National Lab., Upton, NY (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC02-76CH00016
OSTI ID:
10157138
Report Number(s):
BNL-48540; CONF-930103-37; ON: DE93013148
Resource Relation:
Conference: 10. symposium on space nuclear power and propulsion,Albuquerque, NM (United States),10-14 Jan 1993; Other Information: PBD: [1993]
Country of Publication:
United States
Language:
English