The scattering kernel data for 7LiH 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 αm(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 αm(T)=C Fv(H)1.6 T−1.65 where Fv(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±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.
Generation of neutronic thermal data in support of space nuclear propulsion
10th SymposiumùSpace Nuclear Power and Propulsion ; 1993 ; Albuquerque, NM, USA
AIP Conference Proceedings ; 271 , 2 ; 965-971
1993-01-15
7 pages
Conference paper
Electronic Resource
English
MODERATORS , LITHIUM HYDRIDES , TEMPERATURE COEFFICIENT , SHIELDS , DESIGN , NEUTRONS , TEMPERATURE RANGE 0013−0065 K , SPACE PROPULSION REACTORS , LITHIUM 7 , CROSS SECTIONS , TEMPERATURE RANGE 0273−0400 K , REACTIVITY , DEBYE−WALLER FACTOR , TEMPERATURE RANGE 0065−0273 K , TEMPERATURE RANGE 0400−1000 K , TEMPERATURE DEPENDENCE
Generation of Neutronic Thermal Data in Support of Space Nuclear Propulsion
British Library Conference Proceedings | 1993
|American Institute of Physics | 1993
|British Library Conference Proceedings | 1993
|Neutronic feasibility of a low enriched fast spectrum nuclear thermal propulsion engine
TIBKAT | 2020
|