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Title: Optimizing Neutron Thermal Scattering Effects in very High Temperature Reactors. Final Report

Technical Report ·
DOI:https://doi.org/10.2172/1157573· OSTI ID:1157573
 [1];  [2]
  1. North Carolina State Univ., Raleigh, NC (United States). Dept. of Nuclear Engineering
  2. Idaho National Lab. (INL), Idaho Falls, ID (United States)

This project aims to develop a holistic understanding of the phenomenon of neutron thermalization in the VHTR. Neutron thermalization is dependent on the type and structure of the moderating material. The fact that the moderator (and reflector) in the VHTR is a solid material will introduce new and interesting considerations that do not apply in other (e.g. light water) reactors. The moderator structure is expected to undergo radiation induced changes as the irradiation (or burnup) history progresses. In this case, the induced changes in structure will have a direct impact on many properties including the neutronic behavior. This can be easily anticipated if one recognizes the dependence of neutron thermalization on the scattering law of the moderator. For the pebble bed reactor, it is anticipated that the moderating behavior can be tailored, e.g. using moderators that consist of composite materials, which could allow improved optimization of the moderator-to-fuel ratio.

Research Organization:
North Carolina State Univ., Raleigh, NC (United States); Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE). Nuclear Energy University Programs (NEUP)
DOE Contract Number:
AC07-05ID14517
OSTI ID:
1157573
Report Number(s):
DOE/NEUP-09-822; TRN: US1500394
Country of Publication:
United States
Language:
English