Nuclear graphite is the specific form of graphite most commonly found in reactor applications including advanced reactor moderators, criticality safety, and reactor reflectors. Nuclear graphite has a density which ranges from 1.6-1.8 g/cm3 where ideal crystalline graphite has a density of 2.25 g/cm3. This difference in density has been represented using a porous graphite model to capture the effects of this structure and density change to the cross sections. Porous graphite models were created using molecular dynamics (MD) simulations. From the generated velocity autocorrelation function (VACF), the corresponding density of states (DOS) was derived and used in FLASSH 1.0 to calculate the thermal scattering law (TSL). Three porous models have been used to create 10%, 20% and 30% porous nuclear graphite TSLs corresponding to graphite densities of approximately 1.6, 1.7, and 1.8 g/cm3.
Publications
Inelastic Thermal Neutron Scattering Cross Sections for Reactor-grade Graphite
Thermal Neutron Scattering Law Calculations using Ab Initio Molecular Dynamics
High Temperature Graphite Simulations using Molecular Dynamics
Development of the Thermal Neutron Scattering Cross Sections of Graphitic Systems using Classical Molecular Dynamics Simulations
Benchmark of Neutron Thermalization in Graphite Using a Pulsed Slowing-Down-Time Experiment
Impact of the Graphite Thermal Scattering Law on Criticality Calculations
Positron Characterization of Neutron Irradiated Reactor-grade Graphite
Inelastic Neutron Scattering Analysis of Reactor-grade Graphite
Benchmarking Thermal Neutron Scattering in Graphite
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