Coupled Neutronic Thermal Fluid Dynamic Modelling of a Very High Temperature Reactor
Author(s)
Tollit, Brendan S.
Type
Thesis
Abstract
The Very High Temperature Reactor (VHTR) is designed to push the boundaries
and capabilities of existing High Temperature Gas Reactor technology
to higher levels, challenging the desired inherent and passive safety features.
To ascertain the viability of the design requires a detailed understanding of
the complex multiphysics within the reactor core and the associated energy
removal system. Due to the scale of the calculation computational numerical
models are utilised. During a transient the greatest challenge to inherent
and passive safety design features will occur. To understand the core dynamics
during these off normal conditions requires the use and development
of coupled radiation transport thermal hydraulic codes.
In this thesis the coupled radiation transport computational multiphase fluid dynamic FETCH model is applied to a generic block type VHTR.
The purpose of this research is twofold. First to analyse the suitability of
the FETCH model to be capable of capturing the physics inherent within
the generic VHTR of interest. Secondly to analyse the suitability of the
generic VHTR to operate within certain key safety constraints of interest. A
necessary component of this research was to provide evidence to support the
reliability and credibility of model solutions through the use of a continuous
verification and validation automated framework.
Also this PhD thesis includes the development and analysis of a Sub Grid
Scale finite element methodology applied in the context of the multigroup
neutron diffusion equations. The method was found to be superior to standard
Continuous Galerkin finite element methods but suffered from stability
issues associated with low, or zero, absorption coefficient terms.
and capabilities of existing High Temperature Gas Reactor technology
to higher levels, challenging the desired inherent and passive safety features.
To ascertain the viability of the design requires a detailed understanding of
the complex multiphysics within the reactor core and the associated energy
removal system. Due to the scale of the calculation computational numerical
models are utilised. During a transient the greatest challenge to inherent
and passive safety design features will occur. To understand the core dynamics
during these off normal conditions requires the use and development
of coupled radiation transport thermal hydraulic codes.
In this thesis the coupled radiation transport computational multiphase fluid dynamic FETCH model is applied to a generic block type VHTR.
The purpose of this research is twofold. First to analyse the suitability of
the FETCH model to be capable of capturing the physics inherent within
the generic VHTR of interest. Secondly to analyse the suitability of the
generic VHTR to operate within certain key safety constraints of interest. A
necessary component of this research was to provide evidence to support the
reliability and credibility of model solutions through the use of a continuous
verification and validation automated framework.
Also this PhD thesis includes the development and analysis of a Sub Grid
Scale finite element methodology applied in the context of the multigroup
neutron diffusion equations. The method was found to be superior to standard
Continuous Galerkin finite element methods but suffered from stability
issues associated with low, or zero, absorption coefficient terms.
Date Issued
2010-12
Date Awarded
2011-02
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Pain, Christopher
Goddard, Tony
Creator
Tollit, Brendan S.
Publisher Department
Earth Science and Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)