The safety and regulatory challenges associated with the geological disposal of the UK’s higher activity radioactive waste in England and Wales
File(s)
Author(s)
Marsh, Ashley Ian
Type
Thesis or dissertation
Abstract
The UK’s higher activity waste (HAW) is set to be disposed of in a geological disposal facility
(GDF). International consensus is that a GDF provides the most comprehensive means of
isolating and containing HAW and its harmful radionuclides, with nations at different stages in
their implementation of geological disposal. The maturity of some nations’ disposal programmes
(e.g. Finland, Sweden) ensures a regulatory framework for their GDF is well established. The
UK is currently engaged in a GDF site selection process, as such it is necessary that the
regulatory framework for the geological disposal of its radioactive waste be fully established
to meet the unique challenges posed by this first-of-a-kind facility for the UK. The reduced
hazard potential and unique features of the GDF may mean the existing framework applied
to UK nuclear installations does not proportionately meet the requirements for maintaining
worker and public safety and the protection of the environment. The purpose of the work
presented in this thesis was to investigate the safety and regulatory challenges associated with the
geological disposal of UK HAW. This began by building an understanding of the fundamentals
of radioactive waste and geological disposal in the UK and the risks associated with geological
disposal. Having investigated the performance of proposed engineered barrier materials for
the GDF, a simplified, 1-dimensional risk assessment model was developed for the disposal of
spent nuclear fuel (SNF) in a hypothetical geological setting. The model was verified against
data provided by Radioactive Waste Management Ltd (RWM Ltd), the UK’s GDF delivery
body, and utilised to conduct sensitivity studies, for the purpose of identify factors which could
significantly impact on the radiological risk to the public due to the disposal of Spent Nuclear
Fuel. Where significant, it was considered whether this might impact on the nature of the
regulatory oversight required. The framework applied to nuclear installations in the regulation
of nuclear safety, security, environmental protection and safeguards was mapped and analysed
for its applicability to GDF-specific challenges. International experience in the regulation of
GDFs was drawn upon in order to identify common features. Stakeholder opinion, including
members of industry, regulators, waste producers and local interest groups, was also sought, in
order to highlight their views on the applicability of the current system of nuclear site licensing
to a GDF. This work culminated with a proposal for a regulatory framework, which aims to
proportionately address the unique challenges associated with geological disposal.
(GDF). International consensus is that a GDF provides the most comprehensive means of
isolating and containing HAW and its harmful radionuclides, with nations at different stages in
their implementation of geological disposal. The maturity of some nations’ disposal programmes
(e.g. Finland, Sweden) ensures a regulatory framework for their GDF is well established. The
UK is currently engaged in a GDF site selection process, as such it is necessary that the
regulatory framework for the geological disposal of its radioactive waste be fully established
to meet the unique challenges posed by this first-of-a-kind facility for the UK. The reduced
hazard potential and unique features of the GDF may mean the existing framework applied
to UK nuclear installations does not proportionately meet the requirements for maintaining
worker and public safety and the protection of the environment. The purpose of the work
presented in this thesis was to investigate the safety and regulatory challenges associated with the
geological disposal of UK HAW. This began by building an understanding of the fundamentals
of radioactive waste and geological disposal in the UK and the risks associated with geological
disposal. Having investigated the performance of proposed engineered barrier materials for
the GDF, a simplified, 1-dimensional risk assessment model was developed for the disposal of
spent nuclear fuel (SNF) in a hypothetical geological setting. The model was verified against
data provided by Radioactive Waste Management Ltd (RWM Ltd), the UK’s GDF delivery
body, and utilised to conduct sensitivity studies, for the purpose of identify factors which could
significantly impact on the radiological risk to the public due to the disposal of Spent Nuclear
Fuel. Where significant, it was considered whether this might impact on the nature of the
regulatory oversight required. The framework applied to nuclear installations in the regulation
of nuclear safety, security, environmental protection and safeguards was mapped and analysed
for its applicability to GDF-specific challenges. International experience in the regulation of
GDFs was drawn upon in order to identify common features. Stakeholder opinion, including
members of industry, regulators, waste producers and local interest groups, was also sought, in
order to highlight their views on the applicability of the current system of nuclear site licensing
to a GDF. This work culminated with a proposal for a regulatory framework, which aims to
proportionately address the unique challenges associated with geological disposal.
Version
Open Access
Date Issued
2022-06
Date Awarded
2023-02
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Williams OBE, Laurence G
Lawrence, James A
Sponsor
Engineering and Physical Sciences Research Council
Radioactive Waste Management Ltd (Firm)
Grant Number
EP/R512540/1
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)