Abstract
The research described below addresses the storage and disposal of radioactive wastes, arising
mainly from the nuclear power industry. The United Kingdom built the world’s first civil
reactor and nuclear power currently provides ~15% of the country’s electricity. Generating
capacity has decreased in recent years but concerns over energy security have prompted plans
to drastically increase production in the coming decades via investment in both large (1.6 GW)
and small (<500 MW) scale plants; the first of these are now under construction (Hinckley C)
or at the advanced planning stage (Sizewell C).
Over the years, opponents of new nuclear build have focussed on the industry’s poor record of
waste management and accountability. Operations over seven decades have led to a highly
variable inventory of accumulated wastes together with legacy contaminated infrastructure
requiring decommissioning. The cost of remediating the UK’s civil nuclear sites has been
estimated at £132 billion, the highest proportion of which is associated with Sellafield in
Cumbria and its role in developing the independent nuclear deterrent. Indeed, simply managing
this large and complex site, which no longer produces electricity or reprocesses fuel, requires
approximately £3 billion per annum. Similar challenges are faced by other countries, though
few on the scale of the UK. Those that do include the United States, the Russian Federation
and France, owing to a combination of their large civil and defence programmes.
All forms of commercial energy generation produce waste and the nuclear industry is not
unique in this regard; however, the extent to which other industries, notably the production and
combustion of fossil fuels and exploitation of mineral resources, give rise to substantial
volumes of radioactive waste is much less widely appreciated. Indeed, the volumes created
each year dwarf those produced by the nuclear sector. As with nuclear wastes, they require
careful handling and disposal to limit public exposures and their impact on the wider
environment. ‘Cradle to grave’ risk assessments and new radioactive waste treatment facilities
devised by the author have underpinned a number of successful land remediation programmes
and contributed to the creation of a sustainable village in Cornwall.
The author has been closely involved in assessing the radiological risks posed by both
nuclear and industrial radioactive wastes over the past 40 years. Throughout this time he has
sought to improve our scientific understanding of the key processes involved in radionuclide
release from containment systems and their migration through natural and man-made
barriers. Regulatory requirements governing future disposals stipulate annual individual risk
targets for which predictive models are used to extrapolate over long timescales. Evidence
in support of these models is then drawn from a wide range of disciplines, with chemistry
playing a central role, allowing more robust and defensible models of repository evolution.
Advances in analytical techniques, experimental procedures and computational methods
developed to reduce uncertainty in predictions are highlighted, focussing on three key areas:
waste-form degradation, performance of (primarily) cementitious barriers and interactions
with the host rock. Evidence in support of their impact on industry, regulators, national
governments, and supranational bodies, such as the International Atomic Energy Agency
(IAEA), OECD Nuclear Energy Agency (NEA) and the European Commission (EC) is
provided. These include increased focus and investment in fundamental nuclear research and
optimised protocols for radioactive waste disposition, thereby extending the operational
lifetime of existing facilities.