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| Fig. 1: Ariel View of Sellafield, Cumbria. (Source: Wikimedia Commons) |
How to deal with with Britain's radioactive waste has been a controversial issue over the last few years. While there are many sources of radioactivity, we are mostly concerned here with higher activity radioactive waste. Higher activity radioactive wastes are produced as a result of the generation of electricity in nuclear power stations, from the associated production and reprocessing of the nuclear fuel, from the use of radioactive materials in industry, medicine and research, and from defense-related nuclear programs. [1]
As a pioneer of nuclear technology, the UK has accumulated a legacy of higher activity radioactive waste and material. According to the Nuclear Decommissioning Authority, the total amount of radioactive waste currently held in stores at 1 April 2016 and forecast in the future up to 2125 would occupy a volume of about 4.77 million cubic meters. [2] Some of this has already arisen as waste and is being stored on an interim basis at nuclear sites across the UK. The rest will arise as existing facilities reach the end of their lifetime and are decommissioned and cleaned up, and through the operation and decommissioning of any new nuclear power stations. [2]
In order to safeguard human health and minimize the impact on the environment, radioactive waste needs to be contained and managed.
The Sellafield reprocessing plant, in Cumbria, England, currently handles nearly all the radioactive waste generated by the UK's 15 operational nuclear reactors. It also reprocesses spent fuel from nuclear power plants overseas, mainly in Europe and Japan - 50,000 tons of fuel has been reprocessed on the site to date. It is where, in the early 1950s, the Windscale facility produced the Pu-239 that would be used in the UK's first nuclear bomb and also features Calder Hall, which in 1956 became the world's first commercial nuclear power station. Both buildings, for the most part, remain standing to this day. Sellafield is the largest nuclear site in Europe and the most complicated nuclear site in the world. [3] Fig. 1 shows the sheer scale of the site.
Sellafield, run by the Nuclear Decommissioning Authority, could remain one of Europe's most toxic sites for millennia. There's currently enough high and intermediate level radioactive waste to fill 27 Olympic-sized swimming pools and more waste continues to pile up. [3] Hence it only serves as a temporary waste disposal solution.
Geological disposal involves isolating radioactive waste deep inside a suitable rock volume to ensure that no harmful quantities of radioactivity ever reach the surface environment. This is achieved through the use of multiple barriers that work together to provide protection over hundreds of thousands of years. Unlike some other hazards, radioactivity will decay naturally and becomes less hazardous over time. By constructing the disposal facility deep within a geological setting whose evolution over millions of years is well understood - instead of on or near the surface - the geological formations around the engineered facility will isolate and contain the radioactivity for a very long period, thus preventing any harmful amounts of radioactivity being released into the environment in the future. Once a GDF is eventually closed, it will no longer require any human intervention (although the surrounding environment could still be monitored for as long as society wished to do so). This avoids placing the burden of dealing with these wastes on future generations. [1]
Constructing the GDF is set to be one of the most challenging engineering projects ever undertaken in the UK. The facility will be vast: surface buildings are expected to cover 1km sq and underground tunnels will stretch for up to 20 km2. [3]
The UK Government favors a consent based approach for selecting a GDF site that is based on working in partnership with willing communities. Formal engagement with potential host communities is expected to begin in early 2018 - with a total cost of the project estimated to be over 12 billion pounds and the potential to create hundreds of jobs in the community. [4] However, many communities are against having radioactive waste stored in their vicinity, and in January 2012 Cumbria County Council rejected an application to carry out detailed geological surveys in boroughs near Sellafield - the most convenient location, given its proximity. The UK government's dilemma of finding an agreeable location is by no means unique. Nuclear power stations have been built in 31 countries, but only six have either started building or completed construction of geological disposal facilities. [3] All the while, waste continues to pile up at the ageing Sellafield plant.
© Aarush Selvan. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] "Implementing Geological Disposal," UK Department of Energy and Climate Change, July 2014.
[2] "Radioactive Wastes in the UK: A Summary of the 2016 Inventory", UK Department for Business Energy and Industrial Strategy, March 2016.
[3] J. Temperton, "Inside Sellafield: How the UK's Most Dangerous Nuclear Site Is Cleaning Up Its Act", Wired Magazine, 17 Sep 16.
[4] A. Vaughan, "Search Restarts For Area Willing to Host Highly Radioactive UK Waste," The Guardian, 21 Jan 18.
