Global dilemma of nuclear waste management 04 Jun 2020

The world has been living with a nuclear environment for more than 75 years, for defence, for power generation and in the fields of science, research and medicine. As the amount of nuclear material and the waste it generates has grown exponentially, the long-term management of the spent and decommissioned nuclear fuel and contaminated materials remains an issue that lies embarrassingly and interminably stalled in many nuclear countries, which are almost every country of the world, perhaps not as part of nuclear defence strategies or nuclear power policy, but certainly for research and medicine.

Generation of nuclear power worldwide in 2017Credit: WNA

Ironically, some countries, notably Australia, are non-nuclear defence and non-nuclear power countries, but have large deposits of uranium, the base element of nuclear fission. A further irony for Australia, is that its arid, barren, inhospitable red centre represents, debatably, the most suitable location for the long-term disposal of nuclear waste.

The root causes of much of the inertia in advancing long term management of high level radioactive waste is based on the classification of the waste and the politics of waste management strategies.

It is difficult to investigate the scale of use, waste generation and management in the nuclear defence industries, which the consensus for all around the world assumes, despite international limitation agreements, is still significant. The same data for peacetime industries can be researched and reported with the assistance of international associations including the IAEA, International Atomic Energy Association of the United Nations and the World Nuclear Agency (WNA). The WNA, an agency headquartered in the UK and with a membership of international companies and organisations, promotes a wider understanding of nuclear energy by producing authoritative information, developing common industry positions, sharing best practices, and contributing to the energy debate.

For the management of civil and military use waste there are four main categories; low level, intermediate level, high level waste and spent nuclear fuel. Examples of low level waste include radioactively contaminated clothing, cleaning mops, filters, equipment and tools and medical tubes, swabs and hypodermic syringes. Intermediate waste comprises resins, chemical sludge and metal nuclear fuel cladding, as well as contaminated materials from reactor decommissioning. High level waste is the highly radioactive materials produced as a by-product of the reactions that occur inside nuclear reactors and takes one of two forms with spent reactor fuel considered to be waste when accepted for disposal. Spent fuel can also be reprocessed, which generates its own volumes of nuclear and contaminated waste. For the purposes of storing or disposing of waste, the thermal heat generated by nuclear waste is as much of an issue as its radioactive level. Nuclear material can emit temperatures of 200-250ºC and controlling the build-up of heat in the management of waste is a significant design consideration.

First floating nuclear power reactor by Russia

In some countries, including Germany, waste, for the purposes of management and disposal, is classified as heat generating and non-heat generating with the two types being disposed of in different types of repositories.

The greatest volume of civil-use nuclear waste is generated by the nuclear power industry. According to the World Nuclear Association (WNA), there are 440 operating nuclear power reactors today in 31 countries. These operating reactors have a total installed electricity producing capacity of 2.653 trillion kWh and represent about 10.5% of the world electricity generation.

Together with the operating generators others are being planned, are in construction, or ready to come online. These include the first floating nuclear power plant, the Akademik Lomonosov in Russia. “It is one of the first of the new type of smaller reactors that will bring nuclear energy to smaller grids and for different applications,” said John Lindberg of the WNA.

Countries are also building their first nuclear power plants to add to the 31 countries with nuclear power generation. In the United Arab Emirates, the first of four reactors was loaded with fuel to begin supplying electricity later in the year; the first of two reactors in Belarus is due to start later in 2020; construction of the first of four reactors has started in Turkey and the first two reactors in Bangladesh, and with plans for the first schemes in Egypt and Uzbekistan.

“Of all the used fuel discharged from reactors, about one third has been recycled, with the remainder kept in storage pending either reprocessing or final disposal,” said Lindberg. “The reprocessing of nuclear materials is a well-established practice in France, Russia and the UK and there are innovative reactor designs being developed that can use up to 97% of the fuel, compared with about 3% in current reactors,” he added.

Scope of an underground nuclear waste repository

The consensus of opinion among scientists, engineers, users of nuclear materials and the general public, is that the safest place for the storage of nuclear waste of all levels, and if we have to have it, is underground. This creates interest for the industry and the potential for design, excavation and construction of underground waste repositories is tremendous. The storage of existing volumes of waste currently stored temporarily on the surface or awaiting final long-term storage is hard to visualise.

The UK, for example, which commissioned the world’s first fully operational nuclear power plant at Calder Hall at Windscale in England in October 1956, currently has 15 operating nuclear power reactors, and is presently building new reactor C at the Hinckley Point power station, had a radioactive waste inventory of 133,000m3 in early 2019. Underground facilities to hold existing and projected volumes of nuclear waste are labyrinths of expansive scale.

The question as to why these underground facilities for the long-term storage of nuclear waste are not in construction or already constructed is a question of politics.

Rather than the issue being a universal concern to be addressed and resolved, it is an issue for the management of each individual nation and subject to individual national political systems and public opinion. While the IAEA and the WNA coordinate expertise from across the world to inform global policymaking for the management of nuclear waste, their member nations all make their own decisions and policies.

Expanse of an excavated underground hydro scheme machine hall

In the case of the UK and other democratic government countries, the policy is that the siting of any underground nuclear waste repository has to be with the agreement of the people of the location, in other words, the hosting of an underground storage facility has to be on a voluntary basis. This is a notoriously difficult process to promote and market from a national government perspective, leading to a state of inertia. For governments and politicians, it becomes a matter of low priority since, if the waste has been managed to date without any issues, what is the urgency for an expensive dedicated underground facility for its storage. This is a collective attitude while individually, politicians know the management of the accumulating nuclear waste is a critical issue for future generations and the safe management of an environmentally dangerous material.

It is the thankfully rare occasion of accidents and disasters in the nuclear industry that concentrates political attention and moves the debate. Most recently it was the disaster of the Chernobyl power station in Ukraine, as part of the former Soviet Union in 1986, and the disaster of the Fukushima power plant after the catastrophic tsunami of March 2011 in Japan, that raised public awareness once again. In the case of the disaster in Japan it had the direct effect of leading the people and the government of Germany to reject nuclear power generation, closing eight of its 17 nuclear reactors immediately and to begin decommissioning of them all by the end of 2022.

That the industry can design, excavate and construct the underground spaces specifically for the storage of nuclear waste, there is no doubt. The references are the long road and rail tunnels excavated around the world and the impressive underground caverns excavated for the machine halls of hydropower plants and for the CERN particle physics research laboratory in Switzerland. It is often wondered why nuclear reactors are not built into underground caverns. That the underground is the best feasible location for the nuclear waste they generate is of no question and that is the scientific recommendation being pursued by all countries, no matter how frustratingly slowly.

Additional articles of the nuclear waste management focus will examine the status of underground nuclear waste management programmes in several countries with contributions from leading professionals associated with these programmes.