Solving nuclear power’s biggest problem

As we enter a new era of nuclear power, there are renewed concerns about what to do with the waste generated by nuclear power plants. Nuclear waste is toxic and can remain radioactive for about 10,000 years, which means it must be disposed of properly to ensure the safety of people and the environment. Despite the challenges involved, several countries around the globe are pursuing new nuclear energy agendas in support of a green transition and coming up with innovative ways to dispose of radioactive waste produced in nuclear facilities.

Nuclear power generation results in the production of waste. There are three types of nuclear waste: low-, intermediate-, and high-level radioactive waste. Most of the waste produced at nuclear power plants consists of lightly contaminated items, such as tools and work clothing, with a radioactivity level of about 1 percent. High-level waste is composed of spent fuel, which represents about 3% of the total volume of waste from nuclear energy production, although it contains 95% of the radioactivity.

The nuclear industry is responsible for the safe disposal of waste by building disposal facilities. One of the positive things about nuclear energy production is that it generates very little waste compared to other energy sources. Nuclear fuel is very energy dense, meaning it takes little to generate large amounts of electricity. Therefore, it produces little waste, around 5 grams of activity waste to provide one person’s annual energy needs. A conventional 1,000 MW nuclear power plant, which can supply electricity to over a million people, produces around three cubic meters of vitrified mining waste per year, which is much less than that produced in coal-fired power plants.

Nuclear power companies must store spent fuel in wet or dry facilities to be either recycled or disposed of. The spent fuel coming out of the reactor is hot and radioactive, and storing it in water allows it to cool and the radioactivity levels to drop. Several countries, including the US, treat this spent fuel as waste. However, many countries recycle their spent fuel, including France, Japan, Germany, Belgium and Russia. About 97% of spent fuel can be reused in certain types of nuclear reactors.

High-level nuclear waste can be used in fast neutron reactors that operate in a closed fuel cycle. These reactors can extract 60 to 70 times more energy from natural uranium than thermal reactors, which helps increase efficiency and reduce radioactive waste. Mikhail Chudakov, Deputy Director General and Head of the Department of Nuclear Energy at the International Atomic Energy Agency (IAEA) explains: “When fast reactors are used in a closed fuel cycle, one kilogram of nuclear waste can be recycled several times until Uranium is used, and the actinides – which remain radioactive for thousands of years – are burned. What is then left is about 30 grams of waste that will be radioactive for 200 to 300 years.”

While some countries are recycling their nuclear waste, using special reactors, others are looking for safe ways to dispose of it. Finland plans to bury its spent nuclear fuel in the world’s first geological grave, where it can be stored for 100,000 years. The project is considered revolutionary for the nuclear power industry, which has long sought a safe method of long-term waste disposal. If successful, it could be replicated in many areas of the world. In 2025 or 2026, finishing company Posiva hopes to begin packing spent nuclear waste into sealed copper containers to store in bedrock 400 meters below the forests of southwestern Finland. The long-term disposal facility, known as Onkalo, is located next to three nuclear reactors on the island of Olkiluoto.

Pasi Tuohimaa, head of communications at Posiva, said several nuclear power companies have contacted Posiva to learn more about the project. Tuohimaa said: “Having a solution for the final disposal of spent fuel was like the missing part of the sustainable life cycle of nuclear power.”

Gareth Law, professor of radiochemistry at the University of Helsinki, explained: “There are many countries in the world that are still in the planning phase and are actually trying to find a place to dump the waste. So the fact that Finland (has) built a repository now and in the next year or two we’re going to operate it and start the disposal process… I don’t want to call it a miracle, but that wouldn’t be a bad way to frame it in a global context.”

Several countries around the globe, including the UK and the US, have long sought options for the safe and long-term disposal of nuclear waste, with limited success. The Onkalo project offers hope to the industry, with other countries expected to develop similar disposal methods in the future. Furthermore, in support of a global green transition, it is likely that more countries will invest in recycling schemes to reuse and reduce nuclear waste before looking for ways to dispose of the remaining waste.

By Felicity Bradstock for Oilprice.com

More top reads from Oilprice.com