Fusion energy could be the future

durham university31 August 2015

Illustration of tokamak with plasma © ITER Organization

Fusion energy offers the tantalising possibility of clean, sustainable and almost limitless energy. But can it be an economically viable option?

Research led by Durham University, in collaboration with the Culham Centre for Fusion Energy, has looked in-depth at the economics of fusion energy.

The team calculated the cost of building, running and decommissioning a fusion power station and how this compares to current fission nuclear power plants.

They concluded that a fusion power plant could generate electricity at a similar price to a fission plant.

Professor Damian Hampshire, of the Centre for Materials Physics at Durham University, who led the study, explains: “Obviously we have had to make assumptions, but what we can say is that our predictions suggest that fusion won’t be vastly more expensive than fission.”

Such findings support the possibility that, within a generation or two, fusion-generated energy could become a reality.

Professor Hampshire hopes that the study will help persuade policy-makers and the private sector to invest more heavily in fusion energy.

“While there are still some technological challenges to overcome, we have produced a strong argument, supported by the best available data, that fusion power stations could soon be economically viable.

We hope that this kick-starts investment to overcome the remaining technological challenges and speeds up the planning process for the possibility of a fusion-powered world.” he said.

The study considers recent advances in high temperature superconductors, which could be used to build the powerful magnets that keep the hot plasma in position inside the containing vessel, called a tokamak, at the heart of a fusion reactor.

These developments mean that superconducting magnets could be built in sections, rather than in one piece. This would help to reduce the costs of maintenance by allowing individual sections of the magnet to be repaired or replaced, rather than the whole device.

Fusion reactors create energy in a similar way to the sun, heating plasma to around 100 million degrees centigrade. At this temperature, hydrogen atoms fuse together and release energy.

This differs from more traditional fission nuclear reactors that create energy by splitting atoms at lower temperatures.

So what advantage does fusion energy offer over fission? Fusion reactors are safer. They produce no radioactive waste and there is no high level radioactive material to potentially leak, meaning that disasters such as Chernobyl and Fukushima are impossible.

Fusion energy is also politically favourable. It does not produce any weapons-grade products that could proliferate nuclear arms. Security of supply is not a concern either as the fuels for the reactors, deuterium, or ‘heavy water’ which is extracted from sea water, and tritium, which is created within the reactor, are readily available.

The study, which was commissioned by Research Council UK’s Energy Programme, does not include the costs of disposing of radioactive waste as, unlike a fission plant, no radioactive waste is created. The only radioactive material would be the tokamak, which would become mildly radioactive during its lifetime.

A test fusion reactor, the International Thermonuclear Experimental Reactor, is about 10 years away from operation in the South of France. Its aim is to prove the scientific and technological feasibility of fusion energy.

The research paper is published in Fusion Engineering and Design journal and can be accessed via Durham Research Online.