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The sun as a role model: nuclear fusion – the energy of the future?

The ITER nuclear reactor is currently being built as part of an international research project. Will the energy of the future be generated through nuclear fusion?

Our sun is full of energy. Every second, it converts 600 million tonnes of hydrogen into helium and energy. This process is called nuclear fusion, during which two atomic nuclei join together, releasing a new atomic nucleus and huge amounts of energy.

Controlling nuclear fusion

Scientists have long dreamt of harnessing nuclear fusion as a source of energy.
In 1951, a team in Los Alamos in the United States managed to ignite a destructive bomb using the energy created by the fusion of deuterium and tritium. However, the nuclear fusion in the hydrogen bomb was uncontrolled. Forty years later, scientists managed, for the first time, to conduct a controlled fusion in a reactor.

In the European research reactor Joint European Torus (JET), energy-transferring plasma was ignited for roughly two seconds with an output of 1.8 megawatts. Admittedly, this required more energy than it generated. In Cadarache, France, the nuclear reactor ITER (International Thermonuclear Experimental Reactor) is currently being built, and it is hoped that it will be the world’s first reactor with a positive energy balance. The international research project was established in October 2007 by the European Atomic Energy Community (EURATOM), Japan, Russia, the People’s Republic of China, South Korea, India and the United States. They will jointly develop, build and subsequently operate ITER.

Nuclear fusion has high requirements

The technical challenges of controlled nuclear fusion are huge. A temperature of up to 150 million degrees Celsius is required to start off the fusion. That is around ten times hotter than the inside of the sun. The costs are also correspondingly high. As of 2010, the construction costs had increased from five to around 16 billion euros. If no more delays occur, the scientists will begin the first trials in 2020. A positive energy balance is to be achieved through nuclear fusion seven years later.

ITER will not produce electricity. This is to be done by the next nuclear reactor Demonstration Power Plant (DEMO). DEMO is still at the planning stage and is scheduled to be completed in 2030. Optimistic estimates suggest that commercial nuclear reactors willl produce electricity for the first time from 2050.

Fusion in the sun as an alternative

Not everyone is convinced. Critics recall that back in the 1970s the rapid establishment of commercial fusion reactors was promised. They say that nuclear fusion will not offer a global solution to the energy problem anyway, because of the high degree of complexity and high costs involved, adding that governments with limited technical and financial resources would merely be caught in a new state of dependency.

In addition, critics admonish that the use of radioactive tritium in the fusion process will produce additional radioactive waste, pointing to the advantages of producing energy through regenerative sources that have already been incorporated into Germany’s National Renewable Energy Action Plan. The use of solar energy, based as it is on the nuclear fusion inside the sun, offers a simple, safe and inexpensive alternative.

March 2013

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