Fusion - Is it just a Dream?
Interview with IAEA Fusion Physicist Ralf Kaiser

Date Published: 12 October 2012

Ralf Kaiser, IAEA Fusion Physicist, explains why he believes fusion will someday deliver a nearly limitless supply of non-polluting, carbon-neutral energy. <br /><br /> © IAEA Ralf Kaiser is a physicist who dedicates much of his time to fusion research at the IAEA. We met him to learn more about it. "We need to be prepared for the day when oil and gas supplies are depleted", Kaiser says. For Kaiser fusion is also an essential option because, "We may have to abruptly cease burning fossil fuels to avoid tipping planetary systems into catastrophic climate change." Scientists are working on a project that could produce a nearly limitless supply of non-polluting, carbon-neutral energy. And its fuel can be found in water. It is called fusion. Fusion is the energy source powering the sun and the stars. Fusion is fuelled by two isotopes of hydrogen: deuterium, a harmless isotope of hydrogen found in seawater, and tritium, a rare, short-lived, radioisotope. Just 250 kilogrammes of a deuterium/tritium mix would be sufficient to fuel a 1,000 megawatt fusion power plant for a year. Someday the heat generated by a fusion reactor will drive turbines to generate electricity. Fusion research has been a focus of the IAEA's programme since the Agency's establishment over 55 years ago. In this photo, scientists from 28 nations, attending an IAEA conference in Salzburg, Austria, in September 1961, discuss plasma physics and controlled nuclear fusion research. The ITER project has grown out of the IAEA's long-term commitment to fusion research. ITER is an experimental reactor project designed to produce 10 times as much energy as is needed to trigger fusion. It will pave the way for the design and operation of the first electricity-producing fusion power plant. Fusion physicist Ralf Kaiser is convinced that "we need to pursue fusion, because we need zero carbon energy to survive in the coming centuries. Fusion will be a crucial part of the solution to this problem." "Sustaining a fusion reaction is an enormous engineering challenge. You need electro-magnets that are 100,000 times stronger than the Earth's magnetic field to trap the plasma, keep it spinning around in the confinement vessel and make sure that the nuclei collide as often as possible with one another." "Then you need to heat the plasma to a temperature ten times hotter than the Sun's 150 million °C." "The spinning, super-hot plasma is confined in a vessel shaped like a hollow "doughnut", and known as a toroidal fusion reactor." "Hydrogen fuel is injected into the spinning plasma, where hydrogen nuclei fuse, producing helium nuclei. When the nuclei fuse, they release energy. Scientists want to create an "ignition" or a "burning plasma" reaction process that produces enough heat and helium nuclei to maintain the plasma's temperature without external power." "A "meltdown" is not possible in a fusion reactor. If anything goes wrong, the plasma cools and the reaction stops." "Fusion research, carried out by scientists from all over the world, has made tremendous progress in recent decades." "Fusion is no longer just a dream," Kaiser says. "I expect ITER to produce net energy from fusion before I retire. And I believe that for the generation of my grandchildren fusion power will be an every day reality." © IAEA