Sustainable nuclear energy for a new generation

May 30th, 2014 James Caron

Scientist puts forward a sustainable energy plan where nuclear fuel is created using magnetic or laser fusion. News accounts are coming in daily confirming that the reliance on fossil fuels for energy is adversely affecting the world we live in: the National Climate Assessment detailed how climate change is creating havoc with our planet today and lists the burning of fossil fuels as the predominate cause; two teams of scientists just reported the irreversible glacial collapse of an Antarctic ice sheet as a result of warming ocean temperatures; and California's record drought and heat are producing wildfires and driving up food prices. It is evident that we must invest in alternative methods of energy production as soon as possible. Nuclear energy produces carbon free energy, and is responsible for 13% of the world's electricity today, but fission-based reactors present environmental hazards and utilize less than 1% of the fuel. Nuclear fusion has held promise that the process will provide clean energy with a limitless supply of fuel. However, decades of research have not produced a viable nuclear fusion power plant. Is there another path forward? In the June issue of the Journal of Fusion Energy, Dr. Wallace Manheimer has laid out a plan that would enable Fusion Breeding as a means to meet mid-century energy needs, based on the scientific underpinnings of current fusion technology and on current nuclear infrastructure. In this approach, a Fusion Reactor is designed to not only produce electricity, but also to create nuclear fuel that can run thermal nuclear reactors. A fusion breeder is about ten times as a prolific a fuel producer as a fission breeder, i.e. a fast neutron fission reactor such as the Integral Fast Reactor. The process, called Fusion Breeding, uses the energetic fusion neutrons to create fuel as well as heat water for the production of electricity. A Deuterium-Tritium fusion reactor is surrounded by a blanket that contains Thorium-232 and other materials to slow and multiply the neutrons. The additional neutrons can be used to breed uranium-233, an especially good nuclear fuel that can be used in today's light water reactors. The waste products from the U233 reactor come in two forms; fission products like strontium 90 which have half lives of about 30 years, and actinides like plutonium which have half lives of 24,000 years. The fission products could be stored for a few hundred years until they become inert. However the actinides, which would have to be stored for hundreds of thousands of years, can serve as fuel for an Integral Fast Reactor. The fuel produced by a single Fusion Breeder could supply at least 5 thermal nuclear reactors of equal power, and a single IFR could burn the plutonium waste of about conventional 5 light water reactors. This is the basis of the mid-century energy architecture suggested in the paper. The requirements for creating a fusion breeder in regards to power multiplication, wall materials and fractional on time are considerably relaxed when compared to a pure fusion reactor. Even making the most optimistic assumptions about pure fusion, fusion breeding would be achieved decades earlier and could serve as a bridge technology of real economic value. Dr. Manheimer's plan would leverage current research facilities, such as ITER in Southern France and the National Ignition Facility at Lawrence Livermore National Laboratory, to facilitate an energy source that is sustainable, proliferation resistant, safe, and economically and environmentally sound. Dr. Manheimer, currently a consultant for Research Support Instruments in Lanham, Maryland, has gained extensive knowledge of both magnetic and laser fusion during his 44 years as a scientist for the Naval Research Laboratory. This paper represents 15 years of researching a more practical approach to fusion energy production. The paper is open access and can be read at on the Journal of Fusion Energy website. More information: Manheimer, Wallace. "Fusion Breeding for Mid-Century Sustainable Power." Journal of Fusion Energy 33, no. 3 (2014): 199-234. Provided by Research Support Instruments

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