Fusion Power on Line?
Fusion power is the power generated by nuclear fusion processes. In fusion reactions two light atomic nuclei fuse together to form a heavier nucleus (in contrast with fission power which breaks these bonds). To date there are no commercial fusion plants. These are expected to be less impactful than a fission plant because of less radioactive waste that can be created. The U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) has joined forces with researchers in South Korea to develop a conceptual design for a pioneering fusion facility in that Asian nation. The proposed device, called K-DEMO, could be completed in the 2030s as the final step before construction of a commercial fusion power plant that would produce clean and abundant energy for generating electricity.
Large-scale reactors using neutronic fuels (e.g. ITER) and thermal power production (turbine based) are most comparable to fission power from an engineering and economics viewpoint. Both fission and fusion power plants involve a relatively compact heat source powering a conventional steam turbine-based power plant, while producing enough neutron radiation to make activation of the plant materials problematic. The main distinction is that fusion power produces no high-level radioactive waste (though activated plant materials still need to be disposed of). There are some power plant ideas which may significantly lower the cost or size of such plants; however, research in these areas is nowhere near as advanced as in tokamaks.
Fusion power has many of the benefits of renewable energy sources (such as being a long-term energy supply and emitting no greenhouse gases) as well as some of the benefits of the resource-limited energy sources as hydrocarbons and nuclear fission (without reprocessing). Like these currently dominant energy sources, fusion could provide very high power-generation density and uninterrupted power delivery (due to the fact that it is not dependent on the weather, unlike wind and solar power).
The full K-DEMO project requires approval by the South Korean government. South Korea's National Fusion Research Institute (NFRI) will fund PPPL's initial collaboration, which will run for six months, beginning in January, and could be extended.
The cooperative agreement stands to enhance the development of fusion energy in the United States and South Korea. PPPL will explore cutting-edge designs and technologies that could benefit the U.S. fusion program. These include the National Spherical Torus Experiment (NSTX), PPPL's leading fusion experiment, which is undergoing a major upgrade.
The new collaborative agreement caps some six months of planning that included a pair of visits to PPPL by leaders of the South Korean fusion program. Plans call for the laboratory to provide engineering analysis of K-DEMO design concepts, including the size and shape of the K-DEMO tokamak and the strength of the magnetic fields that will create and control the plasma.
"We all share the same vision to deliver a possible DEMO design," said Gyung-Su Lee, a research fellow at NFRI. "We will share our expertise so that the outcome will benefit not just K-DEMO, but a next-step U.S. fusion facility as well."
K-DEMO will be comparable in size to ITER, a seven-story tokamak that the European Union, the United States, South Korea and four other nations are building in Cadarache, France. ITER is to produce 500 million watts of fusion power for 500 seconds by the late 2020s to showcase the feasibility of fusion energy. K-DEMO, by contrast, is to produce some 1 billion watts of power for several weeks on end. "K-DEMO should be just a small step away from a commercial plant in technology and performance," said Neilson.
K-DEMO will be a two-stage project. The first stage, called K-DEMO 1, will develop components for the second stage, K-DEMO 2, to produce fusion energy and generate electricity. Construction of a commercial fusion generating station would follow completion of the overall K-DEMO project.
For further information see Demo Plant.
Reactor image via South Korea's National Fusion Research Institute).