The challenge to keep nuclear fusion alive as a future energy source

摘要

Few people are preoccupied with the energy issue. Indeed, inflation-corrected energy prices (in euros) are currently lower than before the first oil crisis of 1973; the annual growth rate of primary-energy use in the industrialized world has diminished considerably compared to before 1970, and oil and gas production is characterized by increased exploration activity and a wider geographical spread. Nevertheless, there is areal energy issue. If the greenhouse effect turns out to be real, then mankind should at least slow down the consumption of fossil fuels. Given the fact that world energy consumption (especially by the developing countries) will rise in the future, and that nuclear fission power has become unpopular in the western world, the idea reigning in some circles to cope with this situation by total reliance on energy savings and renewable energy sources comes close to wishful thinking. A realistic analysis makes it clear that there will be a need for large workhorses for electricity generation to keep the overall electricity grid sufficiently robust. From a global and long-term perspective, the logical conclusion is the following: because mankind cannot count on the continued use of fossil fuels (due to the finiteness of the resources combined with the possible climate change effects), our generation has the responsibility to develop alternative energy sources for the distant future. Many parallel lines of research and development therefore need be pursued; because of the uncertainties with other alternative sources, it would be irresponsible to kill some of these development lines. This holds for renewable sources, the nuclear fission breeder, and for nuclear fusion. A major hurdle for the survival of long term energy research and development is the liberalization of the electricity market. Because of the revolutionary changes taking place, utilities concentrate on cost cutting and short-term survival. In addition, they are no longer supposed to take responsibility for the future strategic electric energy provision. Although they may be sympathetic to the further development of nuclear fusion research, they do not have any interest in financial support. According to utilities operating in a liberalized market, the research and development for energy technologies must be performed by the manufacturers;if these develop an interesting product, then utilities may buy it. Manufacturers in turn consider the payback time of fusion research and development investments too large to put much money into it. Public funding therefore remains the only option for the next few decades. But strangely enough, regardless of the requirements for a long-term energy policy, policy makers also concentrate on short-term returns. Everybody is blinded by the current cheapness of energy. Utilities will only buy fusion plants if they are competitive. The initial investment cost should therefore be reasonable, the construction time limited, and the availability for operation sufficiently high. Present-day cost estimates for fusion power plants carry little weight; they merely serve to indicate the weak spots in present-day designs. However, there is no doubt that the future fusion reactor must become much simpler and more robust than present-day experiments. Future competitiveness of fusion plants will largely depend on the price of other energy sources. Time works in the right direction for fusion the other sources will become more expensive, and present-day sophisticated technologies characteristic for fusion (superconductivity, remote handling, etc) will by that time have become daily technologies at a reasonable cost: Fusion may succeed in developing a good electricity generating product for the second half of the 21st century. The major challenge consists of finding sufficient financial funding for the continued development of fusion research. [References: 14]