fusion reactor feasibility. The first third of the twenty-first century may then see a prototype fusion power plant in operation, depending on the energy cost and environmental situation at that time. The cost of nuclear fusion is expected to be very high in comparison with alternative nuclear reactor designs. On the other hand, nuclear fusion offers additional environmental protection compared to nuclear fission. By midcentury, some fraction of energy to the national electrical grids might possibly come from fusion reactors.
The advantages of fusion power with respect to safety and the environment follow:
• No danger from nuclear reactor runaway. The amount of nuclear fuel in the reaction chamber at any given time is minuscule, and a system failure of any sort can lead only to a cooling down of the reacting plasma.
• Enormously reduced amounts of nuclear waste. The nuclear ash from fusion is helium, a stable and totally benign gas. Almost all of the neutrons coming out of the reacting gas will be absorbed in a lithium 6 blanket, generating fresh tritium to replace that used up in the deuterium tritium reactions. Also, although the vacuum-chamber wall is expected to become radioactive due to bombardment by these transiting neutrons, the material of the vacuum chamber can be chosen to reduce the radioactivity level and character of this radioactivity and problems associated with storage or disposal. Further research is needed in this area.
• No production of gases deleterious to the environment such as oxides of carbon and nitrogen; however, there is some concern on the potential leakage of tritium into the water supply.
• No inherent production of fissile materials.
The acid test of fusion power feasibilityachieving nuclear ignition in a confined plasmais anticipated no earlier than the end of this decade, and a prototype fusion power plant should not be expected before the year 2020. Further progress is clearly needed in the science, technological development, and economics of nuclear fusion before it can actually be implemented. Nevertheless, in view of its minimal impact on atmospheric pollution and greenhouse warming, and the very much reduced level of nuclear hazard, controlled fusion still merits its reputation as a major option for the future generation of electric power.
Golay, M. W. 1990. Testimony before the U.S. House Committee on Interior and Insular Affairs. Washington, D.C., March 10, 1990.