Media Contact: Ron Walli (email@example.com)|
Communications and External Relations
ORNL, Japanese reaching for stars with research effort
OAK RIDGE, Tenn.,
March 26, 1997
Before there can be fusion power plants, there have to be materials that can survive the extreme conditions within such a plant, and that's one of the focuses of research at Oak Ridge National Laboratory (ORNL).
Scientists at the Department of Energy's (DOE) ORNL and two Japanese research institutions - the Japan Atomic Energy Research Institute (JAERI) and Monbusho - are studying vanadium alloys, silicon carbide composites and steel alloys as possible materials to use in portions of a fusion plant. To discover whether these materials would be suitable, however, researchers have to improvise using a fission reactor. ORNL's High Flux Isotope Reactor (HFIR) is ideal because it produces an extremely high number of neutrons per square centimeter.
"Since we don't have a fusion reactor, we have to use HFIR to simulate the effects of radiation on a variety of materials," said Ken Thoms of the Engineering Technology Division. "To do that, though, we had to overcome several engineering obstacles."
One of those obstacles was devising a shield that stops nearly all of the slower neutrons, which cause vanadium to turn to chromium through a process called transmutation. The ORNL/Japanese team developed a shield about two inches in diameter, 30 inches long and made of cold-pressed and sintered europium oxide rings coated with ion beam-sputtered aluminum. Its properties enable it to absorb 99 percent of the slow neutrons, so it significantly reduces the transmutation of vanadium, located inside the shield.
By late next spring, after 10 irradiation cycles in HFIR, researchers will test the materials to determine the effect of irradiation on important properties.
JAERI and Monbusho, which is an umbrella organization for Japanese universities, have been working with ORNL and other universities and national laboratories for more than 15 years. For this project, JAERI and Monbusho are providing some of the materials and expertise and are contributing about $2 million per year, which is being matched by DOE's Office of Fusion Energy Science.
"The Japanese are making significant contributions toward our goal of developing the science and technology needed to develop fusion," said Everett Bloom, program manager and a member of ORNL's Metals and Ceramics Division.
Development of fusion energy, an international effort, is a long-range element of the nation's energy strategy because of its many potential advantages as an energy resource. The practical application of fusion energy, evident in the sun and stars, could help to enhance the nation's energy security, provide an environmentally acceptable alternative to fossil fuel combustion and help ensure continued economic growth.
"Fusion is still far off, but we must push on if we are ever to reach our goal," Bloom said. "Achieving our goal is critically dependent on the understanding and development of new materials."
While fusion remains a long-range goal, fusion research continues to produce advanced materials, some of which can improve fossil fuel plants. The research also has led to silicon carbide composites and other materials for use in aerospace and advanced energy technologies.
ORNL, a multiprogram research facility, is managed by Lockheed Martin Energy Research Corporation.