CORVALLIS, Ore. – It’s really hot, but also energy efficient, very safe and produces no greenhouse gases. And potentially it could provide hydrogen at low cost to fuel the automobiles of the future.
Those are the driving forces behind research on a new “super hot” type of nuclear reactor that has begun at Oregon State University, with a five-year, $6 million grant from the Nuclear Regulatory Commission. The project may herald another major step forward for the nuclear power industry.
These high-temperature, gas-cooled reactors are quite different from their water-cooled counterparts that now provide a significant portion of the world’s electricity. They operate at temperatures that may exceed 2,000 degrees – about three times as hot as existing reactors – but are also about 35 to 50 percent more energy-efficient, cost less to build and create 50 percent less radioactive waste. Because fuel is dispersed, they won’t melt down.
And besides producing electricity, the high temperatures of this type of reactor could alternatively be used to directly separate water into its hydrogen and oxygen components at much less cost than traditional approaches such as electrolysis. The hydrogen, in turn, could be used in hydrogen fuel cells to power automobiles – an attractive technology since its only by-product is simple water, not toxic exhausts and greenhouse gases.
“The concept of high-temperature reactors has been known for some time,” said Brian Woods, an OSU assistant professor of nuclear engineering. “But it’s only become more practical with the material science advances of recent years, like the development of special steel alloys that will be able to resist the very high temperatures.
“We know we can build this type of reactor, but just how hot we’ll be able to operate it still remains a question to be answered,” Woods said. “Many of the questions relate not so much to the technology as to the materials, such as the fuel, reactor vessel and fuel support structures. Some material in existing reactors would literally melt at these temperatures, but new materials currently being developed should be able to take it.”
Although such extraordinary levels of heat sound somewhat ominous, reactors of this type should actually be even safer than their water-based counterparts, Woods said.
“With water you’re always concerned about a leak and loss of coolant, and those are issues our new passively-safe reactors have been designed to address,” he said. “These high-temperature gas reactors are designed to remove heat during an accident without the addition of any additional coolant. These types of accidents are exactly what we plan on examining at Oregon State in the near future.”
OSU’s role in this project is to build a one-quarter scale reactor and test designs, see what works best, simulate accidents, and provide safety data to regulatory agencies. The facility itself will cost $3.6 million and the remaining funds will be used for experiments and simulations. Texas A&M University and the University of Michigan are also partners in this project.
Two different designs for these types of reactors are already under way in at least three consortiums in Japan, China, South Africa and the United States, and license applications could be on their way to the NRC within five to seven years, Woods said, if not sooner.
Design of the facility to be based in the OSU Department of Nuclear Engineering and Radiation Health Physics is being done now, and actual construction should begin within a year, officials said. The heat in the test facility core will be simulated using electric heaters, and it will not actually use any nuclear materials.
“I’m confident that reactors of this type will play a role in our energy future,” Woods said. “They make electricity very efficiently, they should be very safe, they may provide a way to produce hydrogen at low cost, and like other nuclear reactors they produce no greenhouse emissions.”
OSU was selected for this project, Woods said, in part because of its experience in the 1990s and later when the university built and operated test facilities that led to creation of the “passively safe,” next generation nuclear reactors now being constructed around the world.
The new facility and testing programs will also provide opportunities for OSU graduate assistants and even undergraduate students to gain experience working with some of the newest nuclear power technology in the world, educators said.
Click photos to see a full-size version. Right click and save image to download.