The research to improve the performance of coated-particle nuclear fuel met an important milestone by reaching a burnup of 9 percent without any fuel failure. Raising the burnup level of fuel in a nuclear reactor reduces the amount of fuel required to produce a given amount of energy while reducing the volume of the used fuel generated, and improves the overall economics of the reactor system.Pretty exciting stuff.
The [Idaho National Lab] team studied the very successful technology developed by the Germans for this fuel in the 1980s and decided to make the carbon and silicon carbide layers of the U.S. particle coatings more closely resemble the German model. The changes resulted in success that has matched the historical German level.
INL's Advanced Test Reactor was a key enabler of the successful research. The ATR was used to provide the heating of the fuel to watch the fuel's response. The fuel kernel is coated with layers of carbon and silicon compounds. These microspheres are then placed in compacts one-half-inch wide by two inches long and then placed in graphite inside the reactor for testing. The fuel element is closely monitored while inside the test reactor to track its behavior.
The team has now set its sights on reaching its next major milestone -- achievement of a 12-14 percent burnup* expected later this calendar year.
*A burnup is a measure of the neutron irradiation of the fuel. Higher burnup allows more of the fissile 235U and of the plutonium bred from the 238U to be utilised, reducing the uranium requirements of the fuel cycle.