The search for more efficient nuclear reactor fuels has been propelled by a $1.2 million grant issued by the Department of Energy to UC Davis researcher Sergey Sarasov.
Sarasov is a professor in the physics department at UC Davis and has been working alongside researchers Kristian Haule and Gabriel Kotliar from Rutgers University in New Jersey for 10 years. The purpose of their research is mainly to address the shortcomings of uranium dioxide and in turn find more efficient sources of fuel.
“Being an insulator, [uranium] is a very bad thermal conductor because electrons do not participate in the process of heat transport,” Sarasov said in an e-mail interview. “That means when pellets get heated, the heat is transported to the outer side of the pellet inefficiently and as a result there is a huge temperature gradient from the center of the pellet to its outer area making the fuel crack and not completely burn during the nuclear cycle.”
This problem produces a lucid discrepancy in providing for more effective nuclear fuels.
“Nuclear fuels are the pellets that heat up due to nuclear reaction and the heat is transformed to electrical energy,” Sarasov said. “Therefore the fundamental problem is to make this process as efficient as possible meaning that the entire pellet has to be efficiently burned out during the nuclear cycle.“
The research is now aimed at actinides, which comprise the bottom row of the periodic table.
Kotliar, a professor in the Department of Physics and Astronomy at Rutgers University, pointed out that this part of the research is the hardest to produce material design for.
“Being able to design material on the computer will accelerate the process of discovery of materials with desirable properties,” he said.
“[The money provided by the grant] will allow us to hire post doctoral scholars to develop the necessary codes to investigate the materials,” Kotliar said.
Sarasov added that the funding would support safety measures in handling the materials of such an experiment.
“The money invested into the development of theoretical and computational tools that would allow us to avoid experiments with nuclear materials which, in general, require complicated installations and set-ups and very special handling due to their toxicity and radioactivity and as a result is extremely expensive,” he said.
The potential benefits of the knowledge gained from this research involve gaining information to allow for computations.
“Computations of thermal conductivity will be important to guide the search for new materials, alloys and compounds with lower thermal resistances and higher melting temperatures,” Sarasov said. “[This will] have a significant impact on advanced nuclear energy systems of the future.“
SADAF MOGHIMI can be reached at email@example.com.