New fuel design enables efficiency in new nuclear reactors

A new approach to nuclear fuel developed at Oak Ridge National Laboratory could enhance the performance of new light water nuclear reactors.

Light water reactors make up most of the U.S. operating nuclear reactors and generate power using uranium dioxide fuel pellets. The Uranium Dioxide Liquid Metal Suspension (ULIMES) fuel concept offers a next step for fuel innovation. Designed at ORNL to cool the reactor more efficiently and extract even more energy from uranium fuel, ULIMES aims to improve overall reactor performance.

The ULIMES design uses uranium dioxide fuel particles suspended in liquid metal to form a flowing fuel system that circulates fuel through a reactor core. This design improves a reactor's ability to cool itself, offering a major gain in efficiency, in addition to driving significant safety gains and lowered maintenance costs. The concept is also compatible with materials already used to construct light water reactors.

"ULIMES bridges today's reactors with tomorrow's technologies, using proven materials to provide next-generation performance without next-generation construction costs," said ORNL's Ian Greenquist.

ORNL has signed a research license agreement with Australian investment firm Out The Back ventures to fund additional ULIMES research.