Scientists from the Belgian Nuclear Research Center, along with France’s National Research Council and Atomic Energy Commission, have developed a reactor that relies on a particle accelerator to sustain fission – a technology with the potential to safely eliminate some of the longest-lived components of nuclear waste.
Last week the scientists announced successful operation of a 1-kilowatt, lead-cooled reactor that serves as a predecessor to the 57 megawatt MYRRHA (Multipurpose Hybrid Research Reactor for High-tech Applications) slated for construction in 2015. Instead of creating a critical mass of fissile material, the setup uses a subcritical fuel configuration. Through a process called spallation, a proton beam in the larger reactor will hit a heavy metal target that then throws off enough neutrons to start a chain reaction, which stops when the proton beam is turned off. The smaller reactor used recently to simulate MYRRHA operations uses deuterium ions hitting a tritium target.
Of most interest to industry is the potential to apply the technology to the management of spent nuclear fuel. An accelerator-driven system (ADS) could be configured to transmute the waste’s lower actinides into much safer materials or elements with significantly shorter half-lives.
"What is unique in this experiment is that we are reproducing exactly the characteristics of an ADS on an industrial scale," Belgian Nuclear Research Center deputy director Hamid Ait Abderrahim was quoted as saying by the Science Insider blog of the American Association for the Advancement of Science.
The ADS concept has been discussed since the 1950s and was first shown to work by researchers at Japan’s Kyoto University in 2009.