The fuel pellets contain a kernel of enriched uranium surrounded by carbon and carbide layers that act as a containment boundry for the radioactive material.
Idaho National Laboratory (INL) scientists have set a new world record of 19% burn with next-generation particle fuel for use in high temperature gas reactors (HTGRs).
INL researchers say the fuel experiment set the record for particle fuel by consuming approximately 19 percent of its low-enriched uranium — more than double the previous record set by similar experiments run by German scientists in the 1980s and more than three times that achieved by current light water reactor (LWR) fuel. Additionally, none of the fuel particles experienced failure since entering the extreme neutron irradiation test environment of the ATR in December 2006.
INL has been working with Babcock and Wilcox Inc., General Atomics, and Oak Ridge National Laboratory (ORNL) to establish standards and procedures for the manufacture of commercial-scale HTGR fuel. The overarching goal of the AGR Fuel Program is to qualify coated nuclear fuel particles for use in HTGRs such as the Next Generation Nuclear Plant (NGNP). Developing particle fuel capable of achieving very high burnup levels will also reduce the amount of used fuel that is generated by HTGRs.
The Next Generation Nuclear Plant Program aims to use a high-temperature gas reactor to produce high-temperature process heat and hydrogen used by many industrial facilities in daily operations and to support the broader goal of developing the next generation of nuclear power systems that provide abundant carbon-free electricity on a 24/7 basis. Excellent fuel irradiation performance must be demonstrated before high-temperature gas reactors can be licensed and co-located with these complementary industrial facilities. Reaching this world record peak burnup of 19 percent without any particle failure demonstrates the robustness of this particle fuel design.
China has begun building a 200 MWe High Temperature Pebble bed reactor that they expect to complete in 2013 and then factory mass produce by the dozen. Future versions of the Chinese pebble reactor could shift to the more advanced INL type pebbles. China would license INL technology or develop comparable technology on their own.
There has been advanced theoretical designs which indicate that future advanced pebbles could achieve 65% burn.
The New York Times has coverage of the INL work to develop advanced pebble reactors