Many research reactors around the world use MTR type fuel elements, which are formed by assembling a number of fuel plates. Initially, the core of a fuel plate was a uranium-aluminum alloy (U-Al) containing 18 wt% of highly enriched uranium (HEU) (>90 wt% 235U) in Al. In the 1970’s, with the concern about nuclear weapons non-proliferation, the research reactors began to use fuels containing low-enriched uranium (LEU) (<20 wt% 235U). However, in order to maintain the reactivity and lifetime of the converted reactor cores, it was necessary to increase the amount of uranium in each fuel plate. This meant that for the U-Al alloy, the uranium concentration had to be increased to 45 wt% to compensate the decrease in enrichment. However difficulties arose in the fabrication of these fuel plates but this problem was overcome by the use of dispersion fuels. In that case the core of the fuel plate is a dispersion of uranium compounds in aluminum and as such could incorporate larger quantities of LEU. In this chapter, the different aspects of the research reactor fuel cycle for the UAlx-Al based dispersion fuel systems are introduced. From the basic properties of the material through the manufacturing process, proceeding to the in-pile fuel behavior and eventually the processing of the spent fuel.
|Title of host publication||Comprehensive Nuclear Materials|
|Place of Publication||Oxford|
|Number of pages||21|
|State||Published - 3 Aug 2020|
|Name||Comprehensive Nuclear Materials|