High temperature gas cooled reactor fuel elements

The fuel element described comprises a tubular member composed of a number of fuel-containing annular disks superimposed one on the other, with provision for coolant flow between at least some of the adjacent disks. The disks comprise one or more layers of fission product retaining fuel particles embedded in graphite or other matrix material shaped to allow coolant to sweep between the faces of adjacent disks. It is preferred that the disks contain two layers of coated fuel particles fixed in matrix material. (UK)