Reactor fuel element with internal graphite support - for enhanced thermal and structural integrity and gaseous fission product containment

Reactor fuel element of zirconium clad column stacked VO2 tablets with a bottom support of graphite of compressive strength 113.76.102 N/cm2 and tensile strength 60.95.102N/cm2 and porosity 23%. The hollow cylindrical support is machined to ensure close contact with the cladding and fuel element welded end cap to maximise heat transfer and enhance structural integrity. Gaseous fission products released during reactor operation by the fissile tablets are contained within the hollow interspace of the graphite support which also absorbs thermal expansion effects. In an alternative construction for high temperature application the interspace is insulated with Zr or AlO2 and a small inlet hole provided to compensate for loss of porosity.