Nuclear reactor fuel element

摘要

Each rod in the element consists of a column of cylindrical fuel pellets, with concave ends in a sheath which also includes a collection chamber for fission gases. To compensate for differential coeffs. of expansion, the pellets are subdivided into sections by spring washers of low neutron capture material e.g. Zr alloy. Furthermore, internal reinforcing tubes are fitted to at least one end of the sheath to increase pressure resistance.