Tubular sheath for nuclear fuel rod - with wall thickness varying in accordance with neutron flux density at different positions along sheath wall

摘要

Nuclear reactor fuel rod with the smallest possible proportion of tubular sheath material, partic. for nuclear reactors of high conversion or breeding rates, in which the pressure strength of the tubular sheath is varied by variation of the wall thickness or other constructional reinforcing precautions in local correspondence with the varying inner loading due to swelling of the nuclear fuel. In particular, the pressure strength is increased in zones of greatest neutron flux density. Savings in the sheath construction materials e.g. stainless steel or Zr alloy are considerable.