Nickel alloys for structural elements - resistant to swelling during fast neutron irradiation e.g. in a sodium cooled reactor

摘要

Structural elements for a fast neutron nuclear reactor, are fabricated from an alloy of Ni and at least a body (M) selected from Fe and Si in weight proportion such that on irradiation by fast neutrons the compounds Ni3M is formed without appreciable swelling of the element concerned. Pref. the alloy may incorporate Cr and/or Mo. Esp. the alloy is of Ni/Fe and contains 20-70 wt.% Fe or of Ni/Si and contains 0.5-10 wt.% Si. Structural elements, partic. fuel rod sleeves or fuel assembly casings subject to high temp., corrosion by liquid sodium coolant, and the effects of fast-neutrons on the lattice structure of the alloy, can be produced which in contrast to the usual stainless steel or similar alloy materials are not subject to dimensional changes leading to swelling and ultimately to rupture.