Rapid detection of fissures in nuclear fuel rod sleeves - where rod assembly is lifted from reactor core into inspection hood through which gas flows to collect any radioactive leakage due to fissure

摘要

Nuclear reactor, esp. of the light water type, contains fuel rod assemblies in its core. A travelling overhead crane is used to lift each assembly so the latter enters a hood. The upward travel of the assembly by several metres reduces the water pressure on the outside of the rods, so radioactive substances in the rods can escape into the hood if the rod sleeves contain fissures. A gas is injected into the base of the hood, so any radioactive leakage is collected and transported to an analysis appts. or counter for qualitative and quantitative analysis of the radioactive prods. present if fissures exist in the rod sleeves. Equipment used for removing fuel rod assemblies from a reactor can also be used to inspect the rods for fissures.