Pressure-tight capsule for introducing marking materials - for detecting leakage in fuel, fertile or absorber rods in nuclear reactor

摘要

Pressure-tight capsule for introducing gaseous marking materials comprises a sleeve which can be closed by a lid which is fixed in the capsule opening by soft solder. The capsule is pref. lined up within the fuel, fertile or absorber rod in such a way that, when the solder melts, the lid falls out of the capsule opening under the action of gravity, thus releasing the opening. An outwardly projecting capillary tube which can be closed by melting pref. extends through the lid. The capsule opens automatically in operation of the rod, releasing the mixture of inert gases which becomes dispersed over the interior of the rod.