Fuse applied to designing a scram device for nuclear reactor

This invention concerns a fuse and its application to the building of an emergency shutdown system for liquid sodium cooled fast reactors. The object of this system is to shut down the reactor automatically without manual intervention when an operating anomaly might cause the core fuel elements to melt. There are already aluminium fuses making up a charge in an absorbant substance forming one piece with a fixed part of the reactor and suspended above the free channel of the reactor core. In normal operation, the aluminium fuse melts at 8000C. At normal reactor operating temperature (around 5600) it is found that the fuse creeps and this could prematurely trigger off the emergency shutdown system. The object of this addendum is to improve the fuses described in the main patent specification, making it possible to achieve the cooling of the emergency shutdown system and therefore of the fuse by the sodium coolant of the reactor, whilst retaining the essential characteristics of the fuse. This fuse is not affected by any creep that might occur and this prevents an undesirable triggering off of the emergency shutdown system