New reactor shutdown mechanism

Purpose: To conduct reactor shutdown by using a fuse and make a direct response to the power increase, i.e., increase in the neutron fluxes. Constitution: A fuse prepared with metal uranium is disposed at the midway of a cable for supplying control rod maintaining power source, and an electromagnet connected with the cable is disposed at the midway of a connection pipe. Upon occurrence of abnormality, if the temperature rises in response to the increase in the reactor power, the fuse is melted down to interrupt the control rod maintaining power source. Accordingly, the electromagnet loses the magnetic force to disconnect the connection pipe, by which the control rod is dropped into the reactor core to conduct reactor shutdown. (Yoshino, Y.)