Reactor emergency detection system

A reactor emergency detection system is disclosed in which at least one fuel element disposed within a reactor core is caused to exhibit an emergency condition prior to the other fuel elements within the core while this induced condition is sensed and detected through suitable sensing means. A non-exothermic partition is disposed within the reactor coolant and adjacent to the cladding of at least one fuel element so as to impede the flow of the coolant in the vicinity of the cladding and thereby hasten the formation due to heat of a film or layer of steam on its surface. A suitable sensing device is provided to detect the course of this phenomenon which first approaches a dangerous condition at the selected fuel element due to the constricted coolant flow in its vicinity. Accordingly, a hazardous increase in steam-film formation throughout the cooling system due to an excessive temperature difference between the surfaces of fuel elements and the coolant can be detected in advance without requiring the rupture of a single fuel element cladding. (Owens, K.J.)