IN-CORE INSTRUMENT(ICI) GUIDE STRUCTURE FOR THE TOP MOUNTED ICI SYSTEM

摘要

PURPOSE: An in-core instrument(ICI) guide structure for a top mounted ICI system is provided to prevent overheat at the core of a nuclear reactor by inserting in-core instrument through an upper cover. CONSTITUTION: A nozzle of a measurement unit(40) is penetrated through an upper cover and is fixed to the upper cover. A guide pipe(30) of the measurement unit has a hollow for guiding the measurement unit therein. The guid pipe of the measurement unit is extended to inside a nuclear fuel assembly. A structure(50) for supporting the measurement unit is interposed between an upper and a lower cover of the nuclear reactor. A control rod driving system(27) is included in the central of the upper cover of the nuclear reactor.