NUCLEAR FUEL TOP NOZZLE HAVING IN-CORE INSTRUMENT INSERTION STRUCTURE USING UPPER CORE PLATE GUIDE PIN

摘要

The present invention relates to a top nozzle and a reactor in which a reactor top head penetrating type in-core instrument is inserted using an upper core plate guide pin. In a reactor comprising a guide pin for aligning a top nozzle of a nuclear fuel assembly and an upper core plate of the reactor, a guide hole (210) is formed to penetrate through the guide pin (200) in an axial direction, and an in-core instrument (10) is inserted along the guide hole (210).