Method and apparatus to shield a nuclear fuel assembly with a removable debris shield in an upper tie plate

摘要

A method to clean or replace a debris shield in a nuclear reactor fuel bundle assembly (10), wherein the fuel bundle assembly includes a bundle of fuel rods (11, 12) in which the fuel enriched portions of the rods are below an upper tie plate (13, 100, 130, 150) and housed in a channel (20), the method comprising: inserting a debris shield (102, 136, 152, 168) in the upper tie plate; maintaining the shield in the upper tie plate and above the fuel enriched portions of the fuel rods, while the fuel assembly is in an operating nuclear reactor core (21); flowing coolant through the bundle and the debris shield during operation of the nuclear reactor core; capturing or deflecting debris flowing through the fuel bundle assembly with the debris shield; removing the fuel bundle assembly from the nuclear reactor core, and removing the debris shield from the upper tie plate.