BWR nuclear fuel assembly comprising an interaction device between a lower tie plate and a fuel channel

A fuel assembly for a boiling water reactor, the fuel assembly being elongated along a fuel assembly axis, the fuel assembly comprising:

• a lower tie plate;
• an upper tie plate axially spaced from the lower tie plate;
• a bundle of fuel rods extending axially between the lower tie plate and the upper tie plate;
• a tubular fuel channel extending from the lower tie plate to the upper tie plate and encasing the fuel rods;
• and
• an interaction device mounted on the lower tie plate and configured to interact with the fuel channel,
• wherein the interaction device is operable with a tool to switch between an inactive configuration and an active configuration;
• wherein the interaction device comprises an interaction member that is movably mounted on the lower tie plate between an inactive position in which the lower tie plate is liftable upward relative to the fuel channel and an active position in which the lower tie plate is locked to the fuel channel by the interaction member;
• wherein the interaction device comprises a return member configured for urging the interaction member from the inactive position to the active position;
• wherein the interaction device comprises a retaining mechanism configured for retaining the interaction member in the inactive position;
• wherein the retaining mechanism comprises an helical slot provided on one of the interaction member and the lower tie plate, and a retaining member provided on the other one of the interaction member and the lower tie plate, the retaining member for engaging into the helical slot, the retaining member being in the helical slot in the active position.