I don't know this plant. In navy submarine reactors like the S5W, you have 440V/3-phase power holding the clamp. If you dropped a rod due to a power or clamp malfunction, usually you'd simply shut down the reactor, drop all the rods and mechanically re-engage the clamp. It could take a few hours which isn't fun because no power which probably means submarine/snorkel depth to run the incredibly noisy diesel, but no step was particularly hard or dangerous.