01 Feb An extended arm in the water

The team in charge of dismantling research reactor Dr 3 should not only concentrate on breaking down the reactor block itself, but also take care of all the elements that have been included in the trials. A basin plays an important role here.

N Some of the employees have recently been emptying two storage blocks – one right next to the reactor block and one in an adjacent hall – from pipes. These are about 200 pipes that have been used in various ways while the reactor was running.

40 of the pipes are the so-called Flux Scan Absorbers. They have been placed inside the fuel element tubes to regulate fission, so they must be treated particularly carefully.

The team has carefully removed the 'absorbers' themselves (thin steel rods that have absorbed neutrons) from the aluminium tubes that have enclosed them. Then the steel rods are transferred to a large basin, where they are now cut into smaller pieces, one by one. The nearly 5 meter deep basin has over time been used both for the storage and treatment of irradiated elements, as water shields from radiation.

A remote-controlled giant scissors are placed on the bottom of the basin. A research technician slowly lowers the string with the steel rod with one hand and steers the giant scissors with the other hand. Slowly but surely, the steel rod is turned into a pile of 15 cm long pieces.

The research technician then grabs a long rod with mechanical fingers at the end. With his extended arm, he now picks up each piece on the bottom of the pool and lifts it through the water into a metal basket. When all 40 absorbers lie like pieces in the basket, the basket is lifted up with a lead-lined transport container and transferred after draining to a shielded container.

To minimize radiation risk, a health assistant continuously monitors all work processes.