01 Mar Reactor's internal parts are gone

Around the innermost tank of Danish Reactor 3 has sat a graphite reference that shot back the neutrons. The reflector and an associated layer of lead are now gone. This completes the remotely operated cutting of the internal parts of the reactor.

D For the past two years, a control car at the bottom of the reactor building has been manned by two craftsmen who have painstakingly removed the inner parts of the reactor, bit by bit. Thomas Nielsen and Rune Duelund Nielsen have been the primary forces on the task.

In 2017, they cut up the inner aluminium tank using a plasma cutter mounted on a mechanical arm. Each bit of the tank was gripped by a hydraulic claw, lifted up into a packing room on top of the reactor and carefully placed in a container.

The next step was to remove the surrounding graphite reflector, put together by 685 bricks. That's most of 2018. The first task was to break up a brick in the upper ring of graphite blocks; here a self-developed saw was used mounted on the mechanical arm. Then the other bricks of the ring could be lifted out relatively easily with a powerful vacuum suction. So you worked your way down, call by ring.

The big challenge has been the layer at the bottom. Here the bricks were wedged so close together that they had to be drilled, pressed, wiggled and pryed to get them wrestled apart. It required frequent tool changes. When the last block was lifted away, a remote-controlled broom, sweeper and vacuum cleaner came into swing to remove all the crumble.

As 2018 drew to a close, the mechanical arm went about its final task: peeling away the layer of lead behind the bricks with a crowbar. It succeeded, too, and DD's temporary storage facility is now home to seven containers of graphite bricks and one container of the lead layer.

The control truck, packing room and other equipment used to remove the internal parts of the reactor have thus played their part and will be removed. Next, the cutting of the outer parts of the reactor, mainly large amounts of concrete, awaits.

(NB. The video is without sound.)