June 23rd See the promise of the reactor plug

In May 2014, Danish Decommissioning carried out a major operation: lifting the 22-tonne metal plug from Denmark's largest research reactor DR3. The actual lifting of the plug took an hour, and the operation can be seen in timelapse here.

L The lift of the reactor's plug or top shield plug had been detailed and prepared over several years. First, the reactor top was cleared; metal parts were sawn down and concrete elements were drilled and chopped away. See the process of preparatory work.

Next, the top was cast smoothly and rails were laid down to the moving lid to cover the highly radioactive reactor tank when the stopper was lifted up.

Then came the Dutch heavyweight lifting company Mammoet and built a crane in assembly kits on the outside of it all, so that there were rails in the floor where the moving lid was to run, and at the height at which the lifting crane was to run.

A round shield was placed exactly around the stopper so that it was lifted straight into the guard. Then a red lifting bracket was turned into the top of the stopper and connected to a huge wire game on the crane at height. The entire operating area was wrapped in a two metre concrete wall to shield against the heavy radiation, and the double bottom and lid of the guard were prepared.

The entire reactor hall and surrounding buildings were cordoned off and only the few employees who had to remotely lift the lift from the bottom of the reactor hall were admitted.

The plug was lifted up and the moving lid with concrete wall was immediately rolled over the reactor tank. On the moving lid, the guard to the stopper was ready.

Watch the timelapse: