A steel arch weighing 3800 tonnes is being lifted at the Chernobyl site in Ukraine, the second such milestone for the New Safe Confinement project.
When complete the NSC will cover the broken reactor building of Chernobyl 4 as well as its 'sarcophagus' shelter. Airtight to protect the environment from radioactive dust within, it will contain remote handling equipment that will enable engineers to eventually dismantle the remains of the reactor.
The new arch was made in segments, now put together, and today is set to be lifted to a height of 12 meters. Tomorrow it will be raised a further 21 meters, and eventually to a height of 85 meters.
|Workers walk among the red beams of the arch and the white columns that will support it when raised (Image: Chernobyl NPP)
The NSC will be assembled in two halves, each comprising several of these arch sections. The first half will be completed and then pushed into a holding area in front of unit 4 while the second half is assembled. The two sections will then be joined together by the end of 2014 and fitted with cladding, cranes and remote handling equipment during 2015.
The entire completed structure - weighing some 31,000 tonnes - will be pushed over unit 4 and part of its turbine hall using hydraulic jacks in a three-day sliding operation scheduled before the end of 2015. End walls will then be built to strengthen and seal the NSC, creating a means of confining dust and debris from dismantlement while protecting it from harsh weather. However, the structure is not designed for radiation shielding: gamma radiation doses outside of the NSC will be about the same as they are now.
Researched and written
by World Nuclear News