International heavy lift company Mammoet and its client Novarka have successfully connected the two halves of the New Safe Confinement (NSC) structure at the Chernobyl Nuclear Power Plant in Ukraine. This was needed following the catastrophic nuclear accident in 1986.
The two halves of the arch were built in a decontaminated area away from damaged reactor Unit 4 and have now been joined so that the structure is ready to be placed over the existing limited life sarcophagus built as emergency protection in the immediate aftermath. The skidding of the NSC to its final position is planned for late 2016.
Once the arch is placed over the reactor building it will provide a controlled, weatherproof environment and confinement for the solid radioactive remains of the reactor for the next 100 years. This will allow partial deconstruction of the old plant to be carried out in the future.
Weighing 19,000 tonnes, with a span of 260 metres, length of 80 metres and height of 110 metres, the east arch section was skidded to a waiting area in November 2014 to await completion of the second half of the arch.
To move and join the two halves of the arch, Mammoet developed and built a fully remote-controlled skidding system using total of 56 skid shoes, each with a minimum capacity of 703 tonnes. The remote control is necessary to allow the operator to control the procedure to lift, shift and move the load into place over the sarcophagus from outside the contaminated area. The operation to join the two halves - completed last month - took less than six hours and required extreme precision with alignment tolerances of only three millimetres.
Novarka is currently working on the tightening of about 1,000 bolts to connect the two halves of the arch. When securely joined, the NSC will have a length of 165 metres and will weigh more than 35,000 tonnes. The skidding of the NSC to its final position, over the original sarcophagus, is planned for the fourth quarter 2016. For this operation a total of 116 skid shoes will be required. It is estimated it will take about a week to skid the arch over a distance of 330 metres.
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