Chernobyl new safe confinement


Duration:6 years


Country: Chernobyl, Ukraine

What did this project achieve?

Place a protective structure around the huge nuclear reactor at Chernobyl

The worst nuclear accident in history happened at the Chernobyl power plant in Ukraine in April 1986.

Design flaws and operator mistakes combined to cause a steam explosion in reactor number 4 leading to a fire that burned for 9 days. This threw radioactive waste into the atmosphere which drifted across the Soviet Union and Europe.

2 workers died in the initial blast. 28 workers and firemen died from radiation in the following weeks and months. Up to 30 cancer deaths have been linked to the accident with around 4,000 more predicted.

A concrete structure known as the sarcophagus was hastily constructed around reactor number 4 in the months after the accident to contain the radioactive remains.

Never intended to be permanent, the sarcophagus deteriorated over the years and become less effective.

Work started on a new safe confinement (NSC) for reactor number 4 in 2010.

The structure – looking like a giant aircraft hangar – was designed to enclose and seal off the reactor and sarcophagus for at least a century.

Difference the nuclear confinement has made

The Chernobyl NSC is primarily a nuclear entombment device – a structure that contains nuclear waste until it is no longer dangerous.

Designed to last 100 years, it should help contain and reduce future radioactive contamination.

How the work was done

Engineers designed the NSC to prevent the release of contaminated material into the atmosphere and protect the reactor from severe weather.

The structure's frame is made up of lengths of tubular steel supported by concrete beams. It's 108m high and 162m long with a span of 257m.

Engineers built the NSC to one side of the reactor and then slid it over the sarcophagus using rails and hydraulic jacks.

It took from 14 November to 29 November 2016 – 15 days – to move it into place.

The NSC is part of the 'shelter implementation plan' which is set to finish in 2018.


A monster cage to contain the beast.

From the EBRD's 'Transforming Chernobyl'

Fascinating facts

The Chernobyl NSC is tall enough to slide over St Paul's Cathedral in London or Notre Dame Cathedral in Paris.

The NSC's metal frame weighs 25,000 tonnes – about the same as 3 Eiffel Towers.

Built against extreme temperatures (from -43 to +45 degrees C), the structure can also resist a category 3 tornado - that's windspeeds of 254 to 332kmph.

People who made it happen

  • Client: government of Ukraine
  • Main contractors: Novarka, Vinci Construction, Bouygues S.A.
  • Finance: the European Bank for Reconstruction and Development (EBRD)

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