Chernobyl new safe confinement

How can the Chernobyl site be cleaned up in complete safety? Our team of engineers devised a prototype arch to confine, sort, store, and stockpile radioactive waste materials – while ensuring maximum protection for workers on site. The arch-shaped confinement structure designed to enable the dismantling of the old sarcophagus and the remains of the damaged reactor consists of a metal frame weighing 36,000 tonnes (fully equipped), measuring 105 metres in height and 150 metres in length, with a span of 257 metres. The structure is large enough to cover the Stade de France or the Statue of Liberty or the ground around the Eiffel Tower. The arch is as tall as a 30-storey building.


Following the explosion on April 26, 1986 of reactor number 4 of the Chernobyl nuclear power plant, Ukraine launched a design contest for a confinement shelter to isolate the nuclear reactor and minimise all potential risk.
The contest was won by a European consortium led by Campenon Bernard SGE (VINCI Construction). The strength of our proposal was that we would design and implement a structure to confine, sort, and store short-lived radioactive waste and stockpile non-disposable waste.
The contract was signed on September 17, 2007 with the NOVARKA consortium led by VINCI Construction Grands Projets; and work began in 2010.


The foundations were built with 400 piles that are one metre in diameter and 19 metres deep. These were located in proximity to the sarcophagus where concrete beams designed to support the arch in its final position were built. The weight of the arch was to be distributed evenly on these two concrete beams, thereby providing support for the considerable mechanical forces exerted by the structure.
Protection from radioactivity was a key requirement in developing construction methods for the project. Since exposure is lower at ground level, ground-level works were preferred to construction tasks at height. Consequently, the first half of the arch was assembled on the ground just west of the damaged reactor and raised in three successive lifting operations. The same process was used to assemble and raise the second half of the arch. The two arches were then literally bolted together using 600,000 bolts, measuring 15 cm in length and weighing more than 1 kg each, to create an unprecedented structure.
The confinement arch is equipped with devices and systems designed for the dismantling of reactor number 4. This future operation can be carried out in the best conditions in terms of flexibility and safety, while minimising direct human intervention.
The arch is designed to withstand temperatures ranging from minus 43°C to plus 45°C, but also a Class 3 tornado (which occurs once every million years) and an earthquake measuring 6 on the Mercalli scale (which occurs once every 10,000 years).
All precautions were taken during the construction phase of this structure to ensure maximum safety.

“We maximised the amount of work carried out far from the reactor in efforts to protect our teams from radiation, while building the most effective confinement structure possible.”
Marc Wastiaux, in charge of designing this prototype at VINCI Construction Grands Projets, and Technical Director of the NOVARKA consortium


Since the worksite was in a high-risk location, the main challenge was to deliver a certain level of quality while ensuring maximum safety. That is why design and construction were governed by the ALARA (As Low As Reasonably Achievable) principle. This principle is an extension of the precautionary principle applied in the field of radiation protection: individuals working with toxic hazards cannot be exposed beyond a set maximum dose. Consequently, for certain tasks, especially in close proximity to the sarcophagus, personnel must work behind concrete or lead screens. The arch-assembly and lifting areas were decontaminated, and workers wear protective clothing. A team of 60 people is entrusted with the task of protecting employees from radiation.
To carry out this unprecedented project, we had to recruit talent from around the world: more than 25 nationalities are present on a permanent basis at the worksite. As a result, the project also required considerable multicultural management skills.

Project participants


Project management
Project Management Unit (Bechtel, EdF, ChNPP)


Key figures

Implementation dates
October 2007 to November 2017

Span of the arch
257 m

108 m

162 m