24 April 2021

What’s next for Chernobyl?

As the 35th anniversary of the failure of a routine test at the Chernobyl Nuclear Power Plant approaches, what lies ahead for the area?

The New Safe Confinement at Chernobyl
The New Safe Confinement at Chernobyl © EBRD

It is time to plan, agree and implement the next phase of work at Chernobyl, Ukraine. The estimated 200 tonnes of radioactive nuclear fuel inside reactor 4 are now shielded by the New Safe Confinement (see History below). However, parts of the sarcophagus are becoming unstable and will have to be removed at some point. Once this is done, work will come closer to the reactor’s interior.

The European Bank for Reconstruction and Development (EBRD) is a key partner in these efforts. Following a request by Ukraine, in November 2020, the Bank established the new International Chernobyl Co-Operation Account, aimed at creating an integrated plan for the site to serve as the basis for developing and implementing longer-term projects. The new fund will hold it first assembly meeting on Tuesday 27 April.

On 26 April 1986, the failure of a routine test at the Chernobyl Nuclear Power Plant in Ukraine, then part of the Soviet Union, caused reactor 4 to explode, releasing parts of its radioactive core. The nuclear accident had far-reaching political, economic and ecological consequences.

Later that day, all fires at the power plant had been extinguished, apart from the fire inside reactor 4, which continued to burn as around 5,000t of boron, dolomite, sand, clay and lead were dropped from helicopters in a bid to extinguish the blaze. When the destroyed reactor was later enclosed in a provisional structure – the sarcophagus – these fuel-containing materials were also walled in.

By November 1986, a steel and concrete shelter was in place to lock away the radioactive substances inside the ruined reactor building and to act as a radiation shield. It was a temporary measure, with an estimated lifespan of 20-30 years.

The search for a long-term solution started soon after, alongside the challenge of cleaning up the accident site. By the end of 1991, a newly independent Ukraine was left with the Chernobyl legacy. Following a G7 Action Plan to improve nuclear safety in central and eastern Europe, the Nuclear Safety Account was set up at the EBRD in 1993. Two years later, the scope of the programme was extended to include Chernobyl.

The Shelter Implementation Plan of 1997 provided a road map of how to the tackle the immediate and longer-term tasks. In the same year, the G7 officially invited the EBRD to set up and manage the Chernobyl Shelter Fund, which became the main vehicle for all efforts to ensure that the destroyed reactor 4 remained in an environmentally safe and secure state.

Emergency repairs in 1998 and 1999 prevented the imminent collapse of the sarcophagus, as well as a vent stack that was endangering the adjacent turbine hall over reactor 3, which was still in operation. It was only at the end of 2000 that all nuclear power generation in Chernobyl ceased. The following year saw the decision to build an arch-shaped steel structure, called the New Safe Confinement (NSC), to seal off reactor 4.

In the subsequent years, several tasks were carried out simultaneously. Detailed technical work on the NSC started. The site had to be stabilised and prepared for the construction work. The first project the EBRD managed was the construction of a liquid radioactive waste treatment plant (LRTP) to handle some 35,000 cubic metres of low- and intermediate-level liquid waste at the site. Meanwhile, the safe storage of the spent fuel assemblies from reactors 1, 2 and 3 came into focus.

All this has been achieved. The LRTP has been operational since 2014. A new interim storage facility for the treatment and storage of spent fuel has been built and, after successful hot tests, is currently awaiting a permanent licence from the Ukrainian regulator. The NSC, the most visible Chernobyl project, was slid into position in late 2016 and then handed over to the Ukrainian authorities.

The NSC dominates the skyline over Chernobyl. The steel structure is 108m high and 162m long, with a span of 257m and a lifetime of 100 years. It was assembled in two stages in a cleaned area near the accident site and, despite its size and weight of 36,000t, was pushed 327m into position. It is the largest moveable structure ever built.

Due to the limited lifetime of the NSC work must continue at the site to make it safe for the long term.