(Reuters) - A quarter of a century since the meltdown at Ukraine’s Chernobyl power plant, the international community is still trying to secure funds to make the site of the world’s worst nuclear accident safe.
A makeshift shelter over the damaged reactor erected hastily in the aftermath of the disaster is to be reinforced with a new shell as high as the Statue of Liberty and almost three times as heavy as the Eiffel Tower, while a new storage facility for the decommissioning of spent fuels will also be built.
Here are some facts about the security measures planned and why they are needed:
After Chernobyl’s No. 4 reactor exploded on April 26, 1986, a “sarcophagus” was built over a period of six months as a temporary measure to stop radiation from spreading, with workers often putting their life at risk to complete it.
Experts say a new environmentally sustainable shelter is needed to ensure that water and snow never enter and degrade the sarcophagus and that contaminated dust does not spread from the site. It will also facilitate the deconstruction of the reactor.
The new shelter, dubbed the New Safe Confinement (NSC), will have a span of 257 metres, a length of 164 metres, a height of 110 metres and a weight of 29,000 tons. It will cost close to 1 billion euros and have a life span of at least 100 years.
The structure is based on huge lattice of tubular steel members built on two concrete beams. It will be assembled on site, 250 metres away from the highly radioactive No.4 reactor, and then slid into place, engulfing the reactor building.
A consortium called Novarka, comprising French construction conglomerates Vinci and Bouygues, has been awarded the contract for the design and construction of the project.
Piling for the foundations and the lifting cranes required started in September 2010. According to the latest schedule, the NSC will be completed in the summer of 2015.
Spent nuclear fuel from the time Chernobyl was operational is being stored in a wet storage facility constructed in Soviet times, whose licence is unlikely to be extended when it expires in 2016, and in pools in reactors, preventing decommissioning.
A new facility, the Interim Storage Facility 2 (ISF-2), will provide dry storage for the more than 20,000 spent fuel assemblies in the plant for a period of at least 100 years.
Processing at the site will involve cutting, drying and fitting of spent fuel into storage containers. The project is expected to cost around 250 million euros and be ready by 2015.
The contract to design and complete the facility was awarded to U.S. energy technology company Holtec International.
Source: European Bank for Reconstruction and Development
Reporting by Greg Roumeliotis