Under a contract signed on February 10 between Atomstroyexport and the state-run Ukrainian company that supervises work on the plant, the former is to repair and reinforce the badly-worn cover of the Chernobyl shelter.
The work to repair the shelter will be paid for by the international Chernobyl Shelter Fund. The fund comprises 28 countries, including the G8 nations, and is run by the European Bank for Reconstruction and Development.
In September 2007, Ukraine signed a contract with France's Novarka to build a new shelter over the damaged reactor and also a deal to build a "dry storage" facility for spent nuclear fuel on the site of the plant with the U.S. company Holtec International.
Construction of the new $1.2 billion shelter is due to start this spring. It will be constructed on site and then slid over the reactor.
Chernobyl was the site of the world's worst nuclear accident. On April 26, 1986, reactor number four at the Chernobyl Nuclear Power Plant exploded, resulting in a critical nuclear meltdown.
Vast areas, mainly in the three then-Soviet republics of Ukraine, Belarus and Russia, were contaminated by the fallout of the explosion. More than 300,000 people were relocated after the accident. However, 5 million people still live in areas of Belarus, Russia and Ukraine classified as "contaminated" by radioactive elements.
Estimates by international bodies as to the number of deaths caused by the accident at Chernobyl vary dramatically. Fifty-six people were reported to have been killed at the scene of the disaster, and another 4,000 to have died of thyroid cancer shortly afterwards. Several million more people are believed to have been exposed to different degrees of radiation.
The disaster is thought to have released at least 100 times more radiation than the atom bombs dropped on the Japanese cities of Nagasaki and Hiroshima in WWII.
Soviet authorities initially attempted to cover up both the scale of the accident and its consequences.