Chernobyl Nuclear Power Plant Decommissioning, Ukraine

On April 26th, 1986, the Chernobyl nuclear power plant's number four reactor exploded, sending a radioactive cloud across much of Europe. Following the explosion, radioactivity with an intensity equivalent to 500 of the bombs that destroyed Hiroshima at the end of World War II was measured in the atmosphere.

In 2005, the IAEA (International Atomic Energy Agency) and WHO (World Health Organization) reported that only 56 people had died directly from the incident, mainly accident workers. They estimated another 4,000 deaths among workers and local residents.

According to unofficial statistics, though, at least 15,000 people have died as a direct result of the explosion. The power station is still seen by critics as a time bomb, and work has been carried out ever since to try and make the site safe.

CHERNOBYL CLOSURE AND CONSTRUCTION

The work that has been carried out has been considered unsatisfactory by the West. Chernobyl still operated for some time afterwards (there was not enough generating capacity in the Ukraine for its closure) and countless, more minor, incidents occurred since 1986.

After a 1991 fire in Reactor 2, this reactor was taken offline, and decommissioned in 1996. Reactor 3 was switched off in 2000 to close the plant. In early 2002 the European Commission paid the first installment of its promised €40m additional Shelter Fund. The fund was paid in four installments from 2001–2004. It helped to support the decommissioning work at the site.

PROJECT MAKE-UP: DECOMMISSIONING

Following the 1986 accident the number four reactor at Chernobyl was encased in a giant concrete 'sarcophagus' to prevent further leakage of radioactive material. Hundreds of thousands of mobilised soldiers and civilian experts constructed the sarcophagus above the destroyed reactor, and the plant was re-opened in late 1986. A huge fire in the second reactor led to its closure in 1991, and in 1996, the number one reactor was shut down as it had reached the end of its life-span.

The sarcophagus built in 1986 is considered to be unstable and needs further repair work. In December 2000 the US promised to contribute the largest G7 amount to repair the sarcophagus. A waste management facility began construction in 2001 for the treatment of fuel and other wastes from decommissioned units 1–3. A stabilising steel structure was extended in December 2006 to spread some of the load on the walls damaged by the explosion.

The fuel mass at the reactor has also been enclosed in EKOR, a radiation-resistant material developed by Eurotech Ltd of the UK. The material was applied during March 2000 and is maintaining an isolation coating and seal of the pile, preventing further dusting and leaching of contamination to the environment.

After two months EKOR exceeded the longevity of all previously applied materials, which degraded rapidly in the severe-radiation environment and lost isolation effectiveness.

The EKOR-encapsulated fuel pile has radiation readings in the range of 1,000 rads on contact, although EKOR has been laboratory tested to an accumulated dose of 10 gigarads without loss of physical properties.

In June 1999 ChNPP and a consortium led by Framatone signed a contract to build a facility to store spent fuel. In August 1999 ChNPP signed an agreement with a consortium led by Belgatom for a Liquid Radwaste Treatment Plant (LRTP). A steel casing is now being built over the reactor. French firm Novarka is building the casing, costing $1.4bn. After that, Reactor 4 will be dismantled.