Some 40 countries, including the five big nuclear weapons states, have signed a nuclear safety document designed to step up security at atomic reactors worldwide, U.N. officials said Wednesday.
Members of the International Atomic Energy Agency began signing the safety agreement Tuesday, led by the United States, Russia, China, France and Britain.Officials at the Vienna-based IAEA, the nuclear arm of the United Nations, said enough countries had now signed the International Convention on Nuclear Safety to bring it officially into force.
National parliaments also have to ratify the document.
The convention applies to land-based civil nuclear power plants and seeks to avert accidents such as the 1986 explosion at Cher- nobyl, the world's worst civil nuclear disaster.
Ukraine, which now owns Chernobyl following the collapse of the Soviet Union, signed the convention Tuesday.
Work on the convention began in 1991 after communism crumbled in Eastern Europe and the Soviet Union, revealing potential safety risks posed by the region's aging reactors.
Bulgaria, which has also signed the convention, shut down two of six reactors at its Soviet-designed Kozloduy plant on the Danube in 1991 due to international safety concerns.
Signatories are required to submit an immediate report on atomic installations and, if necessary, urgently carry out improvements to upgrade the safety of sites.
A key demand in the document urges countries to shut down reactors if they have tried all other means to improve safety.
The document sets out a framework for a review of a nation's atomic sites by other countries.
Neighboring states, in particular, may call for an urgent study if they are concerned about a reactor's safety and a possible radioactive fallout accident affecting their own populations and crops.