FACTBOX-Plutonium, one of the world's deadliest elements

Thu Oct 15, 2009 1:08pm BST

Oct 15 (Reuters) - France's nuclear safety watchdog said on Thursday it had suspended efforts to dismantle a plutonium technology plant after nearly 3 times the expected levels of the radioactive element were found at the site.

Around eight kilograms of plutonium were believed to have been stored at the site when it was up and running, but some 22 kilograms had been discovered to date and the final figure could be closer to 39 kilograms, the nuclear safety watchdog ASN said.

Following are some facts about Plutonium (Pu), one of the world's most dangerous elements, which is formed in the fuel of nuclear reactors during their operation.


MILITARY USE:

About 6 kilograms of plutonium went into the bomb dropped by the United States on the Japanese city of Nagasaki in 1944 (the bomb dropped on Hiroshima used uranium).


ENERGY USE:

Plutonium is seen as a valuable energy source. According to the International Atomic Energy Agency, generally speaking, one gram of plutonium is equivalent to about one tonne of oil.


SOURCES OF PLUTONIUM:

Spent fuel. Since the end of the Cold War, plutonium has also been released from dismantled nuclear warheads.


WHAT TO DO WITH SURPLUS PLUTONIUM?

-- Burn it: plutonium can be used as fuel in fast reactors. But the construction of such reactors has been delayed due to cost and safety concerns. It is also being used in light-water reactors as mixed-oxide (MOX) fuel, but such fuel will still end up in storage once it is spent.

-- Store it: nuclear waste storage has encountered strong public opposition due to safety and health concerns.


HOW MUCH PLUTONIUM IS THERE?

At the end of 1997, the International Atomic Energy Agency estimated the amount of plutonium stored world-wide as follows:

- About 1,000 tonnes of plutonium from spent fuel from power reactors

- About 170 tonnes of separated plutonium from civilian reprocessing operations

- About 100 tonnes of plutonium from dismantled warheads in Russia and the United States

(Sources: International Atomic Energy Agency, International Energy Agency, Institute for Energy and Environmental Research, Greenpeace, World Information Service on Energy)

(Reporting by Sophie Hardach)