21.   The radioactive plutonium at the core of a nuclear weapon has a half-lifemeasured in hundreds of years.

22.   Three hours of nuclear tension gripped Australia on Monday with the country put on full alert to brace for a rogue Russian space probe carrying radioactive plutonium.

23.   The United States said late Sunday that a disabled Russian space probe carrying radioactive plutonium was expected to hit central to eastern Australia within hours.