The 'critical mass' of uranium-235 or plutonium-239
required for explosive fission is about 5kg.
One half-life of plutonium-239
, a variant of the radioactive element, is estimated at 24,000 years.
Five soil samples, collected at distances between 500 and 1 000 metres from the exhaust stack of Unit 1 and 2 of the Fukushima Nuclear Power Plant on 21 and 22 March, were analysed for plutonium-238 and for the sum of plutonium-239
Some neutrons collide with U-238, producing plutonium-239
and more energy to create heat, which generates steam that turns a turbine and produces electricity.
5 lb) of plutonium-239
a year by 2014, after which it could produce one atomic bomb per year.
Bomb: Codenamed Fat Man, it was made mainly of plutonium-239
and created a 21-kiloton blast.
A Congressional Research Service report on the threat pointed out that dirty bomb components are easier to detect than biological, chemical and even weapons-grade nuclear materials such as highly enriched uranium or plutonium-239
The committee has drafted plans for consolidating and disposing of plutonium-239
and for disposing of uranium-233.
exposed in various capacities to neptunium-237 and plutonium-239
She presents a carefully researched and well-written travelogue that allows the reader to feel the atmosphere in what has become Europe's largest wildlife sanctuary, with wild boars and other endangered species living in the forests, fields and swamps, despite the contamination with cesium-137, strontium-90 and plutonium-239
A reactor core full of spent fuel may contain dozens of kilograms of U-235, and several kilograms of plutonium-239
The half-life of Plutonium-239
, as given in the Merck Index, is 24,110 years.