The first plutonium 238 production since the Cold War is being mooted by the USA as part of a programme of covert and aeronautical missions.

Officials behind the plan indicate that the programme would produce a total of 150kg of the material over 30 years at the Idaho National Laboratory. Costs of the programme are estimated at up to $1.5 billion and while details have not been disclosed suggestions have been made that the material would probably be used to power devices for conducting espionage and as an energy source for spacecraft.

With existing supplies of the material expected to last only another five years or so, a final decision is expected later this year by energy secretary Samuel Bodman. If approved, the new complex is expected to be finished by 2009 and cost as much as $300 million. Plans call for making around 5kg of plutonium 238 a year.