Mini nuclear plants to power 20,000 homes £13m shed-size reactors will be delivered by lorry * John Vidal and Nick Rosen

Nuclear power plants smaller than a garden shed and able to power 20,000 homes will be on sale within five years, say scientists at Los Alamos, the US government laboratory which developed the first atomic bomb.

The miniature reactors will be factory-sealed, contain no weapons-grade material, have no moving parts and will be nearly impossible to steal because they will be encased in concrete and buried underground.

The US government has licensed the technology to Hyperion, a New Mexico-based company which said last week that it has taken its first firm orders and plans to start mass production within five years. 'Our goal is to generate electricity for 10 cents a watt anywhere in the world,' said John Deal, chief executive of Hyperion. 'They will cost approximately $25m [£13m] each. For a community with 10,000 households, that is a very affordable $250 per home.'

Deal claims to have more than 100 firm orders, largely from the oil and electricity industries, but says the company is also targeting developing countries and isolated communities. 'It's leapfrog technology,' he said.

The company plans to set up three factories to produce 4,000 plants between 2013 and 2023. 'We already have a pipeline for 100 reactors, and we are taking our time to tool up to mass-produce this reactor.'