'Small nuclear' reactors explained using bags of rice

The future of nuclear power is not with huge plants like Hinkley Point in Somerset, but with mini nuclear reactors, the UK's top energy experts say.

The small reactors can be built in a factory and delivered to site on the back of a lorry.

It is argued that the so-called "plug and play" modular reactors will provide value for money.

But environmentalists are warning that small reactors are not yet built - and won't help in the short term to hit carbon emissions targets.

The BBC's Roger Harrabin Environment and Energy Analyst explains.