Nuclear waste from the reactors likely to be built in the UK will be up to seven times more hazardous than that produced by existing reactors.

The admission was made in an 'environmental impact assessment' report by nuclear company Posiva. Posiva are responsible for managing the waste which will be produced by the European Pressurised Reactor (EPR) currently being constructed in Olkiluoto, Finland.

And an independent nuclear consultant has warned that this will increase the costs of nuclear energy, as waste storage and safety expenses will rise above expected levels.

Normandy in France is the site of the only other EPR being built in the world. It is the design that French government-owned EdF will attempt to build in Britain. Last week, French president Nicolas Sarkozy announced that a second EPR would be constructed in France.

Independent nuclear consultant John Large said: "This means that not only will spent nuclear fuel produced by the EPR be more dangerous than is acknowledged by the French nuclear industry, but also storage and disposal will be more expensive than the industry and governments proclaim, and will increase the overall cost of nuclear energy.

"The French nuclear companies Areva and EDF, which aggressively market the EPR as safe and cheap, have completely ignored the implications of the increased hazards."

The EPR is designed to extract more energy from nuclear fuel than current nuclear reactors. But this causes the amount of radioactive substances in spent fuel to increase disproportionately. If the fuel is disposed of by burying it in an underground nuclear waste dump, in the long-term, the largest health risk comes from a hazardous substance known as iodine-129. The amount of iodine-129 produced by the EPR is seven times as large as that of a current operating reactor.

Nathan Argent, head of Greenpeace's energy solutions unit, said: "Nuclear power is fast becoming the most expensive form of electricity, and revelations like this should be cause for alarm amongst both investors and taxpayers.

"Instead of being hoodwinked by the vacuous promises of the nuclear lobby, government and industry should instead be making a clever investment in energy efficiency. This would create tens of thousands of British jobs, and also tackle fuel poverty and climate change in the fastest possible way."

ENDS

The full Posiva report is available online - the relevant information is on page 137.

Greenpeace press office: 020 7865 8255.