The design for the first UK nuclear power stations to be built for 25 years will be granted approval later, according to BBC News.

After a five year process, regulators have said the European Pressurised Reactor (EPR), designed by two French firms, is safe and environmentally sound.

But there are still a number of hurdles to be cleared before energy supplier EDF and the nuclear engineering firm Areva can begin construction.

The firms are weighing up the economic case amid concerns about rising costs. The French companies are looking at building two new plants at Hinckley Point in Somerset, but will need planning permission.

The design has already been used for new reactors in Finland, France and China. But construction has taken longer than planned and costs continue to mount.

Last month, EDF revealed that the cost of its Flamanville EPR plant in Normandy had risen by more than 2bn euros (£1.8bn) due to design changes following the Fukushima nuclear disaster in Japan.

Last year, the UK regulators gave interim approval to the EPR under a process called the Generic Design Assessment, which aims to cut costs by examining new nuclear plans on paper rather than during the construction process.

But they said 31 issues must be addressed before approval could be granted. As a result, there have been changes to the design, some of them due to lessons learnt from the Fukushima disaster.

That led to 16 changes, including additional flood protection measures and the provision of mobile generators and pumping equipment.

The regulators said the UK EPR was now "the most-assessed design ever" after a process costing £35m.

EDF has still to confirm that it will go ahead with the investment in the new plan on its existing site in Somerset, to be known as Hinckley Point C.

A decision had been promised by the end of 2012, but the company has now revised that to "the earliest possible date".