Britain last year backed a $546 million funding round at the company to develop the country's first small modular nuclear reactor (SMR), part of its drive to reach net zero carbon emissions and promote new technology with export potential..

Energy minister Kwasi Kwarteng has also said new nuclear projects will play an important part in Britain's efforts to reduce its reliance on expensive gas, which hit fresh record high prices on Monday amid the crisis in Ukraine.

SMRs can be made in factories, with parts small enough to be transported on trucks and barges and assembled more quickly and cheaply than large-scale reactors.

Each mini plant can power around one million homes and Rolls-Royce has forecast the SMR business could create up to 40,000 jobs based on British and export demand.

Britain's Office for Nuclear Regulation (ONR) said it had been asked to begin a Generic Design Assessment (GDA) for Rolls-Royce SMR Ltd's 470 megawatt SMR design.

"The assessment will begin once the necessary arrangements around timescales and resources have been put in place," the ONR said in a statement.

A GDA is the formal process for approving a new nuclear reactor. This is the first time a small scale reactor has been assessed by regulator.

The process typically takes around 4-5 years for large scale reactor designs.

(Reporting by Susanna Twidale; Editing by Mark Potter)

By Susanna Twidale