An important report assessing the viability of new “mini” nuclear power plants for the UK to be published this week is expected to give the green light to develop designs proposed by a British consortium led by Rolls-Royce.

The Department for Business, Energy and Industrial Strategy (BEIS) is set to issue a study which formally ends a competition between different types of low-carbon power generation to assess which should be supported.

Industry sources say a concurrent Techno-Economic Assessment for the government by EY concludes that designs for small nuclear reactors (SMRs) from the Rolls consortium are the more likely to succeed.

It is understood that rival proposals using US designs for “integral reactors” have been assessed as being harder to manufacture and maintain and not commercially viable.

A different concept from the Rolls consortium - which helped invent the integrated design in the 1980s but abandoned it for similar reasons in favour of a different concept - is expected to get the nod for development from BEIS.

A fleet of these SMRs could be cheaply produced to guarantee Britain’s energy supply, with hopes that the technology could be exported worldwide.

SMRs are a fraction of the size and cost of conventional nuclear plants. They are likely to be funded from the £250m pledged by the Government in 2015 to develop “innovative nuclear technologies” which would help the country hit climate change targets.