Britain wants to boost investment in nuclear energy by launching a competition for small modular reactors (SMRs), like those being built by Rolls-Royce, and funding if the technology proves viable. The British government aims to replace aging nuclear power plants, as all but one of the plants are due to close by 2030. Nuclear generates around 13% of the country’s electricity. Large-scale nuclear projects with huge up-front costs have struggled to attract investment, putting the focus on smaller, cheaper reactors.

“I am launching the first competition for Small Modular Reactors,” British Finance Minister Hunt said in his budget statement on Wednesday.

“It will be completed by the end of this year and if demonstrated to be viable we will co-fund this exciting new technology.”

Britain previously announced a competition for SMRs in the 2015 Autumn Statement with the first phase opening in 2016 and attracting interest from 33 eligible parties.

It closed in 2017 without moving beyond the initial, information gathering first stage.

Last year the government committed £210 million to Rolls-Royce for its £500 million SMR programme, which could see the company open factories to build the reactors in Britain.

“Rolls-Royce SMR has called for rapid progress from the Government and we welcome the adoption of that principle in this process,” CEO of Rolls-Royce SMR Samson said in a statement.

In the budget, Hunt also said he would consult on classing nuclear power as “environmentally sustainable” to encourage more private investment into the sector.