Four decades after Swedes voted to phase out nuclear power, the state-owned company said it would conduct a pilot study to examine the conditions for building two SMRs adjacent to the Ringhals nuclear power plant on the country's southwestern coast.

It said it hoped to have a first one operational by the early 2030s.

"We will need all fossil-free energy sources to meet the increasing demand for electricity in Sweden," Vattenfall's chief executive Anna Borg said in a statement.

Energy prices have soared in Sweden following the Covid pandemic and Western sanctions against Russia over Ukraine.

The Scandinavian country voted in a 1980 non-binding referendum to phase out nuclear power.

Since then, Sweden has shut down six of its 12 reactors and the remaining ones, at three nuclear power plants, generate about 30 percent of the electricity used in the country today.

But Sweden has struggled to find viable alternative energy sources to replace its nuclear power, with renewable energies not yet able to fully meet its needs.

In 2016, a broad political majority agreed to extend nuclear power for the forseeable future, paving the way for new reactors to be built to replace the ageing ones at the end of their lifespans.

The reactors were opened in the 1970s and 1980s. Most of them have lifespans of around 40 years and are in need of modernisation.

Sweden's ruling Social Democrats have traditionally been opposed to building new reactors, while the centre-right opposition has been in favour.

But last week, Energy Minister Khashayar Farmanbar acknowledged that nuclear energy would "be crucial for a long time ahead".

"It is therefore important to continue to develop nuclear power", he said.

SMRs are advanced nuclear reactors that have a power capacity of up to 300 MW(e) per unit, which is about one-third of the generating capacity of traditional nuclear power reactors.

They are relatively simple to build, as their systems and components can be factory-assembled and transported as a unit to a location for installation, which also makes them more affordable than large power reactors.