The incoming government immediately announced plans to build new nuclear reactors to meet Sweden's rising electricity needs.

"New nuclear reactors will be built", the leader of the Christian Democrats Ebba Busch told reporters.

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

The outgoing Social Democratic government, in power for the past eight years, has traditionally been opposed to the construction of new reactors but acknowledged earlier this year that nuclear energy would be crucial for the foreseeable future.

Swedish energy group Vattenfall said therefore in June it was examining the possibility of building at least two small modular nuclear reactors (SMRs).

Meanwhile, Kristersson who is expected to become the next prime minister, told reporters the new coalition government would be comprised of the Moderates, Christian Democrats and Liberals, together "cooperating with the Sweden Democrats in parliament".

The speaker of parliament is expected to announce a vote in parliament on Monday on Kristersson as the new prime minister, one month after the right-wing won a narrow victory in a general election, ousting the Social Democrats after eight years in power.

The four right-wing parties together hold 176 of 349 seats in parliament.

The far-right Sweden Democrats, once shunned as pariahs on Sweden's political scene, were the big winners of the September 11 vote.

They emerged as the second largest party with a record 20.5 percent of votes, behind outgoing prime minister Magdalena Andersson's Social Democrats, which have dominated Swedish politics since the 1930s.