Power group Vattenfall believes it will take several years before a decision can be made to build another Swedish nuclear reactor, the head of its nuclear operations told a newspaper on Thursday.

"We're working with the aim of being able to replace one of reactors that will be taken out of service in the 2020s," Torbjoern Wahlborg told business daily Dagens Industri.

However, a decision on the matter could take up to ten years, he added.

Building a reactor would cost around 60 billion kronor (7 billion euros, $9 billion). "It's a huge project where the economic and political circumstances both have to be right," he said.

Defending the future of the industry, Wahlborg said: "Nuclear energy gives large amounts of electricity with the crucial advantage that it's climate neutral."

The Swedish parliament voted in June 2010 to authorise the replacement of the country's nuclear reactors.

Two years later, Vattenfall asked the Swedish regulator to evaluate the conditions for replacing the group's seven reactors, which will begin to shutter in the second half of the 2020s.

Vattenfall operates two out of three nuclear power plants in Sweden, where atomic power accounts for 35 percent of all electricity production.