Sweden’s government on June 10 struck a deal with the opposition to continue nuclear power for the foreseeable future, reversing an earlier nuclear phase out policy. The government coalition, comprising Social Democrats and the Greens, had agreed in October 2014 to freeze nuclear energy development, while the opposition has been in favour of building new reactors. The new arrangement is aimed at securing long-term energy supplies to households and industry, the government said. "Sweden shall have a robust electricity system with a high level of secure supply, low environmental impact and energy at competitive prices," the agreement said.

The agreement opens the way for the construction of new reactors to replace those reaching the end of their service life. "Permission may be granted to successively replace existing reactors as they reach the end of their economic lifespans," the agreement noted. Sweden has already shut down three of its reactors – one at Oskarshamn NPP, which is due to be decommissioned between 2017 and 2019, and two at Ringhals NPP, due to be decommissioned in 2018 and 2020.

There are currently nine operating reactors at three NPPs, which generate around 38-40% of total electricity. These began operation in the 1970s and 1980s and are in need of modernisation to extend their service lives beyond 40 years.

The agreement also set a target of 100% renewable energy by 2040, and called for investments in solar, wind, hydro and bioenergy. The Swedish parliament agreed to phase out over two years a tax on nuclear power, acknowledging nuclear’s role in helping it to eventually achieve that goal. Energy Minister Ibrahim Baylan admitted nuclear power was not a renewable energy. "This is of course a compromise," he said.

A variable production tax on nuclear power introduced in 1984 had been replaced by a tax on installed capacity in 2000. This tax has steadily increased to about 7 öre (0.8 US cents) per kilowatt-hour and in February utility Vattenfall said the tax had brought its nuclear operating costs to around 32 öre per kWh while revenue from nuclear generation was only about 22 öre per kWh.

Swedish utilities had sought to oppose the tax through the courts, but the European Court of Justice ruled last October that Sweden could continue to tax nuclear power, arguing that the tax is a national, rather than European Commission, matter. Vattenfall CEO Magnus Hall welcomed the new agreement, which he said gave the utility the predictability it needed. He said abolition of the nuclear capacity tax was "an important precondition for us to be able to consider the investments needed to secure the long-term operation of our nuclear reactors". Vattenfall’s reactors at Forsmark and Ringhals have undergone a comprehensive modernisation programme to allow them to operate until the mid-2040s. However, in October 2014, the Swedish Radiation Safety Authority said by 2020 all operating Swedish reactors must have a "robust permanent installation that includes power supply and systems for pumping of water and an external water source independent of those used in existing emergency cooling systems". The utilities had said this was economically impossible with the tax in place.

On 16 June, in the wake of the new agreement, Vattenfall said it had decided to invest in the necessary safety upgrades to extend the service life of three boiling water reactors at Forsmark NPP, in which it holds a 66% stake. However, the final decision to proceed with the upgrade will have to be made by the board of Forsmark Kraftgrupp, which operates the plant on behalf of Vattenfall and minority owners E.ON and Mellansvensk Kraftgrupp, with stakes of 8.5% and 25.5%, respectively. Vattenfall noted the project to install independent core cooling in all three reactors at Forsmark "will take several years and will be planned not to impact energy production". The company said a decision on whether to install independent core cooling at units 3 and 4 of the Ringhals NPP, in which it owns a 70.4% stake, will be taken in early 2017.

A study published on 16 June by scientists from the Max Planck Institute and the Royal Institute of Technology said replacing nuclear power with wind in Sweden would double carbon dioxide (CO2) emissions. It found that replacing nuclear with wind power would make the electrical grid unreliable. Conventional natural gas and coal power plants would be needed to compensate for the unreliability, which would create more CO2 emissions. The study was published in the peer-reviewed European Physical Journal Plus.