Nuclear Power in Sweden

Updated Monday, 25 March 2024
  • Sweden's nuclear power reactors provide about 40% of its electricity.
  • In 1980, the government decided to phase out nuclear power. In June 2010, Parliament voted to repeal this policy.
  • The country's 1997 energy policy allowed 10 reactors to operate longer than envisaged by the 1980 phase-out policy, but also resulted in the premature closure of a two-unit plant (1200 MWe). Some 1600 MWe was subsequently added in uprates to the remaining ten reactors.
  • In 2015 decisions were made to close four older reactors by 2020, removing 2.8 GWe net.
  • In June 2023 Sweden replaced its energy target of '100% renewable' electricity by 2040 with '100% fossil-free' electricity allowing the government to push forward with plans for new nuclear plants.
  • In November 2023 the government announced plans to construct two large-scale reactors by 2035 and the equivalent of 10 new reactors, including small modular reactors, by 2045.
6,944 MWe
Reactors Under
0 MWe
4,061 MWe

Operable nuclear power capacity


Electricity sector

Total generation (in 2022): 173 TWh

Generation mix:  hydro 70.3 TWh (41%); nuclear 51.9 TWh (30%); wind 33.1 TWh (19%); biofuels & waste 14.6 TWh (8%); solar 2.0 TWh; coal 0.6 TWh; oil 0.5 TWh; natural gas 0.2 TWh.

Import/export balance: 34.2 TWh net export (6.2 TWh imports; 39.4 TWh exports)

Total consumption: 124 TWh

Per capita consumption: c. 11,900 kWh in 2022

Source: International Energy Agency and The World Bank. Data for year 2022.

Sweden's individual electricity consumption is very high at approximately 12,000 kWh/yr per capita on average. Hydroelectric output depends on seasonal precipitation, varying from 79 TWh in 2000 to 62 TWh in 2018. Total capacity was 43.7 GWe at the end of 20211. By law, the grid operator Svenska Kraftnät must ensure there is 750 MWe winter reserve capacity.

Nuclear power industry

Reactors operating in Sweden


Location of Sweden's operational nuclear power plants

The Nordic and Baltic transmission systems are highly interconnected, and since 2013, Sweden has been a net exporter of electricity.

The reactors in Sweden are owned and operated by Vattenfall (government-owned), and private utilities include Uniper SE (formerly E.ON Sweden, majority-owned by the German government) and Fortum Sweden (majority-owned by the Finnish government). 

Up to the late 1960s, there was a focus on hydroelectricity to power Sweden's industrial growth. In 1965, it was decided to supplement this with nuclear power, to avoid the uncertainties of oil prices and increase the security of supply. The policy was reinforced by the oil shocks of the early 1970s, at a time when Sweden depended on oil for about 75% of its energy consumption and one-fifth of its electricity – at the same time as electricity demand was increasing by 7% per year.  

In the mid-1970s, the nuclear push became a political issue, and 1977 legislation was passed to ensure proper waste management. This provided the basis for Sweden's world leadership in management of used fuel (particularly for those countries not reprocessing it). Following the Three Mile Island accident, a referendum took place in 1980 to decide the future of nuclear energy in Sweden. The outcome of the referendum was to allow the construction of the planned reactors, and for nuclear energy to be phased out by 2010. In 2010, however, the Swedish parliament passed legislation allowing existing reactors to be replaced with new ones on existing sites. 

Following announcements that four reactors would close by 2020 due to declining profitability, representatives of E.On, Vattenfall and Fortum met with the energy minister in November 2015 and warned that the operating environment for energy production in Sweden was "troubling" and in the medium-term nuclear generation should not be taken for granted. Fortum said that while "nuclear safety is always our first priority, ...heavy safety investments together with Sweden's unique capacity tax pose a negative, totally unreasonable burden on nuclear power." (See sections below on the capacity tax and individual plants.)

In mid-2016, as a corollary to repeal of the capacity tax, the government said it envisioned (but did not require) all the present operating nuclear reactors to be shut down by 2050. This would require significant dependence on imported power such as from Finland’s nuclear plants, and would deprive Norway of back-up for its hydro in dry years.

Nuclear industry development

In 1947, the government established an atomic energy research organization, AB Atomenergi. The country's first experimental reactor, R1, was commissioned in 1954. Then, in 1956, a commission recommended development of a nuclear power program also producing heat. Atomenergi commissioned two test reactors – one 50 MWth (R2) reactor and one 1 MWth (R2-0) reactor – located near Nyköping in 1960 to further this goal. (They were operated by Studsvik AB and shut down in mid-2005.)

In 1964 Atomenergi and Vattenfall together commissioned the small (65 MWt and 10MWe) R3 Ågesta heavy water reactor to deliver heat and electricity to the Stockholm suburbs. It operated until 1974. The two organizations then started to build the larger (140 MWe) R4 Marviken heavy water reactor, supplied by ASEA, and the reactor was mostly completed by 1986. However, the project was mired with technical and design problems stemming from the dual requirements for the reactor to produce both electricity and plutonium for the Swedish nuclear weapons programme. The reactor was never loaded with fuel, and was decommissioned in 1970.  

Following a proposal for a small boiling water reactor (BWR), a Sydkraft-led consortium (OKG) ordered a 450 MWe BWR unit – Oskarshamn 1 – from ASEA in 1966. This was the first Western light water reactor designed and built without requiring a licence from US vendors. It started up in 1972.

In 1968, Vattenfall ordered Ringhals 1, a 750 MWe BWR from ASEA, and Ringhals 2, an 800 MWe PWR from Westinghouse, in order to compare the technologies. Two further Westinghouse PWRs were subsequently built at Ringhals, becoming operational in 1981 and 1983. 

In 1969, OKG ordered Oskarshamn 2 and Sydkraft ordered Barsebäck 1 with an option for unit 2, all from ASEA Atom. In the 1970s Vattenfall cooperated with other utilities to build the Forsmark nuclear plant.

Six reactors entered commercial service in the 1970s and six in the 1980s. The 12 reactors were at four sites around the southern and eastern coast. Barsebäck unit 1 closed in 1999 and unit 2 in May 2005. In 2015 it was decided for economic reasons (see Nuclear capacity tax, below) not to complete the extensive and nearly-finished upgrades to Oskarshamn 2 and to permanently shut it down. Oskarshamn 2 closed in December 2016, followed by unit 1 in June 2017. Ringhals 2 closed in December 2019, followed by unit 1 in December 2020.

New nuclear capacity

In October 2022 the agreement on policies of the incoming coalition government (Christian Democrats, Liberals, Moderates, and Sweden Democrats) – referred to as the Tidö Agreement – called for support for investment in nuclear, mainly through SEK 400 billion (about $36 billion) of credit guarantees, and for an investigation into the restart of Ringhals 1&2. The agreement also included changing the energy policy goal from 100% renewables to 100% fossil-free, which was approved by parliament in June 2023.

In November 2023 the government presented a roadmap for new nuclear, announcing its plans to construct two large-scale reactors by 2035 and the equivalent of 10 new reactors, including small modular reactors, by 2045. A few days later, parliament approved legislation to scrap the rules that cap the total number of reactors to ten and confine reactor construction exclusively to locations where they currently exist.

Planned nuclear power reactors in Sweden

Reactor Type Gross MWe Construction start First power
? ? 2x1250 ? By 2035
Total (2) 2500 MWe

Nuclear capacity tax

In connection with the debate regarding the closure of Barsebäck (see Appendix 1: Barsebäck Closure) in the late 1990s the government imposed a capacity tax on nuclear power, at SEK 5514 per MWt per month, which worked out at about 2.8 to 3.0 öre/kWh (0.30-0.32 Euro cents/kWh) potentially produced, penalising nuclear relative to other sources. In January 2006, the tax was almost doubled to SEK 10,200 per MWt per month (about 0.6 Euro cents/kWh then). Early in 2008, it was further increased by 24% to SEK 12,684 per MWt (about 60 SEK/MWh) – reaching a total of SEK 4 billion (€435 million, about 0.64 cents/kWh). This was equal to double the staff cost and made up about one-quarter of the operating cost of nuclear power in Sweden, though in November 2015 Fortum put the proportion at 60% of operating cost.

Earlier in 2014 the new government proposed to raise the tax to SEK 14,770 per MWt per month, or about SEK 70/MWh (€7.50/MWh), and this featured in the April 2015 budget, with parliamentary approval in June. The nuclear industry was then paying about SEK 4.5 billion in tax annually and called for its abolition. After a long process of appeal through the Swedish courts, the European Court of Justice in September 2015 ruled that the tax did comply with EU laws.

Vattenfall said that the tax took its operating costs to 32 öre/kWh (€3.4 cents/kWh) and in April 2016, Magnus Hall, the CEO of Vattenfall, said: "The abolishment of the nuclear tax is needed in order to secure continued operation of our nuclear power plants... Combined with falling electricity prices, the current nuclear tax is contributing to a critical situation in which none of our reactors are profitable." 

After months of negotiation, in June 2016 a framework agreement was announced by the Social Democrats, the Moderate Party, the Green Party, the Centre Party and the Christian Democrats, which saw the tax phased out over two years from 2017. It also allows for the construction of up to ten new nuclear reactors at existing sites, to replace plants as they retire. The Liberal Party and the Left Party withdrew from negotiations and were not party to the agreement.

Vattenfall said that with the abolition of the tax would reduce its generating costs to SEK 190/MWh (€20/MWh) by 2021, from over SEK 300/MWh in 2014-15. 

Boosting nuclear capacity and operational lifetime

The government worked with the utilities to expand nuclear capacity to replace the 1200 MWe lost in closure of Barsebäck 1&2. By the end of 2008, some 1050 MWe had been added to the ten surviving reactors, and by mid-2014, 569 MWe more had been added.

Beyond that, the Swedish grid operator Svenska Kraftnät, in a long-term development plan published in October 2012, noted that the construction of new nuclear generating capacity at Forsmark or Oskarshamn would present problems. It concluded that the Ringhals site would be the most convenient location of any new nuclear power in Sweden. In July 2012, Vattenfall had submitted an application to the Swedish Radiation Safety Authority (SSM) concerning the replacement of up to two of the existing Ringhals reactors with new ones, but without any firm plans to do so.

Vattenfall in May 2013 announced plans to invest SEK16 billion (€1.87 billion) between 2013 and 2017 in modernizing and upgrading the Forsmark and Ringhals plants, as majority owner of both. With the two operating companies, it assessed the additional investments needed to operate the three Forsmark units and Ringhals 3&4 for up to 60 years.

In January 2014 Vattenfall launched a decade-long public consultation on building new nuclear plants, centred on the Ringhals site.

In October 2014 the Swedish Radiation Safety Authority (SSM) announced that 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." This required substantial engineering. The changes were approved by the SSM in December 2020. 


Ringhals applied to the Swedish Nuclear Power Inspectorate (SKI) for a major uprate on the 915 MWe unit 3, on the basis of steam generator replacement already undertaken, and more to follow as low pressure turbines were replaced in 2007. Early in 2008, it was operating at 985 MWe net. In August 2008, work was completed to allow it to operate at 1050 MWe pending approval by SKI's successor, SSM. In May 2009, SSM approved test operation at 1045 MWe, and this increased to 1062 MWe by 2012.

On the older Ringhals BWR unit 1, a 15 MWe uprate was completed in 2007, with another 15 MWe following in 2012. Unit 2 however was downrated by 60 MWe in 2007 to near its original power. The operational lifetime of these two units was curtailed due to low wholesale prices compounding the tax burden on them, and Vattenfall closed them in 2020 and 2019 respectively*. They produced about 12 TWh/yr, about 8% of Sweden’s total. In October 2022 the incoming government called on Vattenfall to investigate whether it would be possible to restart Ringhals 1&2.

Ringhals 4 had a 30 MWe uprate following replacement of its low-pressure turbines in 2007. Exchange of high-pressure turbines and steam generators in 2011 and other work was expected to yield a further 240 MWe, but this did not eventuate at the time. In January 2015 the SSM approved trial operation at 175 MWe higher power level. As of 2022 its capacity was 1130 MWe, 23% higher than when initially corrected the grid. Ringhals 3 has been similarly uprated.

In September 2022 Vattenfall announced that unit 4 would be offline for an extended period due to damage to the pressure vessel during routine maintenance. The unit restarted in early April 2023.

In November 2023 Vattenfall applied to the municipality of Varberg for planning permission to build new nuclear generating capacity on the Värö peninsula to the west of the Ringhals plant. Vattenfall said it aims to deploy new nuclear capacity at the site in the early 2030s.

* In April 2015, government-owned Vattenfall, as the majority owner, announced that, due to declining profitability and increased costs exacerbated by the nuclear tax, it proposed to close Ringhals 1&2 by 2020 instead of 2025 as previously planned, despite recent expenditure on improving safety. In September 2015 Vattenfall said: "Market conditions and the impact of the high output tax have prompted us to limit investments in Ringhals 1&2. The investment decision, which had to wait while talks with E.ON were under way, will not be subject to review." Ongoing investment projects that would have been implemented from 2017 onwards would cease. The final decision to decommission the reactors early was confirmed by the board of directors of the Ringhals plant in October 2015 with E.ON reluctantly consenting to the plans. Ringhals 2 was shut down in December 2019 followed by Ringhals 1 in December 2020.


At Forsmark, uprates of around 8% were carried out at each unit in the 1980s. In 2004, low pressure turbines were replaced in unit 3, giving a 30 MWe uprate, and the same was done for units 1&2.

A major uprate programme was announced in 2004 by Forsmarks Kraftgrupp. This planned SEK 13 billion ($1.8 billion) programme would have added a further 410 MWe to the plant. Following a series of safety concerns, including an incident in July 2006 (see section below on Regulation and safety), the uprate programme was delayed.

Upgrading work then began in the latter half of 2009 on unit 2. This was completed in April 2013, taking capacity to 1118 MWe (1157 gross) at a cost of SEK 1 billion ($118 million). It has been operating at that level since.

The plan was for Forsmark 1 to be uprated by 120 MWe in mid-2011; and unit 3 was to get a new SEK 900 million generator in 2014, which would contribute to a 170 MWe uprate. However, following problems with the work carried out on unit 2, it was decided in November 2010 to indefinitely postpone the upgrading of units 1&3. In mid-2014 the high-pressure turbine of unit 3 was replaced, resulting in 17 MWe more power. In November 2014 the company decided to uprate unit 1 by 114 MWe (from 1022 MWe gross) if grid upgrade could be agreed with Svenska Kraftnät, and to abandon plans to uprate unit 3. In June 2016 Vattenfall's board decided to install independent core cooling systems in the three Forsmark reactors, as required for operation past 2020, with other upgrades. In September 2016 the head of Vattenfall said that the company expected to operate the three Forsmark reactors for a full 60 years.

In June 2022 Vattenfall announced plans to uprate unit 1 by approximately 100 MWe.


In 2005, SKI approved a 250 MWe uprate of the Oskarshamn 3 reactor, to 1450 MWe gross, this was confirmed by the government in January 2006, and in September 2009 SSM approved test operation at the uprated level. The SEK 3.2 billion (€313 million) project involved turbine upgrade by Alstom as well as reactor upgrade, and will extend the plant's life to 60 years. A further three-month upgrade was in mid-2014. In mid-2017 SSM set new conditions for ageing management at the plant, to be implemented in January 2018 and January 2019.

In mid-2009, OKG announced plans to uprate Oskarshamn 2 by 185 MWe and extend its operating lifetime to 60 years. This was approved by SSM in April 2010 and was then expected to be completed in 2015. After the 638 MWe unit was taken out of service in June 2013, this target date for the final phase of work was then deferred, and in June 2015 postponed indefinitely due to reduced demand. Major work including new turbines had been proceeding more slowly than expected and the unit was to be offline until at least the end of 2015. It was to start delivering the higher power – a 28% increase from 661 to 850 MWe gross – about 2017.

However, in June 2015 majority owner E.ON said it would close unit 2 by 2020, since it has been "in great need of modernization and replacement of components to extend its operating life." E.ON added: "It would require large investments to Oskarshamn 2 to meet new requirements for core cooling which take effect after 2020.” In October 2015 it confirmed that the reactor would not be restarted.

Oskarshamn 1 has had three renovations and uprates, in 1995, 1998 and 2002, but in 2012-13 its capacity utilization was low, apparently due to turbine features. In June 2015 OKG applied for permission to permanently shut down the reactor at an unspecified date, but majority owner E.ON said that that should be between 2017 and 2019. In February 2016 OKG decided it would be mid-2017, and it was closed down in June 2017.

E.ON Sweden said: "The conditions for the electricity market have changed significantly in recent years. Historically and permanently low electricity prices, combined with increased output tax on nuclear power, and additional requirements for extensive investments create profitability issues, particularly for small reactors such as Oskarshamn 2.” OKG echoed this in October, saying: "There are no prospects of generating financial profitability either in the short or the long term" at either unit 1 or 2.

Finland’s Fortum, which owns 45.5% of the Oskarshamn units, said that "contrary to E.ON's view, we believe that it is possible to continue production from Oskarshamn units 1 and 2 until the end of their planned operational lifetimes.” Furthermore, "the recent modernization investments in Oskarshamn 2 have been carried out with a target to continue production until the end of the unit's lifetime and with increased capacity. Considering the investments made, as well as our strong expertise as a nuclear operator and a global service provider, we see that there are other measures [that could be] taken to ensure safe and reliable production at Oskarshamn 2 till the end of its planned lifetime.”

Oskarshamn 2 shut down in December 2016, followed by Oskarshamn 1 in June 2017. 

Small modular reactors

Uniper in February 2021 signed a deal with small modular reactor (SMR) developer LeadCold and the Royal Institute of Technology (KTH) aimed at constructing a demonstration SMR at the Oskarshamn site by 2030. The LeadCold SEALER SMR is designed to generate 3-10 MWe over a 10-30 year period without the need to refuel.

In June 2020 Vattenfall announced that it was conducting a pilot study to evaluate the construction of at least two SMRs at a site adjacent to the Ringhals nuclear power plant.

In December 2022 Fortum and Kärnfull announced that they were exploring the development of SMRs in the country, forming part of Fortum's two-year feasibility study announced in October 2022.

Sweden's ambivalent energy policy

The 1979 Three Mile Island accident in the USA resulted in a decision to call a public referendum in Sweden, to remove the issue from the election campaign in October 1979. The 1980 referendum canvassed three options for phasing out nuclear energy, but none for maintaining it. A clear majority of voters favoured running the existing plants and those under construction as long as they contributed economically, in effect to the end of their normal operating lives (assumed then to be 25 years). Parliament decided to embargo further expansion of nuclear power and aim for closing the 12 plants by 2010 if new energy sources were available realistically to replace them. 

The 1986 Chernobyl disaster (first recognized outside the Soviet Union at Forsmark nuclear power station) created some pressure to progress the issue of nuclear decommissioning. In 1988, the government decided to begin the phase-out in 1995, but this decision was overturned in 1991 following pressure from the trade unions.

In 1994, the government appointed an energy commission consisting principally of backbench politicians, which reported at the end of 1995 that a complete phase-out of nuclear power by 2010 would be economically and environmentally impossible. However, it said that one unit might be shut down by 1998.

This gave rise to intense political manoeuvring among the main political parties, all of them minority, with varied attitudes to industrial, nuclear and environmental issues. The Social Democrats ruled a minority government but with any one of the other parties they were able to get a majority in parliament.

Early in 1997, an agreement was forged between the Social Democrats, the Left Party and the Centre Party which resulted in a decision to close the two Barsebäck units, both 600 MWe boiling water reactors constructed by ASEA-Atom and commissioned in 1975 and 1977. They were only 20 kilometres from the Danish capital, Copenhagen, and became a source of contrived concern to the Danes on that account. They were closed in 1999 and 2005 respectively.*

* In 1997, the Swedish government decided to close unit 1 in mid-1998 and unit 2 in mid-2001. Sydkraft, the utility owning Barsebäck, responded by challenging the legality of the decision and made a formal complaint to the European Commission on the basis of unreasonable discrimination. It also negotiated with the Swedish government regarding full compensation in actual generating capacity, not simply money. The result was that the closure of unit 1 was postponed until the end of November 1999 under a complex agreement among the government, Sydkraft and Vattenfall to transfer an interest in the latter's Ringhals plant (one 835 MWe BWR and three slightly larger PWRs) to Sydkraft. Barsebäck 2 continued in operation under a new joint production company, Ringhals AB, in which Sydkraft (subsequently E.ON Sverige) had a 25.8% share (though Barseback 2 contributed only 14.5% of the capacity). Reactor ownership was unchanged. Then in October 2004, after two years of discussion with utilities on the future of the country's nuclear power plants, the Swedish government broke off negotiations and declared that Barsebäck 2 would close in May 2005 after 28 years' operation, regardless of previously-agreed conditions regarding indigenous replacement power. E.ON took full ownership of E.ON Sverige when it acquired Statkraft's 44.6% stake in the company in mid-2008.

The positive aspect of this decision to close Barsebäck was that the other ten reactors gained a reprieve beyond 2010, allowing them to run for about 40 years (i.e. closing 2012-2025) and possibly 60 years, to 2045. 

In the 1970s, it was the Centre Party in Sweden that started the anti-nuclear debate culminating in the 1980 referendum canvassing three options for phasing out nuclear energy. Since then the Centre Party lined up with the three socialist parties on nuclear power, but the three non-socialist parties on other issues. Then, early in 2005 and against a background of increasing electricity prices, the leadership of the Centre Party indicated a substantial reversal of this earlier anti-nuclear position, saying that climate change must be put ahead of nuclear decommissioning. The party abandoned its alignment with the socialist parties on energy policy and fully joined the three pro-nuclear parties, so as to allow nuclear power to continue supplying a major part of the country's electricity. This view was in line with the overwhelming majority of public opinion.

Following the 2006 elections, the Moderate Party, the Centre Party, the Christian Democrats, and the Liberal People's Party – the centre-right Alliance for Sweden (Allians för Sverige) – formed a coalition government. While no reactors would be closed, planning of new units was not originally on the agenda during the coalition's first term. However, several major reactor upgrades were to be undertaken. In March 2007, the Christian Democrats changed their policy to explicitly disown the phase-out and allow for new reactors being built after 2010. Early in 2008, leaders of the Liberal People's Party called for construction of four new reactors at existing sites as replacements for those which would be retired in the 2020s. 

Then, in February 2009, the centre-right coalition government said it planned to abolish the act banning construction of new nuclear reactors2. This was narrowly approved by Parliament in June 2010, though construction will only be at existing sites and to replace the units then present. This is part of the government's climate program, which stipulated that by 2020, renewable sources should supply half of all energy produced, the Swedish car fleet should be independent of fossil fuels in 10 years, and the country should be carbon-neutral by 2050. In mid-2012 Vattenfall applied to SSM to build two new reactors at Ringhals or Forsmark, though it made clear that a decision on construction was up to ten years off, with the power being required after 2025. "Current regulations are such that it is only through applying for a permit for replacement reactors that Vattenfall will obtain some of the answers needed to complete a decision basis," it said.

Following elections in mid-2014, the junior coalition Green Party in the new government persuaded its Social Democrat partner to set up an energy commission to review the future of energy in Sweden. Social Democrat leader Stefan Löfven had earlier said that nuclear power would be needed for "the foreseeable future", though the Greens campaigned to have two of Sweden's reactors closed in the next four years. The Social Democrats got 31% of the vote in the election, and the Greens 7%. Public opinion polls in the last few years had shown steady majority (over two-thirds) support for nuclear power.

The two parties said in separate but identical statements that nuclear power should be replaced with renewable energy and energy efficiency. The goal, they said, should be at least 30 TWh/yr of electricity from non-hydro renewable energy sources by 2020, compared with about 18 TWh/yr then. The two parties said that nuclear power "should bear a greater share of its economic cost", despite (at the time) Sweden’s unique high tax specifically on nuclear power (about 0.67 Euro cents/kWh) already, and waste management being fully factored into running costs at 0.436 cents/kWh. 

In June 2023 Sweden's parliament voted to change the country's target from '100% renewable' electricity production by 2040 to '100% fossil-free' electricity. The country's finance minister said: "This creates the conditions for nuclear power. We need more electricity production, we need clean electricity and we need a stable energy system."

Fuel cycle

Sweden imports most of its nuclear fuel, including all enrichment. In the case of Forsmark, these have been provided: 20% Eurodif (diffusion), 60% Urenco, 20% Tenex (both centrifuge).

Westinghouse has a fuel fabrication plant at Västerås, which produces about 400 tonnes of BWR and PWR fuel per year, supplying numerous European countries. Vattenfall sources fabricated fuel from Westinghouse, Areva in France and TVEL in Russia.

Sweden has some uranium mineralization but no mines. The IAEA-OECD ‘Red Book’ 2022 estimates resources of over one million tU in Sweden’s alum black shales (schists) in three deposits. Some 200 tU was produced from a black shale deposit in Ranstad in the 1960s. 

Australia's Aura Energy in August 2011 announced JORC-compliant inferred resources of 286,000 tU3O8 at an average grade of 0.016% in the alum black shales at Häggån about 40 km southwest of Östersund in central Sweden. In 2018, the Swedish government banned uranium exploration and mining in Sweden, cancelling any potential uranium production from the proposed mine, with Aura Energy seeking compensation from the government for the financial loss incurred. 

Waste management

The Swedish Nuclear Fuel and Waste Management Company (Svensk Kärnbränslehantering AB, SKB) was set up by the nuclear utilities following the Waste Legislation (Stipulation Act) in 1977 to develop a comprehensive concept for the management and disposal of used fuel and other radioactive wastes. It is owned 36% by Vattenfall, 30% Forsmark, 22% OKG and 12% E.ON Sweden. It reports on its R&D program every three years, and the government must approve this.

Nuclear generators are responsible for the costs of managing and disposing of spent fuel, and must provide for those costs as they go. They pay a fee set by the government to a state fund administered by SSM to cover waste management and decommissioning. This is based on advice from SKB and has averaged SEK 0.02/kWh (0.21 Euro cents/kWh). In 2011 SSM recommended an increase in the fee due to estimating that SKB's deep SFR repository would cost more than anticipated. In 2010 SKB estimated that the total cost for wastes and decommissioning would be SEK 123 billion, and said that the fund had SEK 43 billion in it then. In December 2011 the government announced that the fee would be SEK 0.022/kWh (¢0.32 US; 0.24 € cents) for 2012-14, compared with the SSM recommendation then of SEK 0.03.

However, in June 2013 SSM said that the charges should be based on 50-year reactor lifetimes, not 40-year ones as at present, so the fee could be maintained. In October 2014 SSM recommended that the fee be increased to SEK 0.04/kWh (0.44 € cents), since it thought SKB had underestimated the cost of decommissioning and building the repository by at least SEK 11 billion. The government confirmed the new fee level for 2015-17 in December 2014. In 2017, SSM recommended a further rise to 5.0 öre per kWh (0.48 € cents) for the period 2018-2020. SKB estimates the decommissioning and repository costs at about SEK 78 billion.

Some low-level waste is disposed of at reactor sites, and some is incinerated at the Studsvik RadWaste incineration facility in Nyköping.

SKB's dedicated ship, M/S Sigrid, moves the used fuel and wastes from power plants to storage or repositories. In 2014 it replaced the smaller Sigyn.

A final underground repository (SFR) for operational (up to intermediate-level) radioactive waste and medical and industrial radioactive wastes has been operating near Forsmark since 1988. It has 63,000 cubic metre capacity and receives about 1000 cubic metres per year. This was also one of the locations proposed by the local Östhammar community for a final high-level waste (HLW) repository. It is some 50 metres below the Baltic Sea.

In November 2022 a new interim storage facility for low- and intermediate-level radioactive waste began operation. The facility, based in Studsvik, was to initially be used for the storage of waste from the Ågesta nuclear power plant and the R2 research reactor.

In October 2022 SKB revaluated the remaining costs for the country's radioactive waste programme, which totalled SEK124.1 billion ($11 billion), a $1 billion increase from 2019 estimates.

In April 2023 SKB submitted an application to SSM to expand the SFR final repository for low- and intermediate-level waste at Forsmark to almost three times its size, including six new rock vaults all 240-275 metres long. The expansion is expected to take six years to complete.

High-level waste

The CLAB interim repository for used fuel (treated as high-level waste) has been operating since 1985 at Oskarshamn, and its original 5000 tonne capacitya was expanded to 8000 tonnes soon after 2000, and in 2015 SKB applied to extend it to 11,000 tonnes to cater for all the fuel from all the present reactors. The used fuel is stored under water in an underground rock cavern for some 40-50 years. It will then be encapsulated in copper canisters with a cast iron internal structure for final emplacement packed with bentonite clay in a 500 metre deep repository in granite. In mid-2020 about 7300 tonnes of used fuel was at CLAB. In August 2021 the government approved expansion to 11,000 tonnes.

Research at the Äspö Hard Rock Laboratory nearby identified geological characteristics for this final deep repository. Site selection procedures from 2002 resulted in two municipalities voting to be candidate locations for a deep geological repository – Oskarshamn (Simpevarp and Laxemar) and Östhammar (Forsmark). Both these had been selected as having potentially suitable bedrock characteristics, after feasibility studies in eight municipalities. An April 2008 independent poll in both communities (N=900 in each) showed that 83% of Oskarshamn residents and 77% of those in Östhammar supported having the future repository in their own locality. Six neighbouring localities were also surveyed in 2008 and, while the majority of residents were in favour of a final repository in the neighbouring municipalities, support diminished as distance from ongoing nuclear power operations increased.

SKB announced its decision to locate the repository at Soderviken near Forsmark in Östhammar municipality, on the basis of it having the best geology, in June 2009. In April it had signed an investment agreement with both volunteer municipalities specifying investment of SKR 2 billion ($245 million) in the two, with the majority going to the unsuccessful bidder, which will thereby be disadvantaged financially. SKB applied for a licence to construct the repository in March 2011, and planned to begin site works in 2013. In June and November 2015 SSM responded with preliminary findings that the plan should meet all its safety and radiation protection requirements, both in operation and following closure.

SKB applied for a permit to build the Clink encapsulation plant next to CLAB at Oskarshamn in November 2006. This will be operated with CLAB, as an integrated facility. Encapsulated used fuel will make its last journey from here to the repository at Östhammar. In June 2012 an OECD Nuclear Energy Agency review reported to the government that SKB’s whole repository concept was sound and met long-term safety requirements. In March 2016 SSM expressed a positive opinion of SKB plans for the integrated CLAB-encapsulation facility.

In June 2016 SSM assessed that SKB's licence application including encapsulation plant and Forsmark repository had the potential to comply with its requirements, and recommended to the Land and Environment Court in Stockholm that it should be allowed. In January 2018 SSM submitted a positive opinion to the government on SKB's application. However, the Land and Environmental Court called for further documentation on the copper canisters in which the fuel will be stored. SKB hopes to commence the ten-year construction in the mid-2020s.

The repository will have 12,000 tonnes capacity at 500 metres depth in 1.9 billion year-old granite. A 5 km ramp will connect to an eventual 60 km of tunnels over 4 sq km, housing 6000 copper-cast iron canisters containing the used fuel. Each 25-tonne canister will hold 2 tonnes of used fuel. Bentonite clay would surround each canister to adsorb any leakage. The repository concept is known as KBS-3. KBS-3H has canisters horizontally, KBS-3V has them vertically.

In May 2021 Ringhals AB and Forsmarks Kraftgrupp AB issued an 'urgent market message' to Nord Pool power exchange about the potential risk of Ringhals 3&4 and Forsmark 1-3 being unable to restart following scheduled outages due to lack of onsite storage space for used nuclear fuel. The message stated that the situation was an indirect result of the Swedish government’s slow handling of an application to extend the capacity of the intermediate storage facility, CLAB.

In August 2021 the Swedish government approved an application by SKB to allow the placement of additional spent fuel in CLAB, but separated that approval from a decision on whether to grant a construction licence for the planned permanent repository near Forsmark. Vattenfall filed an urgent market message with Nord Pool in response, warning that it might have to shut its Forsmark and Ringhals plants in 2024/2025 as a result. In the event, a construction licence for the final repository was approved by the government in January 2022. The decision makes Sweden only the second country (after Finland) to grant a construction licence for a commercial spent fuel repository.

Some 4.8 tonnes of metal used fuel from the R-1 research reactor has been sent to the UK's Sellafield for reprocessing in the Magnox reprocessing plant, since it cannot safely be stored long-term. Plutonium from this will be combined with the small quantity (825 kg) from reprocessed Oskarshamn fuel (reprocessed in 1997 under a 1969 agreement) and either returned as MOX fuel or used in the UK as MOX fuel. The reprocessed Oskarshamn uranium was recycled as fuel for that plant.


Eight power reactors – Ågesta, Marviken (never operated), Barsebäck 1&2, Oskarshamn 1&2 and Ringhals 1&2  – are permanently shutdown and at various stages of decommissioning, along with three research reactors – R1, R2 and R2-0 at Studsvik's Nyköping site. R1 has now been dismantled.

Swedish reactors being decommissioned

Reactor Type Net capacity MWe Commercial operation
Ågesta Prot HWR 10 1964 - 1974
Barsebäck 1 BWR 600 1975 - 1999
Barsebäck 2 BWR 600 1977 - 2005
Oskarshamn 2 BWR 638 1974 - 2013
Oskarshamn 1 BWR 473 1972 - 2017
Ringhals 2 PWR 852 1974 - 2019
Ringhals 1 BWR 881 1976 - 2020

See also information page on Waste Management in the Nuclear Fuel Cycle Appendix 3: National Policies.

Research and development

Studsvik is a public company whose origins were in 1947 as a largely state-owned enterprise. In the 1960s, it relocated from Stockholm to Studsvik near Nyköping, focused on pure R&D and subsequently it became industry-funded and owned. In the 1990s, it became an international enterprise.

Studsvik's 600 kWth R1 research reactor operated 1954-70. R2-0 was a 1 MWt research reactor which operated from 1960-2005. R2 was a large (50 MWt) test reactor which operated 1960-2005. Both R2 and R2-0 were used for isotope production.

The R2 test reactor was involved with international research programmes testing reactor fuel elements. It used high-enriched fuel supplied by the USA and with used fuel returned to the USA. In collaboration with CERCA in France the company was working on qualifying a high-density U-Mo fuel to enable low enrichment to be used. However, R2 was shut down in mid-2005 and its work taken over by the 20 MWt Halden heavy water reactor in Norway, operated by IFE.

Ågesta (10 MWe plus 65 MWt district heating) was built as a prototype heavy water power reactor which if necessary could serve as a stopgap source of plutonium for Sweden's nuclear arsenal (which had been proposed in the 1950s). It was also known as R3 and operated 1964-74. The Marviken (R4) heavy water reactor outside Norrköping was intended for research plus power generation (140 MWe) and plutonium production for Sweden’s nascent nuclear weapons programme, but was never fuelled or operated, and work was abandoned in 1970 after six years' construction. 

A ban on nuclear research was removed in 2006.

In March 2023 LeadCold announced plans for a feasibility study to investigate the conditions for building and operating a research reactor in Studsvik.

Public opinion

Public opinion in Sweden has been much tested. The first point to note is that the 1980 referendum did not canvass any option for continuing Sweden's nuclear power programme, only for different ways of shutting it down.

Since then, however, public opinion has strengthened in favour of nuclear energy.

In April 2004, 77% of people gave top environmental priority to restraining greenhouse gas emissions, 13% to protecting unspoiled rivers from hydroelectric development, and only 7% to phasing out nuclear power. On nuclear power matters, 17% supported a nuclear phase-out, 27% favoured continued operation of all the country's nuclear power units, 32% favoured this plus their replacement in due course, and 21% wanted to further develop nuclear power in Sweden. The total support for maintaining or increasing nuclear power thus was 80% as the government tried to negotiate a phase-out. This total support had risen to 83% in March 2005, with a similar proportion saying that limiting greenhouse gas emissions should be the top environmental priority.

In May 2011, immediately after the Fukushima accident, a Novus poll (N=1000) commissioned by the KSU showed 33% support for continuing to use nuclear power and replace existing reactors, 36% for continuing to use existing reactors and 24% wanting to phase out by political edict. In August 2010 there had been 40% support for use and replace and only 19% for phase-out.

In October 2019 a Novus poll showed 43% support for continuing to use nuclear power and replace existing reactors, 35% for continuing to use existing reactors, and just 11% wanting to phase out.

In October-November 2020 a Novus poll showed 39% in favour of building new nuclear power plants, 31% in favour of continuing to run existing ones, and 16% wanting to phase out nuclear power, with 14% undecided.

In June 2021, a Novus poll showed 46% in favour of building new nuclear power plants, 31% in favour of continuing to run existing ones, and 14% wanting to phase out nuclear power. 10% of respondents were undecided.

In December 2022 Analysgruppen released an opinion poll highlighting: 59% support for the use of nuclear power and, if need be, the construction of new reactors; 26% in favour of using existing reactors, but not build any new ones; and 8% preferring the premature phase-out of nuclear power.

Regulation, safety and non-proliferation

An Atomic Energy Act was passed in 1956, followed by a Radiation Protection Act in 1958. The Atomic Energy Act and several others were superseded by the Nuclear Activities Act in 1984.

In the 1960s the Swedish Nuclear Power Inspectorate (SKI) was set up and became responsible for licensing, regulation and supervision under the Nuclear Activities Act. Its three divisions were reactor safety, safeguards, and research. The Swedish Radiation Protection Institute (SSI) operated under the Radiation Protection Act 1988. In mid-2008, the two organizations were merged to become the independent Swedish Radiation Safety Authority (SSM) encompassing both radiation protection and nuclear safety regulation.

In July 2006, a safety-related incident at Forsmark received a lot of media coverage. It was eventually assigned a rating of Level 2 on the International Nuclear Event Scale (INES). Following a request by management of the three nuclear plants, in March 2007 the director of the International Atomic Energy Agency's Operational Safety Section met with representatives from SKI and the Swedish Radiation Protection Authority as well as management from the three plants and the Environment Ministry. This was to discuss safety culture problems and to arrange Operational Safety Team Review (OSART) missions to the Swedish reactors, the first being to Forsmark.b

The nuclear training and safety centre (Kärnkraftsäkerhet och Utbildning AB, KSU) is a vital ancillary organization and is responsible for training staff and for liaison with the World Association of Nuclear Operators (WANO). It is part of Vattenfall but owned by all the power plants. The Analysis Group, focused on nuclear safety and with a public information role, is administered by KSU.


Sweden is a party to the Nuclear Non-Proliferation Treaty (NPT) as a non-nuclear weapons state. The country signed the Treaty in 1968, when it cancelled the country's research into nuclear weapons that had begun after the end of the Second World War. Its safeguards agreement under the NPT came into force in 1975 and in 1995 it came under the Euratom safeguards arrangement. In 1998, it signed the Additional Protocol in relation to its safeguards agreements with both IAEA and Euratom.

Notes & references


a. The original 5000 t capacity at CLAB allowed for 20,000 BWR fuel assemblies and 2500 PWR assemblies. [Back]

b. Information on the Forsmark incident was available on the Vattenfall website, including: Forsmark nuclear power plant shut down after incident news release (8 August 2006); IAEA Concludes Operational Safety Review of Sweden’s Forsmark Nuclear Power Plant news release (28 February 2008). See also: Report of the Operational Safety Review Team (OSART) Mission to the Forsmark Nuclear Power Plant Sweden 12-28 February 2008, Division of Nuclear Installation Safety, International Atomic Energy Agency, Operational Safety Review Mission IAEA-NSNI/OSART/08/145. [Back]


1. Capacity figures: Energiföretagen Sverige - Swedenergy [Back]
2. Sweden reverses its nuclear phase out, World Nuclear News (5 February 2009) [Back]


Nuclear Power in Sweden Appendix 1: Barsebäck Closure

Radioactive Waste Management Appendix 2: National Policies and Funding