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Nuclear Power in Switzerland

(Updated November 2014)

  • Switzerland has 5 nuclear reactors generating 40% of its electricity. Two large new units were planned.
  • A national vote had confirmed nuclear energy as part of Switzerland's electricity mix.
  • In June 2011 parliament resolved not to replace any reactors, and hence to phase out nuclear power by 2034, despite continuing strong public support for nuclear power.

Electricity consumption in Switzerland has been growing at about 2% per year since 1980. In 2013 electricity production was 70 TWh gross, practically all from nuclear and hydro. A lot of electricity is imported from France, Austria and Germany and up to 26 TWh/yr exported to Italy, with exports and imports largely balanced. Per capita consumption is about 7400 kWh/yr. In 2013 nuclear power contributed 26.0 TWh, 37% of Swiss total production, with hydro supplying 40.0 TWh (57%).

Government policy and industry development

The country's first research reactor – the 10 MW SAPHIR – started up in 1957, having been bought from the USA, and it ran until 1993. A second unit – DIORIT (30 MW) – was designed and constructed indigenously and started up in 1960, running until 1977. In 1960 the Swiss government took over the research centre operating both reactors and in 1988 this became the Paul Scherrer Institute – a flagship research centre.

Construction of an experimental power reactor was commenced in 1962 at Lucens. This was a 30 MWt, 7 MWe heavy-water moderated gas-cooled unit located in an underground cavern. It started up in 1966 but experienced a core melt in 1969 and was written off.

In the 1960s it was evident that Swiss power demand would exceed the potential for supply from hydro sources, so utilities proposed building coal- and oil-fired plants. However, this was strenuously opposed by environmental groups and others on the basis of compromising the hitherto clean power generation, so the government encouraged the utilities to plan for nuclear power.

The country's first commercial units were Beznau 1 – a Westinghouse pressurised water reactor ordered by NOK (Nordostschweizerische Kraftwerke AG) and soon duplicated, and Mühleberg – a General Electric boiling water reactor ordered by BKW (Bernische Kraftwerke AG), located 15 km from Bern.

Following these three units, a consortium of utilities - Kernkraftwerk Gösgen (KKG), ordered a large PWR from Siemens KWU for Gösgen and the same year another utility consortium (KKL) ordered a similar-sized General Electric BWR for Leibstadt.

A further unit (950 MWe) was proposed for Kaiseraugst near Basel, but this was abandoned following anti-nuclear opposition, as was the Graben proposal (1140 MWe).

Both Beznau and Gösgen produce district heating in addition to power. Beznau makes available 80 MW of heat to industry and homes over a 130 km network serving 11 towns – potentially 2.5 PJ/yr.

All Swiss reactors have had power uprates – the Beznau units from 350 MWe, Mühleberg from 306 MWe (the latest: 17 MWe January 2009, including replacement low pressure turbines), Gösgen from 920 MWe and Leibstadt from 942 MWe. Further work to uprate Liebstadt is under way in 2011.

All Swiss reactors except Muehleberg have unlimited-duration operating licences, as long as they can demonstrate safety to the regulator. Muehleberg must be relicensed every ten years, the latest being in December 2009 on condition that it met nuclear safety requirements. However, in 2012 the Federal Administrative Court ruled that the reactor should close in mid 2013 on safety grounds. It said that the issue of safety was too important to be the sole responsibility of the regulator, the Swiss Federal Nuclear Safety Inspectorate, and that if BKW wanted to operate beyond mid-2013 it would need to make a strong case for that. BKW, along with the Energy Ministry, appealed, and in March 2013 the Supreme Court reversed the ruling. It appears that Gosgen and Liebstadt at least will justify the expenditure required to permit operation to 60 years.

BKW considered its options regarding safety-related upgrades to Muehleberg, and decided in October 2013 to spend some CHF 200 million on safety upgrades and close the reactor in 2019. Prolonging its life to 2022 as planned would involve higher costs in the context of “uncertainty surrounding political and regulatory trends”. In May 2014 citizens of Bern canton effectively approved the 2019 closure date with a 63% vote rejecting an early shutdown proposal. This was the first Swiss public vote on nuclear power since the government 2011 decision to phase it out, and is consistent with a 2013 poll (see below).

Meanwhile the canton government had said that it was prepared to negotiate with BKW and possibly let the reactor run until 2022 since a closure agreed with BKW posed less of a risk to the canton in term of liability, while also complying with the national energy policy, which calls for the orderly exit from nuclear power. The Bern canton is the majority shareholder in BKW, the remaining shares are held by Groupe E (10%), EOn Energie (7%) and BKW FMB Energy Ltd (10%), with the remaining 20% held by other parties.

NOK Axpo, operating Beznau and Leibstadt, is part of the Axpo Group owned by the cantons in the northeastern part of the country. Another utility consortium ATEL (now Alpiq) owned 40% of Gosgen and 27.4% of Leibstadt.

In 2009 ATEL merged with EOS to form Alpiq Holding SA, the country's largest power utility. Early in 2009 EdF increased its stake in Alpiq to 25%. One-third of Alpiq's electricity is nuclear.

Operating Swiss Power Reactors

Reactors Operator Type Net MWe First power Expected closure
(approx)
Beznau 1
NOK Axpo
PWR
365
1969
2019
Beznau 2
NOK Axpo
PWR
365
1971
2021
Gösgen
KKG/Alpiq
PWR
985
1979
2029
Mühleberg
BKW
BWR
372
1971
2019 or 2022
Leibstadt
NOK/Alpiq
BWR
1165
1984
2034
Total (5)
 
 
3252 MWe
 
 

MWe data 9/3/04 from SVA. Muehleberg was uprated in Jan 2009 by about 18 MWe gross, Goesgen in January 2010 by 15 MWe (net & gross)

Energy Policy 1990 onwards

A ten-year moratorium on new plant construction was supported by 54.6% of the electorate during a national referendum in 1990.

Then in a unique 2003 referendum which would have been binding and written into the constitution, Swiss voters firmly rejected two anti-nuclear proposals which were originally put forward in 1998. "Electricity without Nuclear" was overtly to phase out nuclear power by 2014, while "Moratorium Plus" would have led to a similar outcome by, amongst other things, removing incentives to invest in and upgrade nuclear plants. Two thirds of voters rejected the first proposal and 58% rejected the second, with practically all cantons refusing both.

In November 2010 the Federal Nuclear Safety Inspectorate (ENSI) drew up definitive appraisals for the Swiss Federal Office of Energy saying that the Niederamt, Beznau and Müheleberg sites are suitable for the purpose of building new reactors. ENSI's findings on the applications will be open to review as part of a public enquiry in mid-2011. A federal decision on granting general authorisations for the plants was expected by mid-2012, according to ENSI. The Federal Office of Energy was reported to favour construction of two new reactors, not three.

Following a decision by cabinet to ignore a referendum that had supported new nuclear power only one month earlier and declare that the country's nuclear power plants would not be replaced, the Federal Council on 7 June 2011 voted 101 to 54 to endorse this, so that nuclear energy is phased out in due course, perhaps 2034 (on the basis of a 50-year life for the newest unit). The proposal was also approved by the upper house, the 46-member Council of States, by 3:1, though subject to ongoing review of technology options which might allow new plants. A new government took office in December 2011, and it was to produce a new energy policy without nuclear power by 2013 and submit that to parliament. Until this is produced and considered the long-term future of nuclear power remains uncertain. The Federal Council proposes building a number of gas-fired plants – both CHP and CCGT – with subsidies, and raising electricity tariffs.

In November 2014 the lower house (Nationalrat) energy committee called for the introduction of a system requiring operators to submit plans for improving the safety of reactors after 40 years of service. A Green Party initiative to limit the life of nuclear power stations to 45 years was rejected. If approved by the regulator (ENSI), this would enable reactors to continue in operation for a further 10-year period, with no limit to the number of 10-year extensions. If a reactor was judged unfit to continue in operation, the operator would receive no compensation.

Axpo responded critically to this ‘long-term operation concept’ proposal: “To begin with it will almost automatically lead to safety shortcomings, compared to the present legal requirements. Secondly it will allow the government to order the shutdown of a reactor, temporarily at least, without any objective shortcomings at the level of the existing legal safety requirements, for purely political reasons. The reactors could only return to production after procedures that will take years. And thirdly the concept would force the operators of nuclear plant, due to the lack of legal and planning certainty, to renounce for economic reasons any further investment in expensive safety-related retrofits and to plan for the premature decommissioning of the reactor in question.”

An annual poll of 2200 people in October 2013 showed that 64% of citizens considered that the country’s five nuclear reactors were essential in meeting the electricity demand – a 3% increase from the 2012 poll figure, but about average from 2001. Three-quarters thought that Swiss nuclear plants were safe, and 68% said that they should remain in operation. While 62% recognised cost advantages in using nuclear energy, only 42% believed that they reduced CO2 emissions. Some 88% said that the country’s energy policy should not jeopardise security of supply, 78% did not want to become more dependent on other countries, and 73% wanted Switzerland to produce all its own electricity. Finally, 78% said they wanted to vote on the country’s energy transition and nuclear phase-out.

New nuclear capacity planned

In 2006 ATEL was looking for partners to build a further large nuclear power plant using proven technology and probably at an existing nuclear plant site. Also Axpo Holding AG had been studying sites for a new nuclear power plant – possibly Beznau.

The Swiss government announced early in 2007 that the existing five nuclear power reactors should be replaced in due course with new units. The new energy policy included renewables, energy efficiency and gas-fired plants, but had nuclear continuing to carry the main load apart from hydro, which is not amenable to expansion. Without new investment a 20 billion kWh/yr shortfall is predicted by 2020 – 25% of demand then. This is due to phasing out of an electricity import arrangement from France, closure of the small Beznau and Muhleberg reactors and closure of the 355 MWe Mill Mountain hydro plant, effectively removing 2400 MWe.

In 2007 the Resun joint venture was formed by NOK Axpo (57.75%), BKW FMB Energie (31.25%) and Centralschweizerische Kraftwerk (11%) to apply to construct two reactors of up to 1600 MWe each at Beznau and Muhleberg site. ATEL (now Apiq) was invited to join the venture, but did not do so at that stage. Then in December 2008 the Axpo Group and BKW FMB Energie filed framework permit applications for new nuclear units at Beznau and Mühleberg, a first step towards the replacement of the three small nuclear reactors there which are due to close 2019-22. Two identical new 1100 to 1700 MWe reactors are envisaged, with hybrid cooling system to minimize water use. Bids for these are being sought by April 2011.M

Meanwhile, in June 2008 ATEL subsidiary Nuclear Power Plant Niederamt Ltd applied to the Federal Office of Energy for framework approval to build a new nuclear power plant in Niederamt near Gosgen. An advanced 1100 to 1600 MWe reactor was envisaged, with hybrid cooling system which will minimize water use. Estimated cost was EUR 3.7 to 4.5 billion to be shared by partners, with start-up expected after 2020. It was in discussion with possible partners, including Axpo and BKW FMB Energie. There is strong local support for the project, and in October 2007 the canton parliament called for “rapid construction of a nuclear power station in Niederamt”. Alpiq was pursuing this.

In December 2010 Axpo, Alpiq and BKW joined forces to form a joint planning company on an equal basis to pursue construction of two identical new nuclear power reactors of up to about 1600 MWe at two of the Niederamt, Beznau or Müheleberg sites. Axpo and one of its subsidiaries will take 59% of the power from the new reactors, Alpiq will take 25.5%, and BKW will have 15.5% – the ratio being according to the three partners' existing shares of Switzerland's nuclear power capacity.

Fuel cycle

Uranium is procured on world markets, enrichment is provided by a variety of contractors, and fuel fabrication is similarly diverse.

Radioactive Waste Management

Radioactive waste is mostly handled by Zwilag, a company owned by the four Swiss nuclear utilities. Its ZZL (zentrales Zwischenlager) commenced operation as a central interim dry cask storage facility for high-level wastes in 2001 at Würenlingen. This is adjacent to the Paul Scherrer Institute, near NOK's Beznau nuclear power plant, and not far from two others. The Zwilag site also has facilities for incineration (in a high temperature plasma oven), conditioning and storage of low- and intermediate-level radioactive wastes.

There is no national policy regarding reprocessing or direct disposal of used fuel. However, utilities have been sending it for reprocessing it so as to utilise the separated plutonium in Mixed Oxide (MOX) fuel.

Reprocessing is undertaken by Areva, at La Hague in France and by BNFL at Sellafield in UK under contract to individual power plant operators. Most used fuel is transported by rail (and ship to UK). Switzerland remains responsible for the separated high-level wastes which are returned. About 1000 tonnes of used fuel has been so far sent abroad for reprocessing, but the 2005 Nuclear Energy Act halted this for ten years from mid-2006. Used fuel is now retained at the reactors or sent to Zwilag ZZL for interim above-ground storage, being managed as high-level waste.

The Gosgen plant has limited pool capacity for used fuel storage so will operate an on-site independent fuel storage facility which allows cooling before used fuel is sent to Zwilag ZZL.

In 1972 a national co-operative for disposal of radioactive wastes (NAGRA) was set up, involving power plant operators and the federal government.

NAGRA submitted a demonstration of feasibility of disposal report (Entsorgungsnachweis) to the Swiss government in 2002. The report showed that used fuel elements, separated high-level waste and long-lived intermediate-level waste could be safely disposed of in Switzerland. In June 2006, the Federal Council concluded that the legally required demonstration of disposal feasibility for all these had been successfully provided. Meanwhile the 2005 Nuclear Energy Act required the waste management and disposal program to proceed and be reviewed by the federal authorities. Identification of site options for disposal is proceeding under this Act and the Spatial Planning Act with regional participation, and following federal approval the actual site selection in three stages will follow. In 2012 the Swiss Federal Office for Energy undertook a three-month consultation on NAGRA’s 2008 repository plans and six possible regions. The Federal Office will pursue investigation of these in 2014. A third phase of the process with provisional site selection is expected over 2016-2021, and a final decision by the government is expected by 2027.

A proposal for a low- and intermediate-level waste repository at Wellenberg was blocked by a cantonal referendum in 1995. A federal working group reviewed the proposal and recommended in 2000 that it proceed, though modified to allow for retrieval. A further cantonal referendum blocked it in 2002. The revised Nuclear Energy Act removes the cantonal veto right, but requires a national referendum.

Low- and intermediate-level waste from the nuclear power plants is processed into a form suitable for disposal either at sites of origin or at ZZL Würenlingen. It is packaged into suitable containers and then stored in facilities at the power plants or at ZZL. Two smaller interim storage sites for these wastes have been operating since 1993: the government's BZL associated with the Paul Scherrer Institute at Würenlingen, and Zwibez at Beznau, which also has a storage hall for dry cask storage of spent fuel and high-level wastes.

At the end of 2006, the volume of packaged low- and intermediate-level waste was 6830 cubic metres. Added to this are the high-level waste and used fuel stored at the power plants and at Zwilag ZZL. At the end of 2006, there were eight containers with separated high-level waste from reprocessing and 17 containers with used fuel stored at ZZL. (A container is around 6 metres high and 2.5 metres diameter.)

Total costs of radioactive waste management are estimated at CHF 16.0 billion, including a 50-year post-operational monitoring phase. Nuclear plant owners pay into a national waste disposal fund created in 2002. A Decommissioning Fund was established in 1984 and power plant operators also pay annual contributions to this. The projected requirement is CHF 3.0 billion plus CHF 1.7 billion for post-operational preparation. At the end of 2102 the accumulated capital in both funds was CHF 4.8 billion, with CHF 5.1 billion having already been paid for waste management.

A Decommissioning Fund was established in 1984 and power plant operators pay annual contributions to this. At end of 2005 it held over CHF 1.25 billion, with projected requirement being CHF 1.9 billion.

Both programs are funded under the Nuclear Energy Act by a levy of about CHF 1 cent/kWh on nuclear power production. The government has proposed a sharp rise in the contributions to both funds from mid 2014, though a 2011 review of the funding showed that liabilities would be fully covered.

Regulation and safety

The main legislation governing nuclear energy is the 1959 Atomic Energy Act. It was updated in 1978 and 2003 (coming into force in 2005). An attempt to limit the operating lives of reactors and ban reprocessing of spent fuel was defeated.

The Swiss Federal Nuclear Safety Inspectorate (ENSI) is the national regulatory body with responsibility for the nuclear safety and security of Swiss nuclear facilities. It took over from the Swiss Federal Nuclear Safety Inspectorate (HSK) in 2009, but is an independent body rather than being under the Swiss Federal Office of Energy. It monitors and regulates both safety and radiological protection in nuclear installations and waste facilities. HSK was set up under the Federal Energy Office in 1982, and since 2003 there have been legislative moves to make it independent, culminating in a 2007 Act setting up ENSI.

Civil liability for nuclear damage is covered by the 1983 Nuclear Energy Liability Act. Operators have unlimited liability, and they need to maintain CHF 1 billion in insurance coverage. Switzerland has signed, but not ratified, the IAEA Vienna convention and the OECD Paris and Brussels conventions. Swiss legislation is under revision with the target to ratify the recently revised Paris and Brussels conventions.

Non-proliferation

Switzerland is a party to the Nuclear Non-Proliferation Treaty (NPT) as a non-nuclear weapons state. Its safeguards agreement under the NPT came into force in 1978. It is member of the Nuclear Suppliers' Group but not of Euratom. In 2000 it signed the Additional Protocol in relation to its safeguards agreements with the IAEA.

Main References:
IAEA 2002, Country Nuclear Power Profiles
NAGRA & Zwilag websites