Nuclear Power in Switzerland

(January 2010)

• Switzerland has 5 nuclear reactors generating 40% of its electricity.
• Its first commercial nuclear power reactor began operating in 1969.
• A national vote has confirmed nuclear energy as part of Switzerland's electricity mix.

Electricity consumption in Switzerland has been growing at about 2% per year since 1980. In 2007 electricity production was 68 billion kWh gross, mostly from nuclear and hydro, requiring 2.5 TWh net import to match demand – less than previous years. A lot of electricity is imported from France and Germany and up to 26 TWh/yr exported to Italy. Per capita consumption is 7650 kWh/yr. In 2007 nuclear power contributed 26.5 TWh net, 43% of Swiss demand.

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).

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 Liebstadt.

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.

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 Liebstadt from 942 MWe.

All Swiss reactors have unlimited-duration operating licences, following that granted to Muehleberg in December 2009.

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

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

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 2006 it was reported that ATEL was looking for partners to build a further large nuclear power plant using proven technology and probably at an existing nuclear plant site. Axpo Holding AG has 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 a 355 MWe hydro plant, effectively removing 2400 MWe.

In 2007 the Resun joint venture was formed by NOK (57.75%), BKW FMB Energie (31.25%) and Centralschweizerische Kraftwerk (11%) to apply to construct two identical reactors of up to 1600 MWe each at Beznau and Muhleberg site. ATEL has been invited to join the venture.

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 is envisaged, with hybrid cooling system which will minimize water use. Estimated cost is EUR 3.7 to 4.5 billion to be shared by partners, and start-up is 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 is pursuing this.

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 reactors are envisaged, and as with the Gosgen replacement, they will be advanced 1100 to 1600 MWe types, with hybrid cooling system to minimize water use.

The Federal Office of Energy is reported to favour construction of two new reactors, not three.

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. Target date for repository operation is 2020.

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 Zwilag in Würenlingen. It is packaged into suitable containers and then stored in facilities at the power plants or at Zwilag. 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 Zwilag. (A container is around 6 metres high and 2.5 metres diameter.)

Total costs of radioactive waste management are estimated at CHF 11.9 billion. Nuclear plant owners have paid CHF 8.2 billion towards final waste management and now pay into a national waste disposal fund created in 2000, which held CHF 2.76 billion at the end of 2005.

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 two funds held a total of CHF 4.3 billion at the end of 2006.

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 (HSK) monitors and regulates both safety and radiological protection in nuclear installations. It was set up under the Federal Energy Office in 1982, and since 2003 there have been legislative moves to make it independent. This will fully come bout in 2009.

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 web sites

參考來源:World Nuclear Association