Nuclear Power Plants in Sweden during the Last 40 Years
The Swedish nuclear power programme began with the commissioning of light water reactors which were brought into operation between 1972 and 1985. Together they produced about half of the Swedish electricity demand – currently about 40%. Almost all the rest was provided by hydro power stations currently supported by wind power units, making the Swedish electricity power production almost completely free of fossil fuels. This was also one of the primary aims of the nuclear power implementation and the rate of adding new plants. The Swedish program is by far the world’s fastest program ever to establish CO2-free electricity production.
The figure to the above shows the power added to the grid by the nuclear power units. (Note: the power has since the original startup been increased in all but the first unit).
The first figure on the next page shows how these units were constructed and taken into operation. The program as a whole must be considered a success considering the short construction times. As explained later the results were achieved despite considerable political turmoil in an era when safety requirements were developing very quickly – the regulatory environment was volatile to say the least.
The accumulated energy produced in the Swedish nuclear power plants reached more than 2100 TWh by the end of 2014. This is more than 15 times the yearly electric energy consumption in Sweden. The second figure on the next page shows the accumulated electric energy delivered by the Swedish units.
There was essentially a national consensus on building nuclear power plants until the change in government in 1976. An anti-nuclear government lead by the Center Party took over with the aim to stop further increase in the use of nuclear power. Agreement could however not be reached and the only result was a new law (1977) requiring the operators/licensees to show means of taking care of the irradiated fuel and highly radioactive waste in order to be allowed to load fuel into the reactors. According to the law one could use reprocessing and then store the waste or store the irradiated fuel in a final depository. This law (Law on Conditions to Load Fuel – Villkorslagen in Swedish) was one reason for the power companies to establish SKB (Swedish Nuclear Fuel and Waste Management Company) to organize, and establish means and facilities for the handling of waste and irradiated fuel from the Swedish nuclear program. SKB established the KBS-1 method for use of reprocessing and then storing the waste, and the KBS-2 (later developed to KBS-3) method of storing the irradiated fuel without reprocessing. The Act on Nuclear Activities established in 1984 eliminated the conditional law. A general consensus emerged on not using reprocessing as a means to reduce the storage requirements. The KBS-3 method was endorsed as the future means. Currently, Swedish authorities are reviewing an application from SKB regarding a final repository for high-level nuclear waste based on the KBS-3 method. Once approved Sweden will probably be the second country (next Finland) to take a final repository into operation.
Above - Construction of the 12 Swedish Nuclear Power Units. Below – Energy delivered by the Units.
Following the Three Mile Island accident in 1979, the government decided to have a national referendum on the use of nuclear power. Voters could choose among three alternatives. All alternatives included that nuclear power should be abandoned. Alternative 1 stated that this should be done after using those already built and in the process of being built, when suitable alternatives were available. Alternative 2 was essentially identical, but included also some statements on ensuring safety and avoiding the use of oil and coal. It also claimed that excessive profits from hydro power supply should be heavily taxed. Alternative 3 stated that only those in operation should be used for a maximum of 10 years and those under construction should be stopped. Together, alternatives 1 and 2 draw about 60% of the votes. More than 75% of those who were allowed to vote did so. Following the referendum the parliament decided that all units should be stopped latest 2010, when the last units to be built (OKG3 and Forsmark 3) would be 25 years old.
As shown in the figure on the previous page, all 12 units were finalized and taken into operation with some delay due to the referendum. The decision that all units should be closed by 2010 hampered the industry for years until it was abandoned in 1997 following an agreement to permanently close the Barsebäck units. These two units were then closed in 1999 and 2005.
The Act on Nuclear Activities was changed in 1987 such that it was not allowed to provide a permit to build a new nuclear power unit. It was even unlawful to carry out a project with the purpose of building a new unit. This part of the law was eliminated in 2006 by a new government.
In 2010 the laws were changed such that new nuclear power units may be built provided that the new unit replaces an older unit that is permanently shut down.
Nine out of the twelve units built in Sweden were delivered by ASEA-ATOM (later ABB and now Westinghouse Sweden). A major part of the success of the program was the fact that most major parts of the plants were delivered by one and the same company (ASEA) reducing the depth of supply chains and facilitating contracting and decision making. Most parties involved also had extensive previous experience of constructing large power plants. The pace of building the units also allowed for feedback and re-use of experiences. Delivery of the units was efficient by having mostly domestic suppliers or suppliers with a stronghold in the country or nearby. This applied also to the Westinghouse delivery of Ringhals 2, 3 and 4.
The electricity prices were low between 1997 and 2003 following the deregulation of the electricity market. This impacted on the economy of the nuclear power plants and some maintenance was delayed resulting later in loss of availability. In addition, a planning horizon of year 2010 was a consequence of the earlier parliament decision.
Since 1984 there is a special tax on nuclear power. From year 2000 onwards it is a tax related to the power production capability of the unit, regardless of the energy produced. The tax is currently about 20% of the total production costs for the nuclear power plants. Another 17% increase is decided to increase the tax to 14 770 SEK (1600 EUR) per MW thermal power and month.
Significant safety enhancements have been introduced to the plants following the Three Mile Island accident, the Chernobyl accident and as a result of more challenging safety requirements. Additional safety improvements will be introduced to protect against very unlikely events as deduced from the Fukushima event. Temporary actions are to be implemented by end of 2017 and permanent implementations should be operable by end of 2020.
Electricity prices have decreased substantially and are estimated to remain low, partly since subsidized power generation facilities are introduced into the system. A result is that Vattenfall and E.ON being majority owners of Ringhals and OKG respectively, have decided to shut down the Ringhals 1 and 2 units, and the OKG 1 and OKG 2 units (in Oskarshamn). They are all considered unprofitable in the future. The OKG2 unit will not restart from a large scale upgrade work. The exact dates of closure for the other three units have not been set, but are within a few years from now. The remaining six units will continue operating until 60 years of age according to current planning. However, Vattenfall has in the beginning of 2016 announced that it might be necessary to shut down also its remaining five units if not the nuclear power tax is removed.
Following the law change in 2010 permitting new builds, Vattenfall investigated a new build for replacement purposes. This project was later stopped due to the low electricity prices, low needs for additional generation capacity for the near future and the change in government in 2014 resulting in some changes of the owner’s directions to Vattenfall.
Looking forward, the electricity prices will only marginally increase according to current prognoses. The six nuclear units that remain following the planned shutdown of four units will be instrumental in providing stable and weather independent energy supply. They will also be important for ensuring the power balance in the grid, in particular in the south of Sweden. The Government has initiated a parliamentary Energy Commission with the mission to find a broad agreement on long term conditions for the national energy supply. The result of the Energy Commission, to be presented on Jan 1 2017, will hopefully make the future more clear with respect to electricity market conditions, responsibilities and the political view on the energy production portfolio.
Al in all, the Swedish nuclear power program has been a success in providing low cost and reliable base power to the consumers. Furthermore, the CO2 emissions avoided are considerable – more than 2 Gton if coal would have been the alternative.
Nils-Olov Jonsson and Carl Berglöf
Swedish Nuclear Society