Leibstadt nuclear power plant

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Leibstadt nuclear power plant
Leibstadt nuclear power plant
Leibstadt nuclear power plant
Leibstadt nuclear power plant (Canton of Aargau)
Leibstadt nuclear power plant
Coordinates 656 036  /  272 562 coordinates: 47 ° 36 '5 "  N , 8 ° 11' 2"  O ; CH1903:  six hundred fifty-six thousand and thirty-six  /  272,562
height 341  m
Country: Switzerland
Owner: Leibstadt AG nuclear power plant
Operator: Leibstadt AG nuclear power plant
Project start: 1972
Commercial operation: Dec 15, 1984

Active reactors (gross):

1 (1275 MW)
Energy fed in in 2015: 8,599 GWh
Energy fed in since commissioning: 262,182 GWh
Website: Website of the nuclear power plant
Was standing: Dec 21, 2016
The data source of the respective entries can be found in the documentation .

The Leibstadt nuclear power plant , or KKL for short , with a BWR-6 boiling water reactor from General Electric with 1220  MW electrical net output, is located in the municipality of Leibstadt ( canton Aargau , Switzerland ) on the Rhine near the mouth of the Aare and the German border at Waldshut- Tiengen across from the village of Dogern . It went into operation at the end of 1984, making it the youngest of the five nuclear reactors in Switzerland. It generates one sixth of the electricity generated in Switzerland. Sixty years of operation is (as of 2014) conceivable.


The cooling takes place through a 144 meter high natural draft wet cooling tower .

The power plant is operated by Kernkraftwerk Leibstadt AG (KKL). Six Swiss energy companies have a stake in the company: Alpiq AG with 27.4 percent, Alpiq Suisse SA with 5 percent, Axpo Power AG with 22.8 percent, Centralschweizerische Kraftwerke AG (CKW) with 13.6 percent, the Axpo Solutions AG (formerly EGL) with 16.3 percent, BKW Energie with 9.5 percent and AEW Energie with 5.4 percent. The management was originally held by EGL; the establishment of Axpo Holding consolidated the areas of responsibility within the Axpo Group, which means that Axpo Power AG is now in charge of the management. It also takes care of the power transmission to Laufenburg and Beznau at the 380 kV voltage level (see Elektrizitätsgesellschaft Laufenburg and here ) .

The conical chimney is almost white in color, with a checkerboard-like red contrast marking in the upper area. The narrow, gray south front of the machine house, which faces the open-air switchgear , shows in orange a curve made up of 6 rectangular elements that rises progressively to the right and whose individual (but also added) heights correspond to the Fibonacci sequence . The long sides of the machine house and the adjoining structures are painted turquoise.

In the 144 m high cooling tower, 33 cubic meters of water rush down 12 meters per second in order to cool down in the countercurrent of air also through evaporation.


The nuclear power plant under construction

Planning of the Leibstadt nuclear power plant began in 1964 on the basis of a 600 MW system with river water cooling. When river water cooling was banned by the Federal Council in 1971, a solution with a cooling tower was required. In the further course of the planning, the output was increased from 600 to 900 MW.

As a result of the reactor accident at the Three Mile Island nuclear power plant in 1979, new safety regulations were issued that delayed completion by several years. Instead of the budgeted two billion francs, the power plant ended up costing over 4.8 billion.

In 1984, after eleven years of construction, the plant was able to start operating. On December 15, 1984, it became the fifth Swiss nuclear power plant to go into continuous operation. After Beznau I, Beznau II, Mühleberg and Gösgen, Leibstadt is the youngest and most powerful nuclear power plant in Switzerland. Since 1984 it has produced around one sixth of the electricity consumed in Switzerland. That corresponds to around 29 million kilowatt hours every day.

The history of the completion of the KKL reflects the increasingly critical attitude towards nuclear energy in Switzerland during the 1970s and 1980s, which culminated in the dispute over the Kaiseraugst nuclear power plant project .

Presentation of the story by the KKL

The website of the power plant reports on the chronicle sub-page with entries up to 2014.

In 1973 the federal government issued a site permit for a gross output of 940 MW. KKL AG is founded on November 26, 1973. The contract for the construction was placed on December 1, 1973 and the main facilities (reactor and machine house) went to a consortium of Brown Boveri & Cie. (BBC), Baden, Switzerland and General Electric (GE), USA. Elektrowatt AG is in charge of the construction of the ancillary facilities (including cooling tower, workshop, office building). In 1977 training courses for operating personnel begin in the USA and Spain. Construction delays beyond the start of operations planned for 1978 are used to learn from the accident in Harrisburg (1979). In 1982 the staff went to shift work, and on December 15, 1984, continuous operation of power generation was started.

A few months after the Chernobyl reactor accident, the signature collections for two new anti-nuclear initiatives began in 1986. In 1990, the popular initiative for an exit from nuclear power was rejected with 52.9% of the votes against, the moratorium not to approve any further nuclear power plants, however, accepted with 54.5%. The energy article in the federal constitution is accepted with 71.1% yes.

In 1994 a new, interactively equipped information center with a cylindrical glass facade and a central reactor model replaced the visitor center from 1974. Free guided tours are offered. In 1995 the plant received its own training simulator, which replaced trips to Spain. From 1998 to 2003, the net output is increased from 960 to 1165 MW in two steps in dialogue with the control authority. 77.6% of the 2003 nuclear phase-out initiative is rejected in the canton (Aargau), even more so in the Zurzach district with 85.4% and the Leibstadt community. The 2003 moratorium initiative was also clearly rejected. In 2003, NOK (Axpo) took over management of the KKL from EGL.

In 2004, KKL AG announced the decrease in the production costs of electricity production from originally 9.23 to 5 cents per kWh - including 1 cents for the shutdown of the plant and the disposal of waste. In 2005 the plant was shut down for five months due to a non-nuclear defect; After a ground fault in the generator stator, parts must be replaced. 3000 visitors come to the information days in May 2006.

In 2008, the cooling water circuit was doped with hydrogen and platinum in accordance with a new procedure from GE in order to protect the reactor and its internals from stress corrosion cracking. In 2009 there were 470 employees and 14 apprentices, 20% of them from countries near the border. In 2010, a generation change in the workforce will be initiated by double appointments to transfer know-how. In 2010, the system will be shut down for an overhaul period longer than 47 days, during which important large components (block transformer, 2 low-pressure preheaters and 3 low-pressure turbines) will be replaced, increasing efficiency and increasing the yield by 40 MW. After the reactor accident in Fukushima in 2011, the KKL provided the safety evidence required by the Federal Nuclear Safety Inspectorate (ENSI). In 2012, the EU stress test was passed with above-average results and the most extensive annual major revision to date was carried out, during which the generator was replaced and the gross nominal output increased to 1275 MW.

In 2013 the plant achieved 93% availability and its highest annual electricity production to date of 9692 GWh. In 2014, 250,000 GWh of electricity production accumulated over 30 years of operation.

Current Press Releases

As part of the planned fuel inspections during the main annual overhaul in 2016, local discoloration of the cladding of the fuel rods was discovered on some fuel assemblies. This led to a prolonged downtime of the plant. The local discolorations on the cladding tubes of the fuel assemblies turned out to be oxidation. Oxidation on fuel rods is a normal process in a boiling water reactor. A layer of zirconium oxide forms on the zirconium cladding tubes in conjunction with the water in the reactor core. However, in 2016 these had progressed so far that it was not possible to reuse the fuel elements concerned for a further production period. Other affected pipes were found by measuring the thickness of the oxide layer. Of the total of 648 fuel elements in the reactor core, 47 fuel elements were discolored in places. Only fuel elements in the first operating cycle (year) are affected. The repair was partly carried out by replacing the cladding tubes with massive zirconium rods without uranium content. As a result, the reactor had to be redesigned and reloaded. This is accompanied by extensive calculations and safety analyzes, and a permit for recommissioning is required. After ENSI granted approval for the next operating cycle subject to certain conditions, the plant went back online on February 17, 2017. The reactor was shut down again due to a malfunction of the exhaust system (a defect in a suction line of the turbine condenser). After the exhaust system in the machine house had been successfully repaired, the power plant was gradually started up on February 20, 2017 and synchronized with the power grid at 5.10 p.m. In order to prevent new oxidations from occurring, the operator was ordered to run the system with a reduced total output of 90%.

On September 18, 2017, the NPP was taken off the grid for the exchange of 76 of the 648 fuel elements as well as for various tests, revision and maintenance activities (for a planned seven weeks). The fuel elements that were recently used were also specially checked. In addition, the two water separator reheaters will be renewed, two large components in the non-nuclear area, each made up of two individual parts, each weighing 130 tons . During the main annual revision, 1,600 external specialists support the 500 usual NPP employees.

As early as October 19, it was announced that the replacement of the fuel elements would take a week longer. On October 30, the deadline was extended by another four days. At a fuel supplier to the nuclear power plant, 16 non-specification fuel elements were found. These elements were intended for the next operating cycle. The NPP is expected to go back online on November 17th. On November 8, however, it was announced that a further 8 (later corrected to 6) faulty fuel elements had been found and that the NPP would probably be shut down until the end of the year, as the replacement of the fuel elements would require a redesign of the reactor core and a comprehensive approval process by the supervisory authority would make necessary. These 6 fuel elements have already been in use for 3 to 4 years - “without any problems”, as the operators immediately insured. Nevertheless, they have now been replaced as a precaution. The 16 remaining fuel elements with “quality assurance errors” had not yet been inserted.

On August 25, 2019 first reported by media that the ENSI of since 2015 ongoing personnel reduction will be examined in the NPP, in terms of number of incidents down.


Cooling tower
Overall view of the power plant

On August 11, 1995 at 8.22 a.m., a hydrogen deflagration occurred in the Leibstadt nuclear power plant during the overhaul work. Two employees suffered third degree burns. The fitters wanted to check part of the auxiliary steam system in the machine house. They opened a lid on one of the containers; the escaping hydrogen ignited. In normal operation there is live steam in the affected system, which comes from the reactor and is therefore contaminated. The accident took place in the non-nuclear part of the facility.

On March 28, 2005 the power plant was shut down due to an earth fault in the generator. During the early overhaul , there was an INES level 1 incident. On September 2, the power plant was back on the grid.

In 2007 the Leibstadt NPP reported three incidents to the federal nuclear supervisory authority . While the supervisory authority, the Main Department for the Safety of Nuclear Facilities (HSK), classified two of the incidents as incidents with little or no safety relevance, they classified the reactor shutdown due to faulty triggering of the automatic pressure reduction system on March 6, 2007 at INES level 1 as Disturbance, d. H. a deviation from the permissible ranges for the safe operation of the system.

During the 2010 annual inspection, an incident (INES-2) occurred in which an employee's hand was exposed to radiation and the annual dose limit for hands was exceeded.

In July 2014 it was discovered by chance that in 2008 external personnel had already drilled a total of six wall-penetrating holes through the primary containment to attach fire extinguishers . After their discovery, they were initially temporarily sealed. The process was sharply criticized by the Swiss nuclear safety authority ENSI : Such an incident should not happen and indicates a "significant deficit in the organizational area". The incident was rated 1 on the INES scale . The repairs were accepted by ENSI on July 18, and the authorities also want to review the measures taken by the nuclear power plant to prevent such incidents in future.

As early as 2014, oxidation and leakage of radioactivity into the water cycle occurred on a cladding tube, which ENSI will publish on February 1, 2017.

As part of the planned fuel inspections during the main annual overhaul in 2016, local discoloration of the cladding of the fuel rods was discovered on some fuel assemblies. This led to a prolonged downtime of the plant. The discoloration on the fuel elements is due to oxidation. The oxidation points were local, between 3 and 4 millimeters to 25 centimeters long and were located on the upper part of the approximately four meter long fuel rod.

The ultimate cause of the oxidation, which ENSI classified as an INES category 1 occurrence, has not yet been clarified. Under ENSI requirements, the reactor went back on line with a reduced output in the course of February 17, 2017, but was shut down again the following night due to a malfunction in the exhaust system in the non-nuclear area. After the exhaust system in the machine house had been successfully repaired, the power plant was gradually started up on February 20, 2017 and synchronized with the power grid at 5.10 p.m.

On April 26, 2019 and May 12, 2019, the nuclear power plant was disconnected from the grid due to malfunctions in an inlet pressure regulator. On July 4, 2019, the plant had to be shut down due to an oil leak. On December 28, 2019, the nuclear power plant was taken off the grid for three days again due to a technical malfunction.

Emissions data

The Leibstadt NPP must publish the exhaust air data. November 2014 had Greenpeace at ENSI , based on the Freedom of Information Act , access to the air data at the cooling tower requires the KKL for the period from 1 January 2013 to November 1, 2014. At the time, ENSI informed Greenpeace that it no longer had this data and that the Leibstadt nuclear power plant was not ready to supply it again. After conducting an arbitration process , the FDPIC recommended in October 2015 that ENSI obtain and publish the data from the KKL. Kernkraftwerk Leibstadt AG then demanded a contestable ruling from ENSI and lodged a complaint with the Federal Administrative Court , which gave it the full right. Greenpeace appealed against the judgment of the Federal Administrative Court to the Federal Supreme Court in August 2016 . The Federal Supreme Court corrected the lower court ruling and gave Greenpeace the right and, on September 27, 2017, obliged the KKL to grant Greenpeace access to the emission data for the required period. The federal court opted for transparency. In this case, the Federal Nuclear Safety Inspectorate, ENSI, decided that it would not only send the data provided by KKL to Greenpeace, but also publish it. During this period, the KKL always complied with the delivery limits.

Protest actions

The Leibstadt nuclear power plant has been the scene of protests several times:

On 29 March 1998 sealed activists from Greenpeace on the grounds of the power plant a prepared for loading transport containers and occupied the loading crane. Greenpeace called on Kernkraftwerk Leibstadt AG (KKL) to forego the current transport and to stop reprocessing , as Switzerland is guilty of radioactive contamination of the sea and the area around the La Hague reprocessing plant by exporting spent fuel elements .

On November 13, 2000, Greenpeace held a vigil on the factory tracks to protest against the transport of nuclear waste from Leibstadt to La Hague. Shortly before the protest, the Swiss Federal Prosecutor's Office ordered a criminal investigation against the KKL and the responsible authorities.

On March 13, 2003, Greenpeace activists climbed the cooling tower, among other things, and unfolded a banner with the words “No need”. Around 60 activists from eight countries who had invaded the factory premises took part in the campaign. With their protest on the cooling tower and the chimney, they drew attention to the fact that Switzerland (2003) exports (e) the same amount of electricity abroad as the Leibstadt nuclear power plant (or the oldest nuclear power plants in Beznau and Mühleberg together) produce.

Reactor pressure vessel

Parts of the reactor pressure vessel (RPV) of the KKL were manufactured by Rotterdamsche Droogdok Maatschappij (RDM). In mid-August 2012 , cracks were discovered in the RPV of Unit 3, which was manufactured by RDM, in the Doel nuclear power plant in Belgium . The NEA then published a list of 22 reactors whose pressure vessels RDM was involved in the manufacture. Mühleberg and Leibstadt were on this list . According to the ENSI supervisory authority , the RPV in Leibstadt is not affected because it differs from the Belgian reactors in terms of both the manufacturer and the manufacturing process. For the cylindrical casing rings, the arched bottom and for the cover of the RPV, no forged, but hot-rolled material was used. The individual jacket rings were made in Japan and France from rolled plate material.

Data of the reactor block

The Leibstadt nuclear power plant has one block :

Reactor block Reactor type net
start of building Network
of essential operation
Leibstadt (KKL) Boiling water reactor 1220 MW 1275 MW 1st January 1974 May 24, 1984 15th December 1984 So far unlimited

See also

Web links

Commons : Leibstadt nuclear power plant  - collection of images, videos and audio files

Individual evidence

  1. Homepage KKL ( Memento of the original from March 18, 2017 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.kkl.ch
  2. A lot of time for the nuclear phase-out ; Report in the NZZ
  3. Technical details of the Leibstadt nuclear power plant  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / www.kkl.ch  
  4. Annex, detailed recording 008 kkl.ch, accessed February 19, 2017.
  5. kkl.ch
  6. www.kkl.ch> KKL> Chronik ( Memento of the original from February 19, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 19, 2017. @1@ 2Template: Webachiv / IABot / www.kkl.ch
  7. Press release: Extension of the main annual revision. August 22, 2016. Retrieved February 19, 2017.
  8. Media releases> Archive ( Memento of the original from February 20, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 1997-2016, notices accessed February 19, 2017. @1@ 2Template: Webachiv / IABot / www.kkl.ch
  9. ensi.ch
  10. badische-zeitung.de , September 21, 2017: Seven weeks off the network (October 2, 2017)
  11. Leibstadt nuclear power plant: No further oxidations on fuel elements - cause analysis is ongoing . aargauerzeitung.ch, October 19, 2017, accessed on November 17, 2017.
  12. Leibstadt nuclear power plant stays off the grid ten days longer - now new fuel elements have to be replaced . aargauerzeitung.ch, October 30, 2017, accessed on November 17, 2017.
  13. a b Leibstadt nuclear power plant paralyzed by the end of the year . Tagesanzeiger.ch, November 17, 2017, accessed on November 17, 2017.
  14. Other fuel elements with defects: Leibstadt nuclear power plant will remain offline until the end of the year . aargauerzeitung.ch, November 8, 2017, accessed on November 17, 2017.
  15. Leibstadt nuclear power plant: Six defective fuel elements were in use . aargauerzeitung.ch, November 17, 2017, accessed on November 17, 2017.
  16. ^ Nuclear power failure in Leibstadt. In: bluewin.ch . August 25, 2019. Retrieved August 25, 2019 .
  17. Susan Boos: Radiant Switzerland. Nuclear Industry Handbook. Rotpunktverlag, 1999.
  18. ensi.ch
  19. ensi.ch
  20. HSK: Classified incidents in Swiss nuclear power plants , accessed on February 20, 2008.
  21. HSK: Leibstadt reactor shutdown March 6, 2007 , accessed on February 20, 2008.
  22. ^ Incident at the Leibstadt nuclear power plant. In: NZZ Online from September 1, 2010.
  23. Leibstadt nuclear power plant: Explosive details emerged.
  24. ensi.ch
  25. Boreholes in the primary containment of the Leibstadt nuclear power plant . Press release from the Federal Nuclear Safety Inspectorate . Retrieved July 8, 2014.
  26. Holes drilled in the safety envelope: Nuclear supervisory authority strongly criticizes Leibstadt nuclear power plant . In: Aargauer Zeitung . July 7, 2014. Retrieved July 8, 2014.
  27. Leibstadt nuclear power plant: holes in the reactor shell went unnoticed for six years . In: Aargauer Zeitung, July 10, 2014.
  28. Leibstadt nuclear power plant fulfills ENSI requirements for repairing the containment. Federal Nuclear Safety Inspectorate , July 18, 2014, accessed on August 29, 2014 .
  29. ensi.ch
  30. a b Cooling failure in Leibstadt: cause of damage unknown - nuclear power plant should still be connected to the grid. February 1, 2017, accessed February 1, 2017 .
  31. The Leibstadt nuclear power plant is back on the grid - a standstill cost 180 million. Aargauer Zeitung, February 18, 2017, accessed on the same day.
  32. AKW Leibstadt produces electricity again after repairs http://www.aargauerzeitung.ch/schweiz/akw-leibstadt-produziert-nach-reparatur-wieder-strom-130994459
  33. Leibstadt nuclear power plant in Switzerland shut down for a short time. May 12, 2019, accessed May 12, 2019 .
  34. a b Helmut Stalder: Leibstadt nuclear power plant turns on again. In: nzz.ch. December 30, 2019, accessed December 31, 2019 .
  35. Due to a «technical malfunction» - Leibstadt nuclear power plant is offline. December 28, 2019, accessed December 28, 2019 .
  36. Neue Zürcher Zeitung : Administration also has to publish inconvenient things . September 27, 2017. Retrieved November 18, 2017.
  37. ENSI : Federal court ruling: ENSI publishes EMI data from the KKL for the required period . November 6, 2017. Retrieved November 18, 2017.
  38. Greenpeace Switzerland: Greenpeace prevents loading of illegal nuclear waste trains , accessed on March 9, 2008.
  39. Greenpeace Switzerland: Vigil at the Leibstadt nuclear power plant: Broad support for Greenpeace protest , accessed on March 9, 2008.
  40. ^ Greenpeace Switzerland: Big Greenpeace campaign in Leibstadt: Swiss nuclear power plants produce for foreign countries. Retrieved March 9, 2008.
  41. a b Inspections planned for 22 reactor pressure vessels. www.nuklearforum.ch, August 20, 2012, accessed on August 20, 2015 .
  42. Leibstadt nuclear power plant does not have to test reactor pressure vessels additionally. ENSI , December 2, 2013, accessed on August 20, 2015 .
  43. Power Reactor Information System of the IAEA : "Switzerland LEIBSTADT" (English)