Oskarshamn Nuclear Power Plant

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Oskarshamn Nuclear Power Plant
Oskarshamn NPP
Coordinates57°24′56″N 16°40′16″E / 57.41556°N 16.67111°E / 57.41556; 16.67111Coordinates: 57°24′56″N 16°40′16″E / 57.41556°N 16.67111°E / 57.41556; 16.67111
Construction began1965
Commission dateO1: February 6, 1972
O2: January 1, 1975
O3: August 15, 1985
Decommission dateO1: June 17, 2017
O2: October 14, 2015
Owner(s)OKG AB
Operator(s)OKG Aktiebolag
(Uniper SE 54.5%,
Fortum 45.5%)
Nuclear power station
Cooling sourceKalmar Strait
Power generation
Units operational1 × 1,450 MWe
Units decommissioned1 × 494 MWe
1 × 664 MWe
Capacity factor68.9%
Annual net output15,736 GWh
External links
CommonsRelated media on Commons
Oskarshamn reactor O1, O2 and O3.

The Nuclear power station Oskarshamn is one of three active nuclear power stations in Sweden. The plant is about 30 kilometers (19 mi) north of Oskarshamn, directly at the Kalmarsund at the Baltic Sea coast and with three reactors producing about 10% of the electricity needs of Sweden. All reactors use BWR technology.

Unit 1 had an installed output of 494 MW and Unit 2 664 MW; these are now decommissioned. Unit 3, the newest reactor block at the facility, has an installed output of 1,450 MW.

Clab, the temporary storage facility for spent nuclear fuel from all Swedish reactors, is also located at the site.


The responsible utility is OKG, short for the Oskarshamnsverkets Kraftgrupp OKG, which was acquired by Sydkraft in 1993, (later: E.ON Sverige). Uniper owns 54.5% and the other partner Fortum 45.5% of OKG.


On July 25, 2006, Units 1 and 2 were shut down as a precaution after a safety-related incident at an identical reactor at the Forsmark plant. The incident related to a failure of diesel generators to automatically start up when required, after a blackout caused by a shortcut at the grindgear sections at the plant. Modifications were later made to all the plants to address the issue.[1]

On May 21, 2008, a welder was caught on the entrance security check with trace elements of explosives on a carrier bag and his hand. The same evening Reactor 1 of the facility was shut down to allow bomb teams to sweep the facility. With police investigations ongoing, Kalmar police spokesperson Sven-Erik Karlsson confirmed to the TT news agency that a welder on his way in to the plant on Wednesday morning was caught with a relatively small amount of a highly explosive substance. The substance was later shown to be from nail polish and the event had no relevance to the operation of the plant or nuclear safety.[2][3][4]

During 2010 Unit 2 underwent power and security upgrades. Unit 3 was after many upgrades the most powerful BWR in the world at approximately 1450 MWe. Due to the upgrade, the reactor had been on and off the grid with prolonged maintenance outages throughout 2010.[5] Unit 2 will be upgraded in several steps and will reach maximum capacity of thermal power 2,300 MW and 840 MWe in 2011.[6]

On September 30, 2013, a portion of the plant (the third reactor) was closed when a group of jellyfish clogged the cooling water intake pipes. It was not indicated as to whether the event had been classified as a safety disturbance yet, and to what level on the scale used for nuclear plants.[7]

A decision on premature shutdown of units 1 and 2 was made in 2015. The decision entails that there will be no future investments at unit 2 and the reactor will not be restarted.[8][9]

Unit 1 was originally set for decommissioning on June 29, 2017, but it was closed prematurely due to an "operational disturbance" on June 17, 2017. It was decided not to restart the unit ahead of the shutdown scheduled for June 29, 2017.[10]

In December 2018 a strategy was outlined for the "radiological demolition" of units 1 and 2 to be carried out between 2020 and 2028. This will allow the land to be used for other nuclear power related purposes.[11]

See also[edit]


  1. ^ "Forsmark under scrutiny". World Nuclear News. 30 January 2007. Retrieved 1 May 2010.
  2. ^ Leknes, Knut H. (21 May 2008). "Bombefrykt tones ned". Aftenposten (in Norwegian). Archived from the original on 23 September 2012. Retrieved 6 August 2012.
  3. ^ Jersler, Titti (21 May 2008). "Två anhållna misstänkta för förberedelse av sabotage mot Oskarshamns kärnkraftverk". Aftonbladet (in Swedish). Retrieved 6 August 2012.
  4. ^ "Two arrests in nuke plant bomb plot". The Local. 21 May 2008. Retrieved 6 August 2012.
  5. ^ "The Production Year 2010 – Production Records despite Setbacks". OKG. 17 January 2011. Retrieved 6 August 2012.
  6. ^ "Approval for Oskarshamn 2 uprate". World Nuclear News. 30 April 2010. Retrieved 1 May 2010.
  7. ^ Gary Peach (2 October 2013). "Wave of jellyfish shuts down Swedish nuclear reactor". MSN News. Retrieved 2013-10-04.
  8. ^ "About OKG". OKG Aktiebolag. 26 July 2017. Retrieved 24 December 2017.
  9. ^ "OKG - Oskarshamn 2". OKG Aktiebolag. 26 July 2017. Retrieved 24 December 2017.
  10. ^ "Oskarshamn 1 enters retirement". World Nuclear News. 20 June 2017. Retrieved 2017-06-24.
  11. ^ "Uniper to coordinate demolition of Swedish reactors". World Nuclear News. 21 December 2018. Retrieved 22 December 2018.

External links[edit]