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Isar 1 nuclear power plant

© E.ON Kernkraft GmbH, Gelände des Kernkraftwerk Isar (KKI), cropped by BMU, CC BY-SA 3.0


Isar 1 nuclear power plant in Bavaria is operated by PreussenElektra GmbH. Commercial operation began in 1979. The plant was shut down on 17 March 2011. Authorisation for power operation in accordance with the German Atomic Energy Act (AtG) expired on 6 August 2011. The Bavarian State Ministry of the Environment and Consumer Protection as the competent nuclear authority in Bavaria granted the first licence for decommissioning and dismantling according to section 7 (3) AtG on 17 January 2017.


General information

Federal stateBavaria
Type (construction line)Boiling water reactor (construction line 69)
Current operatorPreussenElektra GmbH 
OwnerPreussenElektra GmbH 

Operational data

Application date21 December 1970
Start of construction1 May 1972
First criticality20 November 1977
First grid synchronisation3 December 1977
Start of commercial operation21 March 1979
Shutdown date17 March 2011
Expiry of authorisation for power operation in accordance with the German Atomic Energy Act (AtG)6 August 2011
First decommissioning and dismantling licence17 January 2017

Technical data

Thermal reactor power2,575 MW
Gross electric capacity912 MW
Net electric capacity878 MW
Number of control elements145
Type of cooling systemDirect river cooling