In 2005 Forsmark applied for permission to increase the boiling water reactor unit’s thermal capacity to 3,253 MWt. The government granted permission for the power increase in 2010.
However, it set a condition that the plant could not begin test operation or routine operation without SSM’s approval. SSM approved test operation in 2012 before Forsmark applied for routine operation at the higher power level in 2015.
SSM then asked for additional information as part of the application. Forsmark submitted supplementary information in several batches from 2017 to 2019.
The plant’s initial thermal capacity when it began commercial operation in 1981 was 2,711 MWt. Its initial net electric output capacity, now 1,118 MW, was 900 MW.
The Forsmark station has three BWRs which produce about one sixth of all electricity used in Sweden.