Approval for Oskarshamn 2 uprate

30 April 2010

The Swedish government has approved OKG's plans to increase the electrical generating capacity of Unit 2 of the Oskarshamn nuclear power plant by almost 38%.


Oskarshamn 2 (OKG)
Oskarshamn 2 (Image: OKG)
The thermal power output of the boiling water reactor (BWR) will be increased from 1800 MW to 2300 MW. An increase in the thermal effect, together with efficiency gains in the turbine plant, means that the electrical output of the plant will increase from 610 MW net to 840 MW net.


OKG has been preparing for the uprate since 2007 when new electrical and control systems were installed. The turbine hall is currently being modernized and in 2011 safety systems will be upgraded and the unit can start delivering the higher power. In addition to this, a new turbine control system will be installed and consequently the control room will be redesigned.


OKG's plan to uprate the unit had already been approved by the Swedish Radiation Safety Authority (SSM) and the Environmental Court.


Siemens Power Generation won a contract in June 2007 to upgrade the low-pressure turbines at Oskarshamn 2. The new turbines will use advanced three-dimensional blading technology, enabling them to make better use of the energy contained in the steam produced by the reactor. As well as the low-pressure turbines, Siemens will supply other related components and a new instrumentation and control system.


Oskarshamn 2 is one of three BWRs at the site, operated by OKG, itself a Swedish subsidiary of EOn. It entered commercial operation in 1975. Unlike a pressurised water reactor, steam from a BWR is fed directly to the turbines without passing through a heat exchanger.


In 2005, the Swedish regulator approved a 250 MWe uprate of the Oskarshamn 3 reactor, to 1450 MWe net, this was confirmed by the government in January 2006, and in September 2009 SSM approved test operation at the uprated level. The SKr3.2 billion (€313 million) project involved turbine upgrade by Alstom, as well as reactor upgrade, and will extend the plant's life to 60 years.


Oskarshamn 1 has had three renovations and uprates, in 1995, 1998 and 2002. Its generating capacity now stands at 467 MWe net.


Researched and written

by World Nuclear News