Oskarshamn 1

Oskarshamn 1 is Sweden's first commercial nuclear power plant. An order was placed to the company formerly known as Asea on July 14th, 1965. The plant was connected to the electric power grid for the first time in 1971 and inaugurated in 1972. An extensive renovation of O1, called project Fenix, was ongoing between 1993 and 1995. Project Fenix drew a lot of attention since it was the first time work was done on a reactor while it was in operation. An investigation was also completed during the project to evaluate any future need for modernisation. This in turn led to two additional modernisation projects, called Max and Mod.

Project Max was completed in 1998 and was carried out in five different stages, which involved changing the moderator-tank, the moderator-tank upper head and the steam containment isolation valve. Project Mod was carried out in 2002 and included a new safety concept, a new reactor control system and reactor protection system, along with a renovation of the control room and a new turbine. Changing the turbine resulted in a 22 MW efficiency increase.

At an extraordinary shareholders' meeting held in October 2015, OKG's majority owner upheld their policy decision on the premature shutdown of units O1 and O2. On 17 June 2017, unit O1 delivered its final kilowatt hours of electricity. Read more in pressrelease.

A few facts

Construction began: 1966
Start-up: 1972
Gross output: 492 MW
Highest annual production: 3.5 TWh in 2014
Shutdown: 2017
Total production: 109 TWh