Oskarshamn 1

The story of nuclear power on the Simpevarp peninsula a few miles outside Oskarshamn begins on July 14, 1965. That's when an order was placed with Asea for Sweden's first light water reactor. A nuclear power plant is not something that can be set up in a few months; it took six years before the plant could be phased into the power grid. Oskarshamn 1, known as O1, was officially inaugurated in 1972.

Between 1993 and 1995, an extensive renovation of O1, called Project Phoenix, took place. The project attracted a lot of attention because it was the first time work had been carried out inside a reactor vessel that had been in operation. At the same time, the reactor's future modernization needs were investigated, resulting in the Max and Mod projects.

Max, in 1998, included the replacement of the moderator tank, moderator tank cap and steam shell valves - all significant parts of the reactor. The Mod project, carried out in 2002, introduced a new safety concept, a new control system and reactor protection system, rebuilt the control room and installed a new turbine. The result was an efficiency improvement of 22 MW.

Thirteen years later, on October 14, 2015, the then majority owner decided on the early closure of both O1 and O2. The closure of O1 started on Saturday, June 17, 2017, when the plant delivered its last kilowatt hours of electricity.

Quick facts about O1

• Construction started: 1966
• Start of operation: 1972
• Maximum gross capacity: 492 MW
• Net maximum power: 473 MW
• Thermal capacity: 1 375 MW
• Best production year: 2014 with 3.5 TWh
• Decommissioned: 2017
• Total production: 109 TWh