Oskarshamn 1 enters retirement

Tuesday, 20 June 2017

Unit 1 of the Oskarshamn nuclear power plant in Sweden has been permanently shut down. A decision not to restart the unit after an operational issue resulted in it closing ten days ahead of schedule.

Unit 1 of the Oskarshamn plant (Image: OKG)

German utility Eon - the major shareholder in OKG AB - decided in October 2015 that units 1 and 2 of the Oskarshamn nuclear power plant in Sweden would be shut down permanently. At that time it said unit 1 would close between 2017 and 2019, and that there would be no future investments at unit 2 and the reactor would not be restarted. The company attributed the closure decision on low wholesale electricity prices, the burden of Sweden's tax on nuclear power and "additional requirements on extensive investments".

OKG announced in February 2016 that its board of directors had decided to shut down Oskarshamn 1 in conjunction with a planned outage at the end of this month.

However, the company announced yesterday that Oskarshamn 1 had suffered an "operational disturbance" on 17 June that led to its automatic shutdown. At a meeting yesterday, it was decided not to restart the unit ahead of the shutdown scheduled for 29 June.

There will be four phases to the decommissioning of Oskarshamn 1, OKG has said. In the first phase, fuel will be removed from its reactor and stored in its fuel pools for about one year, before being transported to Svensk Kärnbränslehantering AB's near-by used fuel facility at Clab. When all fuel has been removed from the unit, it will enter a phase of care and maintenance. Later on, physical dismantling and demolition of the unit will begin. Once the site is cleared and classified as free from radioactivity it can be used for other purposes.

Oskarshamn 1 is a 473 MWe boiling water reactor (BWR) that started up in 1972. The unit's production manager, Mikael Wramsjö, said: "The unit has been part of a unique journey during its 45 years of operation. Approximately 110,000,000 MWh of climate efficient electricity have been delivered to the Swedish grid from unit O1 since the start in 1972."

Oskarshamn 2 is a 638 MWe BWR which began operating in 1974.

In January, GE Hitachi Nuclear Energy (GEH) was awarded a three-year contract by Sweden's OKG AB to dismantle the reactor internals of both Oskarshamn 1 and 2. Under the contract, GEH will segment the reactor pressure vessel internals of both units. The work includes dismantling, cutting and packing the reactor internals for final disposal.

Researched and written
by World Nuclear News