Oskarshamn 2 outage extended to year-end

13 March 2015

The safety modernization of unit 2 of Sweden's Oskarshamn nuclear power plant is now expected to be completed by the end of 2015, plant operator OKG announced today. The work began in June 2013.

Oskarshamn 2 (Image: OKG)

OKG said the reason for the further delay in completion of the project is "greater precision in the estimate of the time required for the remaining works and additional analytical works."

In March 2014, OKG announced it had decided to postpone the uprate work to allow it to focus on the ongoing safety work. The company then said last June it intends to implement the power increase during 2017, two years later than originally planned.

OKG now says that, as the modernization of safety systems at Oskarshamn 2 has progressed, "there is greater awareness of how long the remaining measures are expected to take." The company estimates that the unit will resume operations in nine months. It noted, "This is clearly a miscalculation compared with the original time estimate for these works."

Safety modernization work being carried out at the 638 MWe boiling water reactor (BWR) is the penultimate stage of a major SEK 8 billion ($920 million) modernization program which includes a planned 185 MWe power uprate at the plant. The current phase of work involving electricity and control systems has been described by OKG as the most extensive, and most important, in the whole program but has encountered delays thanks to the 'unique and sophisticated challenge' of recabling the facility.

Once the project is completed, some 800 tonnes of new components will have been installed in the plant and more than 100 kilometres of cable will have been laid. A large volume of this cable has now been laid, while a new control room and simulator have been installed. "The focus from now on will primarily be on commissioning, testing and analysis," OKG said.

OKG managing director Johan Svenningsson said, "Neither the underestimate of the complexity of the ongoing works nor the additional works mean that there is less confidence that it will be possible to achieve the project's ultimate objective." He added, "We now have the very extensive installation work behind us and are moving into the final phase of the project. This is where we will primarily be conducting the comprehensive trials and tests to verify that the plant satisfies the requirements for a modernized nuclear power plant."

Svenningsson noted, "In projects such as this, there are always very strict demand on safety and quality in implementation, and time must be allowed for this. When we resume operation at the plant, according to the revised schedule of 20 December, we will have moved from a level that was already high to an exceptionally high level in terms of the plant's safety."

Researched and written
by World Nuclear News