Modernisation of the Oskarshamn 2 boiling water reactor in Sweden is expected to be completed before the end of 2015, OKG has said.

Originally the project, which began in June 2013, was scheduled for completion in 2014. But OKG said that there was a "clearly a miscalculation" in the original estimate.It announced that the project would be delayed last summer, but did not reveal a schedule.

The ultimate objective of the three-phase project is to achieve a power increase from 660MW to 840MW, and to implement safety upgrades at the unit, which will support plant operation for an additional 20 years.

The modernisation process has so far involved laying a high volume of cabling in the existing plant and installing a new control room and a new simulator. In all OKG says the project will entail laying more than 1100km of cables and completing approximately 100,000 electrical connections and 20,000 welds.

"We now have the very extensive installation work behind us and are moving into the final phase of the project," said Johan Svenningsson, managing director, OKG. "This is where we will primarily be conducting the comprehensive trials and tests to verify that the plant satisfies the requirements for a modernised nuclear power plant."

OKG estimated in March that an additional nine months of work remains before the reactor can resume production. Earlier this year the Swedish Radiation Safety Authority approved OKG's ongoing safety reports, which OKG said marks 'a major step' towards being able to start trial operation of the plant once the works have been completed.

Operation is set to resume at Oskarshamn 2 on 20 December 2015, according to the revised schedule.

Photo: Oskarshamn 2 (Credit:OKG)