Start-up of Europe’s first EPR nuclear power plant, the Olkiluoto 3 under construction in Finland, has been postponed beyond June 2012 because civil construction is taking longer than was previously estimated, according plant owner Teollisuuden Voima Oyj (TVO). Finland’s nuclear regulatory agency has, meanwhile, called attention to “deficiencies” in the welding of the plant’s cooling system, potentially causing further delays.

The Finnish utility said last week that the plant’s supplier, an AREVA-Siemens Energy consortium, is responsible for the current schedule, and that it has requested a re-analysis of the anticipated start-up date.

Work on the long-awaited nuclear power project began in 2005, and the plant was originally due to come online in 2009, but the project has been consistently plagued with faulty materials and planning problems. AREVA in September revealed that the total cost of the flagship third-generation reactor had risen to some €5.3 billion—up from the originally estimated cost of €3 billion. Costs could go up even more because of timeline uncertainties.

The project’s 4,100-person workforce last month erected the 200–metric ton dome section—a significant milestone. Erection of main turbine components has also been completed, and civil construction works and erection works at the reactor building continue. TVO said the reactor building now stands in its final shape and height at almost 60 meters.

Project Director Jouni Silvennoinen said in a release last week that accumulating delays of civil construction works would impact the installation and erection works. ”Additionally, there continues to be delay in the development of the [instrumentation and control] system and this may become critical for the plant time schedule,” he said.

Meanwhile, Finland’s Radiation and Nuclear Safety Authority Finland (STUK) last week said it had noticed that “instructions had not been observed in the welding of pipes and the supervision of welding,” and that inspectors noticed deficiencies in the welding of the pipes in the plant’s cooling system.

“Among the deficiencies observed were that one welder did not have the welding instructions at his disposal, neither was he familiar with the welding requirements, as a result of which an excessive amount of power was being used in the welding,” STUK said. “Other deviations noticed concerned the use of shielding gas necessary for welding and the shape of the contact surfaces to be welded.”

STUK said that TVO would be required to explain why instructions were not observed and why the supervision carried out by the subcontractor, plant supplier, and TVO did not result in these deficiencies being observed. “Furthermore, TVO must explain the significance of the deficiencies observed from a point of view of weld quality,” it said. “The report must suggest remedial measures through which welding work and its supervision can be made to comply with requirements. The subcontractor is not allowed to continue the welding work until the reports have been approved.”

The regulatory agency said it had previously drawn attention to welding quality and its supervision in the welding of the steel lining of the containment building, among others. “The matter will continue to require special attention from TVO as the volume of pipe installation work increases in the near future.”

Sources: TVO, AREVA, STUK, POWERnews