15.10.2009 Lauri Myllyvirta
Finnish nuclear watchdog STUK has ordered welding of the reactor cooling system to a halt at Olkiluoto 3 construction site, Finland. A welder had failed to consult or comply with welding specifications and consequently too high electric current was used in welding. Substandard practice had passed three layers of inspections: subcontractor, French Areva and Finnish investor TVO. The experiences from Olkiluoto show that as far as nuclear is concerned, safety and economics don’t mix.
“Greenpeace exposed already a year ago, that welding without required tests and paperwork was a common practice in welding of Olkiluoto 3 containment building. STUK failed to crack down on rampant violations at the time, claiming that quality of welds was sufficient at the time. Greenpeace warned already back then that neglect of quality requirements would affect even more critical phases of work,” Greenpeace energy campaigner Lauri Myllyvirta reminds.
The cooling system is the most central and vulnerable part of a nuclear reactor, because its failure can lead to a full-scale nuclear accident. Components of the cooling system are not replaced during the entire lifetime of the reactor. There have also been problems with other parts of the cooling system. During welding of the largest pipes of the system, the ones connected directly to the reactor core, cracks were observed aroubd the weld seams. The cause can be either defective material or unsuitable welding method.
“The unrealistic price and timetable of Olkiluoto 3 project are leading to more and more violations of quality requirements. The combined impacts of all the problems is impossible to assess when there are severe flaws in both the design and the construction of the reactor. Proposed new reactor projects are based on equally unrealistic assumptions, so the problems would be bound to reoccur,” Myllyvirta said.
Lauri Myllyvirta, energy campaigner: +358 50 3625 981