The European Commission on Wednesday evening through a special emergency alarm system, the European Community Urgent Radiological Information Exchange, issued an EU-wide warning to all 27 member states, after cooling water had leaked from a power plant in Krsko, Slovenia. Officials said the coolant had leaked during a routine check, and the plant, which began production for the first time in 1981, was subsequently shut down. Such an alarm is very unusual, observers say.
Slovenia shares land borders with Croatia, Italy, Austria and Hungary, and thus, a serious nuclear accident would also affect large areas of Europe. On Thursday, several European media outlets had made the Slovenian nuclear accident their main news story.
Yet on Thursday, politicians were eager to contain the media disaster.
Slovenian nuclear officials vowed that no radioactivity had been released, adding there was absolutely no danger for humans or nature.
Janez Podobnik, Slovenia's environment minister, said Thursday in Luxembourg that the plant may soon go online again, as only a "very small" repair was necessary. "There was no accident, only a minor water leak. The situation is completely under control," he said, according to Spiegel Online.
Environmental organizations like Greenpeace, however, have warned Slovenia not to give the all-clear too quickly.
"A very short time has passed since the incident," Thomas Breuer, a nuclear expert at Greenpeace, told German news channel N24. One should keep in mind that setting off such an alarm "has never happened before in Europe."
The leakage of coolant, he added, was "basically the worst thing that can happen in a nuclear power plant."
If not managed effectively, the results of a loss of coolant accident, also called LOCA, could be catastrophic to a reactor, mainly because of the massive amount of heat generated. In an unlikely -- yet not impossible -- worse-case scenario, it could lead to a core meltdown.
In neighboring Croatia, officials are worried; the relatively old Krsko reactor is only roughly 30 miles from Zagreb, Croatia's capital, and thus a constant source of concern for officials there, who have complained that they weren't informed properly or on time.
Slovenia's government, meanwhile, has admitted to mistakes in the process of reporting the incident. According to Slovenian media reports, officials had used a wrong form and initially reported the incident as an exercise of the radiation protection agency -- a mishap that was later corrected.
It is not the first time that the Krsko reactor, which generates on average about 5,277 GWh of electricity a year, has had problems: Almost five years ago it was shut down after circuit issues; the incident resulted in energy shortages for Slovenia, but also for Croatia, which shares ownership of the plant because of its construction in times when both countries still belonged to former Yugoslavia. It runs on a Westinghouse Pressurized Light Water Reactor with a thermal power of 2,000 MW, and has a planned retirement date of Jan. 14, 2023, and the entire deconstruction process would take 12 years, officials have said.
In Austria, opponents of nuclear energy have long lobbied to shut the plant down much earlier, and the latest incident may hand them some fresh arguments.