A nuclear power plant in Slovenia that was shut down because of a water leak is expected to stay closed until early next week.
The incident at the country’s only nuclear reactor set off an alert system in which all 27 EU nations are warned about a possible danger.
Slovenia later said no radiation entered the atmosphere.
Environmental campaigners went to the plant to carry out radiation readings.
One of them, Daniel Meijers, from the group Global 2000, said: “We [went here] at the entrance and at the back of the nuclear power plant, where the water exhaust [is] and we did not find any increased radiation level that was higher than the background noise. So that was actually good.”
Slovenia has apologised for a mistake in its initial warning, by referring to a test and not a real incident. But it maintains there was no real danger.
The Slovenian Environment Minister, Janez Podobnik, said: “There was no accident, just a minor water leakage. The situation is fully under control and there is no impact on the environment or on people.”
While debate rages about the safety of nuclear plants in Europe, Italy says it plans to restart its nuclear energy programme and the UK government has also approved the building of new plants.