The tests performed at the Krško Nuclear Power Plant (NEK) over the past three years checked all vital safety systems at the plant. They were conducted by experts at NEK and its subcontractors, while results were verified by a group of international experts.

The verification process took several months and resulted in a list of additional checks and analysis as well as improvements which must be undertaken in the next five years, the administration said.

The second ten-year review at NEK coincided with the aftermath of the nuclear accident in Fukushima in 2011, as part of which the plant in Krško was also subject to a stress tests which focused on how the plant can respond to a major disaster.

According to the Nuclear Safety Administration, the results of the completed review have helped shape a programme of safety upgrades, which the plant has already begun to implement and which is expected to be fully realised in the coming years.

The next ten-year review is due to get under way just before the plant is to reach the end of its originally conceived life cycle and will have to be passed for NEK to have a shot at extending its operations beyond 2023.

The plant, which is jointly owned with Croatia, began commercial operation in 1983 and provides around a quarter of all electricity produced in Slovenia.