NEK, which had a workforce of 617, exceeded the production target by 30 gigawatt hours in a year during which it underwent scheduled maintenance and refuelling.

It said its operations were reliable and stable and in line with all security and environmental standards.

Along with the extensive month-long scheduled maintenance works, the plant received a number of upgrades designed to boost the safety and reliability of its operations.

In the autumn, NEK also underwent an inspection by the World Association of Nuclear Operators, which will be followed this year by an IAEA EPREV mission that will check the plant's preparedness for the case of a nuclear accident at the local and state levels.

The plant, where no maintenance is scheduled in 2017, expects to supply the national power grid with 5,900 gigawatt hours of electricity this year and will continue pursuing cost effectiveness to remain competitive.

The Krško nuclear power power plant has been in operation since 1981 and its output is shared with Croatia.

In 2014, the Nuclear Safety Administration cleared it to operate for another 10 years while its owners, the Slovenian Gen energija and Croatian utility HEP, decided to extend its useful life until 2043.