Slovenia's sole nuclear power station will generate roughly 10% less electricity this year than initially planned as a result of a six-week long shutdown in the autumn to repair a tiny pipe leakage in the primary system.

The Krško plant was shut down as a precaution on 6 October after a leakage was detected within the containment building. Following repairs, it was reconnected to the grid on 17 November.

Due to the unscheduled shutdown, the projected output this year has been downgraded to 5.33 terawatt-hours (TWh), 11% less than the original plan, the plant's CEO Gorazd Pfeifer told reporters on 19 December.

He said the direct cost of the unscheduled repairs was €13.8 million. He assessed the operation had been completed in an "exceptionally short time" and to the highest standards.

The damaged pipeline was repaired by Westinghouse, the US company that supplied the original technology in the 1970-80s, when the plant was built.

Data from the plant's website shows the power plant generated 5.37 TWh of electricity this year by 2pm on 19 December.

Last year, when the plant was shut down for 38 days for scheduled maintenance, it generated 5.31 TWh electricity, according to the annual report for 2022.

In the first three quarters of the year, the planned output was surpassed by 42 gigawatt hours.

Next year, the plant is to generate 5.45 TWh of electricity. Employing about 650 staff, it is already preparing for the next scheduled maintenance, beginning on 1 April 2024.

The fuel for the next cycle has already arrived at the plant, Pfeifer said, adding they continue with continuous upgrades of their equipment and systems.

NEK, which is co-owned by Slovenia and Croatia, was launched in 1983. In January it received an environmental permit to expand its lifespan by 20 years until 2043.