The Krško plant has returned to service after having successfully completed maintenance and refuelling outage

The Krško Nuclear Power Plant has been reconnected to the power grid on Wednesday, 5 May 2021. After tests at a low-power, we are gradually increasing the plant power. During this regular outage, which started on 1 April, competent and responsible workers have completed more than 40.000 activities without delay and within the planned scope regardless of demanding epidemiological circumstances which made the delivery of goods and services considerably harder.

We have replaced 56 out of 121 fuel elements in the reactor core with fresh ones to ensure energy source for the plant’s operation until the new outage which is due to begin in autumn 2022. We have completed the planned maintenance works, checked the material integrity of the equipment and structures, and carried out hundreds of surveillance tests which proved suitable performance of the plant systems and components. Among 13 major upgrades, most of them were part of the Safety Upgrade Program. Tested and connected to the plant systems were among others: new independent Alternative Residual Heat Removal System (ARHR) for cooling the reactor core and the containment, Alternative Safety Injection (ASI) Systems, Alternative Auxiliary Feedwater System (AAF), and power supply for a new Bunkered Building (BB).

The Slovenian Nuclear Safety Administration conducted inspections of the quality of the outage works together with authorised institutions. Protective and restrictive measures taken against the coronavirus epidemic increased the complexity of the outage works. Although more than 1500 workers were daily onsite simultaneously, we are happy to have succeeded in completing the planned extensive and demanding works in full and to ensure safe working conditions. Collaboration with the regulatory bodies, expert organisations, contractors, and health care institutions was on a high level.