This year’s last scheduled overhaul starts in Mochovce NPP

This year’s last scheduled overhaul starts in Mochovce NPP
The general overhaul of Mochovce 2 starts on 12 September, and Slovenské elektrárne in parallel continues in increasing the Unit’s efficiency by 7 %.

The essential activities of the outage, which should last less than four weeks, include works on technical water system, emergency reactor core cooling systems, electrical switchgear stations and non-destructive inspections of the reactor pressure vessel.

Repairs of control rod welds and replacement of control rod absorbers are scheduled, as well as inspections and repairs of heterogeneous welded joints of steam generators. The plant will also undergo repairs at one of six reactor coolant pumps and other works. The schedule also includes a containment tightness test.

Investment projects

In parallel, works on investment projects will be underway. The most important of these are the unit’s efficiency increase by 7 per cent, installation of an electric boiler and a long-term seismic resistance enhancement project, which will include some measures to increase the seismic resistance of switchboards and transformers, as well as severe accident management projects.

Once the overhaul works are over, Mochovce 2 will operate at half power – with only one turbine generator, until another turbine is replaced in November.

Preventive actions

In Slovakia, the September overhaul of Mochovce 2 is the last planned nuclear overhaul this year. However, at the same time it is this year’s first overhaul with unchanged, full scale scope of works, with presence of foreign contractors. They must comply to strict conditions set by the Chief Hygienist of the Slovak Republic and management of Slovenske elektrarne within the prevention measures in place against the spread of the new coronavirus.