Bulgaria’s sole nuclear power plant (NPP) Kozloduy said that it has shut down its 1,000 MW Unit 5 on Wednesday for planned annual maintenance. The works are expected to be completed by mid-June, the power plant operator said in a press release on Wednesday.

During the planned outage, the reactor will be reloaded with fresh nuclear fuel. In addition, upgrades will be carried out in relation to the project for increasing the unit’s thermal capacity to 104%, according to Seenews. Kozloduy’s other 1,000 MW unit, Unit 6, is currently operating at full capacity.

Kozloduy NPP has two operational units – Units 5 and 6 – of 1,000 MW each. The plant’s four other units, of 440 MW each, were closed down to address nuclear safety concerns of the European Union prior to Bulgaria’s accession to the bloc in 2007.