"The plant has not suffered any damage, all tested systems are functioning properly," the plant operator said in a statement after carrying out a systematic inspection and testing of the plant's equipment.
Start-up and testing procedures for the reactor and plant's systems will take place until the expected time of restart.
The power plant is expected to reach 50% capacity at night and full load on Thursday, it said.
Krsko NPP, located in Slovenia near the border with Croatia, generates some 40% of Slovenia's electricity output. It operates a Westinghouse pressurised light water reactor of 2,000 MW thermal power capacity, which generates over five billion kWh of electricity per year.