A unit at Bulgaria's nuclear power plant in Kozloduy was automatically shut down due to a short circuit, the Sofia news agency reported on Monday.

Unit 6 was frozen at 11 p.m. Sunday when the generator's safety system was activated over a short circuit in the control panel.

The NPP management said there had been no radiation leaks.

The unit is expected to restart on Wednesday. Other units are operating at capacity.

The Kozloduy NPP, located on the Danube near the border with Romania, currently operates two pressurized water reactors.

It previously operated four older reactors, but under a 1993 agreement between the European Commission and the Bulgarian government, they were retired.

In January 2009, Bulgaria requested permission to restart Unit 3 following a Russian-Ukrainian gas dispute that resulted in power shortages in the region.