KIEV, Oct. 24 - Zaporizhia nuclear power plant, Ukraine’s largest, unexpectedly shut down its 1,000-MW reactor No. 2 after discovering a leak in a pipeline of independent contour of the main circulation pump, Energoatom reported Monday.

The shutdown comes three weeks after the reactor’s life had been extended for 10 years following a 235-day upgrade.

“Radiation at Zaporozhe nuclear power plant sites does not exceed normal levels,” Energoatom said in a statement, adding that the reactor should be back online on October 30.