The fifth reactor is scheduled to begin operation 4 month later than planned – on May 30, 2005, as the defective parts in the reactor lid should be changed, ITAR-TASS reported. The reason behind the delay was the discovery of cracks in the welded seams of the reactor lid of the fifth block. Experts hold that the cracks had appeared due to a production defect and aggressive environment where the faulty parts were operating and claim all the other VVER-1000 reactors have a different safer technology.

On February 4, the head Rosenergoatom concern had to visit the plant to look personally at the ongoing repairs.

The 30 years lifetime of the fifth block expires in 2010, but Russian experts say that it may be prolonged for another 20-year period.