Nuclear alerts in Bulgaria, Russia

Cracks were detected in control rods at Bulgaria’s sole nuclear power plant Thursday. With the world on edge over nuclear safety following the accident at Japan’s Fukushima Daiichi power plant, the Bulgarian operator insisted that no radioactive material was released.

Reuters/Jack Naegelen

The cracks were found during regular maintenance checks and a refuelling operation at Kozloduy nuclear plant, in the north-west of the country.

Thirty-seven out of 61 control rods at reactor number five were found to contain defects. All of the reactor rods will be replaced following the incident.

The planned replacement will not delay the preparation to move the reactor back on to Bulgaria’s national power grid next month, the operator added.

Earlier this year cracks in 31 control rods were found in reactor number six at Kozloduy. All the rods were replaced and the chief executive of the plant was sacked.

Last week engineers detected increased radiation within the confines of reactor five, but conditions remained normal outside the block.

Four of Kozloduy’s six reactors were shut down in order for Bulgaria to enter the European Union in 2007.

A Russian atom-powered icebreaker was forced to turn back to port after it developed a nuclear leak Thursday.

A fleet official said an “insignificant increase in activity” had been reported on board the Taimyr icebreaker.

The ship in the Kara Sea, part of the Arctic Ocean, was attempting to return to the port of Murmansk on Thursday afternoon.

Officials were keen to downplay the risk, stating it ranked zero on the seven-point International Nuclear and Radiological Event Scale, which constitutes “no safety significance”.

But even a small leak could endanger the lives of the ship’s crew or potentially develop into a more serious incident, military analyst Pavel Felgenhauer told the AFP news agency.