Protective sleeves on the control rods at one of the reactors in Bulgaria's sole nuclear plant need to be replaced as a safety precaution, the plant said in a statement Thursday.
The Kozloduy nuclear plant said sleeves on the 61 control rods in the 1,000 Megawatt reactor number six had to be replaced with more modern protective material.
An inspection a year ago found cracks in half of the control rod sleeves in reactor number six and they were replaced at the time.
The plant did not say Thursday if new cracks had been found since then.
A similar problem arose last year with reactor number five, where 37 of 61 control rod sleeves were found to have faults, with management deciding to replace all of them at that time.
In 2006, cracks in the protective sleeves at reactor number five appeared while it was in operation. That incident was rated level two out of seven on the International Nuclear and Radiological Event Scale (INES).
Kozloduy has four other small reactors but these were closed between 2002 and 2006 as a result of European Union pressure over their safety.
