Inspections have identified three previously undetected cracks in the concrete shield building of the Davis-Besse nuclear power plant in Ohio, as well as some growth in cracks discovered in 2011. These are not considered to effect the plant’s safety.
Plant operator First Energy Nuclear Operating Company (Fenoc) discovered “tight cracks” within the reinforced concrete of the Davis-Besse reactor building in October 2011 during a major outage to replace the head of the reactor pressure vessel. The company notified the Nuclear Regulatory Commission (NRC), which determined the cracks did not present an “immediate safety issue” and the reactor returned to service two months later.
Examination of the inside of the building’s walls is currently being conducted using high-definition camera technology through a series of inspection ports. So far, inspections have been carried out through 43 of the shield building’s 82 inspection ports. The remaining examinations are expected to be completed over the next several weeks.
The current inspections have identified three “very tight, subsurface pre-existing cracks” in the building that were not visible with previous inspection technology. The inspections have also found that three other cracks, discovered in October 2011, “appear to have propagated a small amount.”
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