Davis-Besse's cracked shield building is safe the NRC has concluded
Federal regulators have accepted FirstEnergy Corp.'s analysis that the Great Blizzard of 1978 damaged the massive building housing the Davis-Besse nuclear reactor - but not enough to keep the plant idle. In a report issued amid a chorus of critics Thursday, the Nuclear Regulatory Commission agreed with the company's analysis that the storm of Jan. 25-27, 1978, which began as rain, drove moisture deep into bare concrete walls of the building, where it froze within a day or two.
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The report agrees with the company's conclusions that the myriad cracks in the building's 2.5-foot reinforced concrete walls have not weakened it to the point that it cannot function - though it is weaker than it was designed to be and will need regular inspections, said Charles Casto, the head of the NRC's Midwest division. "The question is does the building maintain the strength required. Our conclusion is that it does meet the strength requirements for safety. We have independently verified that the building is safe," he said.
Most of the cracking in the concrete occurred along heavy steel reinforcing bars buried inside the wall. When the company calculated the strength of the damaged wall, it conservatively left out the strength of the steel bars themselves, said FirstEnergy spokesman Todd Schneider. Those calculations showed that even then the building still would have a reserve safety margin.
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U.S. Rep. Dennis Kucinich and an anti-nuclear group, Beyond Nuclear, separately have questioned the storm thesis, pointing out that if that were true, the cracks would all be on the side of the southwest side of the building where the storm wind pushed the hardest. The report notes that there are more cracks on that side but that cracking has been found elsewhere as well. Casto, of the NRC, said because of its shape the cylindrical building would be uniformly soaked, in a storm of that magnitude.
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