Photo taken by Calvert Cliffs nuclear power plant workersThe powerful tornadoes that ravaged central Nebraska a few days ago, with film footage aired by BBC, were fortunately over 100 miles to the west of the flooded Fort Calhoun nuclear power plant site on the Missouri River north of Omaha. The Minneapolis Star Tribune reported that one tornado was a powerful EF3, with winds as high as 165 miles per hour. It, along with a number of less powerful tornadoes, took down power lines in several places across Nebraska. As KLKN TV reported, 3,500 Nebraskan households lost electricity due to the downed power lines. If the Ft. Calhoun and Fukushima-twin Cooper atomic reactors in eastern Nebraska had similarly lost off-site power, they would then have been thrown onto emergency diesel generators -- themselves put at risk by the historic flood waters on the Missouri.
As shown by the Fukushima nuclear catastrophe in Japan, "station blackout" at atomic reactors and high-level radioactive waste storage pools can cause catastrophic radioactivity releases, due to loss of cooling water circulation. And most U.S. reactors have less back up battery power -- the last line of defense -- than did the Fukushima Daiichi nuclear power plant -- 4 hours instead of 8. Tornadoes have come precariously close to causing severe damage, or even overheating of reactor cores and radioactive waste storage pools, at U.S. nuclear power plants in the past. In 1998, the Davis-Besse atomic reactor near Toledo came close to complete failure of its emergency diesel generators after the grid was lost due to a tornado passing between the reactor containment building and the cooling tower on site. Last decade, a powerful tornado that went on to destroy the town of La Plata, Maryland came within a mile or two of the Calvert Cliffs nuclear power plant on the Chesapeake Bay (see photo at left). And in June 2010, a tornado damaged the Fermi 2 nuclear power plant in Michigan; fortunately, the emergency diesels worked -- they had been inoperable from 1986 to 2006.