The slow flood

摘要

Unseasonably heavy snows in the Great Plains, heavy rainfall upriver and a late snowpack melt combined to flood the Missouri river from late May through September 2011, a flood which utility Omaha Public Power District calls the longest-lasting flooding of any US nuclear power plant. That floodwater had a disastrous effect on the site of Fort Calhoun, which is located on the bank of the Missouri near Blair, Nebraska (north of Omaha), at an elevation of about 4.5 m (15 feet) higher than the mean river level. The station, a Combustion Engineering 500MWe PWR, draws river water to cool the turbine condenser in a once-through system.