Brownville , Nebraska ( CNN ) -- A top manager at one of Nebraska 's two nuclear power plants says he 's `` 100 percent confident '' the facility 's countermeasures will keep the overflowing Missouri River from damaging critical gear and causing a hazard to the public . The Cooper Nuclear Power Station , about 80 miles south of Omaha , is still in operation and several feet above the swollen waterway . Nuclear Regulatory Commission Chairman Gregory Jaczko toured the plant Monday , along with a plant north of Omaha that is already surrounded by floodwaters . `` I am not going to predict what is going to happen with the water level , '' Jaczko said . `` Our job is to make sure the licensee does their job to make sure the plant stays safe . Right now , it appears they are taking proactive steps to do that . '' The NRC says both Cooper and the Fort Calhoun plant , about 20 miles north of Omaha , have taken precautions against this summer 's flooding . And Brian Hasselbring , a reactor operator at Cooper , said even high water wo n't cause a radiation leak . `` I am 100 percent confident that we are not going to have an issue here , '' Hasselbring said . `` If river levels continue to rise , we will follow our procedures , we will shut down the plant , do whatever is required to maintain our safety . '' At Fort Calhoun , as much as two feet of water has forced plant workers to navigate a catwalk from the parking lot , and a water-filled berm that surrounded the reactor containment structure and auxiliary buildings was punctured by a worker early Sunday . A representative of the manufacturer is at the plant helping assess whether the berm can be repaired , the plant 's owner , the Omaha Public Power District , said . But the plant has been shut down for refueling since April , and authorities have put floodgates , sandbags and other barriers in place to help protect the facility . Despite the flooding , Fort Calhoun is designed to withstand water up to 1,014 feet above mean sea level , according to the Omaha Public Power District . The river is not expected to exceed 1,008 feet , the OPPD said . Plant managers also have brought in additional diesel fuel for generators should the site lose electricity . Workers switched to those generators briefly to keep the plant 's spent fuel cool after water came too close to electrical transformers , but the plant was again drawing power from the electrical grid , utility spokesman Jeff Hanson said Monday . `` The plant is designed , when they get to these higher flood levels , to use their diesel generators when necessary , '' Jaczko said . It was catastrophic flooding from Japan 's March 11 tsunami that knocked out cooling systems at the Fukushima Daiichi nuclear power plant , resulting in three reactors melting down and producing the worst nuclear disaster since Chernobyl . This year 's Midwestern flooding has also led to a spate of rumors about the Fort Calhoun plant that OPPD and the NRC have been trying to knock down . The utility has set up a `` flood rumor control '' page to reassure the public that there has been no release of radioactivity from the plant . An electrical fire June 7 did knock out cooling to its spent fuel storage pool for about 90 minutes , but the coolant water did not reach a boiling point before backup pumps went into service , it has said . Heavy rainfall in Montana and North Dakota , combined with melting snow from the Rocky Mountains , have sent the Missouri surging downstream this summer . The river washed over and punched through levees in northwestern Missouri , spurring authorities to urge about 250 nearby residents to leave their homes . The 6 to 12 inches of rainfall in the upper Missouri basin in the past few weeks is nearly a normal year 's worth , and runoff from the mountain snowpack is 140 % of normal , according to forecasters . The Missouri River is forecast to remain at record or near-record levels from south of Omaha all the way to Atchison , Kansas , into next week . The flooding is affecting communities in Nebraska , Kansas and Missouri . CNN 's Patrick Oppmann and Ed Payne contributed to this report .
NEW : Nuclear regulator tours plants along the swollen Missouri River . Critical gear has been protected at both plants , officials say . Floodwaters have encroached on the idled Fort Calhoun plant . The still-operating Cooper plant remains several feet above the river .