SODDY-DAISY (AP) — The Tennessee Valley Authority is showing more jitters about Japan's nuclear emergency than some residents who live in the same neighborhood with reactors operated by the nation's largest public utility.

TVA called off a long-scheduled media tour Wednesday at its Watts Bar Nuclear Plant that is the site of the nation's only nuclear reactor under construction.

The utility said in a statement that the tour at the plant between Knoxville and Chattanooga on the Tennessee River was indefinitely postponed "while the industry focuses on events in Japan."

Japan is facing a crisis from radiation from damage at a nuclear plant damaged after a 9.0 magnitude earthquake caused a tsunami.

"TVA and the nuclear industry are in full scale damage mode," said Stephen Smith, director of the Southern Alliance for Clean Energy in Knoxville. "They are watching millions and millions of public relation dollars go up in smoke. There are very legitimate questions."

Ray Golden, a spokesman for TVA's nuclear operation, said the plants in Tennessee are designed to withstand a 5.8 magnitude earthquake from the Giles Virginia Fault Zone and the Browns Ferry plant near Athens, Ala., is designed for a 6.0 earthquake from the New Madrid Fault Zone.

TVA chief operating officer Bill McCollum said in a video posted on TVA's website that the utility's six reactors are "designed, built and operated to be safe."

He said TVA, which is also considering up to four more reactors, is monitoring events in Japan and "there will be lessons learned."

"It's far too early to assess the total impact of this," McCollum said.

The TVA board at a meeting in April is expected to discuss committing funds to future nuclear projects. Nuclear plants generate about 20 percent of TVA's power supply and with the utility working to reduce dependence on coal, McCollum said the percentage of nuclear could increase to 30 percent over the next decade.

Retiree Carolyn McMahen from her backyard in Soddy-Daisy can see TVA's Sequoyah Nuclear Plant less than a mile away and said she has confidence in TVA.

"We are just trusting," she said Tuesday. She said TVA provides emergency preparedness materials and a test siren blares the first Wednesday of each month.

"We have friends who work there and we have asked them about it," said McMahen, 72. "They kind of make me feel reassured, too."

McMahen said "you can't live any certain place and not expect anything to happen. There are floods around here, too."

National Regulatory Commission region spokesman Roger Hannah said all nuclear plants are "designed to withstand the maximum credible earthquake for that area, based on historical data" and on seismic activity.

During a series of strong quakes along the New Madrid Fault in 1811 and 1812, one reportedly was so powerful that it caused the Mississippi River to flow backward for a time and formed Reelfoot Lake, the largest lake in Tennessee. Though no earthquake measuring instruments existed, estimates put it at magnitude 8.0. The Richter scale that measures earthquakes was developed in 1935.

With about 80 recorded tremors a year, East Tennessee is among the most active regions in the East. Those tremors are far smaller than a magnitude 4.9 quake in April 2003 that shook people from their beds in northeast Alabama. Japan's initial earthquake was measured at 9.0.

TVA's inland plants also are not subject to the kind of tsunami that obliterated some of Japan's northeastern coast.

"Our plants while situated on the Tennessee River, they are not on the Pacific Ocean," Golden said.

Smith said Wednesday that TVA and other electrical utilities may have underestimated the earthquake risk.

"Clearly that happened in Japan," he said.

Golden and Smith said the General Electric reactors at TVA's Browns Ferry Nuclear Plant are similar to the reactors in Japan. Smith said his alliance has previously challenged some operating features of the reactors related to fuel rods.

He said regulators should go slowly in issuing any new nuclear plant license permits and government officials should stop issuing loans for the projects.

"I don't want to be overly inflammatory," Smith said. "What is in the long term best interest of public safety?"

He said nuclear plants are "not inherently unsafe but they are inherently unforgiving."