New nuclear emergency preparedness requirements have come under fire nationally, with some saying the new guidelines weaken planning.
But local emergency and Tennessee Valley Authority officials say they will not scale down drills.
"Our annual drills with TVA for Sequoyah and Watts Bar will be as robust as ever, and the regulatory changes actually add to the different types of drills we'll be required to conduct every year, such as hostile action," said Dean Flener, spokesman for the Tennessee Emergency Management Agency.
The new requirements represent the first change in more than 30 years, but they were finalized with no fanfare and published in the Federal Register just before Christmas. They require fewer exercises for major accidents and recommend that exercises call for fewer people -- those within two miles of the plant -- to be evacuated right away.
The guidelines still call for one full exercise for a 10-mile evacuation every two years, but they lessened the frequency for the 50-mile planning exercises from every six years to every eight years.
They also eliminate a mandate that local responders always run practice exercises that assume a radiation release.
The changes -- in the works for four years -- appear to ignore a sobering lesson from last year's triple meltdowns at Fukushima Dai-ichi Nuclear Plant in Japan.
The radiation can spread much farther than 10 miles in some circumstances.
In Japan, officials told some towns beyond 12 miles to evacuate, and soil and crops were contaminated for scores of miles around the plant. Health authorities in Tokyo, 140 miles away, advised families not to give children the local water, which was contaminated by fallout to twice the government limit for infants.
The U.S. government recommended that Americans stay at least 50 miles from the Japanese plant, and federal officials said the same kind of action could be taken domestically in a similar accident. Yet advance planning for U.S. evacuations -- even in the new rules -- is restricted to 10 miles.
"We didn't think a 10-mile zone was sufficient before Fukushima, and now we know it's not," said Ed Lyman, senior scientist and nuclear security expert for the Union of Concerned Scientists. "There needs to be a follow-up rule as soon as possible."
Officials with the Nuclear Regulatory Commission and the Federal Emergency Management Agency defend their new guidelines, describing them as little more than new rotations of required drills in order to allow more varied drills and planning.
The new rules include one new exercise.
More than a decade after the 9/11 terrorist attacks, state and community police now will take part in exercises that prepare for a possible assault on their local plant.
"The new rule requires the plants ... to insert new scenarios that, among other things, adds a level of uncertainty to the exercises," according to an NRC blog published Friday.
Jim Hopson, a TVA nuclear communications consultant, said the new rules give nuclear operators a broader variety of scenarios to test, and he thinks that's good.
Fukushima showed nuclear operators and emergency responders that yesterday's assumptions should be challenged, he said, adding that new scenarios for the drills can help with that.
"The number of drills we're having are just as intense than they were before [the new guidelines]," he said. "This is more a change in the scenario rotation. I think it does enhance [drill experience] because it gives us a broader base. We're not backing off our emergency preparedness planning."
The drills -- conducted with local emergency planners -- are full-blown tests, with FEMA evaluation. The tests grade not just the nuclear reactors, but also the emergency responders.
Last October, Watts Bar Nuclear Plant was the site of one of these tests.
About 1,000 TVA workers, along with state and local emergency responders in McMinn, Meigs and Rhea counties, took part in the mock emergency preparedness exercise.
The scenario was a pretend explosion in the diesel area of Watts Bar Nuclear Plant, then a steam vent began leaking radiation, leading to the fictional evacuation of everyone within a 10-mile radius to the east, south and west of the plant.
The drills are manpower intensive, but Hopson said he does not think cost had anything to do with lessening the frequency of the biggest drills.
"I think it's to ensure we can respond as we need to in wider variety [of what ifs,]" he said.
Lyman said a bright spot in the new rules is that nuclear operators now are required to re-evaluate their 10-mile evacuation plans in light of fast-growing populations around the plants.
Hamilton County Emergency Services Chief Bill Tittle said last week he doesn't think it is a good idea to lessen in any way preparedness for nuclear problems.
So far, he said, he's not seeing any reductions.
"We met for a couple of hours [last week] planning the Sequoyah exercise for later this year," he said.
"We have not lessened in any way our preparation with any of the above this year. We're doing this as we always do -- aggressively and consistently."
The Associated Press contributed to this story.