The Watts Bar Nuclear Plant in Spring City, Tenn., was given a "white" safety finding by NRC inspectors in September for an equipment problem associated with the nuclear security division at the plant, not with the plant's operation.
Last summer, Sequoyah Nuclear Plant in Soddy-Daisy also received a white flag for having four unplanned shutdowns in less than a year. The plant has since had a fifth unplanned scram.
Last year, Browns Ferry Nuclear Plant near Athens, Ala., was placed under a red finding -- NRC's highest safety concern flag -- after NRC and TVA determined the plant may have operated for more than a year with a inoperable cooling system valve.
Source: NRC and TVA
Many of last year's nuclear "near misses" at U.S. reactors happened because plant owners -- and often their federal regulators -- tolerated known problems and failed to address them adequately, according to a report released Tuesday by the Union of Concerned Scientists.
"All NRC needs to do to protect the public is enforce its own requirements," said Dave Lochbaum, director of the group's Nuclear Safety Project and author of a report on nuclear plant safety billed as "Living on Borrowed Time."
"Willy nilly should be a cartoon character, not NRC [actions]," he said.
Although the report of nuclear "near misses" last year did not include any Tennessee Valley Authority reactors, the report's author still said TVA is "always a best bet for any year's report on near misses."
Lochbaum said Browns Ferry Unit 1 was reactivated after 22 years "and within years, it managed to mess itself up so badly that right now it's the worst plant in the country.
"There are 100 other reactors that had a headstart on that, but TVA managed to put Browns Ferry off the bench and into the game and very quickly to the bottom of the list within a short period of years," he said.
Ray Golden, communications manager for TVA, said TVA recognizes " there is still significant work that needs to be done to accomplish our goal of restoring Browns Ferry to top-performing status." Golden said TVA is working with regulators "to identify and address all issues and is committed to returning Browns Ferry to excellent operating performance."
Lochbaum said his "near misses" are events or problems that triggered special NRC inspections in 2011. The report gives NRC three "great catches" and 15 "near misses" last year.
Though Browns Ferry wasn't one of the three "great catches" he gave NRC for 2011, his report giveS a satisfactory nod to NRC for pushing TVA on a 2010 Brown's Ferry problem.
"That catch wasn't replicated this year," Lochbaum said.
NRC spokesman Joey Ledford said regulators are reviewing the Union of Concerned Scientists' report. But at first glance, Ledford said the study shows that regulators often detect potential problems long before they become safety hazards.
"The NRC's oversight program is designed to catch and correct problems well before they become anything approaching a 'near miss,'" he said.
But Lochbaum, a former TVA nuclear operator and a former NRC training instructor, said TVA's problems are largely in management.
"Like a full size bed with twin sheets, you can cover one side but not the other. [TVA] just can't seem to get all the plants at the right level. They'll fix whatever's going on at Brown's Ferry, but you see levels at Watts Bar and Sequoyah drop off. They can juggle one ball, but TVA seems to have trouble with three balls up in the air."
In the year since Brown's Ferry received a red rating from NRC prompting invasive inspections, both Watts Bar and Sequoyah have received NRC white findings.
Under NRC's color-coded inspection findings, white is least serious, then yellow, then red, the highest safety concern flag. Each increasing level concern calls for more NRC oversight. A plant operating with no safety problems is coded green.
All three TVA nuclear plants now have color-coded safety flags from NRC.
Lochbaum said the stakes are too high for the public and Congress not to push for improvements.
"For a mature [nuclear power] industry, 14 or 15 near misses a year is too many," he said. "We're relying too much on luck rather than on skill."