By Challen Stephens and Brian Lawson

ATHENS, Alabama -- Browns Ferry Nuclear Plant has not improved. Not enough. Not yet.

Despite years of preparation and improvements, Alabama's largest nuclear plant remains in "red" status, one step from a forced federal shutdown.

It's the only plant in the nation under the serious "red" warning, and according to the U.S. Nuclear Regulatory Commission, only the fourth nuclear site in the last 13 years to earn a "red" finding.

Yet regulators spent much of Thursday talking about how much has improved since 2010, when a blocked emergency cooling line led to the warning label and intense federal inspections.

During a public presentation of the recent NRC inspection of Browns Ferry, federal regulators announced the "facility is being operated safely." They said they found evidence of an improved attitude among workers and improved equipment reliability at the plant.

But the NRC, which dispatched a 23-member inspection team to the plant in May, also found 300 "issues" of violations of TVA standards or federal requirements. The full published findings will not be available for another four to six weeks.

Gene Guthrie, head of the NRC inspection team, said that NRC had concerns about "recurring and long-standing" issues related to safety culture and equipment violations.

Nuclear Regulatory Commission findings during Browns Ferry inspection:

• Unit 1 reactor remains in Column 4, one level short of shutdown, which stemmed from 2011 red finding. Plant remains under increased federal oversight as TVA continues to work on improvements.

• Plant is being operated safely. Overall performance has improved since 2011 inspections.

• TVA has embarked on more than 1,300 corrective actions.

• Inspectors in May visit observed more than 300 occasions where workers were not meeting TVA standards or were violating regulatory requirements.

• Plant is showing higher regard for safety culture, but safety culture problems remain.

• TVA still has to make changes to its corrective action plan and follow through with NRC requested corrections to improve regulatory standing.

In the end, the NRC left Browns Ferry where it's been for the last two years, under a "red" warning and due for further intensive federal inspections. NRC said it is still waiting to see how policies and practices adopted recently will affect future performance at the plant.

For example, Guthrie said, "TVA needs to continue to improve its standards in worker performance." He also mentioned a need for better ways to cut chances for human error.

Guthrie said the plant will continue to operate in the "red" status, also known as operating in Column 4, while NRC continues to conduct follow-up inspections and monitor improvement plans. TVA's response to those inspections will determine its future regulatory status.

"This is a necessary wicket that we have to get through," said Chip Pardee, TVA's chief generation officer. He said the plant is improving, but the past obstacles were no secret. As for the NRC's findings: "It's what we expected," said Pardee.

Victor McRee of the NRC said that in 13 years only four nuclear sites have received a red finding. Also, at least plants over previous decades have been shut down for safety concerns, he said.

The NRC briefing was laden with regulatory jargon about cornerstones, cross-cutting and agency action matrix. After two hours of presentation on the campus of Calhoun Community College, one member of about 60 people in the audience asked: "You really haven't lifted the red finding yet?"

"To answer that question once again," began McRee, assuring the audience that the red finding remains and there is no certain date on a future decision on the status of Browns Ferry.

TVA picked the date for the inspection, the NRC noted, announcing in February that the plant was ready.

Browns Ferry Site Vice President Keith Polson spoke in June about the red finding and said TVA had budgeted nearly $140 million through 2015 on improvements. Polson said the red finding was "one of the biggest deals" for Browns Ferry workers to absorb.

"After the inspection I got emails from everybody asking 'how'd we do,'" Polson said. "It's very important to morale."

The federal warning status followed the 2010 discovery of a 600-pound valve blocking the primary emergency cooling line at Unit 1 at Browns Ferry. TVA at first blamed poor manufacturing, but NRC rejected the claims and indicated TVA's own inadequate testing, as the blocked line sat undiscovered for years.

The NRC determined that the broken valve would have prevented TVA from successfully implementing its shutdown procedure at the plant in the event of a fire.

A Browns Ferry engineer, who recently spoke out to The Huntsville Times and AL.com, said problems were worse. Public documents show a massive pump motor in a backup cooling line would also have failed, creating conditions where TVA may not have been able to cool the Unit 1 reactor in a worst case scenario.

Guthrie said NRC "was fully cognizant" that the pump motor failed a few days after the broken valve was discovered, meaning both the primary and the backup low-pressure cooling lines malfunctioned in October of 2010. But he said the NRC viewed the reasons for the failures separately.

"The point is even in 2010 we were fully aware of the problems with the valve and the RHR pump motor and we used all known conditions to determine it should be in Column 4," Guthrie said.