Waterford — The Nuclear Regulatory Commission has notified officials at the Millstone Power Station that the plant faces possible enforcement action after a Nov. 24 inspection uncovered two findings related to security requirements, one preliminarily determined to be “very low” safety significance, and the other of “greater than very low” significance.

Because the issues pertain to security systems and procedures that are protected from public disclosure, the NRC did not describe the nature of the problems. NRC spokesman Neil Sheehan and Ken Holt, spokesman for Millstone, both emphasized Tuesday that the issues were corrected immediately after they were identified.

The new findings are the latest in a series of safety and security deficiencies the NRC has found at the nuclear power plant over the past year. Bill Sheehan, head of the citizens’ panel that oversees safety-related issues at Millstone, said the latest findings are further evidence that there may be a systemic problem at the plant. He is not related to Neil Sheehan.

“After years with no problems, all of a sudden there are a bunch of findings,” said Sheehan, chairman of the Nuclear Energy Advisory Council. “That’s at least a yellow flag, if not a red flag. Why suddenly does it look like they’re having performance problems?”

Sheehan of the NRC said the agency has asked Millstone owner Dominion Resources to participate in a conference to discuss the new findings. It plans to issue a final determination on the findings within 90 days.

In a letter to David Heacock, president and chief nuclear officer of Dominion, the NRC said that “one or more of the findings are also apparent violations of NRC requirements and are being considered for escalated enforcement action.” The NRC may determine that additional inspections, regulatory actions and oversight of the plant are warranted, the letter said.

The company has agreed to participate in the conference with the NRC, Holt said. He declined to comment further.

David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists, noted that of the 125 findings during NRC security inspections at the nation’s power plants in 2013, only four were rated higher than “green,” the lowest level of significance. The NRC rates inspection findings on a four-tier, color-coded system, in which green is the lowest, followed by white, yellow and red. One of the two new findings at Millstone was rated “green” while the other was described as “greater than green,” with precise coding to be assigned when the NRC finalizes its inspection report. Examples of the types of security violations found by NRC inspectors at plants elsewhere in the country include openings in a fence that could have allowed unauthorized access and a guard who fell asleep on the job, Lochbaum said. In that case, the plant owner was fined $70,000 and the guard was fired.

While having a “greater than green” security finding is unusual, Lochbaum said, the public and Millstone workers can be reassured that the problems have been identified and corrected.

“I take some comfort that the NRC found the problem,” he said. “The best news to me is that whatever it was, it’s no longer a threat to people who live around the plant or the workers. But for the plant, it is embarrassing to have someone else find your problems.”

He said the series of recent findings at Millstone raises questions about the plant, but it is too soon to say whether they indicate a larger problem.

“They did have more than their share of safety problems last year,” he said.

Millstone is already under increased NRC oversight until June 30 due to a “white” finding of “low to moderate” safety significance for failure to promptly identify and correct repeated problems with a feedwater pump that is part of reactor safety systems. In addition, in May the plant was subjected to a special NRC inspection because of an unplanned shutdown of both operating plants at the power station. There were also two special inspections of the feedwater pump last year. The May inspection resulted in the NRC issuing a “severity level 3” violation for the plant’s power line outage detection system, after inspectors determined that Millstone staff could have taken steps to avoid the sequence of events that led to both units going offline.

Last fall, the citizens advisory panel grilled Millstone officials about the recent special inspections and findings, questioning whether there has been slippage in attention to safety, training, expertise or other areas.

In a response to the concerns raised by the panel, Stephen Scace, site vice president of Millstone, said station management looked for a “root cause” among the various events and did not find one. Scace responded in a Nov. 10 letter included in the advisory panel’s 2014 annual report, posted Dec. 11 on the state Department of Energy and Environmental Protection’s website.

Scace said staff also evaluated “safety culture implications” of the events and concluded that “there were no aspects of safety conscious work environment that we found lacking.”

He added, however, that two areas were identified for improvements to Millstone’s safety culture.

“Specifically,” he wrote, “there is room to improve in the area of problem identification and evaluation; and establishing clarity around decision making. As a result, we have implemented performance improvement actions to address these areas.”

In addition, he said, Dominion is assembling a team of its own and industry resources who will work “to ensure Millstone’s performance meets both your and our expectations.”

j.benson@theday.com

Twitter: @BensonJudy