A “near-miss” at River Bend Nuclear Station near St. Francisville in May was one of 14 near-misses in 2012 at 12 nuclear plants across the country highlighted in a report the Union of Concerned Scientists released Thursday.

None of these near-misses caused any worker injuries or any harm to the public, said Dave Lochbaum, director of the Union of Concerned Scientist’s Nuclear Safety Project and the author of the report.

The frequency of the near-misses, however, is the problem, Lochbaum said.

“Given enough chances, it is only a matter of time before near-misses become an actual hit,” he said in the report.

However, representatives with the U.S. Nuclear Regulatory Commission say they don’t agree with the term “near-miss” since these were instances where the process worked, and small problems were identified and fixed before they become large problems.

“The whole system is designed to say, ‘Here’s a problem, we need to fix it before it’s something serious,’ ” said David McIntyre, public affairs officer with NRC.

The Union of Concerned Scientists report, “The NRC and Nuclear Power Safety in 2012: Tolerating the Intolerable,” outlines the successes and failures in how the U.S. Nuclear Safety Commission handled safety concerns last year at U.S. plants.

The Union of Concerned Scientists started as a collaboration between students and faculty at the Massachusetts Institute of Technology in 1969 and now includes more than 400,000 citizens and scientists, according to its website.

This is the third year the group has put together a report on the status of U.S. nuclear power plants and the effectiveness of the Nuclear Regulatory Commission.

This year, there were 14 “near-misses,” defined as an incident that prompts the commission to send out an investigation team, Lochbaum said.

“NRC is a lot like a sports referee: No one notices all the calls it gets right, they only notice the calls they get wrong,” Lochbaum said.

The near-misses have been happening at an average rate of one a month over the past three years, and steps need to be taken to reduce those numbers, he said.

One near-miss cited in the report occurred at the Byron Station in Illinois, where an electrical problem shut off power to emergency equipment, he said. Although employees got the equipment back on in eight minutes, “They should have never had to face that challenge,” Lochbaum said.

There appears to be no effort being made to see if a problem is really isolated or it’s a part of a bigger problem, the report said. One such incident occurred at the Harris nuclear power plant in North Carolina, where there was a problem with valves, and it was discovered that the company had stopped testing the valves in 2000, Lochbaum said.

“Neither the NRC or the company asked whether these were isolated events or just the tip of the iceberg,” Lochbaum said.

McIntyre, with NRC, said the agency is very focused on safety both within the agency and in the facilities that are regulated by the agency.

“I take issue with the term ‘near-miss,’ ” McIntyre said. “These (14 incidents in 2012) are evidence that NRC is finding and correcting it before it becomes a ‘near-miss.’ ”

Katie Damratoski, communications specialist with Entergy Operations Inc. River Bend Station, agreed and said the report doesn’t reflect the level of safety in the industry.

“The conclusions of the UCS report are counter to NRC inspections and industry trends that show industry safety performance is high. Further, the report misrepresents lower-level incidents as ‘near-misses,’ ” Damratoski wrote in an email.

“The report also provides an inaccurate view of the performance of River Bend by leaving out the overwhelming number of positive actions taken to ensure River Bend operates safely and reliably,” Damratoski added.

The incident at River Bend Nuclear Station in St. Francisville cited in the report involved an electrical problem that caused a small fire and a loss of power to half of the equipment cooling the core, he said.

When employees tried to start up the plant a couple of days later, all power was coming from one source and that power also was lost. A standby water system started operating and brought cooling water to the emergency equipment, according to the report.

“The plant responded exactly as it should have,” Damratoski said, citing the number of redundant systems the plant has to avoid large problems.

Victor Dricks, public affairs official in the regional office of NRC, said, “Far from showing lax regulations or oversight, the special investigations the NRC has conducted show the agency is doing its job protecting the public and environment.”

On Thursday, the NRC released annual assessment letters to all U.S. nuclear power plants as its annual report card of how they performed in the previous year.

River Bend Nuclear Station was included in the top tier of highest-performing reactors, meaning that plant met “all safety and security performance objectives,” according to an NRC news release. River Bend Nuclear Station was added to the highest-performance list because it had “resolved their issues since the reporting period ended,” the news release said.