Waterford — Millstone Power Station meets all but one of the voluntary federal guidelines for protecting the public from damaged reactor cores, Nuclear Regulatory Commission inspectors have found.

The NRC issued inspection results Monday for all 104 operating reactors in the country regarding so-called “severe accident mitigation guidelines,” which all reactor owners voluntarily adopted in the late 1990s. On-site inspectors conducted the inspections at the request of the NRC task force, examining the lessons to be learned from the March 11 earthquake and tsunami in Japan, and the resulting damage, which included damage to some reactor cores and spent fuel pools at Fukushima.

Millstone owner Dominion, which operates two reactors and maintains one shuttered plant, maintains guidelines in three key places, a technical support center, emergency operation facilities and reactor control rooms. Millstone also includes guidelines in its periodic review or revision procedures. The only thing Millstone does not do is include the guidelines in drills.

By comparison, 97 percent of the country’s reactors kept the guidelines in the technical support center, but only 89 percent kept them in control rooms and 71 percent had them emergency operation facilities. About 42 percent have periodic review or revision procedures in place. Sixty-one percent use the guidelines for drills.

“While overall we believe plants are safe and all of the NRC’s efforts aim to ensure the plants never need to use these guidelines, we are concerned that our inspectors found many of the plants have work to do in either training their staff on these procedures or ensuring the guidelines are appropriately updated,” said Eric Leeds, director of the NRC’s Office of Nuclear Reactor Regulation.

Dominion spokesmen Ken Holt said in an emailed statement: “We continue to take full advantage of this opportunity to learn and apply the lessons from the Fukushima Daiichi accident as part of our continuous learning process. We are currently evaluating those improvements we need to make to ensure the health and safety of the public is maintained.”