Unresolved safety-risk findings that developed in 2014 at the Oyster Creek Nuclear Power Plant in Lacey Township mean new ongoing federal inspections, perhaps through mid-2016.

The Nuclear Regulatory Commission (NRC) has not yet finalized preliminary findings regarding a diesel backup generator that malfunctioned and faulty electromagnetic relief valves.

A third issue, exceeding the NRC's limit on unplanned outages in a 7,000-hour time frame, was resolved in the plant's favor in light of a return to normal operations in the last quarter of 2014.

NRC spokesman Neil Sheehan says that final determinations follow an evaluation of documents that Exelon has submitted.

"Exelon has provided its response to us. The company did not request a meeting to discuss the issues," Sheehan said.

At that point, the agency will issue a final determination as to whether the generator matter is given "white" classification (low-to-moderate safety significance) and the valve issue is given a "yellow" classification (substantial safety significance).

Low safety risks are classified "green."

The duration of a new round of inspections will depend on Exelon's notification that "it's conducted a thorough root-cause evaluation; that it's checked on what we describe as an 'extentive condition,' that is, whether these problems could affect other parts of plant operations; and whether they've put in place the appropriate fixes," Sheehan said.

The nation's oldest functioning commercial nuclear reactor is of a design no longer even used. It has operated continually for 46 years as of 2015. In Sheehan's observation, the failures are not characteristic of Mark 1-designed power plants.

"We've not seen a set of circumstances where an emergency diesel generator fan driveshaft ended up snapping in two," Sheehan said. But he added that the valve issue was really out of Exelon's control to begin with.

"What we've seen, so far, is that the company did not have an opportunity to identify it previously.There really was no industry knowledge of this potential condition," Sheehan said.

NRC maintenance requirements direct operators of plants of any age to continually watch for aging-related conditions. "This is not only an issue that Oyster Creek's going to have to address, but that will be shared with other plants," Sheehan said.

The inspections will extend beyond the specified malfunctions, according to Sheehan.

"If they have other diesel generators, have they checked the driveshafts on those...have they checked the maintenance procedures on those. On the electromagnetic valves, is there a problem with other valves that may not have been observed because they weren't looking for the right things or in the right places," Sheehan said.