Implementation of post-Fukushima resilience upgrades at the Oyster Creek Nuclear Power Plant in Lacey Township will be up to the federal regulators who ordered them in the first place.

Exelon has applied to the Nuclear Regulatory Commission (NRC) for a compliance extension to January 31, 2020 - shortly after the plant's scheduled closure.

Oyster Creek is among the generating stations now required to be equipped with hardened vents from the wetwell, or cooling-water reservoir; and from the drywell, or enclosed section around the reactor.

The vents, as determined by the NRC's study of the Japanese disaster, would mitigate the effects of combustible gases that triggered explosions at the flooded Fukushima Daichi reactor.

In its application, Exelon estimates the start of work to begin in autumn 2016 for the wetwell vents, and fall 2018 for the drywell vents. Both land within an acceptable start-date range under NRC's directive.

However, company executives seek the extension for project startups based on the short span of time until closure. They also cite Oyster Creek's Isolation Condenser System and severe accident mitigation (FLEX) strategies, NRC says.

A spokesman for the agency says that its decision might require as much as a year to reach.