Local governments need to step up emergency planning and public outreach regarding potentially harmful events that could occur if radiation is released into the areas surrounding the three nuclear power plants in Salem County, according to a nonprofit group.

A report issued by the Disaster Accountability Project criticized the Nuclear Regulatory Commission (NRC) for not expanding its current 10-mile emergency-planning zone around nuclear units, not only in South Jersey, but also at other locations.

Citing the Government Accounting Office, the report suggests that without such planning people outside of the 10-mile zone may choose to evacuate “even though they may be outside of the hazard area.’’

Such voluntary ‘’shadow evacuations’’ have the potential to complicate the evacuation of people most immediately in danger by clogging roadways, according to the GAO study.

In response, the NRC argued that such planning is unnecessary, saying that the current 10-mile planning zones provide an “adequate’’ level of protection of public safety in the event of an emergency at a nuclear power plant.

The report by the nonprofit group noted that the same federal agency recommended that U.S. citizens in Japan evacuate the area if they were located within 50 miles of the Fukushima nuclear power plant. A tsunami, triggered by a big earthquake, led to a partial meltdown of some of the units at that facility.

The nonprofit group wants to expand the planning zone to a 50-mile radius of the Salem plants, a step that would include Philadelphia and include more than six million people. The current 10-mile radius zone contains an estimated population of nearly 1 million people.

PSEG Power, the owner and operator of three of the plants, did not provide a spokesman to comment on the group’s report.

In support of maintaining the existing 10-mile planning zone, the NRC said state and local authorities ‘’have a robust capability to effectively evacuate the public in response to life-threatening emergencies.’’

The GAO report argued otherwise. “If the public outside the zone evacuates unnecessarily at a greater rate than expected, these ‘shadow evacuations’ would put additional traffic on roadways, possible delaying the evacuation of the public inside the emergency planning zone and potentially increasing the risk to public health and safety.’’

It also suggested that New Jersey, Delaware, Pennsylvania, and Maryland — all states within the 50-mile radius zone — should not wait for the federal government to act. They should voluntarily plan for emergencies beyond what is mandated by the federal government, it said.

“We’re looking for local jurisdictions (to do the planning) even if there is no mandate from Washington,’’ said Ben Smilowitz, executive director of the Disaster Accountability Project, an organization that aims to provide independent oversight of disaster-management systems.

According to a survey by the project, most jurisdictions between the 10-mile and 50-mile radius have no emergency plans and no public education outreach related to the nuclear units located in Salem, the second-largest nuclear complex in the nation.