Cumberland County was reminded of its most disastrous of disaster plans this week with an update to the Three Mile Island Plan.
The hopefully never-used protocol is required by federal agencies of all jurisdictions within a 10-mile radius of the Three Mile Island Nuclear Generating Station.
For the county, that includes New Cumberland Borough and a sizable portion of Lower Allen Township, according to county Public Safety Director Bob Shively.
“The plan basically requires us to provide mass reception, monitoring and possible decontamination of those residents within that 10-mile-radius portion,” Shively said.
However, the most recent revision to the protocol actually loosens those requirements. Cumberland County must now have public facilities available to house at least 10 percent of the population within the radius, as opposed to 20 percent before.
Those calculations, Shively said, are based on prior experience with other evacuation events, such as hurricanes.
If the county is required to have capacity for 10 percent of the affected population, it means federal planners are predicting that 90 percent of the affected population will be able to find shelter with friends or family and will not need public refuge.
“It was 10 percent, then they bumped it to 20, now it’s revised back to 10,” Shively said.
The bulk of that population would be sheltered at Big Spring High School under an agreement between the county and the Red Cross, Shively said. Further, some of Dauphin County’s evacuees would be housed in Shippensburg, Shively said.
Nuclear disaster and evacuation plans are overseen by the U.S. Nuclear Regulatory Commission, with further oversight from the Pennsylvania Department of the Environment’s Bureau of Radiation Protection, the Pennsylvania Emergency Management Agency, and FEMA’s Technological Hazards Division.
The partial meltdown of Three Mile Island in 1979 was the largest nuclear accident in the US and the catalyst for heightened restrictions on nuclear power that continue to this day.
The accident caused the release of radioactive gasses from the overheated facility, as well as fallout of radioactive iodine. Pregnant women and children within a 20-mile radius were advised to evacuate.
Although opinions vary, the most widely cited reports from the American Nuclear Society and the US Committee on Biological Effects of Ionizing Radiation have concluded that post-incident health effects, such as increased cancer rates, have thus far proven negligible.
The reactor that malfunctioned in 1979 was decommissioned. A second reactor was shut down after the incident, but returned to service in 1985 and is operational.