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Photo courtesy of the Calvert Cliffs Nuclear Power PlantAerial view of the Calvert Cliffs Nuclear Power Plant. The two domed buildings are the reactor containment buildings.
The United States embassy in Tokyo advised Americans living in Japan on Thursday to evacuate a minimum of 50 miles away from the burning and exploding nuclear reactors at Fukushima, damaged two weeks ago by an earthquake and ensuing tsunami.
If such a radius was applied to Southern Maryland with the center located at the Calvert Cliffs Nuclear Power Plant in Lusby, it would include an area stretching to Washington, D.C. in the north; Salisbury in the east; nearly the entire Virginia Northern Neck to the south; and to Stafford, Va. in the west.
Yet Maryland's published emergency response plan for a nuclear disaster at Calvert Cliffs is focused on a 10-mile radius including only the southern end of Calvert County, a slice of Dorchester County coastline, and a stretch of St. Mary's County's eastern side, stretching from Oakville to the Patuxent River Naval Air Station.
This 10-mile radius is known as the Protective Action Zone, and the state stockpiles iodine tablets in this area for residents to protect their thyroid glands from radiation exposure. But according to officials, the state also has a plan for the evacuation and protection of a 50-mile radius, known as the Ingestion Pathway Zone.
According to David Zylak, public safety director for St. Mary's County, his team drilled last year to practice instituting the 50-mile radius plan, which also includes protecting and decontaminating food sources, such as livestock and crops.
He said his team drills for a 10-mile evacuation every two years and will do so again in September.
But "we have a 50-mile map as well," Zylak said.
Zylak said the 10-mile plan is triggered if there is an incident at the Calvert Cliffs plant, but the 50-mile plan only kicks in if there is an actual release of radioactive material from the plant.
Richard Muth, executive director of the Maryland Emergency Management Agency, confirmed Zylak's information and noted that his agency is in constant contact with the county's public safety department.
"We have plans in place for these [nuclear] plants," Muth said.
Mark Sullivan, director of communications for the Constellation Energy Nuclear Group, said safety was the company's top priority for Calvert Cliffs.
"We have emergency response plans in place which are approved at the federal, state and local government agencies," Sullivan wrote in an e-mail. "The plans have detailed procedures which are routinely reviewed and used in training of our teams. We have training exercises and drills to test our ability to effectively implement our plan and are formally evaluated by the NRC."
Sullivan also said Calvert Cliffs' reactors would be shut down if certain levels of seismic activity were detected in the area and that the NRC required all plants to be designed to withstand natural phenomena like tsunamis.
According to the U.S. Geological Survey, there has never been an earthquake centered in the Washington, D.C., area in recorded history (though the area has felt mild effects from quakes centered elsewhere).
Dr. Jeff Halka, director of the Maryland Geological Survey with the Maryland Department of Natural Resources, said there is a 2 percent probability in 50 years of any earthquake occurring in Maryland, and even if one did strike, there is an almost zero percent chance that it would ever be as large as the quakes around the Pacific Rim.
"We're not in an area of active mountain building. We're not in an area of continental drift causing one oceanic plate to go under another," Halka said. "The East Coast of the U.S., we haven't been in that situation for some hundreds of millions of years when the Appalachian Mountains were formed."
However, because earthquake predictions are by and large based on an area's seismic history, the possibility of a Maryland quake can never be overruled, he said. "Most of the East Coast has a low probability, except for Charleston, South Carolina because Charleston had a big earthquake" at the end of the 19th century, Halka said. "Nobody really knows what the cause is. Obviously there's a fault somewhere, but it doesn't express itself at the surface."
Nathan Hultman, a University of Maryland professor in the School of Public Policy who is an expert on atomic energy policy, said reactor containment units in the United States are built to withstand tremendous impacts — even the force of a plane flying into them, a scenario illustrated by the terrorist attacks of Sept. 11, 2001.
But Hultman said the cooling ponds where used nuclear rods are placed at most facilities are sometimes more vulnerable. Spent rods must be radioactively cooled for several years before they can enter "dry cask" storage. Fires have broken out in some of the pools at the damaged Fukushima plant, sending high levels of radiation into the atmosphere.
"Even if someone did try to fly an airplane into a nuclear reactor ... it's likely not going to actually break the reactor and release radioactivity," Hultman said. "But if you fly the airplane into the pool of spent fuel, you can create essentially a dirty bomb, right, from just this activity and maybe even set the thing on fire."
Sullivan wrote that the spent fuel at Calvert Cliffs is stored in a hardened facility.
"The spent fuel at Calvert Cliffs … [is] stored in auxiliary buildings designed to withstand the design basis earthquake as well as all other natural phenomenon," he wrote. "As a result of enhancements implemented after Sept. 11, our sites have additional capabilities to handle beyond design basis events, including the capability to provide cooling to the spent fuel pool in the absence of electrical power. This capability includes equipment (diesel-driven pumps, hoses, valves, etc.) that has been pre-staged at the plant. Personnel are trained in their use."
NRC spokesman Neil Sheehan said the type of reactor involved in the Japanese emergency is the boiling-water reactor, or BWR. Both Calvert Cliffs units are pressurized-water reactors, or PWRs. The spent fuel pool in the PWR is located outside the containment building, rather than on top of it, as is the case with certain BWR designs. The overhead placement at Fukushima Daiichi led to problems in the days following the earthquake and tsunami.
David Saleh Rauf and Jesse Yeatman contributed to this report.