Calvert Cliffs neighbors able to take some comfort

There are no views of the Calvert Cliffs Nuclear Power Plant from any of the major roads that run through Lusby. Its two reactors sit in a wooded area along the Chesapeake Bay. The entrance is marked by a modest sign. But for those who live within its 10-mile evacuation zone, the plant makes its presence known in other ways.

There are siren towers and free supplies of potassium iodide pills at the health department. There is the feeling of unease on the part of drivers sitting in traffic on the two-lane Thomas Johnson Bridge — the main evacuation route for towns south of the plant. And then there are crises at other nuclear power plants such as the one at the Fukushima Daiichi facility in Japan triggered by last Friday’s massive earthquake and tsunami.

Graphic

A look at the total population increase on Solomons Island, the site of the Calvert Cliffs Nuclear Plant.

Many residents take comfort in knowing that Solomons Island doesn’t sit on a faultline the size of the San Andreas, and the Chesapeake Bay has more Atlantic sturgeon than it does tsunamis.

“The circumstances are completely different here. What’s more likely are hurricanes and tornadoes,” said Susan Shaw (R-Huntingtown), president of the Calvert Board of County Commissioners.

Shaw and others also note that there is a difference in the design of the reactors at the two plants. The Fukushima Daiichi plant has boiling water reactors, in which the water that circulates around the core turns into steam that is then used to turn turbines and generate electricity.

The Calvert Cliffs plant, by contrast, has pressurized water reactors, in which the water that circulates around the reactor’s core is kept under pressure so that it stays in liquid form. The liquid, which is radioactive, is then pumped through a series of tiny tubes. More water circulates around the tiny tubes and turns into steam used to generate electricity.

The difference in design, however, doesn’t necessarily make one safer than the other, experts said. The reactor at Three Mile Island near Middletown, Pa., which resulted in a partial-core meltdown, was a pressurized water reactor.

“They have different vulnerabilities to different events,” said Mohammad Modarres, a nuclear engineering professor at the University of Maryland.

Mark Sullivan, a spokesman for Constellation Energy Nuclear Group, which owns and operates the Calvert Cliffs facility as part of a joint venture with Europe-based EDF Group, said the plant has a “sterling” safety record, and is designed to withstand “natural events as big as would reasonably be expected to occur, with some extra safety margin built in.”

The Calvert Cliffs plant is designed to shut down “if certain seismic thresholds are met,” Sullivan said, though he could not name a specific earthquake magnitude. The Nuclear Regulatory Commission also requires plants be built to withstand natural calamities such as tsunamis.

Sullivan said the plant plans to deal with “even greater events if warranted.” Those plans are reviewed regularly by federal, state, and local government agencies. The plant, which is located about 50 miles south of Washington, also has training exercises and drills to ensure that staff can effectively carry them out.