Nuclear Safety

Our First and Highest Obligation

Nuclear power plants are among the safest and best-protected private sector facilities in America, with monitoring and inspections by plant owners and the federal government.

All nuclear energy facilities in America are required to develop and test detailed emergency response plans to protect the public. The U.S. Nuclear Regulatory Commission (NRC) reviews and approves these plans and coordinates approval with the Federal Emergency Management Agency (FEMA).

State and local agencies develop detailed plans for the population within the 10-mile emergency planning zone, including plans for an evacuation in the unlikely event of an emergency. Zones out to 50 miles are geared toward protecting public health along with monitoring and protecting the food supply. Nuclear facilities are also responsible for sampling water, milk, soil, and crops within 50 miles of a plant.

The NRC also constantly evaluates new threat scenarios and protections in emergency preparedness in light of the threat of terrorist attacks. After September 11, 2001, the agency reevaluated its emergency planning and put additional practices in place. To further support preparedness for evolving and emerging threats, Constellation maintains open lines of communication with the Department of Homeland Security.

Constellation’s Planning and Preparedness

Constellation invests millions of dollars every year to be prepared for man-made and natural disasters. We also train local first responders and emergency personnel.

Like all nuclear facility operators, we regularly test emergency plans with local, state, and federal emergency response organizations. Every two years, we must conduct a full-scale emergency exercise with those same officials and organizations. If there's ever an actual emergency, the state's emergency management leaders would instruct the public to shelter or evacuate.

These plans are so meticulous that several communities have used off-site nuclear facility emergency plans in response to other types of emergencies. During the October 2007 wildfires in California, county emergency officials drew on relationships and communications links they had established during their years of planning for nuclear-related events.

The U.S. Nuclear Regulatory Commission (NRC) has permanent, on-site inspectors at all nuclear power plants. Environmental monitoring reports are regularly submitted to the NRC and are available to the public on the NRC website.

Many state environmental protection or public health departments also assign staff to monitor nuclear plants, and some conduct their own sampling and testing programs.

The U.S. Nuclear Regulatory Commission requires all nuclear plants to be able to withstand the most severe natural phenomena historically reported in a 200-mile area around each plant.

Constellation’s nuclear plants are designed to withstand extreme environmental hazards like floods and earthquakes. Watertight doors, elevation of equipment above potential flood levels, and engineered flood barriers protect emergency systems. Plant foundations, structures, and equipment are designed to withstand severe ground motion and flooding.

Defense-in-depth design ensures redundant, diverse, and reliable safety systems to supply water to the reactor core. Every safety system has at least one independent back-up system, and many have more than one.

Plant safety systems are also run by multiple, redundant power sources. Certain equipment is designed to automatically shut down the plant if the need arises due to a condition outside of normal operations.

Multiple physical barriers further serve to strengthen nuclear structures for safety. The first barrier is the fuel itself: the solid, ceramic uranium pellets. Pellets are sealed in metal fuel rods. The fuel rods are made of the metal alloy zirconium, which resists heat, radiation, and corrosion. The rods are bundled together into fuel assemblies.

Fuel assemblies make up the nuclear reactor core. The reactor core is inside the reactor vessel, which has steel walls that are about six inches thick. The reactor vessel sits inside a containment structure made of steel-reinforced concrete and is about five feet thick.

All of these layers are inside the reactor building, which is made of steel-reinforced concrete that is about four feet thick.

After the earthquake-related accident at Japan’s Fukushima Daiichi facility in 2011, the U.S. nuclear industry created the FLEX plan, a major step in addressing the critical problems encountered in the incident: loss of power and reactor cooling capability.

In the FLEX plan, vital back-up emergency equipment—generators, battery packs, pumps, air compressors, and battery chargers—is stored on site at each nuclear facility and also at two regional secure, offsite locations across the country. In a system with layers of built-in redundancy, FLEX provides yet another layer of backup power after a catastrophic event.

By design and construction, nuclear facilities are very difficult to penetrate. That, plus a well-armed paramilitary security force—and after September 11, 2001, multiple backup security systems—delivers layer upon layer of safety.

The nuclear energy industry maintains very strict security to prevent unauthorized persons from gaining access to critical equipment or approaching close enough to harm the facility either by land or air. America’s 62 nuclear sites are protected by sophisticated surveillance systems and approximately 9,000 highly trained, armed officers.

Before they become Constellation employees, job applicants must pass thorough background checks. Constellation then invests in initial and continuous training programs for operations staff.

Much of our operations training is done in a full-scale electronic simulator of a control room.

Initial training includes 12 weeks in the classroom, 25 weeks in the control room simulator, and 16 weeks of on-the-job training. Once an employee is licensed by the NRC, that operator will continually train by spending one week in a control room simulator for every five weeks spent on shift in the control room. Even our most senior reactor operators receive training every six weeks, for a total of 8.5 weeks of training every year.