When a 100-year earthquake and powerful hurricane delivered a one-two punch on the East Coast, some in the media focused on nuclear energy facilities in harm's way. The coverage raised the inevitable question: Would the facilities be able to withstand Mother Nature's wrath?

At least a dozen nuclear energy facilities, from North Carolina to Michigan, registered vibration from the August 23 earthquake. The temblor hit hardest at the North Anna Power Station in central Virginia, located about 10 miles from the quake's epicenter. Four days later, many of those same plants and a few others - 15 plants, total - were in the path of Hurricane Irene.

So what happened? As planned, not much.

Layer upon layer of safety systems and exacting preparedness procedures worked in every case.

A handful of nuclear energy facilities, including North Anna, reduced power production or shut down as a precautionary measure. When needed, locomotive-sized diesel generators kicked in to power critical safety systems. Although some alarmists cited the plant shutdowns as a sign of trouble, they were precisely the opposite. In cases where there are sustained hurricane force winds or extreme flooding, nuclear energy facilities shut down to ensure that no problems develop as a result of these events.

In some cases, the companies that operate these reactors will declare these situations as "unusual event." Alarmists latched on that term as a cause for concern. As defined by the Nuclear Regulatory Commission, an "unusual event" is an out-of-the-ordinary occurrence that does not involve any expectation of a serious problem. It is an issue that requires attention, not a sign of danger.

In the past few months, U.S. nuclear plants repeatedly have maintained high levels of safety even in the face of major storms. That's what they are designed to do. When Hurricane Katrina devastated New Orleans and much of the Gulf Coast in 2005, Entergy's Waterford nuclear energy facility, just 20 miles from New Orleans, rode out the storm without incident.

When a series of tornadoes destroyed transmission lines and ravaged the area around the Tennessee Valley Authority's Browns Ferry reactors in Alabama in April, the three reactors shut down safely and seven huge emergency generators supplied backup power - all according to plan.

This isn't a matter of testing fate. All U.S. nuclear energy facilities are designed to withstand floods, fires, earthquakes, tornadoes, hurricanes and other catastrophic events.

These robust design standards match the characteristics of each plant site, so that natural threats specific to certain parts of the country are addressed-with an extra margin of safety added to it. The Nuclear Regulatory Commission (NRC) reviews these standards as part of its licensing process both for the reactor designs and each facility license. In fact, the NRC is currently reviewing earthquake standards for plants in the Central and Eastern United States - a process that began long before the recent quake.

The nuclear energy industry's approach to safety includes a continuous focus on operational procedures, extensive training, sharing lessons learned and emergency preparedness, as well as a heavy reliance on redundant safety systems.

Some critics of nuclear energy seized on the fact that one of the four backup generators at North Anna was taken out of service after developing a coolant leak. They overlooked the fact that the remaining three generators would have been sufficient to keep the reactors cooled indefinitely. That is precisely why nuclear plants rely on layer upon layer of safety systems - piling safety on top of safety in case something doesn't work as planned.

We should never become complacent about safety at nuclear energy facilities. The issue is too important; the energy too critical to our homes and businesses. When the next storm hits, our record shows that U.S. nuclear energy facilities will be ready.