Keep nuclear in the nation's energy mix

America's electrical grid was failing. In some parts of the country, natural gas generation could not produce because the gas was not available. Coal plants were shutting down because their coal piles were frozen. Forty thousand megawatts of forced outages almost plunged the Northeastern and Midwestern United States into darkness.

This scenario is not hypothetical: It happened in January 2014. This serious threat to our electrical grid was caused by the weather — by a "polar vortex" that slammed the country with prolonged extreme cold, freezing coal stacks and rendering natural gas unavailable.

It was an act of nature. It could just as easily have been an act of terror. And in its aftermath, one fact stood out: Almost all of the region's nuclear power remained operational throughout the crisis.

As the nation's first secretary of homeland security, it was my privilege to lead the department in those uncertain times after the 9/11 attacks. The department was and remains hyper-focused on events with substantial economic and security implications. Any contingency affecting the grid — polar vortex, terrorist act, cyber attack — certainly falls within that category. Only a grid built on diverse and stable sources of energy can withstand evolving threats and keep the lights on throughout America.  The goal of grid resilience cannot be met without nuclear power.

Energy Secretary Rick Perry ordered a review of America's electric grid April 14. He wrote, "Significant changes occurring within the electric system could have a profound impact on the economy and national security." America's security depends on energy sources that are stable enough — and diverse enough — to consistently meet demand. That's where nuclear energy and other forms of baseload power come in. The nation's nuclear plants are extraordinarily reliable, available over 90 percent of the hours in a year and with up to 24 months of fuel on site. Prices are less volatile than those of other energy sources. And nuclear plants produce no carbon emissions, which means cleaner air and better health for millions of Americans.

"The United States has been at the forefront of nuclear energy for nearly 70 years," former EPA Administrator Christine Todd Whitman wrote in 2015, "and the benefits it has provided to our health, the environment, and national security are countless."

Despite these benefits, today nuclear energy accounts for barely 20 percent of our power mix, according to the Energy Information Administration. And that share is declining as more plants come offline. While China has embarked on a high-profile campaign to build 60 nuclear power plants over the next decade, the U.S. has closed or retired 13 nuclear plants since 2012, with an additional 20 at risk of shutting down in the coming years, according to industry experts. If current trends continue, nuclear could fall to just 10 percent to 15 percent of our energy supply — a dangerously low percentage from a security standpoint.

This retreat risks another element of our national security: leverage over how other countries use nuclear power. When other nations buy Russian and Chinese nuclear exports — as they increasingly do — Moscow and Beijing, not Washington, set the standards. That is why I agree with retired Rear Adm. Michael Hewitt, who recently said, "We want to elevate the conversation to talk about nuclear power as an element of national power."

Reductions in our nuclear fleet would have a devastating economic impact as well. Just ask state and local leaders, who know firsthand how important nuclear energy is for reliable electricity, sustained investment in local economies, and jobs in their states. As governor, I ordered a restructuring of Pennsylvania's energy market in the mid-1990s to unlock the power of competitive markets to benefit the state. One thing we did not change, however, was the state's responsibility to meet federal laws — including goals for cleaner air. This is also why governors of both parties — including Republican Bruce Rauner of Illinois and Democrat Andrew Cuomo of New York — have recently supported commonsense initiatives to support nuclear plants that would otherwise retire prematurely.

The review ordered by Perry, another former governor, gives me confidence that our leaders will do what's necessary to ensure an energy mix that provides reliable electricity for defense and security operations — just as nuclear power has done, safely and reliably, for the last six decades. That review was reinforced by America's reliability watchdog organization, the North American Electric Reliability Corp., which informed Perry that "premature retirements of fuel-secure baseload generating stations reduce resilience to fuel supply disruptions."

As Congress and the administration work in the years ahead to advance economic opportunity while preventing threats to our security, they must strengthen and preserve our nation's baseload nuclear fleet, thus protecting our national security while ensuring a diverse, resilient energy grid.

Tom Ridge is founder and chairman of the risk-management consulting firm, Ridge Global.