As a native San Franciscan, I know firsthand the destructive power earthquakes can have on lives, property and critical infrastructure.
Luckily this week's 5.8 magnitude earthquake, with an epicenter in Virginia, caused minimal damage and thankfully no loss of life.
The earthquake did cause two nuclear reactors at the North Anna Nuclear Power Plant in central Virginia to lose power, requiring the deployment of back-up diesel generators.
The incident was a stark reminder of how vulnerable America's nuclear power plants are to natural disasters.
Uninterrupted electricity is essential for nuclear safety. Without electricity, nuclear power plants are unable to pump cooling water through reactor cores and spent fuel pools to prevent overheating and fuel melting.
Without power, plant operators cannot control reactor activity or remotely monitor spent fuel.
It was the loss of electrical power that led to the partial-meltdown of multiple reactors, significant radiation release and damage to the spent fuel pools at the Fukushima Daiichi plant in Japan after the devastating 9.0 earthquake and tsunami in March.
Nuclear power provides 20 percent of our nation's energy and 70 percent of the zero-carbon electricity in the United States.
Nuclear has a future in our country's energy mix, but we must ensure that our domestic plants are designed to both endure the threats we can foresee and respond to scenarios we never imagined.
Shortly after the disaster in Japan, I visited California's two nuclear power plants--San Onofre and Diablo Canyon -- to review safety protocols. Both of these plants are similar to the North Anna plant in Virginia.
I have also reviewed reports issued by the Blue Ribbon Commission on Nuclear Waste and the Nuclear Regulatory Commission (NRC) Task Force on the disaster in Japan.
These expert reports, the recent East Coast earthquake and my own experiences provide the following lessons:
First, our country needs a comprehensive, national policy to address the management of spent fuel, the radioactive waste produced while generating electricity by fission.
The Nuclear Waste Policy Act required the federal government to begin storing nuclear waste on a long-term basis in 1998. In reality, radioactive spent fuel is today stored at reactor sites -- at enormous taxpayer expense -- because there is no current alternative to this system. The liability for this de facto permanent storage will cost taxpayers more than $15 billion through 2020.
In California, radioactive waste continues to await federal pickup at two sites, even though the reactors are decommissioned. At our two active reactors, spent fuel removed from reactors in 1984 is still cooling in wet spent fuel pools.
In Japan, there were no problems with the hardened dry casks that stored spent fuel without need for electricity. But there were major problems with spent fuel pools, which are very similar to fuel pools at U.S. reactors.
The tragedy in Japan proved that we desperately need to make on-site storage safer and find a way to remove stockpiled waste to safer, more secure regional sites.
Second, today's efforts to protect against seismic and flooding hazards may not be sufficient.
Japan's nuclear disaster earlier this year occurred because the earthquake and tsunami vastly exceeded the design parameters of the Daiichi reactors.
Virginia's reactors were designed to endure a 6.2 quake -- larger than what struck this week -- so safety systems functioned as designed.
Unfortunately, many U.S. reactors were built decades ago when we knew less about flooding, seismicity and other threats. But the NRC does not consider new information on threats -- including earthquakes -- when it relicenses nuclear plants. The NRC's own task force in July recommended that this policy be changed.
Third, we must improve the redundant safety systems to respond to disasters.
A prolonged blackout in Japan caused by the earthquake and tsunami degraded the ability to prevent and mitigate disaster.
In Virginia, no prolonged blackout occurred. Backup systems were required for less than 24 hours.
The NRC should work closely with plant operators to make sure nuclear power plants can safely cool fuel and monitor systems during a prolonged loss of electrical power.
Finally, for spent fuel stored at reactor sites, dry casks are safer and more secure than permanent storage in spent fuel pools.
A 2006 report by the National Academies of Science found that dry cask storage has inherent safety and security advantages over wet pool storage. Even with that knowledge, 50,000 metric tons of spent fuel is stored in pools throughout the country.
Thankfully, this week's earthquake caused little damage and nuclear plant backup safety systems worked as designed.
But the earthquake -- in an area of the country not known for the type of seismic activity that occurs on the Pacific Ocean's "ring of fire" -- is proof that Mother Nature can act whenever and wherever she wants.
If we are going to rely on nuclear power to generate energy, we must improve safety and establish a comprehensive, national policy to address the management of nuclear waste.
At present, we lack that national policy. The Virginia earthquake was thankfully not a Japan-style disaster. We need to learn the lessons we can to assure that next time we are ready -- not just lucky.
Senator Dianne Feinstein (D-Calif.) is Chairman of the Energy and Water Appropriations Subcommittee.