Nuclear Reactors in Earthquake Zones in the U.S. [Map]

Source photo via Flickr/heiwa4126

As we watch with baited breath to see if Japan can dodge a nuclear catastrophe, nuclear-powered nations themselves have succumbed to heavy scrutiny over both policy and safety. The United States leads the pack in operational nuclear power reactors with 104 total, and 32 additional reactors used in research. France comes in second with 58 reactors, Japan has 54 and Russia, 32 reactors. South Korea, India, UK, Canada, Germany and the Ukraine round out the remaining top ten, each with less than 20 reactors.

>> READ ALL THE COVERAGE: The Japan Earthquake, Tsunami, and Nuclear Crisis

While it might seem grossly opportunistic to discuss this while Japan is still reeling from the quake and struggling with their nuclear plants, it is well worth looking within our own borders to see if we are prepared for, or can avert, a similar disaster. California itself has two coastal nuclear plants with one less than a half mile from a fault line. Let's take a closer look at the US plants and where they fall along quake zones. In light of what happened in Japan, Germany has shut down all nuclear power plants that began operation before 1980; seven total. They will remain off until at least June. But France and the U.S. have no immediate plans to draw back from nuclear (or to even consider it), an odd stance for the U.S. as 2010 saw its share of nuclear safety near-misses.

Nuclear Reactors 101

Before diving into the doom and gloom, let's cover some nuclear reactor basics. There are essentially two types of nukes: boiling water reactor systems (BWR) and pressurized water reactor systems (PWR). The reactors at the Fukushima Daiichi plant are boiling water reactor systems. PWRs were originally designed to serve as nuclear submarine power plants.

Image via U.S. NRC

The operations of a PWR and BWR are basically similar. Water passes through the reactor core producing steam, the steam turns a turbine-generator producing electricity, and the steam is then converted back to water. Rinse and repeat.

Most U.S. plants are PWRs. Image via U.S. NRC

The biggest difference in the operation of the two reactor types comes down to producing and handling steam. In a PWR, the primary coolant flows through a series of tubes (no, not the Internet!) where it absorbs heat from the core but generates steam in a secondary chamber (see the above figure). In a BWR, a cool-water mixture is introduced directly into the core causing it to...boil. This steam, unlike that of the pressurized water reactor, is radioactive.

U.S. Nuclear Reactors

Nuclear power reactors. Image via U.S. NRC

There are currently 104 operational nuclear power plants in the United States--35 boiling water reactors, 69 pressurized water reactors--providing 20% of the country's electricity. The above map shows all nuclear power facilities across the country colored by years of operation.

Research and testing reactors. Image via U.S. NRC

In addition to those 104 nuclear power plants, there are 32 reactors used for research and testing at such places like laboratories and universities.

U.S. Seismic Activity

The U.S. Geological Survey (USGS) seismic hazard map show the probability level for an earthquake across the U.S. based on ground shaking, faults, seismicity and geodesy. This information helps dictate everything from building codes, insurance rates and public policy.

USGS National Seismic Hazard Map. Image via USGS

U.S. Seismic Activity Near Nukes

Looking at the overlap of U.S. nuclear reactors (both power and research facilities) and earthquake zones is pretty alarming. The West Coast isn't as peppered with nukes as the states east of the Mississippi are but they're sitting atop some pretty shaky ground.

Image via Public Integrity

Oddly, just two weeks before Japan was shaken by a 9.0 magnitude quake, 10 California lawmakers warned the U.S. Department of Energy that the state's two nuclear power plants are more susceptible to earthquakes than previously thought. Diablo Canyon was designed to withstand a 7.5-magnitude quake whereas San Onofre can only handle a 7.0. But in 2008, the USGS discovered that the Diablo (near San Luis Obispo) power plant was built less than a half mile from previously unknown earthquake fault and that San Diego's San Onofre plant is highly susceptible to both earthquakes and tsunamis. California is at risk for both.

The Cascadian Subduction Zone off the coast of British Columbia, Washington, Oregon and the northernmost part of California shook with a vigorous 9.0 on January 26, 1700. It produced a huge tsunami that its geological-mark on Humboldt County. It even reached Japan! But tsunamis from earthquakes around South America and the Aleutian-Alaskan region have posed a greater threat to the West Coast than locally generated tsunamis.


For example, the 1946 Aleutian tsunami produced waves heights of 12 to 16 feet at California coastal areas including Half Moon Bay, Muir Beach, Arena Cove, and Santa Cruz. The 1960 Chilean tsunami produced wave heights of 12 feet at Crescent City, California. The 1964 Alaskan tsunami generated waves of more than 20 feet at Crescent City, California, where it caused $7.5 million in damage and 11 deaths. It also produced waves ranging from 10 to 16 feet along parts of the California, Oregon, and Washington coasts. In contrast, the 1906 San Francisco, CA, earthquake produced local tsunami waves of only about 2 inches. The largest known locally generated tsunami on the west coast was caused by the 1927 Point Arguello, California, earthquake that produced waves of about 7 feet in the nearby coastal area.

But historical factors are only part of the equation. Japan's 9.0 earthquake not only shifted their coastline, it even moved an Antarctic glacier causing the West Antarctic Ice Sheet to drain more quickly. And reports are showing that San Francisco will be 5-feet further into the bay by the century's end, giving a 7-foot tsunami even more reach.

View the full-sized interactive map at maptd.

Climate change and the resulting shifts to our coastline must be considered especially as plants like Diablo Canyon seek renewal in 2024 and 2025. A process that begins years beforehand. Matt Freedman, an attorney with consumer group The Utility Reform Network in San Francisco, warns that "The NRC has typically rubber-stamped these license renewal applications."

Exactly when the Big One will hit California remains a mystery, but it will happen. Will we suffer through tsunamis and nuclear catastrophe? I do not know. It's all quite frightening to think about, and with the bad news from Japan still rolling in consistently, I am just going to take a breather and focus on bowling with cats. I suggest you do the same.


More on the Japan Tsunami
6 Important Questions About the Crisis at Japanese Nuclear Power Plants
Ongoing Crisis at Japan's Fukushima I Nuclear Power Plant
Japan's Nuclear Crisis Coverage at Discovery News

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