As we watch the continuing catastrophe in Japan unfold with no clear expectations of the outcome, one thing is for certain: The safety of nuclear power has become a hot topic of conversation. While some countries are shutting down plants, many other are reevaluating the safety of theirs and strategizing over future plans.
In the U.S. we have 104 nuclear reactors. What are the chances that any of them could be home to an emergency like that at Fukushima Dai-ichi? The west coast would seem most at risk, given the busy San Andreas Fault. But an MSNBC analysis of data from the U.S. Nuclear Regulatory Commission (NRC) places the odds of an earthquake disabling the core of reactor elsewhere.
The NRC has calculated the odds of a quake causing catastrophic failure to a nuclear plant and has determined that for the typical nuclear reactor in the U.S., there is a 1 in 74,176 chance each year that the core could be damaged by an earthquake badly enough to leak radiation. As MSNBC puts it, that’s 10 times more likely than you winning $10,000 by buying a ticket in the Powerball multistate lottery, where the chance is 1 in 723,145. The odds take into consideration two main factors: the chance of a serious quake, and the strength of design of the plant.
In the ranking one would expect the top spot to go to the Diablo Canyon Power Plant, with its twin reactors nestled in between the Pacific coastline and the San Andreas Fault; or the San Onofre Nuclear Generating Station, amidst fault lines on land and under the ocean. But no and no. Nuclear power plants built on the California coastline have a lower risk of damage from earthquakes than those in other areas because they were designed and built with earthquakes in mind.
Meanwhile, plants in the East, South and Midwest, where earthquake risk wasn’t as highly considered in the design, now find themselves at the top of the NRC’s risk list. Why? Because geologists have learned a lot about the dangers of earthquakes in these areas. New faults have been found, and new computer models have changed predictions for how earthquakes may occur. According to MSNBC, the latest estimates are drawn from the 2008 maps of the U.S. Geological Survey. Of special note, the USGS said, was an allowance for waves of large earthquakes in the New Madrid fault area roughly centered on the Missouri Bootheel, as well as inclusion of offshore faults near Charleston, S.C., and new data from the mountains of East Tennessee.
The ratings, number 1 being the riskiest, are fascinating in that they also include the increase of risk (when available) based on how the USGS data changed from 1989 to 2008.