I have posted a lot of articles about threats to nuclear reactors. Aside from problems originating within a power plant like fires, explosions and meltdowns, I have talked about hurricanes, floods, earthquakes and other external threats. But it turns out that there are threats to our nuclear reactors that are literally out of this world.
We generally think of our sun as a stable source of life-giving energy. That is generally true but there are cycles of solar storms called sunspots that peak about every eleven years. If these storms are particularly intense, the wind of solar plasma that hits the radiation belts around the earth can cause problems for satellites and terrestrial electrical system.
In 1859 there was a severe solar storm called the Carrington Event that caused a huge coronal mass ejection (CMR). In about seventeen hours, the solar plasma hit the Earth and caused the biggest geomagnetic storm ever recorded. Auroras, commonly known as the Northern Lights, could be seen as far south as the Caribbean on the night of September 1. People in the Northeastern United States could read newspapers by the light of the auroras. Induced current caused telegraph systems all over the United States and Europe to fail. Some of the systems did continue to transmit messages even though they had been disconnected from their power supplies.
Analysis of ice cores from Greenland indicates that Carrington size CMEs occur between every one hundred and fifty years and every five hundred years on average. Events that are about one fifth the size of the Carrington Event happen several times a century. Powerful solar storms happened in 1921 and 1960, causing widespread problems in electrical systems and disrupting radio broadcasts. In 1989, a big solar storm caused a power failure over a large part of Quebec, Canada.
We are living in an electrical house of cards. It has been estimated that if we had a Carrington Event now, it would cause such massive damage to our electrical infrastructure that it would result in the end of our civilization. All electrical generation, transmission and utilization would be damaged beyond repair. All electrical communication systems would be gone. Gasoline to run vehicles is pumped with electrical pumps so combustion engines would soon be inoperable. Since we had a Carrington Event about a hundred and fifty years ago, we could have another one at any time. In addition, more frequent but less severe solar storms can still wreck havoc on our infrastructure including nuclear power plants. The problem at Fukushima was that they could not cool the fuel rods because external electrical power was cut off. This could easily happen to many reactors in the United States in the event of a serious solar storm.
The U.S. Nuclear Regulatory Commission is taking this threat seriously. They are currently coordinating with the National Aeronautics and Space Administration to understand the problem. They have concluded that the possibility of a severe solar storm is serious enough that they need to consider some sort of regulatory action for the U.S. nuclear reactors. Emergency planning and response capability in such circumstances need to be explored. A number of studies have concluded that the possibility of major solar flares taking down the U.S. power grid for months or even years would result in multiple meltdowns of U.S. reactors. It appears the threat to nuclear reactors from solar storms is more serious than even the threat of earthquakes and tsunamis. It is a good thing that the NRC is working on preparations for such solar events.
