Many of us in San Luis Obispo County are concerned about the Diablo Canyon nuclear power plant. The plant is around 25 years old and luckily hasn’t had any serious mishap that we know of. It does produce “clean” electricity in terms of its CO2 footprint. The dangers of a mishap are still present and what to do with the radioactive waste? So in terms of global warming, it is a help, but in terms of possible dangers, it is a potential menace to our community.
The vast majority of scientists would agree that global warming exists and that it is increasing in the last 50 years or so. For anyone who has studied the process, and the established science behind it, it is apparent that at least the primary cause of global warming is from human activity; specifically the production of CO2 and its release into the atmosphere.
The energy requirements for humans are great and the vast majority of these requirements are supplied by the burning of hydrocarbons (coal, gasoline, natural gas, etc.). CO2 is a byproduct from the burning of hydrocarbons and is the primary source of increased CO2 in our atmosphere. The CO2 is a “green house gas” which allows energy from the sun to reach the earth, but blocks much of the infrared radiation from leaving the earth thus heating up the planet. This heating up of the climate can be devastating to the systems that sustain all living beings. It seems logical that to avoid these changes in climate, we need to reduce the amount of CO2 in the atmosphere. Someone once observed that the first thing to do to get out of a hole you’ve dug yourself into, is to stop digging. Ergo, we should stop producing so much CO2.
There are many non CO2 producing technologies available to us to meet our energy needs. I would like to explore one that seems to be seldom discussed. That one would be nuclear energy and specifically the use of Thorium as a fissionable material. Until now, we have used uranium fission to produce electricity. This has been very expensive, potentially and in some instances actually dangerous.
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Thorium-powered reactors present a unique opportunity for a clean, safe and economical energy source. They run on the theory that by splitting a thorium atom with a neutron, energy is released along with 2 or 3 other neutrons which trigger more reactions thus keeping the reactor going for an extended period of time. The byproducts are minimally radioactive (much less so than uranium byproducts). Thorium has a half life of about 4 billion years and therefore it is minimally radioactive (much less than uranium or cosmic radiation we receive daily from space). Thorium reactors run at approximately 400 degrees centigrade and therefore don’t require high-pressure water systems uranium reactors require, making them safer than uranium reactors. Thorium needs to be in a solid state in order to work as a reactor. If the cooling system fails, Thorium melts to liquid form which automatically stops the reaction, thus shutting down the reactor. Uranium reactors, if allowed to overheat, will melt down and at the same time continue to heat up thus releasing radioactive material.
Thorium is about 200 times more efficient than uranium in providing energy. In addition, thorium is about 2000 times more energy dense than uranium. A thorium reactor produces about 90 percent less waste than a uranium reactor and the waste is radioactive for about 300 years as opposed to tens of thousands of years for uranium. The current uranium waste being stored for future burial could be used to help fuel the Thorium reactor. The cost of building a Thorium reactor is 35 to 40 percent that of a uranium reactor. Thorium is about four times as abundant in the earth’s crust than uranium and therefore is easier to find and mine. It doesn’t need to be enriched. The U.S. currently has tons of thorium stored which could be uses to start a program of Thorium reactors
Finally, Thorium doesn’t produce any plutonium as a byproduct and therefore can’t be used for weapons production. It would be interesting to hear the Iranians reaction to our helping them build a Thorium reactor. This would be a good indicator of their true intensions.
The technology for this kind of a reactor has been around for 40 to 50 years. A prototype was build at Oak Ridge lab in the 1960s and produced electricity for about five years. It was abandoned because we were at that time in a “cold war” with the Russians and wanted the plutonium to produce weapons of mass destruction. The Uranium reactor was the one that could supply the necessary materials.
The Chinese, Indians, Norwegians and others are currently trying to develop this technology and take out patents on it. Should they beat us in this race, they could have a monopoly on the technology; putting us at their mercy should we decide to use it. As a side interest, Thorium is found with other rare heavy metals which have become important in making high tech products. Their monopoly would give them an advantage in that area as well.
I would encourage people to become familiar with this technology so they can speak intelligently about it. Thorium reactors could play a major role in our quest for quest for energy independence and at the same time help alleviate the threat of climate change. Pressure should be placed on our congressional representatives to look into this technology and initiate a program to utilize this technology.
John Zinke, MD, is a retired physician living in Cambria.