A new Massachuesetts Institute of Technology (MIT) study, released May 15, reports that background radiation levels more than 100 times normal background levels show no DNA damage in mice, whose responses to radiation mimic those of humans. Current U.S. regulations require that residents of any area that reaches radiation levels eight times higher than background should be evacuated. However, the financial and emotional cost of such relocation may not be worthwhile, the researchers say. DNA damage does occur spontaneously even at low normal background radiation levels which average 300 millirems/year for everyone in the U.S. That damage is fixed by DNA repair systems within each cell, or humanity would not exist. Background radiation comes from breathing radon gas, cosmic rays, radiation in human bones and foods such as bananas and nuts, and from medical procedures.
MIT researcher, Bevin Engleward notes, “It is interesting that, despite the evacuation of roughly 100,000 residents, the Japanese government was criticized for not imposing evacuations for even more people. From our studies, we would predict that the population that was left behind would not show excess DNA damage.”
Nuclear energy advocates are pointing to the pollution-free, around-the-clock operation of nuclear plants, versus the harmful emissions from coal-fueled facilities that nuclear has the power to replace. Nuclear opponents retain the old fears, radiation and the issue of storing radioactive spent fuel pellets. They propose that renewables, especially wind and solar power, be used instead.
There are reasons the U.S. Nuclear Regulatory Commission <http://www.nrc.gov/> has so far approved 20-year operating extensions for 70 of the nation’s 104 nuclear power reactors with approval for the rest llkely.
First, the U.S. Bureau of Labor Statistics <http://www.bls.gov/oco/ocos227.htm> reports that nuclear plants average 0.34 accidents per 200,000 worker hours, compared with 2.3 for all U.S. industry.
Second, once amortized, nuclear plants can produce electricity for 2 to 3 cents per kilowatt hour, including fuel.
Third, U.S. nuclear plants have an uptime capacity operating factor of more than 90 percent, three times more than intermittent wind turbines. To duplicate a 1,000 megawatt (MW) nuclear plant requires at least 3,000 megawatts of wind power, plus backup natural gas plants for times when the wind speed is too high or too low.
Nuclear plants emit water vapor which rains out, but they emit no other greenhouse gases or pollutants like mercury or sulfur. And they don’t kill birds and bats.
The nuclear reactors developed for our Navy power vessels reliably and safely as they patrol on and under the world’s oceans. Those naval power plants were the prototypes for the larger-scale reactors that now provide 20 percent of U.S. electric demand.
A recent issue of the journal Science noted: “The electrical grid demands exquisite balance. At every instant, the supply of electricity throughout the system -- thousands of power plants, substations, and transmission lines -- must equal demand. If not, wires overheat, voltage drops, and circuit breakers snap open to protect parts of the grid.”
As to nuclear waste, the radioactive 5 percent of the spent fuel capsules that needs storage can be separated by reprocessing, as France does. The remaining 95 percent of the spent fuel is low-radiation uranium and 1 percent plutonium, all of which can be recycled. For the present, the Yucca Mountain site will work well for spent fuel storage. A new report to the U.S. Senate from the General Accounting Office (GAO) states that the Obama administration’s closing of the Yucca Mountain nuclear storage facility “was made for political reasons, not technical or safety reasons.” The issues blocking Yucca Mountain are political, not geologic.
The notion that intermittent wind and solar plants can replace the base load electric power supplied by coal and nuclear facilities has no basis in science or experience. Because wind blows intermittently, electric utilities must keep some of their conventional power plants in spinning reserve, ready to ramp up and down to balance renewable’s output. Recently, Bentek Energy, an energy analytics firm, looked at power plant records in Colorado. It concluded that despite big wind investments, wind-generated electricity “has had minimal, if any, impact on carbon dioxide emissions.’’
There is a role for wind and solar energy in our electrical future, but it’s a supplement, not a substitute, requiring substantial taxpayer subsidies. In 2011, wind and solar provided 122 billion kilowatt hours to the U.S. electric grid, about 3 percent of total demand. The Energy Information Administration is forecasting that wind and solar combined will provide less than 5 percent of our electric energy fuel in 2020.
A number of states, including Minnesota, have passed renewable-energy standards, calling for wind to provide 20 to 25 percent of electric energy by 2020. Passing legislation is quite easy; repealing the laws of physics and nature is not as simple.
Rolf Westgard, St. Paul, is a professional member of the Geological Society of America <http://www.geosociety.org/> and a member of the American Nuclear Society <http://www.new.ans.org/> . He teaches classes on energy subjects for the Lifelong Learning program at the University of Minnesota.