With regard to nuclear reactors, Don Lichtenberg operates on the principle that “if things can go wrong, they will -- though not often.”
On March 31, Lichtenberg, professor emeritus of theoretical nuclear physics at Indiana University, spoke at the Monroe County Public Library on lessons on nuclear power that the United States can learn from the nuclear accident in Fukushima, Japan.
"Some reactors use 'natural' uranium, U-238, which has a half-life of some 4.5 billion years."Lichtenberg received a doctorate in theoretical physics at the University of Illinois and later joined the faculty of IU’s physics department. He taught and did research in subnuclear theoretical physics at IU for about 30 years, until his retirement. He wrote two books on physics and more than 100 original research papers. He has followed nuclear developments in the United States and abroad since 1945.
Though the National Academy of Sciences has said there is no safe dose of radiation, Lichtenberg asserted the statement is controversial. However, he conceded, “It is prudent to assume there is no safe dose. If this assumption is wrong, no harm is done. But if one assumes there is a safe dose and there isn't, harm is done.”
The United States, Lichtenberg said, depends on nuclear power for about 20 percent of its energy; France depends on it for about 75 percent and Japan for 25 percent.
“We are prepared for average trouble, not the worst,” Lichtenberg said. “If any country is prepared for earthquakes and tsunamis, it’s Japan.”
Japan wasn’t prepared for the Richter scale 9 magnitude earthquake and 45-foot tsunami that ravaged the nuclear reactors on March 11. Anecdotal evidence, Lichtenberg said, indicates that the earthquake was the greatest in the last 500 years. Japan was unprepared for such devastating natural disasters.
Human error caused the accidents at Three Mile Island in 1979 and the more severe one in Chernobyl, Ukraine, in 1986.
The Daiichi reactors in Fukushima lost power and “went bad,” according to Lichtenberg, because of the earthquake and tsunami. Whether they’re turned on or off, nuclear reactors need to be cooled continuously, or they overheat and emit radiation. To make matters worse, the cooling system for the spent fuel rods maintained in pools of water at the Daiichi site also failed, causing more emissions of radiation.
"The world’s pools contain more spent fuel rods than they were designed for."
The heat was so intense, Lichtenberg said, that it ionized the water, separating the hydrogen and oxygen, and chemical explosions occurred from the hydrogen.
A meltdown occurs when fuel rods in the reactor become so overheated that they melt, causing radiation to penetrate the protective concrete walls around the reactor and seep into the soil. Several Daiichi reactors underwent at least a partial meltdown.
The Daiichi accident released radiation into the air, water and soil. And Japanese officials have upgraded their damage assessment to equal the one in Chernobyl. As a result, some food became contaminated and “not safe for human consumption,” Lichtenberg said. “Of course, the damage from Fukushima is not over. In the worst case, the damage could exceed Chernobyl. We'll have to wait to see how it plays out.”
The United States, Lichtenberg said, has 104 nuclear reactors, 23 of which have the same design as the six Daiichi reactors (General Electric Mark I). They are “boiling water” reactors, which use uranium to heat water to create steam, and the steam turns a turbine that generates electricity.
Japanese officials ordered the evacuation of residents living within 18 miles of the crippled reactors, but the U.S. government told its nationals living in Japan to evacuate within 50 miles of the reactors, Lichtenberg pointed out.
That there haven’t been more nuclear reactor accidents derives from the fact that some reactors have safety features that others lack and can resist some human errors, Lichtenberg said. No reactor can survive an earthquake and tsunami as serious as the ones in Fukushima.
If the Indian Point nuclear reactor, about 35 miles from New York City, were to fail and required evacuations, as many as 20 million people would have to be evacuated. “It can’t be done,” Lichtenberg stated.
Lichtenberg is opposed to constructing new nuclear reactors for three reasons.
One, such reactors aren’t economically viable, he said. The companies that construct and operate them don’t have the necessary money. It’s only subsidies by the taxpayers that allow the construction and operation of nuclear reactors. He questioned whether we should subsidize a technology that has a small chance of undergoing accidents but a “very, very large potential” for disastrous damage to human health and the environment when accidents occur.
Two, a terrorist attack or “almost anything” could cause a nuclear accident, Lichtenberg said. Though the potential for an accident is “small,” the potential for damage is “very, very large.” The six Daiichi reactors contain more radioactive material than Chernobyl; if it all escapes, the disaster will be greater than Chernobyl’s.
"Nuclear energy isn’t renewable; there’s a limited quantity of uranium buried in the earth."
Three, Lichtenberg said, there is no method of permanently storing the waste products of nuclear power. Under normal operating conditions, the fuel rods become “poisoned by waste” and have to be stored and kept cool in the pools of water adjacent to the reactors so they don’t overheat. Currently, the world’s pools contain more spent fuel rods than they were designed for.
Lichtenberg said that when atoms that constitute enriched uranium (U-235) are split (fission), they release a million times as much energy as that released by chemical reactions, including coal burning. Some reactors use “natural” uranium, U-238, which has a half-life of some 4.5 billion years. U-235, which is used in nuclear weapons as well as some reactors, has a half-life of about 700 million years.
A half-life is the time it takes half the atoms of a radioactive substance to disintegrate.
According to Lichtenberg, the physics community is divided on the use of nuclear reactors. Some think the risks of greenhouse gas emissions and increasing global climate change are more serious than those nuclear reactors pose. The mining and burning of coal, Lichtenberg said, pose a greater health problem than reactors do; throughout the world each year they cause thousands of deaths, many more than a normally operating nuclear reactor causes. But there is always that potential for a very rare disastrous accident with a nuclear reactor.
The public is fearful of nuclear power and is willing to accept more deaths from the mercury, sulfur dioxide and other pollutants that coal plants emit than they are from nuclear reactors, Lichtenberg said.
He thinks we should not rely on at all on nuclear energy for electricity but rather on renewables, such as wind, solar and geothermal energy. Nuclear energy isn’t renewable; there’s a limited quantity of uranium buried in the earth.
Lichtenberg said he believes “nuclear energy is a gamble that we shouldn’t do at all.”
Most of all, Lichtenberg said, we need conservation; energy efficiency is the cheapest way to use less energy. Wind and solar don’t require heat and steam to produce electricity, as do nuclear reactors and coal plants. Nuclear reactors don’t emit greenhouse gases, but their negatives outweigh the positives, in his opinion.
We don’t know, according to Lichtenberg, how significant the health effects are from the radioctive iodine that’s reaching the United States from Fukushima. I-131 has a half-life of about eight days. Taking iodine pills can help prevent the thyroid cancer that iodine I-131 causes. People can do nothing to prevent the health effects of radioactive cesium and other elements leaking from the Daiichi reactors.
"Most of all, Lichtenberg said, we need conservation; energy efficiency is the cheapest way to use less energy."
Plutonium, the most deadly radioactive material and used by some nuclear reactors, has a half-life of 24,000 years, Lichtenberg said, and nothing we can do will counteract its effects -- cancer, birth defects and death. “How can we be sure,” he said, “that storage sites will remain safe for thousands of years?”
Existing reactors can be retrofitted for greater safety, but we probably should shut down U.S. reactors that are near earthquake faults or large cities. And no more should be built, Lichtenberg said.
“There are too may unknowns connected with nuclear energy for me to have any confidence in building more of them,” he said. Furthermore, Americans are making a mistake if they rely on regulators to keep them safe because regulators are “in bed with the people they’re supposed to regulate.”
Linda Greene can be reached at .
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