Russian forces this month attacked the Zaporizhzhia nuclear power plant in Ukraine, the largest nuclear power plant in Europe, damaging several facilities in the process.
The Ukrainian State Nuclear Regulatory Inspectorate warned that “the loss of the possibility to cool down nuclear fuel will lead to significant radioactive releases into the environment,” which could exceed all previous accidents at nuclear power plants, including the Chernobyl accident and the accident at the Fukushima Daiichi nuclear power plant. ”
However, is it really so?
This incident raises many questions, the majority of which have been answered by many of my colleagues and experts in recent days in the media. There are other equally important questions that I seek to find an answer to today: How safe, or dangerous, are modern nuclear plants? Is nuclear an answer, or an enemy, to solving the climate crisis?
I discussed this and other vital questions with Howard “Cork” Hayden, professor of physics emeritus in the physics department of the University of Connecticut.
Hayden’s research involves accelerator-based atomic physics and energy for society (fossil fuels, nuclear, hydro, wind, biomass, photovoltaics, solar heating). He is an author of “Energy: A Textbook,” written for people who want to be able to discuss energy with confidence, and editor of The Energy Advocate, a monthly newsletter promoting energy and technology.
During our discussion, we touched upon many topics – from global warming to discussing the problem of having a plethora of scientific units of measurement. We even did some math.
Here’s an excerpt of our discussion, focusing on nuclear energy:
Q: Are nuclear plants safe to operate? What about Three Mile Island? Chernobyl? Fukushima?
A: First and foremost, it is quite literally impossible for a nuclear reactor to explode like a bomb. It can not happen, no matter what goes wrong.
Second, there is no such thing as safe energy. To ask for safe energy is to ask for gasoline that will not burn. What matters is how much hazard there is per unit of energy delivered. On this topic, nuclear very clearly has the best record.
We have produced electricity with nuclear reactors since the 1950s, and they presently provide about 20% of our electricity in the US To date, not a single individual has been harmed by radiation from any nuclear power operations. That claim can certainly not be made for any other energy source.
There have been three notable nuclear accidents. The one at Three Mile Island [in Middletown, Pa., on March 28, 1979] proved absolutely harmless to everybody. If somebody got frightened and moved to a different location that was about 100 feet higher in elevation, and stayed there for a year, they would have received more “excess” radiation than if they spent the year at the site boundary.
The accident at Chernobyl [in present-day Ukraine, on April 26, 1986] – which was a dual-purpose machine for producing bomb-grade plutonium while generating electricity – killed a few dozen firefighters who flew helicopters to drop cement on the reactor. The Chernobyl reactor had no containment building; the Soviets evidently thought it was easier to make more Russians than all that concrete. One thing to remember is that the Chernobyl accident was as bad as a nuclear accident can be, and the death toll per unit energy delivered by the nuclear industry was, and is, minuscule compared to that of the other energy sources.
The tsunami at Fukushima prefecture [Japan, on March 11, 2011] killed thousands of people and destroyed a lot of homes and businesses, but radiation from the reactors killed exactly nobody. The four reactors there (of which three were in operation) were not harmed by the tsunami. The damage came from the fact that the power lines connecting the reactors to the grid were knocked down, and the back-up diesel generators were in the basement and therefore flooded. Had the diesel generators been on the top floor, they would have kept humming along and kept the cooling water running. There would have been no “nuclear disaster.”
Q: What about nuclear waste? Just how dangerous is it? What would happen if it leaked into the environment?
A: When we burn coal – or wood, natural gas, oil, gasoline – the waste products flee the scene, going up the chimney or out the tailpipe. When we “burn” uranium, each atom taking part breaks up into two other atoms, but does not travel farther than a few thousand atomic diameters. These waste products (“fission fragments”), therefore, remain lodged in the uranium fuel. During an entire year of producing a billion watts of electricity around the clock, one metric ton of uranium becomes one metric ton of fission fragments. The overall weight of the fuel is around 20 metric tons, so the “waste” consists of one ton of waste and 19 tons of fuel.
The fission fragments are mostly very radioactive and very dangerous – at least for a while. To understand the relationship between half-life and radioactivity, consider this example. Suppose you have a billion atoms each of two radioactive isotopes, one of which has a half-life of 100 million years, and the other of which has a half-life of one week. During their respective half-lives, there will be a half-billion incidents of nuclear decay, with the emission of some particle or another (radiation) that has high energy. The half-billion incidents will occur over 100 million years in the one case and over one week in the other case. Obviously, you’d rather carry the sample with the 100-million-year half-life in your pocket than the one with the one-week half-life. The principle here is that the longer the half-life, the lower the radioactivity. The shorter the half-life, the higher the radioactivity. If long half-lives were a problem, then we ought to be afraid of our own oxygen, which has a half-life of infinity.
The fission fragments consist of over 200 isotopes, and they have half-lives all over the map. The ones that decay in a microsecond, a minute, an hour, a day, a month and so forth produce a lot of heat in a hurry but are so well-shielded from humanity that they pose no danger. They’re never out of the can, so to speak. The isotopes that last hundreds of millions of years have very low activity. The problems, such as they exist, are with the several-year half-lives. The most consequential ones (Sr-90 and Cs-131) have half-lives of 30 years.
Spent fuel – mostly fuel but containing a few percent of fission fragments – initially produces a lot of heat, so much so that it must be kept in cooling ponds with recirculating water. In time, the spent-fuel rods are moved into large thick-walled, stainless steel casks and placed outside. At this time, the cooling provided by air is adequate, as is the shielding provided by the stainless steel, so that people can move around the casks with no worry of being exposed to excessive radiation. A photo in Chemical and Engineering News showed a concrete pad with stainless steel casks that hold all the spent fuel – containing nuclear waste – that has been generated over decades of operation.
Workmen are free to roam amongst the casks, and anybody with a wire cutter could easily cut through the distant chain-lock fence to get in. The casks have been tested by driving them at high speed into concrete barriers, and they easily survived the collision.
Q: Do you think renewable energy sources, such as wind turbines and solar panels, are enough to offset the pollution generated by fossil fuels?
A: For running the world’s economy, solar and wind are basically worthless without backup and storage. Fossil fuels provide backup, and nothing whatsoever provides the storage at present. If, in the future, our energy came entirely from solar and wind, how much storage would be required? Five days’ worth? By way of contrast, if the units presently providing baseload power increased enough to provide average power, the storage requirements to handle intermediate and peak load would be perhaps one-quarter of one day’s energy.
Coal furnaces in homes used to be very polluting because the devices and controls required to remove junk from the smoke are prohibitively expensive for the homeowner. Large coal-fired power stations, however, can and do remove pollutants of all kinds, and emit basically nothing but H2O and CO2. Coal is not just carbon. On average, every atom of carbon is matched by one atom of hydrogen. The combustion of hydrogen is the source of the H2O. Under the right conditions of temperature and humidity, the H2O condenses into droplets called clouds. The news media make great sport of photographing those clouds backlighted by the red dawn or the red evening sky, so that the perfectly harmless H2O looks very menacing, and the text always says some garbage about carbon dioxide. Mind you, the only CO2 you have ever seen is solid CO2 – dry ice – at a temperature of -78.5ºC or colder.
Big wind “farms” – I hate the term because it does a great disservice to farmers – generate year-round average power of about 12.5 kW / ha (5 kW / acre) in excellent sites, and far less in “very good ‘sites . To provide enough year-round energy to supply a city of 700,000 with electricity requires wind turbines to be spread out over about 800 square kilometers (300 square miles) of excellent sites. Because of the vagaries of the wind, you only get about one-third of what the generator says on its nameplate.
Q: It seems that wind turbines do not have what it takes to solve the global energy problem. How do you see that problem solved in the future?
A: The energy problem we face is that of energy poverty. About 1.6 billion people worldwide have no access to electricity. Inevitably, as they rise from poverty, they will first use the cheapest energy available to them, regardless of environmental consequences. The US did the same before the 1960s. You can live with a certain amount of pollution, but you can not live without energy. As life improves, their environmental concerns will take shape, and they will move toward less pollution. The industrialized countries will be the first to go nuclear, though anti-nuclear hysteria has kept the nuclear movement in check.
Nuclear reactors provide power around the clock, but the renewables are intermittent and pretty dilute. Uranium is non-renewable, but there is enough to last until the sun expands into a red giant, and there’s even more thorium.
Q: There are many opponents and skeptics when it comes to nuclear energy proliferation. What has caused this fear?
A: Humans were introduced to gasoline by cars and trucks, to natural gas or fuel oil by the furnaces that burn them, and to electricity by light bulbs, radios and TV. Our introduction to nuclear energy were bombs. Therein lies the emotional fear of anything nuclear.
It was soon recognized that high doses of radiation cause illness, and in some cases, death. Worries about this invisible radiation – not even suspected to exist before 1890 – led to many films, not limited to “On the Beach,” about the horrors of radiation. They caught the public’s fancy, and to this day, the public remains ill-informed and frightened about the subject. To get right to the point, the cancer deaths from the bombs at Hiroshima and Nagasaki were very hard to discern among the many thousands of cancer deaths that normally occurred in the population of survivors. It took very sophisticated statistical techniques to discern the increase, which amounted to a few hundred against a background of some 20,000 normal cases, even though the surviving population had received very heavy – but sub-lethal – doses.
We live in an environment that has radiation from many sources: the potassium-40 in our bones, the uranium, radium, radon, thorium, carbon-14 and other naturally occurring radioactive materials in the soils, and cosmic radiation coming from all directions in space. The main point here is that any additional radiation coming from nuclear reactors is a tiny fraction of environmental radiation and, importantly, a tiny fraction of the variability of background radiation.
There you have it. I hope this article not only sheds light on the place that nuclear energy has in solving the global energy problem, but also shows the enormous value of dialogue between opposing sides.
Communication and information are key here; once the key points are discussed and facts, rather than emotion, are aired, I believe progress can be made.