"Nuclear" Shouldn't Frighten You

To fight climate change, we need this power source. Still uneasy? Here's what you ought to know.

Many experts believe that the world cannot approach zero-carbon emissions without the widespread use of nuclear power. Yet many in the public dread a nuclear accident or a terrorist attack on a reactor. How serious are these dangers?

First, some good news: A nuclear explosion using a power plant is impossible. The fuel is not enriched nearly enough to produce the required energy. The accidents at Chernobyl in 1986 and Fukushima in 2011 were not nuclear blasts, but chemical fires or explosions caused by steam or hydrogen gas. The risk in an accident comes from direct radiation and radioactive fallout. Let’s look at those separately.

Direct Radiation

Several hundred nuclear reactors exist for research and medical purposes, as well as 440 commercial power reactors and an untold number powering ships. All emit radiation, but shielding protects the tens of thousands of people who work around those reactors. Years after Fukushima, the Japanese government had attributed only one death to radiation. The only certain cases of serious radiation poisoning from a reactor were in the Chernobyl disaster, the worst nuclear accident in history. But those Soviet reactors were badly designed, shoddily built, lacked proper safety shielding, and the operators did everything wrong. The steam explosion ejected huge quantities of radioactive material into the atmosphere, yet the only deaths from direct radiation were about 60 people working at the site. Modern designs are far safer. Even with poor design and no shielding, direct radiation from a disaster would only affect those very near (i.e. plant workers). The reason is that radiation loses potency by the square of the distance it travels: The intensity at 200 yards is one-quarter of that at 100 yards. In short, direct radiation is not a serious hazard beyond the reactor proper. An explosion at a chemical factory or a fire at an oil refinery is a vastly greater danger.

Indirect Radiation (radioactive fallout)

Chernobyl spewed massive quantities of radioactive particles into the air, and the wind carried those particles over much of Europe. Although most of the radiation from that fallout was at levels below natural background radiation, some predicted up to a million deaths from cancers. Nearly 35 years later, we know that no such tragedy came to pass. The percentage increase of fallout-induced cancers has been so small that there is no clear, measurable increase in cancer rates with one exception, treatable thyroid cases. Studies show about 20,000 such cases in Ukraine, Belarus and parts of Russia, caused by iodine-deficient children drinking milk contaminated with radioactive iodine. Most of these cases could have been prevented had the Soviets distributed iodine tablets. For perspective, these health effects are orders of magnitude less than the harm from the Bhopal chemical leak of 1984, which killed at least 18,000 people and permanently disabled an additional 50,000. The groundwater in the area is still undrinkable today.

The Terrorism Threat

So far as we know, there have been no successful terrorist attacks on any of the world’s thousand or so reactors. This is probably for good reason. While they could knock one offline or force a shutdown, all that would do is shut off power. It would be much easier to attack a conventional or renewable power system.

Terrorists might attempt to provoke a meltdown, but would need incredible skills to achieve this. And the worst that would happen to a modern water-cooled reactor would be another Fukushima. Another famous case, Three Mile Island—the Pennsylvania accident in 1979 that terrified the American public—has been studied intensely, finding no observable health effects.

A further common fear is that terrorists could steal radioactive material. In a power reactor, the radioactive material is the fuel rods. Could these make a dirty bomb to spread radioactive fallout? Not really. The cost and effort would be prohibitive. Fuel rods, especially spent ones, are so hot that direct radiation would kill anyone who came close. They cannot be safely removed from their non-portable protections except by equipment that is big, cumbersome and expensive. Terrorists could more easily deploy chemical or biological agents.

Finally, could spent rods be used to make an atomic bomb? It would be almost impossibly difficult. The technical and physical difficulty of extracting plutonium from spent rods requires the resources of a good-sized country. In the 1940s and early ’50s, the United States did use spent fuel as a source for bomb material. But it required such massive equipment and cost that the government soon switched to other sources. North Korea made bomb material without a power reactor, and Iran chose direct enrichment rather than trying to use its nuclear power plant.

So even if terrorists somehow did get control of a nuclear power plant, there is no opportunity to cause widespread harm. Modern plants are even designed to sustain an airplane crash without causing harm beyond the plant itself.


The next generation of advanced reactors due out later this decade will have even fewer vulnerabilities than today’s pressurized water-cooled reactors. Almost all advanced designs use no water and are “walk-away-safe,” which means that no operator or mechanical intervention is necessary to ensure safety. The physics of the fuel automatically stop the reaction if it gets too hot, and most designs cannot create radioactive fallout.

Even better, some small designs operate automatically, requiring no operator: They can be buried in the ground and just hum along generating energy for 10, 20 years or more. Advanced reactors promise an almost unlimited availability of clean heat and power, inherently safe, dispersible, and reliable 24/7, regardless of the weather.

Some environmental campaigners still insist on a decades-old horror of reactors that traces back to a justified hatred of nuclear bombs. But that has never been warranted for energy plants. If they—and all of us—are to find a way out of our climate crisis, we must recognize that we already have a large part of the solution.

W. D. Budinger, who studied at Sandia National Laboratories and Los Alamos National Lab, is an inventor with three dozen patents. He spent more than 30 years as chief executive of Rodel Inc., a global manufacturer of semiconductor materials.