The Human Condition:

No to Nukes! – February 17, 2019

Diablo Canyon Nuclear Power Plant

Although I would like to see this country and the world transition from fossil fuels for electric generation,1 I am no fan of nuclear power. I say this as a technical writer and communicator who worked for six years at an engineering and construction company that built large-scale power generation, including two nuclear plants, and then at a public utility that built two units of nuclear generation along the California coast. I supported those efforts with my writing skills but, all the time, I was not a “believer” in nuclear power.

The first large-scale, commercial nuclear power plant in the United States was the Shippingport Atomic Power Station in Pennsylvania. It started operating—or “reached criticality”—in 1957. In the years that followed, and with the support of the Atomic Energy Commission under the rubric that atomic energy in the hands of local utilities would be “too cheap to meter,” more than ninety reactors were installed and brought to power in this country. Usually, two or three reactors would be placed at one site by a utility, to effect economies of scale.

Oddly, this burst of nuclear activity lasted less than twenty years. No ground has been broken on new nuclear plants after 1977, except for four reactors in the current decade at two existing plants which have been licensed by the Nuclear Regulatory Commission to start construction and have not yet been completed. Only one reactor has entered commercial operation since 1996.2

What happened? This dearth of plants in a promising new technology occurred two years before the accident at Three Mile Island. And while the beginning of this falloff in construction was roughly simultaneous with President Carter’s executive order in April 1977, which banned the reprocessing of spent nuclear fuel, building a “nuke”—as the utility business calls these plants—is a long-term endeavor. It usually takes ten to fifteen years from the initial planning stages and application for a license to begin construction until the reactor finally fires up. Nothing that happened in April of that year would have caused this process at so many utilities to stop on a dime.

I happen to remember the reason. My father was a long-time subscriber to Fortune magazine, and I had access to his copies as a young reader. In 1968, while I was still in college, I read an article that laid out the truth behind the “too cheap to meter” claim. A decade later, when I was a communicator at the engineering company, I helped write a similar article for our business development magazine. Here is the story.

The nuclear fuel cycle begins with uranium ore in the ground. That ore has to be dug out, transported to a processing plant, and refined into an intermediate material, uranium oxide, which is called “yellowcake” because it looks just like Duncan Hines cake mix. The chemical formula is U3O8. Mining, transporting, and processing take a lot of energy, usually in the form of fossil fuels.

Uranium is radioactive because its top-heavy atom exists in a number of isotopes. The most common form, accounting for 99% of ore, is U-238—referring to the number of protons in the nucleus that define the element plus the neutrons that provide the final atomic weight of this particular isotope. U-238 is the most stable form. The least stable—that is, most likely to have its nucleus split apart and create some fun—is U-235. A bunch of uranium ore or a block of metal out of the ground is going to kick off the occasional fast neutron or other bit of radiation, which makes it relatively unsafe to be around, but it’s not going to explode or melt down or anything. To make the kind of uranium that will work in a reactor, or a bomb, you have to enrich it by bumping up the percentage of U-235. To do this, you chemically change it into a heavy gas, uranium hexafluoride (UF6), and spin it in a centrifuge to separate the lighter U-235 from the heavier U-238. Spinning those centrifuges takes a lot of energy, usually in the form of electricity.

Once you have the isotopes separated, you can then blend your mix of U-238 to U-235 for either making reactor fuel rods or bomb parts. You want a mixture, not just the pure U-235, for various reasons. First, the most reactive isotope in its pure state is going to be terribly unstable, not good to handle, and won’t last long. Second, your fuel rod makes use of the more stable U-238, because when its nucleus gets hit by a fast neutron from the naturally decaying U-235, it will also tend to split and release heat. And sometimes, instead, the U-238 absorbs that neutron and become plutonium-239, which will eventually decay on its own.

Once you have your mixture, you form the uranium metal into pellets, encapsulate them in a long, cylindrical clay matrix, and clad that matrix in stainless steel. When you have enough rods, you bundle them into a fuel element that is designed, by content and configuration, for a particular type of reactor. After you load the reactor with fresh rod bundles and add a moderator—in the Westinghouse reactors I’m familiar with, it’s boron in the water, which slows the fast neutrons from decaying uranium atoms just enough for them to profitably impact other uranium atoms—you get criticality and a chain reaction. It’s this chain reaction that produces useful amounts of heat to boil the water that drives the power station’s turbine. The reaction also creates byproducts in the pellets, like isotopes of strontium and cesium from the split uranium atoms, and the occasional plutonium atom.

After about eighteen months in the reactor running at full capacity, the percentage U-235 is depleted, the remaining U-238 can’t be induced to split, and the pellets have a high concentration of those unpleasant strontium, cesium, and other isotopes that aren’t good for the reaction. You now have spent fuel waste. If you don’t do something productive with it—and we’ll get to that in a moment—you have to keep the rods cool, because the spent fuel is still radioactively and thermally hot. And you have to watch over them for about 10,000 years.

The reason most utilities have given up on nuclear power is simple: the energy cost of mining, processing, concentrating, and fabricating those fuel rods—think of diesel fuel, trucking, chemical processes, and electrically powered centrifuges loaded with heavy gas—is greater than the energy produced by “burning” the rods in a reactor. Nuclear power becomes a net drain on your energy economy. It might be more convenient to burn those rods in a reactor sited along a scenic coastline than to build a coal plant there and have to deal with railcars, coal piles, stack gas, fly ash, and a long plume of carbon dioxide wafting over the nearby valley. But you’re still running at an energy deficit. That was the point of the Fortune article: nuclear power is a way for your energy economy to go broke slowly.

There are people who can make nuclear power work. France and Japan depend on it. In 1987, at a conference sponsored by Energy Daily, I heard the head of Électricité de France S.A. explain how. He noted that the national utility draws about 64% of its power from nuclear because, as he said, “France has no coal. France has no oil. France has no choice.” Unlike the United States, where local utilities run a hodgepodge of reactor makes and designs—Westinghouse, Brown & Root, boiling water reactor, pressurized water reactor, etc.—France installs one design only. And when the nuclear fuel is spent and it’s time to open up the reactor vessel and replace the rod bundles—along with fixing anything else that’s broken in the plant during this downtime—the local operators don’t have to suddenly become reactor maintenance specialists. Instead, EDF sends a flying team of refueling specialists to the plant to break it down and reload the core. And then EDF takes the spent rods and reprocesses them. EDF also takes the spent fuel from Japanese reactors and reprocesses it at a profit.

Reprocessing closes the nuclear fuel cycle. The rods are broken apart and the steel and clay discarded as low-level radioactive waste. The pellets are chemically processed to separate the remaining U-238 and valuable Pu-239 for reuse, while the cesium, strontium, and other isotopes are mixed with molten glass to form pellets of high-level waste that can be more easily cooled and stored. Then fresh amounts of U-235 are added to the fuel mix and new pellets, rods, and bundles are fabricated. By reusing most of the fuel over and over again, nuclear power becomes a net energy producer instead of an energy drain.

But Jimmy Carter banned this reprocessing in the United States and closed down the sites where it could be done out of fear of creating a “plutonium economy” and enabling worldwide nuclear terrorism. We’ve also been slow—to nonexistent—about moving and processing spent fuel from our commercial reactors for long-term underground storage. So each nuclear utility must hold, cool, and watch its growing inventory of spent fuel bundles for an indefinite period of time.

Perhaps there are other forms of reactor that don’t have these problems. One hears promising things about thorium—which is transmuted into U-233 for the nuclear reaction. And physicists have been trying for thirty years to create usable fusion reactions with magnetic containment and laser ignition, but these fusion experiments still haven’t produced more energy than they consume, and the promise of fusion has always been—and still is—“ten years away.”

So it wasn’t the inherent dangers, public reaction, activist agitation, government regulation, or any event at places like Three Mile Island or Fukushima that killed nuclear power in this country. That blow was struck years earlier, when utilities began to discover that for all its clean, efficient, modern, science-fiction-sounding promises, nuclear power just isn’t very efficient and never was “too cheap to meter.” And as the efficiency of turbine technology has improved over the last thirty years, largely due to advances with jet engines, spinning a generator with the heat of a natural-gas flame—essentially putting a jet engine and a generator on a flatbed truck—has become competitive with a huge, cantankerous, steam-powered, baseload generating station.

I wish it weren’t so. I wish we could push banana peels into a household appliance like “Mr. Fusion” and power a flying car that also travels in time. But so far … not.

1. And it’s not because of the industry’s “carbon footprint” and the prospect of anthropogenic global warming. Sure, the United States has enough coal to power our society for a thousand years, but it’s still a limited resource in the larger scale of things and a pesky resource to find and use cleanly. Our other fossil choices, oil and gas, are more limited than our coal resources and far more valuable as chemical feedstocks than as fuel in a generating plant. And when I say “larger scale,” I’m thinking two or three thousand years ahead.
    Energy is the stuff of civilized human life: it has been so since the first cave man burned a stick of wood for light and warmth. Eventually, we will have to find a more efficient, cleaner, renewable source of electric power than carbon-based fuels. Wind and solar are too diffuse for reliable, large-scale energy generation. So we might as well start looking for the as-yet undiscovered—and at this point largely theoretical and magical—technology that will power us in the long run. And fission-based nuclear is not that.

2. For a short history of nuclear power in this country, see this Wikipedia entry.