It is, still, the energy of the future
Does nuclear energy have a future, in light of the events at Fukushima? Fukushima Daiichi is the six-unit nuclear-power station on the northeast coast of Japan that was hit by a powerful tsunami, preceded by one of the strongest earthquakes on record. The extent of the damage is considerable: The three reactors that were operating at the time of the earthquake were destroyed by the high-pressure steam produced by heat from radioactive decay and the explosive reaction of hydrogen inside the structures. The hydrogen was produced by chemical reactions between water and the protective, corrosion-resistant layer of zirconium alloy that normally seals radioactive material in a controlled location.
Those who design, build, and operate nuclear-energy facilities know that bad things can happen. They understand energy, shock absorption, chemistry, physics, and radiation, and they invest a great deal of time and effort to build facilities with layers of defense that can undergo a number of failures while still succeeding in protecting against public harm.
In a nuclear plant, the core contains the fuel materials that generate the heat that produces the steam that turns the turbines and creates massive quantities of electricity from tiny quantities of uranium. A single fuel pellet the size of the tip of my pinkie produces as much heat, when it fissions in a conventional nuclear-energy facility, as a ton of high-quality coal does when it is burned in a modern plant. When things are going right, nuclear-fuel pellets do not produce any atmospheric pollution at all, while burning a ton of coal releases between two and four tons of waste into the environment. In the U.S., we consume about a billion tons of coal each year to produce about 45 percent of our electricity.
Nuclear facilities have occasionally suffered core damage. Sometimes core damage is a result of design mistakes, sometimes it is due to actions taken or not taken by human operators, and sometimes it is caused by external forces that were not considered sufficiently probable to be factored into the design requirements. The Fukushima disaster resulted from that last risk. The facility experienced a natural disaster that was considered too improbable to require specific protective measures, but it has happened and may happen again.
The contractor teams that are bidding to clean up the facility estimate that it will require between 10 and 30 years to do the job right, depending on how “right” is defined. The recovery effort will cost tens of billions of dollars. Replacing the power capacity of Fukushima will require Japan to import an average of roughly 700 million additional cubic feet of natural gas per day. After evaluating the other nuclear plants in the country in light of the early lessons learned from the accident, the Japanese government decided to shut down the three-unit Hamaoka nuclear station located in an especially active seismic region. That decision brings the power deficit caused by the tsunami and earthquake to the equivalent of about 1.1 to 1.3 billion cubic feet of natural gas per day. Some of that deficit can be made up by the reduction in power demand that is a result of a damaged industrial infrastructure and concerted conservation efforts.
There are additional costly effects. A plume of radioactive isotopes that are either gaseous or water-soluble left the facility and spread in a northwesterly direction, contaminating areas as far as 30 miles from the plant. Everyone living within a twelve-mile radius of the plant was evacuated in the first few hours after the event, but there have been additional evacuations as radiation surveys have shown that the material moved out farther in some areas. Tens of thousands of people are still living in temporary shelters and are not sure whether they will ever be allowed to return home.
Based on the announced results of the surveys, at least part of the area that has been evacuated could safely be repopulated today, although officials are understandably cautious. Even in areas where measured radiation levels are still higher than allowable under currently accepted international standards, the levels are steadily dropping as a result of an inherent characteristic of radioactive material: It loses strength over time. A major component of the radiation level immediately after the accident was iodine-131, an isotope that loses half of its intensity every eight days and is virtually undetectable after 80 days. By the time you read this article, that period will already have passed. But for the people who have been living in gymnasiums and have had no access to personal possessions for many months, the accident has already imposed a high cost. If you add in the inevitable deterioration of unoccupied structures, there is no way to ignore the widespread nature of the effects. Some individuals or even towns may never recover from the impact of this disaster.
Given the extensiveness of the damage and the expectation of still-uncounted costs, it is legitimate to wonder whether nuclear energy is worth the risk. There are plenty of other ways to generate power, and people flourished for several thousand years before nuclear fission was even discovered. As some who are opposed to nuclear energy remind us, there are only about 435 reactors producing commercial energy today. In many places around the world, nuclear-energy-plant construction stopped several decades ago, as costs seemed to go out of control and people were repeatedly told that nuclear power involved a high level of risk.
On the other hand, it remains almost unbelievable that a few obscure minerals contain so much densely packed, emission-free energy. Every kilogram of uranium or thorium contains as much potential energy as 2 million kilograms of oil. And that relatively small number of facilities does produce the energy equivalent of about 12 million barrels of oil per day. (That is as much energy as the daily output of Saudi Arabia and Kuwait combined; the total world petroleum output is about 80 million barrels of oil per day.)
So far, our economy has focused on only a narrow selection of the available options for harnessing this energy. The majority of the nuclear reactors in operation today are large, central-station electrical-power plants that produce a steady output and use ordinary water to cool the cores, transfer the heat, and turn the turbines. Though this approach works well and has proven its safety and reliability, there are other options, which offer improvements in fuel-use rates, thermal efficiency, and power-output flexibility. Uranium dioxide pellets are not the only fuel form available; advantages might be obtained if some reactors used metal-alloy fuels, and different advantages might result from using thorium or uranium dissolved in fluoride salts.
Society will not likely turn its back on a fuel source with so much potential, although the path will not be smooth, and there will be strong opposition from competitors and from the people who seem to dislike all forms of reliable power. Whatever happens in the U.S., nuclear-energy development will not be suppressed everywhere: China announced a program to review its planned nuclear expansion in light of Fukushima, but has already concluded that there is no reason to stop or even slow down its building of nuclear plants. And developers in the U.S. are working to incorporate the lessons of Fukushima into their designs. One possibility that seems to be particularly advantageous is to build larger numbers of smaller units that have an easier time getting rid of excess heat, even when the power goes out.
Any decision to slow down nuclear-energy development needs to be taken in full understanding that nuclear fission competes almost directly with fossil fuels, not with some idealized power source that carries no risk and causes no harm to the environment. The electricity that Germany has refused to accept from seven large nuclear plants that the government ordered closed after Fukushima has not been replaced by the output of magically spinning offshore wind turbines or highly efficient solar panels. It has been replaced by burning more gas from Russia, by burning more dirty lignite in German coal plants, and by purchasing electricity generated by nuclear-energy plants in France.
People have learned to accept that burning coal, oil, and natural gas carries risks of fires, explosions, and massive spills, and causes continuous emissions of harmful fine particulates and possibly deadly gases that are altering the atmospheric chemical balance. We accept those risks because we are acutely aware of the benefits of heat and mobility.
With nuclear energy, the benefits are substantial and the risks, relative to all other reliable energy sources, are minor. Since Fukushima, there has been a remarkable void of pro-nuclear-energy advertising, which has been filled by efforts by the natural-gas industry to convince Americans that it has recently discovered a 100-year supply.
In my opinion, something close to the worst-case scenario for nuclear power happened at Fukushima. By some calculations, the earthquake and tsunami together hit Japan with a force that was equivalent to several thousand nuclear weapons. Looking at the photos of the area around the Fukushima nuclear station makes me, a career military officer, whistle with wonder at the incredibly successful attack that nature launched.
In the midst of all of the destruction, an important fact frequently gets lost: Not a single member of the plant staff or a single member of the general public has been exposed to a sufficient dose of radiation to cause any harm. The highest dose to any of the workers involved in the recovery effort has been less than 250 millisieverts (25 rem), which is beneath the internationally accepted limit for people responding to a life-threatening accident.
The doses received by the celebrated “Fukushima Fifty” recovery workers are roughly the same as the dose that the young Lt. Jimmy Carter and several hundred other people received when responding to a December 1952 accident at an experimental reactor in Chalk River, Canada. President Carter, like many others involved in that effort, is alive and apparently healthy today.
Even after the Fukushima disaster — affecting six 30-to-40-year-old plants that had primitive control systems, inadequate backup-power supplies, and insufficient protection against the potential effects of earthquakes and tsunamis — nuclear energy has compiled a remarkable safety record. It will be an important, reliable, affordable, and clean energy source for the foreseeable future.
– Mr. Adams blogs at Atomic Insights and produces the podcast The Atomic Show. He received his nuclear training as a submarine officer in the U.S. Navy and recently retired after 29 years of service.