More on Nuclear Power

Stephen DeAngelis

September 23, 2009

The Financial Times reports that “in the fight to secure fuel supplies and cut carbon emissions, nuclear power looks increasingly attractive — but is also generating concern over proliferation” [“Split on the atom,” by Ed Crooks and James Blitz, 9 September 2009]. The authors report:

“Nuclear energy provides about 15 per cent of the world’s electricity. Some 30 nations generate nuclear power; 10 to 20 are expected to join them in the next 10 years. At present there are 370 reactors in operation. The International Atomic Energy Agency, the UN watchdog, reckons that 1,400 new reactors may be built between now and 2050.”

There are two main concerns about the increasingly large number of reactors in use, being built, or planned: proliferation, as mentioned above, and nuclear waste. Proliferation is a concern because “India, Israel and Pakistan have all used the materials and technologies offered in ‘atoms for peace’ programmes to make bombs. Today the fear is that Iran is doing the same.” Grappling simultaneously with issues of reducing greenhouse emissions, controlling nuclear proliferation, and meeting energy needs will be no easy matter. Crooks and Blitz report that there are “three key factors inspiring the nuclear renaissance.”

“First, there is security of supply. Driven by the development of emerging economies such as China and India, global energy demand could rise by as much as 45 per cent by 2030, according to the International Energy Agency, which represents rich energy-consuming countries. As concerns have grown about the future availability of fossil fuels, which will be increasingly provided by a small number of large suppliers, energy consumers have come to see the virtue in diversifying their sources of supply.

“Second, there is economics. The economics of nuclear power are fiercely contested, and highly sensitive to changes in variables such as construction costs. What is unarguable, however, is that it provides an energy source not linked to the oil price.

“Finally, there is the growing pressure to meet climate change goals. The US and its allies accept that the global struggle to cap greenhouse gas emissions means nuclear energy options must be available. Nuclear energy is almost free of emissions and, if growing energy consumption is not to lead to soaring concentrations of carbon dioxide in the atmosphere, it is likely to play an increasingly important role.”

The authors point out that the growing global trend of taxing greenhouse emissions will also spur countries toward nuclear power. Some critics believe that a resurgence in nuclear power comes too late, offers too little and is both dangerous and expensive. Crooks’ and Blitz’ main concern, however, is proliferation.

“The most serious concern of all over the nuclear renaissance remains the link to proliferation. Power stations are not, in themselves, much of a risk – the problems lie in the uranium enrichment process, which can be employed to develop both civil and military versions of nuclear power. ‘The world will be a much more dangerous place if more countries acquire enrichment and reprocessing facilities, because then we will have more potential nuclear weapons states,’ says Leonor Tomero, of the Center for Arms Control and Non-Proliferation in Washington.”

As I discussed in a recent post entitled The Future of Thorium, thorium-fueled reactors could help address proliferation concerns because they do not generate weapons-usable plutonium in the reaction; they consume any weapons-usable uranium isotopes produced in the process; and they leave comparatively little waste and even that waste is less radioactive. Aside from those benefits, thorium-fueled reactors could help destroy excess plutonium from countries that built the stockpiles in the first place, actually reducing the world’s nuclear threat. With the possibility of over 1,000 reactors being built over the next 40 years, alternatives to current reactor designs needs to be seriously considered. Countries interested in developing nuclear weapons, however, will continue to insist on developing nuclear fuel capabilities as well (meaning the ability to enrich uranium). The argument they will use is that they don’t want to be dependent on a supplier of nuclear fuel any more than they want to be dependent on a supplier of coal, natural gas, or oil. Countries like the UAE, however, have indicated that are open to buying nuclear fuel from an outside supplier. The attached image depicts the typical nuclear fuel cycle (click to enlarge).

Nuclear fuel cycle

One may ask why oil-rich nations are interested in nuclear power anyway. The answer is simple — economics.

“Even for oil- and gas-rich countries, such as Iran and the UAE, another Middle Eastern country keen to build civil reactors, nuclear generation makes sense because it frees up more of their hydrocarbon resources for export. The earnings from those exports ‘would easily pay for investment in nuclear energy’, says Hans-Holger Rogner of the IAEA. Given likely long-term oil and gas prices, ‘It makes economic sense.'”

The bottom line for Crooks and Blitz is that nuclear proliferation is likely to remain a concern in the decades ahead. Such concerns, however, are not likely to staunch the desire of many countries to build nuclear reactors. Jim Rogers, chairman, president and chief executive officer of Duke Energy Corporation which operates nuclear power plants in the U.S., is, of course, a strong believer in the future of nuclear energy “Why Nuclear Power Is Part of Our Future,” Wall Street Journal, 4 August 2009]. He writes:

“According to industry estimates, building a new nuclear plant can result in the creation of 1,400 to 1,800 jobs during construction, with peak employment as high as 2,400 jobs. Operating a new plant can generate 400 to 700 permanent jobs that can pay almost 40% more than average local salaries. These are good, long-term jobs—the kind you can raise a family on. Additionally, each year the average nuclear plant generates approximately $430 million in sales of goods and services in the local community and nearly $40 million in total labor income, including both direct and secondary economic impacts. Imagine the economic stimulus if the 26 or so new nuclear plants currently planned for the U.S. were fully developed. … When it comes to creating thousands of 21st century jobs—energy jobs on which we can rebuild the middle class—nuclear power clearly has the edge.”

Roger’s is, not surprisingly, a cheerleader for an industry that has taken its lumps. As a result, nuclear power has basically been on hold in America for decades. Even though the U.S. currently has the largest number of nuclear reactors in operation, France has long been seen as nuclear power’s strongest proponent. The Economist openly asks, “Will France continue to lead the global revival of nuclear power?” [“Power struggle,” 6 December 2008 print issue]. It continues:

“With ‘no oil, no gas, no coal and no choice’, France decided to go nuclear in 1974, and today about 80% of its electricity is generated by 59 nuclear plants across the country. But even France became pessimistic about nuclear power: it stopped building new reactors at the end of the 1980s and in 2002 a government report called the industry a ‘monster without a future’. How things have changed. Nuclear power is back in favour, thanks to fears about oil supplies, energy security and global warming. France is poised to develop its expertise into a significant export. Its president, Nicolas Sarkozy, considers the sale of nuclear power to be central to his diplomacy: it is a badge of France’s technical prowess and a reaffirmation of its status as a global industrial power.”

Areva, a government-owned French company, is currently building three nuclear power plants around the world and The Economist believes that the company’s “‘third generation’ reactor design, called the EPR, [has] an edge over blueprints from its two big rivals: Westinghouse, now a unit of Toshiba of Japan, and GE Hitachi, a recently formed joint venture.” Rebecca Smith writes about third and fourth generation reactor designs [“The New Nukes,” Wall Street Journal, 8 September 2009]. She begins with Westinghouse’s third-generation design.

“The Westinghouse AP1000 boasts half as many safety-related valves, one-third fewer pumps and only one-fifth as much safety-related piping as earlier plants from Westinghouse, majority owned by Toshiba Corp. In an emergency, the reactor … is designed to shut down automatically and stay within a safe temperature range. The reactor’s passive designs take advantage of laws of nature, such as the pull of gravity. So, for example, emergency coolant is kept at a higher elevation than the reactor pressure vessel. If sensors detect a dangerously low level of coolant in the reactor core, valves open and coolant floods the reactor core. In older reactors, emergency flooding comes from a network of pumps—which require redundant systems and backup sources of power—and may also require operator action. Another big concern is how well a plant can handle a terrorist attack, especially the nightmare scenario of someone flying a jetliner into the reactor area. The Evolutionary Power Reactor from France’s Areva SA, another Generation III design, guards against such an accident by putting the reactor inside a double containment building, which would shield the reactor vessel even if the outer shell were penetrated. The design also boasts four active and passive safety systems—twice the number in many reactors today—that could shut it down and keep the core cool in case of a mishap. … The Union of Concerned Scientists, a group critical of nuclear expansion, considers this the only design that is less vulnerable to a serious accident than today’s operating reactors. Further out, Gen IV reactors, which use different fuels and coolants than Generation II and Generation III reactors, are designed to absorb excess heat better through greater coolant volume, better circulation and bigger containment structures. Advanced research into metal alloys that are resistant to cracking and corrosion should result in more suitable materials being used in plants, too, and giving them longer useful lives. Still, Generation III reactors are incredibly complex systems, requiring the highest-quality materials, monitoring and training of personnel. Critics say it’s unrealistic to think they can operate flawlessly. Corrosion of vital equipment remains a potential problem, especially if it goes undetected deep within parts of the reactor that are difficult or impossible to directly inspect. What’s more, none of the Generation III designs have been cleared for construction by the Nuclear Regulatory Commission. Some Generation IV concepts haven’t even been presented to the NRC for review, and they still are years away from crossing that threshold.”

Smith then discusses pebble bed reactors, which I first talked about in 2006 in a post entitled The Future of Nuclear Power. She writes:

“Some researchers see the answer to the safety problem in revolutionary reactor designs that promise to be more ‘inherently safe’—physically incapable of suffering a catastrophic meltdown. One such design, at least in theory, is the Pebble Bed Modular Reactor, being developed in China and South Africa. It’s powered with balls of uranium-filled graphite rather than the typical fuel rods. If the cooling system were to fail, the reactor temperature stays well below the balls’ melting point and then automatically cools down.”

The Economist admits that “the high cost of building new plants, and the uncertainty over the cost of nuclear energy relative to other sources, could delay the nuclear renaissance, especially in the midst of a credit crunch. Luckily for vendors, governments are bent on tackling climate change and securing energy supplies, and are likely to offer big subsidies.” Smith agrees that high costs have crippled the nuclear industry in the past which is why some companies are looking at building smaller reactors that cost less. She reports:

“Some see nuclear power’s future in small reactors that could be manufactured in factories instead of on site—and cost only $3,500 to $5,000 per kilowatt of capacity [as opposed to $4,000 to $6,700 per kilowatt of capacity for larger reactors], or millions of dollars instead of billions. Babcock & Wilcox, a unit of McDermott International, has designed a small 125-megawatt reactor that would be built at its U.S. factories and then delivered to power-plant sites by rail or barge. This would eliminate a bottleneck—and the associated higher costs—for ultra-heavy forgings that are required for large reactors. … Another plus of small reactors: They’re designed to be refueled less frequently, reducing the number of refueling outages. Instead of every 18 months to two years, they could go four or five years, reaping a saving from having less down time. Another feature of some reactors is the ability to do more maintenance while plants are running, again reducing idle time.”

All of the proposed designs have their critics, Smith reports. And all of them produce radioactive waste — the prime concern of environmentalists. As Smith writes, “one of the most contentious issues surrounding nuclear power: Where do you put the spent fuel?” She continues:

“Tens of thousands of metric tons of nuclear waste—mainly spent fuel rods—are sitting at power-plant sites while the federal government struggles to come up with a site to store it all. No nation has yet built a permanent waste site, although the current situation can continue for some time: Even critics say storage methods in place now should allow fuel to be stored safety for 50 to 100 years, while permanent plans are worked out. The big problem with controlling waste: Today’s reactors capture only about 5% of the useful energy contained in uranium—which means lots of radioactive leftovers once the fuel is used. Some Generation III reactors promise to address this problem by squeezing more electricity out of their fuel, reducing the total amount of waste produced, but it’s only by a relatively small amount. In short, it does nothing to solve the looming waste issue, though it does produce more megawatts of electricity in the short run. Some Generation IV reactors, known as fast reactors, may offer a breakthrough in the future—because they’re designed to burn previously used fuel. GE-Hitachi, for example, is developing a fast reactor called Prism that would take spent fuel or weapons waste, sitting in storage today, and use nearly all of it as fuel, leaving little waste. What’s left would also be less radioactive than current waste, and would need to be stored for hundreds of years instead of thousands of years, scientists say. Fast reactors are able to unlock energy in waste because they can burn plutonium, neptunium and other materials that Generation II and Generation III reactors leave behind. GE-Hitachi estimates there’s enough energy sitting in nuclear storage sites in the U.S. to completely meet the nation’s energy needs for 70 years, if fast reactors were used to convert waste into electricity.”

Even fast reactors have their critics and skeptics. The Economist reports, however, that “plastic beads may provide a way to mop up radiation in nuclear power-stations and reduce the amount of radioactive waste” [“Trappings of waste,” 5 September 2009 print issue]. After discussing the challenge of nuclear waste water, the article reports:

“A team of researchers led by Börje Sellergren of the University of Dortmund in Germany, and Sevilimedu Narasimhan of the Bhabha Atomic Research Centre in Kalpakkam, India, think they have found a new way to deal with it. Their solution is to mop up the radioactivity in the water with plastic. In a pressurised-water reactor, hot water circulates at high pressure through steel piping, dissolving metal ions from the walls of the pipes. When the water is pumped through the reactor’s core, these ions are bombarded by neutrons and some of them become radioactive. The ions then either settle back into the walls of the pipes, making the pipes themselves radioactive, or continue to circulate, making the water radioactive. Either way, a waste-disposal problem is created. Because the pipes are steel, most of the ions are iron. When the commonest isotope of iron (56Fe) absorbs a neutron, the result is not radioactive. The steel used in the pipes, however, is usually alloyed with cobalt to make it stronger. When common cobalt (59Co) absorbs a neutron the result is 60Co, which is radioactive and has a half-life of more than five years. At present, nuclear engineers clean cobalt from the system by trapping it in what are known as ion-exchange resins. These swap bits of themselves for ions in the water flowing over them. Unfortunately, the ion-exchange technique traps many more non-radioactive iron ions than radioactive cobalt ones. To overcome that problem Drs Sellergren and Narasimhan have developed a polymer that binds to cobalt while ignoring iron. They made the material using a technique called molecular imprinting, which involves making the polymer in the presence of cobalt ions, and then extracting those ions by dissolving them in hydrochloric acid. The resulting cobalt-sized holes tend to trap any cobalt ions that blunder into them, with the result that a small amount of the polymer can mop up a lot of radioactive cobalt.”

The Holy Grail of nuclear power is fusion reactors that leave no radioactive waste, but no such reactors are on the horizon. There is, of course, the matter of “table top” or “cold” fusion that The Economist calls “the beast that will not die.” [“The beast that will not die,” 28 March 2009]. They report:

“On March 23rd, 20 years to the day since Martin Fleischmann and Stanley Pons announced that they had accomplished nuclear fusion at room temperature in apparatus built on a laboratory bench (they hadn’t), experimental results purporting to demonstrate such cold fusion were presented to a meeting of the American Chemical Society in Salt Lake City, Utah. Cold fusion is so called to distinguish it from the sort that goes on in stars and hydrogen bombs. That needs a temperature of several million degrees. If cold fusion worked, it could provide an inexhaustible supply of clean energy. But it has been cold-shouldered by most scientists. Funding has dried up. What research there is, is conducted outside mainstream laboratories. In fact, its advocates have renamed their endeavours “low-energy nuclear reactions” because cold fusion has received such a drubbing. That is because most scientists think it impossible. … To try to persuade their fellow researchers of the reality of cold fusion, Pamela Boss and her colleagues decided to search for evidence of the presence of high-energy neutrons, which should be produced when two nuclei fuse. Dr Boss works for the Space and Naval Warfare Systems Centre in San Diego, California, an organisation that develops communication systems for the American navy. The experiment that she thinks results in cold fusion uses an electrochemical technique in which two electrodes are plunged into an electrolyte made from a recipe that includes heavy water. Heavy water gets its name because it contains deuterium, a form of hydrogen that has a neutron in its nucleus as well as the usual proton and thus weighs twice as much as the ordinary sort. Deuterium is easier to fuse than simple hydrogen, and so is favoured in these sorts of experiments. Dr Boss and her colleagues reported that one of the electrodes in their experiment got hot, an effect they attribute to fusion. Most researchers in the field, though, do not accept that heat is sufficient evidence of fusion (if only because it was the basis of the Pons/Fleischmann claim). So to strengthen her case, Dr Boss placed a special plastic called CR-39 next to the hot electrode. If fusion was taking place, then neutrons flying through the plastic would cause protons within the material to recoil, leaving telltale tracks. Studying CR-39 under a microscope and counting the number of tracks is a standard way to assess how many neutrons bowled past. Dr Boss and her colleagues reckon they have seen enough tracks to provide evidence for the emergence of high-energy neutrons from their experiment. They published the results earlier this year in Naturwissenschaften. Dr Boss told the meeting, ‘taking all the data together, we have compelling evidence that nuclear reactions are stimulated by electrochemical processes.’ Certainly there would appear to be something strange going on. But even if Dr Boss’s results really are evidence of high-energy neutrons, many physicists will continue to deny that cold fusion could be real. That is because there is no theoretical explanation for electrochemical cold fusion within the existing laws of physics.”

All I can say is stayed tuned but don’t hold your breath. The real point is that there are no silver bullets when it comes to nuclear energy. It continues to offer a promising way to reduce greenhouse gas emissions but raises environmental challenges associated with its waste. And, of course, there are the proliferations issues discussed earlier by Crooks and Blitz. I believe nuclear power does play an important role in the world’s global energy future, but it’s only a piece of the energy puzzle.