Radioactivity Neutralization Methods
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Reprocessing and Transmutation of High-Level Nuclear Waste Composition of reprocessing wastes per 1,000 kg of spent nuclear fuel: (Murray, 2003) Fission products 28.8 kg U 4.8 Pu 0.04 Np 0.48 Am 0.14 Cm 0.04 Reprocessing chemicals 68.5 Reprocessing wastes The weight of reprocessing waste is about one-tenth of the weight of spent nuclear fuel. Sr-90 and Cs-137 are the major problems during the first few centuries of waste storage. Can they be eliminated from high-level waste? This will be discussed later. For now by definition, reprocessing wastes are high-level waste. Reprocessing wastes include aqueous/nitric acid solutions that contain fission products such as Cs, Sr, Zr, Ni, La and others which are derived from spent nuclear fuel from military applications in the US. Because the US does not reprocess spent nuclear fuel, high-level waste treatment research has not been a major priority in the US. In general, these are high-level liquid wastes that are stored in underground tanks. https://wiki.engr.illinois.edu/download/attachments/194283148/Waste+treatment.pdf?version=1&modificationDate=1330551702000 is a colorfully illustrated primer on radioactive waste treatment. It includes more on calcination, immobilizing, vitrifying and synthetic rocks. Once high-level waste is fixed into some type of wasteform, it may still leach into water of various temperatures, acidity or alkalinity, and with enough time. Basic concepts of transmutation Transmutation is defined as transformation of one isotope into another by neutron absorption. The products are either the next heavier isotope or two or more fission products. Fissile is defined as fissionable by thermal neutrons. 235U is fissile whereas 238U is not. Energy production results in transmutation 235U + η → 236U* → fission products + η + β + γ The fission products include 90Sr with a half-life of 28.8 years and 137Cs with a half-life of 30.1 years. And by neutron capture 238U + η → 239U* → 239Np + β- → 239Pu + β- ( 23.5 min) (2.35 d) (24,400 y) Transmutation as a curse and cure? Transmutation creates waste management issues with respect to either once-through spent nuclear fuel or in reprocessing spent nuclear fuel. Can transmutation be applied to spent nuclear fuel to reduce its radiotoxicity by converting radionuclides with long half-lives to ones that decay more quickly? The Roy Process Some people think so. Several transmutation processes have been proposed. Take for example “The Roy Process.” In 1979, the late Dr. Radha Roy announced he “had invented a new method to render all radioactive waste elements, including plutonium, into non-radioactive elements.” “With the Roy Process, high-level nuclear waste can be neutralized and totally eliminated at each reactor site, where the waste is now stored in cooling ponds. When treated with the Roy Process, these unstable radioactive isotopes rapidly decay into stable, non-radioactive elements . . .” From: http://www.lightparty.com/Energy/RoyProcess.html http://www.youtube.com/watch?v=vEyMUBBGePQ Realities of Transmutation as a Waste-Treatment Technology Transmutation of persistent fission products: 99Tc + η → 100Tc → 100Ru (2.12 x 105 y) (16 sec) (Stable) 129I + η → 130mI → 130I → 130Xe (1.6 x 107 y) (9 min) (12 hours) (Stable) These are examples of desirable reactions. The process of transmutation can also initiate undesirable side reactions that produce new radionuclides with long half-lives. For example, 133Cs + η → 135Cs (stable) (2.3 x 106 y) 241Pu + η → 242Pu (13.2 y) (389,000 y) 35Cl + η → 36Cl (stable) (3.1 x 105 y) Some fission and activation products do not transmute significantly because their cross section for capturing thermal neutrons is too small. The term “cross section” is the probability of a nuclear reaction resulting in transmutation. Some of these products include 79Se, 126Sn, 36Cl, and 14C. This also includes 90Sr (1.34 barns) and 137Cs (0.176 barns). Transmutation cannot be applied to solid spent nuclear fuel. Because spent nuclear fuel contains 235U and 238U, the addition of thermal or fast neutrons would produce more Pu which is not the goal. Transmutation must be coupled with chemical separation of the radionuclides into different wastes streams. Separation and Transmutation Under study: Aqueous chemical separation (PUREX, UREX, TRUEX, etc.) followed by transmutation in light water reactors or fast breeder reactors. Pyroprocessing separation followed by transmutation in light water reactors of fast breeder reactors. Current research results “SNF is placed into a cathode basket that is then immersed in a pool of molten LiCl-Li2O. When a sufficiently high electrical potential is applied, oxygen gas bubbles are evolved at the anode, and actinide oxides are reduced to metals at the cathode. Rare earth fission products appear to remain unreduced in the basket. Alkali and alkaline earth fission products (Cs, Sr, Rb, and Ba) partition into the salt, presumably as chlorides.” (Simpson, 2006) Still have waste issues . . . 
Pyroprocessing “The accumulation of these alkali and alkaline earth fission products in the salt will require periodic disposal of the salt into a waste form that can be safely stored for approximately 200 years to allow decay of the 137Cs and 90Sr. Salt can be simply removed from the process once it reaches a contamination limit, blended with zeolite, and formed into a ceramic waste.” (Simpson, 2006). Barriers to Separation and Transmutation Separation requirements for transmutation: U and Pu must be separated (PUREX). Cs and Sr must be separated (under study). Methods for separating Am, Cm, Np, and turning them into targets for transmutation are still at the experimental stage.
All extractions need to be optimized to extract nearly all of each radionuclide. Any separation and transmutation approach would increase the volume of low-level radioactive waste. What is the best source of neutrons for separation and transmutation? Light-water reactors? Fast reactors? Breeder reactors? Coupled with accelerators? Accelerator Transmutation of Waste? Generation IV reactors? Source: https://wiki.engr.illinois.edu/download/attachments/194283148/Waste+treatment.pdf?version=1&modificationDate=1330551702000 is a colorfully illustrated primer on radioactive waste treatment. Its topics include: Composition of spent nuclear fuel and reprocessed nuclear waste. High-level liquid radioactive waste. French vitrification program. Ceramic wasteforms – ‘synthetic rock’. Realities of transmutation of radioactive waste.
George Wiseman, Oroville, Washington, USA www.eagle-research.com Source: “130 Electrical Energy Innovations” www.padrak.com/vesperman Below is the text of Ken Rauen’s December 5, 2013 email to Gary Vesperman. Rauen's Rauen cycle and Superclassical cycle engines expand working fluids with environmental heat to provide useful net mechanical power. Hi Gary, I like the air well idea. When energy to make electricity is free, heat pumps can refrigerate the atmosphere and condense water from low humidity air easily, an air well. You may want to know that my current work in environmentally heated engines are two projects being promoted by Mark Goldes' group, Aesop Institute. See www.aesopinstitute.org. The home page says something about the piston engine, and the topics on top refer to the piston engine as one project and the turbine engine as the other project. In both cases, other men invented these engine concepts. I just took the ideas to a better design, understanding how they work. One patent application has been made for Wainwright's piston engine concept, and the Kondrashov turbine idea has spawned another related invention. Our potential investors are not delivering much yet – survival money – and we are still looking for more support. Your exposure of this work could be helpful. Unlike other free energy possibilities, I can go "nose to nose" with any university physics professor about the science behind these projects. The science is solid. The technology is identified. It just needs resources to acquire facilities, tools, and materials. Have Fun,
Ken Rauen Capacitive Step-Down Transformer The capacitive step-down transformer is a simpler, cheaper, lighter, smaller, nearly 100% efficient alternative to inductive transformers. Capacitive step-down transformers do not have the inductive, noise, heat and sound losses of inductive transformers. Capacitive step-down transformers can be used anywhere that is stepping down high voltages, low amperes into lower voltages, higher amperes – industry, commercial, residential and appliances. Not using capacitive step-down transformers has resulted in lower efficiency of transmission and distribution with enormous waste of electricity. Capacitive power supplies (CPS) are inherently capacitive amperage limiting. So therefore short circuits do not damage them. A brownout or blackout in one area of the grid will not take down any generators that are protected with CPS technology. There is no need for electronic controls or a grid infrastructure upgrade – the amperage control is automatic and instantaneous. If a solar flare blows out many inductive transformers, capacitive step-down transformers can be fast, effective replacements.
Inventor: George Wiseman, Oroville, Washington, USA Author of “Capacitive Battery Charger” www.eagle-research.com
Many officials and scientists worried. Few knew what to do. That is when Thomas L. Neff, a physicist at the Massachusetts Institute of Technology, hit on his improbable idea: Why not let Moscow sell the uranium from its retired weapons and dilute it into fuel for electric utilities in the United States, giving Russians desperately needed cash and Americans a cheap source of power?
Dr. Neff fathered the atomic recycling program in spite (or perhaps because) of his lack of name recognition, his inexperience on the world stage and his modest credentials in arms control. Moreover, he not only came up with the original plan but shepherded it for decades. “I was naïve,” Dr. Neff, 70, recalled in a recent interview. “I thought the idea would take care of itself.”
Nuclear experts hail it as a remarkable if poorly known chapter of atomic history. The two decades of bomb recycling, they say, not only reduced the threat of atomic terrorism and helped stabilize the former Soviet Union but achieved a major feat of nuclear disarmament — a popular goal that is seldom achieved. “It’s an amazing thing,” said Frank N. von Hippel, a physicist who advised the Clinton White House and now teaches at Princeton. The wave of arms destruction, he said, eliminated up to a third of the planet’s atomic bomb fuel, making it “the biggest single step” in the history of nuclear arms reduction.
He called Dr. Neff an underappreciated hero, adding that in a time of governmental muddle and paralysis, his success was a striking example “of what one person can do.” Thomas Lee Neff was born in 1943 in Oregon, the older of two boys; his family raised chickens and grew most of its own food. He studied math and physics at Lewis & Clark College in Portland, graduating with highest honors, and received his Ph.D. in physics from Stanford. As a senior M.I.T. researcher, he specialized in energy studies, writing books on nuclear power, solar energy and, in 1984, the global uranium market. His timing was propitious. In the nuclear age, the rare isotope uranium 235 has played starring roles in war and peace. When highly purified, to a level of 90 percent, it fuels atom bombs; at 5 percent, it powers nuclear reactors for electric utilities. As the Cold War ended, Dr. Neff wondered whether these disparate worlds might be able to do business together. When Washington and Moscow announced major unilateral arms reductions in late 1991, he recalled, “I said: ‘Wow. What’s going to happen to all these weapons?’ ” Dr. Neff, like many experts of the day, worried that the Soviet Union was ill equipped to deal with thousands of discarded bombs. The treaties and independent actions of the Cold War allowed nuclear arms taken from bombers and missiles to be kept in storage, raising the possibility of reuse, diversion and theft. The beleaguered communist state, he feared, was already cutting back on nuclear upkeep, workers’ pay and dozens of measures meant to keep weapons safe. He also suspected that newly impoverished Russian nuclear scientists, once a pampered elite, might seek work elsewhere. “It all sounded dangerous,” he said. His solution was atomic recycling. The question was how to float the idea. On Oct. 19, 1991, nuclear experts filed into the Diplomat Room of the State Plaza Hotel in Washington. The agenda of the nongovernmental meeting was demilitarization. A Soviet delegation attended, as did Dr. Neff. Outside the conference room during a break, he approached a leader of the Soviet bomb complex, Viktor N. Mikhailov, a canny apparatchik known for his love of Western cigarettes. Dr. Neff asked whether he would consider selling the uranium in Soviet weapons. “Interesting,” he said Dr. Mikhailov replied, puffing away. “How much?” Five hundred metric tons, Dr. Neff said, giving what he considered a high estimate for the quantity of Soviet bomb fuel soon to become surplus. “If I had known how much they really had,” he recalled, “I would have said 700 tons.” Even so, 500 metric tons was a lot: 1.1 million pounds, heavier than a fully loaded 747 jetliner. Five days later, Dr. Neff made his idea public in an Op-Ed article in The New York Times, “A Grand Uranium Bargain.” The illustration showed a kitchen pot and spoon floating eerily above a countertop and just behind an open window. Outside was a bomber. “If we do not obtain the material,” he warned, shadowy agents in the former Soviet Union, perhaps uncontrolled by central authority, might seek to “sell weapons-grade materials to the highest bidders.” The idea gained support in both Washington and Moscow. Carrying it out, through a tangle of conflicting state and commercial interests, was another matter. Dr. Neff was there to prod it along at almost every turn. In late December 1991, he was among the last Westerners to see the Soviet hammer and sickle flying over the Kremlin. The first shipment of uranium arrived in 1995; 250 more followed over the next 18 years. Last month, a freighter sailing from St. Petersburg to Baltimore delivered the last shipment. Strapped into transport pallets were giant steel drums, each holding about two bombs’ worth of diluted uranium. Dr. Neff estimates that he flew 20 times to Russia and other former Soviet states to work on the original deal and its amendments. He says a book he is writing draws on thousands of documents. Thomas B. Cochran — a senior scientist at the Natural Resources Defense Council in Washington who helped organize East-West interactions at the Cold War’s end, including the gathering where Dr. Neff met the Soviet official — said the American physicist deserved “99 percent of the credit” for the uranium deal. Its most important result, he added, was simply improving the relationship between the United States and Russia at a critical moment in history. Last month, the Russian Embassy in Washington held a reception to mark the end of the Megatons to Megawatts program. Dr. Neff was an honored guest. A brochure handed out at the reception reprinted his Op-Ed article, praising the commercial deal as a first for nuclear disarmament. It put the overall cost of the transaction at $17 billion. Uranium from the dismantled weapons, it said, was diluted into 15,432 tons of low enriched uranium. The resulting reactor fuel supplied half of all American nuclear power plants. The total electric power, it said, could illuminate the whole of the United States (roughly 20,000 cities and 115 million households) for about two years — or Washington, D.C., for 185 years. The atomic sale, the brochure said, “is widely held to symbolize the end of the era of confrontation between the two major nuclear powers.” In an interview, Ernest Moniz, the federal secretary of energy and a former colleague of Dr. Neff’s at M.I.T., praised him for not only proposing the plan but helping guide it for more than two decades. “If he hadn’t stuck with it,” Dr. Moniz said, “it could have very easily been one of these great ideas that ends up just spinning its wheels.” Millions of idealists, from President Obama on down, have sought a world without nuclear weapons. Dr. Neff, despite doing more than almost anyone to advance that goal, is circumspect about what he accomplished. He made no mention of energy windfalls, geopolitical realignments or the biblical injunction to turn swords into plowshares. The lesson of the story, he remarked in an interview, “is that private citizens can actually do something.” Source: http://www.nytimes.com/2014/01/28/science/thomas-l-neffs-idea-turned-russian-warheads-into-american-electricity.html?ref=williamjbroad&_r=0 United Kingdom Nuclear Industry’s Financial and Safety Nightmare Institute of Science in Society Report 22/09/08 A devastating new report exposes UK’s unfolding nuclear catastrophe – Dr. Mae-Wan Ho Voodoo economics dooms nuclear renaissance Paul Brown, environmental correspondent of The Guardian newspaper in Britain, has produced a detailed report documenting why it is not possible to achieve what the UK Government says it will do, build a new generation of nuclear stations without public subsidy14. New build will not be possible without large sums of taxpayers’ money being pledged, and extending the unlimited guarantees to underwrite all the debts of the existing and future nuclear industry.” One should point out here that it appears impossible to have new nuclear build in the United States even with extremely generous public subsidy15 (Nuclear Renaissance Runs Aground, SiS 40). In the UK, there is already an extensive hidden subsidy to the industry. Brown’s report exposes how badly the nuclear industry has performed over the entire 50 years of unfulfilled promises, and the escalating bill to the taxpayer. The UK nuclear industry, like that in the US16, has never completed any project on time or on budget and has saddled the nation with a mammoth nuclear fuel reprocessing complex at Sellafield that’s a financial as well as safety nightmare. British Energy, the commercial company privatized in 1996, soon ran into serious financial trouble17 (see Box 1), and had to be taken over by the government. That meant the taxpayer has essentially underwritten all its debts and liabilities so the company can never go bankrupt. Brown remarks: “This commitment dwarfs the risk to the taxpayer of the Northern Rock nationalization.” It means paying for the maintenance and decommissioning of ageing nuclear power stations, and worst of all, the upkeep of the Sellafield nuclear reprocessing complex. British Energy British Energy is UK’s largest electricity provider established and registered in Scotland in 1995 to operate the 8 most modern nuclear stations, two advanced gas-cooled reactors (AGRs) from Scottish Nuclear and five AGRs and one pressurized water reactor (PWR) from Nuclear Electric. The remaining Magnox power stations from these two companies were transferred to Magnox Electric which later became the generation division of British Nuclear Fuels (BNFL). British Energy was privatized in 1996 and bought the 2 GW Eggborough coal fired station from National Power in 2000. The company ran into financial trouble in 2002, when it first approached the British government for financial aid. In September 2004, the government bailed out the company with over £3 billion investment, and took over all its liabilities. So why is the UK government so keen to build new nuclear stations? Its own figures show that a new nuclear power program will cut gas imports by only seven percent and carbon emissions by four percent. Yet the program for four gigantic new stations will get policy encouragement and public subsidy on the false claim that Britain needs them for energy security and reducing carbon emissions. It will take 10 to 20 years before the first new nuclear stations can be built and producing power in Britain. By that time, the liabilities will be so great that the Government will have to renationalize British Energy, Brown says. The crisis may come much sooner, and British Energy may have to start closing some of its nuclear stations permanently because the only remaining storage space for spent fuel at the Sellafield complex in Cumbria is running out. Three of the four new reactor designs being put forward for UK construction have never been built. The only proposed “Generation III” plant under construction is Areva’s EPR, an advanced pressurized water reactor (also under consideration in Ontario) in Finland. It was due to generate electricity in 2009. Delays have dogged the construction from the outset and its completion date has been repeatedly put back, currently to 2011, with additional cost of €1 billion to the €3 billion originally agreed. Nightmare at Sellafield Sellafield’s nuclear complex consists of five important operations: two reprocessing plants, the MOX (mixed oxide fuel) plant, the evaporators, and the vitrification plant (that turns highly dangerous radioactive liquid waste into safer glass). With more than 10,000 employees, the massive complex is in crisis. Its reprocessing works and plutonium fuel plant are all failing, costing the taxpayer £3 billion a year and rising. The taxpayer already faces £73 billion clean-up bill for decommissioning existing nuclear plants, most of that will be spent in Sellafield. Reporting for the BBC, David Shukman wrote of his visit to Sellafield18: “I saw for myself one of the “ponds” in which an unknown mass of radioactive material was dumped in the 1950s... Beneath the unruffled surface of the water lies an unrecorded collection of rusting metal containers holding radioactive waste, including spend fuel rods… Beside it, workers are constructing a vast new building to handle the materials when a retrieval operation eventually gets under way.” Jim Morse, a senior director at Sellafield sums up the sorry state of affairs in record keeping: “We still have a lot to discover, we haven’t started waste retrieval in those parts of the estate where the degradation and radioactive decay has been at its greatest.” Morse also said the cost of cleanup could go up even further by “some billions”. That’s not the only problem. The flagship Thorp reprocessing plant, built to extract plutonium and unused uranium from spent nuclear fuel19 (see Energy Strategies in Global Warming: Is Nuclear Energy the Answer? SiS 27) was closed for three years from 2005, and remains under severe operating restrictions and cannot complete its long-overdue contracts to process spent foreign fuel into MOX fuel20. The closure of the elderly Magnox reprocessing plant has been postponed, leaving the UK unable to meet its international commitments to cut radioactive discharges into the Irish Sea. The plants for dealing with the residue of reprocessing – the volatile and dangerous heat-producing high-level liquid waste – fail to work as designed, causing the whole Sellafield production line to seize up. The MOX plant is supposed to make money by turning plutonium and uranium into new fuel, but has been a technical and financial disaster. The fuel was supposed to be the safe way of returning tons of plutonium recovered during reprocessing to its country of origin. This plan has failed, but the Government has no policy for dealing with the ensuing economic and political crisis. As a result, Sellafield is becoming the world’s nuclear dustbin, because foreign nuclear wastes are not being repatriated. As Peter Bunyard wrote in 2005 (SiS 27)21, many critics of MOX within and outside the nuclear industry have repeatedly pointed out that the gains are far outweighed by economic and environmental problems. “In France, reprocessing spent fuel to extract plutonium for MOX fuel manufacture will save no more than 5 to 8 per cent on the need for fresh uranium. Meanwhile, as experience in both France and Britain has shown, reprocessing spent reactor fuel leads to a hundredfold or more increase in the volume of radioactive wastes. In the end, all the materials used, including tools, equipment and even the buildings become radioactive and have to be treated as a radioactive hazard.” It is highly questionable whether the use of MOX fuel will actually reduce the amount of plutonium. Reactors have to be modified to take MOX fuel, and it is estimated that supply exceeds demand by a factor of two. Meanwhile MOX fuel contains up to 5 percent plutonium and is ideal for terrorists, as the plutonium can be easily extracted to make bombs. The world’s nuclear waste dump with no end in sight While Britain piles up its own and foreign nuclear waste, there are currently no plans or sites for a repository to store or dispose of it22. The earliest dates for a deep underground intermediate waste repository are notionally 2045 and high-level waste 2075. In reality there are no plans for either. Storage space for spent fuel is also running out at Sellafield. Spent fuel assemblies are stacked three deep at the reception ponds and is already a major source of hazard23 (see Close-up on Nuclear Safety, SiS 40). If Sellafield cannot take any more spent fuel, then British Energy’s reactors will have to shut down. In the meantime, an average of 300 tons of spent fuel has continued to be delivered to Sellafield each year and none has been cleared through reprocessing in order to free storage space for those continued deliveries. There is an increasing backlog of both spent fuel and all forms of waste. UK’s Nuclear Decommissioning Authority reveals in June 2007 that there are 30,000 tons of uranium and 100 tons of plutonium in store, but no policy for managing the material in the long term. In the context of a massive new nuclear building program, Sellafield is not just a huge embarrassment but a graphic demonstration of how expensive mistakes can be. The National Audit Office says in 2008 that it is creating an “apparently ever escalating bill” for the taxpayer. Massive nuclear liabilities discounted by the government In April 2007, a cost benefit analysis by the Department for Business, Enterprise and Regulatory Reform (BERR) concludes that nuclear power is likely to cost 4.8 pence per kilowatt-hour to produce, provided all future nuclear waste costs are discounted. British Energy’s undiscounted liabilities in 2007 were £14.5 billion, more than double the amount in the liabilities fund designed to pay decommissioning costs24. The nuclear liabilities fund is invested in a supposedly ring-fenced fund, like a pension fund for nuclear facilities. But in the past those funds have been raided by the nuclear industry to build new nuclear facilities, such as Sizewell B, and the money has evaporated. The government has pledged this will not happen again, and the discount rate of 3 percent is based on the assumption that the liabilities fund will grow at the rate of 3 percent. The theory is that by the time decommissioning is necessary the fund will neatly pay for everything. The National Audit office and the House of Commons Committee on Public Accounts concluded: “the taxpayer is still exposed.” Liabilities could easily exceed assets when prices are volatile. In particular, the price of uranium is rising, and experts all say that the supply of good quality uranium is finite, which is also one major reason nuclear power is unsustainable25 (see The Nuclear Black Hole, SiS 40). . A shortage of suitable uranium would do to nuclear fuel what the price of oil has done to the cost of running the family car. In January 2008, the cost of uranium had gone up to US$95 a pound, compared with $85 a pound in March 2007. This would drive up nuclear fuel costs by £146 million a year. It is quite clear that the British government has been doing everything to make nuclear power look economically competitive, and will give all the overt and covert subsidies to make it happen. The new breed of nuclear power stations are going to be among the biggest power plants in Britain and will be located far away from where most of their electricity will be used. This will require a large investment in the national grid adding further to the financial drain and the inefficiency of the nuclear option. Source: http://www.i-sis.org.uk/NuclearFinancialandSafetyNightmare.php |