Summary

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  • Caselist.RoundClass[11]
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EntryDate

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1		-2016-11-14 05:11:34.479
	1	+2016-11-14 05:11:34.0

Caselist.CitesClass[12]

Cites

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	1	+-extemp text-
	2	+Generation IV nuclear power prevents meltdowns and remediates nuclear waste—investment is the key barrier to development
	3	+Robock 16 Zachary Robock, JD, associate at Jones Day, where his practice focuses on corporate and energy matters, “Economic Solutions to Nuclear Energy's Financial Challenges”, 2016, http://repository.law.umich.edu/cgi/viewcontent.cgi?article=1053andcontext=mjeal
	4	+Gen IV reactors are not some far-off theoretical technology; several have been successfully operated, accumulating approximately 400 total reactor-years of experience,35 and there is increasing domestic and international momentum in advanced nuclear energy. In 2011, thirteen countries, including the United States, extended an agreement to focus their research and development efforts on six Gen IV reactor designs: Gas Cooled Fast Reactor; Lead-Cooled Fast Reactor; Molten Salt Reactor; Supercritical Water- Cooled Reactor; Sodium-Cooled Fast Reactor; and Very High Temperature Reactor.36 The first fleet of commercial Gen IV reactors are expected in 2030–2040.37∂ Companies in the United States are actively pursuing advanced nuclear technologies. For example, FLiBe Energy is based in Alabama and headed by Kirk Sorenson, a former NASA scientist and the former Chief Nuclear Technologist at Teledyne Brown Engineering. FLiBe is developing a thorium-fueled molten salt reactor.38 TerraPower is chaired by Bill Gates (of Microsoft), and is developing a standing wave reactor—a version of a sodium-cooled fast reactor—designed by Pavel Hejzlar, who previously worked as the principal research scientist and program director for the Advanced Reactor Technology Program and Center for Advanced Nuclear Energy Systems at MIT.39 Transatomic Power, based in Boston, was founded by recent MIT PhD graduates to develop a molten salt reactor specifically intended to consume existing nuclear reactor waste, without re-enrichment.40 A team involving University of Michigan nuclear engineers recently developed a mechanism to simulate reactor materials’ integrity under the stresses of molten salt fast reactions, which should help drive critical RandD.41 Finally, among other initiatives, the Obama administration recently committed $40 million to two companies involved in advanced nuclear re- search, X-energy and Southern Company.42∂ Internationally, India, which has substantial reserves of thorium, an alternative to uranium fuel, has been aggressively developing its nuclear power industry with a long-term plan toward advanced nuclear reactors, including a Gen IV prototype expected to come online in 2016.43 France has historically generated most of its power from nuclear energy and is pursuing three Gen IV technologies.44 China is similarly increasing its nuclear power resources while developing advanced nuclear to meet future needs.45∂ On the other hand, the technology still has hurdles to overcome. More research and testing are needed to confirm the long-term integrity of materials used to contain the reaction.46 For example, some proposed salts can react poorly with water (sodium is flammable in contact with water), but others, such as FLiBe (a mixture of lithium fluoride and beryllium), are more stable.47 Notably, many of the technological hurdles to commercialization can be studied and addressed simultaneously, rather than needing to go sequentially.48 Therefore, more upfront funding can accelerate the timeline for development.∂ A. Safety Improvements∂ Next generation nuclear technologies offer several inherent safety advantages over older reactor designs, including low-pressure operation and passive cooling that eliminates the need for battery or diesel backups. Existing nuclear technology is akin to a car with the accelerator stuck at full throttle that must be actively contained. Advanced nuclear is the inverse. The reaction must be actively encouraged; if power is lost, the reaction will fizzle out due to its natural thermodynamic properties.49 This is both a challenge and a benefit to the technology.∂ Gen II and III light water reactors (LWRs) use water as both a coolant and heat transfer medium. LWRs must be highly pressurized in order to keep the water liquid. LWRs operate most efficiently at 500 to 600 degrees Fahrenheit, yet water boils at 212 degrees.50 To keep the water liquid at these high temperatures, the reactor must be pressurized to 1,000 to 2,000 pounds per square inch (for reference, a moose weighs about 1,000 pounds51), or 75- to 150-times normal atmospheric pressure.52 This pressure makes for a fairly tenuous situation.53 Any water that escapes will flash instantly to steam (often radioactive steam), building pressure in the containment vessel. If there is a loss of coolant—as occurred in different ways at Three Mile Island, Chernobyl, and Fukushima—backup systems run by batteries and diesel generators are supposed to keep coolant circulating around the reactor.54 These failed tragically in Fukushima due to the intensity of the earthquake and tsunami, which dislodged and flooded diesel generators.55 The batteries worked for a time, but didn’t last.56∂ One new safety feature of Gen III reactors is to store emergency water above or nearby the reactor to deploy automatically and without the need for power in the event of a power loss or other loss of coolant.57 This is an improvement over Gen II, but is hardly a fundamental fix. The water storage could become dislodged by the same event (e.g., earthquake, tsunami, or explosion) that caused the primary coolant or power loss in the first place. Moreover, many passive safety systems rely on intricate fail-safe mechanisms—sensitive valves to detect changes in core pressure, or complex condensation and pressurization systems,58 which could be dislodged during an earthquake, explosion, tsunami, or other physically disruptive event. In short, regardless of the particular backup system, the high operating pressures and natural tendency for coolant to flash to steam make for an unavoidably tenuous situation, even with passive backup systems.59∂ In comparison, many Gen IV reactors will use molten salts, lead, or sodium (referred to collectively as “salts” for simplicity) for cooling and heat transfer, rather than water.60 Salts naturally become molten at the high temperatures necessary to run nuclear reactors efficiently, so they need not be highly pressurized. These salts also do not vaporize until extremely high temperatures—sodium boils at roughly 1,600 degrees Fahrenheit61 and certain fluoride salts boil at roughly 3,000 degrees.62∂ The ability to operate at low pressure enables molten salt reactors to employ a passive emergency cooling mechanism in the event of power loss. During normal operation, the reaction occurs in the reactor core, which has a drain at the bottom, like a sink, as shown in Figure 1.63 The drain is normally plugged with a stopper comprised of the same salt used as a coolant in the reaction.64 The salt stopper is actively cooled, keeping the stopper solid.65 If there is a power loss, the stopper would cease to be cooled and would melt.66 The reactor contents (molten salt + nuclear fuel) would drain into a reinforced drainage tank designed to passively cool the contents.67 Unlike water, the salt coolant would not boil away, but would remain in the drain tank and continue to cool the fuel.68 Moreover, many Gen IV technologies have a strong negative temperature coefficient, meaning that the reaction slows as the temperature rises, thereby naturally cooling the reactor contents in the event of an emergency drainage scenario and substantially reducing the possibility of a meltdown scenario.69 ∂ B. Reduction in Nuclear Waste∂ Advanced nuclear technologies can also dramatically reduce both the volume and lifespan of radioactive waste, which is one of the critical environmental challenges in nuclear power. Different Gen IV designs reduce nuclear waste in different ways. In order to achieve more complete burnup, some Gen IV designs operate as “fast” reactors,70 while others utilize innovative fuel mixes and processes.71 As shown in Figure 2, below, a nuclear reaction occurs when a neutron “bullet” strikes a uranium (or thorium or plutonium) atom, fissioning the atom and releasing: (a) energy/heat; (b) more neutrons; and (c) nuclides, which are the resultant atoms from the splitting of the uranium atom.72 Nuclides are a substantial component of the nuclear waste ultimately generated by nuclear reactions.73∂ Gen II and III reactors are all LWR, which operate as thermal, or slow, reactors.74 The water in these reactors acts as a “moderator,” slowing the neutron bullets down in order to maximize the likelihood of a neutron bullet striking another uranium atom.75 Moderating (slowing) these neutrons reduces their velocity and hence their energy.76 Lower energy neutrons result in less burnup of the fuel, resulting in substantial amounts of long-lived nuclear waste.77 In contrast, fast reactors do not moderate neutrons, resulting in fast (high-energy) neutrons, which are capable of more complete burnup (including the nuclides).78 “Fast reactors hold a unique role in the actinide i.e., nuclide management mission because they operate with high energy neutrons that are more effective at fissioning actinides nuclides.”79 By more completely consuming the fuel and nuclides, fast reactors substantially reduce the volume of nuclear waste generated.∂ Importantly, the waste that is generated will decay to safe levels in approximately 300 years, compared with the 300,000 years it will take for nuclear waste from today’s thermal reactors to decay to safe levels.80 Fast reactors can even be used to consume existing nuclear “waste” as a beneficial power source.81 The ability to utilize existing nuclear waste can eliminate or reduce the need to mine for uranium, thereby reducing environmental damage from mining and from long-term waste disposal.82∂ Fast reactors are not the only way that Gen IV reactors aim to substantially reduce long-lived nuclear waste. Molten salt reactors operate as thermal, not fast, reactors, but are able to achieve almost complete burnup of the uranium fuel by using uranium dissolved in liquid salt, rather than solid uranium pellets surrounded by water.83 This allows for (1) filtration of the uranium-salt mixture, thereby removing certain fission products that would otherwise slow the reaction down; and (2) the continuous addition of fuel.84 With proper filtration, the liquid fuel can remain in the reactor for decades, enabling much more complete burnup. This process can also utilize existing nuclear waste as fuel, thereby not only minimizing future nuclear waste, but actually reducing the current stockpile.85∂ III. WHAT IS HOLDING ADVANCED NUCLEAR BACK? OVERVIEW OF COSTS∂ What is holding nuclear power back from the “jet age”? Simply put, “costs remain the biggest hurdle for the nuclear industry.”86 Once operational, a nuclear plant can produce electricity at a marginal cost below that of electricity from fossil fuels.87 However, high start-up costs (and the associated cost of capital), long repayment periods, and regulatory uncertainty put nuclear power at an investment disadvantage.88 Advanced nuclear should prove even more operationally efficient than existing plants, but entails even higher upfront costs, given the research and development necessary to safely commercialize the technology.89

EntryDate

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	1	+2016-11-14 05:11:36.892

Judge

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	1	+x

Opponent

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	1	+x

ParentRound

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	1	+11

Round

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	1	+1

Team

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	1	+Sunset bhat Neg

Title

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	1	+SO - Gen IV CP

Tournament

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	1	+Greenhill