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Is Thorium a viable source of Nuclear Energy that can replace Uranium for our future’s needs?

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Presentation on theme: "Is Thorium a viable source of Nuclear Energy that can replace Uranium for our future’s needs?"— Presentation transcript:

1 Is Thorium a viable source of Nuclear Energy that can replace Uranium for our future’s needs?

2 An Objective Look at Nuclear Energy ❏ Nuclear Energy has prevented about 1.8 million deaths between 1976 and 2009 ❏ Even if you count Chernobyl and Fukushima disasters, Nuclear energy ranks last in death per energy unit generated per year (behind coal, oil, biomass, peat, natural gas, solar, hydro, and wind) ❏ Nuclear waste is stored deep inside the ground while toxic bi-product of fossil fuels are pumped into the air we breath everyday ❏ The lesser of evils!

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4 HOW DOES THORIUM COMPARE TO URANIUM?

5 Round 1: Cost ➔ The capital costs of thorium reactors would be lower than conventional nuclear reactors; a 1 gigawatt (GW) thorium power plant would cost at most an estimated $780 million in comparison to capital costs currently of $1.1 billion per GW for a uranium-fueled reactor. ➔ Less manpower would be required to operate the plant; for a 1 GW power plant, staffing costs may decrease from $50 million to $5 million.

6 As a result of lower capital costs, fuel costs and waste disposal costs, thorium- generated electricity costs could be lower than electricity produced from natural gas or coal. Comparing a rough estimate of the potential cost of electricity from thorium with average prices for other forms of generation, in 2002: ★ The real cost of electricity generated by U.S. nuclear power plants (uranium) was 6.7 cents per kilowatt hour (kwh). ★ Electricity from plants burning pulverized coal cost 4.2 cents/kwh to produce. ★ Electric power from moderately priced natural gas cost 4.1 cents/kwh. ★ Power from a thorium reactor would cost, by comparison, cost an estimated 1.4 cents/kwh.

7 Thus, Thorium has the potential to reduce retail electricity prices significantly

8 Round 2: Non-proliferation Thorium is not fissile; meaning it cannot go critical and generate a nuclear chain reaction. This is referred to as thorium's safety valve. Thorium needs a spark or neutron driver to get it to start a reaction and get it to produce heat energy. It must undergo neutron bombardment to produce a by-product or radionuclide that can sustain a nuclear reaction. Thorium bombardment can be controlled. A thorium-fueled reactor must be jump-started with a fissile isotope such as uranium (U 235 ) and/or plutonium (Pu 239 or Pu 241 ). Neutron bombardment of thorium results in this reaction: Th 232 + Neutron = U 233.

9 Other Claims: The absence of plutonium is in the thorium fuel cycle is claimed to reduce the risk of nuclear weapons proliferation, I do question whether is this is completely valid, given that there were a number of U-233 nuclear tests (the “Teapot tests”) in the US in the 1950s. HOWEVER, those tests have since been abandoned because U-233 was not conventional to be used as a weapon because: Uranium is way easier to control and detonate Thorium has much less explosive yield at 22

10 This reactor concept is based on a design comprised of inner seed rods of uranium which provide neutrons to an outer blanket of thorium-uranium dioxide rods, creating U-233, which in turn powers the nuclear reactor. The important difference with this design is in the nature of the spent fuel. As advocates of thorium such as the U.S. company Lightbridge purport, this process would realize a significant reduction in the “quantity and quality” of plutonium produced within the spent fuel, achieving upwards of an 80% reduction in plutonium. In addition, reactors which use a thorium based seed and blanket design are engineered so that the U-233 which is produced is simultaneously denatured or blended with U-238, further reducing its suitability for a nuclear weapon.conceptrealize Thorium Seed and Blanket Design

11 Terrorism 101 1. Thorium itself isn’t fissile so you’ll have to steal it when the thorium fuel cycle produces the fissile material U-233 2. Go into the reactor and steal the fissile U-233 as hot liquid while exposing yourself to dangerous isotope U-232 3. Unless you have a robot, you’re dead.

12 Although Thorium is weaponizable, it is incredibly difficult to achieve and is not even a good weapon.

13 Round 3: Safety ❏ Thorium dioxide melts at 550 degrees higher temperatures than traditional Uranium dioxide, so very high temperatures are required to produce high- quality solid fuel. Additionally, Thorium is quite inert, making it difficult to chemically process ❏ The Th-U cycle invariably produces some U-232, which decays to Tl-208, which has a 2.6 MeV gamma ray decay mode. Bi-212 also causes problems. These gamma rays are very hard to shield, requiring more expensive spent fuel handling and/or reprocessing.

14 However... ❖ The explosive pressures involved are contained by a system of highly engineered, highly expensive piping and pressure vessels (called the “pressure boundary”) ❖ The ultimate line of defense is the massive, expensive containment building surrounding the reactor, designed to withstand any explosive calamity and prevent the release of radioactive materials propelled by pressurized steam. ❖ The signature safety mechanism is that the coolant—liquid fluoride salt—is not under pressure ❖ Therefore, Disruption in a transport line would result in a leak, not an explosion, which would be captured in a noncritical configuration in a catch basin, where it would passively cool and harden ❖ Contains safety feature of LWR which is its negative temperature coefficient of reactivity ❖ As a last line of defense, have a freeze plug at the bottom of the core—a plug of salt, cooled by a fan to keep it at a temperature below the freezing point of the salt ➢ If the temperature rises above the critical point, the plug melts and the liquid in the core is immediately evacuated into a catch basin

15 Radiation exposure can be a problem for workers in the plant due to the gamma rays which are very hard to shield

16 The reactors are essentially ‘meltdown-proof’

17 Life Cycle Analysis No conversion and enrichment needed for Thorium Approx. the same costs of Thorium to traditional reactors

18 So why the hell are we not using Thorium? Precedence Had it not been for mankind’s seemingly insatiable desire to fight, thorium would have been the world’s nuclear fuel of choice. Unfortunately, the Cold War pushed nuclear research toward uranium.

19 Remember Beta VCRs, anyone? On the technical front they beat VHS hands down, but VHS’s marketing machine won the race and Beta slid into oblivion. Thorium reactors aren’t quite the Beta VCRs of the nuclear world, but the challenge they face is pretty similar: it’s damn hard to unseat the reigning champ.

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