Lecture #17 ER 100/200 Pub Pol 184/284 Oct. 29, The Nuclear Fuel Cycle: Waste, Risk, and Economics

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1 Lecture #17 ER 100/200 Pub Pol 184/284 Oct. 29, 2015 The Nuclear Fuel Cycle: Waste, Risk, and Economics

2 The Nuclear Fuel Cycle Economics Radioactive Waste Disposal Safety Security

3 The first nuclear reactors: submarines (constrained engineering) Good ideas are not adopted automatically. They must be driven into practice with courageous patience. -Admiral Hyman G. Rickover, father of the U.S. Nuclear Navy

4 The first commercial nuclear power plant Shippingport, PA achieved criticality in 1957 decommissioned in 1982

5 California s electricity mix (2012) Nuclear power plants in CA: Diablo Canyon Power Plant (DCPP) San Onofre Nuclear Generating Station (SONGS) Source: California Energy Commission s Energy Almanac, m_power.html

net respectively, when operating at 100% capacity. Bechtel was.

6 California s electricity mix (2012) Units 2 and 3 Combustion Engineering two-loop pressurized water reactors, generated 1,127 MWe gross, and 1,070 MWe net respectively, when operating at 100% capacity. Bechtel was... embarrassed in 1977, when it installed a 420-ton nuclear-reactor vessel backwards" at San Onofre.

7 California s electricity mix (2015) Nuclear power plants in CA: Diablo Canyon Power Plant (DCPP) [San Onofre Nuclear Generating Station (SONGS), closed; nuclear production now ~5% in CA] Source: California Energy Commission s Energy Almanac, m_power.html

8 Some nuclear physics

9 Periodic Table of the Elements

10 Chart of the Nuclides

11 Fission: the splitting of an atom into two or more nuclei Reaction Energy (MeV) Fission 200 Fusion (D,T) 17.6 Chemical ~10-6

12 Comparison with Fossil Fuels Chemical reaction 12 C + O 12 CO + 4 ev 2 2 y 200MeV Nuclear Fission 0n 1 x 92U 235 0n 1 92U Pu 239 per atom [ev] per gram [W hr] Carbon ~ 4 ~ 10 Uranium ~ 2E8 ~ 2E7 92U 235

13 Comparison to Fossil Fuels 120 gallons of oil 1 ton of coal 0.5 cubic meter of natural gas 200 MeV per reaction ~100 ev per reaction

14 Why it works: Binding Energy DE = Dmc 2 The mass of an atom is smaller than the sum of its parts. The difference is called the binding energy the energy required to hold the atom together.

15 The discovery of nuclear reactions need not bring about the destruction of mankind any more than the discovery of matches. Albert Einstein

16 The front end of the fuel cycle

17 17 Uranium Global Resources

18 Uranium Resources 18

19 LWR Fuel Cycle

20 Uranium U mined as U 3 O 8 Natural abundance: 99.3% of 92 U % of 92 U U 235 is fissionable by slow neutrons 92U 238 is fissionable only by fast neutrons (but is a fertile isotope) Our fuel cycle uses fission of U-235 to produce electricity Source: World Nuclear Association

Australia. Image credit: http://www.abc.net.

21 Mining extraction of natural ore from the ground Ranger open pit uranium mine, Australia. Image credit:

22 Mining (cont.) In-situ leaching of U, a.k.a. in-situ recovery (ISR) Little surface disturbance, no tailings

Reduction Company Mill, Moab, UT. Image credit: http://www.

23 Milling Extraction of uranium from ore by crushing, grinding, solventextraction separation Creation of mill tailings Uranium Reduction Company Mill, Moab, UT. Image credit:

24 Conversion From U 3 O 8 yellowcake (~80% U) to UF 6 gas Fluorine is used because: -only one isotope of F -commercially viable -UF 6 the only uranium compound that is a gas at room temperature

25 Enrichment 0.7 % 235 U % 235 U for PWR Two main enrichment technologies: Gas centrifuge Gaseous diffusion Graham s Law:

26 Depleted Uranium Parking lot full of 750,000 MT of DU cylinders in Paducah, KY

tapered slightly on each end, which allows pellets to expand and contract through drastic temperature changes inside reactor without

27 Fuel Fabrication Final machined pellets are typically about 0.5 inch in length & about 0.33 inch in diameter. UF 6 converted into UO 2 powder, then sintered and pressed into pellets at >1700 C MOX fuel: a combination of UO 2 and PuO 2 Pellets tapered slightly on each end, which allows pellets to expand and contract through drastic temperature changes inside reactor without damaging fuel or cladding materials Image Source: See note 9 Image So They are "dishe end. End tape expand and con drastic tempera reactor without cladding materi

28 Fuel Fabrication (cont.) Fuel pellets assembled into fuel rods with Zircaloy cladding and bundled into a (square) fuel assembly

29 Shipping of Fuel to Reactor which is usually performed by truck Images Source: See Note 6 Images Source: See Note 6 Images Source: See Note 6

30 The Reactor

31 Nuclear energy systems require three basic components!fuel!fissile material necessary to maintain the chain reaction!moderator!reduces neutron energy to enhance fission probability!light material, non-absorbing!water, graphite!coolant!removes the heat generated in the fuel!carries the heat for conversion

32 Light Water Reactors are the Light Water Reactors: the majority of all nuclear power plants majority of all nuclear power plants Reactors in operation worldwide Reactors under construction worldwide Type No. of Units Total MWe BWR 92 83,656 FBR GCR 18 8,909 LWGR 16 11,404 PHWR 44 22,441 PWR ,121 Type No. of Units Total MWe BWR 3 3,925 FBR 2 1,220 LWGR PHWR 4 1,298 PWR 40 35,515 Total 50 42,883 Total ,221 BWR GCR FBR LWGR PWR PWHR Boiling Water Reactor Gas Cooled Reactor Past Breeder Reactor Light Water Graphite Reactor Pressurize Water Reactor Pressurized Heavy Water Reactor

33 Life Cycle GHG Emissions ~100 nuclear power by 2020, Tripling 2014 to reach 58 million kilowatts, ~ 2 billion per reactor, 5 year construction time

34 Pressurized Water Reactors: two-loop heat conversion system Pressurized Water Reactors use a two-loop heat conversion system

35 Boiling Water Reactors: single-loop heat conversion system Boiling Water Reactors use a single-loop heat conversion system

36 GenIV systems to improve economics, safety, sustainability Generation IV systems are will improve economics, safety, and sustainability

substantial at temperatures above 1000 C Volatile fission products

38 LWR fuel releases hydrogen and fission products when overheated Zirconium cladding reaction with steam to produce hydrogen becomes substantial at temperatures above 1000 C Volatile fission products released as noble gases (e.g. Kr) or aerosols (e.g. I, Cs) Fuel pellets melt at 2600 C

TMI Events: March 28, 1979 4 a.m. Unit 2 has been in service for about three months. Unit 1 is shut down for refueling.

39 TMI Events: March 28, a.m. Unit 2 has been in service for about three months. Unit 1 is shut down for refueling. A minor malfunction in the non-nuclear part of Unit 2 occurs, triggering a series of automated responses in the reactor's coolant system, including the opening of a relief valve on top of the pressurizer to relieve pressure. The relief valve fails to close automatically when the pressure drops. Control room operators misread the situation and mistakenly believe coolant is being pumped into the system. Meanwhile, the valve remains open for 2 1/4 hours as precious reactor coolant spews out. An automated emergency cooling system also is turned off. 6:48 a.m. By now, high radiation levels exist in several areas of the plant, and evidence indicates as much as two-thirds of the 12-foot-high core has stood uncovered. A partial meltdown of the fuel bundles occurs.

41 Chernobyl: Immediately after the Accident At 1:30 A.M. on April 26, 1986 reactor #4 exploded due to built up steam in the reactor core itself. Twenty percent of the radioactive contents of the core were blown 2/3 of a mile in the air.

42 RBMK-1000 Reactor

43 The Sarcophagus A twenty-eight story building, called the sarcophagus, constructed of lead, steel, and concrete was built over the crumbled remains of the power plant

44 Chernobyl pictured in 1995 (Notice there are NO containment domes.)

46 The Cost of Nuclear Power from the U. S. Civilian Reactor Fleet Hultman, Koomey & Kammen (2007) ES&T

47 Can nuclear compete? (depends who you ask)

48 The back end of the nuclear fuel cycle

49 An Example of Nuclear Fuel Cycle 49

50 Nuclear Fuel Cycle and Waste Generation ~0.2 ton U 27.3 ton 27.5 ton 26 ton 26 ton U 0.95 ton FP 0.27 ton Ac LLW 1, liter drums 0.24 ton Pu ~ 0.5 ton U TRU/LLW 165 ton (0.3%U-235) 167 ton < 0.26 ton U 0.95 ton FP 0.27 ton Ac 100,000 Ton ore 0.2% U3O8 = 181 ton U Airborne Rn Mill tailings U7% Th %, Ra 98% ~ 1 ton U Ra, Th 50 1 GWe, LWR, 1 year Reprocessing scheme Thermal efficiency Capacity factor 0.8

51 Half-life: basics The rate of radioactive decay is expressed in terms of half-life: dq/dt = -kq, so Q(t) = Q 0 e -kt The half-life of an element is the time required from one-half of its unstable nuclei to decay The half-life of an element, or the 1/e time is t half = 0.693/k The decay constant for U238 is 4.87 X /s The half life is therefore t half = 0.693/4.87 X /s = 1.42 X s = 4.5 X 10 9 years The half-life of U 238 is 4.5 billion years.

52 U238 decay pathway 52

53 A Variety of radiation units

55 Many of the weapons were tested in Nevada. 25-July-09 Easily viewed on Google Map, about ~ 60 miles NW of Las Vegas 55

56 Radioactive Waste

57 LWR Spent Fuel Stored in pools upon discharge

58 Transportation of Radioactive Waste

59 Storage of Radioactive Waste Provide: isolation, environmental protection, and monitoring To facilitate: treatment, conditioning, and disposal Storage may be necessary for decay and/or thermal management prior to geologic disposal. Sometimes, storage of radioactive waste is practiced for economic or political reasons.

60 Interim Storage Dry cask storage Decay storage of solidified HLW

61 Composition of Used Nuclear Fuel utonium does not occur in nature, but is instead produced from irradiation of 238 U in a reactor.

62 Reprocessing of Used Nuclear Fuel: PUREX Reprocessing facility in La Hague, France: Spen Reprocessing Complex Image Source: See Note 2

63 Reprocessing Facilities Around the World COMMERCIAL SPENT URANIUM OXIDE FUEL REPROCESSING PLANTS IN OPERATION AND UNDER CONSTRUCTION IN THE WORLD Country / Company Facility / Location Fuel Type Capacity (thm/year) France, COGEMA UP2 and UP3, La Hague LWR UK, BNFL Thorp, Sellafield LWR, AGR UK, BNFL B205 Magnox Magnox GCR Russian Federation, Minatom RT-1 / Tcheliabinsk-65 Mayak 400 VVER 400 Japan, JNC Tokai-Mura LWR, ATR Japan, JNFL India, BARC Rokkasho-Mura (under construction) LWR 800 PREFRE-1, Tarapur PREFRE-2, Kalpakkam PHWR PHWR China, CNNC Diowopu (Ganzu) LWR

64 MOX Fuel Fabrication Facilities MIXED URANIUM PLUTONIUM OXIDE (MOX) FUEL FABRICATION FACILITIES Country / Company Facility / Location Fuel Type Capacity (thm/year) France, COGEMA France, COGEMA Belgium, Belgonucleaire UK, BNFL UK Russian Federation, Minatom Cadarache Marcoule-Melox Dessel Sellafield SMP Sellafied MDF Chelyabinsk LWR, FBR 40 LWR 100 LWR 40 LWR 120 LWR 8 FBR 60 Japan, JNC Japan, JNFL Tokai-Mura Rokkasho India, AFFF, BARC Tarapur LWR, PHWR & FBR ATR 10 LWR 130

65 Vitrification of HLW Calcination followed by induction melting

66 History of U.S. Radioactive Waste Management Nuclear Waste Policy Act (NWPA): 1982 Amended: 1987 Mandated Yucca Mountain to be the nation s geologic radioactive waste repository With plans to build a second repository in the East in the future

67 Radioactive Waste Classification in the U.S. Adapted from Croff et al.

radioactive waste geologic disposal facility Has

68 Waste Isolation Pilot Plant Permian rock salt formation near Carlsbad, NM World s only operating radioactive waste geologic disposal facility Has been accepting U.S. TRU waste since 1999 Accident in 2013

69 Yucca Mountain Volcanic tuff: Porous, but low precipitation and percolation flux Strong radionuclide immobilization in rock layers

70 Two major issues with permanent geologic disposal Repository capacity limits for future nuclear power utilization Uncertainty in long-term performance of the repository

Nuclear Power Reactors. Kaleem Ahmad

Nuclear Power Reactors. Kaleem Ahmad Nuclear Power Reactors Kaleem Ahmad Outline Significance of Nuclear Energy Nuclear Fission Nuclear Fuel Cycle Nuclear Power Reactors Conclusions Kaleem Ahmad, Sustainable Energy Technologies Center Key