Turning Rocks into Gold (Electric gold, that is) A miracle of modern alchemy Presented at Seminar on Canada’s Nuclear Technology University of Ontario institute of Technology October 15, 2009 Society

Potential Energy in the Universe Hydrogen fusion (as well as other nuclei) – in our sun and all visible stars Uranium fission Uranium fission – both natural and man-made Radioactive decay – energy from our primordial “big bang” via supernovae Gravitation – drop a pencil, release some energy. Pick it up, store some energy (that energy came from the sun via your food) Environment

Uranium? It is radioactive – Uranium-238 decays by alpha particle emission to thorium-234; it eventually transforms into lead-206 Uranium-238 also splits by spontaneous fission Uranium-238 also splits by spontaneous fission – 2 or 3 neutrons are released by the fission fragments The fission and decay of natural uranium, thorium and potassium releases (in the whole earth) about 38 million megawatts The fission and decay of natural uranium, thorium and potassium releases (in the whole earth) about 38 million megawatts – This radioactivity heats the core of the earth geothermal energy leaving the earth’s surface comes almost entirely from this radioactive decay Science

The First Fission Reactors (1.7 Billion years ago in Gabon, West Africa – 15 discovered) Steam Water Uranium-Bearing Zone Science Cross section of Geological Strata

Nuclear Fission When two light nuclei fuse (join), mass is converted to energy This happens in the sun When a heavy nucleus fissions (splits), mass is converted to energy This happens in a nuclear reactor This happens in a nuclear reactor When gasoline burns, mass is converted to energy This happens in your car’s engine E = mc 2 Science

What are some uses for Uranium? We use heat from fission to make steam for a steam turbine We use heat from fission to make steam for a steam turbine – more than half Ontario’s electricity comes from uranium We have used it to make nuclear bombs – and nations have formed a strong international organization (IAEA) to guard against use for weapons We have used it to make attractive glass – until recently some glass-makers added uranium to glass. Such uses are now banned, to protect our health We use it as ballast in B747 aircraft Technology, society and environment

Energy of Fission It could be called “Femtopower”  a nucleus is very small – uranium nucleus diameter is 16 femtometers ( meters) It takes 31 billion fission reactions to release one watt- second (one joule) of energy. chain reaction – Fission is sustained at a constant rate by neutrons emitted during earlier fissions, in a chain reaction – The fragments (fission products) are at first highly radioactive, then rapidly decay to stable elements boil water – Most of the energy appears as heat in the fuel pellets. It is this energy that we use to boil water at high temperature and pressure Science

Energy Flows Thermal energy (fuel) Thermal energy (water) Mechanical Energy (turbine) Conduction Boiling Fission Potential Energy in the atomic nucleus Electrical energy (generator) Induction Your lights, toaster, stove Transmission Losses to environment Technology, society and environment Losses to environment Engineering

Nuclear Fuel (pellet) Uranium dioxide – ceramic, melting point 2800 C – It is slightly radioactive – One fuel pellet releases enough energy to make 2 slices of toast every minute for a year (about 1 million slices) Over 6 million fuel pellets are loaded in each Darlington reactor, in 5760 fuel bundles – Darlington produces 3524 megawatts of electricity from 4 reactors The world’s supply of nuclear fuel is inexhaustible Engineering Technology Energy in the atomic nucleus Thermal energy (fuel)

The Magnitude of the Hazard Varies HAZARD OF NUCLEAR FUEL BEFORE LOADING REACTOR OPERATION USED FUEL COOLDOWN About 7-8 orders of magnitude About 300 years Science, environment Used fuel decays rapidly at first, then more slowlyUsed fuel decays rapidly at first, then more slowly The “last nucleus” does not decay for a very long timeThe “last nucleus” does not decay for a very long time Radioactive hazard returns to the original level after about 300 yearsRadioactive hazard returns to the original level after about 300 years

Making Electricity Heat energy is pumped in high pressure water to the boilers Water is then boiled to produce steam to drive a steam turbine Induction transforms mechanical energy into electrical energy Electricity is transmitted to you, the customer, all within less than 30 seconds after fission Electricity is transmitted to you, the customer, all within less than 30 seconds after fission About 70% of the total fission energy is lost to the environment Thermal energy (water) Mechanical energy (turbine) Electrical energy (generator) Losses to environment Engineering

Nuclear Reactor Designs Most of today’s Nuclear Plants (436) use Water Reactors – Pressurized water reactor (PWR) – Boiling water reactor (BWR) – Pressurized heavy water reactor (PHWR) These designs are being modified as technology improves – Under construction: 50 – On order or planned: 137 – Proposed: 295 Future designs are known as “Generation 3 or 4” – Some of these power plants will use fast reactors (FBR) Engineering Society

A Canadian Dream for the Future Around the year 2100? DUPIC Plant CANDU PWR BWR Oxide Fabrication Plant Reprocessing Plant U + Pu + f.p. Disposal U238 Pu U/Th Waste Fresh Fuel Fresh Fuel FBR REPROC. + FAB. PLANT Fission products U CANDU PHWR Storage Society

Storing Electricity? – Transform It! Base Load Intermediate Load Intermediate - reservoir limited Tops Peak Frequency Control Engineering Nuclear energy supply range Daily Energy Storage

Fuel -- A Small Part of Electricity Cost * Today, the uranium price is about $90 per kilogram – At this price we have enough to fuel 6000 thermal reactors for > 40 years – As market price increases the amount of “ore” (at a lower grade) increases – The uranium fuel contribution to electricity cost is negligible today – If the uranium price were half the price of gold, the price of electricity from thermal reactors would double – If the uranium price were half the price of gold, it would be very profitable to extract uranium from seawater 4000 years using thermal reactors (PWR, BWR, PHWR) or at least 600,000 years using fast reactors (FBR) – Seawater is known to contain enough uranium to supply 100% of the world’s energy for 4000 years using thermal reactors (PWR, BWR, PHWR) or at least 600,000 years using fast reactors (FBR) – Thorium is more abundant – Thorium (another potential fuel) is more abundant than uranium in the earth’s crust * D.Lightfoot et al, “Nuclear Fission Energy is Inexhaustible”, Proceedings of the first Climate Change Technology Conference, Engineering Institute of Canada, Ottawa, May 2006 Science

It’s Not all Sweetness and Light Fission must be controlled at a constant rate High pressure pipes must hold water Heat losses must not damage the environment Radiation must be contained Fission products must be safely stored in the long term Fission products (the ashes of fission) must be safely stored in the long term Electricity must be affordable Technology Today, we only use 1% of the energy in the fuel

Nuclear Energy is: AvailableSafeInexhaustible