Nuclear Energy

Abaricia, Emmanuel Costales, Roseanne Eniceo, Raniel Jacinto, Stephanie Morenos, Jan Monil Villanueva, Kirby Nuclear Energy

Introduction Nuclear Power -is any nuclear technology designed to extract usable energy from atomic nuclei via controlled nuclear reactions. -nuclear fission -nuclear fusion -radioactive decay

Introduction Origin Neutron -James Chadwick (1932) Nuclear fission -Enrico Fermi (1934) in Rome, when his team bombarded uranium with neutrons.

Introduction Origin Nuclear fission -(1938) German chemists Otto Hahn and Fritz Strassmann, along with Austrian physicists Lise Meitner and Meitner's nephew, Otto Robert Frisc conducted experiments with the products of neutron-bombarded uranium.

Introduction Origin Chicago Pile-1 -first man-made reactor created by Fermi and Szilard on December 2, 1942 in the United States. -became part of the Manhattan Project, which built large reactors at the Hanford Site to breed plutonium for use in the first nuclear weapons.

Introduction Origin Arco Reactor -Electricity was generated for the first time on December 20, 1951 at the EBR-I (Experimental Breeder Reactor I) experimental station near Arco, Idaho, which initially produced about 100 kW. -was also the first to experience partial meltdown in 1955

Introduction Early Years of Nuclear Power Calder Hall -world's first commercial nuclear power station located in Sellafield, England. -was opened in 1956 with an initial capacity of 50 MW (later 200 MW) Shippingport Reactor -the first commercial nuclear generator to become operational in the United States at Pennsylvania on December,1957.

Introduction Early Years of Nuclear Power USS Nautilus (SSN-571) -first nuclear-powered submarine was put to sea in December 1954. SM-1 Nuclear Power Plant - located at Ft. Belvoir, Va., was the first power reactor in the US to supply electrical energy to a commercial grid (VEPCO), in April 1957, beforeShippingport.

Introduction Use As of 2005 -nuclear power provided 2.1% of the world's energy. -15% of the world's electricity, with the U.S., France, and Japan together accounting for 56.5% of nuclear generated electricity.

Introduction Use In 2007 -nuclear power's share of global electricity generation dropped to 14%. According to the International Atomic Energy Agency, the main reason for this was an earthquake in western Japan on 16 July 2007, which shut down all seven reactors at the Kashiwazaki-Kariwa Nuclear Power Plant.

Uranium Exploration Current economic uranium resources will last for over 100 years at current consumption rates, while it is expected there is twice that amount awaiting discovery. With reprocessing and recycling, the reserves are good for thousands of years. Worldwide around 5.5 million tonnes of uranium that could be economically mined has been identified. The figure is up by 17%

Uranium Exploration Uranium averages about 2.8 parts per million of the earth's crust. It is more abundant than gold, silver or mercury about the same as tin and slightly less abundant than cobalt, lead or molybdenum. Also occurs at oceans at a lesser concentration

Reasonably Assured Resources plus Inferred Resources, to US$ 130/kg U, 1/1/05, from OECD NEA & IAEA, Uranium 2005: Resources, Production and Demand.

Mining and Processing Uranium ores are usually obtained by open cut mining

Mining and Processing At conventional mines, the ore goes through a mill where it is first crushed. crushing breaks up the largest pieces followed by fine crushing to reduce the material to small pieces of about 20 mm and less. The 'fine' ore is then ground in water to produce a slurry of fine ore particles suspended in the water. The slurry is leached with sulfuric acid to dissolve the uranium oxides.

Mining and Processing Most of the ore however remains undissolved in the leaching process, and these solids or 'tailings' are then separated from the uranium-rich solution, usually by allowing them to settle out. The liquid containing the uranium is filtered and the uranium then separated by ion exchange.

Mining and Processing Finally the uranium is recovered in a chemical precipitate which is filtered and dried to produce a uranium oxide concentrate. It is then packed into 200 liter steel drums which are sealed for shipment.

Wastes on Mining and Milling Solid waste products from the milling operation are pumped as a slurry to a tailings dam. These wastes comprise most of the original ore and they contain most of the radioactivity in it. In particular they contain radium, present in the original ore.

2.2 Nuclear Energy Extraction -Fuel Conversion ,[object Object]

UF6 (149 deg C) Enrichment Process

Centrifuge Isotopes Uranium 235 and 238The uranium enrichment process increases the concentration of U-235 to the amount needed for use in reactor fuel. Source: http://www.nrc.gov/materials/fuel-cycle-fac/ur-enrichment.html

Fission Reaction: Schematic diagram of a fission chain reaction. Based roughly on the illustration in the Smyth Report (1945) Source: <http://en.wikipedia.org/wiki/File:Fission_chain_reaction.svg>

Chain Reaction Fig 1. Neutrons produced by the first fission event collide with other nuclei, causing their fission and the production of more neutrons to continue the process . Source: Hashemi, Ab. Nuclear Energy. <http://www.engr.sjsu.edu/ahashemi/Nuclear%20Energy.pdf>

Reactor Core: ,[object Object]

Control rods -Moderator Several different proposals call for placing enrichment capabilities under multinational control to assure supplies of nuclear fuel and reduce proliferation risks. Fuel rods ready for inspection at a fuel fabrication facility. (Photo: D. Calma/IAEA) Source: Top Stories. “IAEA Welcomes US Contribution of $50 million to Nuclear Fuel Bank.” International Atomic Energy Agency, WagramerStrasse 5, A-1400 Vienna, Austria <http://iwww.iaea.org/nuclear_energy_fuel_banks>

Summary of Reactor Operation Figure 1: A Reactor Operation with Controlled Fission Source: Hashemi, Ab. Nuclear Energy. <http://www.engr.sjsu.edu/ahashemi/Nuclear%20Energy.pdf>

Disposal of Waste Nuclear fuel cycle produces radioactive wastes on each cycle. There are proven technologies to dispose the radioactive wastes safely. The main objective of managing and disposing these wastes is to protect the people and the environment. This means isolating or diluting the waste so that the rate or concentration of any radio nuclides returned to the biosphere is harmless. There are different types of radioactive wastes. They can be differentiated according to their level of concentration.

Type of Radioactive Waste Exempt wastes & very low level waste Low-level waste Intermediate-level waste High-level waste

Waste Treatment and Conditioning of Nuclear Wastes The aims of treating and conditioning processes are to be able to minimize the volume of waste requiring management via treatment processes and to be able to reduce the potential hazard of waste by conditioning it into a stable solid form that immobilizes it and provides containment to ensure that the waste can be safely handled during transportation, storage and final disposal. The choice of process would depend on the type and the level of activity of the waste.

Incineration Compaction Cementation Vitrification

Disposal Options Near-surface disposal Deep geological disposal

Handling and Storage Spent Fuel- generates intense heat and radiation -stored underwater for 10 to 20 years before being sent for reprocessing ,[object Object],[object Object]

Nuclear Energy

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Nuclear Energy