U.S. Department of Energy, Annual Energy Review 1999

4 Fig 1: Nuclear Reactors in the World By the end of 2002: 30 countries 441 reactors 16% of electricity production 7% of primary energy Source : AIEA

Types Alpha particles consist of 2 protons and 2 neutrons, and therefore are positively charged Beta particles are negatively charged (electrons) Gamma rays have no mass or charge, but are a form of electromagnetic radiation (similar to X-rays) Sources of natural radiation Soil Rocks Air Water Cosmic rays Radioactivity

Radioactivity: Nuclear changes in which unstable (radioactive) isotopes emit particles & energy Radioactive decay continues until the the original isotope is changed into a stable isotope that is not radioactive Radioactivity

cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt Relative Doses from Radiation Sources

Genetic damages: from mutations that alter genes Genetic defects can become apparent in the next generation Somatic damages: to tissue, such as burns, miscarriages & cancers Effects of Radiation

EVR3019/Nuclear_Waste.ppt

The time needed for one-half of the nuclei in a radioisotope to decay and emit their radiation to form a different isotope Half-timeemitted Uranium million yrsalpha, gamma Plutonium 23924,000 yrsalpha, gamma During operation, nuclear power plants produce radioactive wastes, including some that remain dangerous for tens of thousands of years Half-Life

Destructive power: [1] Small towns have been leveled by floods and landslides. [2] The same size town could be leveled by 1,000 tons of chemical explosives. [3] Hiroshima (quarter of a million people) was destroyed by releasing the energy in 40 kg of Uranium We know the least about the strong nuclear force.

11945 ffirst large scale use aatomic bombs were used by the US to knock Japan out of WWII ssince then attention has been given to the peaceful uses of atomic energy

 In a conventional nuclear power plant  a controlled nuclear fission chain reaction  heats water  produce high-pressure steam  that turns turbines  generates electricity.

aapproximately 20,000 times as much heat and energy is released from uranium fuels as from an equivalent amount of coal

wwhen a sufficient amount of fissionable material is brought together, a chain reaction occurs splitting atoms and releasing a tremendous amount of heat

Nuclear Fission Controlled Fission Chain Reaction neutrons split the nuclei of atoms such as Uranium or Plutonium release energy (heat)

Fusion and Fission are governed by the nuclear strong force. Fusion: two nuclei stick together (or fuse) to form a new, larger nucleus Two separate nuclei One new nucleus

Fission: When a single nucleus splits to form two smaller nuclei. Large nucleus Two smaller nuclei

Controlled Nuclear Fission Reaction cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt

breed Under appropriate operating conditions, the neutrons given off by fission reactions can " breed " more fuel, from otherwise non- fissionable isotopes, than they consume EVR3019/Nuclear_Waste.ppt

FFusion is combining together tthe atoms are fused together rather than split apart ppossibilities for nuclear fusion are much greater than those for nuclear fission

Imagine putting a hydrogen nucleus together instead of pulling it apart. We normally write this in a special way: n + p H 2 1 neutron proton Hydrogen nucleus This reads: a neutron and a proton fuse together to form a hydrogen nucleus. + np

n + p H np More energyLess energy Where did the excess energy from the left-hand-side go? There must be energy released in this process!! It comes in the form of Radiant and Thermal energy Nuclear (fusion) Energy Thermal + Radiant Energy

ffusion reactors would be fueled by deuterium, an isotope of hydrogen aavailable in almost unlimited supply in sea water

Problems: pprocess is so difficult to control that it is questionable whether commercial adaptation will ever be economically feasible

ffusion requires extreme pressure and temperatures (as high as 100 million degrees) ssuch heat was achieved by the Hydrogen bomb by first setting off a fission explosion

 Concerns about the safety, cost, and liability have slowed the growth of the nuclear power industry  Accidents at Chernobyl and Three Mile Island showed that a partial or complete meltdown is possible

Chernobyl April 26, 1986, reactor explosion (Ukraine) flung radioactive debris into atmosphereatmosphere Health ministry reported 3,576 deaths Green Peace estimates32,000 deaths; About 400,000 people were forced to leave their homes ~160,000 sq km (62,00 sq mi) contaminated > Half million people exposed to dangerous levels of radioactivity Cost of incident > $358 billion

Three Mile Island March 29, 1979, a reactor near Harrisburg, PA lost coolant water because of mechanical and human errors and suffered a partial meltdown 50,000 people evacuated & another 50,000 fled area Unknown amounts of radioactive materials released Partial cleanup & damages cost $1.2 billion Released radiation increased cancer rates.

eevacuation of preschool children and pregnant women within five miles of the plant

Photos from : The Yucca Mountain Project: /

1. Low-level radiation (Gives of low amount of radiation) Sources: nuclear power plants, hospitals & universities 1940 – 1970 most was dumped into the ocean Today deposit into landfills 2. High-level radiation (Gives of large amount of radiation) Fuel rods from nuclear power plants Half-time of Plutonium 239 is years No agreement about a safe method of storage Radioactive Waste

Radioactive Waste 1. Bury it deep underground. Problems: i.e. earthquake, groundwater… 2. Shoot it into space or into the sun. Problems: costs, accident would affect large area. 3. Bury it under the Antarctic ice sheet. Problems: long-term stability of ice is not known, global warming 4. Most likely plan for the US Bury it into Yucca Mountain in desert of Nevada Cost of over $ 50 billion 160 miles from Las Vegas Transportation across the country via train & truck

Yucca Mountain EVR3019/Nuclear_Waste.ppt

““The odds of an American dying from a nuclear power accident are 300 million to one.”

Fissile Resources Nuclear Reactor Electricity Intermediate/Low Level Waste Conversion Enrichment Uranium Extraction Fuel Fabrication Interim Storage Encapsulation Waste Disposal High Level Waste Spent Fuel Long-Term Nuclear Energy Depends on an Advanced Nuclear Fuel Cycle ReprocessingRecycle Recycling TRU In Adv. Reactor Fissile Waste 235 U/ 233 U / 239 Pu Electricity & H 2 Multiple Reactors

The Nuclear Fuel Cycle including High level vs. low level Nuclear Waste