NUCLEAR ENERGY AND THE ENVIRONMENT
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This document discusses nuclear energy and its various aspects. It begins by describing the first nuclear reactor, which was a group of bacteria in Africa. It then explains key concepts like nuclear fission, the splitting of uranium atoms, and the three types of uranium found in nature. The document also covers radiation and its health effects, radioactive decay and half-life, and the different types of nuclear radiation. It discusses issues like nuclear waste and accidents at power plants. In general, the document provides a broad overview of nuclear energy topics.
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NUCLEAR ENERGY AND THE ENVIRONMENT
- 1. BY: LILY ROSEMARY L. MASILANG
- 2. NUCLEAR ENERGY FIRST NUCEAR REACTOR Group of bacteria (algal mat) in Oklo Gabon Africa
- 3. NUCLER ENERGY Is the energy of the atomic nucleus. Nuclear fission Nuclear fusion
- 4. NUCLER ENERGY Nuclear fission Is the splitting of atom’s nucleus into smaller fragments. Requires uranium as fuel.
- 5. NUCLER ENERGY Fission reactions 1942 led to the development of uranium as: oExplosives oSource of energy (electricity)
- 6. NUCLER ENERGY 3 types of uranium occurring in nature Uranium-238 Uranium-235 Uranium-234
- 7. NUCLER ENERGY RADIATION Cannot see it, smell it, or feel it. Causes health problem
- 8. NUCLER ENERGY Radioisotope A form of chemical element that spontaneously undergoes radioactive decay.
- 9. NUCLER ENERGY Half life The time required for one half of a given amount of isotope to decay to another form. Short half life, present for brief time and rapid rate of change Long half life, present for a long period of time and slow nuclear transformation.
- 10. NUCLER ENERGY
- 11. NUCLER ENERGY Kinds of nuclear radiation Alpha particles consist of two protons and tow neutrons (a helium nucleus) and have the greatest mass of the three types of radiation.
- 12. NUCLER ENERGY Beta particles are electrons and have a mass of 1/1840 of proton. Neutrino - is a particle with no rest mass
- 13. NUCLER ENERGY Gamma rays Most penetrating type of radiation Emitted from the isotope
- 15. NUCLER ENERGY RADIATION ON HUMAN HEALTH Alpha radiation is most toxic or dangerous when inhaled or ingested. Beta radiation is intermediate in toxicity, although most beta radiation is absorbed by the body when a beta emitter is ingested. Gamma emitters are toxic and dangerous inside or outside the body, but when they are ingested, some of the radiation passes outside the body.
- 16. NUCLER ENERGY 7 PARTS OFTHE BODYTHAT RADIATION AFFECTS THE MOST: Hair Brain Thyroid Blood streams Heart Gastrointestinal tract Reproductive tract
- 17. NUCLER ENERGY BURNER REACTORS Use to consume more fissionable materials than they produce. The same function as the boiler that produces the heat in coal-burning or oil- burning power plants.
- 18. NUCLER ENERGY MELTDOWN A nuclear accident in which the nuclear fuel becomes so hot that it forms a molten mass that breached the containment of the reactor and contaminate the outside environment with radioactivity.
- 20. NUCLER ENERGY BREEDER REACTORS A reactor that converts fertile nuclei to fissile nuclei faster than the rate of fission.
- 21. NUCLER ENERGY FUSION Fusion involves combining light elements to form a heavier element.
- 23. NUCLER ENERGY PROBLEMS WITH NUCLEAR POWER Produced radioactive waste materials. Site selection and construction were extremely controversial Proper handling, transporting and disposal of waste Decommissioning or modernization It is also risky to supply nuclear reactors because of terrorism and the irresponsible persons in the government.
- 24. NUCLER ENERGY DISADVANTAGES of FUSION Use of toxic materials Strong magnetic field Microwaves used in containing plasma Short-lived radiation emitted from the reactor vessel. ADVANTAGES of FUSION Land use and transportation Little radioactive waste product
- 25. NUCLER ENERGY EFFECTS OF RADIOISOTOPES emitting radiation Entering the normal pathways of mineral cycling and ecological food chains ATOMIC FALLOUT Cause by the explosion of a nuclear atomic weapon Environmental problem of the 1950’s
- 27. NUCLER ENERGY RADIATION DOSES (mSv is milliSievert) 5000 mSv-lethal 1000-2000 mSv-can cause health problems 500 mSv-psychological damage 50 mSv-allowed dose of radiation for workers per year
- 28. NUCLER ENERGY NUCLEAR POWER PLANT ACCIDENTS Three Mile Island March 28, 1979
- 30. NUCLEAR ENERGY Chernobyl before the accident Chernobyl after the accident
- 31. NUCLER ENERGY Mutation (Chernobyl accident)
- 32. NUCLER ENERGY RADIOACTIVE WASTE MANAGEMENT Low level radioactive waste With low concentration or quantities of radioactivity
- 33. NUCLER ENERGY High level radioactive waste Extremely toxic, and a sense of urgency surrounds its disposal as the total volume of spent fuel accumulates
- 34. NUCLER ENERGY Nuclear Waste Policy Act of 1982 Yucca mountain site in southern Nevada is the evaluated site for the disposal of high energy radiation waste.
- 35. NUCLER ENERGY THE FUTURE OF NUCLEAR ENERGY Nuclear energy as a power source of electricity Nuclear power plants should be smaller and safer Alternative energy would be supplying more of the nation’s energy needs
- 36. THANKYOU!!!!
Notes de l'éditeur
- Natural nuclear reactors were present on earth 1.8 billion years ago. *constructed nonexplosive, naturally controlled nuclear reactor that ran for millions of years. *the bacteria had the capacity to concentrate uranium from nonunranium-bearing water beyond the critical mass necessary to initiate and maintain the nuclear chain reactions that today occur in nuclear power plant.
- There are two processes can be used to release that energy to do work. (refer to next slide)
- *Controlled nuclear fission reactions takes place within commercial nuclear reactors to produce energy. Nuclear energy from fission may be considered a non renewable energy source. It is an alternative to fossil fuels, and it is non-renewable because it requires uranium as fuel. Uranium is a geologic resource in limited supply. However, worldwide uranium reserves are sufficient to supply nuclear energy at present rate of consumption with present technology through the next century.
- 1942- first human-controlled nuclear fission, One kg of uranium oxide produces heat equivalent to approximately 16 tons of coal making uranium an important source of energy in the US and the world.
- 238- accounts for approximately 99.3% of all natural uranium, 235-which makes about 0.7% and 234-which makes about 0.005% Uranuim 238 and 234 are two naturally radioactive isotopes of uranium. Uranium 235 is the only naturally occurring fissionable materials and therefore is essential to the production of nuclear energy.
- Each radioactive isotope has its own unique and unchanging half life. For example, the half life of uranium 235 is 700 million years, radioactive carbon-14 (5570 years which is in the intermediate range) and radon-222 has a relatively short half life of 3.8 days. Another is polonium-218 has a half life of 3 minutes. Radioisotopes with long half lives have a less intense and slower initial rate of nuclear transformation but may be hazardous for a much longer time.
- Alpha particles consist of two protons and tow neutrons (a helium nucleus) and have the greatest mass of the three types of radiation. Beta particles cause alpha particles to have relatively high mass, the particles do not travel far. To cause damage to living tissues cells and, the alpha particles should be very close to the cell.
- Beta particles When beta particles decay another particle if formed. Neutrino is a particle with no rest mass Beta particles travel farther through air but are blocked by moderate shielding, such as thin sheet of metal or block of wood.
- Gamma rays are similar to X ray but more energetic and penetrating. Gamma rays travel the longest average distance of all type of radiation and can penetrate thick shielding. Gamma rays interact with anything along their path.
- But because alpha radiation is stopped within a very short distance by living tissue, much of the damaging radiation is absorbed by the tissue. On the other hand, when alpha emitting isotopes are stored in a container, they are relatively harmless. if the particles are swallowed, inhaled or absorbed through open wounds, the effects of alpha radiation on humans can indeed be quite severe. Can cause cancer (swallowed, inhaled or absorbed) kidney damage (uranium in water) DNA damage.
- 1. Causes hair loss 200 rems or higher) 2. Damage to brain cell, can cause seizure and death (5000 rems or higher) 3. Radioactive iodine can destroy the part of the thyroid but can be reduced by taking potassium iodide 4. Blood lymphocyte cell is reduced leaving the body more susceptible to infections and diseases (100 rems) and long term exposure (about 10 years) to radiation can cause leukaemia and lymphoma 5. Damages small blood vessel and can cause heart failure and death (1,000 to 5,000 rems) 6. Damage to intestinal tracts will cause nausea, bloody vomiting and diarrhea (200 rems or more) 7. Cause of being sterile. (As low as 200 for long term exposure)
- This is essentially a burner reactor with the advantage that it can reduce waste management problems by consuming plutonium and long-life highly radioactive actinides while generating electricity.
- Upper picture is an image taken in the Fukushima nuclear power plant meltdown on March 11 2011
- A nuclear reactor that can utilize 40 to 70% of its nuclear fuel. This can extend our nuclear fuel reserves as well as our uranium reserves. Experiments with breeder reactors have not been very because the electricity produced has been considerably more expensive than that produced from burner reactors. Breeder reactors are more expensive to engineer and build. This also give arise to plutonium-239, a major ingredient of nuclear weapon. On the other hand, both burner and breeder reactors may become obsolete and be replaced by fusion reactors in the next century.
- As fusion occurs, heat energy is released. Nuclear fusion is the source of energy in our sun and other stars. Several conditions are necessary for fusion to take place. (1) there must be an extremely high temperatures (approx. 100 Degrees Celsius) (2) the density of the fuel must be sufficiently high. Stripping of electrons forming PLASMA (3) the plasma must be confined for a sufficient time to ensure that the energy released by the fusion rection exceeds the energy supplied to maintain the plasma. PLASMA is a an electrically neutral material consisting a positively charged nuclei, ions, and negatively charged electrons.
- From mining and processing of uranium to controlled fission, the reprocessing of spent nuclear fuel, the decommissioning of power plants and the disposal of radioactive waste. Disposal (1) low energy waste, shallow burial (2) high energy waste, isolated
- Uranium mines and mills produced radioactive waste materials that can pollute the environment. The environmental review is expensive and extensive, often centering on hazard related to probability of such events as earthquakes damaging the plant. People are concern about the site because it is the most visible part of the cycle. It is also the site of past accidents; including partial meltdowns that have realeased harmful radiation into the environment. Waste disposal is a controversial part of the nuclear cycle because no one wants a nuclear waste disposal facility nearby. Decommissioning is expensive. Also we have a little experience with this.
- Using materials like lithuim
- Top-right picture is the image of the mushroom smoke emitted by the atomic bomb dropped in Nagasaki, Japan during the World War II. Down-left picture a of bomb disposal/test in a deserted area.
- Health problems including vomiting, fatigue, potential abortion of pregnancies of less than 2 months’ duration and temporarily sterility in males.
- One of the most dramatic events in the history of US radiation pollution. Three mile island power plant near Harrisburg, Pennsylvania. Malfunction of nuclear power plant resulted in a release of radioisotope into the environment as well as intense radiation release within one of the nuclear facilities. Plume exposure was estimated 1 mSv required to cause acute toxic effects. On the third day, 12 mSv/hour was measured at ground level near the site. American only receives about 1.5 mSv/year.
- April 26, 1986, the soviets announced that there had been an accident at their nuclear power plant at Chernobyl. This was the first notice to the world that worst accident in the history of nuclear power generator had occurred. 237 confirmed cases of acute radiation sickness and 31 people died of radiation sickness. 3 billion people in the northern hemisphere receive varying amount of radiation from Chernobyl.
- A child who is born with disability (mutation) due to the exposure of his parents with radiation. A pig who did not properly developed
- LLW- includes, chemical or residual solutions from chemical processing, solid or liquid plant waste, sludges, and acids. Has been buried and monitored in near-surface burial areas in which the hydrologic and geologic conditions were thought to severely limit the migration of radioactivity.
- Advocates argued that Nuclear power is safer than other sources of energy. They say that the number of additional deaths caused by pollution resulting from burning of fossil fuels is much greater than the number of lives lost through nuclear accidents.