Nuclear Power. by Adam, Ridgewell, Alex, James,and Rachel

Transcription

1 Nuclear Power by Adam, Ridgewell, Alex, James,and Rachel

2 How Nuclear Power Works

3 The Pros and Cons of a Nuclear Power Plant Pros: Lower CO2 emissions than traditional coal burning energy production (roughly ⅙ less) Extremely efficient/capable of producing immense sums of energy. Low operation costs once a plant is constructed Potential for waste recycling programs (though costly) Nuclear disasters thus far have been at the fault of humans or natural disaster, rather than system failure Nuclear technology is readily available, thoroughly developed, and efficient, compared to other energy sources that still struggle to produce on a larger scale. Cons: Large initial investment, largely due to safety precautions High subsidies needed for operation and construction (subsidies which could be used in other energy areas) Uranium a nonrenewable energy source (yet research is open for other sources, such as Thorium) Produces large quantities of toxic/radioactive waste that remain intact for hundreds of thousands of years Potential for accidents with immense consequences (see Chernobyl, Fukushima, etc.)

4 Three Mile Island: America s Worst Nuclear Power Plant Accident What happened? March 29, 1979 The three mile island nuclear plant near Harrisburg, PA lost its coolant water because of a series of mechanical failures and human operator errors. Radioactive core became partially uncovered and about half of it melted and fell to the bottom of the reactor Unknown amounts of radioactivity had escaped into the atmosphere About 50,000 people were evacuated and about 50,000 people fled on their own Various studies have shown no increase in cancer rates from radiation released by the accident, but there is controversy over this issue because of insufficient data

5 Three Mile Island: America s Worst Nuclear Power Plant Accident Why is this significant? The TMI accident lead to improved safety regulations for U.S. nuclear power plants and improved emergency and evacuation plans. There have been no notable U.S. accidents since TMI

6 Chernobyl: The World s Worst Nuclear Power Plant Accident What happened? April 26, 1986 A series of explosions in one of the reactors in a nuclear power plant in the Ukraine blew the massive roof off of a reactor building. The reactor partially melted down, and its graphite moderator caught fire and burned for 10 days, releasing more than 100 times the amount of radiation generated by the atomic bombs dropped by the United States on Japan during World War II. A radioactive cloud spread over Belarus, Russia, Ukraine, and Europe and eventually encircled the planet.

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8 Chernobyl: The World s Worst Power Plant Accident Why is this significant? In 2008, after 22 years, areas of the Ukraine and northern Europe are still dangerously contaminated with radioactive materials and a result of the accident The Chernobyl disaster was caused by poor reactor design, and like most things, by human error, and this had serious consequences. By 2005, 56 people had died prematurely from exposure to radiation released by the accident The Russian Academy of Medical Sciences estimated the eventual death toll at 212,000. After the accident, some 350,000 people had to abandon their homes because of radioactive contamination. In addition to fear about longterm health effects such as cancers, many of these victims continue to suffer from stress or depression In parts of the Ukraine, people still cannot drink fresh water or eat locally produced fruits, vegetables, fish, meat or milk. In contaminated areas, the frequency of birth defects and mental retardation in newborns has increased There are also higher incidences of thyroid cancer, leukemia, and immune system abnormalities in children exposed to radioactive fallout. Chernobyl taught us a hardhitting lesson: A major nuclear accident, no matter where it happens, has effects that reverberate throughout much of the world.

9 Fukushima: Japan s Worst Nuclear Power Plant Accident What happened? March 11, 2011 Following a major earthquake, a 15 meter tsunami disabled the power supply and cooling of three Fukushima Daiichi reactors, causing all three radioactive cores to melt in the first three days. Some 300,000 people evacuated the area 15,884 people died due to the earthquake and tsunami 1600 deaths were related to the evacuation or its consequences

10 What Do We Do With a Decommissioned Nuclear Power Plant?

11 Tactics for Preventing Radiation Poisoning The International Atomic Energy Agency has 3 decommissioning strategies: Immediate Dismantling Faculty is removed from regulatory control & dismantling activities happen quickly, could be done within 5 years, and the lot can be reused for other purposes Safe Enclosure Faculty placed into a safe storage until dismantling occurs between 40 to 60 years later Entombment Centralizing the place where radiation is being emitted and encasing it in concrete

12 What problems surround what we do or should do with radioactive wastes? The transportation of this waste poses an unacceptable risk to people and the environment. Nuclear wastes are hazardous for tens of thousands of years. This clearly is unprecedented and poses a huge threat to our future generations. The main objective in managing and disposing of radioactive (or other) waste is to protect people and the environment. This means isolating or diluting the waste so that the rate or concentration of any radionuclides returned to the biosphere is harmless. To achieve this, practically all wastes are contained and managed some clearly need deep and permanent burial, which can be difficult depending on the location. Even if put into a geological repository, the waste might emerge and threaten future generations. Manmade radiation differs from natural radiation. The waste should be disposed of into space.