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Nuclear energy in California has produced 36,186 million Kilowatt/hours of
electricity in 1995. The total dependable capacity of California’s nuclear-supplied power
is 5,326 megawatts, including the two operating nuclear power plants in California and
portions of nuclear plants in other states owned by California electric companies.
There are two ways to release energy from nuclear reactions: fission and fusion of
atomic nuclei. Electricity generating technologies are available, whereas fusion is still in
the early stages of research and development. Nuclear fission is the process of splitting
the nuclei of atoms, which releases energy from within those atoms. Nuclear fusion is the
process of joining, rather than splitting, these atoms with similar releases of energy.
There are several types of fission reactors in the United States but the most
common is light water reactors. The reason they are called “light water reactors” is
because normal (light) water is used to cool the reactor core; some reactors use heavy
water, which contains hydrogen atoms with an additional neutron in the nucleus.
Pressurized water reactors (PWR) and boiling water reactors (BWR) use uranium-235, a
naturally occurring radioactive isotope of uranium, as a fuel. As the nucleus of a
uranium-235 atom is hit by a neutron, it splits into smaller atoms of other elements, and
releases energy and extra neutrons. Those neutrons hit more atoms of the original
uranium-235 creating a fission chain reaction that releases more energy and neutrons.
In a PWR, water passes through the nuclear core and is heated. The power plant’s
primary circulating system passes water through the reactor core, where the water is
heated by the nuclear reaction. That water (under high temp and pressure to prevent
boiling) is passed through a steam generator, where it releases its heat to the secondary
circulating system. Water in secondary circulating system is allowed to boil, and the
resulting steam is used to drive a steam turbine-generator.
In a BWR, there is no need for a steam generator and a secondary circulating
system, as the water in primary circulating system is allowed to boil before exiting the
reactor and is then routed directly to a steam turbine-generator.
There are only two nuclear power plants out of six that are still used in California.
The first one is owned by PG&E named Diablo Canyon Nuclear Power Plant near San
Luis Obispo. The Plant has two units; the first unit is a 1,073-megawatt PWR, which
began operation in May 1985. The second unit is 1,087-megawatt PWR, which began
operation in March 1986. The second plant is owned by Southern California Edison Co.
and San Diego Gas & Electric named San Onofre Nuclear Generating Station. Unit two
of that station is a 1,070-megawatt PWR that began operation in August 1983, while unit
three is a 1,080-megawatt PWR that began operation in April 1984.
Below is a chart of nuclear power plants in California:
Nuclear Power Plants in California
Name of Plant Capacity (MW) In Service Owner
Diablo CanyonUnit 1Unit 2 1,0731,087 19851986 PG&EPG&E
San OnofreUnit 1Unit 2Unit 3 4361,0701,080 1968 – 199219831984 SCE/SDG&ESCE/SDG&ESCE/SDG&E
Humboldt Bay Unit 3 * 65 1963 – 1976 PG&E
Rancho Seco 913 1975 – 1989 SMUD
Vallecitos 30 1957 – 1967 PG&E/GE
* Units 1 and 2 are natural gas-fired thermal power plants on the same site.
There are many reasons and issues why we don’t have a lot of nuclear power
plants in California here are a few:
? Nuclear plants may not be economically feasible in the United States. No American utility has proposed to construct a new nuclear power plant since the late 1970s.
? Need for a spent fuel disposal facility and a decommissioning plan
? Use of large amounts of water for cooling purposes (if wet cooling
? towers are used)
? Biological impacts on the ocean due to thermal discharge (if seawater cooling is used)
? Designing for seismic safety
? Public safety concerns
? Transportation issues associated with the development of an emergency evacuation plan
? Changes in visual quality due to the power plant structures, including the reactor vessel containment structure, and cooling towers (if applicable)
? Potentially significant amounts of land
? Potentially significant public opposition
Nuclear power plants produce a lot of energy but they serious environmental
problems. I think that these plants are not the solution to our energy problems. I don’t see
why we can’t just go solar. But the only way we can stop the production of these plants is
to educate the people about them and the hazards of them. And that the only true way to
solve this problem is to conserve energy and go solar.