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Nuclear Power

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.

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