Nuclear Fission and How It Works in the Generation
of Electricity
Nuclear
fission (splitting) occurs when the nucleus of
an atom of U235 Uranium is bombarded with neutrons
from another source. The nucleus splits into two
smaller fragments and at the same time releases
additional neutrons. Some of these additional
neutrons will split other U235 nuclei which in
turn will release still more neutrons. This continuous
splitting is a chain reaction. One product of
a chain reaction is heat produced by the fragments
being scattered at high speed.
The
chain reaction takes place inside a containment
vessel called a reactor. Control rods, made of
a material that absorbs neutrons like a blotter,
can stop the chain reaction instantly when inserted
into the reactor fuel core.
In
the generation of electricity, the only function
of the nuclear reactor is to supply the heat necessary
to convert water into steam. Once the steam is
produced, the balance of the generating process
is exactly the same as that in a fossil fueled
generating plant.
Salem
and Hope Creek Generating Stations PSEG Nuclear’s
generating stations are located in the southern
region of New Jersey on a man-made peninsula in
the Delaware River. The plant includes a 740-acre
site surrounded by wetlands and a variety of wildlife
indigenous to the region. The complex consists
of three generating stations (Salem 1, Salem 2
and Hope Creek) and is capable of producing enough
electricity to power about three million homes.
THE
PRESSURIZED WATER NUCLEAR REACTOR – SALEM
NUCLEAR GENERATING STATION
In
a pressurized water nuclear reactor, there are
three separate and enclosed water loops. Within
the first loop, water, under pressure to prevent
boiling, flows through the reactor fuel core and
is heated by nuclear fission. The heated water
passes through the steam generator where it transfers
its heat to the water in the second loop and is
then pumped back into the reactor to be reheated.
The water in the second loop boils into steam
and rushes with great force into the turbine where
it strikes blades causing an attached shaft to
spin. The other end of the shaft spins inside
a generator, producing electricity. Within the
third loop, cooling water, drawn from an outside
source, condenses the steam after its energy is
spent. The cooling water is returned to its source
while the reconverted water is pumped back to
the steam generator.
THE
BOILING WATER NUCLEAR REACTOR – HOPE CREEK
NUCLEAR GENERATING STATION
In
a boiling water nuclear reactor, there are two
separate and enclosed water loops. Within the
first loop, water flows through the reactor fuel
core and heat generated by nuclear fission causes
it to boil into steam. The steam rushes with great
force through the steam line into a turbine. Once
in the turbine, the steam strikes blades attached
to a shaft causing it to spin.
The
other end of the shaft spins inside a generator,
producing electricity. A second water loop, carrying
cooling water drawn from an outside source, condenses
the steam when its energy is spent in the turbine.
After condensation, the reconverted water is pumped
back into the reactor vessel to start the heating
cycle again while the cooling water is returned
to its source.
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