How a Nuclear Reactor Power Plant Works
Most power plants utilize the same basic method for producing
electricity. Steam is produced and is then used to turn
a turbine which produces the electricity. The only thing
that makes a nuclear power plant unique is the method it
uses to produce the steam. Instead of burning a fossil fuel
it utilizes the tremendous amount of energy released when
atoms undergo fission. Let's take a closer look at the primary
components of a nuclear power plant. As illustrated to the
right, these components include: (1) fuel assemblies ( also
called fuel rods); (2) control rods; (3) moderator (not
illustrated); (4)reactor vessel (the kidney shaped object);
(5) containment building structure; (6)turbine/generator
and (7) cooling towers (not illustrated). Now let's take
a closer look at what some of the components are responsible
- Fuel Rods: These metal containers hold the individual
fuel pellets. Each rod holds approximately 500 enriched
uranium fuel pellets. Keep in mind that each pellet is
a cylinder about 3 cm long with a width about the size
of a pencil. Each fuel pellet is capable of producing
the same amount of energy as 1,780 pounds of coal or 149
gallons of oil or 17,000 cubic feet of natural gas!
- Control Rods: These are metallic rods (capable
of absorbing neutrons) which can be lowered or raised
between the fuel rods. Their job is to slow down or speed
up the nuclear reaction. They accomplish this by controlling
the number of free neutrons running around in the reactor
vessel. (Remember it is the slow moving neutrons which
are responsible for the nucleus being split (fission)).
To slow down the reaction the rods are lowered and absorb
the neutrons. If the reactor is moving to slow the rods
are raised, thus increasing the number of free neutrons.
- Moderator: This material (sometimes "heavy
water" is responsible for slowing down the neutrons.
In order for fission to occur
the neutrons have to be slow moving. Fast neutrons will
not be absorbed by the enriched uranium.
Illustration of A Nuclear Reactor and its'
Second Illustration of Reactor and Turbine