10) Notes 3 Power-Fis-(Fus)-JR

siennatearfulUrban and Civil

Nov 25, 2013 (3 years and 11 months ago)

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Nuclear

Power Plants

Nuclear Power Plant

Turbine and Generator


Spinning
turbine blades
and generator

Boiling water

Steam

Nuclear Energy Powers

1 in 5 U.S. Homes and
Businesses


Nuclear Energy Comes

From Fission


Uranium atom

Neutrons

Spit atoms

Heat

Splitting Atoms Releases
Neutrons, Making Heat

Neutrons

Heat Produces Steam,
Generating Electricity


Heat

Steam
produced

Steam

Turbine

Generator

Electricity

Nuclear Fission


The process of splitting a larger
atomic nucleus into two smaller
nuclei by bombarding it with
neutrons. This process releases
energy that is stored in the nucleus
.

n

1

0

+

U

235

92

Kr

91

36

n

1

0

Ba

142

56

+

+

+

Energ
y

3

Uranium Is Mined and Refined

Uranium Ore


啲慮極洠
hexafluoride


䝡猠


卯汩S



Enrichment Concentrates
the Uranium Isotope




Our current nuclear power plants run on
fission

They use the
U
-
235

isotope of
Uranium

as fuel. Most uranium in natural
ores exists in as
U
-
238

Only U
-
235 is
fission
able. Processed uranium must be
“enriched” in centrifuges to concentrate the
U
-
235. Uranium used in reactors is
4
-
5
%
U
-
235. Uranium used in nuclear weapons
must be
90
% U
-
235.

Uranium Is Encased in Solid
Ceramic Pellets



Fuel Rods Filled With Pellets Are
Grouped Into Fuel Assemblies



The fission process
can continue until all
of the available “big
atoms” are gone. This
is a
chain reaction.

Reactions must be
slowed down with
neutron
-
absorbing
control

rods.

Controlling the Chain Reaction


Control rods

Fuel

Assemblies

Withdraw control rods,

reaction increases

Insert control rods,

reaction decreases

Boiling Water Reactor


Steam

Pressurized Water Reactor

Safety Is Engineered Into
Reactor Designs


Containment Vessel

1.5
-
inch thick steel



Shield Building Wall

3 foot thick reinforced concrete


Dry Well Wall

5 foot thick reinforced concrete


Bio Shield

4 foot thick leaded concrete with

1.5
-
inch thick steel lining inside and out


Reactor Vessel

4 to 8 inches thick steel


Reactor Fuel


Weir Wall

1.5 foot thick concrete