Download Chapter 16 * Nuclear Energy

Chapter 16 – Nuclear Energy
Alternate to Fossil Fuels
16.1 Atoms and
Radioactivity

All matter consists of
atoms

All atoms contain:

Protons ( + charge)
found in nucleus

Electrons (– charge)
orbit around the nucleus

Neutrons (neutral
charge) found in nucleus
16.1 Atoms and
Radioactivity

Atomic number equals
the number of protons
and electrons in one
atom of any element

Atomic Mass is the
amount of stuff
contained in one atom
of an element

Subtract the Atomic
number from the
Atomic mass to get the
number of neutrons
16.1 Atoms and
Radioactivity

Isotope:

Atoms of the same
element can have
different Atomic masses.

The mass changes
because nucleus has a
different number of
neutrons

Ex: Uranium has
isotope of U235 and U238
16.1 Radioactivity

Isotopes can be stable or
unstable

Unstable isotopes release
energy in the form of
protons or neutrons to
become stable

Marie Curie – Nobel
scientist, was the first
person to use
radioactive to describe
the release of energy
16.1 Radioactivity

Three kinds of energy
given off by radioactive
isotopes are

Alpha particles (2 protons
and 2 neutrons) changes
atomic mass and number
or radioactive decay

Beta particles (high speed
electrons)

Gamma rays
(electromagnetic radiation)
16.1 Radioactivity

Half-Life

The amount of time in
which half of the atoms
in a sample of
radioactive element.

Radioactive compounds
take from days to
thousands of years to
lose only one-half of
their total radioactive
energy
16.2 Reactions and
Reactors

Nuclear fission: reaction
where the nucleus of a
large atom breaks into
smaller nuclei

The fission of U235 shows
how a neutron hits the
Uranium nucleus causing
it to split into two smaller
(daughter) nuclei and
release two neutrons to hit
two more Uranium atoms
in a chain reaction
16.2 Nuclear Reactors
NUCELAR REACTORS
PRODUCE ELECTRICITY
•
FISSION OF U235
PRODUCES HEAT
•
HEAT BOILS WATER TO
MAKE STEAM
•
STEAM TURNS TURBINES
WHICH GENERATE
ELECTRICITY
Parts of a Nuclear Reactor

Fisson takes place in a REACTOR
VESSEL

The U235 in packed into FUEL
RODS

The rods are surrounded by
WATER that COOLS and
SLOWS NEUTRONS

CONTROLL RODS slow down
the reaction

The heated water produces
STEAM that turns the
TURBINES that generate
ELECTRICITY
Breeder Reactors

Breeder Reactors can PRODUCE
THEIR OWN FUEL

Uses Plutonium239 core
surrounded by stable Uranium238.

Uranium captures a neutron from
Plutonium and becomes U239
which is unstable

This CHAIN REACTION
between Plutonium and Uranium
produces energy and heat
Radioactive Waste

Nuclear power plants produce lots of
HIGH-LEVEL radioactive waste such
as fuel and control rods, coolant (water
or sodium) and the reactor vessel.

High-level waste can cause burns,
severe DNA damage, radiation sickness
and death

Hospitals, mining, contaminated
clothing from power plants are
considered MEDIUM-LOW LEVEL
radioactive waste.

Low-level waste causes DNA damage,
increased risk of cancer and other
health problems
RADIOACTIVE Waste
Disposal

HALF-LIFE of most radioactive
compounds is hundreds to
thousands of years.

U235 has a half-life of 4.5
BILLION years

Plutonium239 has a half-life of
24,000 years

They will be toxic for
generations to come.

Bury low and medium-level
wastes (Yucca Mountain –Utah)

High-level wastes are stored at
the nuclear reactors