*Production of Nuclear Energy

• Energy produced from the changes in an

unstable nucleus

• Large amount of nuclear energy can be produced

through nuclear fission and nuclear fusion.

• Nuclear energy is converted into heat energy that can be used to generate electricity

Nuclear Energy

1) NUCLEAR FISSION分裂

• Process in which an unstable and heavy nucleus is bombarded 冲击 with a neutron

• Cause it to split into

2 Lighter nuclei- Release of neutrons &

energy

Only occur in some types of

heavy and unstable nuclei

Ex: uranium-235/plutonium-

239

• The neutron produced will bombard more uranium-235

• Process repeated and result in a chain reaction

• in nuclear reactor, chain reaction is controlled by

using boron rod to absorb neutron

• The speed o f neutrons slowed down by graphite core

2) NUCLEAR FUSION

• Process in which two light nuclei combine to form a heavier, more stable nucleus together with release of a large amount of energy

• However, it produces more nuclear energy than nuclear fission

• Used to make hydrogen bomb

The heat and light energy from Sun is due to fusion of hydrogen atoms at high temperature and pressure

(Hydrogen-2)

(Hydrogen-3)

ADVANTAGES & DISADVANTAGES

Advantage DisadvantageIt produces more nuclear energy

The rate cannot be controlled

Produce less radioactive radiation

Occurs at very high temperature and pressure

*Uses of nuclear energy

*Nuclear energy is used to produce electricity in a nuclear power station.

* Is used to:Generate electrical energy propel submarine operate satellites

*ADVANTAGES OF NUCLEAR ENERGY

Not emit poisonous gas

Cheaper compared to fossil fuel

Small quantities required

Not produce lots of wastes

*DISADVANTAGES OF NUCLEAR

ENERGY

Can damage living cells

Higher maintain cost

Produce radioactive wastes

People may abuse the use of nuclear energy

EFFECTS OF RADIOACTIVE RADIATION ON LIVING THINGS

SHORT TERM

• Radiation sickness

• Bone marrow suppression

• Internal bleeding, infertility

LONG TERM

• Kill body cells• Cause mutation• Foetal

deformation• Lead to cancer• Pollution

CORRECT WAY OF HANDLING

Never handle radioactive substances with bare hands

Workers who handle radioactive

substances should wear dosimeterFrequent checking for radiation leakageRadioactive wastes are stored in

thick concrete 固结成地 or thick lead container

Radioactive wastes•Small amount of short-lived radioactivity from hospitals, research institution

Low level

•Contain higher amount of radioactivity•radioisotopes

Intermediate level

•Highly radioactive and large amount of long-lived radioactivity

High level

*Effects of radioactive rays

*Irresponsible radioactive waste disposal will pollute the environment

Exposed over short period can cause nausea and vomiting / diarrhoea

Exposed over long period can destroy body cells, causes cancer and mutation as well as abnormalities in foetus

*Proper handling of radioactive substances &

radioactive waste

1. Radioactive substances are commonly kept in thick lead containers surrounded by thick concrete.

2. The storeroom where radioactive substances are kept must be labelled with the radioactive warning symbol.

3. Radioactive waste must be kept in a lead container that is sealed tightly.

Workers in a nuclear power station must wear protective clothings and dosimeters or film badges.

*The relevant authorities must enforce existing laws to ensure that the disposal of radioactive waste is done properly.