Nuclear

Chemistry

Nuclear

ChemistryPart IIPart IIPart IIPart II“The discovery of nuclear reactions need not bring about the destruction of mankind any more than the discovery of matches”

-Albert Einstein

More Nuclear More Nuclear ReactionsReactions

More Nuclear More Nuclear ReactionsReactions

A. Nuclear Fission – the splitting of a nucleus into smaller fragments (the splitting is caused by bombarding the nucleus with neutrons). This process releases enormous amounts of energy.

A nuclear chain reaction is a reaction in which the material that starts the reaction (neutron) is also one of the products and can be used to start another reaction.

B. FissionB. FissionB. FissionB. Fissionchain reaction - self-propagating reactioncritical mass -

mass required to sustain a chain reaction

C. Nuclear PowerC. Nuclear PowerC. Nuclear PowerC. Nuclear PowerNuclear Reactors use controlled – fission

chain reactions to produce energy or radioactive nuclides.

C. Nuclear PowerC. Nuclear PowerC. Nuclear PowerC. Nuclear Power

a. shielding – radiation absorbing material that is used to decrease exposure to radiation.

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b. fuel – uranium is most often used

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c. control rods – neutron absorbing rods that help control the reaction by limiting the number of free neutrons

Steam

C. Nuclear PowerC. Nuclear PowerC. Nuclear PowerC. Nuclear Powere. coolant – water acts as a coolant and transports

heat between the reaction and the steam turbines to produce electric

current

C. Nuclear PowerC. Nuclear PowerC. Nuclear PowerC. Nuclear Power

C. Nuclear PowerC. Nuclear PowerC. Nuclear PowerC. Nuclear Power

Nuclear Power Plants produce a great deal of energy, the current problems with nuclear power plants include environmental requirements, safety of operation, plant construction costs, and storage and disposal of spent fuel and radioactive waste.

D. Atomic BombD. Atomic BombD. Atomic BombD. Atomic Bomb

chemical explosion is used to form a critical mass of 235U or 239Pu

fission develops into an uncontrolled chain reaction

FusionFusionFusionFusionA. combining of two nuclei to form one nucleus of larger mass,

usually very small atoms of hydrogen and helium are used. B. thermonuclear reaction – requires temp of 40,000,000 K to

sustain1 g of fusion fuel =

20 tons of coal

HH 31

21

FusionFusionFusionFusion

C. Sun/Stars – four hydrogen nuclei combine at extremely high temperatures and pressures to form a helium nucleus – this is a fusion reaction.

B. FusionB. FusionB. FusionB. Fusion

Hydrogen Bomb- uncontrolled fusion reactions of hydrogen are the source of energy for the hydrogen bomb. Hydrogen bombs generate a great deal more of energy then an atomic bomb.

B. FusionB. FusionB. FusionB. Fusion

Fusion as a Source of Energy: Fusion reactions generate a great deal more energy and their products are less harmful then fission reactions.

Research is being done to try to use fusion instead of fission, there are a few problems: the temperature required is so high no known material can withstand the temperature.

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Fusion Reactors (not yet sustainable)

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Fusion Reactors (not yet sustainable)

Tokamak Fusion Test Reactor

Princeton University

National Spherical Torus Experiment