Unit 10: Lesson 5 - Fission and Fusion Reactions

______________ is a nuclear reaction in which several smaller, very light nuclei combine to form a single, heavier, more stable nucleus.

Nuclear fusion

____________ water in the reactor cools the reactor and also serves as a moderator to control the chain reaction.

Pressurized

nuclear fission

a nuclear reaction in which a heavy, unstable nucleus splits into two or more smaller, stable nuclei

nuclear fusion

a nuclear reaction in which several very light nuclei combine to form a single, heavier, more stable nucleus

chain reaction

a reaction in which the material that starts the reaction is also one of the products, which causes another reaction to proceed

A(n) ________________ is a reaction in which the material that starts is a reactant in the reaction and is also one of the products, which causes another reaction to proceed.

chain reaction

Control rods placed between the fuel rods absorb some of the neutrons and control the rate of the ______________.

chain reaction

The steam from the nuclear reactor's heat exchanger is then conducted into the ___________, where it is cooled, condensed, and circulated back to the heat exchanger.

condenser

The minimum amount of fissionable material needed to sustain a chain reaction is called ___________.

critical mass

Massive amounts of _______ are released during nuclear fission and fusion.

energy

The tremendous amount of ______ released by nuclear fission is due to two reasons. First, binding energy is released when nucleons come apart. Second, a small part of the ______ of the original nuclide is converted to energy.

energy mass

After water in the heat exchanger absorbs heat from the nuclear reactor, the water turns to steam and passes to the electric ____________.

generator

The heat exchanger transfers heat from a nuclear reactor to the water in the __________________.

heat exchanger

The simplest example of fusion is the fusion of 4 hydrogen nuclei (protons) into one _________ nucleus. Under conditions of extreme temperature and pressure, they can be fused.

helium

Fusion releases tremendous amounts of energy, much more than is released by fission. Fusion produces a greater loss of mass than fission. Since more ________ is converted to energy, more energy is liberated.

mass

During ______________, a larger, heavier, unstable nucleus splits into two or more smaller, lighter, stable nuclei.

nuclear fission

An atomic bomb produces an uncontrolled chain reaction that releases energy in the form of heat and ____________.

radiation

Because of the dangers of __________, the nuclear reactor is housed in a containment structure consisting of steel-reinforced concrete and lead.

radiation

critical mass

the minimum amount of fissionable material needed to sustain a chain reaction