Nuclear Fission and Fusion

Chain Reaction (Nuclear)

A self-sustaining series of nuclear fissions in which neutrons released from one fission trigger additional fissions.

Waste Products (Fusion vs. Fission)

Fusion produces helium, which is non-radioactive, while fission produces radioactive waste materials.

Daughter Isotopes

The smaller nuclei that are produced as a result of a nuclear fission event.

Element Formation in Stars

The creation of elements up to iron through nuclear fusion reactions within stars.

Lowering Control Rods

Action that decreases the rate of nuclear reactions and steam production by increasing neutron absorption.

Artificial Nuclear Process (Fission)

A nuclear reaction that is human-induced and does not occur naturally.

Control Rods

Components in a nuclear reactor used to absorb neutrons and regulate the rate of the nuclear chain reaction, often made of cadmium.

Heavy Isotopes

Isotopes with a large number of nucleons (protons and neutrons) in their nuclei.

Long-Term Storage of Nuclear Waste

The problematic aspect of finding safe, permanent disposal methods for radioactive waste.

Nuclear Reactor Energy Production

A process where heat from fission boils water, creating steam that turns a turbine to generate electricity.

Nuclear Waste

Radioactive materials, such as control rods, that require special disposal methods due to their long-term radioactivity.

Exponential Growth in Fission

The rapid increase in the number of nuclear reactions due to each fission event producing multiple neutrons that trigger further fissions.

Supernova Explosions

The event where elements heavier than iron are formed through nuclear reactions.

Neutron

A subatomic particle with no electric charge and a mass approximately equal to that of a proton.

Challenges of Earth-Based Fusion

Maintaining extreme temperatures and containing the reaction without stellar gravity are significant obstacles.

Raising Control Rods

Action that increases the rate of nuclear reactions and steam production by reducing neutron absorption.

Underground Facilities

Current method of storing nuclear waste, though long-term solutions are still needed.

Energy Source of the Sun

The process of hydrogen nuclei fusing to form helium, releasing vast amounts of energy.

Gamma Radiation

High-energy electromagnetic radiation emitted during nuclear reactions.

Hydrogen Bomb

A weapon that uses fusion reactions to release a tremendous amount of energy, significantly more powerful than an atomic bomb.

Nucleus

The dense region at the center of an atom, consisting of protons and neutrons.

Radioactive Control Rods

Used reactor components that have absorbed neutrons and become radioactive waste.

Stellar Gravity

The immense gravitational force within stars that helps contain and sustain nuclear fusion reactions.

Neutron Bombardment

The process of striking a nucleus with neutrons to induce instability and initiate a nuclear reaction.

Radiation Shielding

Materials like concrete and lead used to block or reduce the intensity of harmful emissions.

Artificial Fission

The human-induced splitting of heavy nuclei, distinct from any spontaneous decay process.

Induced Nuclear Reaction

A nuclear reaction that does not occur naturally; it is initiated by external factors, such as neutron bombardment.

Contamination Prevention in Reactors

Use of separate water systems and heat exchangers to keep radioactive materials isolated.

Nuclear Power Plant

A facility that utilizes controlled nuclear fission to generate electricity.

Heat Exchangers

Devices used in nuclear reactors to transfer heat from the reactor core to a separate water system without radioactive contamination.

Confinement Shell

A structure, typically made of concrete with a lead liner, designed to contain radiation within a nuclear reactor.

Isotopes

Variants of a chemical element which differ in neutron number, and consequently in nucleon number.

Energy Output (Fusion vs. Fission)

Fusion reactions release approximately 4-5 times more energy compared to fission reactions.

Nuclear Chain Reaction Control

Regulation of reaction rates in reactors through the use of materials that absorb neutrons.

Fuel for Nuclear Fusion

Hydrogen isotopes, such as deuterium and tritium, are commonly used.

Waste Disposal Challenges

The difficulties associated with safely storing radioactive materials for extended periods.

Radioactive Materials

Substances that emit ionizing radiation due to the decay of their atomic nuclei.

Mass Conservation in Fission

The principle stating that the total mass before and after a nuclear fission reaction remains the same when accounting for all products and energy released.

Helium

A non-radioactive gas produced as a byproduct of nuclear fusion reactions.

Nuclear Fusion

A process where smaller nuclei combine to form larger nuclei, releasing a significant amount of energy; it occurs naturally in stars.

Tritium

An isotope of hydrogen with one proton and two neutrons in its nucleus.

Birth of Stars

The event marked by the ignition of nuclear fusion reactions in the core of a protostar.

Conditions for Nuclear Fusion

Extremely high temperatures (e.g., 40 million °C) and high pressure/gravity are needed to overcome electrostatic repulsion.

Fusion Products

The resultant nuclei from a fusion reaction.

Often these are stable (non-radioactive)

isotopes of heavier elements.

Temperature Requirements (Fusion vs.

Fission)

Fusion requires extremely high temperatures (e.g., 40 million °C), while fission requires moderate temperatures.

Turbine

A rotary engine that extracts energy from a fluid flow (steam) and converts it into useful work.

Nuclear Fission

Process where a heavy nucleus splits into smaller fragments, releasing energy and additional neutrons, often initiated by neutron bombardment.

Cadmium

A metallic element commonly used in control rods due to its ability to absorb neutrons.

Natural Nuclear Process

A nuclear reaction that occurs spontaneously in nature, such as fusion in stars.

Deuterium

An isotope of hydrogen with one proton and one neutron in its nucleus.

Fusion Ignition

The point at which nuclear fusion reactions begin and become self-sustaining in a star.