Glossary
Defined terms
Jump from a letter or a domain, scan a card, then open the full definition. Search from the header to filter quickly.
A
B
B
Becquerel
SI unit of activity.
B
Binary cycle
Geothermal plant using a secondary working fluid.
B
Binding energy
Energy that holds a nucleus together.
B
Biogas
Methane-rich gas from anaerobic digestion.
B
Biomass
Organic matter used as fuel.
B
Blanket
Plasma-facing modules that capture neutrons and heat.
B
Boiling Water Reactor
Light-water reactor that boils in the core.
B
Breakeven
When fusion power matches heating power.
B
Bremsstrahlung
Radiation from decelerating charged particles.
C
C
CANDU
Canadian deuterium–uranium reactor.
C
Capacity factor
Actual energy produced divided by maximum possible.
C
Central solenoid
Transformer coil on a tokamak axis.
C
Cladding
Metal tube around nuclear fuel pellets.
C
Cogeneration
Combined heat and power.
C
Containment
Structure that confines radioactive material.
C
Control rod
Neutron-absorbing rod for reactor control.
C
Coolant
Fluid that removes heat from a reactor or plant.
C
Critical mass
Amount of fissile material that can sustain a chain reaction.
C
Cross-section
Probability measure for a nuclear reaction.
C
Cryostat
Vacuum vessel that thermally insulates cold magnets.
D
E
F
F
Fast neutron
Neutron that has not been slowed to thermal energies.
F
First wall
Plasma-facing surface of a fusion vessel.
F
Fission
Splitting of a heavy nucleus.
F
Francis turbine
Medium-head reaction water turbine.
F
Fuel assembly
Bundle of fuel rods.
F
Fuel cell
Electrochemical converter of fuel to electricity.
F
Fuel pellet
Ceramic cylinder of uranium dioxide.
F
Fusion
Joining of light nuclei.
F
Fusion gain Q
Ratio of fusion power to heating power.
G
H
H
Half-life
Time for half of a radionuclide to decay.
H
Heavy water
Water with deuterium instead of ordinary hydrogen.
H
Helias
Modular stellarator configuration.
H
Heliostat
Sun-tracking mirror.
H
Hohlraum
Cavity that converts laser light to X-rays.
H
Hormesis
Hypothesis that low doses may be beneficial.
H
HTGR
High-temperature gas-cooled reactor.
H
HVDC
High-voltage direct current transmission.
H
Hydrogen
Lightest element; energy carrier when manufactured.
I
I
IAEA
International Atomic Energy Agency.
I
Ignition
Self-heating fusion plasma.
I
Inertial confinement
Compressing fusion fuel faster than it can fly apart.
I
INES
International nuclear event scale.
I
Inherent safety
Safety that follows from physics, not active systems.
I
Ion cyclotron heating
RF heating at the ion cyclotron frequency.
I
Ionising radiation
Radiation that can ionize atoms.
I
Island divertor
Stellarator exhaust using magnetic islands.
I
Isotope
Atoms of an element with different neutron numbers.
I
ITER
International tokamak under construction in France.
J
K
L
M
N
P
P
Pelton turbine
High-head impulse water turbine.
P
Penstock
Pipe that carries water to a turbine.
P
Photovoltaic cell
Semiconductor device that converts light to electricity.
P
Photovoltaic effect
Generation of voltage from light in a junction.
P
Plasma
Ionized gas of charged particles.
P
Plutonium
Human-made actinide used in some fuels.
P
Poloidal field
Magnetic field the short way around a torus.
P
Pressure vessel
Steel vessel that holds a light-water reactor core.
P
Pressurized Water Reactor
Light-water reactor with a secondary steam circuit.
P
Proton
Positively charged nucleon.
P
Pumped storage
Hydroelectric energy storage using two reservoirs.
R
S
S
Scram
Rapid emergency shutdown of a reactor.
S
Sievert
SI unit of equivalent dose.
S
Smart grid
Power system with sensing, communication, and control.
S
SMR
Small modular reactor.
S
Solar collector
Device that captures sunlight as heat.
S
Spent fuel
Fuel removed from a reactor after irradiation.
S
Steam generator
Heat exchanger that makes steam in a PWR.
S
Stellarator
Magnetic fusion device with 3D external coils.
S
Superconductor
Material with zero DC resistance below a critical temperature.
T
T
Tesla
SI unit of magnetic flux density.
T
Thermal efficiency
Work output divided by heat input.
T
Thermal neutron
Neutron in thermal equilibrium with the moderator.
T
Tokamak
Toroidal magnetic fusion device using plasma current.
T
Toroidal field
Magnetic field the long way around a torus.
T
Tritium
Radioactive hydrogen isotope with two neutrons.
T
Tritium breeding
Making tritium from lithium in a fusion blanket.
T
Turbine
Rotary engine extracting energy from a fluid.