(redirected from Nuclear reactors)
Also found in: Dictionary, Thesaurus, Medical.
Related to Nuclear reactors: nuclear fusion


1. Chem a substance, such as a reagent, that undergoes a reaction
2. short for nuclear reactor
3. a vessel, esp one in industrial use, in which a chemical reaction takes place
4. a coil of low resistance and high inductance that introduces reactance into a circuit
5. Med a person sensitive to a particular drug or agent



an induction coil hooked into an electrical circuit to eliminate or suppress the alternating component of current in the circuit or to separate or restrict signals of various frequencies. Reactors are hooked into a circuit in series with a load (see Figure 1): the electrical reactance Z(ω) depends on the frequency of the current:

Z(ω) = ωL

where ω = 2 πf (f is the frequency in hertz) and L is the inductance of the reactor, in henrys. For example, a reactor with high electrical resistance to the alternating component of the current is used as a filter element in current rectifiers.

Figure 1. Diagram of connection of a reactor to an electrical circuit: (R) reactor, (R1) load, (U) supply voltage

Reactors are usually made with a core of electrical steel, permalloy, or special materials with high magnetic permeability (such as a ferrite core) to increase inductance, that is, to increase their reactance to alternating current.


(chemical engineering)
Device or process vessel in which chemical reactions (catalyzed or noncatalyzed) take place during a chemical conversion type of process.
A device that introduces either inductive or capacitive reactance into a circuit, such as a coil or capacitor. Also known as electric reactor.
(nuclear physics)

Reactor (electricity)

A device for introducing an inductive reactance into a circuit. Inductive reactance x is a function of the product of frequency f and inductance L; thus, x = 2πfL. For this reason, a reactor is also called an inductor. Since a voltage drop across a reactor increases with frequency of applied currents, a reactor is sometimes called a choke. All three terms describe a coil of insulated wire. See Inductor

According to their construction, reactors can be divided into those that employ iron cores and those where no magnetic material is used within the windings. The first type consists of a coil encircling a circuit of iron which usually contains an air gap or a series of air gaps. The air gaps are used to attenuate the effects of saturation of the iron core. The second type, called an air-core reactor, is a simple circular coil, wound around a cylinder constructed of nonmagnetic material for greater mechanical strength. This strength is necessary for the coil to withstand the electromagnetic forces acting on each conductor. These forces become very large with heavy current flow, and their direction tends to compress the coil into less space: radial forces tend to elongate internal conductors in the coil and to compress the external ones while the axial forces press the end sections toward the center of the coil.

Both iron-core and air-core reactors may be of the air-cooled dry type or immersed in oil or a similar cooling fluid. Both types of reactors are normally wound with stranded wire in order to reduce losses due to eddy currents and skin effect. In addition, it is important to avoid formation of short-circuited metal loops when building supporting structures for air-core reactors since these reactors usually produce large magnetic fields external to the coil. If these fields penetrate through closed-loop metal structures, induced currents will flow, causing both losses and heating of the structures. Which of these two reactor types should be used depends on the particular application. See Eddy current

References in periodicals archive ?
We are developing our own type of nuclear reactors, Smart, small-sizes plants which are safer than the original designs.
In addition, fresh business to supply nuclear reactors in Kazakhstan was "under negotiation", he said.
Also in May, Jordan will select the strategic partner of the project, Toukan said, adding that the final agreement to build the nuclear reactor will be signed in the second half of 2013.
A bill was enacted earlier this year to require all existing nuclear reactors from next July to fit safety standards based on the latest knowledge before being allowed to restart operation.
Despite having suffered the catastrophic consequences of nuclear weapons in wartime, Japan began using nuclear reactors to meet its growing energy needs to avoid depending on fossil fuel imports since the 1970s.
THE two nuclear reactor designs proposed for Wylfa B have won interim approval from the regulator.
If our Government and others seriously wish to avoid nuclear weapons proliferation, (and climate change), they would devote 1000% more effort into perfecting thorium nuclear reactors to make this the preferred choice for all future nuclear reactors.
World statistics show there are around 440 nuclear reactors now which provide about 16 per cent of global electricity needs.
NPCIL is expanding its capacity at the nuclear power plant by adding two nuclear reactors of 700 MW each.
The likely cost of electricity for a new generation of nuclear reactors would be 12 to 20 cents per kilowatt hour, considerably more expensive than the average cost of increased use of energy efficiency and renewable energies at six cents per kWh, according to a study by Mark Cooper, a senior fellow for economic analysis at the Institute of Energy and the Environment at Vermont Law School, South Royalton.
Nuclear reactors in the Southeast might be forced to temporarily shut down later this year if the drought continues to dry out rivers and lakes that supply power plants with the tremendous amounts of water they need to operate.

Full browser ?