reactor

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

reactor

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

Reactor

 

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.

reactor

[rē′ak·tər]
(chemical engineering)
Device or process vessel in which chemical reactions (catalyzed or noncatalyzed) take place during a chemical conversion type of process.
(electricity)
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 ?
A stable self-sustaining chain reaction has started at the fourth nuclear reactor of the Takahama nuclear power plant in Japan, the plant's operator Kansai Electric Power Company (KEPCO) said.
By 2019, five more nuclear reactors are to re-start, including Shikoku Electric's 890MW No.
These special materials are totally absent in a nuclear reactor that wipes out even the chances of being explosive.
TechNavio's report, Global Nuclear Reactor Construction Market 2014-2018, has been prepared based on an in-depth market analysis with inputs from industry experts.
There have been safety concerns over the generation of power from nuclear reactors amid environmental safety concerns and the need to cut carbon emissions to control climate change.
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.
BKW Energie AG, based in Berne, Switzerland, announced it plans to challenge a court ruling that operating license of the company's Muehlebeg nuclear reactor should expire at the end of June 2013.
Nuclear reactors had been providing about 30 percent of the country's electricity needs which was expected to increase to at least 40 percent by 2017, prior to the Fukushima accident.
Japan's government approved bringing the country's first nuclear reactors back online since last year's earthquake and tsunami led to a nationwide shutdown, going against wider public opinion that is opposed to nuclear power after Fukushima.
This means that Switzerland's five nuclear reactors will not be replaced when they come up for renewal in 2034.
Yesterday the Office for Nuclear Regulation said: "Generic designs for two nuclear reactors proposed for construction in the UK have been granted interim design acceptance by the independent nuclear safety, security and environment regulators.

Full browser ?