what is a nuclear reactor?

Question

no idea

Answer 1

Here's a bit of information - for further information (including some of the scientific terms used) check out the source information which links to information on fission, chain reactions, neutrons and more.

What Is A Nuclear Reactor?

All nuclear reactors are devices designed to maintain a chain reaction producing a steady flow of neutrons generated by the fission of heavy nuclei. They are, however, differentiated either by their purpose or by their design features. In terms of purpose, they are either research reactors or power reactors.

Research reactors are operated at universities and research centres in many countries, including some where no nuclear power reactors are operated. These reactors generate neutrons for multiple purposes, including producing radiopharmaceuticals for medical diagnosis and therapy, testing materials and conducting basic research.

Power reactors are usually found in nuclear power plants. Dedicated to generating heat mainly for electricity production, they are operated in more than 30 countries (see Nuclear Power Reactors). Their lesser uses are drinking water or district water production. In the form of smaller units, they also power ships.

Answer 2

A nuclear reactor is a 'vessel' in which nuclear reactions are carried out. When I say 'vessel' it does not mean that it is comparable to any laboratory vessels we use. This vessel, sometimes, may be the size of a multi-storey building. Nuclear reactions, primarily fission reactions (breaking of big nucleus to smaller ones), is accompanied by the release of heat and harmful radiations. This is effectively converted to useful energy in a nuclear reactor. There are a whole lot of useful applications of nuclear power. When this goes uncontrolled, this is called an atom bomb.

Answer 3

Here's a bit of information - for further information (including some of the scientific terms used) check out the source information which links to information on fission, chain reactions, neutrons and more.

What Is A Nuclear Reactor?

All nuclear reactors are devices designed to maintain a chain reaction producing a steady flow of neutrons generated by the fission of heavy nuclei. They are, however, differentiated either by their purpose or by their design features. In terms of purpose, they are either research reactors or power reactors.

Research reactors are operated at universities and research centres in many countries, including some where no nuclear power reactors are operated. These reactors generate neutrons for multiple purposes, including producing radiopharmaceuticals for medical diagnosis and therapy, testing materials and conducting basic research.

Power reactors are usually found in nuclear power plants. Dedicated to generating heat mainly for electricity production, they are operated in more than 30 countries (see Nuclear Power Reactors). Their lesser uses are drinking water or district water production. In the form of smaller units, they also power ships

Answer 4

The nuclear reactor (or atomic reactor) is a kind of furnace for carrying out the controlled fission of a radioactive material like uranium-235 for producing atomic power.

Answer 5

Nuclear Reactor is a place where they split the atoms of Uranium235 to produce elecrical energy.

Answer 6

The nuclear reaction interior the reactor center generates potential in the variety of warmth. This potential is then used to advance the temeprature of a circulating medium (many times uncomplicated water). The circulating medium is then pumped via a turbine that's immediately linked to an electric device (generator). The rotation of the turbine via the compelled steam motives the electrical powered device to teach as properly, thereby producing electrical energy. The medium (steam) is then cooled after it exits the turbine, to permit it to recirculate and %. up extra warmth from the reactor, for this reason coming up a non-provide up closed loop device.

Answer 7

Nuclear reactor at the core of the Earth! – A solution to the riddles of relative abundances of helium isotopes and geomagnetic field variability.

Answer 8

A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate (as opposed to a nuclear bomb, in which the chain reaction occurs in a fraction of a second and is completely uncontrolled).

Nuclear reactors are used for many purposes. The most significant current use is for the generation of electrical power (see nuclear power). Research reactors are used for radioisotope production and for beamline experiments with free neutrons. Historically, the first use of nuclear reactors was the production of weapons grade plutonium for nuclear weapons. Another military use is submarine / ship propulsion (Though this involves a much smaller nuclear reactor than one used in a nuclear power plant).

Currently all commercial nuclear reactors are based on nuclear fission, and are considered by some to be a safe and pollution-free method of generating electricity. Conversely, some consider nuclear reactors problematic for their potential safety and health risks. Fusion power is an experimental technology based on nuclear fusion instead of fission. There are other devices in which nuclear reactions occur in a controlled fashion, including radioisotope thermoelectric generators and atomic batteries, which generate heat and power by exploiting passive radioactive decay, as well as Farnsworth-Hirsch fusors, in which controlled nuclear fusion is used to produce neutron radiation.

A number of reactor technologies have been developed. Fission reactors can be divided roughly into two classes, depending on the energy of the neutrons that are used to sustain the fission chain reaction.

- Thermal (slow) reactors use slow or thermal neutrons. These are characterized by having moderating materials which are intended to slow the neutrons until they approach the average kinetic energy of the surrounding particles, that is, until they are thermalized. Thermal neutrons have a far higher probability of fissioning U-235, and a lower probability of capture by U-238 than the faster neutrons that result from fission do. As well as the moderator, thermal reactors have fuel (fissionable material), containments, pressure vessels, shielding, and instrumentation to monitor and control the reactor's systems. Most power reactors are of this type, and the first plutonium production reactors were thermal reactors using graphite as the moderator. Some thermal power reactors are more thermalised than others; Graphite (ex. Russian RBMK reactors) and heavy water moderated plants (e.g. Canadian CANDU reactors) tend to be more thoroughly thermalised than PWRs and BWRs, which use light water (normal water) as the moderator (due to the extra thermalization, these types can use natural uranium/unenriched fuel).

- Fast reactors use fast neutrons to sustain the fission chain reaction, and are characterized by the lack of moderating material. They require highly enriched fuel (sometimes weapons-grade), or plutonium in order to reduce the amount of U-238 that would otherwise capture fast neutrons. Some are capable of producing more fuel than they consume, usually by converting U-238 to Pu-239. Some early power stations were fast reactors, as are some Russian naval propulsion units, and construction of prototypes is continuing (see fast breeder), but overall the class has not achieved the success of thermal reactors in any application. An example of this type of reactor is the Fast Breeder Reactor (FBR).

Thermal power reactors can again be divided into three types, depending on whether they use pressurised fuel channels, a large pressure vessel, or gas cooling.

- Pressure vessels holding steam heated by the reactor are used by most commercial and naval reactors. The pressure vessel serves to balance out pressure transients in the primary loops which occur with reactor power changes. The pressure vessel also serves a small role as a primary coolant make-up source. The pressure vessel is almost always lined up to the reactor and is only isolated from the reactor for special maintenance or testing.

- Pressurised channels are used by the RBMK and CANDU reactors. Channel-type reactors can be refuelled under load, which has advantages discussed under CANDU reactor.

- Gas-cooled reactors are cooled by a circulating inert gas, usually helium, but nitrogen and carbon dioxide have also been used. Utilisation of the heat varies, depending on the reactor. Some reactors run hot enough that the gas can directly power a gas turbine. Older designs usually run the gas through a heat exchanger to make steam for a steam turbine. The pebble bed reactor uses a gas-cooled design.

Since water serves as a moderator, it cannot be used as a coolant in a fast reactor. Most designs for fast power reactors have been cooled by liquid metal, usually molten sodium. They have also been of two types, called pool and loop reactors.

Current families of reactors

- Pool-type reactor
- Pressurized water reactor (PWR)
- Boiling water reactor (BWR)
- Fast breeder reactor (FBR)
- Pressurized Heavy Water Reactor (PHWR) or CANDU
- United States Naval reactor

Obsolete types still in service

- Magnox reactor
- Advanced gas-cooled Reactor (AGR)
- Light water cooled graphite moderated reactor (RBMK)

Other types of reactors

- Aqueous Homogeneous Reactor
- Liquid Fluoride Reactor

Advanced reactors

More than a dozen advanced reactor designs are in various stages of development.[10]Some are evolutionary from the PWR, BWR and PHWR designs above, some are more radical departures. The former include the Advanced Boiling Water Reactor (ABWR), two of which are now operating with others are under construction, and the planned passively safe ESBWR and AP1000 units (see Nuclear Power 2010 Program). The best-known radical new design is the Pebble Bed Modular Reactor (PBMR), a High Temperature Gas Cooled Reactor (HTGCR). The Clean And Environmentally Safe Advanced Reactor (CAESAR) is a nuclear reactor concept that uses steam as a moderator - this design is still in development. Possible designs of subcritical reactors exist on the drawing board, notably the energy amplifier, awaiting political support and funding. Some, such as the Integral Fast Reactor (IFR), have been cancelled due to a political climate unfavorable to nuclear power.

Generation IV reactors

Even more-advanced reactors are also on the drawing boards. These are the Generation IV reactors, which are divided into six overall design classes.

- Gas cooled fast reactor
- Lead cooled fast reactor
- Molten salt reactor
- Sodium-cooled fast reactor
- Supercritical water reactor
- Very high temperature reactor
- Fission fragment reactor

Answer 9

in which neuclear reaction will be going on under controlled condition