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Because some of the fission products are neutron poisonsthat as they build up reduce the reactivity. Without the excess reactivity available to overcome this the reactor would shut itself down until the neutron poisons decayed away. This effect was observed in the first production reactor at Hanford (B reactor) when it was first started.
Excess reactivity is designed into nuclear reactors to allow for control over the reactor's power level and to ensure safety margins are maintained. It provides flexibility to adjust power output and respond to changes in operating conditions, such as changes in fuel burnup or reactor configuration. Having excess reactivity also enables operators to compensate for uncertainties in reactor behavior.
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What chemical reactions are involved in a nuclear reactor?
In a nuclear reactor, the main chemical reactions involve nuclear fission, whereby heavy atomic nuclei such as uranium-235 split into smaller nuclei, releasing energy and neutrons. These neutrons go on to induce further fission reactions in a chain reaction, creating a sustained release of energy. Control rods are used to regulate the reaction by absorbing excess neutrons to maintain a steady power output.
How many fuel channels does an advanced gas-cooled reactor have?
I don't believe that the design is fixed at this time. General Atomics and others have been working on designs and one has been built in South Africa, but the companies are still working out the final design. A link is provided to an interesting read on the latest evelopments. The advanced gas-cooled reactors, at least the ones I know, have been built in the UK but not elsewhere. The last ones built were at Heysham Stage 2 and Torness, in Scotland. As far as I can remember the number of channels was 332. I think the first answer may have been on the pebble bed reactor, which is gas cooled and advanced, but not the same as the AGR in UK.
What Nuclear material is used in nuclear power plant?
The reactor is usually initially fueled with uranium (for water moderated reactors this is enriched to 3% uranium-235, but other designs may be enriched more or less than that). A few reactors (e.g. reactors in France) are initially fueled with plutonium or a mixture of both uranium and plutonium.After a reactor has operated for a period of time significant levels of transuranic elements have built up in the reactor core, these will also fission and the reactor uses them also as fuel (but unless it is a fast breeder reactor it neither produces nor burns these transuranic fuels very efficiently.Note: a fast breeder reactor contains no moderator to slow neutrons and therefor if fueled with uranium usually requires it to be enriched to 93.5% uranium-235, commonly referred to as weapons grade uranium). The advantage of a fast breeder is that it efficiently converts the normally unusable uranium-238 to plutonium and other transuranics. The plutonium it produces would have far too much plutonium-240 and plutonium-241 in it (due to long fuel burn cycles) for use in weapons and could be used to fuel nuclear reactors of other types. It is also able to efficiently burn all the transuranics it produces, meaning the waste it produces would contain little more than the fission products which all have short halflives; therefor this waste would only have to be stored a few hundred years (not the tens of thousands of years that the wastes of current reactors must be stored, because they still contain unburned plutonium and other transuranics).
What is ITER?
Wikipedia, the free encyclopedia says, "In computer science, an iterator is an object which allows a programmer to traverse through all the elements of a collection, regardless of its specific implementation. An iterator is sometimes called a cursor, especially within the context of a database."Source: http://en.wikipedia.org/wiki/Iterator
Where was the cobalt bomb made?
The cobalt bomb is a theoretical type of nuclear weapon designed to produce massive amounts of radioactive cobalt-60. It has not been built or tested because of the extreme consequences it would have on the environment.
When and where was last nuclear reactor built?
The last nuclear reactor has not been built yet.
When was the first nuclear reactor built?
The first demonstration nuclear reactor was built in USA by Enrico Fermi in Chicago Stadium. Fermi was an Italian Physicist, best known for his work on Chicago Pile-1 (the first nuclear reactor). on 26 June 1954, in the town of Obninsk, near Moscow in the former USSR, the first nuclear power plant was connected to an electricity grid to provide power to residences and businesses. Nuclear energy had crossed the divide from military uses to civilian applications.
Where was the first South African nuclear reactor built?
Koeburg
What were some of the uses for the first nuclear reactor?
The very first nuclear reactor was Chicago Pile 1. It was built for research and scientific use. The first nuclear reactor outside of a university was built (at Hanford, Washington) primarily to yield plutonium for the atomic bomb destined for Nagasaki, Japan. Nuclear reactors were built primarily for electrical generation beginning in about 1951.
In 1950 where was the first nuclear reactor?
The first nuclear reactor was in former Soviet Union that operated in year 1954 at obninisk.
Who was the inventor of first nuclear plant?
Leo Szilard invented the nuclear reactor in 1933, but did not build it.Enrico Fermi built first nuclear reactor, CP-1 in 1942.Walter Zinn built the first nuclear power plant, EBR-1 in 1951.
What are the release dates for TEDTalks - 2006 Taylor Wilson Yup I Built a Nuclear Fusion Reactor?
TEDTalks - 2006 Taylor Wilson Yup I Built a Nuclear Fusion Reactor was released on: USA: March 2012
Could a reactor be fueled with americium?
The Russians are working on the problem of creating a nuclear reactor fuel out of americium, but they're still working the problem. In addition, they haven't built a reactor that uses americium as a nuclear fuel yet, either.
Does nuclear reactors contain uranium-235?
It really depends on the nuclear reactor, but many are built to work specifically with that isotope.
Who built the first nuclear fission reactor?
Enrico Fermi at the U of Chicago squash court
Under what NFL team's stadium was a nuclear reactor built?
The Chicago Bears, Soldier Field
Who first invented nuclear reactors?
The nuclear reactor was invented in 1933 by Leo Szilard, in London, but he did not try to build one. The first functioning nuclear reactor, CP-1, was designed and built in 1942 by Enrico Fermi, in Chicago, IL.
