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A subcritical reactor works by using neutrons from a source outside the reactor, instead of from within. This means that it can operate without being critical or nearly critical.
The neutrons are provided by bombarding a spallation target, which could be lead, Mercury, bismuth, or some other heavy element, with high energy protons that have been accelerated in a particle accelerator. When such a proton hits a lead atom, it can cause a cascade of high energy neutrons. These are passed into, or even generated within, the reactor itself.
In the reactor, the reaction is somewhat different from what goes on in a conventional nuclear reactor. Both have neutron capture and fission going on. But the subcritical reactor does not require a critical mass, and so the radioactive materials in it can all be exposed to neutrons continually without any need to remove them for refuelling as the lead medium and lead produced can be distilled out gradually while new fuel is added. The result is that the waste is almost entirely made up of radiologically inert materials.
Thorough computer modelling has been done, and reveals that the electrical power needed to drive a reactor of 650 mW electrical output is about 65 mW. The fuel can be thorium, uranium, or nuclear waste, and there is enough thorium to provide power for millennia, if things work as projected. Also, the reactor itself cannot melt down, and cannot be used to make bombs. But it may give us the ability to consume, and render inert, our nuclear waste.
No plant of this type has yet been built. There are a number of plants in planning, and a realistic hope that they will work.
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How do you create a sentence using the word dispersal?
The runaway reactor at Chernobyl went subcritical by prompt dispersal.
Is the nuclear reactor useful to made atom bombs?
Yes, the nuclear reactor can be useful when it comes to making nuclear weapons. Uranium can be lowered into the operating reactor and can be bathed in the neutron flux to become (through nuclear transformation) plutonium. Plutonium is ready to be shaped into the subcritical masses used in nuclear weapons.
What going to happen if the nuclear power plant melts down?
A meltdown is both good and bad:Good reactor design uses the meltdown to disassemble the fuel into a subcritical mass, causing the reactor to automatically shutdown.Bad reactor design can allow the fuel to enter places it should not go, possibly causing steam explosions, contamination outside the reactor containment, etc.
If the control rods in a nuclear reactor are removed would the condition be supercritical or subcritical?
If the control rods in a nuclear reactor were somehow to be instantly "jerked" out of the reactor, the reactor would go supercritical. If they were pulled at a normal rate and all of the control rods were pulled out, the reactor would start up and heat up and would end up running far too hot. Any one of several safety systems would shut the reactor down before this could happen. If the safety systems were disabled, the reactor would overheat and a meltdown may occur.
How does a phosphate reactor work?
MAGIC!!!!!!!!!
When do a nuclear reactor become critical or subcritical?
Critical is that point when the population of fission events is neither growing nor decreasing, and that it is sustained by its own means. In this state, on a large scale statistical basis, exactly one neutron produces one fission, which goes one to produce one neutron, which goes on to produce one fission, and so on and so forth. Subcritical is the state where that population is decreasing, and supercritical is where that population is increasing. Criticality is also related to power output, as the number of fission events is directly tied to energy or power output. When you ramp a nuclear reactor up in power, you go slightly supercritical while you increase the population, and therefore the energy output, but once you achieve your target power, you let your moderator step in and modulate the power in a self-modulating cycle. Similarly, as you trim power down, you go slightly subcritical while you decrease the population, and then you let the moderator kick back in, that is, unless you lose control and you initiate a trip/scram, taking the reactor to shutdown, which is way-way-subcritical.
How does a reactor work on thermal power plant?
Reactor is used for distilling water in thermal power plants.
How does SSP reactor work?
Please define meaning of SSP
How does the arc reactor work from the movie iron man?
It lights up
Of the reaction in a nuclear reactor must be controlled so that it may produce heat rather than a violent explosion?
A nuclear reactor cannot produce a nuclear explosion under any conditions. They can however produce steam explosions and hydrogen gas explosions.One test reactor in Idaho (BORAX-I) was actually deliberately destroyed to verify the safety of a runaway reactor:four of its five control rods were almost removedthe fifth control rod was ejected with a spring, making the reactor severely supercriticalthe resulting steam explosion blew the reactor completely apart (instantly returning it to a subcritical state, preventing any possibility of a nuclear explosion)severe contamination existed beyond a distance of half a mile (had the reactor been enclosed in a containment building most if not all of this would have been prevented)
Can a nuclear power plant turn into a atomic bomb?
No, a reactor is operated at critical and a bomb at supercritical. Also reactors include safety shutdown systems that quickly make them subcritical stopping the reaction.However reactors can have steam explosions and hydrogen/oxygen explosions. These are physical and chemical explosions respectively, not nuclear.
How many people work in the nuclear reactors?
No one work inside a nuclear reactor, it is operated from outside.
