As the name says, Control Rod is a control device that is use to provide precise and adjustable control of reactivity in the reactor core.
When reactivity is controlled, the power output is also controlled.
Basically, control rods function by absorbing neutrons from generating another nuclear reaction.
Nuclear reaction or fission generates heat.
If the heat generated is not controlled, overheating will occur.
This will make the the reactor components such as the fuel rods melt.
Control rods also function as a safety device.
In the event of emergengy, control rods can be release completely to shut down the reactor.
Control rods materials:-
- Silver, Ag
- Indium, In
- Cadmium, Cd
- Boron, B
- Hafnium, Hf
In a more proper way of writing, the purpose of control rods includes:-
- Coarse control and/or to remove reactivity in relatively large amounts - Shim rods.
- Fine control and to maintain desired power or temperature - Regulating rods.
- Provides fast shut down in the event of unsafe and emergency condition - Safety rods.
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Image from Google -Click for larger view- |
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| Image from Google -Click for larger view- |
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| Image from Google -Click for larger view- |
Again, we can see that Nuclear Reactor is full of safety features!
:)
4 comments:
as i see in picture... where does the source for material that used to produce steam comes from...???
sivabalan s/o sanafhei raja
me083646
HI,
This is info about Additional means of reactivity regulation.
Usually there are also other means of controlling reactivity: In the PWR design a soluble neutron absorber (boric acid) is added to the reactor coolant allowing the complete extraction of the control rods during stationary power operation ensuring an even power and flux distribution over the entire core. This chemical shim, along with the use of burnable neutron poisons within the fuel pellets, is used to assist regulation of the long term reactivity of the core,while the control rods are used for rapid changes to the reactor power (e.g. shutdown and start up). Operators of BWRs use the coolant flow through the core to control reactivity by varying the speed of the reactor recirculation pumps (an increase in coolant flow through the core improves the removal of steam bubbles, thus increasing the density of the coolant/moderator with the result of increasing power).
Amreet Raj Singh
ME083528
(amreet90@hotmail.com)
Hi,you have mention that control rod works a safety device, Chernobyl disaster is famous for malfunction of NPP. Does this NPP or older version of NPP have this control rod in them?
vaageesan ganeesan
macha15_swimfaster@yahoo.com
As you said Control rods also function as a safety device.
In the event of emergengy, control rods can be release completely to shut down the reactor.But will this act will be the first choice to turn off the reactor.And let say in a situation where the nuclear is operating it its optimum level.How long does it take to shut down by using this control rods.vimalan a/l genasan.vimalan_12@yahoo.com
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