chain reactions (1 Viewer)

[angelduck]

OK, how much do we actually need to know on the requirements for cointrolled and uncontrolled reactions??

I have very little, basically on the theory behind a controlled reactor.

Plz help! Do i need more? and if possible, what?

 

[acmilan]

You need to know what differs between the two. For example in a controlled reaction there needs to be something (ie. control rods) to absorb excess neutrons. The reaction needs to be monitored to ensure that the reaction is controlled. In uncontrolled it does not have to be controlled through control rods the reaction rapidly increases.

 

[Tommy_Lamp]

What i mention is the basic process: U-235 + 1/0 n --> 92/36 Kr + 141/56 Ba + 3 1/0n + energy. then say that in a controlled nuclear chain reaction cadmium control rods are used to absorb 2 of the 3 neutrons that are released, thereby allowing only one neutron to further react. In an uncontrolled nuclear chain reaction, none of the neutrons are absorbed hence all 3 react.
i also add diagrams for both. they are in your excel book

 

[Xayma]

What i mention is the basic process: U-235 + 1/0 n --> 92/36 Kr + 141/56 Ba + 3 1/0n + energy. then say that in a controlled nuclear chain reaction cadmium control rods are used to absorb 2 of the 3 neutrons that are released, thereby allowing only one neutron to further react. In an uncontrolled nuclear chain reaction, none of the neutrons are absorbed hence all 3 react.
i also add diagrams for both. they are in your excel book

Be careful saying all 3 react. Some will be lost thats what a crictical mass is. The small relative surface area minimises lost neutrons. Also some will be absorbed but don't cause fission because it isn't competley U-235.

 

[Tommy_Lamp]

so what would be better to say instead of react?

 

[Xayma]

Nearly all neutrons release cause another nuclei to undergo fission.

 

[Tommy_Lamp]

ah ok, danke