Fusion Activation: Analysis & Calculation | Why Needed?

[Amjad78]

Hello Everybody i hope you all will be fine, can some one tell me about the activation analysis of fusion? why Activation is needed in Fusion reactor? what methodology can be used for this calculation?

 

[Simon Bridge]

Activation is needed for a fusion reaction for the same reason you need activation to light a fire ... but the specific meaning can depend on the context. For instance, in the headline "Germany activates first fusion reactor" it just means they switched it on.

 

[Amjad78]

Activation is needed for a fusion reaction for the same reason you need activation to light a fire ... but the specific meaning can depend on the context. For instance, in the headline "Germany activates first fusion reactor" it just means they switched it on.

It is assumed that there is no high level waste produced in fusion but on calculating some isotopes are very long lived and very highly radioactive. And also they says that in maintenance worker are allowed to access after 12 days of shutdown but is this acceptable i think the activity level will be very high.

 

[Drakkith]

It is assumed that there is no high level waste produced in fusion but on calculating some isotopes are very long lived and very highly radioactive.

A substance is either very long lived or highly radioactive, not both. A highly radioactive substance decays at a much quicker rate than a less radioactive substance (and the more decays per second the more radioactive it is), so it has a shorter lifetime.

And also they says that in maintenance worker are allowed to access after 12 days of shutdown but is this acceptable i think the activity level will be very high.

Do you have a source for all of this? I'd be interested in reading it.

 

[Simon Bridge]

Oh I see: by "activation" you mean how radioactive something is?
That is usually called "strength" or "activity" or "radiation level"...
To find out how radioactive a reaction product is likely to be, you look it up in a book.
To find out how long to wait before maintenance folk can enter an area and what protection they need, you look it up in a book of industrial regulations.
What is your education level?

It would be nice to know where you are getting this from too.

 

[Amjad78]

A substance is either very long lived or highly radioactive, not both. A highly radioactive substance decays at a much quicker rate than a less radioactive substance (and the more decays per second the more radioactive it is), so it has a shorter lifetime.
Do you have a source for all of this? I'd be interested in reading it.

I am also working on this and i have some data what kind of data you need i will send you, no problem

 

[Drakkith]

Just a link to a website or paper will do if you have it.

 

[Toast]

Hi there

I have carried out a little activation analysis of fusion reactors. It is a fascinating subject

To minimize activation in DT fusion devices advanced lo activation materials have been developed.

Eurofer is an example of a modified steel that doesn't get activated as much as regular steel

One option for simulating activation would be to use codes like MCNP (to obtain neutron spectra) and FISPACT (to track particle transmutations).

The results can then be compared with experimental results in a benchmark

Two nice and clear animations are available from CCFE

This animation shows the activation of Eurofer
http://www.ccfe.ac.uk/assets/Documents/easy/Eurofer_chartandline_logo.mp4

This animation shows how it decays shortly afterwards
http://www.ccfe.ac.uk/assets/Documents/easy/Eurofer_chartandline_heat_logo.mp4

If the correct materials are used then fusion will not produce any long lived activation products.