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## Main Question or Discussion Point

I have to make a shielding calculation of some radioactive scrap metal in a cask, using Geant4 (hence Monte-Carlo).

I will be given a nuclide vector and I'll have to calculate the ambient dose equivalent rate outside of the cask.

The nuclide vector I will be given will be something like:

Co60 X Bq

Cs137 Y Bq

etc...

The problem is that I've been told that I must not only consider the activity of the expressly listed nuclides but also of any eventual daughter in equilibrium with the parent, even if not expressly listed.

The question is:

how do professionals usually deal with this problem ? How do they calculate the daughters' activities ? By hand ?

In principle I can try to calculate by hand all the equilibria related to each listed nuclide, but there are nuclides having many different decay branches, each with its own decay constant: it's going to be laborious.

I've been asked to prepare a budget of working hours for the simulation. I'm afraid that such a preliminary work only to calculate all the possible equilibria is going to deeply affect the budget.

Consider that just a nuclide like Co60 can decay through beta-minus to two possible excited states of Ni60, each in turn with its own gamma-decay-constant...

Thank you in advance.

I will be given a nuclide vector and I'll have to calculate the ambient dose equivalent rate outside of the cask.

The nuclide vector I will be given will be something like:

Co60 X Bq

Cs137 Y Bq

etc...

The problem is that I've been told that I must not only consider the activity of the expressly listed nuclides but also of any eventual daughter in equilibrium with the parent, even if not expressly listed.

The question is:

how do professionals usually deal with this problem ? How do they calculate the daughters' activities ? By hand ?

In principle I can try to calculate by hand all the equilibria related to each listed nuclide, but there are nuclides having many different decay branches, each with its own decay constant: it's going to be laborious.

I've been asked to prepare a budget of working hours for the simulation. I'm afraid that such a preliminary work only to calculate all the possible equilibria is going to deeply affect the budget.

Consider that just a nuclide like Co60 can decay through beta-minus to two possible excited states of Ni60, each in turn with its own gamma-decay-constant...

Thank you in advance.