Depletion chain advice for VTB Gas-Cooled Microreactor

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Hello all!

I’m putting together a depletion analysis of the VTB GCMR. One of the essential ingredients is the depletion chain.

Upon examining the available chains, I noticed there are PWR and Fast Spectrum options. Since my reactor is thermal, the PWR chain seems more appropriate than the Fast Spectrum chain. Though this reactor isn’t truly a PWR, since it is Helium cooled and has YH2 as a moderator, whereas a PWR uses water for both.

I am not (yet) a depletion expert, so I’m wondering if there are extra isotopes that I should add to the CASL chain via openmc.deplete.Chain.add_nuclide(openmc.deplete.Nuclide), or if the CASL chain should be sufficient as is. Other possible differences between the GCMR and a PWR would be in the spectrum/Q-values/branching ratios, so maybe the isotopes in the CASL chain are fine, but the data could potentially need to be changed? I’m hoping not, though.

Any advice would be greatly appreciated!

Lewis

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Hi Lewis! The only thing in the depletion chain that is really specific to the spectrum is the capture branching ratios, which are used when capture may result in more than one product (e.g., Am241(n,γ) may result in Am242 or Am242_m1). So, even if you have a thermal spectrum reactor that’s not a PWR, the “PWR” chain should work just fine.

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