Gas Production

This model computes the production of gaseous species (stable or radioactive) from fission and tracks the cumulative amount produced over time. The calculation is performed separately for each gas System defined in sciantix_system (e.g., Xe, Kr, He, and selected isotopes), and it supports both the standard fuel matrix and the high-burnup structure (HBS) region.

The implementation follows Simulation::GasProduction().

Inputs

For each gas system, the model uses:

  • system.getProductionRate(): production rate of the gas (source term).

  • Time step (physics variable): current integration step size.

Activation

The gas production routine is invoked for all defined gas systems each time step. Systems with a zero production rate will not change but are still processed consistently by the loop.

Outputs

  • <GasName> produced (cumulative produced inventory)

  • <GasName> produced in HBS (when applicable)

Model resolution

For each gas system, SCIANTIX creates a model entry named:

  • Gas production - <system name>

and stores as parameters:

  • the production rate,

  • the time step.

The cumulative produced amount is updated by time integration using solver.Integrator:

\[P^{n+1} = P^{n} + \dot{P}\,\Delta t\]

where:

  • \(\dot{P}\) is the gas production rate for the system,

  • \(\Delta t\) is the current time step,

  • \(P\) is the cumulative produced inventory.

Depending on whether the system belongs to the standard matrix or to the HBS (restructured matrix flag), the result is written to different variables:

  • If system.getRestructuredMatrix() == 0:

    • <GasName> produced is updated.

  • If system.getRestructuredMatrix() == 1:

    • <GasName> produced in HBS is updated.

Implementation note

The routine loops over all systems in sciantix_system, so gas production is handled consistently for all modelled gaseous species using the same integration scheme.