class openmc.deplete.SILEQIIntegrator(operator, timesteps, power=None, power_density=None, n_steps=10)[source]

Deplete using the SI-LE/QI CFQ4 algorithm.

Implements the Stochastic Implicit LE/QI Predictor-Corrector algorithm using the fourth order commutator-free integrator.

Detailed algorithm can be found in Section 3.2 in Colin Josey’s thesis.

  • operator (openmc.deplete.TransportOperator) – The operator object to simulate on.
  • timesteps (iterable of float) – Array of timesteps in units of [s]. Note that values are not cumulative.
  • power (float or iterable of float, optional) – Power of the reactor in [W]. A single value indicates that the power is constant over all timesteps. An iterable indicates potentially different power levels for each timestep. For a 2D problem, the power can be given in [W/cm] as long as the “volume” assigned to a depletion material is actually an area in [cm^2]. Either power or power_density must be specified.
  • power_density (float or iterable of float, optional) – Power density of the reactor in [W/gHM]. It is multiplied by initial heavy metal inventory to get total power if power is not speficied.
  • n_steps (int, optional) – Number of stochastic iterations per depletion interval. Must be greater than zero. Default : 10
  • operator (openmc.deplete.TransportOperator) – Operator to perform transport simulations
  • chain (openmc.deplete.Chain) – Depletion chain
  • timesteps (iterable of float) – Size of each depletion interval in [s]
  • power (iterable of float) – Power of the reactor in [W] for each interval in timesteps
  • n_steps (int) – Number of stochastic iterations per depletion interval
__call__(bos_conc, bos_rates, dt, power, i)[source]

Perform the integration across one time step

  • bos_conc (list of numpy.ndarray) – Initial concentrations for all nuclides in [atom] for all depletable materials
  • bos_rates (list of openmc.deplete.ReactionRates) – Reaction rates from operator for all depletable materials
  • dt (float) – Time in [s] for the entire depletion interval
  • power (float) – Power of the system in [W]
  • i (int) – Current depletion step index

  • proc_time (float) – Time spent in CRAM routines for all materials in [s]
  • conc_list (list of numpy.ndarray) – Concentrations at each of the intermediate points with the final concentration as the last element
  • op_results (list of openmc.deplete.OperatorResult) – Eigenvalue and reaction rates from intermediate transport simulation


Return pairs of time steps in [s] and powers in [W]


Return integer number of depletion intervals


Perform the entire depletion process across all steps