Set up time_step for depletion

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1

hello everyone, i want to do a depletion calculation for msr thermal reactor. power output msr is 350 MW. how to set the time step and time steps unit in openmc if i want to use unit MWd/kg?

Thank you,

2

You can define time steps in two ways,

one is to define directly

timesteps = [(1, ‘MWd/kg’), (2, ‘MWd/kg’),(2, ‘MWd/kg’) (this is 5MWd/KgHM burnup with 3 time step units)
integrator=openmc.deplete.PredictorIntegrator(operator, burnup, power = power, timestep_units=‘MWd/kg’)

& the second one is to use numpy array

import numpy as np
burnup = np.array([1,2,2]) (this is 5MWd/KgHM burnup with 3 time step units)
burnup = np.diff(burnup, prepend=0.0)
integrator=openmc.deplete.PredictorIntegrator(operator, burnup, power = power, timestep_units=‘MWd/kg’)

then run the depletion calculation. u’ll get the resultatnt keff value changes with time which is needed to be converted into MWd/KgHM

time t obtained from depletion result , (unit in s, convert it into days)
p=350MW
m= total mass of your system in Kg. (you can get it using operator.heavy_metal.

now burnup b = pt/m (MWd/Kg)

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3

thank you @imtiaj_hossain , your answer is very helpful