Plutonium Fraction

To assess the effect of the $\text{Pu}$ fraction among the heavy component influences on the functional a similar approach to the previous one can be applied. The same may also be done for the $^{235}\text{U}$ uranium enrichment. Firstly, a part of the previous example is reproduced.

import sauna

sensitivities = sauna.Sensitivities()
sensitivities.from_serpent('../../models/MET1000_FC_28_sens0.m')
pu_nuclides = [942360, 942380, 942400, 942410, 942420]

Next, heavy nuclides are provided as only they are accounted when fissile fraction is considered. It is also widely admitted that this fraction is a weight one, and the value has to be calculated beforehand.

heavy_nuclides = [922340, 922350, 922360, 922380, 932370, 942360, 942380,  
                 942400, 942410, 942420, 952410, 952421, 952430, 962420,
                 962430, 962440, 962450, 962460]
wo_239 = 0.10455

It is useful to note that here the list of heavy nuclides contains the nuclides of interest, but it should not as it is mentioned in the previous example. As a result, SAUNA automatically removes redundant nuclides. Having the inputs prepare, one calls a function, explicitly mentioning that the fraction type is 'wo'. In this example, the input uncertainty is assumed 1%, the same as in the previous example.

uncertainty_wo = sauna.Analysis.get_concentration_uncertainty(sensitivities    = sensitivities,
                                                              uncertainty      = 0.01,
                                                              targets          = target_nuclides,
                                                              background_zams  = heavy_nuclides,
                                                              fraction         = wo_239,
                                                              fraction_type    = 'wo',
                                                              uncertainty_type = 'normal')

The expected output is about 0.26% for the eigenvalue.