5-MWe - nuclear archaeology

This notebook presents a script that uses the functionalities of the nuclear archaeology module of ONIX to find the isotopic ratios that are the most sensitive to fluence in the 5-MWe reactor. In a practical setting, using these isotopic ratios allows to measure fluence with minimal unertainties. This script uses neutronics results from the simulation "5-MWe - reactor simulation" in the Reactor Simulations section from the examples in this documentation.

import onix.nax as nax

---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-1-4419ce8565d1> in <module>
----> 1 import onix.nax as nax

ModuleNotFoundError: No module named 'onix'

First we specify the path of the simulation from which we are going to use neutronics results such as one-group cross sections and one-group neutron flux.

path1 = '/home/julien/Insync/jdtdl@stanford.edu/GoogleDrive/Stanford/DPRK-NAX-paper/simulations/test2_25MW_07BU_kang-geo_sample/'

Next, we need to specify the name of the BUCell in the 5-MWe reactor from this simulation in which we want to analyze isotopic ratios and fluence sensitivity. In this case, we are studying

NAX_cell = 'Sample'

We now need to define a vector of days that indicates the length of each cycle of operation of the 5-MWe reactor.

Here, burnup sequences are converted into days using the power and the IHM (Initial Heavy Metal) of the NAX_cell previously defined. Three sets of burnup sequence are considered (following different hypothesis on operation history of the 5-MWe reactor). One assumes high burnup levels, another low burnup levels, and a last one the average of both.

pow_unit_cell = 6.00000E-05
ihm = 118.75970682995882*1E-3

burnup_list_low = [0.6, 0.23, 0.22, 0.22, 0.23]
burnup_list_high = [0.699, 0.33, 0.31, 0.31, 0.32]
burnup_mid = [(i+j)/2 for i,j in zip(burnup_list_low, burnup_list_high)]

day_list = []
for bu in burnup_mid:
    day = bu*ihm/pow_unit_cell
    day_list.append(day)

We now create a “reference batch” that will be used to construct the whole operation history of the 5-MWe reactor using the previously defined list of operation cycles length. This “reference batch” stores relevant neutronics results that will be used to study isotopic ratios fluence sensitivity.

batch1 = nax.Batch(path1)

Using the previously defined “reference batch”, we create a list of operation cycles where the length of each of these cycle is indicated in day_list and the neutronics parameters are taken from batch1. This constitues the operation history of the reactor.

operation_history = []
for day in day_list:
    batch = (batch1, day)
    operation_history.append(batch)

Finally, we call the NAX function that will deplete the NAX_cell with neutronics parameters taken from the selected simulation according to an operation history defined in operation_history

nax.review_all_ratio_candidates(NAX_cell, operation_history, path1, 1E-3)