Keyword:PATHRESET
PATHRESET showpathways
For inventory calculations with long cooling times, the dominant nuclides at late times may not be significant at the end of the irradiation phase, and this leads to poor estimates for the uncertainties. One remedy for this is to use the LOOKAHEAD keyword. In some instances, particularly where there are actinides in the source material, the look-ahead approach may lead to excessively large numbers of target nuclides in the pathways calculations.
The PATHRESET keyword provides an alternative means of including late-time dominant nuclides. Its inclusion leads to the pathways calculation being repeated in the cooling phase and this causes the late time dominant nuclides to be included in the uncertainty calculations. There are three values for the showpathways argument:
-1 display pathways for a target nuclide for which pathways have not been displayed at earlier times;
0 do not display pathways, but use the pathways in uncertainty estimates;
1 display pathways for all dominant nuclides at each pathways reset.
If the PATHRESET keyword is included in the initial conditions section of the input file, then pathways are recalculated at each step where there are new target nuclides, and all occurrences of the PATHRESET keyword in the inventory calculation phase are ignored. The recommended usage of this keyword is to use it where required in the cooling phase of the inventory calculation.
Example usage, where new pathways analyses are performed and output at each of the cooling steps. Note that the initial pathways are calculated at the ZERO instance, while PATHRESET calls a new calculation at each time that it is called:
< -- Control phase -- > ... FISPACT * Title of the simulation < -- Initial phase -- > ... UNCERTAINTY 2 FLUX 1.0E10 ATOMS < -- Inventory phase -- > TIME 1.0 HOURS ATOMS FLUX 0.0 ZERO < cooling periods > TIME 1.0 HOURS ATOMS PATHRESET 1 TIME 1.0 DAYS ATOMS PATHRESET 1 TIME 1.0 YEARS ATOMS PATHRESET 1 TIME 10.0 YEARS ATOMS PATHRESET 1 TIME 100.0 YEARS ATOMS PATHRESET 1 TIME 1000.0 YEARS ATOMS ...
