Follow on decay calculation in ORIGAMI

[Clara Rojas]

Hello, I'm trying to run a decay calculation in ORIGAMI from a previous nodal calculation in ORIGEN. The previous case has just one axial zone, so I wrote in the input file that nz=1.

When I run the next input in ORIGAMI, it's not clear which "position" from the F71 file is taking to start the decay. I suppossed that the key "asmid=" correspond to the desired position in the isotopics file, but I was cheking that the result is not the expected one. 

Is this the right procedure to calculate isotopics in ORIGAMI from a previous case with the .f71 file? Could it be possible to do it?

Thanks!

[Steve Skutnik]

Hello Clara,

For follow-on "restart" decay cases, ORIGAMI can take in the previous isotopic inventories by zone in the *.assm.f71 concentrations file. So for example, say you had a decay case with 4 axial zones; for simplicity, we'll call this "axial.inp." So, when you run ORIGAMI, it will generate the collapsed axial zone concentrations (in order) in axial.assm.f71. This file will have five total entries: the first four are the four collapsed axial regions, and the fifth is the collapsed concentrations across the entire assembly (i.e., for all axial zones). This concentrations file (*.assm.f71) contains the last calculated depletion or decay step for each axial zone of the problem and then the collapsed assembly concentrations (i.e., it has only one time step for each of the axial zones, unlike the other .f71 file (in this case, just "axial.f71"), which has all saved timesteps for every pin / axial zone.

So, as far as your restart calculation goes, ORIGAMI will look for positions [1,NAX], where "NAX" is the number of axial zones specified in your restart case on the file "assembly_restart.f71". If you have only one axial zone for the restart, it will just take the first position on that file.

You may find Sample Problems 2 & 3 in the ORIGAMI manual to be helpful here; this gives an example of how to do exactly what you're trying to do. (This is on pages 5-220 to 5-228 of the SCALE manual).

-Steve

SCALE support team

[Clara Rojas]

Thank you so much Steve! I was checking and it's perfectly clear.

Thank you again. 

Clara.