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Decay steps in automated burnup sequence

Posted: Tue Aug 22, 2017 3:37 pm
by jan.frybort
Hi.
I would find it useful to make branch-off calculations in the automated burnup sequence from decay steps. Would it be possible to add some option to specify such states in the coefficient matrix? Thank you.
Jan

Re: Decay steps in automated burnup sequence

Posted: Tue Aug 22, 2017 5:39 pm
by Jaakko Leppänen
Actually, if you enter negative values in the coef-card, Serpent should interpret them as decay time (in days). This way you should be able to run branches for decay steps. I don't think I've ever tried this feature myself, so let me know if it doesn't work.

Re: Decay steps in automated burnup sequence

Posted: Wed Aug 23, 2017 3:00 am
by jan.frybort
Thank you for your reply. I tried that and it is working. I have the following depletion specification:

set powdens 39.69E-3
dep butot
1
dep decstep
1
dep butot
10
dep decstep
1

and coefficient matrix:

coef 5 0 1 -2.61953E+01 10 -2.53953E+02

It is only inconvenient that I needed one error try to learn from the Serpent error messages the available burnup points in the restart file. Is it to get a list of the available burnup points?

Re: Decay steps in automated burnup sequence

Posted: Wed Aug 23, 2017 9:47 am
by Jaakko Leppänen
Try commenting out the coef card and add an rfr entry with some burnup that doesn't exist. That should give you the list of available points.

Re: Decay steps in automated burnup sequence

Posted: Wed Aug 23, 2017 2:59 pm
by jan.frybort
You are right. It gave the list of burnup points. It would be nice to have some switch for Serpent to give the list of the burnup points in a restart file.

Re: Decay steps in automated burnup sequence

Posted: Tue Mar 27, 2018 3:34 pm
by jan.frybort
Jaakko Leppänen wrote:Actually, if you enter negative values in the coef-card, Serpent should interpret them as decay time (in days). This way you should be able to run branches for decay steps. I don't think I've ever tried this feature myself, so let me know if it doesn't work.
Dear Jaakko, I am currently testing some restart calculations. My depletion calc. has following steps:

Code: Select all

dep butot 0.1 0.5 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
          11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0
          21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 29.0 30.0
set powdens 0.0
dep decstep 365.25
I would like to restart from the depletion step by setting RFR in restart input

Code: Select all

set rfr -365.25 A40E63D.wrk
But it Serpent2.1.30 complains that it does not know such state:

Code: Select all

Restart file "A40E63D.wrk" contains the following burnup points:

 0 : BU =   0.000 MWd/kgu, time = 0.00000E+00 days
 1 : BU =   0.100 MWd/kgu, time = 2.51953E+00 days
...
31 : BU =  29.000 MWd/kgu, time = 7.30663E+02 days
32 : BU =  30.000 MWd/kgu, time = 7.55858E+02 days

***** Tue Mar 27 14:14:19 2018

Input error:

Burnup point 365.250 days not found in restart file
Is it possible to restart from a depletion step? Thank you.
Jan Frybort

Re: Decay steps in automated burnup sequence

Posted: Wed Mar 28, 2018 1:30 pm
by Jaakko Leppänen
The "dep decstep" entry means that you add a 365.25 day decay step after the previous burnup steps have been completed. So to make a restart after the decay step, you need to enter the total number of days up to that point.

Re: Decay steps in automated burnup sequence

Posted: Wed Mar 28, 2018 2:05 pm
by jan.frybort
Thank you. I tried changing the restart point to 1121.108 d (755.858+365.25) but Serpent still complains about non existent burnup point:

Code: Select all

Burnup point 1121.108 days not found in restart file
Jan Frybort

Re: Decay steps in automated burnup sequence

Posted: Thu Mar 29, 2018 3:01 pm
by Jaakko Leppänen
You should get a list of points that are available. Can post that?

Re: Decay steps in automated burnup sequence

Posted: Thu Mar 29, 2018 3:09 pm
by jan.frybort
That list is in my message from March 27. I only omitted middle points, but otherwise the list is complete.
Jan Frybort