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Fatal error in function VolumesMC

Posted: Sun Mar 21, 2021 1:38 pm
by ahmed
Hello everyone.

i faced the following fatal error when tried to calculate the material's volumes, even with using command "set lost -1", and when I drew the figures there were no errors. Does anyone know what I should do ?

Fatal error in function VolumesMC
Pointer error: value 0 below minimum = 1052 (ptr)
Simulation aborted.

Re: Fatal error in function VolumesMC

Posted: Sun Mar 21, 2021 2:41 pm
by Ana Jambrina
That error pops up as a result of a pointer issue at any 'CheckPointer' call within 'volumemc.c' routine when scoring a point estimator or looping over an unstructured-mesh based geometry. Most likely, it is related with a problem in the geometry ('lost' option should not be used to avoid errors due to incomplete defined geometries). - Which Serpent version are you running and what type of geometry did you defined (e.g. unstructured-mesh based, STL-mesh based, CSG-based)?

Re: Fatal error in function VolumesMC

Posted: Sun Mar 21, 2021 4:32 pm
by ahmed
Thanks a lot Ana for quick response.
I am using Version 2.1.32 , and i attached my input file, you can see which kind of geometries i used to define the reactor's zones.

Re: Fatal error in function VolumesMC

Posted: Sun Mar 21, 2021 4:38 pm
by Ana Jambrina
There are some modifications in volumemc.c routine in Serpent 2.1.32 related with unstructured-mesh based geometry. Since your model is not built on such type of mesh, the problem does not come from a potential bug from the latest version. As I mentioned before, most likely, the error arises from a geometry/material problem.

The problem might not only show up when calculating volumes through '-checkvolumes' command line option; it might also appear while tracking particles during inactive/active cycles. (The 'lost' option might help allowing the calculation to go through, however might hide a geometry problem).

Try running the input in DEBUG mode to get additional info from where the problem might come:

Code: Select all

Tracking error: cell search error (possibly undefined region)

(x,y,z)  = -2.34244E+01 -1.77655E+01 -4.48543E+01
(u,v,w)  = -7.83747E-01 -6.08200E-01  1.25832E-01

Lost particles: 1

Checking geometry errors (this may fail)...

Geometry error: undefined region.

Geometry structure at last position is printed below.
Some levels may not be printed correctly. Look for the
first level that fails: undefined region, suspicious
local coordinates, etc., and check the corresponding
geometry definition in the input.

Level 0 / universe 0 :
Cell universe / overlap or undefined cell
(x,y,z)  = -2.34244E+01 -1.77655E+01 -4.48543E+01
(u,v,w)  = -7.83747E-01 -6.08200E-01  1.25832E-01
Note: check the definition material air (wrong library ID), nuclide 6013 and 8018 are not included in ENDF/B-VII library.

Re: Fatal error in function VolumesMC

Posted: Sun Mar 21, 2021 6:30 pm
by ahmed
Thanks a lot Ana, i found the problem, and calculated the volumes.

thank you very much.