WARNING: Particle 1 underwent maximum number of events.

User Support
1

Hello,
as mentioned before im trying to simulate assembly for VVER1000 reactor and after great help from Mr.Paul Romano i was able to write the geometry for it , but unfortunately when im try to run K Eigen Value simulation i get this error WARNING: Particle 1 underwent maximum number of events.
attached below my input file in case i write some thing wrong in my input
the thing that i couldn’t do it is in MCNP im able to make all assembly surface’s reflected in order to run in infinite instead of finite , but i don’t know how it could be done in Openmc
Thanks

geometry.xml (6.26 KB)

materials.xml (1.54 KB)

settings.xml (402 Bytes)

2

Hi Ahmed,

The problem here is that your model extends to infinity with a void material. When particles reach the edge of the core, they will just stream forever and eventually OpenMC quits because there is a hard limit on the number of events a particle is allowed to undergo (in this case, too many surface crossings). What you need to do is create six surfaces that bound the hexagonal lattice. Two of these will be x-planes, and the others need to be general planes. Use those surfaces to set the region of cell 1 (in which you are filling the hexagonal lattice), and make sure you have boundary=“reflective” on those surfaces.

Best,
Paul

3

Dear Prof:Paul

i did as same as you told me but im facing problem that value that im getting are very small , im calculating keff for VVER 1000 fuel assembly , i added six reflective surface to contain the hexagonal lattice the values that im getting are in range 0.01 which is very small to the one that should be attached my input file
Thanks

geometry.xml (6.58 KB)

materials.xml (1.54 KB)

4

Hello, Ahmed,
I also meet the same problem with you, [Particle underwent maximum number of events]
Have you figured it out? Hope to get your help!

Best regards,
Benjamin

在 2017年4月9日星期日 UTC+8上午5:08:14，Ahmed K. Madani写道：