LCS error: bert.3 bert.2 when running BURN card MCNP

[Syifa S]

TL;DR Summary

I need help with MCNPX error: "LCS error: bert.3 bert.2 .... " when running a BURN card. Tried to expand the KSRC, but failed.

Hello,

I'm working on BURN UP analysis on a NuScale PWR with variations on U235 enrichment and the number of Gd2O3 burnable poisons rods used. I use KCODE and KSRC card as attached below. I'm having trouble with the error message on the output file. At first, I fixed that by increasing the number of KSRC I used, starting from the middle part of the core until expanding towards the outside of the core (but only on the middle assembly). But I ran into an error again. So I continued to expand the fuel pin used in the middle assembly, but there were still some variations that were not successful, only one or two variations succeeded. I also tried to use another fuel pin from another assembly, and I got the same result (I put the screenshot of the output file below). Does anyone know how to fix this?

^ above is the error message in the output file

^above is the reference I used to model the core

 

[Alex A]

Hi @Syifa S, welcome to Physics Forums. I am not he best person to answer but someone better qualified may see this later. This needed more than 10 GB space free, and I ran out of free space but I did not get that error. What version of X are you using and what version of the cross section libraries?

What error were you fixing by adding so many KSRC points?

 

[Syifa S]

Hi @Alex A, thank you for the reply.

I'm using the MCNPX 2.6.0 version and I use several libraries in the material card; endf-6.0, endf-6.6, endf-85, and endf-vi.5 (I attached the material card and "the print table 100" part from the output file below).

I encountered the same error when I first tried to run the assembly level. So I tried adding the KSRC points, and it worked, the error didn't occur. But when I tried to run in the core level, the error seemed to come up again. I tried adding more KSRC points, but it didn't work.

It seems the error occurred in several dump numbers. As I was adding the KSRC points, the dump numbers decreased, and the error appeared in those dump numbers.

I have under 10 GB of free space on my PC, but still got an error.

I already added all of the middle parts of the assemblies into the KSRC points, but the error still occurs. Any idea what might cause this?

 

[Alex A]

I tried again and the runt file grew to over 30GB but I have no trace of that error message. I think I only made one change to get it to work with my system - an OMIT line on a missing isotope entry. If this version fails it might be worth checking your libraries and xsdir entries. It might also be worth clearing more space and see if that affects anything.

I don't know why the LAHET Bertini model would even be used. Maybe it is to fill in missing table data. I had my machine hang due to a memory issue (caused by another program). There is a way to resume a problem but I'm not sure how to do it.

Best of luck!

 

[Syifa S]

Thank you @Alex A for the reply. I tried it again with OMIT added, but I still got the same error message. I also changed the libraries many times, hoping to trace what libraries might have caused the error, but it's no use. I still got the same error.

Is it possible that the specifications and capacity of the computer used influence the simulation results? If so, do you know what might be causing the error? And could I know the specifications of the computer or device you used to obtain those results?