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?