No neutrons due to spontaneous fission

_Geant4 Version:_11.1.2
_Operating System:_Ubuntu 22.04.4 LTS
_CMake Version:_3.22.1


I’m trying to score neutrons due to spontaneous fission from uranium fuel. I am able to score alphas successfully but I’m not getting any data for neutrons. I tried running example rdecay02 with macro u238c.mac which should model the decay of stationary u238 nuclei but I’m having the same problem where there are no neutrons scored in the secondary particle output file. In my own model I have implemented the physics list and biasing physics from rdecay02 and also used /process/had/rdm/BRbias true in my macro to switch on branching ratio biasing but no luck so far. Am I missing something?

Best wishes,