Time evolution of Dose Rate using USRTRACK

Hi everyone,

I have come across an odd behaviour in the output of USRTRACK scoring when I score dose rate in a given volume. Using
the DCYSCORE card, I look at gamma dose rate at different cooling times. I am including the cards for two cooling times
only (0 sec and 30 days after EOB).

USRTRACK -1. DOSE-EQ -35. rTaConv 100.DEPTa0s
USRTRACK 0.05 1E-4 &
DCYSCORE 5. DEPTa0s USRTRACK

USRTRACK -1. DOSE-EQ -36. rTaConv 100.DEPTa30d
USRTRACK 0.05 1E-4 &
DCYSCORE 9. DEPTa30d USRTRACK

AUXSCORE USRTRACK PHOTON DEPTa0s DEPTa30d AMB74

When looking through the usrtrack output file for either unit (I have attached test_usrtrack_35_tab.lis),
I see a series of energy intervals with zero for dose rate and rel. error, before the results are shown for the energy
interval I selected in the scoring.

Does anyone know why this happens?

Thanks in advance,
Mina