I also has same question about semi-transparent media.

semi-transparent media to "Participates In Radiation" 
boundary condition -> semi-transparent (Internal Emissivity 0.08)

The Internal emissivity is very small but I think the absorbed radiation flux should be bigger then 0.
From my result, surface incident radiation, reflected radiation flux has values.

Should I have to check case setting?
OR is this result normal for the semi-transparent media?