This mod has been updated to version 1.2

http://www.fallout3nexus.com/downloads/file.php?id=15215

1. Bug Fix: Follower Fatigue restored at Quest end.
2. Bug Fix: Correct HHG manufature time based on the number you found.
3. Bug Fix: Correct perk radiation regeneration only when your hurt.
4. Update: Shower in bathroom heals 5 hp per second.

NOTE:
If you previously played the mod, I added a switch on the wall to the right of the Holy Hand Grenade manufacture terminal. Click that and all the fixes above will take effect.

is this mod compatible with arwen realism tweaks?
thank you

I don't know what Arwen Realisim tweaks does. But it should be compatible with just about everything.