The Source Scenario screen appropriately calculates the DF based on the user input Pin Pressure (psig). However, the DF is incorrectly limited to a value between 1 and 200. There is no such limitation in RG 1.183 Rev. 1, Appendix B.
Further, the calculated DF should only be applied to the elemental iodine while organic iodine should be assumed to have a DF of 1 (unmitigated) and CsI is fully retained in the Phase 1 release (0-2 hrs) and assumed to fully dissociate to be released as re-evolved elemental iodine from 2 hrs to 30 days. It is not clear to me that this is implemented correctly; it appears that the calculated DF is applied as an overall Iodine DF, more consistent with Rev. 0 guidance.