General Comments:
1) This document advances the science of radiation effects on biota beyond that provided in ICRP Publication 108. However, it is not certain that further refinement of the science is essential to provide adequate protection to populations of biota surrounding nuclear/radiological facilities. It should be recognized that some regulatory bodies still use the presumption that protection of people provides adequate protection of biota. In the majority of circumstances this presumption provides adequate protection. ICRP 108 provided, and this document will provide, a methodology for analysis to provide greater assurance of protection of biota. Given the virtually limitless number of biota species, it should be recognized that, while of academic interest, from a standpoint of environmental protection there is a point where further refinement is not cost beneficial.
2) The document needs to have a table explaining abbreviations and acronyms.
Specific Comments:
Line 252: It is stated here that the goal of assessment is to "prevent or reduce radiation effects among living organisms". This seems to infer protection of individual organisms. A more appropriate goal is to protect populations of an organism from significant and irreversible damage.
Line 318-319: It is noted here that the uncertainties in modelling transfer factors and intake of organisms can significantly exceed the uncertainties in DCs. Given this, consideration should be given to the benefit of further refinement of DCs.
Line 495: Additional explanation of the circumstances where the capability to estimate doses to a receptor 500 meters above the ground surface would be used would be helpful here. The application this feature is not apparent.