|Overall a very useful document, although a bit overwhelming in size. I would suggest that the main text could be shorted with much of the detail moved to suitable annexes. In particular, it is confusing to split parts of the staged approaches between the main text and the annexes. I feel it would be useful for each stage to have its own annex, with a short overview of the stages within the main text.
Specific Comments (all relatively minor)
May be worth expanding the definitions to include the Latin terms such as in Vivo, in vitro etc
Section 4.2 – May be worth covering briefly the differences of efficiency between germanium and sodium iodide detectors.
Section 8 – I found it confusing having the stages split between the main text and an annex. Worth noting that for an acute intake, such as following an incident all routes have to be considered, as frequently the intake will be due to unexpected actions/events.
Section 8.2 – Not sure if you have mentioned considering maximum uncertainty