Re: the two final comments of our valued colleague, John Emit Dixon.
Modelling is the correct spelling; the author wishes to congratulate the ICRP committee members on their use of British and World English rather than American English for this international report.
In a transparent attempt at character assassination, the author also wishes to represent that in our valued colleague's comment, "The word modelling is miss-spelled.", it should read misspelled, both for British and American English.