U.S. Nuclear Regulatory Commission
Question 372: When monitoring of internal exposure is required by 10 CFR 20.1502, 10 CFR 20.1204 (a) requires the licensee to take "suitable and timely" measurements. Will NRC define what is suitable and timely to avoid differences of opinion among inspectors?
Answer: No. Some general guidance on what is suitable and timely will be included in Regulatory Guide 8.9, Rev. l, "Acceptable Concepts, Models, Equations, and Assumptions for a Bioassay Program." Other than this general guidance, the NRC staff has no plans to provide a definition of what is "suitable and timely." That definition depends on the circumstances of the particular exposure. What is "suitable and timely" under revised Part 20 is (as before, under old Part 20) a matter of professional judgement in a good radiation protection program. NRC management will resolve any "differences of opinion among inspectors" that are called to its attention.
(References: 10 CFR 20.1204, 10 CFR 20.1502)