Health Physics Questions and Answers - Question 47

Question 47: Will the NRC provide guidance on preparation of applications pursuant to 10 CFR 20.1204 (c) (2) for approval to adjust DAC or ALI values to reflect the actual physical and chemical characteristics of airborne radioactive materials (e.g., aerosol size distribution or density)?

Answer: The NRC staff is considering developing such guidance. Some limited guidance on "adjusting DAC's for particle size" is included in draft Regulatory Guide 8.25, Rev. 1, Section 3.7; however, the staff recognizes that more extensive guidance, including considerations of other physical and chemical characteristics of particles, may be needed.

(Reference: 10 CFR 20.1204 (c) (2))