Section 218.2 - General proceduresThe following procedures govern the approach taken in dose determination:
(a) Use individual film badge data where available and complete, for determining the external gamma dose.(b) Identify group activities and locations for period(s) of possible exposure.(c) Qualitatively assess the radiation environment in order to delineate contaminated areas. If no activities occurred in these areas, and if no other potential for exposure exists, a no dose received estimate is made.(d) If partial film badge data are available, define group(s) of personnel with common activities and relationships to radiation environment.(e) Using standard statistical methods, verify from the distribution of film badge readings whether the badged sample adequately represents the intended group.(f) Calculate the mean external gamma dose, with variance and confidence limits, for each unbadged population. Assign a dose equal to 95% probability that actual exposure did not exceed the assigned dose.(g) If badge data is not available for a statistical calculation, conduct a dose reconstruction.(h) For dose reconstruction, define radiation environment through use of all available scientific data, e.g., measurements of radiation intensity, decay, radioisotopic composition.(i) Quantitatively relate activities shielding, position, and other factors to radiation environment as a function of time. Integrate dose throughout period of exposure.(j) Where possible, calculate mean dose with confidence limits; otherwise calculate best estimate dose or, if data are too sparse, upper limit dose.(k) Compare calculations with available film badge records to verify the calculated doses. Whether or not film badge data is available, calculate initial and internal doses where identified as a meaningful contribution to the total dose.