Energy. Part20:Standards for protection against radiation. Subpart C:Occupational Dose Limits. Section20.1203:Determination of external dose from airborne radioactive material.
Licensees shall, when determining the dose from airborne radioactive material, include the contribution to the deep-dose equivalent, lens dose equivalent, and shallow-dose equivalent from external exposure to the radioactive cloud (see appendix B to part 20, footnotes 1 and 2).