Federal Guidance Documents: NRC Regulatory Guides, NUREGs, EPA & FDA Guidance
Key Takeaways
Regulations (10 CFR, 21 CFR, 29 CFR, 49 CFR) are binding; NRC regulatory guides and NUREGs describe methods the staff finds acceptable, and licensees may use other methods if they show a basis for compliance.
Key NRC medical guidance includes NUREG-1556 Vol. 9 (medical licenses), RG 8.39 (patient release), RG 8.20 (radioiodine bioassay), RG 8.13 (prenatal exposure instruction), and RG 8.40 (effective dose equivalent from external exposure).
EPA Federal Guidance Report 11 supplies the dose coefficients behind 10 CFR 20 Appendix B ALIs and DACs, FGR 13 gives cancer risk coefficients, and FGR 14 (2014) gives radiation protection guidance for diagnostic and interventional x-ray procedures.
The EPA Protective Action Guides recommend evacuation or sheltering at projected doses of 1–5 rem over 4 days and relocation at 2 rem in the first year; FDA potassium iodide thresholds range from 5 cGy projected thyroid dose for children to 500 cGy for adults over 40.
OSHA's 29 CFR 1910.1096 covers ionizing radiation sources not regulated by the NRC, with a basic whole-body limit of 1.25 rem per calendar quarter.
Federal Guidance Documents: NRC Regulatory Guides, NUREGs, EPA & FDA Guidance
A medical health physicist works from two kinds of federal documents. Regulations in the Code of Federal Regulations are binding law. Guidance explains how an agency interprets its regulations, offers acceptable methods, and records technical bases. Examinations often ask which document a requirement or value comes from, and practice depends on knowing when guidance can be replaced by another approach.
Regulation versus Guidance
| Type | Examples | Legal Status |
|---|---|---|
| Regulations | 10 CFR 19, 20, 35, 37, 71; 21 CFR 900 and 1020; 29 CFR 1910.1096; 49 CFR 171–178 | Binding; violations can bring enforcement |
| NRC Regulatory Guides (RGs) | RG 8.13, 8.20, 8.39, 8.40 | Methods the NRC staff finds acceptable; not required |
| NUREG reports | NUREG-1556 Vol. 9 (medical use licenses) | Licensing guidance and model procedures |
| License conditions | Commitments in an approved application | Binding on that licensee once incorporated |
| EPA Federal Guidance | Federal Guidance Reports, presidential guidance, PAG Manual | Guidance to federal agencies; technical basis for rules |
Regulatory Guide 8.20 states the principle directly: regulatory guides are not substitutes for regulations and compliance with them is not required, and methods that differ from them will be accepted if they provide a basis for the findings the NRC must make. A key subtlety is that a model procedure from a guide becomes binding when the licensee commits to it in its license application.
NRC Guidance for Medical Licensees
- NUREG-1556, Volume 9, Revision 3 (2019), Program-Specific Guidance About Medical Use Licenses: the licensing roadmap for 10 CFR 35, with model procedures for area surveys, spills (including Table N-1 major-spill amounts), leak tests, and training.
- RG 8.39, Revision 1: release of patients administered radioactive material, with default release tables, dose equations, and breast-feeding guidance.
- RG 8.20, Revision 2: applications of bioassay for radioiodine, with handling thresholds and action levels of 1 µCi and 5 µCi in the thyroid.
- RG 8.13: instruction concerning prenatal radiation exposure, describing the declared pregnant worker provisions of 10 CFR 20.1208.
- RG 8.40: methods for estimating effective dose equivalent from external exposure, including the two-dosimeter formulas used for workers wearing lead aprons.
- RG 8.29 (risks from occupational radiation exposure) and RG 8.7 (recording and reporting occupational dose) support worker instruction and records.
EPA Federal Guidance
The EPA issues guidance to federal agencies on radiation protection:
- Presidential guidance on occupational exposure (1987) set the federal framework, including the 50 mSv (5 rem) annual effective dose limit adopted in 10 CFR 20.
- Federal Guidance Report No. 11 (1988) provides inhalation and ingestion dose coefficients that underlie the ALIs and DACs in 10 CFR 20 Appendix B.
- FGR 12 gives external dose coefficients for radionuclides in air, water, and soil; FGR 13 gives cancer risk coefficients per unit intake or exposure.
- FGR 14 (2014), Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures, gives recommendations to federal facilities on justification, optimization, diagnostic reference levels, and qualified personnel, and is widely used as a model elsewhere.
- Protective Action Guides (PAG) Manual (2017): in the early phase of a radiological incident, evacuation or sheltering is recommended at projected doses of 1 to 5 rem (10–50 mSv) over 4 days, and relocation at 2 rem (20 mSv) projected in the first year, with a goal of 0.5 rem per year in later years.
FDA, OSHA, and Other Federal Guidance
- FDA potassium iodide guidance (2001): KI is recommended at projected thyroid doses of 5 cGy or more for children, adolescents, and pregnant or breast-feeding women, 10 cGy or more for adults 18–40, and 500 cGy or more for adults over 40.
- FDA public health advisory (1994) on avoiding serious x-ray-induced skin injuries during fluoroscopically guided procedures, an early milestone that preceded the 2006 FDA requirement for air kerma displays on new fluoroscopes.
- OSHA, 29 CFR 1910.1096: applies to ionizing radiation sources not regulated by the NRC or an Agreement State in workplaces under OSHA jurisdiction. Its basic limits are per calendar quarter: 1.25 rem whole body, 18.75 rem to the hands and forearms or feet and ankles, and 7.5 rem to the skin of the whole body, with an allowance of 3 rem per quarter if lifetime dose stays within 5(N − 18) rem.
Using Guidance in Practice
When an inspector, accreditation surveyor, or examination question cites a value, the physicist should ask: Is it a regulatory limit, a license commitment, or a guidance value? For example, 5 mSv to the embryo/fetus is a regulation (10 CFR 20.1208), 0.5 mSv per month is an NCRP recommendation, the 33 mCi I-131 release table value is RG 8.39 guidance, and a facility's wipe-test action level is a license commitment or internal policy.
A licensee wants to use a patient-release calculation method that differs from the one in NRC Regulatory Guide 8.39. Which statement is correct?
This is prohibited, because regulatory guides have the force of law once published and cannot be departed from.
It is allowed only if the Agreement State legislature amends its statute.
Regulatory guides apply only to reactor licensees, so medical licensees may ignore them and use any method.
It is acceptable if the method shows that the 10 CFR 35.75 dose criterion is met, because guides describe acceptable methods but are not requirements.
Which federal document supplies the dose coefficients that underlie the ALIs and DACs in 10 CFR 20 Appendix B?
The EPA Protective Action Guides Manual
NUREG-1556, Volume 9
EPA Federal Guidance Report No. 14
EPA Federal Guidance Report No. 11
Under the 2017 EPA Protective Action Guides, at what projected dose is evacuation or sheltering recommended in the early phase of a radiological incident?
1 to 5 rem (10–50 mSv) projected over 4 days
5 rem (50 mSv) projected over the 50 years following the incident
25 rem (250 mSv) projected over the first day
0.1 rem (1 mSv) projected over the first year
Sections you finish are checked off in the contents.