10 CFR Part 20 — Standards for Protection Against Radiation


In 2010, the Nuclear Regulatory Commission (NRC) held public workshops to solicit input on the potential changes to the NRC’s radiation protection regulations (10 CFR Part 20).  Three workshops were held; in Silver Spring, MD; Los Angeles, CA; and Houston, TX.  The NRC is reviewing its regulations for Occupational Dose Limits, Total Effective Dose Equivalent Calculations, and Doses to Special Populations. 

SNMMI is generally opposed to the NRC’s proposal to limit radiation worker annual doses to 20 mSv (2rem).  While it appears that a limiting to a 20 mSv (2 rem) dose limitation would affect only a relatively small portion of the worker population, there may be unintended consequences such as increased cost to patients and third party payers, a decrease in quality of care, and impacts on the ability of personnel to work except for short periods of time.

SNMMI was invited to have member representatives serve on the panels of all three workshops.  Additionally, SNMMI submitted formal comments in January, 2011, in response to a request by the NRC in February 2010.  Formal comments were developed detailing SNMMI’s position on the regulations and submitted in January 2011.

Current Status

On November 20, 2014, SNMMI submitted comments to the NRC on the advance notice of proposed rulemaking for 10 CFR Part 20. These comments address several issues in radiation protection including methodology and terminology, occupational dose limit for the lens of the eye, dose limit for embryo/fetus of a declared pregnant occupational worker, individual protection, metrication, and reporting of occupational exposure.

SNMMI’s comments were consistent with previous positions on these issues, with the exception of the occupational dose limit for the lens of the eye and adoption of new methodology and terminology. It is the opinion of this committee that the proposed decrease in occupational dose limit for the lens of the eye should likely be lowered to new standards as proposed by the ICRP publication “ICRP statement on Tissue Reactions in Normal Tissues and Organs – Threshold Doses for Tissue Reactions in a Radiation Protection Context.” New information regarding the threshold for cataracts appears to be lower than previously thought and should be acted upon. Despite cataracts being a surgically correctable disease, unlike most other radiation induced morbidities, it is felt that the efforts to reduce such disease can and should be enacted in its prevention.

Additionally, SNMMI recommends the adoption of the current methodology and terminology associate with effective dose and total effective dose as this is consistent with current publications in this regard even it may involve some level of effort to implement these changes. To date, the NRC has utilized the methodology as described in International Commission on Radiological Protection (ICRP) Report 26 and the definition of effective dose equivalent and total effective dose equivalent (EDE and TEDE) as opposed to effective dose and total effective dose (ED and TED) as described in ICRP Report 103.

If the NRC develops draft supporting guidance for a proposed 10 CFR Part 20 rulemaking, then the public will have an opportunity to provide comment on the draft guidance. If the NRC decides not to pursue a 10 CFR Part 20 rulemaking on this topic, the NRC will publish a document in the Federal Register that will generally address public comments and withdraw the Advanced Noticed of Proposed Rulemaking.