1 

Advisory Committee on the Medical Use of Isotopes (ACMUI) 

Comments on the Nuclear Regulatory Commission (NRC) 

Advanced Notice of Proposed Rulemaking (ANPR) 

on Potential Changes to Radiation Protection Regulations 

Final Report: January 29, 2015 

Subcommittee Members: F. Costello; V. Dilsizian; S. Langhorst (Chair); S. Mattmuller; and P. 

Zanzonico 

Charge: To provide recommendations and answers to the specific questions and issues identified 

by NRC in the ANPR1

 in its development of a draft regulatory basis for possible revision of the 

NRC’s radiation protection standards.

General Recommendations

Issue Paper 1 – The ACMUI supports updating 10 CFR Part 20 to align with the International 

Commission on Radiological Protection Publication (ICRP) 103 methodology and terminology. 

Issue Paper 2 – The ACMUI supports change of the occupational dose limit for the lens of the eye 

to 50 mSv (5 rem). 

Issue Paper 3 – The ACMUI does not support change of the dose limit for the embryo/fetus of a 

declared pregnant occupational worker from 5 mSv (500 mrem). 

Issue Paper 4 – The ACMUI does not support revising or adding regulatory requirements regarding 

a licensee’s as low as reasonably achievable (ALARA) program. 

Issue Paper 5 – The ACMUI supports the change to use of the International System of Units (SI) in 

radiation protection regulations, but recognize the need by some licensees to have a reasonable 

period of time to transition from the use of conventional units. 

Issue Paper 6 – The ACMUI does not support expansion of additional categories of licensees that 

should be required to submit annual occupational exposure reports under 10 CFR 20.2206(a). 

Cumulative Effects of Regulation – The ACMUI recommends NRC use a similar implementation 

plan as that used for the last significant change of 10 CFR Part 20 in 19912 where the licensee could 

choose to implement the regulatory change anytime within a given time frame. The Committee 

recommends a time frame of at least three years to allow implementation of procedure, training, 

hardware, and software changes needed to comply with the new regulatory requirements.

 

1

 79 FR 43284, July 25, 2014, Docket ID NRC-2009-0279. 

2

 56 FR 23360, May 21, 1991. 
2 

Issue Paper 1 

Update 10 CFR Part 20 to Align with the International Commission on 

Radiological Protection Publication 103 Methodology and Terminology 

Comments

The NRC’s regulations currently use the term, “total effective dose equivalent (TEDE),” to 

represent the summation of doses received from external and internal radiation sources and thereby 

express the total stochastic radiation risk. As part of its development of the draft regulatory basis 

for the update of 10 CFR Part 20, the NRC will consider revising the regulations in 10 CFR Part 20 

and making associated changes to its other regulations to incorporate the ICRP term, “effective 

dose.” Effective dose, the tissue-weighted sum of the equivalent doses (i.e., the sum of the products 

of the tissue absorbed doses from different radiations R and the respective radiation weighting 

factors wR) in all specified tissues and organs of the body, reflects the overall probability of 

radiogenic stochastic risk, namely, of cancer induction and genetic (germ-line) mutation. It takes 

into account the type of radiation (in terms of the radiation weighting factors wR) and the nature 

(i.e., susceptibility to stochastic damage) of each organ or tissue irradiated (in terms of tissue 

weighting factors wT). The concept of effective dose was originally proposed in 19753. It was then 

included as “effective dose equivalent (HE)” in ICRP publication 264. In 1991, ICRP publication 60 

shortened the name to "effective dose." (This quantity is sometimes incorrectly referred to as the 

"dose equivalent" because of the earlier name, and that misnomer in turn causes confusion with 

equivalent dose.) The tissue weighting factors were revised in 1990 (ICRP publication 60)5

 and 

2007 (ICRP publication 103)6 as updated radiation epidemiology data became available. It is 

recognized that the effective dose is misused at times, specifically, to estimate the stochastic risk to 

specific irradiated individuals. Nonetheless, effective dose is now the standard quantity used 

internationally as well as in the United States to express overall stochastic radiation risk7. The 

TEDE, still in place in current NRC regulations, is an outdated quantity and is no longer used or 

encountered other than in the NRC’s regulatory literature and it is therefore strongly 

recommended that the NRC revise its regulations in 10 CFR Part 20 and its other regulations 

to incorporate the effective dose in place of the TEDE.

ICRP publication 1036 superseded ICRP 264, and the dosimetry revisions from ICRP 

publication 26 to ICRP publication 103 included changes in the values of both the radiation and 

tissue weighting factors (wR and wT, respectively) used to calculate the effective dose. As noted, 

the tissue weighting factors were revised in 1990 (ICRP publication 60)5 and 2007 (ICRP 

publication 103)6

. The NRC’s draft regulatory basis will consider replacing the specified 

values of the weighting factor in 10 CFR 20.1003 with those of the tissue weighting factors in 

 

3

 Jacobi W. The concept of effective dose - A proposal for the combination of organ doses. Radiat Environ Biophys 12: 

101–109, 1975. 

4

 1977 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP. ICRP 

publication 26 1 (1), 1977. 

5

 1990 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP. ICRP 

publication 60 21 (1-3), 1991. 

6

 2007 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP. ICRP 

publication 103 37 (2-4), 2007. 

7

 Brenner DJ. Effective dose: A flawed concept that could and should be replaced. Br J Radiol 81: 521-3, 2008. 
3 

Table 3 of ICRP Publication 1038 and replacing the quality factors in Table 1004(b).1 and 

Table 1004(b).2 of 10 CFR 20.1004, “Units of Radiation Dose,” with the radiation weighting 

factors in Table 2 of ICRP Publication 1038 together with other associated changes (e.g., 

replacing “dose equivalent” with the term “equivalent dose” and replacing TEDE with 

effective dose). The foregoing changes are strongly recommended. 

The transition from ICRP publication 269 to ICRP publication 1038 also included changes in 

the underlying isotope-specific biokinetic models used to determine organ absorbed doses following 

intakes of radionuclides. Changes to the biokinetic models since ICRP publication 26 have 

included a new respiratory tract model (ICRP publication 6610) and, more recently, a new human 

alimentary tract (HAT) model (ICRP publication 10011). The biokinetic models can have a 

significant impact on calculated organ dose conversion factors (DCFs) (i.e., absorbed dose per unit 

activity administered or otherwise internalized; also known as dose coefficients) and thus on 

calculated effective doses. The conversion to ICRP publication 103 biokinetic models would 

therefore not be without a certain “overhead”: the current ICRP biokinetic models and DCFs may 

lead to revision of at least some the annual limits on intakes (ALIs) and limits on derived air 

concentrations (DACs) etc. in Appendix B to 10 CFR Part 20 and this, in turn, may have a financial 

impact on licensees and other stakeholders in order to comply with the revised limits. It is 

nonetheless recommended that the NRC revise its regulations in 10 CFR Part 20 to 

incorporate the latest isotope-specific biokinetic models and associated DCFs in ICRP 

publication 1038

.

The human body can now be realistically modeled as a complex set of mathematical and 

“voxel” phantoms as a result of advances in medical imaging and computer technology since the 

1991 10 CFR Part 20 rulemaking12. These advances have resulted in the development of age- and 

gender-specific reference computational phantoms for dosimetry in addition to adult males: 1-yearold, 5-year-old, and 10-year-old children and 15-year-old males and females8,13. The ICRP is 

considering the use of corresponding age- and gender-weighted DCFs for developing a set of 

environmental intakes of radionuclides. The NRC is likewise considering the use of the age- and 

gender-averaged approach to provide a more realistic representation of a member of the public that 

explicitly considers the presence of infants and children within the population. The use of age- and 

gender-averaged DCFs, based on the set of ICRP reference computational phantoms, for 

establishing regulatory limits on environmental intakes of radionuclides is recommended. 

The use of age- and gender-specific DCFs for regulatory purposes should not be considered, 

however, as it is inappropriate for radiological protection of the general public and would 

excessively burden licensees. 

 

8

 2007 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP. ICRP 

publication 103 37 (2-4), 2007. 

9

 1977 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP. ICRP 

publication 26 1 (1), 1977. 

10 Human Respiratory Tract Model for Radiological Protection. Annals of the ICRP. ICRP publication 66 24 (1-3), 

1994. 

11 Human Alimentary Tract Model for Radiological Protection. Annals of the ICRP. ICRP publication 100 36 (1-2), 

2006. 

12 56 FR 23360, May 21, 1991. 

13 Adult Reference Computational Phantoms. Annals of the ICRP. ICRP publication 110 39 (2), 2009. 
4 

The NRC continues to use the linear-no-threshold hypothesis for radiation risk in guiding its 

regulatory limits and controls. While the National Research Council’s Board on Radiation Effects 

Research (BEIR) concluded in the 2006 BEIR VII Report14 that current scientific evidence is 

consistent with the hypothesis that there is a linear, no-threshold dose-response relationship between 

exposure to ionizing radiation and the development of cancer in humans, the National Research 

Council Nuclear and Radiation Studies Board is currently evaluating plans to develop an updated 

BEIR VIII report15 and the Health Physics Society (HPS) continues to hold the following position16

regarding radiation risk: 

“There is substantial and convincing scientific evidence for health risks following high-dose 

exposures. However, below 50–100 mSv (which includes occupational and environmental 

exposures), risks of health effects are either too small to be observed or are nonexistent.” 

Specific Answers

Q1–1: What are the implications of changing the NRC’s regulations to specify ‘‘total effective 

dose’’ in place of the current term ‘‘total effective dose equivalent?’’ To the extent possible, please 

provide specific implementation and operational cost information on the impacts of this change 

relative to licensee procedures, training, recordkeeping, and reporting. This information is 

necessary for the NRC to determine whether the imposition of such requirements on NRC licensees 

is justified. 

A1–1: “Effective dose” is, by definition, a summation or total, and so the phrase “total effective 

dose” should not be used. The effective dose is now the standard quantity used internationally as 

well as in the United States to express overall stochastic radiation risk. The TEDE is an outdated 

quantity and is no longer used or encountered other than in the NRC’s regulatory literature. The 

effective dose and TEDE are, however, both metrics of overall stochastic risk and thus conceptually 

similar. They differ largely in technical detail: (a) the TEDE uses the quality factor, QF, while the 

effective dose uses the radiation weighting factor, wR, to adjust for differences in linear energy 

transfer (LET) and in stochastic risk-related biological effectiveness among different radiations; (b) 

the TEDE and the effective dose use different tabulations of the tissue weighting factor, wT, to 

adjust for differences in sensitivity to stochastic risks among different tissues. Transformation of 

TEDE, the current quantity, to effective dose, the proposed quantity, amounts to an arithmetic 

transformation, therefore. This, in turn, will require updating of software and/or hardcopy forms 

used to record and otherwise manage personnel exposures in a facility’s radiation protection 

program. Any such updates are not without some financial and logistical impact but in this instance 

 

14 Health Risks from Exposure to Low Levels of Ionizing Radiation BEIR VII Phase 2. Committee to Assess Health 

Risks from Exposure to Low Levels of Ionizing Radiation. Board on Radiation Effects Research, Division on Earth and 

Life Studies, National Research Council of the National Academies, The National Academies Press, Washington, DC, 

2006. 

15 Planning Towards the BEIR VIII Report. Board on Radiation Effects Research, Division on Earth and Life Studies, 

National Research Council of the National Academies, The National Academies Press, Washington, DC, 2006 

(http://dels.nas.edu/Upcoming-Event/Planning-Towards-BEIR-VIII-Report/AUTO-0-14-84-B?bname=nrsb, last 

accessed January 3, 2015). 

16 Radiation Risk in Perspective. Position Statement of the Health Physics Society (PS010-2), Adopted January 1996, 

Revised July 2010 (http://hps.org/hpspublications/positionstatements.html, last accessed January 3, 2015). 
5 

the impact should be minimal. Furthermore, the quantitative differences between the calculated 

TEDE and effective dose in specific instances are generally quite minor and generally should not 

impact a facility’s operation. That is, an occupationally exposed individual who would exceed a 

regulatory maximum permissible dose (MPD) or an associated institutional action level if the dose 

were expressed in effective dose would also do so if it were expressed in TEDE. Likewise, an 

individual whose dose would not exceed a MPD or action level if the dose were expressed in 

effective dose would not exceed the MPD or action level if the dose were expressed in TEDE. 

Overall, replacing the TEDE with the effective dose in NRC regulation and thereby aligning the 

NRC’s regulatory language with that use nationally and internationally is justified. 

Q1–2: If the NRC adopts the dose assessment terminology and methodology of ICRP Publication 

103 (2007) in a future rulemaking, what time period should the NRC consider providing for 

implementation of the ICRP Publication 103 (2007) methodology and terminology? 

A1–2: As noted above, adoption by the NRC of the dose assessment terminology and methodology 

of ICRP Publication 10317, in principle, should be logistically and conceptually straightforward. In 

practice, however, this conversion will involve updating of the applicable software and forms. The 

potential difficulties in updating, de-bugging, and testing and re-testing software, even for 

seemingly straightforward updates, should not be underestimated. For this reason, a minimum of 

three years is recommended for implementation of the ICRP Publication 10317 methodology and 

terminology. 

Q1–3: How should the calculation of effluent concentrations, currently in the 10 CFR part 20 

radiation protection regulations, be modified to reflect advances in modeling that are now 

available? In particular, the NRC is interested in preliminary views on the age and gender 

averaged approach.

A1–3: The calculation of effluent concentrations should be modified to reflect the latest set of 

ICRP reference computational phantoms18,19 and regulatory limits on effluent concentrations should 

be based on age- and gender-averaged DCFs derived from these phantoms. For public 

health/regulatory purposes, the use of such average DCFs for establishing regulatory limits on 

effluent concentrations is logical, as the general public represents an average population composed 

of both genders and of a distribution of ages from newborns to adults. The use of age- and genderspecific DCFs for regulatory purposes should not be considered, however, as it is inappropriate for 

radiological protection of the general public and would be impractical to implement. 

 

17 2007 Recommendations of the International Commission on Radiological Protection". Annals of the ICRP. ICRP 

publication 103 37 (2-4), 2007. 

18 2007 Recommendations of the International Commission on Radiological Protection". Annals of the ICRP. ICRP 

publication 103 37 (2-4), 2007. 

19 Adult Reference Computational Phantoms. Annals of the ICRP. ICRP publication 110 39 (2), 2009. 
6 

Q1–4: Should the public dose limit of 0.5 mSv (50 mrem) continue to be the basis for the effluent 

concentration limits for the radionuclides in 10 CFR Part 20, appendix B, Table 2, Columns 1 and 

2? Should it be reduced or otherwise modified? 

A1–4: As noted above, quantitative differences between the calculated TEDE and effective dose in 

specific instances are generally quite minor, despite the distinct sets of tissue weighting factors, 

wTs, used to calculate these respective quantities. Likewise, DCFs derived from the latest set of 

ICRP reference computational phantoms are not dramatically different from earlier DCFs. 

Accordingly, revision of a public dose limit of 0.5 mSv (50 mrem) as the basis for the effluent 

concentration limits for the radionuclides in 10 CFR Part 20, Appendix B, Table 2, Columns 1 and 

2 is not warranted. 

 
7 

Issue Paper 2 

Occupational Dose Limit for the Lens of the Eye 

Comments

The ACMUI supports change of the occupational dose limit for the lens of the eye to 50 

mSv (5 rem). This reduction of lens dose limit is anticipated to have minimal on medical licensees 

or on licensees that support medical use of byproduct material (support licensees), except for 

several very specific radiation personnel populations. Those personnel who work with byproduct 

materials and related instrumentation and are exposed to non-uniform radiation fields such that their 

eye doses are higher than their whole-body doses may require additional eye shielding and/or 

personal dosimeters to specifically measure lens dose. Certain personnel whose eyes are exposed to 

radiation from byproduct materials and fluoroscopic x-ray sources, such as interventional 

physicians involved in radioembolic therapy of liver tumors, may be impacted by this dose limit 

reduction. 

Specific Answers

Q2–1: Is closer alignment with or adoption of the ICRP Publication 118 (2012) recommendations 

regarding the dose limits to the lens of the eye appropriate given the scientific information now 

available? 

A2-1: Yes. Recent human epidemiological studies have suggested that opacification of the lens of 

the eye, or a “radiation cataract”, may occur at significantly lower doses of ionizing radiation than 

previously estimated. These include studies of Chernobyl nuclear reactor accident cleanup workers 

as well as radiologic technologists, interventional radiologists, and cardiologists. Of course, 

individual genetic and other differences in radiosensitivity among various exposed individuals may 

explain the variation in reported timing of the onset of cataract, degree of lens opacification, and 

subsequent progression to visual disability. 

Q2–2: How should the impact of a radiation-induced cataract be viewed in comparison with other 

potential radiation effects? 

A2-2: Unlike other potential radiation effects (fatal cancer, non-fatal cancer, or hereditary effects), 

radiation-induced eye lens injuries involve reduced transparency of the lens (cataract), which can be 

effectively treated by surgery. However, prevention (rather than treatment) should be the goal. 

There are three predominant forms of cataract, nuclear, cortical, and posterior sub-capsular, defined 

on the basis of the anatomical location in the eye lens. Ionizing radiation is generally (though not 

exclusively) associated with posterior sub-capsular opacities, while age-related cataracts are most 

commonly found in the nuclear region and cortical cataracts are commonly found in diabetic 

patients. Treatment of cataracts involves surgical removal of the opacified lens, leaving the capsule 

that contains it intact, and insertion of a plastic lens. 
8 

Q2–3: What mechanisms could be applied to keep the cumulative exposure to the lens of the eye 

below the threshold of 0.50 Gy (50 rad)? 

A2-3: Personnel only exposed to byproduct materials – Mechanisms to minimize exposure to the 

lens of the eye are the same as those employed for all external exposure to the personnel – time, 

distance and shielding. As noted in NRC Inspection Procedure 8353320, licensees need to evaluate 

radiation fields for dose gradients and have procedures in place to monitor non-uniform radiation 

fields. Medical radiation workers who handle higher activity sources, such as radiopharmaceuticals 

or brachytherapy sources, are not typically exposed to greatly different radiation fields between 

their whole body and lens of the eye, but personnel who do repair or maintenance of cyclotrons 

may be impacted by reduction of the lens occupational dose limit. 

Personnel exposed to byproduct materials and x-ray sources – Due to non-uniformity of radiation 

fields, personnel involved in fluoroscopic x-ray procedures will also be impacted by reduction of 

the lens occupational dose limit regulated by State radiation control programs which adopted the 

150 mSv (15 rem) occupation lens dose limit. Interventional radiologists performing 90Y 

microsphere therapies and perhaps some cardiologists who still perform intravascular brachytherapy 

procedures are the cohorts of byproduct material and x-ray personnel most likely to be affected, 

more so by their overall x-ray radiation exposures rather than those from the byproduct material 

they use. 

For fluoroscopic x-ray personnel, there are three categories of eye protectors that can be applied to 

minimize the cumulative exposure to the lens of the eye. It is important to point out, however, that 

these protective measures should be implemented along with maintaining x-ray fluoroscopy 

equipment (used to guide 90Y microsphere brachytherapy procedures) in optimum operating 

condition in order to minimize radiation exposure to the personnel. 

The three categories of shielding for fluoroscopically-guided interventional radioembolization 

procedures are as follows: 

1) Portable/moveable transparent scatter-shielding (leaded glass) screen, commonly suspended from 

the ceiling. These devices protect the entire head, and not just the eyes. 

2) Protective eyewear (e.g. leaded glasses) for personal use. These come in a variety of choices that 

can be individualized for the individual’s correct optical prescription, comfort and performance. 

3) Personal protection suit that is made up of leaded acrylic face shield (protecting the eye) and 

apron (replacing the heavy lead apparel), with the operator connected to the suit through a 

lightweight magnetic vest worn by the operator. The overhead, suspended design floats lead in 

front of the user instead of requiring them to wear it and has 1.00-mm lead-equivalent thickness, 

better protecting the body compared to the 0.5-mm thickness of older-style lead aprons. 

 

20 NRC Inspection Manual, Inspection Procedure 83533, Part 52, External Occupational Exposure Control and Personal 

Dosimetry, Issue Date 10/27/10. 
9 

For physicians and trainees who are directly involved with the interventional microsphere 

brachytherapy procedures that use fluoroscopy (interventional radiology), the use of eye protection 

should be “mandatory”. For the ancillary staffs in the interventional radiology suite (nurses, 

technologists, etc.) that are within a high-scatter X-ray radiation field and at least 3 feet away from 

the table (with an estimated exposure typically 10-fold less than those at the table), the use of eye 

protection should be “recommended”. 

Q2–4: What methods should be allowed for measurement or assessment of the dose to the lens of 

the eye?

A2-4: The current most widely used method for measuring or assessing the dose to the lens of the 

eye is a body dosimeter which is worn at the point of highest exposure. For personnel only working 

with byproduct material, lens dose estimated from the body dosimeter is a conservative measure if 

radiation fields are fairly uniform. If there is significant non-uniformity in the radiation field in 

terms of the body versus the eye dosimeters, those personnel may need to utilize “eye-specific” 

dosimeters usually worn with a head strap above the eyebrows and near the eyes, to provide better 

measure of the lens dose. 

For personnel performing fluoroscopic x-ray procedures, a collar body dosimeter placed outside any 

radiation protective garments provides an estimate the lens dose. If there is significant nonuniformity in the radiation field in terms of the collar versus the lens of eye, those personnel may 

likewise need to utilize “eye-specific” dosimeters unless that non-uniformity is due to eye shields 

with a known shielding reduction factor. 

Q2–5: What methods should be allowed for recording dose to the lens of the eye when the eyes are 

protected?

A2-5: For personnel doing fluoroscopic x-ray procedures, it would be reasonable to apply the 

industry-reported estimates for the shielding reduction factor to the lens of the eye for the three 

categories of eye protectors: 1) scatter-shielding transparent screen, 2) personal leaded eye glasses, 

and 3) personal protection suit with a face shield. Direct monitoring of eye dose, for example, by 

use of small semi-conductor detectors clipped onto eye glasses, would be an ideal approach, but 

there are currently limited data on this method. 

In a relatively busy interventional suite at a major inner-city academic institution, the estimated 

annual dose to the lens of the eye without the use of eye protection ranges from 40 to 80 mSv (4 to 

8 rem). It is estimated that the use of personal leaded glasses alone would reduce the lens dose rate 

by a factor of 5 to 10, and scatter-shielding screens alone would reduce the dose rate by a factor of 5 

to 25. Use of both glasses and shields simultaneously should therefore reduce the dose rate by a 

factor of 25 or more. Recent whole-body and lens personal protection suits with a face shield, with 

1-mm lead equivalence, may decrease the dose rate by a significantly higher factor, albeit at a much 

greater operational cost. 
10 

Q2–6: What are the potential operational impacts of lowering the annual occupational dose to the 

lens of the eye from the current NRC regulatory standard of 150 mSv (15 rem) to 50 mSv (5 rem)? 

Would a reduction in the occupational dose limit for the lens of the eye require changes in 

programs, procedures, practices (e.g., increased use of protective eyewear), or in-room shielding? 

If so, please describe these changes, including any potential implementation and operational costs.

 

A2-6: The potential operational impact of lowering the annual occupational dose to the lens of the 

eye from 150 mSv (15 rem) to 50 mSv (5 rem) would certainly require changes in fluoroscopic xray safety programs, making the use of an eye protector shield or personal leaded glasses a 

“mandatory” practice for interventional physicians/trainees at the table and “recommended” for the 

ancillary staff. This would have implications on operational costs and on enforcement for x-ray 

safety programs. 

Regarding costs, the portable/moveable transparent scatter-shielding screen option is estimated to 

cost less than $10,000 per shield, the personal leaded glasses approximately $400/person, and the 

personal protection suit with a face shield nearly $70,000 per unit; for 2 operators in the room, the 

purchase of 2 units per interventional room would be required. 

Q2–7: What are the potential impacts on State regulatory programs of a reduction in the 

occupational dose limit to the lens of the eye from the current NRC regulatory standard of 150 mSv 

(15 rem) to 50 mSv (5 rem)? 

A2-7: Regarding enforcement, it starts with implementing the change through the institutional 

Radiation Safety Committee and its Human Use Subcommittee and subsequent enforcement by the 

institution’s Environmental Health Services and Radiation Safety Officer. Of course, these changes 

would have implications for State radiation control programs that established an occupational lens 

dose limit of 150 mSv (15 rem), and perhaps on annual inspection and QA programs of The Joint 

Commission and the Centers for Medicare & Medicaid Services (CMS).

 
11 

Issue Paper 3 

Dose Limit for the Embryo/Fetus of a Declared Pregnant Occupational Worker 

Comments

The ACMUI recommends that the dose limit to the embryo/fetus (i.e., for the total dose of 

the duration of the pregnancy) of a declared pregnant woman not be changed from the current limit 

of 5 mSv (500 mrem) [10 CFR 20.1208]. The Committee’s recommendation is based on the 

following considerations. 

Scientific Basis of Risk

 The risk of cancer from in utero radiation exposure is a controversial subject. Exposure to 

ionizing radiation represents an oncogenic risk to the embryo/fetus, but the magnitude of the risk is 

unclear. The risks cannot be estimated accurately because of conflicting data and an inability to 

make precise risk estimates21. 

Recent publications and analyses indicate that the apparent risk is lower for the irradiated 

embryo than the irradiated child, and that there may be no increased carcinogenic risk from 

diagnostic radiological studies22. The Radiation Effects Research Foundation (RERF) continues to 

track the mortality and cancer incidence among survivors of the 1945 atomic bombings of 

Hiroshima and Nagasaki, including those who were exposed in utero and during early childhood. A 

recent RERF article23 concluded both the in utero and early childhood groups exhibited statistically 

significant dose-related increases in incidence rates of solid cancers, but the apparent difference in 

excess absolute rates (EARs) of childhood and adult cancer incidence between the two groups 

suggests that lifetime risks following in utero exposure may be considerably lower than for early 

childhood exposure. Further follow-up is needed. 

An additional, practical argument against a 100-mrem regulatory dose limit is that it would 

be within the range of variability encountered among natural background doses accrued annually 

across the United States. A regulatory dose limit within this range would thus be problematic, as it 

would be difficult to reliably distinguish an actual excess 100-mrem dose from the background dose 

itself. 

 The ACMUI does not support a lowering of the NRC dose limit from 5 mSv (500 mrem) to 

1 mSv (100 mrem) based on the current scientific knowledge of stochastic risk to the embryo/fetus 

of a declared pregnant woman. 

 

21 Brent, R.L. and Mettler, F.A., “Letters – Pregnancy Policy,” American Journal of Roentgenology. 2004;182: 819-822. 22 Brent, R.L., “Saving lives and changing family histories: appropriate counseling of pregnant women and men and 

women of reproductive age, concerning the risk of diagnostic radiation exposures during and before pregnancy,” 

American Journal of Obstetrics & Gynecology (January 2009). 23 Preston DL, Cullings H, Suyama A, et al., “Solid cancer incidence in atomic bomb survivors exposed in utero or as 

young children.” J Natl Cancer Inst 2008;100:428-36. 
12 

Alignment with Recommended Standards

In SECY-12-006424, the NRC staff recommended an option to develop the detailed draft 

language for changes to 10 CFR 20 that would achieve a greater degree of alignment with current 

scientific information, and with international recommendations and standards. The NRC Advisory 

Committee on Reactor Safeguards (ACRS) recommended that rulemaking to revise limits for 

occupational radiation exposure not be taken25. The Commission disapproved the staff’s 

recommendation in Option 3 to develop the regulatory basis to reduce the occupational total 

effective dose equivalent26. However, both the ACRS and the Commissioners supported staff’s 

continued discussion on dose limits for the embryo/fetus radiation exposure. 

The National Council on Radiation Protection and Measurements (NRCP) recommends a 

dose limit of 0.5 mSv (50 mrem) equivalent dose in a month once pregnancy is known27. The 

NCRP recently updated and expanded its recommendations regarding radiation exposure to 

pregnant and potentially pregnant women28. This NCRP report concluded that formal declaration of 

a pregnancy by a pregnant worker permits supervisors, if necessary, to take steps to control 

occupational exposure to radiation to less than that normally received, and that any risks from 

occupational exposure are considered minimal as long as the regulatory dose limits are met. This 

NCRP report does not recommend a change from the previous 1993 recommendation for the dose 

limit to the embryo/fetus of a declared pregnant woman29. 

Commissioner Magwood commented that alignment with international standards and 

practices is not, in and of itself, an appropriate goal for the NRC30. The ACMUI agrees with 

Commissioner Magwood’s comment, especially in light of the NCRP’s continued recommendation 

for a dose limit of 0.5 mSv (50 mrem) equivalent dose in a month once pregnancy is known, which 

is consistent with the current 10 CFR 20.1208 limit. 

Applications of Public Dose Limits and Individual Dose Limits

The NRC regulations require licensees to demonstrate compliance with dose limits for 

individual members of the public by considering the individual likely to receive the highest dose or 

for an individual continuously exposed [10 CFR 20.1302 and Appendix B Table 2]. These 

 

24 NRC SECY-12-0064, “Recommendations for Policy and Technical Direction to Revise Radiation Protection 

Regulations and Guidance” (April 25, 2012). 

25 NRC Advisory Committee on Reactor Safeguards, “Letter on SECY-12-0064” (October 16, 2012). 26 NRC SRM-SECY-12-0064, “Staff Requirements - SECY-12-0064” (December 17, 2012). 

27 NCRP (1993). National Council on Radiation Protection and Measurements. “Limitations of Exposure to Ionizing 

Radiation,” NCRP Report No. 116 (National Council on Radiation Protection and Measurements, Bethesda, Maryland). 

28 NCRP (2013). National Council on Radiation Protection and Measurements. “Preconception and Prenatal Exposure: 

Health Effects and Protective Guidance,” NCRP Report No. 174 (National Council on Radiation Protection and 

Measurements, Bethesda, Maryland). 

29 NOTE: Description of the NRCP 174 dose limit recommendation was incorrect in “Issue Paper 3 – Dose Limit for 

the Embryo/Fetus of a Declared Pregnant Occupational Worker,” (79 FR 43293, July 25, 2014). 

30 NRC Commission Voting Record, “Staff Requirements - SECY-12-0064” (December 17, 2012). 
13 

unrealistic circumstances, along with the low dose limit of 1 mSv (100 mrem), relieves licensees 

from having to consider what possible exposures each member of the public may receive from other 

licensees. Essentially, the NRC public dose limits are applied as design criteria. In the case where 

a member of the public may be more specifically identified and their exposure individually 

controlled and deemed appropriate, NRC allows use of an individual dose limit of 5 mSv (500 

mrem) [10 CFR 20.1301(d)]. There are three criteria that the NRC requires to approve an increase 

in the public dose limit from 100 mrem to 500 mrem: (1) “the need for and expected duration of 

operations in excess of the limit”; (2) “the licensee’s program to assess and control dose within the 

0.5 rem (5 mSv) annual limit”; and (3) “the procedures to be followed to maintain the dose as low 

as is reasonably achievable”. 

In the case of a declared pregnant worker, the radiation worker is specifically identified, 

may be required to be individually monitored [10 CFR 20.1502], and may have other occupational 

exposures included for the current calendar year [10 CFR 20.2104]. The pregnant worker’s 

exposure is individually controlled by virtue of her radiation worker training and the licensee’s 

ALARA program. 

The ACMUI does not consider it appropriate to apply a dose limit used as a design criterion 

for an unidentified individual who may be unaware of possible radiation exposure to an identified 

and often monitored radiation worker who is pregnant. 

Specific Answers

Q3–1: Are there any significant anticipated impacts associated with reducing the dose limit to the 

embryo/fetus of a declared pregnant woman, including operational impacts? What are the potential 

implementation and operational costs? 

A3–1: Several negative impacts associated with reducing the dose limit to the embryo/fetus of a 

declared pregnant woman were described in SECY-12-006431: 

“Several stakeholders indicated that a more restrictive limit could result in an increase in 

individuals choosing not to declare their pregnancy, in order to ensure their continued 

employment. This issue was raised specifically in the medical context, where it was stated 

that medical students, residents, etc. would not want to have any impacts on achieving their 

degree and requirements. Some stakeholders went so far as to suggest that the requirements 

could result in an inappropriate bias in the selection of female applicants. Statements were 

also made that there could be an increase in non-compliance, with individuals choosing not 

to wear proper dosimetry, etc.” 

The ICRP notes that changes in a declared pregnant woman’s radiation work responsibilities carries 

with it an ethical consideration in that another worker will have to incur additional radiation 

exposure because a co-worker became pregnant32. 

 

31 NRC SECY-12-0064, “Recommendations for Policy and Technical Direction to Revise Radiation Protection 

Regulations and Guidance” (April 25, 2012). 
14 

Q3–2: Are there any benefits or impacts associated with applying the reduced dose limit over the 

entire gestation period, or only to the period after declaration?

A3–2: Based on experience since 1991, the ACMUI recommends that no change be made to the 

current 10 CFR 20.1208(a) requirement to ensure the dose limit is applied to the entire pregnancy. 

Q3–3: Are there any anticipated implementation impacts on recordkeeping if the dose limit to the 

embryo/fetus is lowered to 1 mSv (100 mrem)? What are the potential implementation and 

operational costs?

A3–3: NRC requires each licensee to use individual monitoring devices for adults likely to exceed 

10% of their occupational total effective dose equivalent (TEDE), and for minors and declared 

pregnant women likely to exceed 1 mSv (100 mrem) TEDE. The requirement for a licensee to 

consider prior occupational exposure would be extremely difficult to demonstrate a reduced 

embryo/fetus dose limit for a worker who was not required to be assigned an individual monitoring 

device. Licensees would be more likely to experience and need to investigate potential 

mathematical “over exposures” with a lowering of this dose limit to a level comparable to 

environmental variability resulting in excess program expenditures and undo worker concerns in 

comparison to any averted risk. 

Q3–4: Are there technological implementation issues, such as limits of detection, which would 

make adoption of the ICRP Publication 103 (2007) recommendation difficult in certain 

circumstances?

A3–4: While the limit of detection for individual monitoring devices designed to measure deep 

effective dose equivalent (EDE) has improved in the past few decades, the levels actually measured 

are of the order of daily background radiation doses and thus are more susceptible to inaccuracies 

introduced from varying background doses subtracted from the individual monitoring devices. 

Reduction of the embryo/fetus dose limit would likely require a licensee to transition from relying 

only on the EDE measurement from individual monitoring devices to applying a correction factor to 

account for dose to the embryo/fetus based on a monitoring device positioned at the pregnant 

woman’s waist. ICRP states that its recommended dose limit applies to the fetal dose and it is not 

directly comparable to the dose measured on a personal dosimeter but can overestimate the fetal 

dose by a factor of 25 for nuclear medicine workers32. 

Q3–5: Are there data on actual dose distributions to the embryo/fetus of a declared pregnant 

worker? What are the trends for these data?

 32 ICRP (2000). International Commission on Radiological Protection. Pregnancy and Medical Radiation, ICRP 

Publication 84, Ann. ICRP 30(1) (Elsevier, New York). 
15 

A3–5: The ACMUI does not know of a source of data other than that gathered by vendors providing 

individual monitoring devices. Based on our collective anecdotal knowledge, EDE measurements 

from individual monitoring devices assigned to declared pregnant women remain well below 5 mSv 

(500 mrem) over the gestation period.

 
16 

Issue Paper 4 

Individual Protection – ALARA Planning 

Comments

The current Part 20 requires ALARA programs but does not provide specific ALARA 

planning and implementation requirements and so allows licensees to design ALARA requirements 

that are most appropriate to their enterprise. The best methodology would be to maintain the status 

quo and not impose any further prescriptive requirements. Defining what may be “reasonably 

achievable” is an inherently subjective process. The risks and safety cultures of different industries 

and different licensees within the same industry differ so much that providing the same compliancebased requirements on all licensees will not be effective. Furthermore, if the NRC were to decide to 

impose prescriptive ALARA requirements on its own licensees, there should be greater flexibility 

provided to the Agreement States in promulgating their own regulations to keeping occupational 

doses ALARA. For this reason, any proposed ALARA should be Compatibility C. 

Specific Answers

Q4–1: What are the potential implications of adding specific ALARA planning and implementation 

requirements to the 10 CFR part 20 regulations? What changes to licensee radiation protection 

programs could be anticipated? What would be the potential implementation and operational 

costs?

A4–1: No additional specific ALARA planning and implementation is needed for the 

overwhelming majority, if not all, of the medical users of radioactive materials. These licensees 

rarely experience situations where workers’ doses approach regulatory limits. Many of them 

already utilize administrative control levels (ACLs) to maintain doses ALARA. However, it is not 

necessary to add specific ALARA planning and implementation requirements to the 10 CFR part 20 

regulations. Safety cultures differ from licensee to licensee and there should be flexibility provided 

for the implementation of ALARA at each facility 

There are classes of users of machine-produced radiation that may benefit from specific ALARA 

planning and implementation but they are state-regulated, rather than NRC-regulated. 

Q4–2: What regulatory language should be used for an additional ALARA planning requirement 

and what is the rationale for this language?

A4–2: Safety cultures differ among licensees and there should be flexibility provided for the 

implementation of ALARA at each facility. It is important that licensees’ ALARA programs be 

designed to be effective for each licensee and for each group of workers there. Specific ALARA 

planning requirements would simply add an additional regulatory burden without improving the 

implementation of the licensee’s ALARA program. 
17 

Q4–3: How does each of the described methodologies for addressing when an individual 

occupational worker approaches his or her cumulative dose for the year work for different classes 

of licensed uses (e.g., a worker at a nuclear reactor power plant versus an industrial radiographer 

versus medical personnel)? What are the benefits and impacts of the various approaches to ALARA 

planning on the various types of licenses? 

A4–3: It is very rare that medical personnel using radioactive materials approach a dose limit. 

There is no need for additional approaches to ALARA planning for these types of licenses, 

therefore. There are cases at commercial PET cyclotrons where the engineers do receive whole 

body and extremity doses that can approach regulatory limits. However, even for these cases, the 

best approach is to retain the current Part 20 ALARA requirement and leave it to the licensee to 

develop ALARA procedures that are consistent with its own specific safety culture. 

Q4–4: Should licensees be allowed to establish different ACLs for different groups of occupational 

workers? If so, what should be the basis for the various groupings? 

A4–4: Licensees should be allowed to establish different ACLs for different groups of occupational 

workers. The basis should be a review of the historical doses for these groups and a consideration 

of what is “reasonably achievable”. The safety culture at each institution should form the basis for 

determining the appropriate ACL for each group. 

Q4–5: How do the different methodologies previously discussed impact the ability of licensees to 

best address radiation protection within their programs?

A4–5: The current Part 20 requires ALARA programs but does not provide specific ALARA 

planning and implementation requirements and so allows licensees to design ALARA requirements 

that are appropriate to their business. The best methodology would be to maintain the status quo 

and not impose any additional prescriptive requirements. 

Q4–6: Other than the methodologies discussed in the preceding section, are there other ways to 

evaluate occupational lifetime cumulative exposures that should be considered? 

A4–6: Since the Commission has decided not to impose a lifetime limit for occupational exposure, 

there is no compelling justification for establishing ALARA limits for workers whose lifetime 

exposure is approaching some arbitrary guideline. 

Q4–7: What are the potential impacts to licensees, contractors, and dosimetry vendors of 

amending 10 CFR 20.2104 to require a licensee to account for exposure from an occupational 

worker’s concurrent employment with another licensee? Are there any dosimetry vendors that 

provide concurrent dose records? Should the NRC consider provisions that would require 
18 

individual occupational workers to provide their occupational dose information in addition to 

requiring such information from licensees? 

A4–7: The current 10 CFR part 20 already has sufficient requirements for a licensee to determine 

the exposure form an occupational worker’s concurrent employment with multiple licensees. It is 

the responsibility of licensees to work with their employees and the dosimetry vendors to facilitate 

their compliance with the requirements listed below. 

10 CFR 20.1201(f) requires that a “licensee shall reduce the dose that an individual may be 

allowed to receive in the current year by the amount of occupational dose received while 

employed by any other person”. 

10 CFR 20.2104(a) requires that, “for each individual who is likely to receive an annual 

occupational dose requiring monitoring under § 20.1502, the licensee shall determine the 

occupational radiation dose received during the current year”. 

10 CFR 20.2104(c) states that “in complying with the requirements of paragraphs (a) or (b) 

of this section, a licensee may— 

(1) Accept, as a record of the occupational dose that the individual received during the 

current year, a written signed statement from the individual, or from the individual's most 

recent employer for work involving radiation exposure, that discloses the nature and the 

amount of any occupational dose that the individual may have received during the current 

year; 

(2) Accept, as the record of cumulative radiation dose, an up-to-date NRC Form 4, or 

equivalent, signed by the individual and countersigned by an appropriate official of the most 

recent employer for work involving radiation exposure, or the individual's current employer 

(if the individual is not employed by the licensee); and 

(3) Obtain reports of the individual's dose equivalent(s) from the most recent employer for 

work involving radiation exposure, or the individual's current employer (if the individual is 

not employed by the licensee) by telephone, telegram, electronic media, or letter. The 

licensee shall request a written verification of the dose data if the authenticity of the 

transmitted report cannot be established”. 

 
19 

Issue Paper 5 

Metrication – Units of Radiation Exposure and Dose 

Comments

The SRM-SECY-12-006433 states that the regulations should maintain both 

traditional units and the International System of Units (SI). 

To those who support a complete transition to SI units this can be seen as a 

regulatory constraint. The United States will unfortunately continue to use dual units 

while the rest of the world continues to use only SI units. The resistance to conversion 

within the U.S. can perhaps best be defused by this statement in the Health Physics 

Society (HPS) Position Statement on SI Units34: 

“Nearly all countries in the world, many with well-established nuclear 

industries, have effected this transition successfully, without compromising 

health and safety, and have demonstrated that complete conversion to current 

international units is certainly practical and doable.” 

In the Commissioners SECY-12-006435 they state in section 7) Units of Radiation 

Exposure and Dose: 

“The same public communication and emergency response communication 

issue remain as they were in 1995. These issues were highlighted during the 

response to the Fukushima event, where there was confusion resulting from the 

use of different units.” 

This statement appears to be in conflict with the very essence of the NRC, as stated on 

the “About NRC” web page36: 

“...to ensure the safe use of radioactive materials for beneficial civilian 

purposes while protecting people and the environment.” 

Confusion arising from the use of different units during an emergency is contrary to the 

NRC’s mission, especially when their use is avoidable. This would seem to be an 

unassailable reason as to why the NRC should convert. The SRM-SECY-12-006432

regulatory “constraint” is in place, that is 10 CFR Part 20 already contains both units. 

The following answers to the three questions will be answered within the following 

 

33 NRC SRM-SECY-12-0064, “Staff Requirements - SECY-12-0064” (December 17, 2012). 

34 Exclusive Use of SI Units to Express Radiological Quantities. Position Statement of the Health Physics 

Society (PS025-0), Adopted February 2012 (http://hps.org/hpspublications/positionstatements.html, last accessed 

January 3, 2015). 

35 NRC SECY-12-0064, “Recommendations for Policy and Technical Direction to Revise Radiation Protection 

Regulations and Guidance” (April 25, 2012). 

36 http://www.nrc.gov/about-nrc.html, last accessed January 3, 2015. 
20 

context. The use of both units will be used consistently throughout the regulations (with 

emphasis on the SI unit) as a means to effect the transition to the sole use of SI units in 

the future. 

Specific Answers

Q5–1: Will promulgation of amendments to the 10 CFR part 20 regulations with dose 

limits and other measurements shown in dual units, with the SI units shown first, 

followed by the traditional units in parentheses, cause an undue burden or hardship 

upon any licensee or class of licensees? If so, please explain and provide examples, 

including any potential implementation or operational costs.

A5–1: To paraphrase the HPS statement above, there are no real burdens or hardships as 

all nations other than the U.S. have already accomplished the transition to SI units. 

Consider the Chinese. Not only did they complete the conversion but also did so across 

two different alphabets, having converted SI units from the Latin alphabet to their Pure 

logographic alphabet, as shown in the following example: 

SI in Chinese: 

Bq = 放射性活度 

Q5–2: Should 10 CFR 20.2101(a) be revised to allow licensees the option of providing 

records in SI units or in traditional units? Should licensees be allowed to provide 

reports in the units used in licensee records? Should licensees be required to record 

and report in both sets of units? Please provide reasons why or why not.

A5–2: 10 CFR 20.2101(a) should be revised so licensees always provide records in SI 

units; if desired, they may also report in traditional units in parentheses. They should 

do the same when they submit reports, that is, providing the quantity in SI units first, 

and then, if desired, traditional units second and in parentheses. Licensees may thus 

use both sets of units; however, this should not be required. 

According to the Department of Transportation, currently within the U.S. over four 

million radioactive material packages and their related records are already prepared 

and shipped each year using SI units without imposing any real burden or hardship. 

Revising the regulations in this manner would be consistent with and facilitate the 

transition to SI units in the future. 

Q5–3: Should the NRC amend the appendices for 10 CFR Part 20 to show values in SI 

units only, in traditional units only, or in both sets of units? If both SI and traditional

units are provided, which set of units should be considered as the regulatory standard? 

If only one set of units is specified, what would be the most effective means to provide the 
21 

other set of units (e.g., in a separate guidance publication)? Please provide reasons 

why or why not. 

A5–3: To be consistent with SRM-SECY-12-006437 the appendices should be amended 

to show values in both units, with the SI unit considered as the regulatory standard. 

Values in both sets of units could be easily displayed, especially in the electronic version 

of the regulation. While a printed version of the appendices with both set of units would 

be cumbersome, the practical effect would be negligible, as the NRC web site has 

already demonstrated the advantages of the electronic version of the appendices. The 

electronic version of the appendices allows the regulatory information to be readily 

available, and in a form easier to find and far easier to read than the printed version. In 

addition it has already found a solution for the metrication conversion by listing the SI 

value with three significant digits, as it did with appendix A to 10 CFR Part 37. 

Additional reliance on the electronic version of the regulations is consistent with the 

Government Printing Office’s own efforts to strive to keep all informed in the digital 

age. 

The NRC has already taken a major step in the metrication conversion with the 

appendices. The last time they were revised the concentration values in 

traditional/traditional units, for example mCi/firkins* were converted to a hybrid of 

traditional and SI units, mCi/mL. Complete conversion to SI/SI units is the next logical 

step.

* The old traditional unit for volume used in the appendices is not known. A firkin (a volume 

unit describing a small barrel of beer that is one-fourth the size of a regular barrel of beer) was 

chosen as an example of an out-dated traditional unit. 

 

 

37 NRC SRM-SECY-12-0064, “Staff Requirements - SECY-12-0064” (December 17, 2012). 
22 

Issue Paper 6 

Reporting of Occupational Exposure 

Comments

 The ACMUI does not believe there is need to expand the number of license categories 

required to submit annual occupational exposure reports to the NRC because of the low average 

occupational doses associated with medical-use licensees and licensees which support them. 

Medical licensees, as well as other material licensees, as allowed under 10 CFR 20.1502, choose not 

to monitor many radiation workers individually who receive low occupational doses. Requiring 

national occupational dose tracking of those radiation workers who do require individual 

monitoring could lead to unrealistically high estimates of average occupational doses for medical 

licensees and other material licensees’ radiation workers. 

 The ACMUI does not believe that NRC should act as the nation’s repository of occupational 

radiation exposure data, as the NRC does not have regulatory authority over all ionizing radiation 

sources. While it would be helpful to gather all occupational radiation exposure data for all material 

licensees meeting the current 10 CFR 20.2206(a) criteria, the ACMUI cannot provide a specific 

recommendation as we do not know enough about the resources needed for Agreement States to 

gather these data nor the NRC’s regulatory authority to require Agreement State material licensees 

to submit annual occupational exposure reports directly to the NRC. 

Specific Answers

Q6–1: What criteria should the NRC use to identify additional categories of licensees that should 

be required to submit annual occupational exposure reports under 10 CFR 20.2206(a)? 

A6–1: The NRC states in the 2012 occupational radiation exposure report38 that the principal uses 

of these data “...are to provide facts regarding routine occupational exposures to radiation and 

radioactive material that occur in connection with certain NRC-licensed activities.” In addition, the 

NRC staff uses the data for the following purposes: 

• “Evaluation of licensee’s radiation protection and as low as reasonably achievable 

(ALARA) efforts. 

• Assist in evaluation of radiological risk and comparative analyses of radiation protection 

performance between license categories. 

• Use as one metric by NRC Reactor Oversight Program to evaluate ALARA program 

effectiveness and for inspection planning purposes. 

• Evaluate radiation exposure to transient individuals. 

• Use for establishing priorities for NRC health physics resources. 

• Provide facts for answering Congressional and administration inquiries and for answering 

public questions. 

 

38 NUREG-0713, Vol. 34; http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0713/v34/
23 

• Provide information that may be used to conduct epidemiologic studies. 

• Use in evaluating NRC radiation protection standards with respect to adopting the new ICRP 

103 recommendations”39. 

The NRC is able to address all of the foregoing purposes for those licensee categories for which 

NRC is the sole radiation safety regulatory authority (e.g., reactors, fuel cycle facilities, and 

radioactive waste disposal facilities). These licensee categories are already required to submit 

annual occupational exposure reports under 10 CFR 20.2206(a). However, NRC is not able to 

address all of these purposes for all material licensees, including medical and medically-related 

licensees, as noted in NUREG-0713, Vol. 34, Section 2 “Limitations of the Data”40. The term, 

“medically-related licensees,” used here refers to any material licensee providing 

radiopharmaceuticals, radiochemicals, radiation sources, and radiation services that medical 

licensees may use. The inclusion of additional categories of licensees required to submit annual 

occupational exposure reports to NRC is problematic as described in the answers below. 

Q6–2: What are the benefits of collecting occupational exposure information in one central 

database to assess the total annual occupational exposure of those individuals who work at more 

than one licensed facility or contractor facility during the calendar year and receive occupational 

exposures at these facilities?

A6–2: The NRC requires licensees to determine for each individual who is likely to receive an 

annual occupational dose requiring monitoring [10 CFR 20.1502] that individual’s occupational 

radiation dose received during the current year [10 CFR 20.2104] to document compliance with the 

NRC occupational dose limits [10 CFR 20 Subpart C]. The NRC may benefit from collecting 

annual occupational exposure information from more material licensees, including medical and 

medically-related licensees, in its evaluation of radiation exposure for transient workers, and 

perhaps in its evaluation of Agreement States radiation control programs. But as NRC states in 

NUREG-0713, Vol. 3441, Section 2, “The average dose per individual, as well as the dose 

distributions shown for groups of licensees, also can be affected by the multiple reporting of 

individuals who were monitored by two or more licensees during the year.” 

The NRC defines occupational dose as [10 CRF 20.1003]: 

“Occupational dose means the dose received by an individual in the course of employment 

in which the individual's assigned duties involve exposure to radiation or to radioactive 

material from licensed and unlicensed sources of radiation, whether in the possession of the 

licensee or other person. Occupational dose does not include doses received from 

background radiation, from any medical administration the individual has received, from 

exposure to individuals administered radioactive material and released under § 35.75, from 

voluntary participation in medical research programs, or as a member of the public.” 

 

39 2007 Recommendations of the International Commission on Radiological Protection". Annals of the ICRP. ICRP 

publication 103 37 (2-4), 2007. 

40 NUREG-0713, Vol. 34; http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0713/v34/
24 

Some material licensees, such as medical and medically-related licensees, will have individuals 

whose occupational exposure includes exposure to unlicensed sources of ionizing radiation (e.g., xray machines, accelerators, non-byproduct materials nor regulated by the NRC, etc.). If the purpose 

of a central database is to assess total annual occupational exposures for radiation workers, the 

NRC’s limited regulatory authority would not make it the ideal federal entity to manage such a 

central database. 

Q6–3: Should Agreement States be required to adopt regulations that are compatible with the 

requirements in 10 CFR 20.2206? 

A6–3: No. This question is equivalent to asking whether NRC should manage a central database 

collecting occupational exposure data. As noted in the NRC’s Issue Paper 6, “Reporting of 

Occupational Exposure” (http://pbadupws.nrc.gov/docs/ML1408/ML14084A344.pdf), “More than 

seven times as many radioactive material licensees are regulated by Agreement States than those 

regulated by the NRC.” The NRC and Agreement States regulatory authority comes from the 

Atomic Energy Act (AEA) of 1954, as Amended 

(http://pbadupws.nrc.gov/docs/ML1327/ML13274A489.pdf#page=23). The Occupational Safety & 

Health Administration (OSHA) and each State are regulatory authorities for occupational exposure 

to non-AEA radiation sources. The split of these regulatory authorities are summarized in this 

table. There are additional Federal and State entities that may not fall under these regulatory 

authorities in regard to occupational exposure to radiation. 

Regulatory Authority for Occupational Exposure to Radiation

Regulator 

Reactors/Fuel 

Cycle/Radioactive 

Waste Disposal 

Radioactive 

Materials under 

AEAa

Radiation-Producing 

Machines/Non-AEA 

Radioactive Materials 

Nuclear Regulatory 

Commission (NRC) 100 % 12.5 % 0 % 

Stateb 0 % 87.5 %c

 100 %e

Occupational Safety 

& Health Administration (OSHA) 

0 % 0 %d

 100 %e

a

 Atomic Energy Act of 1954, as Amended 

b

 State can be one of the 50 States or a U.S. Territory c

 State is required to be one of the 37 Agreement States d

 As per OSHA regulation 29 CFR 1910.1096(p) and per Memorandum of Understanding between NRC and OSHA 

(http://pbadupws.nrc.gov/docs/ML1135/ML11354A432.pdf) e

 As per OSHA Instruction STD 01-04-001 

(https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=DIRECTIVES&p_id=1771)

NOTE: The NRC and OSHA do not have regulatory authority over certain other Federal and State 

entities. 
25 

Given the current division of regulatory authority, any consideration of establishing a central 

database for occupational exposure to radiation should address this division before requiring 

Agreement States to adopt regulations that are compatible with the requirements in 10 CFR 

20.2206. 

Q6–4: Should the NRC consider a gradual expansion of the 10 CFR 20.2206 licensee reporting 

categories in a step-wise fashion (e.g., staggered compliance dates for different categories of 

licensees)? What are the advantages or disadvantages for this option? 

A6–4: No, as noted in the previous answers. 

Q6–5: What are the potential implementation and operational costs associated with expanding the 

occupational exposure reporting requirements? 

A6–5: The regulatory authority issue noted in A6–3 needs to be addressed before investing in 

expansion of the NRC’s occupational exposure reporting requirements. If expansion of this 

reporting was deemed worthwhile for only AEA-regulated activities, the listing of 99 license 

categories (41 license categories for medical and medically-related licensees) provides an indicator 

of the number of licensees potentially impacted. 

 
26 

ABREVIATIONS

ACL – administrative control level 

ACMUI – Advisory Committee on the Medical Uses of Isotopes 

ACRS – Advisory Committee on Reactor Safeguards 

AEA – Atomic Energy Act 

ALARA – as low as reasonably achievable 

ALI – annual limit on intake 

ANPR – Advanced Notice of Proposed Rulemaking 

BEIR – Biological Effects of Ionizing Radiation, a series of reports by the Committee to Assess 

Health Risks from Exposure to Low Levels of Ionizing Radiation, Board on Radiation 

Effects Research, Division on Earth and Life Studies, National Research Council of the 

National Academies

CFR – Code of Federal Regulation 

CMS – Centers for Medicare & Medicaid Services 

DAC – derived air concentration 

DCF – dose conversion factor 

EAR – excess absolute rate 

EDE – effective dose equivalent 

FR – Federal Register 

Gy – gray 

HAT – human alimentary tract 

HPS – Health Physics Society 

ICRP – International Commission on Radiological Protection 

LET – linear energy transfer 

mCi – millicurie 

mL – milliliter 

mm – millimeter 

mSv – millisievert 

NCRP – National Council on Radiation Protection and Measurements 

NRC – Nuclear Regulatory Commission 

OSHA – Occupational Safety & Health Administration 

PET – positron emission tomography 

QA – quality assurance 

QF – quality factor 

RERF – Radiation Effects Research Foundation 

SI – International System of Units 

Sv – sievert 

TEDE – Total effective dose equivalent 

U.S. – United States 

90Y – yttrium-90