New International Commission on Radiological Protection; Recommendations on the Annual Dose Limit to the Lens of the Eye, 53847-53851 [2011-21900]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 76, Number 168 (Tuesday, August 30, 2011)]
[Proposed Rules]
[Pages 53847-53851]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-21900]


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NUCLEAR REGULATORY COMMISSION

10 CFR Chapter I

[NRC-2009-0279]


New International Commission on Radiological Protection; 
Recommendations on the Annual Dose Limit to the Lens of the Eye

AGENCY: Nuclear Regulatory Commission.

ACTION: Request for public comment.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC or the Commission) 
is continuing its stakeholder outreach of possible changes to the 
radiation protection standards by seeking public comment on the newly 
released International Commission on Radiological Protection (ICRP) 
recommendations for the limitation of annual dose to the lens of the 
eye. This significant new recommendation has not yet been the subject 
of any stakeholder or public interactions on any potential changes to 
the NRC's radiation protection regulations. The NRC has not initiated 
rulemaking on this subject, and is seeking early input and views on the 
benefits and impacts of options to be considered before making any 
decision on whether to consider this issue for future rulemaking. 
Stakeholders and the public are encouraged to submit comments

[[Page 53848]]

concerning potential impacts, burdens, benefits, and concerns on the 
issues discussed in this notice.

DATES: Submit comments by October 31, 2011. Comments received after 
this date will be considered if it is practical to do so, but the NRC 
is able to assure consideration only for comments received on or before 
this date.

ADDRESSES: Please include Docket ID NRC-2009-0279 in the subject line 
of your comments. For instructions on submitting comments and accessing 
documents related to this action, see Section I, ``Submitting Comments 
and Accessing Information'' in the SUPPLEMENTARY INFORMATION section of 
this document. Members of the public are invited and encouraged to 
submit comments by any of the following methods:
     Federal rulemaking Web site: Go to https://www.regulations.gov and search for documents filed under Docket ID NRC-
2009-0279. Address questions about NRC dockets to Carol Gallagher; 
telephone: 301-492-3668; e-mail: Carol.Gallagher@nrc.gov.
     Mail comments to: Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and 
Adjudications Staff.
     E-mail comments to: Rulemaking.Comments@nrc.gov. If you do 
not receive a reply e-mail confirming that we have received your 
comments, contact us directly at 301-415-1677.
     Hand deliver comments to: 11555 Rockville Pike, Rockville, 
Maryland 20852, between 7:30 a.m. and 4:15 p.m. on Federal workdays. 
Telephone: 301-415-1677.
     Fax comments to: Secretary, U.S. Nuclear Regulatory 
Commission at 301-415-1101.

FOR FURTHER INFORMATION CONTACT: Solomon Sahle, telephone: 301-415-
3781, e-mail: Solomon.Sahle@nrc.gov, or Dr. Donald Cool, telephone: 
301-415-6347, e-mail: Donald.Cool@nrc.gov, of the Office of Federal and 
State Materials and Environmental Management Programs, U.S. Nuclear 
Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

I. Submitting Comments and Accessing Information

    Comments submitted in writing or in electronic form will be posted 
on the NRC Web site and on the Federal rulemaking Web site https://www.regulations.gov. Because your comments will not be edited to remove 
any identifying or contact information, the NRC cautions you against 
including any information in your submission that you do not want to be 
publicly disclosed. The NRC requests that any party soliciting or 
aggregating comments received from other persons for submission to the 
NRC inform those persons that the NRC will not edit their comments to 
remove any identifying or contact information, and therefore, they 
should not include any information in their comments that they do not 
want publicly disclosed.
    You can access publicly available documents related to this notice 
using the following methods:
     NRC's Public Document Room (PDR): The public may examine 
and have copied, for a fee, publicly available documents at the NRC's 
PDR, O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, 
Maryland 20852.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): Publicly available documents created or received at the NRC 
are available online in the NRC Library at https://www.nrc.gov/reading-rm/adams.html. From this page, the public can gain entry into ADAMS, 
which provides text and image files of the NRC's public documents. If 
you do not have access to ADAMS or if there are problems in accessing 
the documents located in ADAMS, contact the NRC's PDR reference staff 
at 1-800-397-4209, 301-415-4737, or by e-mail to pdr.resource@nrc.gov.
     Federal rulemaking Web site: Public comments and 
supporting materials related to this proposed rule can be found at 
https://www.regulations.gov by searching on Docket ID NRC-2009-0279.

II. Background

    Regulations issued by the NRC are found in Chapter I of Title 10, 
``Energy,'' of the Code of Federal Regulations (10 CFR). Chapter I is 
divided into Parts 1 through 199, and contains requirements that are 
binding for all individuals and entities that possess, use, or store 
nuclear materials or operate nuclear facilities under the NRC's 
jurisdiction. Of these, the regulations that are most relevant to the 
subject of this notice are contained in 10 CFR part 20, ``Standards for 
Protection against Radiation.'' Through the existing compatibility 
criteria, the NRC Agreement States have certain requirements that are 
essentially identical to those contained in 10 CFR part 20 for their 
licensees. Additional requirements, specific to particular uses or 
classes of facilities, are found in other portions of the NRC's 
regulations. For example, 10 CFR part 35, ``Medical Use of Byproduct 
Material,'' contains requirements related to the medical use of 
radioactive material, and 10 CFR part 50, ``Domestic Licensing of 
Production and Utilization Facilities,'' contains additional 
requirements for power reactors. Other portions of the NRC's 
regulations also may contain radiation protection criteria, and cross 
references to 10 CFR part 20.
    The ICRP Publication 103 (December 2007) contains the latest in a 
series of revised ICRP recommendations for radiation protection. On 
December 18, 2008, the NRC staff provided a Policy Issue Notation Vote 
Paper (SECY-08-0197; ADAMS Accession No. ML083360582) to the 
Commission, which presented the regulatory options of moving, or not 
moving, towards a greater degree of alignment of the NRC regulatory 
framework with ICRP Publication 103. In a Staff Requirements Memorandum 
(SRM) dated April 2, 2009 (ADAMS Accession No. ML090920103), the 
Commission approved the staff's recommendation to begin engaging with 
stakeholders and interested parties to initiate development of the 
technical basis for possible revision of the NRC's radiation protection 
regulations, as appropriate and where scientifically justified, to 
achieve greater alignment with the recommendations in ICRP Publication 
103.
    This notice of solicitation of comment represents the third in a 
series of such requests. Previous notices were published in the Federal 
Register on July 7, 2009 (74 FR 32198), and September 27, 2010 (75 FR 
59160). In addition, the NRC staff held a series of facilitated public 
workshops in October and November 2010, to engage the views of a wide 
range of stakeholders on the key issues presented by the ICRP 
recommendations.
    On April 21, 2011, the ICRP issued a statement on tissue reactions 
(see https://www.icrp.org/docs/ICRP%20Statement%20on%20Tissue%20Reactions.pdf) stating that it has 
reviewed recent epidemiological evidence suggesting that there are some 
tissue reaction effects, particularly those with very late 
manifestation, where threshold doses are or might be lower than 
previously considered. For the lens of the eye, the threshold in 
absorbed dose for radiation-induced cataract formation is now 
considered by the ICRP to be 0.50 Gy (50 rem). Consequently, for 
occupational exposure in planned exposure situations, the ICRP is now 
recommending a limit on equivalent dose for the lens of the eye of 20 
mSv (2 rem) per year, averaged over defined periods of 5 years, with no 
single year exceeding 50 mSv (5 rem). The ICRP's recommended limits for 
dose for the

[[Page 53849]]

lens of the eye are numerically equal to its current recommendation for 
the limit on effective dose, which is 20 mSv (2 rem) per year, averaged 
over 5 years, with no single year exceeding 50 mSv (5 rem).
    The supporting information reviewed by the ICRP was provided for 
public consultation in December 2010 (https://www.icrp.org/docs/Tissue%20Reactions%20Report%20Draft%20for%20Consultation.pdf). This 
draft report will be revised in light of the comments received by the 
ICRP during the public consultation period, and is expected to become a 
final ICRP report towards the end of 2011.
    The international radiation protection community is currently 
examining the issue of revising the dose limits for the lens of the 
eye. In particular, the International Atomic Energy Agency has 
specifically considered and is now incorporating, the new limits into 
the revision of the International Basic Safety Standards for Protection 
against Ionizing Radiation and for the Safety of Radiation Sources.
    Protection of the eye against the effects of ionizing radiation is 
designed primarily to prevent the formation of cataracts. The sensitive 
part of the eye for this health effect is the lens, and radiation dose 
to the eye is defined as the lens dose equivalent (LDE) at a tissue 
depth of 0.3 cm (10 CFR 20.1003). Cataract formation falls under the 
class of radiation effects referred to as deterministic (or tissue 
reactions in current ICRP terminology). At doses above the threshold, 
the severity of cataract formation increases with dose, but the 
radiation-induced incidence below the threshold dose is believed to be 
essentially zero. Currently, 10 CFR part 20 limits annual occupational 
exposures to the lens of the eye to 150 mSv (15 rem) per year (10 CFR 
20.1201).
    The NRC is supplementing its standard rulemaking process by 
conducting enhanced public participatory activities before the 
initiation of any formal rulemaking process, to solicit early and 
active public input on major issues associated with radiation 
protection regulations. As a first step, the NRC has prepared an issues 
paper that describes issues and alternatives related to limits for the 
lens of the eye. The intent of this paper is to foster discussion about 
these issues and alternatives before a rulemaking to set standards 
would begin. The content of the issues paper is contained in Section IV 
of this document. The NRC will also utilize its rulemaking Web site to 
make the issues paper available to the public and to solicit public 
comments.

III. Request for Written and Electronic Comments

    The NRC is soliciting comments on the items presented in the issues 
paper in Section IV of this notice. Comments may be submitted either in 
writing or electronically as indicated in the ADDRESSES section of this 
document.
    In addition to inviting public comments on the issues presented in 
Section IV, the NRC is soliciting specific comments related to: (1) 
Quantitative and qualitative information on the costs and benefits 
resulting from consideration of the factors described in the issues 
paper; (2) operational data on radiation exposures and administrative 
control methods that might result in increased or reduced exposures 
when implementing the associated change in a dose limit; (3) whether 
the presented factors are appropriate; and (4) whether other factors 
should be identified and considered, including providing quantitative 
and qualitative information for these factors. The Commission believes 
that the stakeholders' comments will help to quantify the potential 
impact of these changes and will assist the NRC, as it continues to 
consider alternatives for the radiation protection framework.
    The NRC does not plan to provide specific responses to the comments 
received during this solicitation. Based on the comments received, the 
NRC staff will prepare policy issues for Commission consideration on 
whether to proceed with the development of a proposed rule or take 
other regulatory action. If the Commission decides to proceed further 
with a proposed rulemaking, any proposed rule will be published in the 
Federal Register for public review and comment.

IV. Issues Paper on the Dose Limit to the Lens of the Eye

Introduction

    On April 21, 2011, the ICRP issued a statement on tissue reactions, 
indicating that it has now reviewed recent epidemiological evidence 
suggesting that there are some tissue reaction effects, particularly 
those with very late manifestation, where threshold doses are or might 
be lower than previously considered. For the lens of the eye, the 
threshold in absorbed dose for radiation-induced cataract formation is 
now considered to be 0.5 Gy (50 rem). Consequently, for occupational 
exposure in planned exposure situations, the ICRP is now recommending a 
limit on equivalent dose for the lens of the eye of 20 mSv (2 rem) per 
year, averaged over defined periods of 5 years, with no single year 
exceeding 50 mSv (5 rem).

Issues and Options

    To understand the magnitude of the doses incurred by the lens of 
the eye in the various industries regulated by the NRC, the NRC staff 
initially queried the Radiation Exposure Information and Reporting 
System (REIRS) database for occupational dose records over the past 16 
years (1994-2010). Under 10 CFR 20.2206, seven NRC-licensed industry 
groups must report occupational radiation exposure data. These licensed 
industries are commercial nuclear power reactors; industrial 
radiographers; fuel processors (including uranium enrichment 
facilities), fabricators, and reprocessors; manufacturers and 
distributors of byproduct material; independent spent fuel storage 
installations; facilities for land disposal of low-level waste; and 
geological repositories for high-level waste. Currently, there are no 
NRC-licensed facilities for land disposal of low-level waste or 
geological repositories for high-level waste. Therefore, these licensee 
categories do not submit occupational radiation exposure reports to the 
REIRS database. Other categories of NRC licensees (e.g., medical 
licensees) are not currently required to submit reports of occupational 
exposure. While Agreement State licensees are not required to provide 
reports to the NRC, some licensees within the industrial radiography 
and nuclear pharmacy categories have voluntarily submitted occupational 
radiation exposure reports to the REIRS database.
    Annually, the NRC receives approximately 200,000 occupational 
radiation exposure reports to the REIRS database (NUREG-0713, 
``Occupational Radiation Exposure at Commercial Nuclear Power Reactors 
and Other Facilities'' (ADAMS Accession No. ML110820543). The reports 
are generally submitted electronically as an NRC Form 5 record of 
occupational exposure for a monitoring period. The form includes fields 
to report deep dose equivalent (DDE), lens dose equivalent (LDE), 
committed effective dose equivalent (CEDE), total effective dose 
equivalent (TEDE), and shallow dose equivalent (SDE). For the purpose 
of this overview, the staff assumes that the reported DDE and LDE are 
taken from the same measurement, and that there is relatively 
infrequent direct measurement of LDE within the 200,000 records 
submitted annually.
    In terms of the new ICRP recommendations for the lens of the eye, 
the staff focused on REIRS data for the

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past 5 years (2006-2010) and found that current practices have resulted 
in upwards of 1,000 cases where a 20 mSv (2 rem) per year eye dose 
level was exceeded. None of these situations exceeded the current 
annual limit for the lens of the eye of 150 mSv (15 rem). The initial 
examination of REIRS data did not determine whether the same individual 
exceeded a 2 rem per year average over the 5-year period. The REIRS 
database did not contain a record where the deep dose equivalent 
exceeded a value of 50 mSv (5 rem) in a single year.
    It can be concluded, based on this preliminary analysis, that 
current radiation protection practices would result in a considerable 
number of instances where dose to the lens of the eye exceeds 20 mSv (2 
rem) per year. It should be noted that the reported TEDE and LDE 
values, above 20 mSv (2 rem) per year, are not necessarily associated 
with the same individuals each year. To obtain data on accumulated DDE 
for individuals, the NRC staff initially analyzed data for the past 16 
years and found that no individual in any of the NRC-licensed 
industries reporting to REIRS, including individuals in those 
categories as reported by Agreement State licensees, has exceeded a 
cumulative exposure of 0.5 Sv (50 rem) during this period (1994-2010).
    The information available to the NRC staff indicates that the 
majority of NRC-regulated workers are usually exposed to fairly uniform 
radiation fields. In this exposure environment, and without the use of 
shielding for portions of the body, the equivalent dose to the lens of 
the eye is typically similar to the TEDE. Therefore, measures to 
minimize radiation exposure, in general, will also result in a 
reduction in dose to the lens of the eye. Likewise, in many instances, 
an annual whole body dose that exceeds an annual level of 20 mSv (2 
rem) would likely mean that the lens dose would also exceed 20 mSv (2 
rem).
    There are other types of licensed uses for which reporting of dose 
is not currently a requirement. For example, the NRC staff has been 
made aware of possible eye dose issues associated with licensees using 
depleted uranium in the fabrication of shielding, counterweights, etc. 
Further, some types of exposure, such as to machine-produced radiations 
(e.g., x-rays), are not the subject of NRC jurisdiction, and thus 
exposures in these categories are not reported to the NRC. However, the 
occupational dose to individuals exposed to both NRC-licensed 
radioactive materials, as well as non-NRC-licensed sources (e.g., x-
rays), is regulated to the 10 CFR part 20 dose limits. Exposures to the 
lens of the eye may be particularly important in some of these fields, 
and others, such as medical interventional radiology and cardiology, 
which are subject to regulation by the States, but are not necessarily 
under NRC jurisdiction.
    In situations where there may be a non-uniform radiation field, or 
where shielding reduces the exposure to significant portions of the 
body, the dose to the lens of the eye might be greater than the TEDE. 
In such circumstances, specific additional protection measures might be 
necessary to reduce exposure to the lens of the eye. The NRC staff 
understands that the use of leaded safety glasses has proven effective 
in significantly reducing dose to the lens of the eye from soft x-rays, 
and use of such glasses with side shields is effective in situations 
where there is significant scatter of low energy radiation, such as in 
interventional radiology and cardiology, where shielding is already 
provided for the torso to reduce the effective dose. The use of leaded 
safety glasses might not be effective for use by industrial 
radiographers, where the greater energies of the radiation make it 
difficult or impractical to provide significant shielding to the lens 
of the eye.
    In considering possible changes, the NRC staff must consider the 
implications of the dose limits for the lens of the eye in connection 
with all of the other issues that have been previously discussed with 
stakeholders, including the implications of a change to the dose limit 
for TEDE, and the implications of strengthening or modifying the 
requirements for optimization analysis using planning values to ensure 
that exposures are As Low As Is Reasonably Achievable.
    As in all regulatory proceedings, the NRC could pursue several 
possible options. The NRC staff has identified the following three 
options for initial consideration and assessment in considering a 
revision to associated regulations and regulatory guidance.
    1. No change: Continue with the existing regulatory requirement to 
limit dose to the lens of the eye to 150 mSv (15 rem) per year.
    2. Change the current requirements by adopting the ICRP- 
recommended dose values.
    3. Change the current requirements to adopt a single, reduced dose 
limit for the lens of the eye. For example, a single limit of 50 mSv (5 
rem) or 20 mSv (2 rem).

Questions

    The NRC staff is seeking stakeholder input on the issues, 
implications, and options relating to possible changes to the NRC 
regulatory requirements to reflect the ICRP's recommendations for 
lowering the dose limit for the lens of the eye. The NRC is soliciting 
specific comments related to: (1) Quantitative and qualitative 
information on the costs and benefits resulting from consideration of 
the factors described in this issues paper, (2) operational data on 
radiation exposures and administrative control methods that might 
result in increased or reduced exposures in implementing the associated 
changes in a dose limit; (3) whether the presented factors are 
appropriate; and (4) whether other factors should be identified and 
considered, including providing quantitative and qualitative 
information for these factors. The following questions identify areas 
in which the NRC staff is seeking specific views and inputs. However, 
stakeholders are invited to identify and address other areas and 
implications not specifically mentioned here or in the issues paper.
    1. To what extent has dose to the lens of the eye been an issue in 
the implementation of your radiation protection program, and would a 
change in the limits cause operational and administrative impacts? What 
other types of impacts would you foresee?
    2. What types of specific administrative and monitoring methods 
would be available in your use of radiation or radioactive materials to 
reduce exposures to the lens of the eye, and what would be the costs 
and operational impacts of implementing such methods?
    3. What might be the anticipated impacts of a rule change on 
recordkeeping and reporting?
    4. Are there technological implementation issues, such as limits of 
detection as compared to currently used radiation monitoring methods, 
or availability of dosimetry, that would make adoption of the ICRP 
recommendations difficult or impractical in certain circumstances? If 
possible, please provide a typical example of such a circumstance.
    5. How does the recommended limit to the lens of the eye influence 
your views on possible changes to the limits on TEDE, given that these 
two quantities are expected to be essentially the same for many 
exposure situations?
    6. What alternatives to adoption of the new limits would you 
suggest in achieving the desired outcome of limiting exposure of the 
lens of the eye over the working lifetime of an employee?
    7. What should be the relationship between the U.S. regulatory 
requirements and those adopted

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internationally? What impacts, either positive or negative, would 
result from an alignment of NRC regulatory requirements and guidance 
with international standards?
    8. Should licensees be required to monitor and report LDE for 
foreign workers and report the values upon request? Are there other 
impacts (e.g., operational, administrative, costs, etc.) that should be 
anticipated if the U.S. regulatory structure were to be different from 
that being used in other countries?
    9. Are there any other NRC regulations and regulatory guidance that 
might need to be reviewed and revised as a result of ICRP 
recommendations in reducing the allowable dose to the lens of the eye?
    10. How are licensees monitoring to demonstrate compliance with the 
existing dose limits for the lens of the eye?

    Dated at Rockville, Maryland, this 19th day of August 2011.

    For the Nuclear Regulatory Commission.
Josephine M. Piccone,
Director, Division of Intergovernmental Liaison and Rulemaking, Office 
of Federal and State Materials and Environmental Management Programs.
[FR Doc. 2011-21900 Filed 8-29-11; 8:45 am]
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