[Federal Register Volume 76, Number 168 (Tuesday, August 30, 2011)]
[Proposed Rules]
[Pages 53847-53851]
From the Federal Register Online via the Government Publishing 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 http://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: [email protected].
Mail comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and
Adjudications Staff.
E-mail comments to: [email protected]. 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: [email protected], or Dr. Donald Cool, telephone:
301-415-6347, e-mail: [email protected], 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 http://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 http://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 [email protected].
Federal rulemaking Web site: Public comments and
supporting materials related to this proposed rule can be found at
http://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 http://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
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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 (http://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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