[Federal Register Volume 60, Number 55 (Wednesday, March 22, 1995)]
[Proposed Rules]
[Pages 15180-15190]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-6872]
[[Page 15179]]
_______________________________________________________________________
Part II
Nuclear Regulatory Commission
_______________________________________________________________________
10 CFR Part 60
Disposal of High-Level Radioactive Wastes in Geologic Repositories;
Proposed Rules
Federal Register / Vol. 60, No. 55 / Wednesday, March 22, 1995
/ Proposed Rules
[[Page 15180]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 60
RIN 3150-AD51
Disposal of High-Level Radioactive Wastes in Geologic
Repositories; Design Basis Events
AGENCY: Nuclear Regulatory Commission.
ACTION: Proposed rule.
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SUMMARY: The Nuclear Regulatory Commission is proposing to amend its
policy on the protection of public health and safety from activities
conducted at a geologic repository operations area (GROA) before
permanent closure. In particular, the proposed rule would address the
measures that are required to provide defense in depth against the
consequences of ``design basis events.'' These measures include
prescribed design requirements, quality assurance requirements, and the
establishment of a preclosure controlled area from which members of the
public can be excluded.
DATES: Comments must be submitted on or before June 20, 1995. Comments
received after this date will be considered if it is practical to do
so, but the Commission is able to ensure consideration only for
comments received on or before this date.
ADDRESSES: Send comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001. Attention: Docketing and Service
Branch.
Hand-deliver comments to: 11555 Rockville Pike, Rockville,
Maryland, between 7:45 am and 4:15 pm Federal workdays.
Examine comments received at the NRC Public Document Room, 2120 L
Street NW (Lower Level), Washington, DC.
FOR FURTHER INFORMATION CONTACT: Dr. Richard A. Weller, Division of
Waste Management, Office of Nuclear Material Safety and Safeguards,
U.S. Nuclear Regulatory Commission, Washington, DC 20555, telephone
(301) 415-7287.
SUPPLEMENTARY INFORMATION:
Background
Under the Nuclear Waste Policy Act of 1982, as amended, the U.S.
Nuclear Regulatory Commission exercises licensing and related
regulatory authority with respect to geologic repositories that are to
be constructed and operated by the U.S. Department of Energy (DOE) for
the disposal of high-level radioactive waste. The Commission's
regulations pertaining to these geologic repositories appear at 10 CFR
part 60. In recent years, NRC, in conjunction with its Federally-Funded
Research and Development Center (the Center for Nuclear Waste
Regulatory Analyses), completed a comprehensive review of the
requirements of part 60, regarding their clarity and sufficiency to
protect public health and safety. NRC focused particular attention on
any matters that may be ambiguous, insufficient for their intended
purpose, or inconsistent with other expressions of its regulatory
policy. The amendments presented in this proposed rule deal with a
matter that was brought to light by this review and by a petition for
rulemaking (PRM) filed by DOE (PRM-60-3).
The issue concerns the protection of public health and safety for a
broad range of normal and accident conditions during the operational
period of a geologic repository (i.e., before permanent closure). The
Commission is concerned that the current requirements of part 60 may be
unclear and may be insufficient to protect public health and safety for
the full range of credible conditions or events that may occur at an
operating repository, including those low-probability events that have
potentially serious consequences. The Commission also notes that
certain elements of existing part 60 differ from counterpart
requirements in other NRC rules, and it believes that greater
consistency in language would be beneficial. NRC is proposing
rulemaking to address these identified concerns. To develop and explain
the changes to the regulatory requirements that appear to be desirable,
it would be useful to review the pertinent provisions of existing part
60. In this review and in subsequent discussions in this notice, unless
the specific context suggests otherwise, the terms ``provisions,''
``requirements,'' ``standards,'' and ``criteria'' are generally used
interchangeably; the term ``limit'' (as in ``dose limit'') is generally
used to refer to a specific type of requirement or criterion; and the
term ``rule'' is generally used to refer to the entire set of
requirements or criteria (e.g., part 60).
The Existing Rule
The provisions of part 60 generally reflect the defense-in-depth
philosophy of the Commission that is commonly embodied in the
requirements and practices for other types of Commission-regulated
facilities, such as commercial nuclear power reactors and independent
spent fuel storage installations (ISFSIs), with the overall intent to
prevent or mitigate the occurrence of serious accidents and, thereby,
to protect the public health and safety. Defense-in-depth is provided
for, during the preclosure period, by conservatism, redundancy, and
diversity in design; the application of a comprehensive quality
assurance program, to facility design, construction, operation, and
maintenance; the imposition of radiation protection standards, for both
workers and members of the public, to limit the potential adverse
consequences of licensed activities to levels that are well within the
bounds of risks accepted in other productive activities in society; and
requirements for radiation safety programs and procedures and emergency
plans. The Commission's radiation protection standards are codified in
10 CFR part 20.
Specifically, defense-in-depth is implemented in Part 60 by
repository performance objectives and by detailed siting and design
criteria. Further, the rule provides that those structures, systems,
and components determined to be ``important to safety'' would be
subject to additional design requirements and to quality assurance
requirements, to add confidence that the repository and its subsystems
will perform satisfactorily in service. However, examination of the
specific provisions of the rule indicates that some elements may be
deficient in terms of their clarity, sufficiency, or consistency with
other NRC rules, resulting in concerns about the adequacy of defense-
in-depth in Part 60. The most significant concerns relate to: (1) The
definition of structures, systems, and components ``important to
safety'' and the ability to identify such features; (2) uncertainties
in the performance objective for radiation protection; and (3) the lack
of consistency with 10 CFR part 72 (``Licensing Requirements for the
Independent Storage of Spent Nuclear Fuel and High-Level Radioactive
Waste'') which applies to ``monitored retrievable storage (MRS)
installations,'' the facilities most similar to a repository, during
the repository's operational period. These concerns are discussed in
turn.
``Important-to-Safety'' Definition
The regulation states (10 CFR 60.2):
``Important to safety,'' with reference to structures, systems,
and components means those engineered structures, systems, and
components essential to the prevention or mitigation of an accident
that could result in a radiation dose to the whole body, or any
organ, of 0.5 rem or greater at or beyond the nearest boundary of
the unrestricted area at any time until the completion of permanent
closure.
[[Page 15181]] Note, first, that the definition refers to
repository features ``essential to the prevention or mitigation of an
accident'' (emphasis added) in the context of a dose limit (0.5 rem)
``* * * equal to the annual dose to the whole body of an individual in
an unrestricted area that would be permitted under 10 CFR Part 20 for
normal operations * * *'' (48 FR 28202; June 21, 1983, Final rule,
``Disposal of High-Level Radioactive Wastes in Geologic
Repositories''). However, the definition is unclear with respect to the
range of ``accidents'' to be considered when it is applied to identify
those structures, systems, and components important to safety. As such,
the uncertainty in the definition raises questions about the adequacy
of the requirements, in the rule, to protect the public health and
safety for the full range of conditions or events that may occur before
closure, including those credible, but unlikely events with potentially
significant radiological consequences. Second, the focus of the
definition is the protection of members of the public in unrestricted
areas and, although supplemental design and quality assurance
requirements for this purpose may also indirectly benefit onsite
workers for some conditions or events, the definition does not
explicitly address protection for the occupational workforce. Lastly,
the value of 5 mSv (0.5 rem) as a dose limit in unrestricted areas for
``accident'' conditions is peculiar to part 60, and lacks consistency
with a corresponding limit in 10 CFR part 72.
Performance Objective for Radiation Protection
As stated previously, the Commission's numerical radiation
protection standards are codified in Part 20. These standards apply to
operations at a geologic repository by virtue of 10 CFR 20.1002 as well
as by 10 CFR 60.111(a), which provides, in part:
Protection against radiation exposures and releases of
radioactive material. The geologic repository operations area shall
be designed so that until permanent closure has been completed,
radiation exposures and radiation levels, and releases of
radioactive materials to unrestricted areas, will at all times be
maintained within the limits specified in Part 20 of this chapter *
* *.
There are two conceptual difficulties with this language and both
issues derive from the language in the rule that requires the limits of
part 20 to be met ``at all times.'' The first issue relates to the
uncertainty about the scope of activities intended in the requirement,
specifically, whether part 20 limits must be observed not only during
planned operations, but also if the emplaced waste has to be retrieved
in accordance with 10 CFR 60.111(b). The Commission previously
addressed this issue in a prior proposed rulemaking, explaining that
the phrase (``at all times'') was included in the regulation so as ``*
* * to emphasize the need to design the geologic repository operations
area so that any waste retrieval found to be necessary in the future
could be carried out in conformance with the radiation protection
requirements of 10 CFR Part 20'' (51 FR 22288; June 19, 1986, proposed
amendments to conform to U.S. Environmental Protection Agency (EPA)
general environmental standards). The Commission adheres to this
interpretation and believes that the application of part 20 limits to
possible retrieval activities is consistent with the policy followed in
the application of part 20 to corresponding activities (e.g., spent
fuel handling) at other facilities regulated by the Commission under 10
CFR parts 50 and 72 (i.e., at commercial power reactors and ISFSIs,
respectively).
The second issue relates to uncertainty about the scope of
conditions intended in Sec. 60.111(a), specifically, whether part 20
limits must be observed for the extreme conditions that may result from
credible, but unlikely, scenarios or events. Here, the Commission
recognizes the desirability of articulating its intentions more
clearly. For this purpose, it is helpful to use a simple classification
scheme for describing the broad range of conditions or events that
effectively provide the design basis for the facility. These so-called
``design basis events'' are defined as being of two categories:
(1) those natural and human-induced events that are reasonably
likely to occur regularly, moderately frequently, or one or more times
before permanent closure of the geologic repository operations area;
and
(2) other natural and human-induced events that are considered
unlikely, but sufficiently credible to warrant consideration, taking
into account the potential for significant radiological impacts on
public health and safety.
Category 1 events have typically been referred to in the rules and
guidance documents (e.g., regulatory guides) for Commission-regulated
facilities (nuclear power plants, MRS installations, geologic
repositories) as those conditions resulting from ``normal operation,
including anticipated operational occurrences.'' Anticipated
operational occurrences, including those of natural origin, are those
conditions expected to occur one or more times during the lifetime of
the facility.
In the administration of its regulatory program for facilities
licensed under parts 50 and 72, it has been the Commission's general
practice, as well as its intent in part 60, to apply the dose limits of
part 20 to Category 1 events. The Commission's intent, in this regard,
is further clarified in the statement of considerations related to
revision of its part 20 standards (56 FR 23360; May 21, 1991, Final
rule, ``Standards for Protection Against Radiation''). Here, the
Commission notes that the revision conforms its regulations to the
``Presidential Radiation Protection Guidance to Federal Agencies for
Occupational Exposure.'' The Commission further notes (56 FR 23365)
that the dose standards in the Presidential guidance only apply to
normal operating conditions. Although it is the Commission's intent
that the regulations in part 20 also be observed to the extent
practicable during emergencies, the Commission also recognizes that, in
an actual emergency, operations that do not conform to the regulations
may be necessary to protect public health and safety. Notwithstanding
the general applicability of these regulations to all operational
situations, it is not the Commission's intent that these requirements
apply to Category 2 events as a design basis for the facility.
Appropriate requirements other than the dose limits of part 20 would be
provided as the design basis for Category 2 events. Some of the
confusion about this matter is no doubt linked to the terminology used
in various Commission rules or guidance documents, where the terms
``accidents'' and ``anticipated operational occurrences'' may have been
used interchangeably. It should be recognized that some accidents''
may, indeed, be ``anticipated operational occurrences,'' if they are
expected to occur one or more times during the lifetime of the
facility. What is important, in this regard, is not the term applied to
the event, but its expected frequency of occurrence, to determine both
its category and whether part 20 limits should apply as a design basis.
Although the foregoing discussion may help to clarify the
Commission's intent regarding the applicability of part 20 limits to
Categories 1 and 2 design basis events, it leaves open the question
about the adequacy, to protect public health and safety, of the
requirements of part 60 for Category 2 events. The Commission now
proposes to address this matter by harmonizing the requirements of part
60, as appropriate, with other parts of its regulations--
[[Page 15182]] particularly art 72, which applies to facilities (MRS
installations) with much in common with repositories, during their
operational period. In this regard, the character and design of the
features of an MRS installation would be expected to be very similar to
the surface facilities of an operating repository. Further, the same
kind of functional activities would be performed at both types of
facilities, namely, receiving, handling, packaging, storing, and
retrieving high-level radioactive waste. As such, the Commission
believes that greater consistency between part 60 and part 72 is both
logical and desirable.
10 CFR Part 72
Part 72 also refers to structures, systems, and components
important to safety. However, instead of defining this concept in
specific quantitative terms, it provides the following (10 CFR 72.3):
``Structures, systems, and components important to safety'' mean
those features of the ISFSI (independent spent fuel storage
installation) or MRS (monitored retrievable storage installation)
whose function is:
(1) to maintain the conditions required to store spent fuel or
high-level radioactive waste safely;
(2) to prevent damage to the spent fuel or the high-level
radioactive waste container during handling and storage; or
(3) to provide reasonable assurance that spent fuel or high-
level radioactive waste can be received, handled, packaged, stored,
and retrieved without undue risk to the health and safety of the
public.
The Commission's concern in singling out this class of structures,
systems, and components is to identify those features that are so
important that it is prudent to warrant the application of special
design and quality assurance criteria. The design elements that are
then to be required are determined in the light of the design bases, a
term that is defined as follows:
``Design bases'' means that information that identifies the
specific functions to be performed by a structure, system, or
component of a facility and the specific values or ranges of values
chosen for controlling parameters as reference bounds for design.
These values may be restraints derived from generally accepted
``state-of-the-art'' practices for achieving functional goals or
requirements derived from analysis (based on calculation or
experiments) of the effects of a postulated event under which a
structure, system, or component must meet its functional goals. The
values for controlling parameters for external events include: (1)
estimates of severe natural events to be used for deriving design
bases that will be based on consideration of historical data on the
associated parameters, physical data, or analysis of upper limits of
the physical processes involved and (2) estimates of severe external
man-induced events to be used for deriving design bases that will be
based on analysis of human activity in the region taking into
account the site characteristics and the risks associated with the
event. (10 CFR 72.3.)
Part 72 provides for a quality assurance program that encompasses a
range of structures, systems, and components of somewhat indefinite
scope. According to 10 CFR 72.140(b), the program ``* * * must cover
the activities identified in 10 CFR 72.24(n),'' which in turn deals
with ``structures, systems, and components important to safety.'' The
application of these provisions relates to the qualitative language of
the definition of ``* * * structures, systems, and components important
to safety.'' In essence, an element is to be placed in this category if
its function is to provide reasonable assurance that there is no undue
risk to the health and safety of the public. Although the definition
lacks specific numerical guidance as to what constitutes ``undue
risk,'' the Commission, nevertheless, regards this as a stringent
test--one that contemplates that the numerical limits set out in part
20 will generally be met for Category 1 design basis events, consistent
with the general practice (as previously discussed) of the Commission
in the application of these standards.
With respect to Category 2 design basis events, numerical guidance
may be inferred from both the ``Siting Evaluation Factors'' (Subpart E)
and ``General Design Criteria'' (Subpart F) of part 72. As specified in
10 CFR 72.106, for each ISFSI or MRS facility, there must be a
``controlled area'' of such size that no individual located on or
beyond its boundary will receive a dose greater than 0.05 Sv (5 rem) to
the whole body, or to any organ, from any ``design basis accident.''
Both external natural events and external man-induced events must be
considered in defining the design bases that would result in the design
basis accident. 10 CFR 72.126(d) specifies that analyses must be made
to show that releases to the general environment from design basis
accidents will be within the exposure limits of 10 CFR 72.106. These
requirements suggest that the 0.05-Sv (5-rem) dose limit cited above
could be used to aid in the identification of structures, systems, and
components ``important to safety.'' However, although the existing
functional definition, in part 72, for ``important-to-safety''
features, has sufficed for identifying those corresponding components
or structures of an ISFSI, the Commission believes that the greater
specificity (i.e., numerical guidance) provided by a quantitative
definition similar in character to the existing part 60 definition
would be more suitable for the licensing of a more complex repository.
In the foregoing discussion, the Commission cited the requirements
of 10 CFR 72.106, which include provisions for the establishment of a
``controlled area'' boundary and dose criteria for limiting exposures
to individuals at or beyond that boundary, during design basis
accidents. The Commission notes that corresponding requirements are not
provided in part 60 which, in turn, raises questions about the adequacy
of the criteria in part 60 to ensure protection of public health and
safety.
There is another matter the Commission wishes to address, in this
action, that relates to another area of inconsistency between part 72
and part 60. Subpart F of part 72 provides the ``general design
criteria'' for an ISFSI or an MRS. These general design criteria
establish the minimum requirements for the design, fabrication,
construction, testing, maintenance, and performance, for the
structures, systems, and components of the facility that are important
to safety. In this regard, subpart F of part 72 is structured similarly
to, and performs the same function as, appendix A of 10 CFR part 50
(``General Design Criteria for Nuclear Power Plants'') in that both
sets of criteria establish minimum requirements for structures,
systems, and components ``important to safety.'' The corresponding
structure for the design criteria for the GROA in part 60 is somewhat
different from the corresponding structures in parts 72 and 50.
The design criteria for the GROA are provided in Secs. 60.130
through 60.134 and include criteria for both preclosure considerations
(i.e., criteria for features ``important to safety''), as well as
postclosure interests (i.e., criteria for features ``important to waste
isolation''). However, only the criteria of Sec. 60.131(b) are
identified as ``structures, systems, and components important to
safety,'' and it is unclear if other criteria specified in
Secs. 60.131(a), 60.132, and 60.133, for operational considerations,
are also ``important to safety.'' In this regard, the Commission notes
that there are some ``important-to-safety'' criteria in part 72 that
are not designated as such, in a corresponding manner, in part 60.
Although the Commission recognizes that this lack of consistency may be
due, in part, to the dual interests, in part 60, of preclosure safety
and postclosure isolation, the [[Page 15183]] Commission also believes
that this structure may contribute to the difficulty in determining
which features of the GROA are ``important to safety'' and subject to
the quality assurance provisions of subpart G.
The Petition for Rulemaking
On April 19, 1990, DOE filed a PRM with the Commission. It was
assigned Docket No. PRM-60-3. A notice of receipt was published in the
Federal Register on July 13, 1990 (55 FR 28771).
In its petition, DOE observed that 10 CFR 60.21(c)(3)(ii) requires
that the safety analysis report for a repository include a description
and analysis that considers ``* * *the adequacy of structures, systems,
and components provided for the prevention of accidents and mitigation
of the consequences of accidents, including those caused by natural
phenomena.'' Yet, part 60 does not provide numerical dose criteria
(i.e., dose limits) to use in identifying the need for engineered
safety features and for determining their adequacy.
DOE noted how similar operations at a geologic repository were to
those carried out at other licensed facilities, including, in
particular, facility operations for independent storage of spent
nuclear fuel. In common with these other facilities, the operations at
a repository would involve receipt, handling, transfer, and storage of
highly radioactive materials.
Under DOE's proposal, part 60 would be amended to include accident
dose limits of 0.05-Sv (5-rem) effective dose equivalent or 0.5-Sv (50-
rem) committed dose equivalent to any organ. These limits would apply
to any individual at the boundary of a newly defined ``preclosure
control area.'' The definition of the term ``important to safety''
would be revised, but would retain the 5-mSv (0.5-rem) dose limit;
however, unlike the present part 60, which relates this value to the
boundary of the unrestricted area, DOE's proposal would apply the dose
limit at the boundary of the preclosure control area. The phrase, ``at
all times,'' would be deleted from 10 CFR 60.111(a), to clarify that
part 20 does not apply to accident conditions. Lastly, DOE proposed
adding definitions of the terms ``preclosure control area,''
``committed dose equivalent,'' ``committed effective dose equivalent,''
and ``effective dose equivalent,'' to support the application of the
accident-dose limits described above.
For a fuller discussion of the PRM, see the July 13, 1990, Federal
Register notice.
Discussion
The Commission agrees with the petitioner that rulemaking is needed
to address the uncertainties related to appropriate accident-dose
limits for those unlikely, but credible, conditions or events (i.e.,
Category 2 design basis events) that might occur. In this regard, the
Commission agrees with the concept proposed by DOE, including the
application of appropriate accident-dose limits at the boundary of a
``preclosure control area.''
Regarding the current definition of ``important to safety,'' the
Commission agrees with DOE that the term should be revised so as to
clarify both its meaning and its intended scope. Although the revision
proposed by DOE captures the Commission's intent, with respect to
identifying those structures, systems, and components necessary to
prevent or mitigate the consequences of credible, but unlikely
accidents (i.e., Category 2 design basis events), it does not address
the Commission's parallel interest in those repository features
necessary to protect workers and members of the public from those
events that occur regularly, moderately frequently, or one or more
times during the lifetime of the GROA (i.e., Category 1 design basis
events). The Commission proposes to address this matter by both
expanding and modifying the current definition in part 60.
With regard to DOE's remaining major item of concern in its
petition, specifically the uncertainty in the language of 10 CFR
60.111(a), the Commission agrees with DOE's proposal to delete the
ambiguous phrase ``at all times'' from the rule, to clarify that the
objective does not apply to radiation exposures, levels, or releases
from those credible, but unlikely conditions or events that are
referred to above as Category 2 design basis events. Notwithstanding
this change, it remains the Commission's intent that this performance
objective applies to all functional activities (e.g., radioactive waste
receiving, handling, packaging, storage, and emplacement) expected to
occur at a repository site, including retrieval, if that becomes
necessary.
Finally, with respect to the new definitions that DOE proposed for
10 CFR 60.2, the Commission agrees that there is a need to define a
boundary for a ``preclosure control area.'' However, the terms
``committed dose equivalent,'' ``committed effective dose equivalent,''
and ``effective dose equivalent'' are all defined terms, in part 20,
and incorporated into part 60 by virtue of 10 CFR 60.111(a). As such,
these terms do not need to be defined in part 60.
Based on the foregoing discussion of DOE's petition and the
interest of greater consistency between part 60 and part 72, as
previously discussed, the Commission proposes to amend part 60 to
ensure the adequacy of its requirements to protect the public health
and safety. In this regard, dose limits are proposed, in the rule, for
protection of members of the public, during Category 1 and Category 2
design basis events, and for protection of workers, during Category 1
design basis events. The Commission notes that dose limits are not
proposed for protection of workers during Category 2 design basis
events, consistent with the policy in practice for facilities regulated
by the Commission under parts 50 and 72.
The Commission has determined that specific standards for the
protection of workers during Category 2 events are not needed for part
60. First, for some design basis events, the repository design and
quality assurance enhancements employed to satisfy the proposed
requirements, for protection of members of the public, during Category
2 events, will also provide a measure of protection for onsite workers.
Second, onsite workers would have access to protective equipment (e.g.,
respirators) and clothing, should the need ever arise. Third, onsite
workers would be trained in emergency response and procedures to deal
with operational problems related to these kinds of events. Fourth,
part 20 should provide adequate worker protection standards.
There is one other matter the Commission would like to note in
relation to this action. During the course of consideration of the DOE
PRM and development of the amendments as proposed herein, the
Commission identified an additional regulatory uncertainty with respect
to part 60 requirements. Specifically, while part 60 includes a
definition for structures, systems, and components ``important to
safety,'' there is no corresponding definition in the rule for
structures, systems, and components ``important to waste isolation.''
These definitions are important as they are the predicates for required
design and quality assurance requirements in the rule. However, the
focus of the amendments proposed in this action is strictly in relation
to the adequacy of part 60 requirements to protect public health and
safety during the operational period of the repository. Recognizing
that the lack of a definition for ``important to waste isolation''
relates solely to the period of isolation following permanent
repository closure, the Commission plans to address this matter
separately in a subsequent rulemaking action. [[Page 15184]]
The proposed amendments are discussed below.
Section-by-Section Analysis
Section 60.2. Definitions
The proposed amendments involve eight definitions needed in part
60.
The term ``preclosure controlled area'' is new. It is essentially
the same as the term ``preclosure control area'' proposed by DOE in its
petition (PRM-60-3) and corresponds closely to the term ``controlled
area,'' as defined in 10 CFR 72.3. The term ``preclosure controlled
area'' is proposed because part 60 already refers to a ``controlled
area'' (within which waste isolation is to be ensured after permanent
closure). The function of the new term is to delimit an area over which
the licensee exercises control of activities to meet regulatory
requirements. Control includes the power to exclude members of the
public, if necessary. Because part 60 (unlike part 72) involves ongoing
underground operations and timeframes of concern over centuries and
millennia, language in the proposed definition is included that,
consistent with its function, limits the area to the surface and limits
the duration to the period up to, and including, permanent closure.
The existing term ``controlled area'' would be renamed
``postclosure controlled area,'' to avoid any confusion or
misunderstanding about this term, in relation to its use in parts 20
and 72. No substantive change, however, is intended for the
``postclosure controlled area,'' as this is a change in nomenclature,
only. Consistent with this change in nomenclature, the term
``controlled area'' would be changed to ``postclosure controlled
area,'' where it appears in the definitions for ``accessible
environment,'' ``disturbed zone,'' and ``site.''
The term ``important to safety'' would be amended to address the
issues previously discussed. The existing provision is unclear and
fails to ensure proper levels of protection of public and worker health
and safety for the broad range of conditions or events that might occur
at a repository site. This is an important term, because it is the
predicate for required design features, as well as required quality
assurance measures that provide defense-in-depth. The Commission
proposes to retain the quantitative features of the existing
definition, but specify different numerical limits for each of the two
categories (1 and 2) of design basis events. The structures, systems,
and components ``important to safety'' would be those necessary: (1) to
provide reasonable assurance that the requirements of Sec. 60.111(a)
would be observed for Category 1 design basis events; or (2) to prevent
or mitigate Category 2 design basis events that could result in doses
equal to, or greater than, the values specified in [new] Sec. 60.136,
to any individual located on or beyond the nearest boundary of the
preclosure controlled area.
Although the term ``design bases'' appears in existing part 60, in
10 CFR 60.21(c)(2), it was not defined. As the discussion above makes
clear, ``design bases'' should be understood in relation to that range
of events, including external natural or man-induced events, that is
taken into account in the design, and, in particular, in relation to
conditions that could result in radiological consequences beyond
specified limits. The definition in part 72 would be inserted, without
change, into the list of defined terms in 10 CFR 60.2.
The inclusion of a definition of ``design basis events'' serves two
purposes. First, it identifies a set of events (referred to elsewhere
as Category 1 design basis events) that must be taken into account in
demonstrating compliance with the requirement to show, with reasonable
assurance, that the provisions of part 20 will be met. (This set of
events is described as ``* * *those natural and human-induced events
that are reasonably likely to occur regularly, moderately frequently,
or one or more times before permanent closure of the geologic
repository operations area.'') Second, it identifies an additional set
of events (previously referred to as Category 2 design basis events)
that must be taken into account in applying the Commission's defense-
in-depth philosophy. (This set of events is described as those ``* *
*other natural and human-induced events that are considered unlikely,
but sufficiently credible to warrant consideration, taking into account
the potential for significant radiological impacts on public health and
safety.'') The Commission recognizes that the criterion of
``sufficiently credible to warrant consideration'' is inexact, leaving
its application to a consideration of the particular site and design
that are the subjects of a license application. Generally, the
Commission would expect that such design basis events would include as
broad a range of external phenomena as would be taken into account in
defining the design basis for other regulated facilities, including
nuclear reactors.
Section 60.8 Information Collection Requirements: OMB Approval
NRC is proposing to update 10 CFR 60.8, ``Information Collection
Requirements: OMB Approval,'' to reflect the fact that subsequent to
the original issuance of part 60, NRC requested, and obtained Office of
Management and Budget (OMB) approval for the part 60 ``Information
Collection Requirements.'' Section 60.8 was to be corrected the first
time other revisions were made.
Section 60.21 Content of Application
The petition for rulemaking suggested that provision for accident
analysis might be accomplished by amendment of 10 CFR 60.111. The
Commission proposes, instead, to provide for an accident analysis as
part of the content of the application section (i.e., 10 CFR 60.21).
The proposed language would require the application to address the
potential dose, to an individual on or beyond the preclosure controlled
area boundary, that is attributable to Category 2 design basis events.
The procedure that is envisaged is that the applicant would address the
critical design basis events, singly, and demonstrate, by its analysis,
that the doses on or beyond the preclosure controlled area boundary
would be in accordance with the applicable requirements. The proposed
language serves the same purpose as the counterpart section of part 72
(namely 10 CFR 72.24(m)).
The proposed rule also reflects the position, as discussed
previously, that the applicant must demonstrate that the requirements
of part 20 will be met, assuming the occurrence of Category 1 design
basis events. For this analysis, the applicant would consider Category
1 design basis events singly, or in appropriate combinations. The
doses, exposures, or releases must be kept within part 20 limits should
less likely events (e.g., moderately frequent events) occur in
combination with events that occur regularly.
The Commission also proposes to eliminate certain terms in part 60
that are undefined and may be subject to differing interpretations--
specifically, the terms ``normal conditions,'' ``anticipated
operational occurrences,'' and ``accidents.'' These terms would be
supplanted by the new term ``design basis events.'' Besides enhancing
clarity of expression, the new language better reflects the regulatory
framework articulated above. Lastly, where the term ``controlled area''
appears in the language of this section, it would be
[[Page 15185]] changed to ``postclosure controlled area.''
Section 60.43 License Specification
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.46 Particular Activities Requiring License Amendment
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.51 License Amendment for Permanent Closure
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.102 Concepts
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.111 Performance of the Geologic Repository Operations Area
Through Permanent Closure
Consistent with the petitioner's proposal, the Commission would
delete the phrase ``at all times'' from the performance objective of
Sec. 60.111(a). This change would clarify that this requirement does
not apply to radiation exposures, levels, and releases from Category 2
design basis events.
Section 60.121 Requirements for Ownership and Control of Interests in
Land
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.122 Siting Criteria
The term ``controlled area'' would be changed to ``postclosure
controlled area.''
Section 60.130 Scope of Design Criteria for the Geologic Repository
Operations Area
The Commission proposes to modify the title of this section to the
term ``General Considerations'' and add clarifying language, to the
existing discussion, to indicate that Secs. 60.131 through 60.134
specify the minimum criteria for the design of those structures,
systems, and components important to safety, or important to waste
isolation. These changes are necessary to provide consistency with the
modified definition of ``important to safety'' (10 CFR 60.2) as well as
to clarify the purpose of these criteria. These changes will also
provide consistency with the corresponding ``minimum'' design criteria,
for an MRS, in 10 CFR part 72.
Section 60.131 General Design Criteria for the Geologic Repository
Operations Area
Consistent with the modifications to Sec. 60.130, as described
above, the Commission would delete the reference to ``Structures,
systems, and components important to safety,'' in the title of
Sec. 60.131(b), and re-letter or re-number the current criteria in
Secs. 60.131(b)(1) through 60.131(b)(10), as appropriate. This change
would eliminate the confusion in the existing rule related to the
identification of only the criteria in Sec. 60.131(b) as ``important to
safety.'' It would also resolve the present incongruity with
Sec. 60.131(b)(7), ``Criticality control,'' regarding the reference to
waste ``isolation'' (a postclosure term) in the requirement.
The current rule employs the term ``normal and accident
conditions,'' or similar expression, in several places. However, the
conditions that must be addressed under this language are not well-
defined. The Commission proposes to remedy this situation by replacing
current terminology with references to ``design basis events,'' thereby
ensuring that the design appropriately takes into account the
consequences of all design basis events (i.e., as discussed in this
document, Category 1 and 2 design basis events). Accordingly,
modification of paragraphs (b)(5)(i), (b)(7), and (b)(8) is being
proposed for this section. The Commission would also revise the
language in 10 CFR 60.131(b)(1), which refers to ``anticipated''
natural phenomena and environmental conditions, so as to encompass all
design basis events. The ``necessary safety functions'' that must be
accommodated in the design, pursuant to that paragraph, include
whatever is necessary to meet the quantitative limits set out in the
Commission's rules (i.e., in 10 CFR 60.111(a) and 10 CFR 60.136).
Section 60.132 Additional Design Criteria for Surface Facilities in
the Geologic Repository Operations Area
Section 60.132(c)(1) requires that the surface facilities must be
``* * * designed to control the release of radioactive materials in
effluents during normal operations so as to meet the performance
objectives of Sec. 60.111(a).'' As indicated previously, the design
should ordinarily be sufficiently conservative so as to provide
reasonable assurance of meeting part 20 not only during normal
operations, but even for events that are likely to occur moderately
frequently or one or more times before permanent closure of the
geologic repository (i.e., all Category 1 design basis events).
Deleting the phrase ``during normal operations,'' as proposed, will
broaden the scope of this provision to reflect the Commission's intent
more accurately.
Section 60.133 Additional Design Criteria for the Underground Facility
As in the case of the changes proposed to 10 CFR 60.131, a
reference to design basis events would be substituted for the less
precise ``normal operations and * * * accident conditions.''
Section 60.136 Preclosure Controlled Area.
The proposed rule would adopt the petitioner's concept of a
preclosure control area under the name ``preclosure controlled area.''
The term would delimit an area over which the licensee exercises
control of activities to meet regulatory requirements. Control would
include the power to exclude members of the public, if necessary. The
zone, and related dose limits, would also be used to analyze and
identify structures, systems, and components that are important to
safety under unusual conditions that have heretofore been characterized
as Category 2 design basis events--credible, yet not likely to occur
during the period of operations. The issue that is presented concerns
the dose limits on or beyond the preclosure controlled area boundary
that are appropriate to ensure that the occurrence of any such events
presents no unreasonable risk to the health and safety of the public.
(Releases resulting from Category 1 design basis events would not be
permitted to cause doses exceeding the limits of part 20.) The
Commission proposes to adopt the basic provisions of part 72--namely, a
0.05-Sv (5-rem) dose limit, on or beyond the preclosure controlled area
boundary--as modified to reflect the part 20 system of dose limits (see
Sec. 20.1201(a)). In addition to providing for separate dose limits for
individual organs and tissue, the lens of the eye, and the skin, the
use of ``total effective dose equivalent'' (TEDE) in part 20 explicitly
accounts for exposures via the ingestion and inhalation dose pathways.
Modification of the 0.05-Sv (5-rem) dose limit, to reflect the part
20 system of dose limits, results in a family of dose limits: a TEDE of
0.05 Sv (5 rem); or the sum of the deep-dose equivalent and the
committed dose equivalent to any individual organ or tissue (other than
the lens of the eye) of 0.5 Sv (50 rem); an eye dose equivalent of 0.15
Sv (15 rem); and a shallow dose equivalent, to [[Page 15186]] skin, of
0.5 Sv (50 rem).1 The eye and skin dose limits are adequate to
ensure that no observable effects (e.g., induction of cataracts in the
lens of the eye) will occur as a result of any accidental radiation
exposure. In implementing this provision, dose calculations should be
made solely with reference to the consequence of the specific Category
2 design basis event, and not cumulatively with other design basis
events. To clarify this matter further, the analysis of a specific
Category 2 design basis event would require an analysis of an event
sequence or scenario which includes an initiating event (e.g., an
earthquake) and the associated combinations of repository system or
component failures that can potentially lead to exposure of the public
to radiation. An example sequence is a postulated earthquake (the
initiating event) which results in the failure of a crane lifting a
spent fuel waste package inside a waste handling building, the drop and
breach of the waste package, damage to the spent fuel and partitioning
of a fraction of the radionuclide inventory to the building atmosphere,
failure of the building filtration system, and public exposure to the
released radioactive material.
\1\Radiation exposure terminology is as used in part 20 (56 FR
23360; May 21, 1991).
---------------------------------------------------------------------------
The only other noteworthy deviation from part 72 (specifically 10
CFR 72.106) would be to refer to doses attributable to any ``design
basis event'' instead of any ``design basis accident.'' The term
``design basis event'' is used because it is a defined term in part 60.
The change in terminology is not intended to be one of substance as a
design basis accident is the consequence of some design basis event.
As discussed above, the 0.05 Sv (5 rem) dose limit is being
proposed by the Commission as the appropriate design basis for
protection of public health and safety from Category 2 design basis
events at a GROA and will harmonize part 60 with part 72. In this
regard, the Commission notes that part 72 applies to those facilities
(MRS installations) most similar to the surface facilities of a
repository and for which the kinds of design basis events are also
expected to be similar. Further, the proposed dose limit is consistent
with dose values (0.06 Sv [6 rem] to the whole body) established as
guidance for both fuel-handling accidents and spent-fuel cask-drop
accidents at nuclear power plants.2 Moreover, the proposed dose
limit is consistent with the accident-dose value (0.05 Sv [5 rem]
effective dose equivalent) proposed by DOE in its PRM.
\2\NUREG-0800, ``Standard Review Plan for the Review of Safety
Analysis Reports for Nuclear Power Plants,'' June 1987.
---------------------------------------------------------------------------
However, while consistency between the proposed 0.05 Sv (5 rem)
dose limit for part 60 and other Commission rules or guidance documents
is important, consistency alone does not necessarily ensure that there
would be no unreasonable risk to the health and safety of the public
associated with the proposed limit. As such, a perspective is provided
on the risks associated with an operational repository and the
appropriateness of the proposed 0.05 Sv (5 rem) dose limit as the
design basis for protection of public health and safety from Category 2
design basis events.
Based on estimates provided by the National Council on Radiation
Protection and Measurements (NCRP)3 the lifetime risk to
individuals in the general population is 0.05 fatal cancers per Seivert
(Sv) of exposure. Therefore, the lifetime risk of fatal cancer from an
assumed 0.05 Sv (5 rem) exposure resulting from a postulated Category 2
design basis event is 0.0025 (i.e., 2.5 x 10-3) per individual
exposed. While this assessment provides perspective on the risk
associated with a hypothetical exposure of a 0.05 Sv (5 rem) dose, it
does not provide perspective on the estimated actual risk associated
with the spectrum of possible Category 2 design basis events at a
repository during its operational lifetime (estimated to be about 100
years).
\3\National Council on Radiation Protection and Measurements,
``Risk Estimates for Radiation Protection,'' NCRP Report No. 115,
December 31, 1993.
---------------------------------------------------------------------------
Perspective on actual risk must include consideration of the
frequencies (i.e., probabilities) of occurrence of these events, as
well as their consequences, as ``risk'' is defined as the probability
of an event times its consequences. With respect to the range of
probabilities of Category 2 design basis events, the upper bound is
roughly 1 x 10-2 per year (i.e., event scenarios with
probabilities of occurrence greater than 1 x 10-2 per year would
generally be considered to be Category 1 events) and the lower bound is
considered to be on the order of 1 x 10-9 per year (i.e., event
scenarios with probabilities of occurrence less than 1 x 10-9
per year would generally be screened from further consideration due to
their negligible contribution to overall risk). Accordingly, assuming
event consequences equivalent to the proposed 0.05 Sv (5 rem) dose
limit for part 60, the hypothetical upper bound on individual risk is
2.5 x 10-5 fatal cancers per year. To put this risk in
perspective, the International Commission on Radiological
Protection4 notes that, based on a review of information related
to risks regularly accepted in everyday life for stochastic phenomena,
a fatal cancer risk in the range of 1 x 10-6 to 1 x 10-5
per year from exposure to radiation would likely be acceptable to
individual members of the public. Thus, while the risk associated with
repository event consequences at the proposed dose limit and bounding
probability of occurrence exceeds this range by a small factor, and is
at a level that the Commission considers safe for occupational
exposures, the Commission believes this result significantly
overestimates the actual risk of an operating repository.
\4\Recommendations of the International Commission on
Radiological Protection. ICRP Publication 26, January 1977.
---------------------------------------------------------------------------
Perspective on actual repository risk can be obtained by developing
an understanding of the spectrum of potential Category 2 design basis
events and estimating the consequences of these events as well as their
probabilities of occurrence. In this regard, the Commission recognizes
that there is no high-level waste repository operating experience and
that only conceptual designs have been developed for these facilities.
Nonetheless, some perspective can be gained from the preliminary risk
assessment by DOE5 of a conceptual design for a repository at
Yucca Mountain, Nevada, as well as from consideration of risk
assessments of selected U.S. nuclear power plants.6
\5\U.S. Department of Energy, ``Site Characterization Plan,
Yucca Mountain Site, Nevada Research and Development Area, Nevada,''
DOE/RW-0199, December 1988.
\6\NUREG-1150, ``Severe Accident Risks: An Assessment for Five
U.S. Nuclear Power Plants,'' December 1990.
---------------------------------------------------------------------------
Consistent with risk assessments for nuclear power plants, the
spectrum of possible repository design basis events includes both
internally and externally initiated events. Internally initiated events
would include waste transporter collisions, crane failures or other
types of fuel assembly, waste package or cask drop events, building or
facility exhaust filter fires, and exhaust filter bypass or failure.
Externally initiated events would include those resulting from
earthquakes, tornados, and flooding. Regardless of the type or nature
of the initiating event, the Commission believes that, for several
reasons, both the variety of credible event sequences and the resulting
potential consequences to members of the public will be somewhat
limited at repository facilities. First, in comparison with a
[[Page 15187]] nuclear power plant, an operating repository is a
relatively simple facility in which the primary activities are in
relation to waste receipt, handling, storage, and emplacement. A
repository does not require the variety and complexity of systems
necessary to support an operating nuclear power plant. Further, the
conditions are not present at a repository to generate a radioactive
source term of a magnitude that, however unlikely, is potentially
capable at a nuclear power plant (e.g., from a postulated loss of
coolant event). As such, the estimated consequences resulting from
limited source term generation at a repository would be correspondingly
limited. This conclusion is consistent with the results of the
aforementioned preliminary risk assessment by DOE of a conceptual
repository design at Yucca Mountain, Nevada. In that assessment, the
DOE considered 149 scenarios for a variety of internally and externally
initiated events. Of the 149 scenarios, only 7 resulted in offsite
doses in excess of 0.005 Sv (0.5 rem) to the critical organs of a
maximally exposed individual and also had associated probabilities of
occurrence greater than 1 x 10-9 per year. The highest estimated
offsite dose from the DOE risk assessment was 0.021 Sv (2.1 rem) with
an associated probability of occurrence of 5 x 10-7 per year.
The dose estimates of the DOE risk assessment are only reflective
of a conceptual design for a repository at Yucca Mountain, Nevada.
Nonetheless, the Commission believes they provide perspective on the
magnitude of the estimated consequences to members of the public from
postulated Category 2 design basis events and that variations in
repository design or site selection would not likely vary these
estimates by more than order of magnitude. The results of the DOE risk
assessment also provide some perspective on the estimated probabilities
of occurrence of the postulated repository design basis events and, as
such, perspective on actual risk from an operating repository.
In general, the Commission would expect the potential higher
consequence events to have correspondingly lower probabilities of
occurrence. This expectation is consistent with the results of the DOE
risk assessment as the estimated probabilities of occurrence for the 7
scenarios which resulted in offsite doses in excess of 0.005 Sv (0.5
rem) vary from 1 x 10-9 to 5 x 10-6 per year. The
corollary to the above is the expectation that higher frequency events
would have correspondingly lower offsite consequences and perspective
on actual risk from an operating repository necessitates consideration
of these events as well as lower frequency events. Review of the DOE
risk assessment indicates that some higher frequency, but lower
consequence, events are just as important to actual risk as the lower
frequency, but higher consequence, events. With respect to actual risk
from the broad spectrum of all events considered in the DOE risk
assessment, the estimated actual risk of an operating repository is
roughly two to three orders of magnitude lower than the range of fatal
cancer risks that would likely be acceptable to members of the public
(i.e., a fatal cancer risk of 1 x 10-6 to 1 x 10-5 per
year as noted in ICRP Publication 26).
With respect to the appropriateness of the proposed 0.05 Sv (5 rem)
dose limit for part 60 as the design basis for protection of public
health and safety from Category 2 design basis events, the DOE risk
assessment indicates the potential for events with offsite consequences
on the order of several hundredths to several tenths of Sv (several rem
to several tens of rem), depending on design and siting factors. The
event consequences in this range, coupled with the estimated event
probabilities of occurrence, result in estimated risks that would
likely be acceptable to members of the public. However, given the lack
of repository design, siting and operating experience and the
supporting data base for probabilistic risk assessment, the Commission
believes there is considerable uncertainty in the estimates of both the
consequences and the probabilities of occurrence of postulated Category
2 design basis events. As such, the Commission believes that
establishing a dose limit in part 60 to the proposed 0.05 Sv (5 rem)
value would provide an adequate margin of safety and an appropriate
design basis for protection of members of the public from unlikely, but
credible events. Further, the Commission believes that a singular dose
limit is appropriate for the broad range of possible event frequencies,
given the limited potential for offsite consequences at repository
facilities and the significant uncertainties in repository risk
assessment. Stated differently, the level of sophistication in
repository risk assessment does not presently exist to warrant a more
complex set of requirements in part 60 for protection of public health
and safety from postulated Category 2 design basis events.
Notwithstanding these views and the Commission's parallel interest in
harmonizing part 60 and part 72, the Commission specifically seeks
public comment on (1) the appropriateness of the proposed 0.05 Sv (5
rem) dose limit in Section 60.136 as the design basis for protection of
public health and safety, and (2) the rationale, as discussed herein,
supporting the proposed 0.05 Sv (5 rem) dose limit.
Section 60.183 Criminal Penalties
A conforming change has been made to this section, to include
Sec. 60.136 (pertaining to the preclosure controlled area) among the
regulations that are not issued under Sections 161b, 161i, or 161o of
the Atomic Energy Act, for purposes of section 223 of the Act.
Environmental Impact: Categorical Exclusion
NRC has determined that this proposed regulation is the type of
action described in 10 CFR 51.22 (c)(2), pertaining to the promulgation
of technical requirements and criteria that the Commission will apply
in approving or disapproving applications under part 60. Therefore,
neither an environmental impact statement nor an environmental
assessment has been prepared for this proposed regulation.
Paperwork Reduction Act Statement
This proposed rule does not contain a new or amended information
collection requirement subject to the Paperwork Reduction Act of 1980
(44 U.S.C. 3501, et seq.). Existing requirements were approved by the
Office of Management and Budget, approval number 3150-0127.
Regulatory Analysis
The Commission has prepared a draft regulatory analysis on this
proposed regulation. The analysis examines the costs and benefits of
the alternatives considered by the Commission. The draft analysis is
available for inspection in the NRC Public Document Room, 2120 L Street
NW. (Lower Level), Washington, DC. Single copies of the draft analysis
may be obtained from Dr. Richard A. Weller, U.S. Nuclear Regulatory
Commission, Office of Nuclear Material Safety and Safeguards, Division
of Waste Management, Washington, DC 20555, Telephone (301) 415-7287.
Regulatory Flexibility Certification
As required by the Regulatory Flexibility Act of 1980, 5 U.S.C.
605(b), the Commission certifies that this rule, if adopted, will not
have a significant economic impact on a substantial number of small
entities. The only entity subject to regulation under this rule is
DOE. [[Page 15188]]
Backfit Analysis
NRC has determined that the backfit rule, 10 CFR 50.109, does not
apply to this proposed rule and, therefore, that a backfit analysis is
not required for this proposed rule, because these amendments do not
involve any provisions that would impose backfits as defined in 10 CFR
50.109(a)(1).
List of Subjects in 10 CFR Part 60
Criminal penalties, High-level waste, Nuclear power plants and
reactors, Nuclear materials, Reporting and recordkeeping requirements,
and Waste treatment and disposal.
For the reasons set out in the preamble and under the authority of
the Atomic Energy Act of 1954, as amended, the Energy Reorganization
Act of 1974, as amended, the Nuclear Waste Policy Act of 1982, as
amended, and 5 U.S.C. 553, NRC is proposing to adopt the following
amendments to 10 CFR part 60.
PART 60--DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC
REPOSITORIES
1. The authority citation for part 60 continues to read as follows:
Authority: Secs. 51, 53, 62, 63, 65, 81, 161, 182, 183, 68 Stat.
929, 930, 932, 933, 935, 948, 953, 954, as amended (42 U.S.C. 2071,
2073, 2092, 2093, 2095, 2111, 2201, 2232, 2233); secs. 202, 206, 88
Stat. 1244, 1246 (42 U.S.C. 5842, 5846); secs. 10 and 14, Pub. L.
95-601, 92 Stat. 2951 (42 U.S.C. 2021a and 5851); Sec. 102, Pub. L.
91-190, 83 Stat. 853 (42 U.S.C. 4332); Secs. 114, 121, Pub. L. 97-
425, 96 Stat. 2213g, 2228, as amended (42 U.S.C. 10134, 10141).
2. Section 60.2 is amended by adding definitions of ``Design
bases,'' ``Design basis events,'' and ``Preclosure controlled area,''
revising the definitions of ``Accessible environment,'' ``Disturbed
zone,'' ``Important to safety,'' and ``Site,'' renaming the defined
term ``Controlled area'' to ``Postclosure controlled area,'' and
alphabetizing the definitions to read as follows:
Sec. 60.2 Definitions.
* * * * *
Accessible environment means: (1) The atmosphere, (2) the land
surface, (3) surface water, (4) oceans, and (5) the portion of the
lithosphere that is outside the postclosure controlled area.
* * * * *
Design bases means that information that identifies the specific
functions to be performed by a structure, system, or component of a
facility and the specific values or ranges of values chosen for
controlling parameters as reference bounds for design. These values may
be restraints derived from generally accepted ``state-of-the-art''
practices for achieving functional goals or requirements derived from
analysis (based on calculation or experiments) of the effects of a
postulated event under which a structure, system, or component must
meet its functional goals. The values for controlling parameters for
external events include:
(1) estimates of severe natural events to be used for deriving
design bases that will be based on consideration of historical data on
the associated parameters, physical data, or analysis of upper limits
of the physical processes involved; and
(2) estimates of severe external man-induced events, to be used for
deriving design bases, that will be based on analysis of human activity
in the region, taking into account the site characteristics and the
risks associated with the event.
Design basis events means:
(1) those natural and human-induced events that are reasonably
likely to occur regularly, moderately frequently, or one or more times
before permanent closure of the geologic repository operations area;
and
(2) other natural and man-induced events that are considered
unlikely, but sufficiently credible to warrant consideration, taking
into account the potential for significant radiological impacts on
public health and safety.
The events described in paragraph (1) of this definition are
referred to as ``Category 1'' design basis events. The events described
in paragraph (2) of this definition are referred to as ``Category 2''
design basis events.
* * * * *
Disturbed zone means that portion of the postclosure controlled
area the physical or chemical properties of which have changed as a
result of underground facility construction or as a result of heat
generated by the emplaced radioactive wastes such that the resultant
change of properties may have a significant effect on the performance
of the geologic repository.
* * * * *
Important to safety, with reference to structures, systems, and
components, means those features of the repository whose function is:
(1) to provide reasonable assurance that high-level waste can be
received, handled, packaged, stored, emplaced, and retrieved without
exceeding the requirements of Sec. 60.111(a) for Category 1 design
basis events; or
(2) to prevent or mitigate Category 2 design basis events that
could result in doses equal to or greater than the values specified in
Sec. 60.136 to any individual located on or beyond the nearest boundary
of the preclosure controlled area.
* * * * *
Postclosure controlled area means a surface location, to be marked
by suitable monuments, extending horizontally no more than 10
kilometers in any direction from the outer boundary of the underground
facility, and the underlying subsurface, which area has been committed
to use as a geologic repository and from which incompatible activities
would be restricted following permanent closure.
* * * * *
Preclosure controlled area means that surface area immediately
surrounding the geologic repository operations area for which the
licensee exercises authority over its use, in accordance with the
provisions of this part, until permanent closure has been completed.
* * * * *
Site means the location of the postclosure controlled area.
3. Section 60.8 is revised to read as follows:
Sec. 60.8 Information collection requirements: OMB approval.
(a) The Nuclear Regulatory Commission has submitted the information
collection requirements of general applicability contained in this part
to the Office of Management and Budget (OMB) for approval as required
by the Paperwork Reduction Act of 1980 (44 U.S.C. 3501, et seq.). OMB
has approved the information collection requirements contained in this
part under control number 3150-0127.
(b) The approved information collection requirements contained in
this part appear in Secs. 60.62, 60.63, and 60.65.
4. In Sec. 60.21, paragraphs (c)(1)(i), (c)(1)(ii)(B), (c)(3), and
(c)(8) are revised to read as follows:
Sec. 60.21. Content of application.
* * * * *
(c) * * *
(1) * * *
(i) The description of the site shall also include the following
information regarding subsurface conditions. This description shall, in
all cases, include such information with respect to the postclosure
controlled area. In addition, where subsurface conditions outside the
postclosure controlled area may affect isolation within the postclosure
controlled area, the description shall include such information with
respect to subsurface conditions outside the postclosure controlled
area to the extent such information is relevant and
[[Page 15189]] material. The detailed information referred to in this
paragraph shall include:
(A) the orientation, distribution, aperture in-filling and origin
of fractures, discontinuities, and heterogeneities;
(B) the presence and characteristics of other potential pathways
such as solution features, breccia pipes, or other potentially
permeable features;
(C) the geomechanical properties and conditions, including pore
pressure and ambient stress conditions;
(D) the hydrogeologic properties and conditions;
(E) the geochemical properties; and
(F) the anticipated response of the geomechanical, hydrogeologic,
and geochemical systems to the maximum design thermal loading, given
the pattern of fractures and other discontinuities and the heat
transfer properties of the rock mass and groundwater.
(ii) * * *
(B) Analyses to determine the degree to which each of the favorable
and potentially adverse conditions, if present, has been characterized,
and the extent to which it contributes to or detracts from isolation.
For the purpose of determining the presence of the potentially adverse
conditions, investigations shall extend from the surface to a depth
sufficient to determine critical pathways for radionuclide migration
from the underground facility to the accessible environment.
Potentially adverse conditions shall be investigated outside of the
postclosure controlled area if they affect isolation within the
postclosure controlled area.
* * * * *
(3) A description and analysis of the design and performance
requirements for structures, systems, and components of the geologic
repository that are important to safety. The analysis must include a
demonstration that--(i) the requirements of Sec. 60.111(a) will be met,
assuming occurrence of Category 1 design basis events; and (ii) the
requirements of Sec. 60.136 will be met, assuming occurrence of
Category 2 design basis events.
* * * * *
(8) A description of the controls that the applicant will apply to
restrict access and to regulate land use at the site and adjacent
areas, including a conceptual design of monuments which would be used
to identify the postclosure controlled area after permanent closure.
* * * * *
Sec. 60.43 [Amended]
5. In Sec. 60.43(b)(5), the term ``controlled area'' is revised to
read ``postclosure controlled area.''
Sec. 60.46 [Amended]
6. In Sec. 60.46(a)(3), the term ``controlled area'' is revised to
read ``postclosure controlled area wherever it appears.''
Sec. 60.51 [Amended]
7. In Sec. 60.51(a)(2)(i) and (a)(2)(ii), the term ``controlled
area'' is revised to read ``postclosure controlled area.''
Sec. 60.102 [Amended]
8. In Sec. 60.102(c), the term ``controlled area'' is revised to
read ``postclosure controlled area.''
9. In Sec. 60.111, paragraph (a) is revised to read as follows:
Sec. 60.111. Performance of the geologic repository operations area
through permanent closure.
(a) Protection against radiation exposures and releases of
radioactive material. The geologic repository operations area shall be
designed so that until permanent closure has been completed, radiation
exposures and radiation levels, and releases of radioactive materials
to unrestricted areas, will be maintained within the limits specified
in part 20 of this chapter and such generally applicable environmental
standards for radioactivity as may have been established by the
Environmental Protection Agency.
* * * * *
Sec. 60.121 [Amended]
10. In Sec. 60.121(a) and (b), the term ``controlled area'' is
revised to read ``postclosure controlled area.''
Sec. 60.122 [Amended]
11. In Sec. 60.122(b)(6) and (c) introductory text, the term
``controlled area'' is revised to read ``postclosure controlled area.''
12. Section 60.130 is revised to read as follows:
Sec. 60.130 General considerations.
Pursuant to the provisions of Sec. 60.21(c)(2)(i), an application
to receive, possess, store, and dispose of high-level radioactive waste
in the geologic repository operations area must include the principal
design criteria for a proposed facility. The principal design criteria
establish the necessary design, fabrication, construction, testing,
maintenance, and performance requirements for structures, systems, and
components important to safety and/or important to waste isolation.
Sections 60.131 through 60.134 specify minimum requirements for the
principal design criteria for the geologic repository operations area.
These design criteria are not intended to be exhaustive, however.
Omissions in Secs. 60.131 through 60.134 do not relieve DOE from any
obligation to provide such features in a specific facility needed to
achieve the performance objectives.
13. In Sec. 60.131, paragraph (b) is revised, and paragraphs (c)
through (k) are added to read as follows:
Sec. 60.131 General design criteria for the geologic repository
operations area.
* * * * *
(b) Protection against design basis events. The structures,
systems, and components important to safety shall be designed so that
they will perform their necessary safety functions, assuming occurrence
of design basis events.
(c) Protection against dynamic effects of equipment failure and
similar events. The structures, systems, and components important to
safety shall be designed to withstand dynamic effects such as missile
impacts, that could result from equipment failure, and similar events
and conditions that could lead to loss of their safety functions.
(d) Protection against fires and explosions. (1) The structures,
systems, and components important to safety shall be designed to
perform their safety functions during and after credible fires or
explosions in the geologic repository operations area.
(2) To the extent practicable, the geologic repository operations
area shall be designed to incorporate the use of noncombustible and
heat resistant materials.
(3) The geologic repository operations area shall be designed to
include explosion and fire detection alarm systems and appropriate
suppression systems with sufficient capacity and capability to reduce
the adverse effects of fires and explosions on structures, systems, and
components important to safety.
(4) The geologic repository operations area shall be designed to
include means to protect systems, structures, and components important
to safety against the adverse effects of either the operation or
failure of the fire suppression systems.
(e) Emergency capability. (1) The structures, systems, and
components important to safety shall be designed to maintain control of
radioactive waste and radioactive effluents, and permit prompt
termination of operations and evacuation of personnel during an
emergency. [[Page 15190]]
(2) The geologic repository operations area shall be designed to
include onsite facilities and services that ensure a safe and timely
response to emergency conditions and that facilitate the use of
available offsite services (such as fire, police, medical, and
ambulance service) that may aid in recovery from emergencies.
(f) Utility services. (1) Each utility service system that is
important to safety shall be designed so that essential safety
functions can be performed, assuming occurrence of the design basis
events.
(2) The utility services important to safety shall include
redundant systems to the extent necessary to maintain, with adequate
capacity, the ability to perform their safety functions.
(3) Provisions shall be made so that, if there is a loss of the
primary electric power source or circuit, reliable and timely emergency
power can be provided to instruments, utility service systems, and
operating systems, including alarm systems, important to safety.
(g) Inspection, testing, and maintenance. The structures, systems,
and components important to safety shall be designed to permit periodic
inspection, testing, and maintenance, as necessary, to ensure their
continued functioning and readiness.
(h) Criticality control. All systems for processing, transporting,
handling, storage, retrieval, emplacement, and isolation of radioactive
waste shall be designed to ensure that nuclear criticality is not
possible unless at least two unlikely, independent, and concurrent or
sequential changes have occurred in the conditions essential to nuclear
criticality safety. Each system must be designed for criticality safety
assuming occurrence of design basis events. The calculated effective
multiplication factor (keff) must be sufficiently below unity to show
at least a 5 percent margin, after allowance for the bias in the method
of calculation and the uncertainty in the experiments used to validate
the method of calculation.
(i) Instrumentation and control systems. The design shall include
provisions for instrumentation and control systems to monitor and
control the behavior of systems important to safety, assuming
occurrence of design basis events.
(j) Compliance with mining regulations. To the extent that DOE is
not subject to the Federal Mine Safety and Health Act of 1977, as to
the construction and operation of the geologic repository operations
area, the design of the geologic repository operations area shall
nevertheless include such provisions for worker protection as may be
necessary to provide reasonable assurance that all structures, systems,
and components important to safety can perform their intended
functions. Any deviation from relevant design requirements in 30 CFR,
Chapter I, Subchapters D, E, and N will give rise to a rebuttable
presumption that this requirement has not been met.
(k) Shaft conveyances used in radioactive waste handling. (1)
Hoists important to safety shall be designed to preclude cage free
fall.
(2) Hoists important to safety shall be designed with a reliable
cage location system.
(3) Loading and unloading systems for hoists important to safety
shall be designed with a reliable system of interlocks that will fail
safely upon malfunction.
(4) Hoists important to safety shall be designed to include two
independent indicators to indicate when waste packages are in place and
ready for transfer.
14. In Sec. 60.132, paragraph (c)(1) is revised to read as follows:
Sec. 60.132. Additional design criteria for surface facilities in the
geologic repository operations area.
* * * * *
(c) Radiation control and monitoring--(1) Effluent control. The
surface facilities shall be designed to control the release of
radioactive materials in effluents so as to meet the performance
objectives of Sec. 60.111(a).
* * * * *
15. In Sec. 60.133, the introductory text of paragraph (g) and
paragraph (g)(2) are revised to read as follows:
Sec. 60.133 Additional design criteria for the underground facility.
* * * * *
(g) Underground facility ventilation. The ventilation system shall
be designed to:
* * * * *
(2) Assure the ability to perform essential safety functions
assuming occurrence of design basis events; and
* * * * *
16. A new undesignated center heading and Sec. 60.136 are added to
read as follows:
Preclosure Controlled Area
Sec. 60.136 Preclosure controlled area.
(a) A preclosure controlled area must be established for the
geologic repository operations area.
(b) The geologic repository operations area shall be designed so
that, for Category 2 design basis events, no individual located on or
beyond the nearest boundary of the preclosure controlled area will
receive the more limiting of a total effective dose equivalent of 0.05
Sv (5 rem), or the sum of the deep-dose equivalent and the committed
dose equivalent to any individual organ or tissue (other than the lens
of the eye) of 0.5 Sv (50 rem). The eye dose equivalent may not exceed
0.15 Sv (15 rem), and the shallow dose equivalent to skin may not
exceed 0.5 Sv (50 rem). The minimum distance from the surface
facilities in the geologic repository operations area to the boundary
of the preclosure controlled area must be at least 100 meters.
(c) The preclosure controlled area may be traversed by a highway,
railroad, or waterway, so long as appropriate and effective
arrangements are made to control traffic and to protect public health
and safety.
17. In Sec. 60.183, paragraph (b) is revised to read as follows:
Sec. 60.183 Criminal penalties.
* * * * *
(b) The regulations in part 60 that are not issued under sections
161b, 161i, or 161o for the purposes of section 223 are as follows:
Secs. 60.1, 60.2, 60.3, 60.5, 60.6, 60.7, 60.8, 60.15, 60.16, 60.17,
60.18, 60.21, 60.22, 60.23, 60.24, 60.31, 60.32, 60.33, 60.41, 60.42,
60.43, 60.44, 60.45, 60.46, 60.51, 60.52, 60.61, 60.62, 60.63, 60.64,
60.65, 60.101, 60.102, 60.111, 60.112, 60.113, 60.121, 60.122, 60.130,
60.131, 60.132, 60.133, 60.134, 60.135, 60.136, 60.137, 60.140, 60.141,
60.142, 60.143, 60.150, 60.151, 60.152, 60.162, 60.181, and 60.183.
Dated in Rockville, Maryland, this 15th day of March, 1995.
For the Nuclear Regulatory Commission.
John C. Hoyle,
Secretary of the Commission.
[FR Doc. 95-6872 Filed 3-21-95; 8:45 am]
BILLING CODE 7590-01-P