[Federal Register Volume 66, Number 200 (Tuesday, October 16, 2001)]
[Proposed Rules]
[Pages 52551-52554]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25958]


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NUCLEAR REGULATORY COMMISSION

10 CFR Parts 20 and 50

RIN 3150-AG89


Entombment Options for Power Reactors

AGENCY: Nuclear Regulatory Commission.

ACTION: Advance notice of proposed rulemaking.

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SUMMARY: The Nuclear Regulatory Commission (NRC) is considering an 
amendment to its regulations that would clarify the use of entombment 
for power reactors. The NRC has determined that entombment of power 
reactors is a technically viable decommissioning alternative and can be 
accomplished safely. Current regulations governing decommissioning and 
license termination require that decommissioning be completed within 60 
years of permanent cessation of operations. Completion of 
decommissioning beyond 60 years will be approved by the NRC only when 
necessary to protect public health and safety. The regulations also 
establish dose criteria for license termination that includes a 
provision that permits license termination under restricted and 
unrestricted release conditions. This advance notice of proposed 
rulemaking invites early input from affected parties and the public on 
the issues surrounding the feasibility of entombment.

DATES: The comment period expires December 31, 2001. Comments received 
after this date will be considered if it is practical to do so, but the 
Commission is able to assure consideration only for comments received 
on or before this date.

ADDRESSES: Mail comments to: The Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, Attention: Rulemakings and 
Adjudications Staff. Deliver comments to: 11555 Rockville Pike, 
Rockville, Maryland, between 7:30 a.m. and 4:15 p.m. on Federal 
workdays. You may also provide comments via the NRC's interactive 
rulemaking Web site (http://ruleforum.llnl.gov). This site provides the 
availability to upload comments as files (any format), if your web 
browser supports that function. For information about the interactive 
rulemaking site, contact Ms. Carol Gallagher (301) 415-5905; e-mail 
[email protected].
    The NRC maintains an Agency wide Documents Access and Management 
System (ADAMS), which provides text and image files of NRC's public 
documents. These documents may be accessed through the NRC's Public 
Electronic Reading Room on the Internet at http://www.nrc.gov/NRC/ADAMS/index.html. If you do not have access to ADAMS or if there are 
problems in accessing the documents located in ADAMS, contact the NRC 
Public Document Room (PDR) Reference staff at 1-800-397-4209, 301-415-
4737 or by email to [email protected]. 

FOR FURTHER INFORMATION CONTACT: Frank Cardile, telephone (301) 415-
6185, e-mail [email protected], Office of Nuclear Material Safety and 
Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001.

SUPPLEMENTARY INFORMATION:

Background

A. Current Rulemakings Related to Decommissioning and License 
Termination

    Current requirements pertaining to decommissioning are contained in 
10 CFR part 50. Specific requirements on decommissioning alternatives 
were published June 27, 1988 (53 FR 24018). These provisions state that 
the Commission will terminate a license if it determines that the 
decommissioning has been performed in accordance with an approved 
decommissioning plan and that terminal radiation surveys and associated 
documentation demonstrate that the facility and site are suitable for 
release for unrestricted release. The Supplementary Information (SI) to 
the 1988 rule defined three broad decommissioning alternatives: DECON, 
SAFSTOR, and ENTOMB. The term ENTOMB was defined as the alternative, in 
which radioactive contaminants are encased in a structurally long-lived 
material, such as concrete; the entombed structure is appropriately 
maintained; and surveillance is continued until the radioactivity 
decays to a level permitting termination of the license with 
unrestricted release.
    Currently, 10 CFR 50.82(a)(3) requires that decommissioning be 
completed within 60 years of permanent cessation of operations, and 
completion of decommissioning beyond 60 years be approved by the NRC 
only when necessary to protect public health and safety. The factors 
that will be considered by the Commission in evaluating an alternative 
that provides for the completion of decommissioning beyond 60 years of 
permanent cessation of operation include unavailability of waste 
disposal capacity and other site-specific factors affecting the 
licensee's capability to carry out decommissioning, including the 
presence of other nuclear facilities at the site. In addition, the 1988 
rule was structured so that use of any decommissioning option would 
result in termination of the license for unrestricted use. These 
requirements tended to favor the use of DECON and SAFSTOR. However, as 
noted in the SI for the June 27, 1988, final rule, the ENTOMB 
alternative was not specifically precluded because it was recognized 
that it might be an allowable alternative in protecting public health 
and safety.
    In 1997, the Commission amended its regulations to establish dose 
criteria for license terminations. These provisions appear in 10 CFR 
Part 20, Subpart E, and include a provision that permits license 
termination under restricted release conditions. Under a restricted 
release, the dose to the average member of the critical group must not 
exceed 0.25 mSv/yr ( 25 mrem/yr) total effective dose equivalent (TEDE) 
and be as low as reasonably achievable (ALARA) with the restrictions in 
place, and, if the restrictions were no longer in effect, the dose due 
to residual radioactivity could not exceed 1 mSv/yr (100 mrem/yr) (or 5 
mSv/yr (500 mrem/yr), if additional conditions are met) TEDE and is 
ALARA. These caps were chosen to provide a safety net in the highly 
unlikely event that the restrictions failed.

B. Discussion of the Concept of Entombment

    Entombment is an alternative method for decommissioning a power 
reactor that ultimately results in termination of the license. Before 
the start of entombment, the reactor permanently

[[Page 52552]]

ceases operations. The spent fuel is permanently removed from the 
reactor core and either shipped offsite or stored in an independent 
spent fuel storage installation. After preliminary decommissioning 
activities are completed, radioactive contaminants to be left on-site 
are placed, or left, in the reactor containment building or other 
structure.
    After the radioactive materials are placed in the containment, the 
material is entombed by designing and constructing engineered barriers 
that can reliably isolate the radioactive contaminants from the 
environment. This can be accomplished by suitable hardening to prevent 
inadvertent intrusion into the containment (e.g., use of concrete 
capping, or fill materials) and mitigation of transport of 
radionuclides to the environment (e.g., use of soil, added sorption 
materials, site considerations).
    The length of time that the entombed structure must remain 
effective in isolating its contents depends on the specific 
radionuclides present in the entombed structure and the time necessary 
for those radionuclides to be reduced, through radioactive decay, to a 
level that is acceptable for license termination.
    For radionuclides Cobalt-60 and Cesium-137 (with half-lives of 
approximately 5.3 and 30 years, respectively), which are the principal 
dose contributors for reactors, the time estimated to reach the 0.25 
mSv/yr (25 mrem/yr) unrestricted use criterion is about 160 and 300 
years, respectively. If the long-lived activation products present in 
reactor internals were included in an entombed structure, the time of 
isolation for the long-lived activation products will depend not only 
on their half-lives but other site-specific factors, such as engineered 
barriers and site characteristics.
    Additional information about the entombment concept, including 
studies and previous NRC papers can be located on the web at 
www.nrc.gov/NMSS/IMNS/entombment.html. 

Specific Proposal

    The NRC believes that decommissioning a power reactor using the 
entombment approach appears to be a safe and viable option for many 
situations, and that it could offer benefits and greater flexibility to 
accommodate particular site-specific decommissioning situations. In 
some cases, reactors may be able to achieve decommissioning through an 
entombment approach to license termination in accordance with the 
criteria of the license termination rule in 10 CFR part 20, subpart E, 
and within the 60-year timeframe provided in 10 CFR 50.82(a)(3). 
However, in other cases, the 60-year provision in Sec. 50.82(a)(3) for 
completion of decommissioning may need to be revised to reflect the 
period of time required for reduction in dose to meet the restricted 
release criteria in 10 CFR part 20, subpart E. Thus, the use of an 
entombment approach may require changes to the regulatory requirements 
and guidance before this option can be treated as a generic 
alternative.

Specific Considerations

    Before it prepares a proposed rule on the subject, the NRC is 
seeking advice and recommendations on this matter from all interested 
persons. Specific areas on which the Commission is requesting comment 
are discussed in the following sections. Comments accompanied by 
supporting reasons are particularly requested on the questions 
contained in each section.

A. Regulatory Framework and Approaches--Rulemaking Options

Option 1

    Do not conduct rulemaking. Currently, 10 CFR 50.82(a)(3) requires 
that decommissioning be completed within 60 years of permanent 
cessation of operations. Completion of decommissioning beyond 60 years 
may be approved by the NRC only when necessary to protect public health 
and safety. To extend decommissioning based on economic or other non-
public health and safety reasons would require an exemption under 10 
CFR 50.12.
    The advantage of this option is that current regulations already 
permit case-specific Commission approval for completing license 
termination beyond 60 years (10 CFR 50.82) based on health and safety 
considerations. In addition, the current regulations (10 CFR part 20, 
subpart E) for license termination with restricted release provide dose 
criteria for decommissioning and, in some cases, could apply to 
entombment within the existing time frame of 10 CFR 50.82.
    The disadvantage of this option is that current 10 CFR part 20 
subpart E requirements for license termination with restricted release 
may not be sufficiently flexible in some cases to achieve license 
termination within the 60-year period specified, given the limitations 
for extending the time period. Therefore, this option results in 
regulating by exemption. Also, additional resources would be requested 
to process the site-specific exemptions for extension of time if the 
current rules were used for considering the permissibility of 
entombment for case-specific situations for other than public health 
and safety reasons. Another disadvantage is that this option does not 
address the disposition of Greater Than Class C (GTCC) material, which 
otherwise might need to be disposed of in an offsite disposal facility. 
Finally, under 10 CFR part 20, the entombment contains residual 
radioactivity and is considered to be suitable for license termination. 
However, under other statutes, the residual radioactivity might be 
considered low level waste (LLW). Classification of the entombed 
material as LLW would raise issues concerning State and LLW compact 
legal authority over the entombment. For example, States and compacts 
have authority for disposal of LLW and might prescribe means for its 
disposal other than entombment. In addition, some States have 
prescribed their own criteria for LLW disposal that may not be 
compatible with those in an entombment rule.

Option 2

    Another option would be to conduct rulemaking to consider the need 
to add flexibility to 10 CFR 50.82 to amend the 60-year time frame for 
completion of decommissioning and to clarify the use of engineered 
barriers for reactor entombments.
    Option 2 would modify the 60-year time period for completion of 
decommissioning activities. Under this option, the ``Statement of 
Considerations'' could clarify when credit could be taken for 
engineered barriers, independent of institutional controls, as a method 
for meeting the established dose criteria found in 10 CFR part 20, 
subpart E.\1\ Engineered barrier system objectives, qualifying 
criteria, and implementation acceptability by the NRC could be 
specified in the rule to ensure a high level of confidence that the 
entombment would continue to isolate the radioactive material until it 
decays to a level that would be acceptable for restricted or 
unrestricted release. This option could specifically authorize the use 
of entombment for power reactors as a decommissioning alternative for 
license termination.
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    \1\ Under 20 CFR part 20, subpart E, engineered barriers may be 
considered institutional controls depending upon the need for and 
the degree of human involvement to maintain their effectivness. 
Option 2, unlike Option 1, would clarify this issue.
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    The advantage of this option is that amending 10 CFR 50.82 would 
provide more flexibility for terminating a license without the need for 
exemptions or Commission approval of alternative

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schedules. It also permits flexibility in defining requirements to meet 
a broad variety of possible situations, which would result in resource 
savings. The use of engineered barriers would be clarified in the 
regulations. Furthermore, terminating the license is more efficient and 
effective than retaining a disposal license, as proposed by Option 3 
below.
    The disadvantages of this option are that there may not be a 
defined time period for license termination and this approach may delay 
completion of decommissioning and license termination. However, there 
may be other factors that would motivate timely completion of 
decommissioning activities, such as continued requirements for payment 
of fees, insurance, and other resource impacts on licensees. Another 
disadvantage, as in Option 1, is that Option 2 does not address the 
disposition of GTCC material, which otherwise might need to be disposed 
of in an offsite disposal facility. Finally, under 10 CFR part 20, the 
entombment contains residual radioactivity and is considered to be 
suitable for license termination. However, under other statutes, the 
residual radioactivity might be considered LLW. Classification of the 
entombed material as LLW would raise issues concerning State and LLW 
compact legal authority over the entombment. For example, States and 
compacts have authority for disposal of LLW and might prescribe means 
for its disposal other than entombment. In addition, some States have 
prescribed their own criteria for LLW disposal that may not be 
compatible with those in an entombment rule.

Option 3

    A third option would be to conduct a rulemaking to establish 
performance objectives and licensing requirements for an entombed 
facility. This option can be characterized as disposal, rather than 
decommissioning leading to license termination. It would provide for a 
rulemaking to establish performance objectives and technical 
requirements under a new or existing part of the regulations for an 
entombed facility. Relevant requirements established in other existing 
parts of the NRC regulations (e.g., part 20, subpart E, and 10 CFR part 
61) could be incorporated into this rulemaking. These requirements 
could include, but would not be limited to, overall system performance 
objectives, institutional controls, including Federal or State 
ownership/oversite, and analyses of the long-term stability of the 
site. These requirements could also include pathway analysis to 
demonstrate protection of the average member of the critical group from 
releases of radioactivity using dose limits, which could include 
provisions for adequate barriers to prevent inadvertent intrusion. In 
addition, provisions for engineering features such as barrier controls 
could be established on a site-specific, license-specific basis. The 
license could also cover the activities of entombing the radioactive 
material, operations, and surveillance of controls. Similar to a 
license under Part 61, the entombed disposal facility would be 
maintained under an NRC license until the post-closure requirements 
were met. Also, since the facility would no longer be a licensed power 
reactor, but rather a new license, this option could apply to other 
types of facilites.
    The advantage of this option is that it would allow for on-site 
disposal of GTCC waste, since such waste may only be disposed of at an 
NRC-licensed facility. This option would address a dose analysis period 
that may be necessary for GTCC waste. It might also provide an approach 
more acceptable to the public because entombing a large quantity of 
long-lived isotopes is viewed as more akin to disposal or burial of 
waste rather than leaving behind residual material in decommissioning. 
It could also address other license terminations with large source 
terms requiring extended periods of institutional controls. 
Furthermore, because no NRC-licensed power reactors have ever been 
entombed, continuation of an NRC license would permit greater 
confidence that the dose criteria would be met.
    A disadvantage of this option is that it does not terminate the 
license. It could also require major expenditures of NRC and licensee 
resources to write a new part to the regulations and to re-license or 
convert the facility license. It could also require major expenditures 
to maintain the NRC license over the period of time during which the 
license would need to be retained. It may have complex policy 
implications because NRC's responsibility is to license GTCC disposal 
facilities, subject to DOE's overall responsibilities for disposal 
strategies of GTCC material. Finally, classification of the entombed 
material as LLW might raise issues concerning State and LLW compact 
legal authority over the entombment.
    Based on this discussion:

    A.1. Does the existing 10 CFR 50.82(a)(3) provide an adequate 
basis to allow periods of entombment beyond 60 years. If not, in 
what way should the regulations be changed?
    A.2. Is 10 CFR part 20, subpart E, adequate to achieve license 
termination using an entombment approach? If not, how and why should 
this rule be modified?
    A.3. Should entombed facilities be required to maintain some 
type of NRC license after the facility meets the dose criteria of 
part 20, subpart E? If so, what conditions need to prevail before 
the license may be terminated? What alternatives might exist for 
adequately managing the radioactive materials left in the entombed 
structure?
    A.4. new part is being considered in the regulations to 
establish performance objectives and requirements for licensing an 
entombed disposal facility. Should this option replace subpart E for 
purposes of entombment or should a licensee have a choice between 
using Subpart E approach or the entombed facility license approach? 
Should the dose based criteria for the entombed facility license be 
based on subpart E dose limits? If not, what should be the basis for 
those limits.
    A.5.Should the entombed facility option be available only to 
power reactors? If not, under what circumstances should it be 
applied to other than power reactors?
    A.6. Are there other options that the Commission should consider 
in developing an approach to entombment that will provide for its 
viability while maintaining the public health and safety?

B. Technical Feasibility Issues

    Part 20, Subpart E (10 CFR 20.1403), allows release of a site under 
restricted conditions if:
    (a) Institutional controls are in place to limit the dose from 
residual radioactivity to less than 0.25 mSv/yr (25 mrem/yr) TEDE and 
is as low as reasonable achievable (ALARA), and
    (b) the radioactivity present has been reduced so that, if the 
institutional controls were no longer in effect, the dose would be less 
than 1 mSv/yr (100 mrem/yr) TEDE and is ALARA (5 mSv/yr (500 mrem/yr) 
is allowed if ``durable institutional controls'' are used).
    The NRC is considering approval of a license termination plan for 
an entombment based on a site-specific technical evaluation of the 
entombment's ability to fulfill the requirements of 10 CFR part 20, 
subpart E. An analysis prepared for the NRC indicates that the most 
likely way that the entombment engineered barrier might lose its 
effectiveness may be leakage through the barrier. The ability to ensure 
that any release would not exceed authorized levels is a function of 
the design, installation, quality, durability, robustness, etc., of the 
entombed structure, the environment at hand, and the time needed for 
the protective function to be performed. Each case must be evaluated on 
its own merits.

    B.1. To what degree should credit be given to engineered 
barriers for the purposes of dose reduction to meet the license

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termination criteria of 10 CFR part 20, Subpart E?

C. Entombment of Greater Than Class C (GTCC) Waste

    At the time of permanent cessation of power reactor operations, the 
reactor vessel's internals contain some long-lived radioactive material 
that result from neutron activation of these materials near the reactor 
core. One of these radionuclides is Niobium (Nb-94), which has a half 
life of about 20,000 years. If reactor internals with GTCC 
concentrations of Nb-94 had to be disposed of offsite, a special 
facility for their disposal would be required, since they cannot be 
disposed of in LLW facilities. Also removal of the GTCC waste from the 
reactor internals is difficult work and results in exposure to 
occupational workers. In addition, the Low-Level Radioactive Waste 
Policy Amendments Act of 1985 provides that GTCC waste resulting from 
NRC licensed activities may only be disposed of in a facility licensed 
by the NRC.

    C.1. Should material that could be classified as GTCC waste be 
considered in the entombment approach? Are there circumstances under 
which residual radioactivity that could be classified as GTCC be 
allowed to be entombed on site? If so, under what conditions?

D. State Issues

    D.1. Power reactor licensees are exclusively regulated by the NRC 
(under 10 CFR part 50), even in Agreement States. The NRC consults with 
stakeholders, including Agreement and non-Agreement States, about 
regulatory actions under consideration that may impact stakeholders. 
What additional role, if any, should the affected States have in the 
license termination process based on entombment for power reactors? In 
addition should an Agreement State be permitted to issue a license for 
an entombed disposal facility?
    D.2. Under 10 CFR part 20, subpart E, the entombment contains 
material having residual radioactivity and is suitable for license 
termination if the dose criteria are met. However, under other 
statutes, such as the LLW Policy Act, the material might be considered 
to be low level waste. What issues exist for entombment in a State 
where existing State legislation prohibits LLW disposal?
    D.3. Are there other issues for an entombment that impact Low Level 
Waste Compacts?
    D.4. If the entombment disposal facility option does not include 
GTCC waste and the disposal license is issued by an Agreement State, 
what compatibility categories,\2\ as described in NRC's ``Policy 
Statement on Adequacy and Compatibility of Agreement State Programs,'' 
published September 3, 1997 (62 FR 46517), and in NRC's Management 
Directive 5.9, ``Adequacy and Compatibility of Agreement State 
Programs,'' should be assigned?
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    \2\ Compatibility refers t the extent to which Agreement State 
radiation control programs are consistent with NRC's program for the 
regulation of Atomic Energy Act radioactive materials to ensure that 
an adequate and coherent nationwide effort is collectively 
established for regulation of such materials.
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E. Further Information

    E.1. Please provide any other considerations or rule changes that 
the Commission should consider to facilitate license termination based 
on an entombment approach, while maintaining the requisite protection 
of the public health and safety?
    E.2. The NRC is interested in the likelihood that licensees would 
pursue entombment to assist it in formulating its decision regarding 
the entombment options. Please provide your assessment as to the number 
of licensees likely to pursue entombment as a option. Specifically, it 
is requested that reactor licensees indicate their potential interest 
in choosing the entombment option.
    The preliminary views expressed in this document may change in 
light of comments received. If the proposed rule is developed by the 
Commission, there will be another opportunity for additional public 
comment in connection with that proposed rule.

List of Subjects

10 CFR Part 20

    Byproduct material, Criminal penalties, Licensed material, Nuclear 
materials, Nuclear power plants and reactors, Occupational safety and 
health, Packaging and containers, Radiation protection, Reporting and 
recordkeeping requirements, Special nuclear material, Source material, 
Waste treatment and disposal.

10 CFR Part 50

    Antitrust, Classified information, Criminal penalties, Fire 
protection, Intergovernmental relations, Nuclear power plants and 
reactors, Radiation protection, Reactor siting criteria, Reporting and 
recordkeeping requirements.

    The authority citation for this document is: 42 U.S.C. 2201; 42 
U.S.C. 5841.

    Dated at Rockville, Maryland, this 10th day of October, 2001.

    For the Nuclear Regulatory Commission.
J. Samuel Walker,
Acting Secretary of the Commission.
[FR Doc. 01-25958 Filed 10-15-01; 8:45 am]
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