Exelon Generation Company, LLC; Three Mile Island Nuclear Station, Units 1 and 2, 78880-78884 [2020-26767]
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Register on August 26, 2020 (85 FR
52643) for a 30-day public comment
period. The public comment period
closed on September 25, 2020. Two
public comment submissions were
received by the end of the public
comment period. These comment
submissions expressed agreement with
the DG–1351, Revision 1 and
recommended final issuance of the RG.
III. Congressional Review Act
This RG is a rule as defined in the
Congressional Review Act (5 U.S.C.
801–808). However, the Office of
Management and Budget has not found
it to be a major rule as defined in the
Congressional Review Act.
IV. Backfitting, Forward Fitting, and
Issue Finality
RG 1.239 provides guidance on
licensee actions to address
nonconservative technical
specifications. Issuance of RG 1.239
does not constitute backfitting as
defined in 10 CFR 50.109, ‘‘Backfitting,’’
and as described in NRC Management
Directive (MD) 8.4, ‘‘Management of
Backfitting, Forward Fitting, Issue
Finality, and Information Requests;’’
constitute forward fitting as that term is
defined and described in MD 8.4; or
affect the issue finality of any approval
issued under 10 CFR part 52, ‘‘Licenses,
Certificates, and Approvals for Nuclear
Power Plants.’’ As explained in this RG,
applicants and licensees are not
required to comply with the positions
set forth in this RG.
V. Availability of Documents
The documents identified in the
following table are available to
interested persons through ADAMS
under the respective ADAMS Accession
numbers identified in the table.
ADAMS
accession No.
Document
RG 1.239, Licensee Actions to Address Nonconservative Technical Specifications. ........................
DG–1351, Dispositioning of Technical Specifications that are Insufficient to Ensure Plant Safety,
July 2018.
Regulatory Analysis, Draft Regulatory Guide, DG–1351. ...................................................................
DG–1351, Revision 1, Licensee Actions to Address Nonconservative Technical Specifications, August 2020.
NEI 15–03, Revision 2, Licensee Actions to Address Nonconservative Technical Specifications,
September 2017.
Summary of October 17, 2019, Meeting with NEI Regarding DG–1351. ...........................................
Draft NRC Staff Responses to Public Comments on DG-1351. .........................................................
NEI 15–03, Revision 3, Licensee Actions to Address Nonconservative Technical Specifications,
March 2020.
Comment (1) of Brian Mann on Licensee Actions to Address Nonconservative Technical Specifications.
Comment (2) of Timothy Riti on behalf of Nuclear Energy Institute (NEI) on Licensee Actions to
Address Nonconservative Technical Specifications.
Management Directive 8.4, Management of Backfitting, Forward Fitting, Issue Finality, and Information Requests.
Dated: December 2, 2020.
For the Nuclear Regulatory Commission.
Meraj Rahimi,
Chief, Regulatory Guidance and Generic
Issues Branch, Division of Engineering, Office
of Nuclear Regulatory Research.
[FR Doc. 2020–26844 Filed 12–4–20; 8:45 am]
BILLING CODE 7590–01–P
Advisory Committee on Reactor
Safeguards Charter Renewal
Nuclear Regulatory
Commission.
ACTION: Notice of renewal of the charter
of the advisory committee on reactor
safeguards.
AGENCY:
The Advisory Committee on
Reactor Safeguards (ACRS) was
established by the Atomic Energy Act
(AEA) of 1954, as amended. Its purpose
is to provide advice to the Commission
with regard to the hazards of proposed
or existing reactor facilities, to review
each application for a construction
permit or operating license for certain
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SUMMARY:
20:27 Dec 04, 2020
FOR FURTHER INFORMATION CONTACT:
Russell E. Chazell, Office of the
Secretary, NRC, Washington, DC 20555;
telephone: (301) 415–7469 or at
Russell.Chazell@nrc.gov.
The AEA
as amended by Public Law 100–456 also
specifies that the Defense Nuclear Safety
Board may obtain the advice and
recommendations of the ACRS.
Membership on the Committee
includes individuals experienced in
reactor operations, management;
probabilistic risk assessment; analysis of
reactor accident phenomena; design of
nuclear power plant structures, systems
and components; materials science; and
mechanical, civil, and electrical
engineering.
The Nuclear Regulatory Commission
has determined that renewal of the
charter for the ACRS until December 2,
2022, is in the public interest in
connection with the statutory
responsibilities assigned to the ACRS.
This action is being taken in accordance
ML18086A685
ML20142A489
ML17276A642
ML19298B110
ML19267A108
ML20100G899
(Package)
ML20247J650
ML20255A302
ML18093B087
with the Federal Advisory Committee
Act.
Dated: December 2, 2020.
Russell E. Chazell,
Federal Advisory Committee Management
Officer, Office of the Secretary.
[FR Doc. 2020–26804 Filed 12–4–20; 8:45 am]
BILLING CODE 7590–01–P
SUPPLEMENTARY INFORMATION:
NUCLEAR REGULATORY
COMMISSION
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facilities specified in the AEA, and such
other duties as the Commission may
request.
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NUCLEAR REGULATORY
COMMISSION
[Docket Nos. 50–289 and 50–320; NRC–
2020–0217]
Exelon Generation Company, LLC;
Three Mile Island Nuclear Station,
Units 1 and 2
Nuclear Regulatory
Commission.
ACTION: Exemption; issuance.
AGENCY:
The U.S. Nuclear Regulatory
Commission (NRC) has issued
exemptions in response to a request
from Exelon Generation Company, LLC
(Exelon, the licensee) regarding certain
emergency planning (EP) requirements.
The exemptions eliminate the
SUMMARY:
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requirements to maintain an offsite
radiological emergency preparedness
plan and reduce the scope of onsite EP
activities at the Three Mile Island
Nuclear Station, Units 1 and 2 (TMI),
based on the reduced risks of accidents
that could result in an offsite
radiological release at a
decommissioning nuclear power
reactor.
For the Nuclear Regulatory Commission.
Bruce Watson,
Chief, Reactor Decommissioning Branch,
Division of Decommissioning, Uranium
Recovery, and Waste Programs, Office of
Nuclear Material Safety and Safeguards.
The exemptions were issued on
December 1, 2020.
Exelon Generation Company, LLC
DATES:
Please refer to Docket ID
NRC–2020–0217 when contacting the
NRC about the availability of
information regarding this document.
You may obtain publicly available
information related to this document
using any of the following methods:
• Federal Rulemaking website: Go to
https://www.regulations.gov and search
for Docket ID NRC–2020–0217. Address
questions about Docket IDs to Jennifer
Borges; telephone: 301–287–9127;
email: Jennifer.Borges@nrc.gov. For
technical questions, contact the
individual listed in the FOR FURTHER
INFORMATION CONTACT section of this
document.
• NRC’s Agencywide Documents
Access and Management System
(ADAMS): You may obtain publicly
available documents online in the
ADAMS Public Documents collection at
https://www.nrc.gov/reading-rm/
adams.html. To begin the search, select
‘‘Begin Web-based ADAMS Search.’’ For
problems with ADAMS, please contact
the NRC’s Public Document Room (PDR)
reference staff at 1–800–397–4209, 301–
415–4737, or by email to pdr.resource@
nrc.gov. The ADAMS accession number
for each document referenced (if it is
available in ADAMS) is provided the
first time that it is mentioned in this
document.
• Attention: The PDR, where you may
examine and order copies of public
documents is currently closed. You may
submit your request to the PDR via
email at PDR.Resource@nrc.gov or call
1–800–397–4209 between 8:00 a.m. and
4:00 p.m. (EST), Monday through
Friday, except Federal holidays.
ADDRESSES:
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FOR FURTHER INFORMATION CONTACT:
Theodore Smith, Office of Nuclear
Material Safety and Safeguards, U.S.
Nuclear Regulatory Commission,
Washington DC 20555–0001; telephone:
301–415–6721; email: Theodore.Smith@
nrc.gov.
SUPPLEMENTARY INFORMATION:
The text of
the exemptions are attached.
Dated: December 1, 2020.
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Attachment—Exemption
Nuclear Regulatory Commission
[Docket Nos. 50–289 and 50–320]
Three Mile Island Nuclear Station,
Units 1 and 2 Exemptions
I. Background
Exelon Generation Company, LLC
(Exelon, the licensee) is the holder of
U.S. Nuclear Regulatory Commission
(NRC, the Commission) Renewed
Facility Operating License No. DPR–50
for Three Mile Island Nuclear Station,
Unit 1 (TMI–1). Three Mile Island
Nuclear Station, Unit 2 (TMI–2) has a
possession-only license and is currently
maintained in accordance with the
NRC-approved SAFSTOR condition
known as post-defueling monitored
storage. Exelon maintains the
emergency planning responsibilities for
TMI–2, which is owned by GPU
Nuclear, Inc., through a service
agreement. These licenses are subject to
the rules, regulations, and orders of the
NRC. The licensed facilities consist of
permanently shutdown pressurizedwater reactors (PWR) located in
Dauphin County, Pennsylvania.
By letter dated June 20, 2017
(Agencywide Documents Access and
Management System (ADAMS)
Accession No. ML17171A151), Exelon
submitted a certification to the NRC that
it would permanently cease power
operations at TMI–1 on or about
September 30, 2019. On September 20,
2019, Exelon permanently ceased power
operations at TMI–1. By letter dated
September 26, 2019 (ADAMS Accession
No. ML19269E480), Exelon certified the
permanent removal of fuel from the
TMI–1 reactor vessel. In accordance
with paragraph 50.82(a)(2) of Title 10 of
the Code of Federal Regulations (10
CFR), upon the docketing of these
certifications, the license for TMI–1 no
longer authorizes operation of the
reactor or emplacement or retention of
fuel into the reactor vessel. The facility
is still authorized to possess and store
irradiated (i.e., spent) nuclear fuel.
Spent fuel is currently stored onsite in
the TMI–1 spent fuel pool (SFP). A dry
cask independent spent fuel storage
installation is under construction to
store the TMI–1 spent fuel. Since the
license for TMI–2 had previously been
modified to allow possession but not
operation of the facility, the
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certifications of permanent cessation of
operations and permanent removal of
fuel are, by rule, deemed to have been
submitted for TMI–2. Spent fuel for
TMI–2 has already been removed from
the site, though residual contamination
and radiological materials exist.
During normal power reactor
operations, the forced flow of water
through the reactor coolant system
removes heat generated by the reactor.
The reactor coolant system, operating at
high temperatures and pressures,
transfers this heat through the steam
generator tubes converting nonradioactive feedwater to steam, which
then flows to the main turbine generator
to produce electricity. Many of the
accident scenarios postulated in the
updated safety analysis reports for
operating power reactors involve
failures or malfunctions of systems,
which could affect the fuel in the
reactor core and, in the most severe
postulated accidents, would involve the
release of large quantities of fission
products. With the permanent cessation
of operations and the permanent
removal of the fuel from the reactor
vessels at TMI, such accidents are no
longer possible. The reactor, reactor
coolant system, and supporting systems
are no longer in operation and have no
function related to the storage of the
spent fuel. Therefore, emergency
planning (EP) provisions for postulated
accidents involving failure or
malfunction of the reactor, reactor
coolant system, or supporting systems
are no longer applicable.
The EP requirements of 10 CFR 50.47,
‘‘Emergency plans,’’ and Appendix E to
10 CFR part 50, ‘‘Emergency Planning
and Preparedness for Production and
Utilization Facilities,’’ continue to apply
to nuclear power reactors that have
permanently ceased operation and have
permanently removed all fuel from the
reactor vessel. There are no explicit
regulatory provisions distinguishing EP
requirements for a power reactor that is
permanently shut down and defueled
from those for a reactor that is
authorized to operate. To reduce or
eliminate EP requirements that are no
longer necessary due to the
decommissioning status of the facility,
Exelon must obtain exemptions from
those EP regulations. Only then can
Exelon modify the TMI emergency plan
to reflect the reduced risk associated
with the permanently shutdown and
defueled condition of TMI.
II. Request/Action
By letter dated July 1, 2019 (ADAMS
Accession No. ML19182A104), Exelon
requested exemptions from certain EP
requirements in 10 CFR part 50 for TMI.
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Specifically, Exelon requested
exemptions from certain planning
standards in 10 CFR 50.47(b) regarding
onsite and offsite radiological
emergency preparedness plans for
nuclear power reactors; from certain
requirements in 10 CFR 50.47(c)(2) for
the establishment of plume exposure
and ingestion pathway emergency
planning zones for nuclear power
reactors; and from certain requirements
in 10 CFR part 50, Appendix E, Section
IV, which establish the elements that
make up the content of emergency
plans. In letters dated October 9, 2019,
and December 10, 2019 (ADAMS
Accession Nos. ML19282C285 and
ML19344C115, respectively), Exelon
provided supplemental information and
responses to the NRC staff’s requests for
additional information concerning the
proposed exemptions.
The information provided by Exelon
included justifications for each
exemption requested. The exemptions
requested by Exelon would eliminate
the requirements to maintain formal
offsite radiological emergency
preparedness plans reviewed by the
Federal Emergency Management Agency
(FEMA) under the requirements of 44
CFR part 350 and would reduce the
scope of onsite EP activities at TMI. The
licensee stated that the application of all
of the standards and requirements in 10
CFR 50.47(b), 10 CFR 50.47(c), and 10
CFR part 50, Appendix E is not needed
for adequate emergency response
capability, based on the substantially
lower onsite and offsite radiological
consequences of accidents still possible
at the permanently shutdown and
defueled facility, as compared to an
operating facility. If offsite protective
actions were needed for a highly
unlikely beyond-design-basis accident
that could challenge the safe storage of
spent fuel at TMI, provisions exist for
offsite agencies to take protective
actions using a comprehensive
emergency management plan (CEMP)
under the National Preparedness System
to protect the health and safety of the
public. A CEMP in this context, also
referred to as an emergency operations
plan, is addressed in FEMA’s
Comprehensive Preparedness Guide
101, ‘‘Developing and Maintaining
Emergency Operations Plans,’’ which is
publicly available at https://
www.fema.gov/pdf/about/divisions/
npd/CPG_101_V2.pdf. Comprehensive
Preparedness Guide 101 is the
foundation for State, territorial, Tribal,
and local EP in the United States. It
promotes a common understanding of
the fundamentals of risk-informed
planning and decisionmaking and helps
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planners at all levels of government in
their efforts to develop and maintain
viable, all-hazards, all-threats
emergency plans. An emergency
operations plan is flexible enough for
use in all emergencies. It describes how
people and property will be protected;
details who is responsible for carrying
out specific actions; identifies the
personnel, equipment, facilities,
supplies and other resources available;
and outlines how all actions will be
coordinated. A CEMP is often referred to
as a synonym for ‘‘all-hazards
planning.’’
III. Discussion
In accordance with 10 CFR 50.12,
‘‘Specific exemptions,’’ the Commission
may, upon application by any interested
person or upon its own initiative, grant
exemptions from the requirements of 10
CFR part 50 when: (1) The exemptions
are authorized by law, will not present
an undue risk to public health and
safety, and are consistent with the
common defense and security; and (2)
any of the special circumstances listed
in 10 CFR 50.12(a)(2) are present. These
special circumstances include, among
other things, that the application of the
regulation in the particular
circumstances would not serve the
underlying purpose of the rule or is not
necessary to achieve the underlying
purpose of the rule.
As noted previously, the EP
regulations contained in 10 CFR
50.47(b) and Appendix E to 10 CFR part
50 apply to both operating and
shutdown power reactors. The NRC has
consistently acknowledged that the risk
of an offsite radiological release at a
power reactor that has permanently
ceased operations and permanently
removed fuel from the reactor vessel is
significantly lower, and the types of
possible accidents are significantly
fewer, than at an operating power
reactor. However, the EP regulations do
not recognize that once a power reactor
permanently ceases operation, the risk
of a large radiological release from
credible emergency accident scenarios
is significantly reduced. The reduced
risk for any significant offsite
radiological release is based on two
factors. One factor is the elimination of
accidents applicable only to an
operating power reactor, resulting in
fewer credible accident scenarios. The
second factor is the reduced short-lived
radionuclide inventory and decay heat
production due to radioactive decay.
Due to the permanently defueled status
of the reactor, no new spent fuel will be
added to the SFP and the radionuclides
in the current spent fuel will continue
to decay as the spent fuel ages. The
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spent fuel will produce less heat due to
radioactive decay, increasing the
available time to mitigate a loss of water
inventory from the SFP. The NRC’s
NUREG/CR–6451, ‘‘A Safety and
Regulatory Assessment of Generic BWR
[Boiling Water Reactor] and PWR
Permanently Shutdown Nuclear Power
Plants,’’ dated August 1997 (ADAMS
Accession No. ML082260098), and the
NRC’s NUREG–1738, ‘‘Technical Study
of Spent Fuel Pool Accident Risk at
Decommissioning Nuclear Power
Plants,’’ dated February 2001 (ADAMS
Accession No. ML010430066),
confirmed that for permanently
shutdown and defueled power reactors
that are bounded by the assumptions
and conditions in the report, the risk of
offsite radiological release is
significantly less than for an operating
power reactor.
In the past, EP exemptions similar to
those requested for TMI have been
granted to permanently shutdown and
defueled power reactor licensees.
However, the exemptions did not
relieve the licensees of all EP
requirements. Rather, the exemptions
allowed the licensees to modify their
emergency plans commensurate with
the credible site-specific risks that were
consistent with a permanently
shutdown and defueled status.
Specifically, the NRC’s approval of
these prior exemptions was based on the
licensee’s demonstration that: (1) The
radiological consequences of designbasis accidents would not exceed the
limits of the U.S. Environmental
Protection Agency (EPA) early phase
Protective Action Guides (PAGs) of one
roentgen equivalent man at the
exclusion area boundary; and (2) in the
highly unlikely event of a beyonddesign-basis accident resulting in a loss
of all modes of heat transfer from the
fuel stored in the SFP, there is sufficient
time to initiate appropriate mitigating
actions, and if needed, for offsite
authorities to implement offsite
protective actions using a CEMP
approach to protect the health and
safety of the public.
With respect to design-basis accidents
at TMI, the licensee provided an
analysis demonstrating that following
permanent cessation of power
operations at TMI–1, the radiological
consequences of the remaining designbasis accidents with potential for offsite
radiological release (a fuel handling
accident in the Fuel Handling Building,
where the SFP is located for TMI–1, and
a fire in the Reactor Building with the
Reactor Building Purge System in
operation for TMI–2) will not exceed the
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limits of the EPA PAGs at the exclusion
area boundary.
With respect to beyond-design-basis
accidents at TMI, the licensee analyzed
a drain down of the SFP water that
would effectively impede any decay
heat removal. The analysis demonstrates
that at 488 days (approximately 16
months) after permanent cessation of
power operations, there would be 10
hours after the assemblies have been
uncovered until the limiting fuel
assembly (for decay heat and adiabatic
heat-up analysis) reaches 900 degrees
Celsius (°C), the temperature used to
assess the potential onset of fission
product release. The analysis
conservatively assumed that the heat-up
time starts when the SFP has been
completely drained, although it is likely
that site personnel will start to respond
to an incident when drain down starts.
The analysis also does not consider the
period of time from the initiating event
causing loss of SFP water inventory
until cooling is lost.
The NRC reviewed the licensee’s
justification for the requested
exemptions against the criteria in 10
CFR 50.12(a) and determined, as
described below, that the criteria in 10
CFR 50.12(a) will be met, and that the
exemptions should be granted 488 days
after TMI–1 has permanently ceased
power operations. An assessment of the
Exelon EP exemptions is described in
SECY–20–0041, ‘‘Request by Exelon
Generation Company, LLC for
Exemptions from Certain Emergency
Planning Requirements for the Three
Mile Island Nuclear Station,’’ dated May
5, 2020 (ADAMS Package Accession No.
ML19311C762). The Commission
approved the NRC staff’s
recommendation to grant the
exemptions in the staff requirements
memorandum to SECY–20–0041, dated
July 27, 2020 (ADAMS Accession No.
ML20209A439). Descriptions of the
specific exemptions requested by
Exelon and the NRC staff’s basis for
granting each exemption are provided in
SECY–20–0041. The NRC staff’s
detailed review and technical basis for
the approval of the specific EP
exemptions requested by Exelon are
provided in the NRC staff’s safety
evaluation associated with this
exemption (ADAMS Accession No.
ML19311C762).
A. The Exemption Is Authorized by Law
The licensee has proposed
exemptions from certain EP
requirements in 10 CFR 50.47(b), 10
CFR 50.47(c)(2), and 10 CFR part 50,
Appendix E, Section IV, that would
allow Exelon to revise the TMI
Emergency Plan to reflect the
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18:32 Dec 04, 2020
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permanently shutdown and defueled
condition of the facility. As stated
above, in accordance with 10 CFR 50.12,
the Commission may, upon application
by any interested person or upon its
own initiative, grant exemptions from
the requirements of 10 CFR part 50. The
NRC staff has determined that granting
of the licensee’s proposed exemptions
will not result in a violation of the
Atomic Energy Act of 1954, as amended,
or the NRC’s regulations. Therefore, the
exemptions are authorized by law.
B. The Exemption Presents No Undue
Risk to Public Health and Safety
As stated previously, Exelon provided
an analysis that shows that the
radiological consequences of designbasis accidents will not exceed the
limits of the EPA early phase PAGs at
the exclusion area boundary. Therefore,
formal offsite radiological emergency
preparedness plans required under 10
CFR part 50 will no longer be needed for
protection of the public beyond the
exclusion area boundary, based on the
radiological consequences of designbasis accidents still possible at TMI 488
days after TMI–1 has permanently
ceased power operations.
Although highly unlikely, there is one
postulated beyond-design-basis accident
that might result in significant offsite
radiological releases. However, NUREG–
1738 confirms that the risk of beyonddesign-basis accidents is greatly reduced
at permanently shutdown and defueled
reactors. The NRC staff’s analyses in
NUREG–1738 conclude that the event
sequences important to risk at
permanently shutdown and defueled
power reactors are limited to large
earthquakes and cask drop events. For
EP assessments, this is an important
difference relative to operating power
reactors, where typically a large number
of different sequences make significant
contributions to risk. As described in
NUREG–1738, relaxation of offsite EP
requirements in 10 CFR part 50 beyond
a few months after shutdown resulted in
only a small change in risk. The report
further concludes that the change in risk
due to relaxation of offsite EP
requirements is small because the
overall risk is low, and because even
under current EP requirements for
operating power reactors, EP was judged
to have marginal impact on evacuation
effectiveness for the severe earthquakes
that dominate SFP risk. All other
sequences including cask drops (for
which offsite radiological emergency
preparedness plans are expected to be
more effective) are too low in likelihood
to have a significant impact on risk.
Therefore, granting exemptions to
eliminate the requirements of 10 CFR
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part 50 to maintain offsite radiological
emergency preparedness plans and to
reduce the scope of onsite EP activities
will not present an undue risk to the
public health and safety.
C. The Exemption Is Consistent With the
Common Defense and Security
The requested exemptions only
involve EP requirements under 10 CFR
part 50 and will allow Exelon to revise
the TMI Emergency Plan to reflect the
permanently shutdown and defueled
condition of the facility. Physical
security measures at TMI are not
affected by the requested EP
exemptions. The discontinuation of
formal offsite radiological emergency
preparedness plans and the reduction in
scope of the onsite EP activities at TMI
will not adversely affect Exelon’s ability
to physically secure the site or protect
special nuclear material. Therefore, the
proposed exemptions are consistent
with common defense and security.
D. Special Circumstances
Special circumstances, in accordance
with 10 CFR 50.12(a)(2)(ii), are present
whenever application of the regulation
in the particular circumstances is not
necessary to achieve the underlying
purpose of the rule. The underlying
purpose of 10 CFR 50.47(b), 10 CFR
50.47(c)(2), and 10 CFR part 50,
Appendix E, Section IV, is to provide
reasonable assurance that adequate
protective measures can and will be
taken in the event of a radiological
emergency, to establish plume exposure
and ingestion pathway emergency
planning zones for nuclear power
plants, and to ensure that licensees
maintain effective offsite and onsite
radiological emergency preparedness
plans. The standards and requirements
in these regulations were developed by
considering the risks associated with
operation of a power reactor at its
licensed full-power level. These risks
include the potential for a reactor
accident with offsite radiological dose
consequences.
As discussed previously in Section III,
because TMI will be permanently shut
down and defueled, there will no longer
be a risk of a significant offsite
radiological release from a design-basis
accident exceeding EPA early phase
PAGs at the exclusion area boundary
and the risk of a significant offsite
radiological release from a beyonddesign-basis accident is greatly reduced
when compared to an operating power
reactor. The NRC staff has confirmed the
reduced risks at TMI by comparing the
generic risk assumptions in the analyses
in NUREG–1738 to site-specific
conditions at TMI and determined that
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the risk values in NUREG–1738 bound
the risks presented at TMI. As indicated
by the results of the research conducted
for NUREG–1738, and more recently for
NUREG–2161, ‘‘Consequence Study of a
Beyond-Design-Basis Earthquake
Affecting the Spent Fuel Pool for a U.S.
Mark I Boiling Water Reactor,’’ dated
September 2014 (ADAMS Accession No.
ML14255A365), while other
consequences can be extensive,
accidents from SFPs with significant
decay time have little potential to cause
offsite early fatalities, even if the formal
offsite radiological EP requirements
were relaxed. The licensee’s analysis of
a beyond-design-basis accident
involving a complete loss of SFP water
inventory, based on an adiabatic heat-up
analysis of the limiting fuel assembly for
decay heat, shows that 488 days after
permanent cessation of power
operations at TMI–1, the time for the
limiting fuel assembly to reach 900 °C
is at least 10 hours after the assemblies
have been uncovered assuming a loss of
all cooling means.
The only analyzed beyond-designbasis accident scenario that progresses
to a condition where a significant offsite
release might occur, involves the highly
unlikely event where the SFP drains in
such a way that all modes of cooling or
heat transfer are assumed to be
unavailable, which is referred to as an
adiabatic heat-up of the spent fuel. The
licensee’s analysis of this beyonddesign-basis accident shows that 488
days after permanent cessation of power
operations at TMI–1, at least 10 hours
would be available between the time
that all cooling means are lost to the fuel
(at which time adiabatic heat-up is
conservatively assumed to begin), until
the fuel cladding reaches a temperature
of 1652 degrees Fahrenheit (900 °C),
which is the temperature associated
with rapid cladding oxidation and the
potential for a significant radiological
release. This analysis conservatively
does not include the period of time from
the initiating event causing a loss of SFP
water inventory until all cooling means
are lost.
The NRC staff has verified Exelon’s
analyses and its calculations. The
analyses provide reasonable assurance
that in granting the requested
exemptions to Exelon, there is no
design-basis accident that will result in
an offsite radiological release exceeding
the EPA early phase PAGs at the
exclusion area boundary. In the highly
unlikely event of a beyond-design-basis
accident affecting the SFP that results in
a complete loss of heat removal via all
modes of heat transfer, there will be
over 10 hours available before an offsite
release might occur and, therefore, at
VerDate Sep<11>2014
18:32 Dec 04, 2020
Jkt 253001
least 10 hours to initiate appropriate
mitigating actions to restore a means of
heat removal to the spent fuel. If a
radiological release were projected to
occur under this highly unlikely
scenario, a minimum of 10 hours is
considered sufficient time for offsite
authorities to implement protective
actions using a CEMP approach to
protect the health and safety of the
public.
Exemptions from the offsite EP
requirements in 10 CFR part 50 have
previously been approved by the NRC
when the site-specific analyses show
that at least 10 hours is available
following a loss of SFP coolant
inventory accident with no air cooling
(or other methods of removing decay
heat) until cladding of the hottest fuel
assembly reaches the rapid oxidation
temperature. The NRC staff concluded
in its previously granted exemptions, as
it does with Exelon’s requested EP
exemptions, that if a minimum of 10
hours is available to initiate mitigative
actions consistent with plant conditions
or, if needed, for offsite authorities to
implement protective actions using a
CEMP approach, then formal offsite
radiological emergency preparedness
plans, required under 10 CFR part 50,
are not necessary at permanently
shutdown and defueled facilities.
Additionally, TMI committed to
maintaining SFP makeup strategies in
its application. The multiple strategies
for providing makeup to the SFP
include: using existing plant systems for
inventory makeup; an internal strategy
that relies on the fire protection system
with redundant pumps (one dieseldriven and one electric motor-driven);
and an off-site fire truck that can take
suction from the Susquehanna River.
These strategies will continue to be
required as condition 2.c.(17),
‘‘Mitigation Strategy License
Condition,’’ of the TMI–1 Renewed
Facility Operating License. Considering
the very low probability of beyonddesign-basis accidents affecting the SFP,
these diverse strategies provide multiple
methods to obtain additional makeup or
spray to the SFP before the onset of any
postulated offsite radiological release.
For all of the reasons stated above, the
NRC staff finds that the licensee’s
requested exemptions meet the
underlying purpose of all of the
standards in 10 CFR 50.47(b), and
requirements in 10 CFR 50.47(c)(2) and
10 CFR part 50, Appendix E, and satisfy
the special circumstances provision in
10 CFR 50.12(a)(2)(ii) in view of the
greatly reduced risk of offsite
radiological consequences associated
with the permanently shutdown and
defueled state of the TMI facility 488
PO 00000
Frm 00064
Fmt 4703
Sfmt 4703
days after permanent cessation of power
operations of TMI–1.
The NRC staff has concluded that the
exemptions being granted by this action
will maintain an acceptable level of
emergency preparedness at TMI and, if
needed, that there is reasonable
assurance that adequate offsite
protective measures can and will be
taken by State and local government
agencies using a CEMP approach in the
highly unlikely event of a radiological
emergency at TMI. Since the underlying
purpose of the rules, as exempted,
would continue to be achieved, even
with the elimination of the requirements
under 10 CFR part 50 to maintain formal
offsite radiological emergency
preparedness plans and the reduction in
the scope of the onsite emergency
planning activities at TMI, the special
circumstances required by 10 CFR
50.12(a)(2)(ii) exist.
E. Environmental Considerations
In accordance with 10 CFR 51.31(a),
the Commission has determined that the
granting of this exemption will not have
a significant effect on the quality of the
human environment as discussed in the
NRC staff’s Finding of No Significant
Impact and associated Environmental
Assessment published in the Federal
Register on September 22, 2020 (85 FR
59565).
IV. Conclusions
Accordingly, the Commission has
determined that, pursuant to 10 CFR
50.12, Exelon’s request for exemptions
from certain EP requirements in 10 CFR
50.47(b), 10 CFR 50.47(c)(2), and 10 CFR
part 50, Appendix E, Section IV, and as
summarized in Enclosure 2 to SECY–
20–0041, are authorized by law, will not
present an undue risk to the public
health and safety, and are consistent
with the common defense and security.
Also, special circumstances are present.
Therefore, the Commission hereby
grants Exelon’s exemptions from certain
EP requirements in 10 CFR 50.47(b), 10
CFR 50.47(c)(2), and 10 CFR part 50,
Appendix E, Section IV, as discussed
and evaluated in detail in the NRC
staff’s safety evaluation associated with
this exemption. The exemptions are
effective as of 488 days after permanent
cessation of power operations of TMI–
1.
Dated: December 1, 2020.
For the Nuclear Regulatory Commission.
Patricia K. Holahan, Director,
Division of Decommissioning, Uranium
Recovery, and Waste Programs, Office of
Nuclear Material Safety and Safeguards.
[FR Doc. 2020–26767 Filed 12–4–20; 8:45 am]
BILLING CODE 7590–01–P
E:\FR\FM\07DEN1.SGM
07DEN1
Agencies
[Federal Register Volume 85, Number 235 (Monday, December 7, 2020)]
[Notices]
[Pages 78880-78884]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-26767]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-289 and 50-320; NRC-2020-0217]
Exelon Generation Company, LLC; Three Mile Island Nuclear
Station, Units 1 and 2
AGENCY: Nuclear Regulatory Commission.
ACTION: Exemption; issuance.
-----------------------------------------------------------------------
SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has issued
exemptions in response to a request from Exelon Generation Company, LLC
(Exelon, the licensee) regarding certain emergency planning (EP)
requirements. The exemptions eliminate the
[[Page 78881]]
requirements to maintain an offsite radiological emergency preparedness
plan and reduce the scope of onsite EP activities at the Three Mile
Island Nuclear Station, Units 1 and 2 (TMI), based on the reduced risks
of accidents that could result in an offsite radiological release at a
decommissioning nuclear power reactor.
DATES: The exemptions were issued on December 1, 2020.
ADDRESSES: Please refer to Docket ID NRC-2020-0217 when contacting the
NRC about the availability of information regarding this document. You
may obtain publicly available information related to this document
using any of the following methods:
Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2020-0217. Address
questions about Docket IDs to Jennifer Borges; telephone: 301-287-9127;
email: [email protected]. For technical questions, contact the
individual listed in the FOR FURTHER INFORMATION CONTACT section of
this document.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly available documents online in the
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS
Search.'' For problems with ADAMS, please contact the NRC's Public
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or
by email to [email protected]. The ADAMS accession number for each
document referenced (if it is available in ADAMS) is provided the first
time that it is mentioned in this document.
Attention: The PDR, where you may examine and order copies
of public documents is currently closed. You may submit your request to
the PDR via email at [email protected] or call 1-800-397-4209
between 8:00 a.m. and 4:00 p.m. (EST), Monday through Friday, except
Federal holidays.
FOR FURTHER INFORMATION CONTACT: Theodore Smith, Office of Nuclear
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission,
Washington DC 20555-0001; telephone: 301-415-6721; email:
[email protected].
SUPPLEMENTARY INFORMATION: The text of the exemptions are attached.
Dated: December 1, 2020.
For the Nuclear Regulatory Commission.
Bruce Watson,
Chief, Reactor Decommissioning Branch, Division of Decommissioning,
Uranium Recovery, and Waste Programs, Office of Nuclear Material Safety
and Safeguards.
Attachment--Exemption
Nuclear Regulatory Commission
[Docket Nos. 50-289 and 50-320]
Exelon Generation Company, LLC
Three Mile Island Nuclear Station, Units 1 and 2 Exemptions
I. Background
Exelon Generation Company, LLC (Exelon, the licensee) is the holder
of U.S. Nuclear Regulatory Commission (NRC, the Commission) Renewed
Facility Operating License No. DPR-50 for Three Mile Island Nuclear
Station, Unit 1 (TMI-1). Three Mile Island Nuclear Station, Unit 2
(TMI-2) has a possession-only license and is currently maintained in
accordance with the NRC-approved SAFSTOR condition known as post-
defueling monitored storage. Exelon maintains the emergency planning
responsibilities for TMI-2, which is owned by GPU Nuclear, Inc.,
through a service agreement. These licenses are subject to the rules,
regulations, and orders of the NRC. The licensed facilities consist of
permanently shutdown pressurized-water reactors (PWR) located in
Dauphin County, Pennsylvania.
By letter dated June 20, 2017 (Agencywide Documents Access and
Management System (ADAMS) Accession No. ML17171A151), Exelon submitted
a certification to the NRC that it would permanently cease power
operations at TMI-1 on or about September 30, 2019. On September 20,
2019, Exelon permanently ceased power operations at TMI-1. By letter
dated September 26, 2019 (ADAMS Accession No. ML19269E480), Exelon
certified the permanent removal of fuel from the TMI-1 reactor vessel.
In accordance with paragraph 50.82(a)(2) of Title 10 of the Code of
Federal Regulations (10 CFR), upon the docketing of these
certifications, the license for TMI-1 no longer authorizes operation of
the reactor or emplacement or retention of fuel into the reactor
vessel. The facility is still authorized to possess and store
irradiated (i.e., spent) nuclear fuel. Spent fuel is currently stored
onsite in the TMI-1 spent fuel pool (SFP). A dry cask independent spent
fuel storage installation is under construction to store the TMI-1
spent fuel. Since the license for TMI-2 had previously been modified to
allow possession but not operation of the facility, the certifications
of permanent cessation of operations and permanent removal of fuel are,
by rule, deemed to have been submitted for TMI-2. Spent fuel for TMI-2
has already been removed from the site, though residual contamination
and radiological materials exist.
During normal power reactor operations, the forced flow of water
through the reactor coolant system removes heat generated by the
reactor. The reactor coolant system, operating at high temperatures and
pressures, transfers this heat through the steam generator tubes
converting non-radioactive feedwater to steam, which then flows to the
main turbine generator to produce electricity. Many of the accident
scenarios postulated in the updated safety analysis reports for
operating power reactors involve failures or malfunctions of systems,
which could affect the fuel in the reactor core and, in the most severe
postulated accidents, would involve the release of large quantities of
fission products. With the permanent cessation of operations and the
permanent removal of the fuel from the reactor vessels at TMI, such
accidents are no longer possible. The reactor, reactor coolant system,
and supporting systems are no longer in operation and have no function
related to the storage of the spent fuel. Therefore, emergency planning
(EP) provisions for postulated accidents involving failure or
malfunction of the reactor, reactor coolant system, or supporting
systems are no longer applicable.
The EP requirements of 10 CFR 50.47, ``Emergency plans,'' and
Appendix E to 10 CFR part 50, ``Emergency Planning and Preparedness for
Production and Utilization Facilities,'' continue to apply to nuclear
power reactors that have permanently ceased operation and have
permanently removed all fuel from the reactor vessel. There are no
explicit regulatory provisions distinguishing EP requirements for a
power reactor that is permanently shut down and defueled from those for
a reactor that is authorized to operate. To reduce or eliminate EP
requirements that are no longer necessary due to the decommissioning
status of the facility, Exelon must obtain exemptions from those EP
regulations. Only then can Exelon modify the TMI emergency plan to
reflect the reduced risk associated with the permanently shutdown and
defueled condition of TMI.
II. Request/Action
By letter dated July 1, 2019 (ADAMS Accession No. ML19182A104),
Exelon requested exemptions from certain EP requirements in 10 CFR part
50 for TMI.
[[Page 78882]]
Specifically, Exelon requested exemptions from certain planning
standards in 10 CFR 50.47(b) regarding onsite and offsite radiological
emergency preparedness plans for nuclear power reactors; from certain
requirements in 10 CFR 50.47(c)(2) for the establishment of plume
exposure and ingestion pathway emergency planning zones for nuclear
power reactors; and from certain requirements in 10 CFR part 50,
Appendix E, Section IV, which establish the elements that make up the
content of emergency plans. In letters dated October 9, 2019, and
December 10, 2019 (ADAMS Accession Nos. ML19282C285 and ML19344C115,
respectively), Exelon provided supplemental information and responses
to the NRC staff's requests for additional information concerning the
proposed exemptions.
The information provided by Exelon included justifications for each
exemption requested. The exemptions requested by Exelon would eliminate
the requirements to maintain formal offsite radiological emergency
preparedness plans reviewed by the Federal Emergency Management Agency
(FEMA) under the requirements of 44 CFR part 350 and would reduce the
scope of onsite EP activities at TMI. The licensee stated that the
application of all of the standards and requirements in 10 CFR
50.47(b), 10 CFR 50.47(c), and 10 CFR part 50, Appendix E is not needed
for adequate emergency response capability, based on the substantially
lower onsite and offsite radiological consequences of accidents still
possible at the permanently shutdown and defueled facility, as compared
to an operating facility. If offsite protective actions were needed for
a highly unlikely beyond-design-basis accident that could challenge the
safe storage of spent fuel at TMI, provisions exist for offsite
agencies to take protective actions using a comprehensive emergency
management plan (CEMP) under the National Preparedness System to
protect the health and safety of the public. A CEMP in this context,
also referred to as an emergency operations plan, is addressed in
FEMA's Comprehensive Preparedness Guide 101, ``Developing and
Maintaining Emergency Operations Plans,'' which is publicly available
at https://www.fema.gov/pdf/about/divisions/npd/CPG_101_V2.pdf.
Comprehensive Preparedness Guide 101 is the foundation for State,
territorial, Tribal, and local EP in the United States. It promotes a
common understanding of the fundamentals of risk-informed planning and
decisionmaking and helps planners at all levels of government in their
efforts to develop and maintain viable, all-hazards, all-threats
emergency plans. An emergency operations plan is flexible enough for
use in all emergencies. It describes how people and property will be
protected; details who is responsible for carrying out specific
actions; identifies the personnel, equipment, facilities, supplies and
other resources available; and outlines how all actions will be
coordinated. A CEMP is often referred to as a synonym for ``all-hazards
planning.''
III. Discussion
In accordance with 10 CFR 50.12, ``Specific exemptions,'' the
Commission may, upon application by any interested person or upon its
own initiative, grant exemptions from the requirements of 10 CFR part
50 when: (1) The exemptions are authorized by law, will not present an
undue risk to public health and safety, and are consistent with the
common defense and security; and (2) any of the special circumstances
listed in 10 CFR 50.12(a)(2) are present. These special circumstances
include, among other things, that the application of the regulation in
the particular circumstances would not serve the underlying purpose of
the rule or is not necessary to achieve the underlying purpose of the
rule.
As noted previously, the EP regulations contained in 10 CFR
50.47(b) and Appendix E to 10 CFR part 50 apply to both operating and
shutdown power reactors. The NRC has consistently acknowledged that the
risk of an offsite radiological release at a power reactor that has
permanently ceased operations and permanently removed fuel from the
reactor vessel is significantly lower, and the types of possible
accidents are significantly fewer, than at an operating power reactor.
However, the EP regulations do not recognize that once a power reactor
permanently ceases operation, the risk of a large radiological release
from credible emergency accident scenarios is significantly reduced.
The reduced risk for any significant offsite radiological release is
based on two factors. One factor is the elimination of accidents
applicable only to an operating power reactor, resulting in fewer
credible accident scenarios. The second factor is the reduced short-
lived radionuclide inventory and decay heat production due to
radioactive decay. Due to the permanently defueled status of the
reactor, no new spent fuel will be added to the SFP and the
radionuclides in the current spent fuel will continue to decay as the
spent fuel ages. The spent fuel will produce less heat due to
radioactive decay, increasing the available time to mitigate a loss of
water inventory from the SFP. The NRC's NUREG/CR-6451, ``A Safety and
Regulatory Assessment of Generic BWR [Boiling Water Reactor] and PWR
Permanently Shutdown Nuclear Power Plants,'' dated August 1997 (ADAMS
Accession No. ML082260098), and the NRC's NUREG-1738, ``Technical Study
of Spent Fuel Pool Accident Risk at Decommissioning Nuclear Power
Plants,'' dated February 2001 (ADAMS Accession No. ML010430066),
confirmed that for permanently shutdown and defueled power reactors
that are bounded by the assumptions and conditions in the report, the
risk of offsite radiological release is significantly less than for an
operating power reactor.
In the past, EP exemptions similar to those requested for TMI have
been granted to permanently shutdown and defueled power reactor
licensees. However, the exemptions did not relieve the licensees of all
EP requirements. Rather, the exemptions allowed the licensees to modify
their emergency plans commensurate with the credible site-specific
risks that were consistent with a permanently shutdown and defueled
status. Specifically, the NRC's approval of these prior exemptions was
based on the licensee's demonstration that: (1) The radiological
consequences of design-basis accidents would not exceed the limits of
the U.S. Environmental Protection Agency (EPA) early phase Protective
Action Guides (PAGs) of one roentgen equivalent man at the exclusion
area boundary; and (2) in the highly unlikely event of a beyond-design-
basis accident resulting in a loss of all modes of heat transfer from
the fuel stored in the SFP, there is sufficient time to initiate
appropriate mitigating actions, and if needed, for offsite authorities
to implement offsite protective actions using a CEMP approach to
protect the health and safety of the public.
With respect to design-basis accidents at TMI, the licensee
provided an analysis demonstrating that following permanent cessation
of power operations at TMI-1, the radiological consequences of the
remaining design-basis accidents with potential for offsite
radiological release (a fuel handling accident in the Fuel Handling
Building, where the SFP is located for TMI-1, and a fire in the Reactor
Building with the Reactor Building Purge System in operation for TMI-2)
will not exceed the
[[Page 78883]]
limits of the EPA PAGs at the exclusion area boundary.
With respect to beyond-design-basis accidents at TMI, the licensee
analyzed a drain down of the SFP water that would effectively impede
any decay heat removal. The analysis demonstrates that at 488 days
(approximately 16 months) after permanent cessation of power
operations, there would be 10 hours after the assemblies have been
uncovered until the limiting fuel assembly (for decay heat and
adiabatic heat-up analysis) reaches 900 degrees Celsius ([deg]C), the
temperature used to assess the potential onset of fission product
release. The analysis conservatively assumed that the heat-up time
starts when the SFP has been completely drained, although it is likely
that site personnel will start to respond to an incident when drain
down starts. The analysis also does not consider the period of time
from the initiating event causing loss of SFP water inventory until
cooling is lost.
The NRC reviewed the licensee's justification for the requested
exemptions against the criteria in 10 CFR 50.12(a) and determined, as
described below, that the criteria in 10 CFR 50.12(a) will be met, and
that the exemptions should be granted 488 days after TMI-1 has
permanently ceased power operations. An assessment of the Exelon EP
exemptions is described in SECY-20-0041, ``Request by Exelon Generation
Company, LLC for Exemptions from Certain Emergency Planning
Requirements for the Three Mile Island Nuclear Station,'' dated May 5,
2020 (ADAMS Package Accession No. ML19311C762). The Commission approved
the NRC staff's recommendation to grant the exemptions in the staff
requirements memorandum to SECY-20-0041, dated July 27, 2020 (ADAMS
Accession No. ML20209A439). Descriptions of the specific exemptions
requested by Exelon and the NRC staff's basis for granting each
exemption are provided in SECY-20-0041. The NRC staff's detailed review
and technical basis for the approval of the specific EP exemptions
requested by Exelon are provided in the NRC staff's safety evaluation
associated with this exemption (ADAMS Accession No. ML19311C762).
A. The Exemption Is Authorized by Law
The licensee has proposed exemptions from certain EP requirements
in 10 CFR 50.47(b), 10 CFR 50.47(c)(2), and 10 CFR part 50, Appendix E,
Section IV, that would allow Exelon to revise the TMI Emergency Plan to
reflect the permanently shutdown and defueled condition of the
facility. As stated above, in accordance with 10 CFR 50.12, the
Commission may, upon application by any interested person or upon its
own initiative, grant exemptions from the requirements of 10 CFR part
50. The NRC staff has determined that granting of the licensee's
proposed exemptions will not result in a violation of the Atomic Energy
Act of 1954, as amended, or the NRC's regulations. Therefore, the
exemptions are authorized by law.
B. The Exemption Presents No Undue Risk to Public Health and Safety
As stated previously, Exelon provided an analysis that shows that
the radiological consequences of design-basis accidents will not exceed
the limits of the EPA early phase PAGs at the exclusion area boundary.
Therefore, formal offsite radiological emergency preparedness plans
required under 10 CFR part 50 will no longer be needed for protection
of the public beyond the exclusion area boundary, based on the
radiological consequences of design-basis accidents still possible at
TMI 488 days after TMI-1 has permanently ceased power operations.
Although highly unlikely, there is one postulated beyond-design-
basis accident that might result in significant offsite radiological
releases. However, NUREG-1738 confirms that the risk of beyond-design-
basis accidents is greatly reduced at permanently shutdown and defueled
reactors. The NRC staff's analyses in NUREG-1738 conclude that the
event sequences important to risk at permanently shutdown and defueled
power reactors are limited to large earthquakes and cask drop events.
For EP assessments, this is an important difference relative to
operating power reactors, where typically a large number of different
sequences make significant contributions to risk. As described in
NUREG-1738, relaxation of offsite EP requirements in 10 CFR part 50
beyond a few months after shutdown resulted in only a small change in
risk. The report further concludes that the change in risk due to
relaxation of offsite EP requirements is small because the overall risk
is low, and because even under current EP requirements for operating
power reactors, EP was judged to have marginal impact on evacuation
effectiveness for the severe earthquakes that dominate SFP risk. All
other sequences including cask drops (for which offsite radiological
emergency preparedness plans are expected to be more effective) are too
low in likelihood to have a significant impact on risk.
Therefore, granting exemptions to eliminate the requirements of 10
CFR part 50 to maintain offsite radiological emergency preparedness
plans and to reduce the scope of onsite EP activities will not present
an undue risk to the public health and safety.
C. The Exemption Is Consistent With the Common Defense and Security
The requested exemptions only involve EP requirements under 10 CFR
part 50 and will allow Exelon to revise the TMI Emergency Plan to
reflect the permanently shutdown and defueled condition of the
facility. Physical security measures at TMI are not affected by the
requested EP exemptions. The discontinuation of formal offsite
radiological emergency preparedness plans and the reduction in scope of
the onsite EP activities at TMI will not adversely affect Exelon's
ability to physically secure the site or protect special nuclear
material. Therefore, the proposed exemptions are consistent with common
defense and security.
D. Special Circumstances
Special circumstances, in accordance with 10 CFR 50.12(a)(2)(ii),
are present whenever application of the regulation in the particular
circumstances is not necessary to achieve the underlying purpose of the
rule. The underlying purpose of 10 CFR 50.47(b), 10 CFR 50.47(c)(2),
and 10 CFR part 50, Appendix E, Section IV, is to provide reasonable
assurance that adequate protective measures can and will be taken in
the event of a radiological emergency, to establish plume exposure and
ingestion pathway emergency planning zones for nuclear power plants,
and to ensure that licensees maintain effective offsite and onsite
radiological emergency preparedness plans. The standards and
requirements in these regulations were developed by considering the
risks associated with operation of a power reactor at its licensed
full-power level. These risks include the potential for a reactor
accident with offsite radiological dose consequences.
As discussed previously in Section III, because TMI will be
permanently shut down and defueled, there will no longer be a risk of a
significant offsite radiological release from a design-basis accident
exceeding EPA early phase PAGs at the exclusion area boundary and the
risk of a significant offsite radiological release from a beyond-
design-basis accident is greatly reduced when compared to an operating
power reactor. The NRC staff has confirmed the reduced risks at TMI by
comparing the generic risk assumptions in the analyses in NUREG-1738 to
site-specific conditions at TMI and determined that
[[Page 78884]]
the risk values in NUREG-1738 bound the risks presented at TMI. As
indicated by the results of the research conducted for NUREG-1738, and
more recently for NUREG-2161, ``Consequence Study of a Beyond-Design-
Basis Earthquake Affecting the Spent Fuel Pool for a U.S. Mark I
Boiling Water Reactor,'' dated September 2014 (ADAMS Accession No.
ML14255A365), while other consequences can be extensive, accidents from
SFPs with significant decay time have little potential to cause offsite
early fatalities, even if the formal offsite radiological EP
requirements were relaxed. The licensee's analysis of a beyond-design-
basis accident involving a complete loss of SFP water inventory, based
on an adiabatic heat-up analysis of the limiting fuel assembly for
decay heat, shows that 488 days after permanent cessation of power
operations at TMI-1, the time for the limiting fuel assembly to reach
900 [deg]C is at least 10 hours after the assemblies have been
uncovered assuming a loss of all cooling means.
The only analyzed beyond-design-basis accident scenario that
progresses to a condition where a significant offsite release might
occur, involves the highly unlikely event where the SFP drains in such
a way that all modes of cooling or heat transfer are assumed to be
unavailable, which is referred to as an adiabatic heat-up of the spent
fuel. The licensee's analysis of this beyond-design-basis accident
shows that 488 days after permanent cessation of power operations at
TMI-1, at least 10 hours would be available between the time that all
cooling means are lost to the fuel (at which time adiabatic heat-up is
conservatively assumed to begin), until the fuel cladding reaches a
temperature of 1652 degrees Fahrenheit (900 [deg]C), which is the
temperature associated with rapid cladding oxidation and the potential
for a significant radiological release. This analysis conservatively
does not include the period of time from the initiating event causing a
loss of SFP water inventory until all cooling means are lost.
The NRC staff has verified Exelon's analyses and its calculations.
The analyses provide reasonable assurance that in granting the
requested exemptions to Exelon, there is no design-basis accident that
will result in an offsite radiological release exceeding the EPA early
phase PAGs at the exclusion area boundary. In the highly unlikely event
of a beyond-design-basis accident affecting the SFP that results in a
complete loss of heat removal via all modes of heat transfer, there
will be over 10 hours available before an offsite release might occur
and, therefore, at least 10 hours to initiate appropriate mitigating
actions to restore a means of heat removal to the spent fuel. If a
radiological release were projected to occur under this highly unlikely
scenario, a minimum of 10 hours is considered sufficient time for
offsite authorities to implement protective actions using a CEMP
approach to protect the health and safety of the public.
Exemptions from the offsite EP requirements in 10 CFR part 50 have
previously been approved by the NRC when the site-specific analyses
show that at least 10 hours is available following a loss of SFP
coolant inventory accident with no air cooling (or other methods of
removing decay heat) until cladding of the hottest fuel assembly
reaches the rapid oxidation temperature. The NRC staff concluded in its
previously granted exemptions, as it does with Exelon's requested EP
exemptions, that if a minimum of 10 hours is available to initiate
mitigative actions consistent with plant conditions or, if needed, for
offsite authorities to implement protective actions using a CEMP
approach, then formal offsite radiological emergency preparedness
plans, required under 10 CFR part 50, are not necessary at permanently
shutdown and defueled facilities.
Additionally, TMI committed to maintaining SFP makeup strategies in
its application. The multiple strategies for providing makeup to the
SFP include: using existing plant systems for inventory makeup; an
internal strategy that relies on the fire protection system with
redundant pumps (one diesel-driven and one electric motor-driven); and
an off-site fire truck that can take suction from the Susquehanna
River. These strategies will continue to be required as condition
2.c.(17), ``Mitigation Strategy License Condition,'' of the TMI-1
Renewed Facility Operating License. Considering the very low
probability of beyond-design-basis accidents affecting the SFP, these
diverse strategies provide multiple methods to obtain additional makeup
or spray to the SFP before the onset of any postulated offsite
radiological release.
For all of the reasons stated above, the NRC staff finds that the
licensee's requested exemptions meet the underlying purpose of all of
the standards in 10 CFR 50.47(b), and requirements in 10 CFR
50.47(c)(2) and 10 CFR part 50, Appendix E, and satisfy the special
circumstances provision in 10 CFR 50.12(a)(2)(ii) in view of the
greatly reduced risk of offsite radiological consequences associated
with the permanently shutdown and defueled state of the TMI facility
488 days after permanent cessation of power operations of TMI-1.
The NRC staff has concluded that the exemptions being granted by
this action will maintain an acceptable level of emergency preparedness
at TMI and, if needed, that there is reasonable assurance that adequate
offsite protective measures can and will be taken by State and local
government agencies using a CEMP approach in the highly unlikely event
of a radiological emergency at TMI. Since the underlying purpose of the
rules, as exempted, would continue to be achieved, even with the
elimination of the requirements under 10 CFR part 50 to maintain formal
offsite radiological emergency preparedness plans and the reduction in
the scope of the onsite emergency planning activities at TMI, the
special circumstances required by 10 CFR 50.12(a)(2)(ii) exist.
E. Environmental Considerations
In accordance with 10 CFR 51.31(a), the Commission has determined
that the granting of this exemption will not have a significant effect
on the quality of the human environment as discussed in the NRC staff's
Finding of No Significant Impact and associated Environmental
Assessment published in the Federal Register on September 22, 2020 (85
FR 59565).
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12, Exelon's request for exemptions from certain EP requirements in
10 CFR 50.47(b), 10 CFR 50.47(c)(2), and 10 CFR part 50, Appendix E,
Section IV, and as summarized in Enclosure 2 to SECY-20-0041, are
authorized by law, will not present an undue risk to the public health
and safety, and are consistent with the common defense and security.
Also, special circumstances are present. Therefore, the Commission
hereby grants Exelon's exemptions from certain EP requirements in 10
CFR 50.47(b), 10 CFR 50.47(c)(2), and 10 CFR part 50, Appendix E,
Section IV, as discussed and evaluated in detail in the NRC staff's
safety evaluation associated with this exemption. The exemptions are
effective as of 488 days after permanent cessation of power operations
of TMI-1.
Dated: December 1, 2020.
For the Nuclear Regulatory Commission.
Patricia K. Holahan, Director,
Division of Decommissioning, Uranium Recovery, and Waste
Programs, Office of Nuclear Material Safety and Safeguards.
[FR Doc. 2020-26767 Filed 12-4-20; 8:45 am]
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