[Federal Register Volume 84, Number 117 (Tuesday, June 18, 2019)]
[Notices]
[Pages 28352-28357]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12803]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-219; NRC-2019-0096]
Exelon Generation Company LLC; Oyster Creek Nuclear Generating
Station
AGENCY: Nuclear Regulatory Commission.
ACTION: Exemption; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has reissued
exemptions originally approved on October 16, 2018, exempting Exelon
Generation Company, LLC (Exelon or the licensee) from certain emergency
planning (EP) requirements. The NRC is reissuing these exemptions to
change the effective date of the exemptions from date would change from
365 days to 285 days after the permanent cessation of power operations.
The reissued exemptions eliminated the requirements to maintain an
offsite radiological emergency preparedness plan and reduce the scope
of onsite EP activities at the Oyster Creek Nuclear Generating Station
(Oyster Creek), 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 reissued on June 11, 2019.
ADDRESSES: Please refer to Docket ID NRC-2019-0096 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 http://www.regulations.gov and search for Docket ID NRC-2019-0096. Address
questions about NRC docket IDs in Regulations.gov to Jennifer Borges;
telephone: 301-287-9127; email: [email protected]. For technical
questions, contact the individual listed
[[Page 28353]]
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 http://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. In addition, for the
convenience of the reader, the ADAMS accession numbers are provided in
a table in the ``Availability of Documents'' section of this document.
NRC's PDR: You may examine and purchase copies of public
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852.
FOR FURTHER INFORMATION CONTACT: Amy M. Snyder, Office of Nuclear
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001; telephone: 301-415-6822; email:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Background
The Commission has determined that, pursuant to section 50.12 of
title 10 of the Code of Federal Regulations (CFR), 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-18-0062, 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 285
days after permanent cessation of power operations.
II. Availability of Documents
The documents identified in the following table are available for
public inspection through ADAMS, a public web page, or by using one of
the methods discussed in the ADDRESSES section of this document.
----------------------------------------------------------------------------------------------------------------
Document title Date ADAMS accession No. or public web page
----------------------------------------------------------------------------------------------------------------
Exelon Generation Company, LLC, February 14, 2018................... ML18045A084.
letter to U.S. Nuclear Regulatory
Commission, ``Certification of
Permanent Cessation of Power
Operations for Oyster Creek
Nuclear Generating Station.''.
Exelon Generation Company, LLC, September 25, 2018.................. ML18268A258.
letter to U.S. Nuclear Regulatory
Commission, ``Certification of
Permanent Removal of Fuel from
the Reactor Vessel for Oyster
Creek Nuclear Generating
Station.''.
Exelon Generation Company, LLC, October 22, 2018.................... ML18295A384.
letter to U.S. Nuclear Regulatory
Commission, ``License Amendment
Request--Proposed Change of
Effective and Implementation
Dates of License Amendment No.
294, Oyster Creek Emergency Plan
for Permanently Defueled
Emergency Plan and Emergency
Action Level Scheme.''.
Exelon Generation Company, LLC, November 6, 2018.................... ML18310A306.
letter to U.S. Nuclear Regulatory
Commission, ``License Amendment
Request Supplement--Proposed
Change of Effective and
Implementation Dates of License
Amendment No. 294, Oyster Creek
Emergency Plan for Permanently
Defueled Emergency Plan and
Emergency Action Level Scheme.''.
Exelon Generation Company, LLC, February 13, 2019................... ML19044A643.
letter to U.S. Nuclear Regulatory
Commission, ``Response to Request
for Additional Information (RAI)
and Supplemental Information
Regarding Request for Changing
Emergency Preparedness License
Amendment No. 294 Effective
Date''.
U.S. Nuclear Regulatory August 1997......................... ML082260098.
Commission, NUREG/CR-6451, ``A
Safety and Regulatory Assessment
of Generic BWR and PWR
Permanently Shutdown Nuclear
Power Plants.''.
U.S. Nuclear Regulatory February 2001....................... ML010430066.
Commission, NUREG-1738,
``Technical Study of Spent Fuel
Pool Accident Risk at
Decommissioning Nuclear Power
Plants.''.
Federal Emergency Management November 2010....................... http://www.fema.gov/pdf/about/
Agency Comprehensive Preparedness divisions/npd/CPG_101_V2.pdf.
Guide 101, ``Developing and
Maintaining Emergency Operations
Plans,'' Version 2.0.
U.S. Nuclear Regulatory September 2014...................... ML14255A365.
Commission, NUREG-2161,
``Consequence Study of a Beyond
Design-Basis Earthquake Affecting
the Spent Fuel Pool for a U.S.
Mark I Boiling Water Reactor.''.
U.S. Nuclear Regulatory November 12, 2013................... ML13329A918
Commission, COMSECY-13-0030, (Package)
``Staff Evaluation and
Recommendation for Japan Lessons-
Learned Tier 3 Issue on Expedited
Transfer of Spent Fuel.''.
U.S. Nuclear Regulatory May 31, 2018........................ ML18030B340 (Package).
Commission, SECY-18-0062,
``Request by the Exelon
Generation Company, LLC for
Exemptions from Certain Emergency
Planning Requirements for the
Oyster Creek Nuclear Generating
Station.''.
U.S. Nuclear Regulatory July 17, 2018....................... ML18198A449.
Commission, ``Staff Requirements--
SECY-18-0062, Request by the
Exelon Generation Company, LLC
for Exemptions from Certain
Emergency Planning Requirements
for the Oyster Creek Nuclear
Generating Station.''.
Exelon Generation Company, LLC, March 8, 2018....................... ML18067A087.
letter to U.S. Nuclear Regulatory
Commission, ``Supplement to
Request for Exemption from
Portions of 10 CFR 50.47 and 10
CFR 50 part 50, Appendix E.''.
Exelon Generation Company, LLC, March 19, 2018...................... ML18078A146.
letter to U.S. Nuclear Regulatory
Commission, ``Response to Request
for Additional Information (RAI)
Related to Exemption Request from
Portions of 10 CFR 50.47 and 10
CFR 50 part 50, Appendix E.''.
[[Page 28354]]
U.S. Nuclear Regulatory October 16, 2018.................... ML18220A980.
Commission, letter to Exelon
Generation Company, LLC ``Oyster
Creek Nuclear Generating Station--
Exemptions from Certain Emergency
Planning Requirements and Related
Safety Evaluation.''.
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The text of the exemption is attached.
Dated at Rockville, Maryland, on June 13, 2019.
For the Nuclear Regulatory Commission.
Bruce A. 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 No. 50-219
Exelon Generation Company, LLC
Oyster Creek Nuclear Generating Station
Exemption
I. Background
Exelon Generation Company, LLC (Exelon or the licensee) is the
holder of Renewed Facility Operating License No. DPR-16 for Oyster
Creek Nuclear Generating Station (Oyster Creek). The license provides,
among other things, that the facility is subject to all rules,
regulations, and orders of the U.S. Nuclear Regulatory Commission (NRC)
now or hereafter in effect. The facility is located in Ocean County,
New Jersey.
By letter dated February 14, 2018 (Agencywide Documents Access and
Management System (ADAMS) Accession No. ML18045A084), Exelon submitted
a certification to the NRC that it would permanently cease power
operations at Oyster Creek no later than October 31, 2018. On September
17, 2018, Exelon permanently ceased power operations at Oyster Creek.
By letter dated September 25, 2018 (ADAMS Accession No. ML18268A258),
Exelon certified the permanent removal of fuel from the Oyster Creek
reactor vessel.
In accordance with Section 50.82(a)(2) of Title 10 of the Code of
Federal Regulations (10 CFR), the license for a power reactor facility
no longer authorizes operation of the reactor or emplacement or
retention of fuel into the reactor vessel upon the docketing of the
certifications for permanent cessation of operations and permanent
removal of fuel from 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 Oyster Creek spent fuel
pool (SFP) and a dry cask independent spent fuel storage installation
(ISFSI) at the Oyster Creek facility.
Many of the accident scenarios postulated in the updated final
safety analysis reports (UFSARs) 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 at Oyster Creek and the permanent
removal of the fuel from the reactor vessel, 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 shutdown 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.
On October 16, 2018, the NRC exempted Exelon from certain EP
requirements for Oyster Creek (ADAMS Accession No. ML18220A980). These
exemptions eliminated the requirements to maintain an offsite
radiological emergency preparedness plan and reduce the scope of onsite
EP activities at Oyster Creek, based on the reduced risks of accidents
that could result in an offsite radiological release at a
decommissioning nuclear power reactor. The October 16, 2018, exemptions
were to become effective no earlier than 12 months (365 days) after
permanent cessation of power operations at Oyster Creek.
II. Request/Action
By letter dated November 6, 2018 (ADAMS Accession No. ML18310A306),
as supplemented by letter dated February 13, 2019 (ADAMS Accession No.
ML19044A643), Exelon requested to modify the effective date of the
October 16, 2018, exemptions from 12 months (365 days) to 9.38 months
(285 days) after permanent cessation of power operations. Oyster Creek
permanently ceased power operations on September 17, 2018. Therefore,
the revised effective date of the exemptions would be June 29, 2019. To
provide a complete record of the NRC staff's review, the NRC is
reissuing the October 16, 2018, exemptions to reflect the revised
effective date. These reissued exemptions supersede the exemptions
issued on October 16, 2018.
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
[[Page 28355]]
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 irradiated 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
[Pressurized Water Reactor] 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 reports, the risk of offsite radiological release is
significantly less than for an operating power reactor.
The EP exemptions previously approved for Oyster Creek were 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's (EPA) early phase Protective Action
Guides (PAGs) of one roentgen equivalent man (rem) 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 Comprehensive Emergency
Management Program, or ``all-hazards,'' approach to protect the health
and safety of the public.
With respect to design-basis accidents at Oyster Creek, the
licensee demonstrated that, as of 33 days after the permanent cessation
of operations, the radiological consequences of the only remaining
design-basis accident with potential for offsite radiological release
(the fuel handling accident (FHA) in the Auxiliary Building, where the
SFP is located) will not exceed the limits of the EPA early phase PAGs
to the public beyond the exclusion area boundary. Exelon stated that
this analysis remains unchanged. Because the requested effective date
of the exemptions is 285 days following permanent cessation of power
operations, the 33-day decay period necessary for the FHA dose to
decrease within the EPA PAGs remains bounded.
With respect to beyond-design-basis accidents at Oyster Creek, the
licensee analyzed a drain down of the SFP water that would effectively
impede any decay heat removal. The analysis demonstrates that at 285
days after permanent cessation of power operations, there would be 10
hours after the assemblies have been uncovered with all cooling lost
until the limiting fuel assembly (for decay heat and adiabatic heatup
analysis) reaches 900 degrees Celsius ([deg]C), the temperature used to
assess the potential onset of fission product release. The analysis
conservatively assumes that the heat up time starts when the SFP has
been completely drained with all cooling lost, 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 exemptions,
including the modified effective date, 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 285
days after the permanent cessation of power operations. As discussed
above, in October 2018, the NRC staff previously granted Exelon
exemptions from the relevant EP requirements, with an effective date of
these exemptions being 365 days after the permanent cessation of
operations. Subsequently, in November 2018, Exelon requested to change
the effective date of these exemptions from 365 days to 285 days.
Consequently, the NRC is reissuing the October 2018 exemptions with a
revised effective date of 285 days after Oyster Creek has permanently
ceased operations.
An assessment of the Exelon EP exemptions originally issued on
October 16, 2018, is described in SECY-18-0062, ``Request by the Exelon
Generation Company, LLC for Exemptions from Certain Emergency Planning
Requirements for the Oyster Creek Nuclear Generating Station,'' dated
May 31, 2018 (ADAMS Accession No. ML18030B340). The Commission approved
the NRC staff's recommendation to grant the exemptions in the staff
requirements memorandum to SECY-18-0062, dated July 17, 2018 (ADAMS
Accession No. ML18198A449).
The NRC staff's detailed review and technical basis for the
approval of the specific EP exemptions are provided in the NRC staff's
safety evaluation associated with the October 16, 2018 exemptions
(ADAMS Accession No. ML18220A980). That safety evaluation remains valid
as to all aspects of the exemptions other than the revised effective
date. The NRC staff's detailed review and technical basis for the
modification of the effective date of the exemptions is provided in a
separate safety evaluation dated June 11, 2019 (ADAMS Accession No.
ML19095A873).
In sum, the NRC reviewed the licensee's justification for the
requested exemptions, including the modified effective date, 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 285 days after the permanent cessation of
power operations. To provide a complete record of the NRC staff's
analysis, the NRC is reissuing the specific EP exemptions with the
revised effective date of 285 days after the permanent cessation of
power operations.
A. The Exemptions are 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 50, Appendix E,
Section IV, that would allow Exelon to revise the Oyster Creek
Emergency Plan to reflect the permanently shutdown and defueled
condition of the facility. The licensee has also requested to modify
the effective date for the implementation of the previously approved
exemptions from 12 months to 9.38 months (285 days) after permanent
cessation of power operations. 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
reissuing the licensee's proposed exemptions, with the modified
effective date, 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.
[[Page 28356]]
B. The Exemption Presents No Undue Risk to Public Health and Safety
As stated previously, Exelon provided an analysis showing 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, based on the reduced risk of radiological consequences from
design-basis accidents still possible at Oyster Creek 285 days after
the plant has permanently ceased power operations, 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.
Exelon provided an analysis showing that, as of 33 days after
permanent cessation of power operations, the radiological consequences
of the only remaining design-basis accident with potential for offsite
radiological release (FHA in the Auxiliary Building) will not exceed
the limits of the EPA early phase PAGs to the public beyond the
exclusion area boundary. Because the requested effective date of the
exemption is 285 days following permanent cessation of power
operations, the 33-day decay necessary for the FHA dose to decrease
within the EPA PAGs remains bounded. Oyster Creek permanently ceased
power operations on September 17, 2018.
In addition, the licensee analyzed beyond-design-basis accidents at
Oyster Creek, which would result in a drain down of the SFP water that
would effectively impede any decay heat removal. The analysis
demonstrates that at 285 days 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 heatup analysis) reaches 900 [deg]C, the temperature used to
assess the potential onset of fission product release.
Exelon has demonstrated that sufficient time continues to exist to
implement prompt SFP mitigative action, and if warranted, for offsite
governmental officials to implement measures to protect the public
using a CEMP, or ``all-hazards,'' approach. As such, the determination
that 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 remains valid.
Further, 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, reissuing the previously approved exemptions with a
modified effective date of 9.28 months (285 days) after permanent
cessation of power operations will not present an undue risk to the
public health and safety.
C. The Exemptions are Consistent With the Common Defense and Security
The reissued exemptions involve EP requirements under 10 CFR part
50 and will allow Exelon to revise the Oyster Creek Emergency Plan to
reflect the permanently shutdown and defueled condition of the
facility. Physical security measures at Oyster Creek are not affected
by the reissued EP exemptions with the revised effective date. The
discontinuation of formal offsite radiological emergency preparedness
plans and the reduction in scope of the onsite EP activities at Oyster
Creek will not adversely affect Exelon's ability to physically secure
the site or protect special nuclear material. Therefore, the reissued
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 previously discussed, because Oyster Creek is permanently shut
down and defueled, there is no longer 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 Oyster Creek by comparing the
generic risk assumptions in the analyses in NUREG-1738 to site-specific
conditions at Oyster Creek and determined that the risk values in
NUREG-1738 bound the risks presented at Oyster Creek. 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
heatup analysis of the limiting fuel assembly for decay heat, shows
that within 285 days after permanent cessation of power operations, 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 heatup of the spent
fuel. The licensee's analysis of this beyond-
[[Page 28357]]
design-basis accident shows that within 285 days after permanent
cessation of power operations, at least 10 hours would be available
between the time that all cooling means are lost to the fuel (at which
time adiabatic heatup is conservatively assumed to begin), until the
fuel cladding reaches a temperature of 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 reissuing 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, or
``all-hazards,'' 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, Oyster Creek committed to maintaining SFP makeup
strategies in its letters to the NRC dated March 8 and 19, 2018 (ADAMS
Accession Nos. ML18067A087 and ML18078A146, respectively). 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 onsite diesel fire truck that can take
suction from the Barnegat Bay. These strategies will continue to be
required as condition 2.C.(8), ``Mitigation Strategy License
Condition,'' of renewed facility operating license DPR-16 for Oyster
Creek. 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, including the modified effective date,
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 Oyster Creek facility 285 days after permanent
cessation of power operations.
The NRC staff has concluded that the exemptions being granted by
this action will maintain an acceptable level of emergency preparedness
at Oyster Creek 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, or ``all-hazards,'' approach in
the unlikely event of a radiological emergency at Oyster Creek. Because
the underlying purposes 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 Oyster Creek, 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 reissuing the EP exemptions with a revised effective date will
not have a significant effect on the quality of the human environment.
The NRC staff previously analyzed the October 16, 2018, EP exemptions
in a Finding of No Significant Impact and associated Environmental
Assessment published in the Federal Register on August 13, 2018 (83 FR
40092). That evaluation remains valid as to all aspects of the EP
exemptions other than the revised effective date. The NRC staff
analyzed the environmental impacts of the revised effective date in a
separate Finding of No Significant Impact and associated Environmental
Assessment published in the Federal Register on May 1, 2019 (84 FR
18586).
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12, reissuing the specific EP exemptions originally granted on
October 16, 2018, with the revised effective date of 285 days after
permanent cessation of operations will not present an undue risk to the
public health and safety and is consistent with the common defense and
security. Also, special circumstances are present. Therefore, the
Commission hereby reissues Exelon's exemption from certain EP
requirements in 10 CFR 50.47(b), 10 CFR 50.47(c)(2), and 10 CFR part
50, Appendix E, as discussed and evaluated in detail in the NRC staff's
safety evaluation associated with these exemptions. Oyster Creek
permanently ceased power operations on September 17, 2018. Therefore,
the revised effective date of the reissued exemptions is June 29, 2019.
Dated at Rockville, Maryland, this 11th day of June, 2019.
For the Nuclear Regulatory Commission.
/RA/
John R. Tappert,
Director, Division of Decommissioning, Uranium Recovery and Waste
Processing.
[FR Doc. 2019-12803 Filed 6-17-19; 8:45 am]
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