[Federal Register Volume 91, Number 166 (Friday, August 28, 2026)]
[Notices]
[Pages 55631-55634]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-17577]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-424, 50-425, and 72-1039; NRC-2026-3895]
Southern Nuclear Operating Company; Vogtle Electric Generating
Plant Units 1 & 2; Independent Spent Fuel Storage Installation;
Exemption
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has issued a one-
time exemption to Southern Nuclear Operating Company (SNC), authorizing
Vogtle Electric Generating Plant Units 1 and 2 (Vogtle 1 and 2) to
retain a single Neutron Source Assembly (NSA) in its current storage
cell within a multi-purpose canister ((MPC-32), serial number MPC-707)
at the Vogtle Independent Spent Fuel Storage Installation, in a manner
that is inconsistent with the loading restrictions specified in
Certificate of Compliance (CoC) No. 1014, Amendment 11, for the HI-
STORM 100S Version B dry storage system. The exemption allows the NSA
to remain in a peripheral basket cell, contrary to Appendix B, Table
2.1-1, which restricts NSA containing assemblies to designated interior
cells. The NRC's determination is based on SNC's safety evaluation and
supporting analyses demonstrating that the configuration continues to
meet applicable safety requirements for criticality control, shielding,
thermal performance, structural integrity, and confinement.
DATES: The exemption was issued on August 21, 2026.
ADDRESSES: Please refer to Docket ID NRC-2026-3895 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-2026-3895. Address
questions about Docket IDs in Regulations.gov to Bridget Curran;
telephone: 301-415-1003; email: [email protected]. For technical
questions, contact the individual listed
[[Page 55632]]
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 ADAMS Public Search.''
For problems with ADAMS, please contact the NRC's Public Document Room
(PDR) reference staff at 1-800-397-4209, at 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.
NRC's PDR: The PDR, where you may examine and order copies
of publicly available documents, is open by appointment. To make an
appointment to visit the PDR, please send an email to
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except
Federal holidays.
FOR FURTHER INFORMATION CONTACT: Haimanot Yilma, Office of Nuclear
Material Safety and Safeguards, U.S. NRC, Washington, DC 20555;
telephone: 301-287-9070; email: [email protected].
SUPPLEMENTARY INFORMATION: The text of the exemption is attached.
Authority: 42 U.S.C. 2011 et seq.
Dated: August 25, 2026.
For the Nuclear Regulatory Commission.
Yoira Diaz-Sanabria,
Chief, Storage Transportation and Microreactors Licensing Branch,
Division of Spent Fuel Storage and Transportation, Office of Nuclear
Material Safety, and Safeguards.
Attachment--Exemption
NUCLEAR REGULATORY COMMISSION
Docket Nos. 50-424, 50-425, and 72-1039
Southern Nuclear Operating Company; Vogtle Electric Generating Plant
Units 1 & 2; Independent Spent Fuel Storage Installation; Exemption
I. Background
Southern Nuclear Operating Company (SNC) is the holder of
Facility Operating Licenses Nos. 50-424 and 50-425, which authorize
operation of Vogtle Electric Generating Plant Units 1 and 2 in
Georgia, pursuant to part 50 of title 10 of the Code of Federal
Regulations (10 CFR), ``Domestic Licensing of Production and
Utilization Facilities.'' The licenses provide, among other things,
that the facility is subject to all rules, regulations, and orders
of the U.S. NRC now or hereafter in effect.
Consistent with 10 CFR part 72, subpart K, ``General License for
Storage of Spent Fuel at Power Reactor Sites,'' a general license is
issued for the storage of spent fuel in an Independent Spent Fuel
Storage Installation (ISFSI) at power reactor sites to persons
authorized to possess or operate nuclear power reactors under 10 CFR
part 50.
SNC is authorized to operate nuclear power reactors under 10 CFR
part 50 and holds a 10 CFR part 72 general license for storage of
spent fuel at the Vogtle ISFSI. Under the terms of the general
license, SNC stores spent fuel at its Vogtle ISFSI using the HI-
STORM 100S system in accordance with CoC No. 1014, Amendment 11.
The HI-STORM 100 dry storage system is a passive design
providing the required safety functions of heat removal, criticality
control, shielding, and confinement. The system consists of multi-
purpose canisters (MPCs) that confine the spent fuel, a storage
overpack (HI-STORM 100S) for shielding and structural protection,
and a transfer cask (HI-TRAC) for loading, unloading, and transfer
operations. The MPC is a welded, cylindrical canister with a fuel
basket containing neutron-absorbing material for criticality
control, and all confinement boundary components are made of
stainless steel alloys.
The HI-STORM 100 dry storage system is certified to accommodate
spent fuel and specified non-fuel hardware (NFH), as defined in
Appendix B of CoC No.1014, which restricts Neutron Source Assembly
(NSA) containing assemblies to designated interior cells. NSAs are
among the authorized NFH types.
On December 8, 2025, SNC discovered that a NSA had been
misloaded in a peripheral cell of MPC-32, serial number MPC-707,
during the April 2024 dry cast storage fuel loading campaign at
Vogtle Units 1 and 2. This misloading occurred because NSAs were
mislabeled as burnable poison rod assemblies (BPRAs) in the
TracWorks database in 1997, due to the NSAs and BPRAs similarities
in appearance and serial number nomenclature. The clerical error was
not detected in SNC's fuel selection procedures, which led to the
improper loading during the 2024 dry cask storage fuel loading
campaign. This loading configuration is inconsistent with the
requirements of Appendix B, Section 2.1, ``Fuel Specifications and
Loading Conditions,'' and Section V, Table 2.1-1 of CoC No. 1014,
Amendment 11. These requirements restrict loading of this type of
NFH to specific interior basket locations (cells 13, 14, 19, and/or
20), with a maximum of one NSA per canister; peripheral cells are
not permitted for NSA placement.
Following the discovery of this error, SNC updated TracWorks
labels for all primary source assemblies at Vogtle to correctly
reflect their hardware type and completed an extent-of-condition
review of NSA labels and locations across all SNC PWR sites,
including spent fuel pool inventories and previously loaded dry cask
storage MPCs.
II. Request/Action
By letter dated April 6, 2026 (ML26096A485), SNC requested an
exemption from 10 CFR 72.212(b)(3) and 72.212(b)(11), to deviate
from CoC No. 1014, Amendment 11 (ML23328A045 (package)) restrictions
on NSA placement within the MPC-32 basket.
This exemption request seeks the NRC's authorization, pursuant
to 10 CFR 72.7, to permit a single NSA to remain in its as loaded
storage location in a peripheral basket cell of MPC-32, serial
number MPC-707.
III. Discussion
Pursuant to 10 CFR 72.7, ``Specific exemptions,'' the Commission
may, upon application by any interested person or upon its own
initiative, grant such exemptions from the requirements of the
regulations of 10 CFR part 72 as it determines are authorized by law
and will not endanger life or property or the common defense and
security and are otherwise in the public interest.
A. The Exemption Is Authorized by Law
This exemption would allow SNC to deviate from CoC No. 1014,
Amendment 11 NSA placement restrictions and keep the NSA in a
peripheral cell of MPC-707.
SNC is requesting an exemption from the provisions in 10 CFR
part 72 that require the licensee to comply with the terms,
conditions, and specifications of the CoC for the approved cask
model it uses. Section 72.7 allows the NRC to grant exemptions from
the requirements of 10 CFR part 72. This authority to grant
exemptions is consistent with the Atomic Energy Act of 1954, as
amended, and is not otherwise inconsistent with NRC's regulations or
other applicable laws. Additionally, no other law prohibits the
activities that would be authorized by the exemption. Therefore, the
NRC concludes that there is no statutory prohibition on the issuance
of the requested exemption, and the NRC is authorized to grant the
exemption by law.
B. The Exemption Will Not Endanger Life or Property or the Common
Defense and Security
This one-time exemption would allow SNC to retain a single NSA
loaded within a multi-purpose canister (MPC-32, serial number MPC-
707) at the Vogtle 1 & 2 units, in a manner that is inconsistent
with the loading restrictions specified in CoC No. 1014, Amendment
11, for the HI-STORM 100S Version B dry storage system. SNC's
evaluation concludes that retaining a single NSA in a peripheral
cell does not adversely affect criticality control, shielding,
thermal performance, structural integrity, or confinement functions
of the HI-STORM 100S system and MPC-32, as loaded. The NSA (a
Californium-252 primary source from Vogtle Unit 2 Cycle 1) has
decayed for over 34 years, reducing neutron emission to negligible
levels relative to a typical spent fuel assembly. Post-loading dose
surveys confirm compliance with regulatory dose limits.
The NRC staff has evaluated the SNC's assessment and determined
that under the requested exemption, the storage system will continue
to meet the safety requirements of 10 CFR part 72 and the offsite
dose limits of 10 CFR part 20, ``Standards for Protection Against
Radiation'', and, therefore, will not endanger life or property or
the common
[[Page 55633]]
defense and security. The NRC staff's review concluded, as discussed
below, that the proposed exemption from certain requirements of 10
CFR part 72 will not cause CoC No. 1014 to encounter conditions
beyond those for which it has already been evaluated and
demonstrated to meet the applicable safety requirements in 10 CFR
part 72. The NRC staff's evaluation focused on the application and
those calculations and analyses submitted with the application. The
NRC staff followed the guidance in NUREG-2215 to complete its safety
evaluation. The NRC's staff evaluation includes thermal,
containment, shielding, and criticality safety areas, which are the
relevant technical disciplines affected by this exemption.
Thermal Review: The objective of the thermal evaluation was to
confirm that the MPC-32, serial number MPC-707, with the improperly
loaded NSA met the thermal requirements described in 10 CFR part 72,
thereby allowing Vogtle Units 1 and 2 to continue to store the NSA
in a manner that is inconsistent with the loading restrictions
specified in CoC No. 1014, Amendment 11, for the HI-STORM 100S
Version B dry storage system. The NRC staff relied on the
information provided by the licensee in their exemption submittal
(submitted April 2026) and their 30-day special report (letter NL-
25-0474, January 2026).
As described in the licensee's, ``Request for Exemption from an
Allowable Contents Requirement contained in the Certificate of
Compliance Number 1014 of the HI-STORM 100S Version B Dry Cask
Storage,'' (Enclosure to NL-26-0138 of the April 2026 submittal),
the placement of a NSA in a peripheral cell (rather than in a
designated interior cell) of the MPC-32 canister was inconsistent
with the requirements of CoC 1014 of the HI-STORM 100S Version B Dry
Cask Storage System. To support the exemption request, the licensee
noted that the activity of an NSA (e.g., cobalt activation of its
stainless steel and Inconel portions) is bounded by the total
activity of a burnable absorber assembly that can be stored in a
peripheral cell of an MPC-32 basket. In addition, the licensee
indicated that the placement of the NSA had no effect on the thermal
safety evaluation, since the loaded NSA produced negligible decay
heat and the evaluation is based on the bounding decay heat per cell
location.
After reviewing this assessment, the NRC staff concludes that,
because the activity of an NSA is bounded by the total activity of a
burnable absorber assembly, and because of the negligible decay heat
from the loaded NSA, placing the NSA in a peripheral cell of the
MPC-32 basket, contrary to CoC No. 1014 (Amendment 11) requirements,
would not change the thermal evaluation. Therefore, the NRC staff
finds that the thermal function of MPC-32 (serial number MPC-707)
loaded under CoC No. 1014, Amendment 11, as addressed in the
exemption request, remains in compliance with 10 CFR part 72.
Confinement Review: The objective of the confinement evaluation
was to confirm that MPC-32, serial number MPC-707, with the
improperly loaded NSA met the confinement requirements described in
10 CFR part 72, thereby allowing Vogtle Units 1 and 2 to continue to
store the NSA in a manner that is inconsistent with the loading
restrictions specified in CoC No. 1014, Amendment 11, for the HI-
STORM 100S Version B dry storage system. The NRC staff relied on the
information provided by the licensee in their exemption submittal
(submitted April 2026) and their 30-day special report (letter NL-
25-0474, January 2026).
As described in the licensee's, ``Request for Exemption from an
Allowable Contents Requirement contained in the Certificate of
Compliance Number 1014 of the HI-STORM 100S Version B Dry Cask
Storage,'' (Enclosure to NL-26-0138 of the April 2026 submittal),
the placement of a NSA in a peripheral cell (rather than in a
designated interior cell) of the MPC-32 canister's basket was
inconsistent with the requirements of CoC No. 1014 of the HI-STORM
100S Version B Dry Cask Storage System. To support the exemption
request, the licensee indicated that the placement of the NSA had no
effect on confinement safety evaluations and that the MPC (i.e., the
confinement boundary, which is tested to ``leaktight''
specifications as described in chapters 7 and 9 of HI-STORM 100
final safety analysis report (FSAR) revision 16) continued to have
no credible leakage. The licensee noted that the activity of an NSA
(e.g., cobalt activation of its stainless steel and Inconel
portions) is bounded by the total activity of a burnable absorber
assembly that can be stored at a peripheral cell of an MPC-32
basket, such that there is no significant change in content activity
within the MPC-32. In addition, the licensee noted that the
distinction between an NSA and burnable absorber assembly has no
effect on structural evaluations.
After reviewing this assessment, the NRC staff agrees that the
placement of the NSA had no effect on confinement safety evaluations
as the activity of the NSA is bounded by the total activity of a
burnable absorber assembly that can be stored in a peripheral cell,
and, therefore, concludes that placing the NSA in a peripheral cell
of the MPC-32 basket, contrary to CoC No. 1014 (Amendment 11)
requirements, would not change the confinement evaluation.
Therefore, the NRC staff finds that the confinement function of MPC-
32 (serial number MPC-707), loaded under CoC No. 1014, Amendment 11,
as addressed in the exemption request, remains in compliance with 10
CFR part 72.
Shielding Evaluation: The NRC staff reviewed SNC's exemption
request to deviate from CoC No. 1014 requirements, to ensure that
the shielding is adequate to meet requirements in 10 CFR part 72,
thereby allowing Vogtle Units 1 and 2 to continue to store the NSA
in a manner that is inconsistent with the loading restrictions
specified in CoC No. 1014, Amendment 11, for the HI-STORM 100S
Version B dry storage system. For shielding purposes, the NRC staff
reviewed the exemption request for compliance with the requirements
of 10 CFR 72.12(b)(3), 72.212(b)(11), 72.126(a)(6), 72.104 and
72.106.
The shielding design is described in Holtec International's FSAR
for the HI-STORM 100 cask system and CoC No. 1014. Gamma radiation
shielding is provided by the welded cylindrical MPC, as well as the
steel and concrete of the overpack. Neutron radiation shielding is
provided by the concrete of the overpack.
According to the licensee, for the NSA containing a Cf-252
source (half-life of 2.64 years), the inadvertent placement in
peripheral cell MPC-32, serial number MPC-707, instead of one of the
internal cells (No. 13, 14, 19, or 20), results in negligible
effects on the cask's radiation dose rates. The licensee noted that
the Cf-252 source has been decaying for over 34 years before being
placed inside the cask, reducing its neutron emission to less than
0.011% of its original source strength. The licensee's dose analysis
performed demonstrated that even in peripheral locations, the dose
impact is negligible if only one NSA per quadrant is loaded and
sufficient decay time has elapsed. This condition is met by the NSA.
Due to the bounding gamma source term applicable to the non-fuel
hardware (NFH) already in the MPC, the licensee indicated that
shielding calculation for gamma source term produced from neutron
activation from the Cf-252 source is not necessary to be performed.
Based on a review of the statements and representations
contained in the application, specifically the decay time of the
NSA, the negligible effects on the cask's radiation dose rate, and
the dose analysis performed, the NRC staff agrees that the shielding
is adequate with the incorrectly placed NSA. Therefore, the NRC
staff finds that the shielding function of MPC-32 (serial number
MPC-707) loaded under CoC No. 1014, Amendment 11, as addressed in
the exemption request, remains in compliance with 10 CFR part 72.
Criticality Evaluation: The NRC staff reviewed SNC's exemption
request to deviate from CoC No. 1014 requirements to ensure that the
criticality safety analysis remains adequate to meet requirements in
10 CFR part 72, which would allow Vogtle Units 1 and 2 to continue
to store the NSA in a manner that is inconsistent with the loading
restrictions specified in CoC No. 1014, Amendment 11, for the HI-
STORM 100S Version B dry storage system. The NRC staff reviewed the
exemption request for compliance with the requirements of 10 CFR
72.124 and 72.236.
The criticality safety design is described in Holtec
International's FSAR for the HI-STORM 100 cask system and CoC No.
1014. Criticality control is primarily provided by the allowable
contents and the requisite basket configuration that contains
neutron-absorbing material.
The licensee explained that the misplaced NSA in a peripheral
cell MPC-32 (serial number MPC-707), results in negligible effects
on the cask's criticality safety. As stated in the FSAR, fuel
assemblies containing start-up neutron sources are permitted for
storage in the HI-STORM 100 system. The reactivity of a fuel
assembly is not affected by the presence of a neutron source because
in a system with a keff less than 1.0, any given neutron
population at any time, regardless of its origin or size, will
decrease over time. Therefore, a neutron source of any strength will
not increase reactivity, but only the neutron flux in a
[[Page 55634]]
system, and thus no additional criticality analyses are required.
Sources are inserted as rods into fuel assemblies (i.e., they
replace either a fuel rod or water rod), displacing fuel material.
Since the criticality safety of the system is based on the neutron
interaction between the stored fuel assemblies, and since no
additional uranium mass has been added to the cask, only shifted
within the cask, the current analysis for the HI-STORM 100 cask
system bounds this loading error.
Based on a review of the statements and representations
contained in the application, the NRC staff agrees that because the
current analysis of the HI-STORM 100 cask system bounds the loading
error of the NSA in an unapproved configuration, the criticality
safety analysis remains adequate. Therefore, the NRC staff finds
that the criticality safety function of the MPC-32 (serial number
MPC-707) loaded under CoC No. 1014, Amendment 11, as addressed in
the exemption request, remains in compliance with 10 CFR part 72.
C. The Exemption Is Otherwise in the Public Interest
This exemption would allow SNC to deviate from the placement
restrictions outlined in CoC No. 1014, Amendment 11, allowing the
NSA to remain in a peripheral cell of MPC-32, serial number MPC-707.
According to SNC, the exemption is in the public interest
because it prevents unnecessary reflooding and unloading of the
canister, which would otherwise increase personnel radiation
exposure, generate contaminated waste, and introduce additional
operational risks without providing any corresponding safety
benefit.
Upon NRC staff review, the NRC staff agrees with the licensee's
assessment and concludes that granting the exemption serves the
public interest by enabling continued safe storage of the NSA,
without compromising safety, increasing personnel dose, or
introducing unintended operational issues.
Environmental Consideration
The NRC staff also considered whether there would be any
significant environmental impacts associated with the exemption. The
NRC staff has determined that this action is categorically excluded
under 10 CFR 51.22(d)(7), and there are no extraordinary
circumstances present that would preclude reliance on this
exclusion. The NRC staff have made this finding because the action
results only in a change in process operations/equipment and does
not involve ground disturbance, changes in effluents, or increased
additional exposure or increased accident consequences. Therefore,
pursuant to 10 CFR 51.22, the NRC staff concludes that this action
does not require either an environmental assessment or an
environmental impact statement. Additionally, the NRC staff has
determined that this action does not have the potential to cause
effects on historic properties. Therefore, in accordance with 36 CFR
800.3(a)(1), the NRC has no further obligation under Section 106 of
the National Historic Preservation Act. The NRC staff has also
determined that the action would have no effect on listed species or
critical habitats, therefore, consultation is not required under
section 7 of the Endangered Species Act.
IV. Conclusion
Based on these considerations, the NRC has determined that,
pursuant to 10 CFR 72.7, the exemption is authorized by law, will
not endanger life or property or the common defense and security,
and is otherwise in the public interest. Therefore, the NRC grants
SNC an exemption from 10 CFR 72.212(b)(3) and 72.212(b)(11), to
deviate from CoC No. 1014, Amendment 11, Appendix B, Table 2.1-1
requirements which restricts NSA containing assemblies to designated
interior cells and allow the single NSA to remain in a peripheral
basket cell of MPC-32, serial number MPC-707 under CoC No. 1014,
Amendment 11.
This exemption is effective upon issuance.
Dated: August 21, 2026.
For the Nuclear Regulatory Commission.
/RA/
Yoira Diaz Sanabria,
Chief, Storage, Transportation and Microreactors Licensing Branch,
Division of Spent Fuel Storage and Transportation, Office of Nuclear
Material Safety and Safeguards.
[FR Doc. 2026-17577 Filed 8-27-26; 8:45 am]
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