ML24082A060
| ML24082A060 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 04/17/2024 |
| From: | Bernie White Storage and Transportation Licensing Branch |
| To: | Tennessee Valley Authority |
| Nguyen J, NMSS/DFM/STLB | |
| Shared Package | |
| ML24082A041 | List: |
| References | |
| Download: ML24082A060 (1) | |
Text
Attachment - Exemption
NUCLEAR REGULATORY COMMISSION
Docket Nos. 72- 1048, 50-390, and 50 -391
Tennessee Valley Authority
Watts Bar Nuclear Plant Units 1 and 2
Independent Spent Fuel Storage Installation;
I. Background
Tennessee Valley Authority (TVA) is the holder of Facility Operating License Nos. NPF -
90 and NPF-96, which authorize operation of the Watts Bar Nuclear Plant (WBN), Units 1 and 2
in Rhea County, Tennessee, 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.
Nuclear Regulatory Commission (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 p art 50. TVA is
authorized to operate nuclear power reactors under 10 CFR p art 50 and holds a 10 CFR part 72
general license for storage of spent fuel at the WBN ISFSI. Under the terms of the general
license, TVA stores spent fuel at its WB N ISFSI using the HI -STORM Flood/Wind ( FW) Multi-
Purpose Canister (MPC) Storage System in accordance with Certificate of Compliance (CoC)
No. 1032, Amendment No. 0, Revision No. 1.
II. Request/Action
By a letter dated February 28 , 2024 (Agencywide Documents Access and Management
System [ADAMS] Accession No. ML24059A369) , and supplemented on March 18, 2024
(ML24078A257), TVA requested an exemption from the requirements of 10 CFR §§
72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i), 72.212(b)(11), and 72.214 that require WBN to
comply with the terms, conditions, and specifications of the CoC No. 1032 , Amendment No. 0 ,
Revision No. 1 (ML16112A 309). If approved, TVA s exemption request would accordingly allow
WBN to load MPCs with continuous basket shims (CBS) (i.e., MPC CBS), an unapproved,
variant basket design, in the HI-STORM FW MPC Storage System, and thus, to load the
systems in a storage condition where the terms, conditions, and specifications in the CoC No.
1032, Amendment No. 0 , Revision No. 1 are not met.
TVA currently uses the HI-STORM FW MPC Storage System under CoC No. 1032,
Amendment No. 0 , Revision No. 1, for dry storage of spent nuclear fuel in MPC-37 at the WBN
ISFSI. Holtec International (Holtec), the designer and manufacturer of the HI-STORM FW MPC
Storage System, developed a variant of the design with CBS for the MPC-37, known as MPC -
37- CBS. Holtec performed a non-mechanistic tip -over analysis with favorable results and
implemented the CBS variant design under the provisions of 10 CFR 72.48, Changes, tests,
and experiments, which allows licensees to make changes to cask designs without a CoC
amendment under certain conditions (listed in 10 CFR 72.48(c)). After evaluating the specific
changes to the cask designs, the NRC determined that Holtec erred when it implemented the
CBS variant design under 10 CFR 72.48, as this is not the type of change allowed without a
CoC amendment. For this reason, the NRC issued three Severity Level IV violations to Holtec
(ML24016A190).
TVAs near -term loading campaign for the WBN ISFSI includes plans to load five MPC-
37- CBS in the HI-STORM FW MPC Storage System beginning in July 2024. While Holtec was
2 required to submit a CoC amendment to the NRC to seek approval of the CBS variant design,
such a process will not be completed in time to inform decisions for this near-term loading
campaign. Therefore, TVA submitted this exemption request in order to allow for future loading
of five MPC CBS beginning in July 2024 at the WBN ISFSI. This exemption is limited to the
use of MPC CBS in the HI-STORM FW MPC Storage System only for the specific near-term
planned loading of five canisters using the MPC CBS variant basket design.
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 TVA to load five MPC CBS in the HI-STORM FW MPC
Storage System, beginning July 2024, at its WBN ISFSI in a storage condition where the terms,
conditions, and specifications in the CoC No. 1032 , Amendment No. 0 , Revision No. 1, are not
met. WBN is requesting an exemption from the provisions in 10 CFR p art 72 that require the
licensee to comply with the terms, con ditions, 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 exemption s is consistent with the Atomic Energy Act of
1954, as amended, and is not otherwise inconsistent with NRCs regulations or other applicable
laws. Additionally, no other law proh ibits 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.
3 B. The Exemption Will Not Endanger Life or Property or the Common Defense and
Security
This exemption would allow TVA to load five MPC CBS in the HI-STORM FW MPC
Storage System, beginning July 2024, at the WBN ISFSI in a storage condition where the terms,
conditions, and specifications in the CoC No. 1032 , Amendment No. 0 , Revision No. 1, are not
met. In support of its exemption request, TVA asserts that issuance of the exemption would not
endanger life or property because a tip- over or handling event is administratively controlled, and
that the containment boundary would be maintained in such an event. TVA relies, in part, on
the approach in the NRCs Safety Determination Memorandum (ML24018A085). The NRC
issued this Safety Determination Memorandum to address whether, with respect to the
enforcement action against Holtec regarding this violation, there was any need to take an
immediate action for the cask systems that were already loaded with non- compliant basket
designs. The Safety Determination Memorandum documents a risk-informed approach
concluding that, during the design basis event of a non- mechanistic tip- over, the fuel in the
basket in the MPC-37-CBS remains in a subcritical condition.
TVA also provided site-specific technical information, as supplemented, including
information explaining why the use of the approach in the NRCs Safety Determination
Memorandum is appropriate for determining the safe use of the CBS variant baskets at the
WBN ISFSI. Specifically, TVA described that the analysis of the tip -over design basis event that
is relied upon in the NRCs Safety Determination Memorandum, which demonstrates that the
MPC confinement barrier is maintained, is documented in the updated final safety analysis
report (UFSAR) for the HI-STORM FW MPC Storage System CoC No. 1032, Amendment 0 ,
Revision No. 1 that is used at the WBN site. TVA stated the transporter for handling of the HI-
STORM FW MPC Storage System at the WBN ISFSI has redundant drop protection features
4 and was designed, fabricated, and tested in accordance with the applicable codes described in
the CoC No. 1032.
Additionally, TVA provided specific information from WBNs 72.212 Evaluation Report,
Revision 5, indicating the calculated total values for annual dose to any real individual who is
located beyond the controlled area are shown to be well below the limits required by 10 CFR
72.104(a), Criteria for radioactive materials in effluents and direct radiation from an ISFSI or
MRS. The analysis of a design basis accident scenario also demonstrates compliance with
72.106, Controlled area of an ISFSI or MRS . Specifically, TVA described that, in the highly
unlikely event of a tip- over, any potential fuel damage from a non- mechanistic tip-over event
would be localized, the confinement barrier would be maintained, and the shielding material
would remain intact. Coupled with the distance of the WBN ISFSI to the site area boundary,
TVA concluded that compliance with 72.104 and 72.106 is not impacted by approving this
The NRC staff reviewed the information provided by TVA and concludes that issuance of
the exemption would not endanger life or property because the administrative controls TVA has
in place at the WBN ISFSI sufficiently minimize the possibility of a tip-over or handling event,
and that the containment boundary would be maintained in such an event . The staff confirmed
that these administrative controls comply with the technical specifications and UFSAR for the
HI-STORM FW MPC Storage System CoC No. 1032, Amendment 0 , Revision No. 1 that is used
at the WBN site. In addition, the staff confirmed that the information provided by TVA regarding
WBNs 72.212 Evaluation Report, Revision 5 , demonstrates that the consequences of normal
and accident conditions would be within the regulatory limits of the 10 CFR 72.104 and 10 CFR
72.106. The staff also determined that the requested exemption is not related to any aspect of
the physical security or defense of the WBN ISFSI; therefore, granting the exemption would not
result in any potential impacts to common defense and security.
5 For these reasons, the NRC staff has 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 and, therefore, will not endanger life or property or the
common defense and security.
C. The Exemption is Otherwise in the Public Interest
The proposed exemption would allow WBN to load five MPC-37-CBS in the HI-STORM FW
MPC Storage System beginning in July 2024, at the WBN ISFSI, even though the CBS variant
basket design is not part of the approved CoC No. 1032, Amendment No. 0 , Revision No. 1.
According to TVA, the exemption is in the public interest because not being able to load fuel into
dry storage in the future loading campaign would impact TVAs ability to offload fuel from the
WBN reactor units, consequently impacting continued safe reactor operation.
TVA stated that to delay the future loading would impact the ability to effectively manage
the margin to full core discharge reserve in the WBN Unit 1 and Unit 2 spent fuel pools. WBNs
upcoming loading campaign was originally scheduled to begin on January 29, 2024, but was
postponed until July 2024 . Any further delay would lead to insufficient space in the spent fuel
pool for core offload and the shutdown of WBN Unit 2, which in turn would potentially impact the
energy supply in the area. According to TVA, the planned July 2024 loading campaign is the
latest, and only opportunity for cask loading to avoid loss of full core reserve in 2025.
For the reasons described by TVA in the exemption request, the NRC agrees that it is in
the public interest to grant the exemption. If the exemption is not granted, in order to comply
with the CoC, WBN would have to keep spent fuel in the spent fuel pool if it is not permitted to
be loaded into casks for future loading. This would impact the ability to manage the margin for
full core reserve in the WBN spent fuel pool. Increased inventory in the spent fuel pool would
likely require additional fuel moves, which could in turn increase dose to workers and the risk of
accidents during fuel handling operations. Moreover, once the spent fuel pool capacity is
6 reached, the ability to refuel the operating reactor is limited, thus affecting continued reactor
operations. As described by TVA, this scenario would possibly result in the shutdown of one
unit, which could potentially impact the energy supply in the area.
Therefore, the staff concludes that approving the exemption is in the public interest.
Environmental Consideration
The NRC staff also considered whether there would be any significant environmental
impacts associated with the exemption. For this proposed action, the NRC staff performed an
environmental assessment pursuant to 10 CFR 51.30. The environmental assessment
concluded that the proposed action would not significantly impact the quality of the human
environment. The NRC staff concluded that the proposed action would not result in any changes
in the types or amounts of any radiological or non- radiological effluents that may be released
offsite, and there would be no significant increase in occupational or public radiation exposure
because of the proposed action. The e nvironmental assessment and the f inding of no significant
impact was published on April 17, 2024 ( 89 FR 27465).
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 TVA an
exemption from the requirements of §§ 72.212(a)(2), 72.212(b)(3), 72.212(b)(5)(i),
72.212(b)(11), and 72.214 with respect to the future loading in the HI-STORM FW MPC Storage
System of five MPC CBS beginning in July 2024.
7 This exemption is effective upon issuance.
Dated: April 17, 2024 .
For the Nuclear Regulatory Commission.
/RA/
Bernard H. White, Acting Chief, Storage and Transportation Licensing Branch, Division of Fuel Management, Office of Nuclear Material Safety, and Safeguards.
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SUBJECT:
FEDERAL REGISTER NOTICE: ISSUANCE OF EXEMPTION FOR WATTS BAR UNITS 1 AND 2 INDEPENDENT SPENT FUEL STORAGE INSTALLATION EXEMPTION REQUEST
DOCUMENT DATE: April 17, 2024
ADAMS Accession No.: ML24082A060 OFFICE: NMSS/DFM NMSS/DFM NMSS/DFM NMSS/REFS NAME: JNguyen SFigueroa TBoyce RSun
DATE: 3/24/2024 3/25/2024 3/26/2024 3/25/2024
OFFICE NMSS/DFM OGC/NLO NMSS/DFM NAME HRodriguez ACoggins BWhite for YDiaz-Sanabria DATE 3/25/2024 4/05/2024 4/17/2024 OFFICIAL RECORD COPY
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