ML24082A069
| ML24082A069 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 04/19/2024 |
| From: | Yoira Diaz-Sanabria Storage and Transportation Licensing Branch |
| To: | |
| Nguyen J, NMSS/DFM/STLB | |
| Shared Package | |
| ML24082A041 | List: |
| References | |
| 89 FR 31226, NRC-2024-0064 | |
| Download: ML24082A069 (1) | |
Text
[7590- 01-P]
NUCLEAR REGULATORY COMMISSION
[Docket Nos. 72-1048, 50 -390, and 50 -391; NRC- 2024- 0064]
Tennessee Valley Authority;
Watts Bar Nuclear Plant, Units 1 and 2;
Independent Spent Fuel Storage Installation;
Exemption
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice; issuance.
SUMMARY
- The U.S. Nuclear Regulatory Commission (NRC) issued an exemption to
Tennessee Valley Authority permitting Watts Bar Nuclear Plant to load five of the model
37 multi- purpose canisters (MPC) with continuous basket shims beginning July 2024 in
the HI-STORM Flood/Wind MPC Storage System at its Watts Bar Nuclear Plant , Units 1
and 2 independent spent fuel storage installation in a storage condition where the terms,
conditions, and specifications in the Certificate of Compliance No. 1032 , Amendment
No. 0, Revision No. 1 are not met.
DATES: The exemption was issued on April 17, 2024.
ADDRESSES: Please refer to Docket ID NRC- 2024- 0064 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 Webs ite: Go to https://www.regulations.gov and
search for Docket ID NRC-2024- 0064. Address questions about D ocket IDs in
Regulations.gov to Stacy Schumann; telephone: 301- 415- 0624; email:
Stacy.Schumann@nrc.gov. For technical questions, contact the individual listed in the
For Further Information Contact section of this document.
- NRCs 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 NRCs Public Document Room (PDR) reference staff at 1- 800-397- 4209, at
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.
- NRCs 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 PDR.Resource@nrc.gov 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: John-Chau Nguyen, Office of Nuclear
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC
20555; telephone: 301- 415-0262; email: John- Chau.Nguyen@nrc.gov .
SUPPLEMENTARY INFORMATION: The text of the exemption is attached.
Dated: April 19, 2024.
For the Nuclear Regulatory Commission.
/RA/
Yoira Diaz-Sanabria, Chief, Storage and Transportation Licensing Branch, Division of Fuel Management, Office of Nuclear Material Safety, and Safeguards.
2 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 part 50.
TVA 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 WBN ISFSI. Under the
terms of the general license, TVA stores spent fuel at its WBN 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.
3 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 (ML16112A309). If approved, TVAs 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 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).
4 TVAs near-term loading campaign for the WBN ISFSI includes plans to load five
MPC CBS in the HI-STORM FW MPC Storage System beginning in July 2024. While
Holtec was 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 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 NRCs regulations or other applicable laws. Additionally,
5 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 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 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
6 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 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 exemption
request.
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
7 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.
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,
8 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 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
9 proposed action. The environmental assessment and the finding 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-37-CBS beginning in July 2024.
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.
10