ML24065A483
| ML24065A483 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/01/2024 |
| From: | Yoira Diaz-Sanabria Storage and Transportation Licensing Branch |
| To: | |
| Shared Package | |
| ML24065A481 | List: |
| References | |
| NRC-2024-0054, 89FR24879 | |
| Download: ML24065A483 (1) | |
Text
[7590- 01-P]
NUCLEAR REGULATORY COMMISSION
[Docket Nos. 72-37, 50 -237, and 50- 249; NRC-2024-0054]
Constellation Energy Generation, LLC;
Dresden Nuclear Power Station, Unit 2 and Unit 3;
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
Constellation Energy Generation, LLC permitting Dresden Nuclear Power Station
(Dresden) to maintain loaded and to load 68M multi-purpose canisters with continuous
basket shims in the HI-STORM 100 Cask System at its Dresden Unit 2 and Unit 3
independent spent fuel storage installation in a storage condition where the terms,
conditions, and specifications in the Certificate of Compliance No. 1014, Amendment
No. 8, Revision No. 1 are not met.
DATES: The exemption was issued on April 1, 2024.
ADDRESSES: Please refer to Docket ID NRC-2024-0054 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- 0054. 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: Yen-Ju Chen, Office of Nuclear Material
Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555;
telephone: 301-415-1018; email: Yen -Ju.Chen@nrc.gov.
SUPPLEMENTARY INFORMATION: The text of the exemption is attached.
Dated: April 3, 2024.
For the Nuclear Regulatory Commission.
/RA/
Yoira K. 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. 72-37, 50-237, and 50- 249
Constellation Energy Generation, LLC
Dresden Nuclear Power Station Unit 2 and Unit 3
Independent Spent Fuel Storage Installation;
I. Background
Constellation Energy Generation, LLC (Constellation) is the holder of Renewed
Facility Operating License Nos. DPR-19 and DPR-25, which authorize operation of the
Dresden Nuclear Power Station, Unit 2 and Unit 3 (Dresden) in Morris, Illinois, 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.
Constellation 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 Dresden ISFSI.
Under the terms of the general license, Constellation stores spent fuel at its Dresden
ISFSI using the HI-STORM 100 Cask System in accordance with Certificate of
Compliance (CoC) No. 1014, Amendment No. 8, Revision No. 1.
3 II. Request/Action
By a letter dated February 23, 2024 (Agencywide Documents Access and
Management System [ADAMS] Accession No. ML24054A031), and supplemented on
February 28, 2024 (ML24065A292) and March 8, 2024 (ML24068A069), Constellation
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 Dresden to comply with the
terms, conditions, and specifications of the CoC No. 1014, Amendment No. 8, Revision
No. 1 (ML16041A233). If approved, Constellations exemption request would accordingly
allow Dresden to maintain loaded and to load Multi-Purpose Canisters (MPC) with an
unapproved, variant basket design (i.e., MPC-68M-CBS) in the HI-STORM 100 Cask
System, and thus, to load the systems in a storage condition where the terms,
conditions, and specifications in the CoC No. 1014, Amendment No. 8, Revision No. 1
are not met.
Constellation currently uses the HI-STORM 100 Cask System under CoC No.
1014, Amendment No. 8, Revision No. 1, for dry storage of spent nuclear fuel in MPC-
68M at the Dresden ISFSI. Holtec International (Holtec), the designer and manufacturer
of the HI-STORM 100 Cask System, developed a variant of the design with continuous
basket shims (CBS) for the MPC-68M, known as MPC-68M-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
4 change allowed without a CoC amendment. For this reason, the NRC issued three
Severity Level IV violations to Holtec (ML24016A190).
Prior to the issuance of the violations, Constellation had loaded four MPC-68M-
CBS in the HI-STORM 100 Cask System, which are safely in storage at the Dresden
ISFSI. Constellations near-term loading campaigns for the Dresden ISFSI include plans
to load one MPC -68M-CBS in the HI-STORM 100 Cask System in May 2024 and four
MPC-68M-CBS in March 2025. 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 these near -term loading campaigns. Therefore,
Constellation submitted this exemption request in order to allow for the continued
storage of the four already loaded MPC-68M-CBS, and future loadings of one MPC-
68M-CBS in May 2024 and four in March 2025, at the Dresden ISFSI. This exemption is
limited to the use of MPC-68M -CBS in the HI-STORM 100 Cask System only for the four
already loaded systems and specific near-term planned loadings of five systems using
the MPC-68M-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 Constellation to maintain loaded and to load MPC-
68M-CBS in the HI-STORM 100 Cask System at its Dresden ISFSI in a storage
condition where the terms, conditions, and specifications in the CoC No. 1014,
5 Amendment No. 8, Revision No. 1, are not met. Constellation 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, 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 Constellation to maintain loaded and to load MPC-
68M-CBS in the HI-STORM 100 Cask System at the Dresden ISFSI in a storage
condition where the terms, conditions, and specifications in the CoC No. 1014,
Amendment No. 8, Revision No. 1, are not met. In support of its exemption request,
Constellation asserts that issuance of the exemption would not endanger life or property
because the administrative controls the applicant has in place prevent a tip-over or
handling event, and that the containment boundary would be maintained in such an
event. Constellation 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,
6 during the design basis event of a non-mechanistic tip-over, the fuel in the basket in the
MPC-68M-CBS remains in a subcritical condition.
Constellation 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 Dresden ISFSI. Specifically, Constellation 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 100 Cask System CoC No. 1014, Amendment 8, Revision No. 1 that is used
at the Dresden site. Constellation also described its administrative controls for handling
of the HI-STORM 100 Cask System at the Dresden ISFSI to prevent a tip-over or
handling event. Those controls include operational procedures that demonstrate that the
system is handled with a single failure proof device, complying with ANSI N14.6, for
Radioactive Materials - Special Lifting Devices for Shipping Containers Weighing 10 000
Pounds (4500 kg) or More, and consistent with NUREG-612, Control of Heavy Loads
at Nuclear Power Plants, (ML070250180) for heavy load lifting component, inside of the
Reactor Buildings and during transport to the ISFSI. In addition, the transporter includes
redundant drop protection.
Additionally, Constellation provided specific information from Dresdens 72.212
Evaluation Report, Revision 15, indicating that during the design basis event of a non-
mechanistic tip-over, Dresdens ISFSI would meet the requirements in 10 CFR 72.104,
Crit eria for radioactive materials in effluents and direct radiation from an ISFSI or MRS,
and 72.106, Controlled area of an ISFSI or MRS. Specifically, Constellation described
that, in the highly unlikely event of a tip-over, any potential fuel damage from a non-
7 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 Dresden ISFSI to the site area boundary, Constellation 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 Constellation and concludes
that issuance of the exemption would not endanger life or property because the
administrative controls Constellation has in place at the Dresden 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 100 Cask System CoC No. 1014, Amendment 8, Revision No. 1 that is used at
the Dresden site. In addition, the staff confirmed that the information provided by
Constellation regarding Dresdens 72.212 Evaluation Report, Revision 15, 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 Dresden 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 the four already loaded MPC-68M-CBS in the
HI-STORM 100 Cask System to remain in storage at the Dresden ISFSI, and allow
8 Constellation to load one MPC-68M-CBS in the HI-STORM 100 Cask System in May
2024 and four MPC-68M-CBS in March 2025,at the Dresden ISFSI, even though the
CBS variant basket design is not part of the approved CoC No. 1014, Amendment No. 8,
Revision No. 1. According to Constellation, the exemption is in the public interest
because unloading fuel from already loaded canisters and not being able to load fuel into
dry storage in future loading campaigns would impact Constellations ability to offload
fuel from the Dresden reactor units, consequently impacting continued safe reactor
operation. The reflooding of the MPCs, removal of fuel assemblies, and replacement into
a different MPC would result in additional doses and handling operations with no added
safety benefit. In addition, future loading campaigns would need to be delayed until older
design canisters can be fabricated and delivered to the site.
Constellation stated that to unload already loaded MPC-68M-CBS or delay the
future loading campaigns would impact the ability to effectively manage the margin to full
core discharge capacity in the Dresden Unit 2 and Unit 3 spent fuel pools. The low spent
fuel pool capacity would make it difficult to refuel and present potential risks to fuel
handling operations during pre-and post-outage. In addition, a crowded spent fuel pool
would challenge the decay heat removal demand of the pool and increase the likelihood
of a loss of fuel pool cooling event and a fuel handling accident. Furthermore, Dresden
planned the cask loading campaigns years in advance based on availability of the
specialized workforce and equipment that is shared throughout the Constellation fleet.
These specialty resources support competing priorities including refueling outages,
loading campaigns, fuel pool cleanouts, fuel inspections, fuel handing equipment
upgrade and maintenance, fuel sipping, new fuel receipt, and crane maintenance and
upgrades. Any delays would have a cascading impact on other scheduled specialized
activities.
9 For the reasons described by Constellation 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, Constellation would have to unload MPC-68M-
CBS from the HI-STORM 100 Cask System at the Dresden ISFSI and reload into the
older design MPC-68M to restore compliance with terms, conditions, and specifications
of the CoC. This would subject onsite personnel to additional radiation exposure,
increase the risk of a possible fuel handling accident, and increase the risk of a possible
heavy load handling accident. Furthermore, the removed spent fuel would need to be
placed in the spent fuel pool until it can be loaded into another storage cask or remain in
the spent fuel pool if it is not permitted to be loaded into casks for future loading
campaigns. As described by Constellation, this scenario would affect Constellations
ability to effectively manage the spent pool capacity and reactor fuel offloading at
Dresden. In addition, the rescheduling of the specialized resources for the future loading
campaigns would impact the operations of Dresden and other Constellation sites.
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
10 proposed action. The environmental assessment and the finding of no significant impact
was published on April 1, 2024 (89 FR 22463).
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 Constellation 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 ongoing
storage of four MPC-68M-CBS in the HI-STORM 100 Cask System and future loading in
the HI-STORM 100 Cask System of one MPC -68M-CBS in May 2024 and four MPC-
68M-CBS in March 2025.
This exemption is effective upon issuance.
Dated: April 1, 2024.
For the Nuclear Regulatory Commission.
/RA/
Yoira K. Diaz-Sanabria, Chief, Storage and Transportation Licensing Branch, Division of Fuel Management, Office of Nuclear Material Safety, and Safeguards.
11