[Federal Register Volume 88, Number 198 (Monday, October 16, 2023)]
[Notices]
[Pages 71381-71383]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-22783]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-483; NRC-2023-0158]
Union Electric Company, dba Ameren Missouri; Callaway Plant; Unit
No. 1
AGENCY: Nuclear Regulatory Commission.
ACTION: Exemption; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) has issued an
exemption in response to an exemption request from Union Electric
Company doing business as Ameren Missouri (the licensee) submitted by
letter dated October 12, 2022, as supplemented by letters dated
December 1, 2022, May 9, 2023, June 21, 2023, and August 3, 2023.
DATES: The exemption was issued on October 5, 2023.
ADDRESSES: Please refer to Docket ID NRC-2023-0158 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-2023-0158. Address
questions about Docket IDs in Regulations.gov to Stacy Schumann;
telephone: 301-415-0624; email: [email protected]. For technical
questions, contact the individual listed 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 Web-based ADAMS
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 request for
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the exemption was submitted by letter dated October 12, 2022 (ADAMS
Package Accession No. ML22285A115), as supplemented by letters dated
December 1, 2022 (ADAMS Package Accession No. ML22335A497); May 9, 2023
(ADAMS Package Accession No. ML23129A793); June 21, 2023 (ADAMS
Accession No. ML23172A145); and August 3, 2023 (ADAMS Package Accession
No. ML23215A196).
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: Mahesh Chawla, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, telephone: 301-415-8371; email: [email protected].
SUPPLEMENTARY INFORMATION: The text of the exemption is attached.
Dated: October 11, 2023.
For the Nuclear Regulatory Commission.
Mahesh L. Chawla,
Project Manager, Plant Licensing Branch 4, Division of Operating
Reactor Licensing, Office of Nuclear Reactor Regulation.
Attachment--Exemption
Nuclear Regulatory Commission
Docket No. 50-483
Union Electric Company Callaway Plant, Unit No. 1
Exemption
I. Background
Union Electric Company, doing business as (dba) as Ameren Missouri
(the licensee), is the holder of Renewed Facility Operating License No.
NPF-30, which authorizes operation of the Callaway Plant, Unit No. 1
(Callaway). 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
consists of a pressurized-water reactor (PWR) located in Callaway
County, Missouri.
II. Request/Action
By letter dated October 12, 2022 (Agencywide Documents Access and
Management System (ADAMS) Accession No. ML22285A115), as supplemented
by letters dated December 1, 2022; May 9, 2023; June 21, 2023; and
August 3, 2023 (ML22335A497, ML23129A793, ML23172A145, and ML23215A196,
respectively), Ameren Missouri, submitted a license amendment request
(LAR) for Callaway, proposing to load a limited number of Framatome
GAIA fuel assemblies starting in operating cycle 27 to obtain incore
performance data and acquire operational experience associated with the
GAIA fuel design. Pursuant to title 10 of the Code of Federal
Regulations (10 CFR) section 50.12, ``Specific exemptions,'' the
licensee also requested an exemption from certain requirements of 10
CFR 50.46, ``Acceptance criteria for emergency core cooling systems,''
and 10 CFR part 50, appendix K, ``ECCS [Emergency Core Cooling Systems]
Evaluation Models,'' for Callaway in enclosure 2 to the LAR dated
October 12, 2022.
This exemption request relates solely to the specific types of
cladding materials for which 10 CFR 50.46 and 10 CFR part 50, appendix
K, are expressly applicable, namely zircaloy and ZIRLOTM.
Since these regulations specifically apply only to zircaloy and
ZIRLOTM, an exemption would be required to apply them to
fuel clad with other materials, in this case Framatome M5[supreg].
Therefore, the licensee has requested such an exemption to support the
introduction of Framatome GAIA fuel with the M5[supreg] cladding. The
proposed request would not exempt Callaway from requirements of 10 CFR
50.46 or 10 CFR part 50, appendix K, regarding acceptance criteria,
evaluation model features and documentation, reporting of changes or
errors, etc.
This exemption request is specific to the M5[supreg] cladding
material exemption request only. The technical analysis necessary to
support proposed loading of a limited number of Framatome GAIA fuel
assemblies starting in operating cycle 27 is documented in the safety
evaluation (SE) for the related LAR (ML23240A369).
III. Discussion
Pursuant to 10 CFR 50.12, the licensee requested an exemption from
the requirements of 10 CFR 50.46, and appendix K to 10 CFR part 50. The
proposed exemption request would permit application of the requirements
of 10 CFR 50.46 and appendix K to 10 CFR part 50 to fuel rods clad with
M5[supreg] at Callaway.
The technical basis for the use of fuel clad with M5[supreg] in
PWRs is documented in Topical Report (TR) BAW-10227P-A, Revision 1,
``Evaluation of Advanced Cladding and Structural Material (M5) in PWR
Reactor Fuel,'' dated June 2003 (ADAMS Package No. ML15162B043). This
TR describes Framatome's evaluation for the use of the M5[supreg] alloy
in PWR fuel assemblies as a replacement for Zircaloy-4. This TR
discusses material properties of M5, as well as its behavior under
normal operation, anticipated transients, and postulated accident
conditions.
The regulation in 10 CFR 50.46(a)(1)(i) states, in part:
Each boiling or pressurized light-water nuclear power reactor
fueled with uranium oxide pellets within cylindrical zircaloy or
ZIRLO cladding must be provided with an emergency core cooling
system (ECCS) that must be designed so that its calculated cooling
performance following postulated loss-of-coolant accidents conforms
to the criteria set forth in paragraph (b) of this section. ECCS
cooling performance must be calculated in accordance with an
acceptable evaluation model and must be calculated for a number of
postulated loss-of-coolant accidents of different sizes, locations,
and other properties sufficient to provide assurance that the most
severe postulated loss-of-coolant, accidents are calculated.
Since 10 CFR 50.46 specifically refers to fuel with zircaloy or
ZIRLOTM cladding, its application to fuel clad with
materials other than zircaloy or ZIRLOTM requires an
exemption from this section of the regulations.
Paragraph I.A.5, ``Metal--Water Reaction Rate,'' of appendix K to
10 CFR part 50 states, in part:
The rate of energy release, hydrogen generation, and cladding
oxidation from the metal/water reaction shall be calculated using
the Baker-Just equation (Baker, L., Just, L.C., ``Studies of Metal
Water Reactions at High Temperatures, III. Experimental and
Theoretical Studies of the Zirconium-Water Reaction,'' [Argonne
National Laboratory] ANL-6548, page 7, May 1962).
The requirement for using the Baker-Just equation in appendix K-
conformant loss-of-coolant accident (LOCA) evaluation models presume
use of zircaloy- or ZIRLOTM-clad fuel rods. Therefore,
application of 10 CFR part 50, appendix K to cladding materials other
than zircaloy or ZIRLOTM also requires an exemption.
Pursuant to 10 CFR 50.12, the Commission may grant exemption from
requirements of the regulations in 10 CFR part 50 provided that (1) the
exemption is authorized by law, (2) the exemption will not present an
undue risk to the public health and safety, (3) the exemption is
consistent with the common defense and security, and (4) special
circumstances, as defined in 10 CFR 50.12(a)(2), are present. The
licensee's submittal identifies that the special circumstance
associated with its exemption request is that restricting application
of 10 CFR 50.46 and appendix K to 10 CFR part 50 to fuels
[[Page 71383]]
clad with only zircaloy or ZIRLOTM is not necessary to
achieve the purpose of these regulations.
A. The Exemption Is Authorized by Law
The NRC has authority under 10 CFR 50.12 to grant exemptions from
the requirements of 10 CFR part 50 upon demonstration of proper
justification. The fuel that will be irradiated at Callaway is clad
with a zirconium-based alloy that is not expressly within the scope of
10 CFR 50.46 and 10 CFR part 50, appendix K. However, the NRC staff
considers all other aspects of these regulations (e.g., acceptance
criteria, prescribed methods, reporting requirements) applicable to the
M5[supreg] cladding material, and the licensee states that it will
ensure that these regulations are satisfied for operation with fuel
clad with M5[supreg]. As discussed below, the NRC staff determined that
special circumstances exist, which support granting the proposed
exemption. Furthermore, granting the exemption would not result in a
violation of the Atomic Energy Act of 1954, as amended, or the
Commission's regulations. Therefore, the exemption is authorized by
law.
B. The Exemption Presents No Undue Risk to Public Health and Safety
As summarized in the staff's safety evaluation supporting this
exemption request (ML23234A152 (Enclosure 2)), the NRC-approved Topical
Report BAW-10227P-A, Revision 1, which concerns the properties of the
M5[supreg] alloy, provides assurance that predicted chemical, thermal,
and mechanical characteristics of M5[supreg]-alloy cladding are
acceptable under normal operation, anticipated transients, and
postulated accidents. The NRC staff finds that by utilizing the methods
and properties in NRC-approved TR (i.e., BAW-10227P-A), the licensee
meets the acceptance criteria and analytical methods in 10 CFR 50.46
and appendix K to 10 CFR part 50, and thus, ensures acceptable safety
margins for fuel clad with M5[supreg] that are consistent with those
the NRC has established for zircaloy and ZIRLOTM. Callaway
cores involving M5[supreg] cladding will continue to be subject to the
operating limits specified in the technical specifications (TSs) and
core operating limits report. Thus, granting this exemption request
does not pose undue risk to public health and safety.
C. The Exemption Is Consistent With the Common Defense and Security
The proposed exemption will allow the licensee to use an enhanced
fuel rod cladding material relative to the zircaloy material for which
the requirements of 10 CFR 50.46 and 10 CFR part 50, appendix K were
originally established. In addition to its review of the exemption
request, the NRC staff has evaluated all licensing-basis changes
necessary to support loading fuel clad with M5[supreg] in a separate SE
for the related license amendment request for fuel transition. Based on
these reviews, the NRC staff concludes that the use of M5[supreg] fuel
rod cladding at Callaway will not significantly affect plant operations
and is therefore consistent with the common defense and security.
D. Special Circumstances
Neither 10 CFR 50.46 nor 10 CFR part 50, appendix K explicitly
applies to fuel clad with M5[supreg]. However, the underlying purpose
of 10 CFR 50.46 and 10 CFR part 50, appendix K is to provide
requirements capable of ensuring adequate core cooling following the
most limiting postulated loss-of-coolant accident. As discussed above,
Framatome has demonstrated in an NRC-approved TR (i.e., BAW-10227P-A)
that application of the acceptance criteria and analytical methods
required in 10 CFR 50.46 and 10 CFR part 50, appendix K to fuel clad
with M5[supreg] is acceptable. The licensee stated in the exemption
request that the core reload safety analyses will be used to confirm on
a cycle-specific basis that there is no adverse impact on ECCS
performance for Callaway. Therefore, strict application of the
material-specific requirements for fuel cladding in 10 CFR 50.46 and 10
CFR part 50, appendix K is not necessary to achieve the underlying
purpose of ensuring adequate core cooling in this instance.
Furthermore, granting an exemption to allow application of the balance
of these regulations to fuel clad with M5[supreg] at Callaway would be
consistent with the underlying regulatory purpose.
E. Supplemental Information
For more technical details, refer to the SE associated with this
exemption under ML23234A152 (Enclosure 2).
F. Environmental Considerations
As discussed in the SE associated with this exemption, the NRC
staff determined that the exemption discussed herein meets the
eligibility criteria for the categorical exclusion set forth in 10 CFR
51.22(c)(9) because it is related to a requirement concerning the
installation or use of facility components located within the
restricted area, as defined in 10 CFR part 20, and the granting of this
exemption involves: (i) no significant hazards consideration, (ii) no
significant change in the types or a significant increase in the
amounts of any effluents that may be released offsite, and (iii) no
significant increase in individual or cumulative occupational radiation
exposure. Therefore, in accordance with 10 CFR 51.22(b), no
environmental impact statement or environmental assessment need be
prepared in connection with the NRC's consideration of this exemption
request.
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12, the exemption is authorized by law, 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 grants Union Electric Company dba
Ameren Missouri a one-time exemption from the requirements of 10 CFR
50.46 and 10 CFR part 50, appendix K. The proposed exemption request
would permit application of the requirements of 10 CFR 50.46 and
appendix K to fuel rods clad with M5[supreg] at Callaway. As stated
above, this exemption relates solely to the cladding material specified
in these regulations.
Dated at Rockville, Maryland, this 5th day of October, 2023
For the Nuclear Regulatory Commission.
Bo M. Pham,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. 2023-22783 Filed 10-13-23; 8:45 am]
BILLING CODE 7590-01-P