[Federal Register Volume 79, Number 68 (Wednesday, April 9, 2014)]
[Notices]
[Pages 19659-19662]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-07972]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-335; NRC-2014-0076]
Exemption for Florida Power & Light Company; St. Lucie Plant,
Unit 1
AGENCY: Nuclear Regulatory Commission.
ACTION: Exemption; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is granting an
[[Page 19660]]
exemption in response to a May 10, 2013, request from Florida Power &
Light Company for an exemption for the use of a different fuel rod
cladding material (AREVA M5[supreg]).
ADDRESSES: Please refer to Docket ID NRC-2014-0076 when contacting the
NRC about the availability of information regarding this document. You
may access publicly-available information related to this action by the
following methods:
Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2014-0076. Address
questions about NRC dockets to Carol Gallagher; telephone: 301-287-
3422; 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 http://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``ADAMS Public Documents'' and
then 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, 301-415-4737, or by email to [email protected]. The
ADAMS accession number for each document referenced in this document
(if that document is available in ADAMS) is provided the first time
that a document is referenced.
NRC's PDR: You may examine and purchase copies of public
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852.
FOR FURTHER INFORMATION CONTACT: Lisa M. Regner, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington DC
20555-0001; telephone: 301-415-1906; email: [email protected].
I. Background
Florida Power & Light Company (the licensee) is the holder of
Renewed Facility Operating License No. DPR-67, which authorizes
operation of the St. Lucie Plant, Unit 1. The license provides, among
other things, that the facility is subject to all rules, regulations,
and orders of the NRC now or hereafter in effect. The facility consists
of a pressurized-water reactor (PWR) located in St. Lucie County,
Florida.
II. Request/Action
In accordance with Sec. 50.12, of Title 10 of the Code of Federal
Regulations (10 CFR), ``Specific exemptions,'' the licensee, by letter
dated May 10, 2013 (ADAMS Accession No. ML13135A008), requested an
exemption from the requirements of 10 CFR 50.46, ``Acceptance criteria
for emergency core cooling systems [ECCS] for light-water nuclear power
reactors,'' and 10 CFR Part 50, Appendix K, ``ECCS Evaluation Models,''
to allow the use of fuel rods clad with AREVA M5[supreg] alloy for
future reload applications. The regulations in 10 CFR 50.46 contain
acceptance criteria for the ECCS for reactors fueled with zircaloy or
ZIRLO\TM\ fuel rod cladding material. In addition, Appendix K to 10 CFR
Part 50 requires that the Baker-Just equation be used to predict the
rates of energy release, hydrogen concentration, and cladding oxidation
from the metal/water reaction. The Baker-Just equation assumes the use
of a zirconium alloy, which is a material different from the AREVA
M5[supreg] material. The licensee requested the exemption because these
regulations do not have criteria for the use of fuel rods clad in a
material other than zircaloy or ZIRLO\TM\. Because the material
specifications of M5[supreg] differ from the specification for zircaloy
or ZIRLO\TM\, a plant-specific exemption is required to support the
reload applications for St. Lucie Plant Unit 1.
The exemption request relates solely to the cladding material
specified in these regulations (i.e., fuel rods with zircaloy or
ZIRLO\TM\ cladding material). This exemption would provide for the
application of the acceptance criteria of 10 CFR 50.46 and Appendix K
to 10 CFR Part 50 to fuel assembly designs using AREVA M5[supreg] fuel
rod cladding material.
III. Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person, grant exemptions from the requirements of 10 CFR
Part 50, which are authorized by law, will not present an undue risk to
the public health and safety, and are consistent with the common
defense and security. Paragraph (a)(2)(ii) of 10 CFR 50.12 states that
the Commission will not consider granting an exemption unless special
circumstances are present, such as when application of the regulation
in the particular circumstance is not necessary to achieve the
underlying purpose of the rule.
A. Special Circumstances
Special circumstances, in accordance with 10 CFR 50.12(a)(2)(ii),
are present whenever application of the regulation in the particular
circumstances is not necessary to achieve the underlying purpose of the
rule. The underlying purpose of 10 CFR 50.46 and Appendix K to 10 CFR
Part 50 is to establish acceptance criteria for ECCS performance. The
regulations in 10 CFR 50.46 and Appendix K are not expressly applicable
to M5[supreg] cladding material, because the M5[supreg] cladding
material is not specified in 10 CFR 50.46 or presumed in the Baker-Just
equation required by paragraph I.A.5 of 10 CFR Part 50, Appendix K. The
evaluations described in the following sections of this exemption,
however, show that the intent of the regulation is met, in that,
subject to certain conditions, the acceptance criteria are valid for
M5[supreg] zircaloy-based alloy cladding, the material is less
susceptible to embrittlement, and the Baker-Just equation
conservatively bounds scenarios following a loss of coolant accident
(LOCA) for rods with M5[supreg] cladding material. Thus, a strict
application of the rule (which would preclude the applicability of ECCS
performance acceptance criteria to, and the use of, M5[supreg] clad
fuel rods) is not necessary to achieve the underlying purposes of 10
CFR 50.46 and Appendix K of 10 CFR Part 50. The purpose of these
regulations is achieved through the application of the requirements to
the use of M5[supreg] fuel rod cladding material. Therefore, the
special circumstances required by 10 CFR 50.12(a)(2)(ii) for the
granting of an exemption exist.
B. The Exemption Is Authorized by Law
This exemption would allow the use of M5[supreg] fuel rod cladding
material for future reload applications at St. Lucie Plant, Unit 1.
Section 10 CFR 50.12 allows the NRC to grant exemptions from the
requirements of 10 CFR Part 50 provided that special circumstances are
present. The NRC staff determined that special circumstances exist to
grant the proposed exemption and that 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.
C. The Exemption Presents No Undue Risk to Public Health and Safety
Section 10 CFR 50.46 requires that each boiling or pressurized
light-water nuclear power reactor fueled with uranium oxide pellets
within
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cylindrical zircaloy or ZIRLO cladding must be provided with an ECCS
that must be designed so that its calculated cooling performance
following postulated LOCAs conforms to the criteria set forth in
paragraph (b) of this section. The underlying purpose of 10 CFR 50.46
is to establish acceptance criteria for ECCS performance at nuclear
power reactors. The NRC staff previously documented its approval of
AREVA topical report BAW-10227P, ``Evaluation of Advanced Cladding and
Structural Material (M5[supreg]) in PWR Reactor Fuel,'' in a safety
evaluation dated February 4, 2000 (ADAMS Accession No. ML003681490),
and concluded that the 10 CFR 50.46 and 10 CFR Part 50, Appendix K,
criteria are applicable to M5[supreg] fuel, subject to compliance with
specific conditions. The specific conditions that address the use of
M5[supreg] with respect to ECCS performance requirements are: (1) the
corrosion limit will remain below 100 microns for all locations of the
fuel; (2) all conditions listed in the NRC safety evaluations for AREVA
methodologies for M5[supreg] fuel analysis will continue to be met; (3)
AREVA methodologies will be used only within the range for which
M5[supreg] data was acceptable and for which the verifications
discussed in the topical reports were performed; and (4) the burnup
limit for implementation of M5[supreg] is 62 gigawatt-days per megaton
uranium metal (GWd/MTU). The staff determined that the licensee has
satisfied these conditions. The corrosion limit stated in condition (1)
is verified by the licensee for each reload as required by TS 6.9.1.11,
``Core Operating Limits Report [COLR].'' The conditions from NRC
approved safety evaluations stated in condition (2) are incorporated as
restrictions in AREVA procedures that control the core reload designs
which are also verified by the licensee for each reload as required by
the COLR. The restrictions on the use of AREVA methodologies stated as
condition (3) are also incorporated as restrictions in AREVA procedures
that control the core reload designs which are also verified for each
reload as required by the COLR. Finally, the burnup limit stated in
condition (4) is currently part of the St. Lucie Plant, Unit 1, COLR,
and is also verified as part of the reload analysis required by the
COLR.
The AREVA topical report BAW-10227P-A, which was submitted to the
NRC by letter dated February 11, 2000 (ADAMS Accession No.
ML003685828), demonstrates that M5[supreg] has essentially the same
properties as the current zircaloy cladding material and requires no
change in fuel rod dimensions. Subsequently, the NRC staff approved
topical report, BAW-10240P-A, ``Incorporation of M5 Properties in
Framatome ANP Approved Methods'' (dated May 5, 2004; ADAMS Accession
No. ML041260560), which further addressed M5[supreg] material
properties with respect to LOCA applications and reached similar
conclusions.
Based on the recently completed LOCA research program at Argonne
National Laboratory (ANL), the results showed that cladding corrosion
and associated hydrogen pickup had a significant impact on postquench
ductility. The research identified a new embrittlement mechanism
referred to as hydrogen-enhanced beta layer embrittlement. Pretest
characterization of irradiated M5[supreg] fuel cladding segments at ANL
provides further evidence of favorable corrosion and hydrogen pickup
characteristics of M5[supreg] as compared with standard zircaloy. Due
to its favorable hydrogen pickup, fuel rods with M5[supreg] zirconium-
based alloy cladding are less susceptible to this new embrittlement
mechanism.
Furthermore, ANL postquench ductility tests on un-irradiated and
irradiated M5[supreg] cladding segments demonstrate that the 10 CFR
50.46(b) acceptance criteria (i.e., 2200 degrees Fahrenheit and 17-
percent equivalent cladding reacted) remain conservative up to the
current burnup limit of 62 GWd/MTU. Information provided in the
previously approved M5[supreg] topical reports and recent ANL LOCA
research demonstrate that the acceptance criteria within 10 CFR 50.46
remain valid for the M5[supreg] alloy material, and thus the underlying
purpose of the rule--to maintain a degree of post-quench ductility in
the fuel cladding material through ECCS performance criteria--would be
served if an exemption were granted to allow those criteria to apply to
M5[supreg] clad fuel.
In addition, utilizing currently-approved LOCA models and methods
and consistent with technical specifications, the licensee will perform
an evaluation to ensure that the M5[supreg] fuel rods continue to
satisfy 10 CFR 50.46 acceptance criteria. Therefore, for the reasons
above, granting the exemption request will ensure that the underlying
purpose of the rule is achieved for St. Lucie Plant, Unit 1. Thus, a
strict application of the rule (which would prohibit the applicability
of ECCS performance acceptance criteria to M5[supreg] clad fuel rods)
is not necessary to achieve the underlying purpose of the rule.
Paragraph I.A.5 of Appendix K to 10 CFR Part 50 states that the
rates of energy, hydrogen concentration, and cladding oxidation from
the metal-water reaction shall be calculated using the Baker-Just
equation. Since the Baker-Just equation presumes the use of zircaloy
clad fuel, strict application of the rule would not permit use of the
equation for the advanced zirconium-based M5[supreg] alloy for
determining acceptable fuel performance. The underlying intent of this
portion of the appendix, however, is to ensure that the analysis of
fuel response to LOCAs is conservatively calculated. The approved AREVA
topical reports show that due to the similarities in the chemical
composition of the advanced zirconium-based M5[supreg] alloy and
zircaloy, the application of the Baker-Just equation in the analysis of
the M5[supreg] clad fuel rods will continue to conservatively bound all
post-LOCA scenarios. For the reasons above, granting the exemption
request will ensure that the Baker-Just equation can be applied to
M5[supreg] clad fuel and that the underlying purpose of the rule is
achieved for St. Lucie Plant, Unit 1. Thus, a strict application of the
rule (which would preclude the application of the Baker-Just equation)
is not necessary to achieve the underlying purpose of the rule.
Based upon results of metal-water reaction testing and mechanical
testing which ensure the applicability of 10 CFR 50.46 acceptance
criteria and 10 CFR 50 Appendix K methods, the staff finds it
acceptable to grant an exemption from the requirements of 10 CFR 50.46
and Appendix K to 10 CFR Part 50 to allow these regulations to apply
to, and enable the use of, fuel rods with M5[supreg] zirconium-based
alloy at St. Lucie Plant, Unit 1. Therefore, the exemption presents no
undue risk to public health and safety.
D. The Exemption Is Consistent With the Common Defense and Security
The licensee's exemption request is only to allow the application
of the aforementioned regulations to an improved fuel rod cladding
material that is not specified or presumed by the cited regulations. In
its letter dated May 10, 2013, the licensee stated that 10 CFR 50.46
and 10 CFR Part 50, Appendix K, requirements and acceptance criteria
will be maintained. The licensee is required to handle and control
special nuclear material in these assemblies in accordance with its
approved plant procedures. This change to the reactor core internals is
adequately controlled by NRC requirements and is not related to
security issues. Therefore, the NRC staff determined that this
exemption does not impact common defense and
[[Page 19662]]
security and thus, is consistent with the common defense and security.
E. Environmental Considerations
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 a facility component 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 to be
prepared in connection with the NRC's consideration of this exemption
request. The basis for the NRC staff's determination is discussed in
the following evaluation of the requirements in 10 CFR 51.22(c)(9)(i)-
(iii).
Requirements in 10 CFR 51.22(c)(9)(i)
The NRC staff evaluated the issue of no significant hazards
consideration, using the standards described in 10 CFR 50.92(c), as
presented as follows:
1. Does the proposed exemption involve a significant increase in
the probability or consequences of an accident previously evaluated?
No. The proposed exemption would allow the use of M5[supreg] fuel
rod cladding material in the St. Lucie Plant Unit 1 reactor core. The
NRC-approved topical reports, BAW-10227P-A and BAW-10240(P)(A), address
the M5[supreg] material and demonstrate that it has essentially the
same properties as currently licensed zircaloy. The fuel cladding
itself is not an accident initiator and does not affect accident
probability. Use of M5[supreg] fuel rod cladding material will continue
to meet all 10 CFR 50.46 acceptance criteria and, therefore, will not
increase the consequences of an accident. Therefore, the proposed
exemption does not involve a significant increase in the probability or
consequences of an accident previously evaluated.
2. Does the proposed exemption create the possibility of a new or
different kind of accident from any accident previously evaluated?
No. The use of M5[supreg] fuel rod cladding material will not
result in changes in the operation or configuration of the facility.
The NRC-approved topical reports BAW-10227P-A and BAW-10240(P)(A)
demonstrated that the material properties of M5[supreg] are similar to
those of zircaloy. The M5[supreg] fuel rod cladding material will
perform similarly to those fabricated from zircaloy, thus precluding
the possibility of the fuel cladding becoming an accident initiator and
causing a new or different type of accident. Therefore, the proposed
exemption does not create the possibility of a new or different kind of
accident from any previously evaluated.
3. Does the proposed exemption involve a significant reduction in a
margin of safety?
No. The proposed exemption does not involve a significant reduction
in a margin of safety because it has been demonstrated that the
material properties of the M5[supreg] material are not significantly
different from those of zircaloy. M5[supreg] is expected to perform
similarly to zircaloy for all normal operating and accident scenarios,
including both LOCA and non-LOCA scenarios. For LOCA scenarios, plant-
specific LOCA analyses using M5[supreg] properties demonstrate that the
acceptance criteria of 10 CFR 50.46 have been satisfied. Therefore, the
proposed exemption does not involve a significant reduction in a margin
of safety.
Based on the above, the NRC staff concludes that the proposed
exemption presents no significant hazards consideration under the
standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of
no significant hazards consideration is justified.
Requirements in 10 CFR 51.22(c)(9)(ii)
The proposed exemption would allow the use of M5[supreg] fuel rod
cladding material in the reactors. AREVA M5[supreg] material has
essentially the same properties as the currently licensed zircaloy
cladding. The use of the M5[supreg] fuel rod cladding material will not
significantly change the types of effluents that may be released
offsite, or significantly increase the amount of effluents that may be
released offsite. Therefore, the provisions of 10 CFR 51.22(c)(9)(ii)
are met.
Requirements in 10 CFR 51.22(c)(9)(iii)
The proposed exemption would allow the use of the M5[supreg] fuel
rod cladding material in the St. Lucie Plant, Unit 1 reactor core.
M5[supreg] has essentially the same properties as the currently used
zircaloy cladding. The use of the M5[supreg] fuel rod cladding material
will not significantly increase individual occupational radiation
exposure, or significantly increase cumulative occupational radiation
exposure. Therefore, the provisions of 10 CFR 51.22(c)(9)(iii) are met.
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12(a)(1), 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 required by 10
CFR 50.12(a)(2)(ii) are present. Therefore, the Commission hereby
grants the licensee an exemption from the requirements of 10 CFR 50.46
and Appendix K to 10 CFR Part 50, to allow the application of those
criteria to, and the use of, M5[supreg] fuel rod cladding material at
St. Lucie Plant Unit 1.
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 31st day of March 2014.
For the Nuclear Regulatory Commission.
Michele G. Evans,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. 2014-07972 Filed 4-8-14; 8:45 am]
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