81 FR 24900 - Florida Power & Light Company; St. Lucie Plant, Unit No. 2

NUCLEAR REGULATORY COMMISSION

Federal Register Volume 81, Issue 81 (April 27, 2016)

The U.S. Nuclear Regulatory Commission (NRC) is issuing an exemption in response to a December 30, 2014, request from Florida Power & Light Company for the use of a different fuel rod cladding material (AREVA M5[supreg]).

[Federal Register Volume 81, Number 81 (Wednesday, April 27, 2016)]
[Notices]
[Pages 24900-24903]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-09851]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-389; NRC-2016-0085]


Florida Power & Light Company; St. Lucie Plant, Unit No. 2

AGENCY: Nuclear Regulatory Commission.

ACTION: Exemption; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing an 
exemption in response to a December 30, 2014, request from Florida 
Power & Light Company for the use of a different fuel rod cladding 
material (AREVA M5[supreg]).

ADDRESSES: Please refer to Docket ID NRC-2016-0085 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 Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0085. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact 
the individuals 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 (if it is available 
in ADAMS) is provided the first time that it is mentioned in this 
document.
     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: Perry H. Buckberg; telephone: 301-415-
1383; email: [email protected]; or Robert L. Gladney; telephone: 
301-415-1022; email: [email protected]. Both are staff of the 
Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001.

[[Page 24901]]

I. Background

    Florida Power & Light Company (the licensee) is the holder of 
Renewed Facility Operating License No. NPF-16, which authorizes 
operation of the St. Lucie Plant, Unit No. 2 (PSL-2). 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

    Pursuant to Sec.  50.12, ``Specific exemptions,'' of title 10 of 
the Code of Federal Regulations (10 CFR), the licensee, by letter dated 
December 30, 2014 (ADAMS Accession No. ML15002A091), 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 the AREVA M5[supreg] zirconium 
alloy in future core reload applications for PSL-2. 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 M5[supreg] zirconium alloy. The licensee 
requested the exemption because these regulations do not have 
provisions for the use of fuel rods clad in a material other than 
Zircaloy or ZIRLO\TM\. Since the material designations of M5[supreg] 
zirconium alloy are different from the designations for Zircaloy or 
ZIRLO\TM\, a plant-specific exemption is required to support the reload 
applications for PSL-2.
    The exemption request relates solely to the cladding material 
specified in these regulations (i.e., fuel rods with Zircaloy or 
ZIRLO\TM\ cladding material). In its letter dated December 30, 2014, 
the licensee stated that this exemption was requested in order, ``to 
allow the use of a zirconium alloy other than Zircaloy or [ZIRLO\TM\] 
for fuel cladding material at St. Lucie Unit 2.'' 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 
M5[supreg] zirconium alloy fuel rod cladding material.
    In addition to the exemption request in the letter dated December 
30, 2014, the licensee also requested an amendment to revise the 
Technical Specifications (TSs) to allow for the use of AREVA fuel at 
PSL-2. The NRC staff has addressed the requested amendment in separate 
correspondence dated April 19, 2016 (ADAMS Accession No. ML16063A121).

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 directly 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] 
zirconium-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 for 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 fuel rods clad with the AREVA 
M5[supreg] fuel rod cladding material in future core reload 
applications for PSL-2. Section 50.12 of 10 CFR 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 
granting the licensee's proposed 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 50.46 of 10 CFR requires that each boiling or pressurized 
light-water nuclear power reactor fueled with uranium oxide pellets 
within cylindrical Zircaloy or ZIRLO\TM\ 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 that section. The underlying purpose of 10 
CFR 50.46 is to establish acceptance criteria for adequate ECCS 
performance at nuclear reactors.
    Framatome Cogema Fuels (AREVA) submitted topical report BAW-10227P-
A, Revision 0, ``Evaluation of Advanced Cladding and Structural 
Material (M5[supreg]) in PWR Reactor Fuel,'' to the NRC for review and 
approval by letter dated September 30, 1997. The NRC staff documented 
its approval of BAW-10227P-A, Revision 0 in a safety evaluation (SE) 
dated February 4, 2000 (ADAMS Accession No. ML003681490) and concluded 
that 10 CFR 50.46 and 10 CFR part 50, Appendix K criteria are 
applicable to M5[supreg] fuel cladding, subject to compliance with 
specified burnup conditions. The NRC-accepted version of BAW-10227P-A, 
Revision 0 was submitted to the NRC by letter dated February 11, 2000 
(ADAMS Accession No. ML003685828). BAW-10227P-A, Revision 1, dated June 
2003, as noted by letter dated April 19, 2004 (ADAMS Accession No. 
ML15162B047), is a subsequent revision to BAW-10227P-A, Revision 0 and 
incorporated the portion of the NRC's approval provided in the NRC SE 
for BAW-10186P-A, Revision 1, Supplement 1, ``Extended Burnup 
Evaluation,'' dated June 18, 2003 (ADAMS Accession No. ML031700090), in 
which the applicable restrictions on burnup were removed. Additionally, 
in

[[Page 24902]]

an SE dated May 5, 2004 (ADAMS Accession No. ML041260560), the NRC 
staff approved topical report BAW-10240(P), ``Incorporation of M5 
Properties in Framatome ANP [AREVA] Approved Methods,'' which further 
addressed M5[supreg] material properties with respect to LOCA 
applications and included specified conditions.
    The specific conditions that address the use of M5[supreg] under 
approved methods that were provided in the SE for BAW-10240(P) are: (1) 
The corrosion limit, as predicted by the best-estimate model, will 
remain below 100 microns for all locations of the fuel; (2) all of the 
conditions listed in the NRC SEs for all AREVA methodologies used for 
M5[supreg] fuel analysis will continue to be met; (3) all AREVA 
methodologies will be used only within the range for which M5[supreg] 
data was acceptable and for which the verifications discussed in the 
applicable topical reports were performed; and (4) the burnup limit for 
implementation of M5[supreg] is 62 gigawatt-days per metric ton 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 SEs stated in condition (2) are incorporated as restrictions 
in AREVA design procedures and guidelines that will control the core 
reload designs for PSL-2, which are also verified 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 design procedures and guidelines that will 
control the core reload designs for PSL-2, which are also verified for 
each reload as required by the COLR. Finally, the burnup limit stated 
in condition (4) is currently part of AREVA's design processes (as 
stated by the licensee), and is also verified as part of the cycle-
specific reload analysis as required by the COLR.
    In the exemption granted for PSL, Unit No. 1, for the application 
and use of AREVA M5[supreg] fuel rod cladding material, dated March 31, 
2014 (ADAMS Accession No. ML14064A125), the NRC staff described the 
applicable results from the LOCA research program completed at the 
Argonne National Laboratory. The results showed that cladding corrosion 
and associated hydrogen pickup had a significant impact on post-quench 
ductility. The research also provided further evidence of favorable 
corrosion and hydrogen pickup characteristics of M5[supreg] as compared 
with standard Zircaloy and that, due to its favorable hydrogen pickup, 
fuel rods with M5[supreg] zirconium-based alloy cladding are less 
susceptible to hydrogen-enhanced beta layer embrittlement, a new 
embrittlement mechanism. In addition, the exemption documented 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 and that the acceptance criteria 
within 10 CFR 50.46 remain valid for the M5[supreg] alloy material. As 
a result, the NRC staff found that 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 met if an 
exemption were granted to allow those criteria to apply to M5[supreg] 
clad fuel. This conclusion remains valid for an exemption for PSL-2 for 
the application and use of AREVA M5[supreg] fuel rod cladding material.
    In addition, as stated by the licensee in its application, ``FPL 
[Florida Power & Light Company], in conjunction with AREVA NP Inc. 
(AREVA), will utilize NRC[-]approved methods for the reload design 
process, for PSL-2 reload cores containing M5[supreg] fuel rod 
cladding, to ensure safety analysis limits are met for operation within 
the operating limits specified in the Technical Specifications.'' The 
licensee also stated that it will ``ensure compliance with the 
respective acceptance criteria'' and that ``the intent of 10 CFR 50.46 
and 10 CFR 50, Appendix K will continue to be satisfied.'' Therefore, 
for the reasons stated above, granting the exemption request will 
ensure that the underlying purpose of the rule is achieved for PSL-2.
    Paragraph I.A.5 of Appendix K to 10 CFR part 50 states that the 
rate of energy release, hydrogen concentration, and cladding oxidation 
from the metal-water reaction shall be calculated using the Baker-Just 
equation. 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 stated 
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 PSL-2.
    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 part 50, Appendix K, methods, the NRC 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 PSL-2. 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. In its letter dated December 30, 2014, the licensee stated 
that all the requirements and acceptance criteria will be maintained 
and that it would continue to handle and control special nuclear 
material in the fuel product in accordance with its approved 
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 has determined that this exemption does not 
impact common defense and security and 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 be 
prepared in connection with the NRC's consideration of this exemption 
request. The basis for the NRC staff's determination is discussed as 
follows with an evaluation against each 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 below:
    1. Does the proposed exemption involve a significant increase in 
the

[[Page 24903]]

probability or consequences of an accident previously evaluated?
    The proposed changes for PSL-2 revise TS 5.3.1 to include 
M5[supreg] cladding, delete the linear heat rate surveillance 
requirement with W(z) in TS 4.2.1.3, and include previously approved 
AREVA topical reports in the list of COLR methodologies in TS 6.9.1.11. 
[Another] change is in TS License Condition 3.N, which is related to 
future analysis of the current fuel and is considered an administrative 
change, all as a result of changing the fuel supplier.
    The fuel assembly design is not an initiator to any accident 
previously evaluated. Therefore, there is no significant increase in 
the probability of any accident previously evaluated. However, the fuel 
design parameters and the correlations used in the analyses supporting 
the operation of PSL-2 with the new proposed AREVA fuel are dependent 
on the fuel assembly design. All the analyses, potentially impacted by 
the fuel design, have been re-analyzed using the correlations and the 
methodology applicable to the proposed fuel design and previously 
approved by the NRC for similar applications. There are no changes to 
any limits specified in the TSs. M5[supreg] cladding to be used in the 
proposed AREVA fuel design has been previously approved by the NRC for 
PWR applications, including the St. Lucie Plant, Unit No. 1. The core 
design peaking factors remain unchanged from the current analyses 
values, except for the large break LOCA, which is shown to meet all the 
10 CFR 50.46 criteria with the increased peak linear heat rate limit.
    Therefore, the proposed changes do 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 new or different accidents result from utilizing the proposed 
AREVA CE [Combustion Engineering] 16x16 fuel design [and M5[supreg] 
cladding]. Other than the fuel design change, the proposed exemption 
does not involve a physical alteration of the plant or plant systems 
(i.e., no new or different type of equipment will be installed which 
would create a new or different kind of accident). The change to the 
linear heat rate surveillance requirement, when operating on excore 
detector monitoring system, and the use of M5[supreg] cladding do not 
affect or create any accident initiator. There is no change to the 
methods governing normal plant operation and the changes do not impose 
any new or different operating requirements. The core monitoring system 
remains unchanged.
    Therefore, the proposed change does not create the possibility of a 
new or different kind of accident from any accident previously 
evaluated.
    3. Does the proposed exemption involve a significant reduction in a 
margin of safety?
    The changes proposed in this exemption are related to the fuel 
design with M5[supreg] cladding and the methodology supporting the 
analysis of accidents impacted by the fuel design change. The analysis 
methods used are previously approved by the NRC for similar 
applications. The change to the surveillance requirement for the linear 
heat rate does not change any accident analysis requirements. The fuel 
design limits related to the DNBR [departure from nucleate boiling 
ratio] and fuel centerline melt remain consistent with the limits 
previously approved for the proposed fuel design change. The 
overpressure limits for the reactor coolant system integrity and the 
containment integrity remain unchanged. All of the analyses performed 
to support the fuel design change meet all applicable acceptance 
criteria. The LOCA analyses, with the peak linear heat rate limit 
increase, continue to meet all of the applicable 10 CFR 50.46 
acceptance criteria, and thus the proposed changes do not affect margin 
of safety for any accidents previously evaluated.
    Therefore, the proposed changes do 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 PSL-2 reactor. M5[supreg] has essentially the 
same properties as the currently licensed Zircaloy fuel rod 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 satisfied.
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 PSL-2 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 satisfied.

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, as 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 use of M5[supreg] fuel 
rod cladding material at PSL-2.
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 19th of April, 2016.

    For the Nuclear Regulatory Commission.
Anne T. Boland,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 2016-09851 Filed 4-26-16; 8:45 am]
 BILLING CODE 7590-01-P