[Federal Register Volume 81, Number 149 (Wednesday, August 3, 2016)]
[Notices]
[Pages 51218-51220]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-18375]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-280 and 50-281 NRC-2016-0105]
Virginia Electric Power Company; Surry Power Station, Unit Nos. 1
and 2; Use of AREVA's M5[supreg] Alloy Fuel Rod Cladding Material
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 September 30, 2016, request from Virginia
Electric Power Company (Dominion or the licensee) in order to use
AREVA's M5[supreg] alloy fuel rod cladding material at Surry Power
Station, Unit Nos. 1 and 2 (SPS).
DATES: The exemption was issued on July 27, 2016.
ADDRESSES: Please refer to Docket ID NRC-2016-0105 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-2016-0105. Address
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; 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: Karen R. Cotton, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001; telephone: 301-415-1438, email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Background
Dominion is the holder of Facility Operating License Nos. DPR-32
and DPR-37, which authorize operation of SPS. The licenses provide,
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 two pressurized-water reactors (PWR)
located in Surry County, Virginia.
II. Request/Action
Pursuant to Sec. 50.12 of title 10 of the Code of Federal
Regulations (10 CFR), ``Specific exemptions,'' the licensee has
requested, by letter dated September 30, 2015 (ADAMS Accession No.
ML15282A036), an exemption from 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's M5[supreg] alloy. The
regulations in 10 CFR 50.46 require that the calculated cooling
performance following postulated loss-of-coolant accidents (LOCAs) at
reactors fueled with zircaloy or ZIRLOTM cladding conforms
to the criteria set forth in 10 CFR 50.46(b). In addition, 10 CFR part
[[Page 51219]]
50, appendix K, requires, in part, 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 zircaloy or ZIRLOTM materials
that have different chemical compositions from AREVA's M5[supreg]
alloy. As written, these regulations presume only the use of zircaloy
or ZIRLOTM fuel rod cladding and do not contain provisions
for use of fuel rods with other cladding materials. Therefore, an
exemption from the requirements of 10 CFR 50.46 and 10 CFR part 50,
appendix K, is needed to support the use of a different fuel cladding
material. Accordingly, the licensee requested an exemption that would
allow the use of fuel rods clad with AREVA's M5[supreg] alloy to be
loaded into the SPS reactor cores as non-limiting lead test assemblies
(LTAs) in up to eight locations.
III. Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its own initiative, grant exemptions from
the requirements of 10 CFR part 50 when the exemptions are authorized
by law, will not present an undue risk to public health or safety, and
are consistent with the common defense and security. However, 10 CFR
50.12(a)(2) states that the Commission will not consider granting an
exemption unless special circumstances are present as set forth in 10
CFR 50.12(a)(2). Under 10 CFR 50.12(a)(2)(ii), special circumstances
are present when application of the regulation in the particular
circumstances would not serve, or 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 10 CFR part 50,
appendix K, is to establish acceptance criteria for ECCS performance to
provide reasonable assurance of safety in the event of a LOCA. The
special circumstance that necessitates the request for exemption to 10
CFR 50.46 and 10 CFR 50, appendix K, is that neither of these
regulations explicitly allows the use of AREVA's M5[supreg] alloy fuel
rod cladding material. The ultimate objective of 10 CFR 50.46 is to
ensure that nuclear power reactors fueled with uranium oxide pellets
within zircaloy or ZIRLOTM cladding must be provided with an
ECCS that is designed to provide core cooling following a postulated
LOCA. AREVA NP, in its NRC-approved Topical Report BAW-10227-A,
``Evaluation of Advanced Cladding and Structural Material (M5) in PWR
Reactor Fuel,'' February 2000 (ADAMS Accession No. ML003686365), has
demonstrated that the effectiveness of the ECCS will not be affected by
a change from zircaloy or ZIRLOTM clad fuel to fuel rods
clad with AREVA's M5[supreg] alloy. Normal reload safety analyses will
confirm that there is no adverse impact on ECCS performance.
The objective of 10 CFR 50.46(b)(2) and (b)(3), and 10 CFR part 50,
appendix K I.A.5, is to ensure that cladding oxidation and hydrogen
generation are appropriately limited during a LOCA and conservatively
accounted for in the ECCS evaluation model. Appendix K of 10 CFR part
50 requires that the Baker-Just equation be used in the ECCS evaluation
model to determine the rate of energy release, cladding oxidation, and
hydrogen generation. AREVA NP has shown in an appendix of Topical
Report BAW-10227-A that the Baker-Just model is conservative in all
post-LOCA scenarios with respect to the use of AREVA's M5[supreg] alloy
fuel rod cladding material.
Based on the regulatory review of the exemption request, the NRC
staff concludes that the intent of 10 CFR 50.46 and 10 CFR part 50,
appendix K, will continue to be satisfied for the planned operation of
SPS with AREVA's M5[supreg] alloy fuel rod cladding material used for
non-limiting LTAs and the special circumstance required by 10 CFR
50.12(a)(2)(ii) for granting of an exemption exists.
B. Authorized by Law
This exemption would allow the use of fuel rods clad with AREVA's
M5[supreg] alloy in up to eight fuel assemblies at SPS. The regulations
in 10 CFR 50.12 allow the NRC to grant exemptions from the requirements
of 10 CFR part 50 provided that the exemptions are authorized by law.
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. Therefore,
the exemption is authorized by law.
C. No Undue Risk to Public Health and Safety
The provisions of 10 CFR 50.46 establish acceptance criteria for
ECCS performance. Topical Report BAW-10227-A contains the justification
to use AREVA's M5[supreg] alloy fuel rod cladding material, a
proprietary variant of Zr1Nb, to replace Zircaloy-4 in the construction
of fuel assembly components such as fuel rod cladding, guide tubes, and
spacer grids. This justification is required to support the request by
Dominion for an exemption to 10 CFR 50.46 to permit the use of AREVA's
M5[supreg] alloy fuel rod cladding material, in addition to Zircaloy-4
and ZIRLOTM. AREVA's M5[supreg] alloy is an AREVA NP
proprietary material composed of 1.0 percent niobium, 0.125 percent
oxygen, and the balance zirconium. AREVA's M5[supreg] alloy fuel rod
cladding provides improved performance in fuel cladding corrosion and
hydrogen pickup.
An AREVA NP LOCA evaluation showed compliance with 10 CFR 50.46.
Topical Report BAW-10227-A has addressed all of the important aspects
of AREVA's M5[supreg] alloy fuel rod cladding material with respect to
ECCS performance requirements, as follows:
Since the material properties of AREVA's M5[supreg] alloy
are similar to those of zirconium-based materials, the NRC staff found
it appropriately conservative to apply the criteria in 10 CFR 50.46 and
10 CFR part 50, appendix K.
Material properties of AREVA's M5[supreg] alloy, including
cladding thermal conductivity, cladding creep, clad swelling, rupture
deformation, and temperature, were found to be very similar to those of
Zircaloy-4.
The retention of the Baker-Just equation for the
calculation of metal-water reaction rate specified in 10 CFR part 50,
appendix K, is justified to be suitably conservative.
Based on the NRC staff's evaluation of the exemption request, the
staff concludes that the intent of 10 CFR 50.46 and 10 CFR part 50,
appendix K, will continue to be satisfied for the planned operation of
SPS, with AREVA's M5[supreg] alloy fuel rod cladding material used in
up to eight non-limiting LTAs. The probability of postulated accidents
is not increased. Also, based on the NRC staff's evaluation of the
exemption request, the consequences of postulated accidents are not
increased. Therefore, there is no undue risk to public health and
safety due to using M5[supreg] alloy fuel cladding and fuel assembly
material in up to eight non-limiting LTAs.
D. Consistent With the Common Defense and Security
The proposed exemption would allow the use of AREVA's M5[supreg]
alloy fuel rod cladding material at SPS. This change to the plant
configuration is adequately controlled by technical specification
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requirements and is not related to security issues. Because the common
defense and security is not impacted by this exemption, the exemption
is consistent with the common defense and security.
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12(a), the exemption is authorized by law, will not present an undue
risk to the public health and safety, is consistent with the common
defense and security, and that special circumstances are present to
warrant issuance of the exemption. Therefore, the Commission hereby
grants SPS an exemption from the requirements of 10 CFR 50.46 and 10
CFR part 50, appendix K, paragraph I.A.5, to allow the use of AREVA's
M5[supreg] alloy fuel rod cladding material in up to eight non-limiting
LTAs at SPS.
Pursuant to 10 CFR 51.32, an environmental assessment and finding
of no significant impact related to this exemption was published in the
Federal Register on May 31, 2016 (81 FR 34382). Based upon the
environmental assessment, the Commission has determined that issuance
of this exemption will not have a significant effect on the quality of
the human environment.
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 27th day of July 2016.
For the Nuclear Regulatory Commission.
Anne T. Boland,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. 2016-18375 Filed 8-2-16; 8:45 am]
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