Entergy Operations, Inc.; Arkansas Nuclear One, Unit 2; Exemption, 17384-17386 [E8-6630]
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17384
Federal Register / Vol. 73, No. 63 / Tuesday, April 1, 2008 / Notices
1. The title of the information
collection: NRC Form 536, ‘‘Operator
Licensing Examination Data.’’
2. Current OMB approval number:
3150–0131.
3. How often the collection is
required: Annually.
4. Who is required or asked to report:
All holders of operator licenses or
construction permits for nuclear power
reactors.
5. The number of annual respondents:
80.
6. The number of hours needed
annually to complete the requirement or
request: 80.
7. Abstract: NRC is requesting
renewal of its clearance to annually
request all commercial power reactor
licensees and applicants for an
operating license to voluntarily send to
the NRC: (1) Their projected number of
candidates for operator licensing initials
examinations; (2) the estimated dates of
the examinations; (3) if the examination
will be facility developed or NRC
developed, and (4) the estimated
number of individuals that will
participate in the Generic Fundamentals
Examination (GFE) for that calendar
year. Except for the GFE, this
information is used to plan budgets and
resources in regard to operator
examination scheduling in order to meet
the needs of the nuclear industry.
Submit, by June 2, 2008, comments
that address the following questions:
1. Is the proposed collection of
information necessary for the NRC to
properly perform its functions? Does the
information have practical utility?
2. Is the burden estimate accurate?
3. Is there a way to enhance the
quality, utility, and clarity of the
information to be collected?
4. How can the burden of the
information collection be minimized,
including the use of automated
collection techniques or other forms of
information technology?
A copy of the draft supporting
statement may be viewed free of charge
at the NRC Public Document Room, One
White Flint North, 11555 Rockville
Pike, Room O–1 F21, Rockville, MD
20852. OMB clearance requests are
available at the NRC worldwide Web
site: https://www.nrc.gov/public-involve/
doc-comment/omb/. The
document will be available on the NRC
home page site for 60 days after the
signature date of this notice.
Comments and questions about the
information collection requirements
may be directed to the NRC Clearance
Officer, Margaret A. Janney (T–5 F52),
U.S. Nuclear Regulatory Commission,
Washington, DC 20555–0001, by
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telephone at 301–415–7245, or by e-mail
to INFOCOLLECTS@NRC.GOV.
Dated at Rockville, Maryland, this 26th day
of March 2008.
For the Nuclear Regulatory Commission.
Gregory Trussell,
Acting NRC Clearance Officer, Office of
Information Services.
[FR Doc. E8–6626 Filed 3–31–08; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
[Docket No. 50–368]
Entergy Operations, Inc.; Arkansas
Nuclear One, Unit 2; Exemption
1.0 Background
Entergy Operations, Inc. (Entergy,
licensee), is the holder of Facility
Operating License No. NPF–6 which
authorizes operation of the Arkansas
Nuclear One, Unit 2 (ANO–2). The
license provides, among other things,
that the facility is subject to all rules,
regulations, and orders of the Nuclear
Regulatory Commission (NRC, the
Commission) now or hereafter in effect.
The facility consists of a pressurizedwater reactor (PWR) located in Pope
County, Arkansas.
2.0 Request/Action
Title 10 of the Code of Federal
Regulations (10 CFR) § 50.46,
‘‘Acceptance criteria for emergency core
cooling systems for light-water nuclear
power reactors,’’ requires, among other
items, that ‘‘[e]ach 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 [(LOCAs)] conforms to the
criteria set forth in paragraph (b) of this
section.’’ Appendix K to 10 CFR part 50,
‘‘ECCS Evaluation Models,’’ requires,
among other items, that the rate of
energy release, hydrogen generation,
and cladding oxidation from the metal/
water reaction shall be calculated using
the Baker-Just equation. The regulations
of 10 CFR 50.46 and 10 CFR part 50,
Appendix K, make no provision for use
of fuel rods clad in a material other than
zircaloy or ZIRLO. Since the chemical
composition of the Optimized ZIRLOTM
alloy differs from the specifications for
zircaloy or ZIRLO, a plant-specific
exemption is required to allow the use
of the Optimized ZIRLOTM alloy as a
cladding material at ANO–2. Therefore,
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by letter dated April 24, 2007, the
licensee requested the use of the
Optimized ZIRLOTM for fuel rod
cladding at ANO–2.
3.0 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 (1)
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; and
(2) when special circumstances are
present.
Authorized by Law
This exemption results in changes to
the operation of the plant by allowing
the use of the Optimized ZIRLOTM as
fuel rod cladding material in lieu of
zircaloy or ZIRLO. As stated above, 10
CFR 50.12 allows the NRC to grant
exemptions from the requirements of 10
CFR part 50. The NRC staff has
determined that granting of the
licensee’s proposed exemption will 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.
No Undue Risk to Public Health and
Safety
By letter dated June 10, 2005, the NRC
staff approved Westinghouse Topical
Report WCAP–12610–P–A and CENPD–
404–P–A, Addendum 1–A, ‘‘Optimized
ZIRLOTM’’ (Agencywide Documents
Access and Management System
(ADAMS) Accession No.
ML051670408). The NRC staff approved
the use of Optimized ZIRLOTM as a fuel
cladding material based on: (1)
Similarities with standard ZIRLOTM, (2)
demonstrated material performance, and
(3) a commitment to provide irradiated
data and validate fuel performance
models ahead of burnups achieved in
batch application. The NRC staff’s safety
evaluation for Optimized ZIRLOTM
includes 10 conditions and limitations
for its use. In addition, the NRC’s June
10, 2005, safety evaluation for
Optimized ZIRLOTM recommends that
the computer codes used to perform fuel
design safety analyses incorporate the
material properties of Optimized
ZIRLOTM.
The underlying purpose of 10 CFR
50.46 is to establish acceptance criteria
for ECCS performance. The applicability
of these ECCS acceptance criteria has
been demonstrated by Westinghouse.
Ring compression tests performed by
Westinghouse on Optimized ZIRLO TM
(documented in Appendix B of WCAP–
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Federal Register / Vol. 73, No. 63 / Tuesday, April 1, 2008 / Notices
12610–P–A and CENPD–404–P–A,
Addendum 1–A ‘‘Optimized ZIRLO TM,’’
July 2006, ADAMS Accession No.
ML062080576) demonstrate an
acceptable retention of post-quench
ductility up to 2200 degrees Fahrenheit
[°F] and 17 percent equivalent clad
reacted 10 CFR 50.46 limits.
Furthermore, oxidation measurements
provided by the licensee (by letter dated
November 6, 2007, ‘‘SER [Safety
Evaluation Report] Compliance with
WCAP–12610–P–A & CENPD–404–P–A
Addendum 1–A ‘Optimized ZIRLO TM’,’’
LTR–NRC–07–58, ADAMS Accession
No. ML073130562), illustrate that oxide
thickness (and associated hydrogen
pickup) for Optimized ZIRLO TM at any
given burnup would be less than both
Zircaloy-4 and ZIRLO TM. Hence,
Optimized ZIRLO TM would be expected
to maintain better post-quench ductility.
This finding is based on an ongoing
LOCA research program at Argonne
National Laboratory which has
identified a strong correlation between
cladding hydrogen content (due to inservice corrosion) and post-quench
ductility.
Utilizing currently approved LOCA
models and methods, Westinghouse
performed a plant-specific evaluation
and found that the Optimized ZIRLO TM
fuel rods will satisfy the 10 CFR 50.46
acceptance criteria. Therefore, the
exemption request continues to ensure
that the underlying purpose of the rule
is achieved.
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 BakerJust equation presumes the use of
zircaloy clad fuel, strict application of
the rule would not permit use of the
equation for Optimized ZIRLO TM
cladding for determining acceptable fuel
performance. Metal-water reaction tests
performed by Westinghouse on
Optimized ZIRLO TM (documented in
Appendix B of WCAP–12610–P–A and
CENPD–404–P–A, Addendum 1–A)
demonstrate conservative reaction rates
relative to the Baker-Just equation.
Thus, a prohibition on the use of
Optimized ZIRLO TM is not necessary for
the licensee to achieve the underlying
purpose of paragraph I.A.5 of Appendix
K in these circumstances.
Based on the above, no new accident
precursors are created by using
Optimized ZIRLO TM, thus, the
probability of postulated accidents is
not increased. Also, based on the above,
the consequences of postulated
accidents are not increased. In addition,
the licensee will use NRC-approved
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methods for the reload design process
for ANO–2 reloads with Optimized
ZIRLO TM. Therefore, there is no undue
risk to public health and safety due to
using Optimized ZIRLO TM.
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 would
not serve the underlying purpose of the
rule or is not necessary to achieve the
underlying purpose of the rule. In this
circumstance, neither 10 CFR 50.46 nor
10 CFR part 50, Appendix K, explicitly
allows the use of Optimized ZIRLO TM
as a fuel rod cladding material.
The underlying purpose of 10 CFR
50.46 is to ensure that facilities have
adequate acceptance criteria for the
ECCS. Based upon results of metalwater reaction tests and ringcompression tests which ensure the
applicability of ECCS models and
acceptance criteria and the use of
approved LOCA models to ensure
compliance to 10 CFR 50.46 acceptance
criteria, the staff finds it acceptable to
grant an exemption from the 10 CFR
50.46 and Appendix K to 10 CFR part
50 to allow the use of Optimized
ZIRLO TM in future reloads at ANO–2.
On June 10, 2005, the NRC staff
approved WCAP–12610–P–A and
CENPD–404–P–A, Addendum 1–A, in
which Westinghouse demonstrated that
the effectiveness of the ECCS will not be
affected by a change from zircaloy to
Optimized ZIRLO TM. The analysis
described in the WCAP–12610–P–A and
CENPD–404–P–A also demonstrated
that the ECCS acceptance criteria
applied to reactors fueled with zircaloy
fuel rod cladding are also applicable to
reactors fueled with Optimized
ZIRLO TM WCAP–12610–P–A and
CENPD–404–P–A fuel rod cladding.
The underlying purpose of 10 CFR
part 50, Appendix K, paragraph 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 to
10 CFR part 50 requires that the BakerJust equation be used in the ECCS
evaluation model to determine the rate
of energy release, cladding oxidation,
and hydrogen generation. In WCAP–
12610–P–A and CENPD–404–P–A,
Addendum 1–A , Westinghouse
demonstrated that the Baker-Just model
is conservative in all post-LOCA
scenarios with respect to the use of the
Optimized ZIRLOTM as a fuel rod
cladding material, and that the amount
of hydrogen generated in an Optimized
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17385
ZIRLOTM core during a LOCA will
remain within the ANO–2 design basis.
Optimized ZIRLOTM is a niobium-tiniron (Nb-Sn-Fe) zirconium (Zr) based
alloy with a microstructure comprised
of a body-centered cubic ZrNb phase
and a close-packed hexagonal ZrNbFe
phase homogeneously distributed
throughout the zirconium matrix.
Optimized ZIRLOTM fuel cladding is
different from standard ZIRLOTM in two
respects: (1) The Sn content is lower,
and (2) the microstructure is different.
This difference in Sn content and
microstructure can lead to differences in
some material properties. Most of the
material properties of standard ZIRLOTM
and Optimized ZIRLOTM are the same
within the uncertainty of the data and,
therefore, use of standard ZIRLOTM
properties for safety analyses is
acceptable. The NRC staff has reviewed
the licensee’s request to use Optimized
ZIRLOTM for PWR fuel mechanical
designs as described in WCAP–12610–
P–A and CENPD–404–P–A, Addendum
1–A. In the June 10, 2005, safety
evaluation for WCAP–12610–P–A and
CENPD–404–P–A, Addendum 1–A, the
NRC staff concluded that, to the extent
specified in the NRC staff’s evaluation,
the Optimized ZIRLOTM properties and
mechanical design methodology are
acceptable for referencing in fuel reload
licensing applications. Therefore, since
the underlying purposes of 10 CFR
50.46 and 10 CFR part 50, Appendix K,
paragraph I.A.5 are achieved through
the use of the Optimized ZIRLOTM as a
fuel rod cladding material, the special
circumstances required by 10 CFR
50.12(a)(2)(ii) for the granting of an
exemption from 10 CFR 50.46 and
Appendix K to 10 CFR part 50, exist.
Summary
The NRC staff has reviewed the
licensee’s request to use the Optimized
ZIRLOTM for fuel rod cladding in lieu of
zircaloy or ZIRLO. Based on the NRC
staff’s evaluation, as set forth above, the
NRC staff concludes that the exemption
is authorized by law, will not present an
undue risk to public health and safety,
and is consistent with the common
defense and security. In addition, the
NRC staff concludes that the underlying
purposes of 10 CFR 50.46 and Appendix
K to 10 CFR part 50, are achieved
through the use of the Optimized
ZIRLOTM alloy. Therefore, pursuant to
10 CFR 50.12(a), the NRC staff
concludes that the use of the Optimized
ZIRLOTM alloy for fuel rod cladding is
acceptable and the exemption from 10
CFR 50.46 and Appendix K to 10 CFR
part 50, is justified. Although the use of
Optimized ZIRLOTM is allowed, the
other requirements of 10 CFR 50.46 and
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Federal Register / Vol. 73, No. 63 / Tuesday, April 1, 2008 / Notices
Appendix K to 10 CFR part 50 apply to
the use of Optimized ZIRLOTM. The
conditions and limitations on the use of
Optimized ZIRLOTM will be discussed
in the staff’s action on the license
amendment request submitted by the
applicant dated April 24, 2007.
data and information provided in
several technical conferences.
The Commission’s report can be
accessed via https://www.prc.gov.
Related documents can also be found on
the Commission’s Web site under the
‘‘Contents’’ tab, Docket No. ACR2007.
4.0
Dated: March 27, 2008.
Steven W. Williams,
Secretary.
[FR Doc. E8–6701 Filed 3–31–08; 8:45 am]
Conclusion
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, and is
consistent with the common defense
and security. Also, special
circumstances are present. Therefore,
the Commission hereby grants Entergy
an exemption from the requirements of
10 CFR 50.46 and Appendix K to 10
CFR Part 50, for ANO–2.
Pursuant to 10 CFR 51.32, the
Commission has determined that the
granting of this exemption will not have
a significant impact on the quality of the
human environment as published in the
Federal Register on March 10, 2008 (73
FR 12779). This exemption is effective
upon issuance.
Dated at Rockville, Maryland, this 19 day
of March 2008.
For the Nuclear Regulatory Commission.
Catherine Haney,
Director, Division of Operating Reactor
Licensing, Office of Nuclear Reactor
Regulation.
[FR Doc. E8–6630 Filed 3–31–08; 8:45 am]
BILLING CODE 7590–01–P
POSTAL REGULATORY COMMISSION
[Docket No. ACR2007]
Postal Service Oversight
Postal Regulatory Commission.
Availability of report.
AGENCY:
ACTION:
FOR FURTHER INFORMATION CONTACT:
Stephen L. Sharman, General Counsel,
at 202–789–6820 or
stephen.sharfman@prc.gov.
The Postal
Regulatory Commission (Commission)
has issued its first Annual Compliance
Determination addressing the United
States Postal Service’s recent financial
and service performance. The
Commission’s determination, dated
March 27, 2008, responds to a directive
in the Postal Accountability and
Enhancement Act (PAEA) of 2006. See
39 U.S.C. 3653. It was prepared after
review of the Postal Service’s 2007
Annual Compliance Report and
supplemental material, evaluation of
public comments, and assessment of
mstockstill on PROD1PC66 with NOTICES
SUPPLEMENTARY INFORMATION:
VerDate Aug<31>2005
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BILLING CODE 7710–FW–P
SECURITIES AND EXCHANGE
COMMISSION
Sunshine Act Meeting
FEDERAL REGISTER CITATION OF PREVIOUS
ANNOUNCEMENT: [to be published].
Closed Meeting.
100 F Street, NE., Washington,
STATUS:
PLACE:
DC.
DATE AND TIME OF PREVIOUSLY ANNOUNCED
MEETING: March 31, 2008 at 10 a.m.
CHANGE IN THE MEETINGS:
Date and Time
Change.
The Closed Meeting scheduled for
Monday, March 31, 2008 at 10 a.m., has
been changed to Wednesday, April 2,
2008 at 10 a.m.
At times, changes in Commission
priorities require alterations in the
scheduling of meeting items. For further
information and to ascertain what, if
any, matters have been added, deleted
or postponed, please contact:
The Office of the Secretary at (202)
551–5400.
Dated: March 27, 2008.
Nancy M. Morris,
Secretary.
[FR Doc. E8–6718 Filed 3–31–08; 8:45 am]
BILLING CODE 8011–01–P
SECURITIES AND EXCHANGE
COMMISSION
[Release No. 34–57557; File No. SR–ISE–
2008–25]
Self-Regulatory Organizations;
International Securities Exchange,
LLC; Notice of Filing of Proposed Rule
Change, and Amendment No. 1
Thereto, Relating to the Rescission of
the ‘‘No MPM’’ Order Type
March 26, 2008.
Pursuant to section 19(b)(1) of the
Securities Exchange Act of 1934
(‘‘Act’’)1 and Rule 19b–4 thereunder,2
notice is hereby given that on March 5,
115
217
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U.S.C. 78s(b)(1).
CFR 240.19b–4.
Frm 00093
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Sfmt 4703
2008, the International Securities
Exchange, LLC (‘‘Exchange’’ or ‘‘ISE’’)
filed with the Securities and Exchange
Commission (‘‘Commission’’) the
proposed rule change as described in
Items I, II, and III below, which Items
have been substantially prepared by the
Exchange. On March 17, 2008, the
Exchange filed Amendment No. 1 to the
proposed rule change. The Commission
is publishing this notice to solicit
comments on the proposed rule change,
as amended, from interested persons.
I. Self-Regulatory Organization’s
Statement of the Terms of Substance of
the Proposed Rule Change
The ISE proposes to amend its rules
to rescind the ‘‘No MPM’’ order type.
The text of the proposed rule change is
below. Proposed new language is
italicized; proposed deletions are
enclosed in brackets.
*
*
*
*
*
Rule 2104. Types of Orders
(a)–(g) No change.
[(h) No MPM. Market or limit orders
that should not be executed against
orders residing in the Midpoint Match.
(See Rule 2129)]
[(i)](h) No further change.
[(j)](i) No further change.
[(k)](j) No further change.
[(l)](k) No further change.
[(m)](l) No further change.
[(n)](m) No further change.
[(o)](n) No further change.
*
*
*
*
*
2106. Opening Process
(a) No change.
(1) All order types other than Stop/
Stop Limit, [No MPM,] Post Only, FOK
and IOC may participate in the opening
transaction. Reserve orders may
participate to the full extent of their
size. Discretionary orders may
participate at their most aggressive
prices. Pegged orders will have limit
prices based upon the NBBO that is
required for the opening transaction to
occur.
(2)–(3) No change.
(b)–(f) No change.
*
*
*
*
*
2107. Priority and Execution of Orders
(a) No change.
(b) Order Execution. All orders are
handled automatically by the ISE Stock
Exchange. All orders are available for
price improvement at the midpoint of
the NBBO if contra-side interest exists
in Midpoint Match[, unless marked ‘‘No
MPM’’]. Except as specified below in
paragraph (c), orders will not be
executed at prices that are inferior to
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]]>Agencies
[Federal Register Volume 73, Number 63 (Tuesday, April 1, 2008)]
[Notices]
[Pages 17384-17386]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-6630]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket No. 50-368]
Entergy Operations, Inc.; Arkansas Nuclear One, Unit 2; Exemption
1.0 Background
Entergy Operations, Inc. (Entergy, licensee), is the holder of
Facility Operating License No. NPF-6 which authorizes operation of the
Arkansas Nuclear One, Unit 2 (ANO-2). The license provides, among other
things, that the facility is subject to all rules, regulations, and
orders of the Nuclear Regulatory Commission (NRC, the Commission) now
or hereafter in effect.
The facility consists of a pressurized-water reactor (PWR) located
in Pope County, Arkansas.
2.0 Request/Action
Title 10 of the Code of Federal Regulations (10 CFR) Sec. 50.46,
``Acceptance criteria for emergency core cooling systems for light-
water nuclear power reactors,'' requires, among other items, that
``[e]ach 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 [(LOCAs)] conforms to
the criteria set forth in paragraph (b) of this section.'' Appendix K
to 10 CFR part 50, ``ECCS Evaluation Models,'' requires, among other
items, that the rate of energy release, hydrogen generation, and
cladding oxidation from the metal/water reaction shall be calculated
using the Baker-Just equation. The regulations of 10 CFR 50.46 and 10
CFR part 50, Appendix K, make no provision for use of fuel rods clad in
a material other than zircaloy or ZIRLO. Since the chemical composition
of the Optimized ZIRLOTM alloy differs from the
specifications for zircaloy or ZIRLO, a plant-specific exemption is
required to allow the use of the Optimized ZIRLOTM alloy as
a cladding material at ANO-2. Therefore, by letter dated April 24,
2007, the licensee requested the use of the Optimized
ZIRLOTM for fuel rod cladding at ANO-2.
3.0 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 (1) 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; and
(2) when special circumstances are present.
Authorized by Law
This exemption results in changes to the operation of the plant by
allowing the use of the Optimized ZIRLOTM as fuel rod
cladding material in lieu of zircaloy or ZIRLO. As stated above, 10 CFR
50.12 allows the NRC to grant exemptions from the requirements of 10
CFR part 50. The NRC staff has determined that granting of the
licensee's proposed exemption will 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.
No Undue Risk to Public Health and Safety
By letter dated June 10, 2005, the NRC staff approved Westinghouse
Topical Report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A,
``Optimized ZIRLOTM'' (Agencywide Documents Access and
Management System (ADAMS) Accession No. ML051670408). The NRC staff
approved the use of Optimized ZIRLOTM as a fuel cladding
material based on: (1) Similarities with standard ZIRLOTM,
(2) demonstrated material performance, and (3) a commitment to provide
irradiated data and validate fuel performance models ahead of burnups
achieved in batch application. The NRC staff's safety evaluation for
Optimized ZIRLOTM includes 10 conditions and limitations for
its use. In addition, the NRC's June 10, 2005, safety evaluation for
Optimized ZIRLOTM recommends that the computer codes used to
perform fuel design safety analyses incorporate the material properties
of Optimized ZIRLOTM.
The underlying purpose of 10 CFR 50.46 is to establish acceptance
criteria for ECCS performance. The applicability of these ECCS
acceptance criteria has been demonstrated by Westinghouse. Ring
compression tests performed by Westinghouse on Optimized ZIRLO
TM (documented in Appendix B of WCAP-
[[Page 17385]]
12610-P-A and CENPD-404-P-A, Addendum 1-A ``Optimized ZIRLO
TM,'' July 2006, ADAMS Accession No. ML062080576)
demonstrate an acceptable retention of post-quench ductility up to 2200
degrees Fahrenheit [[deg]F] and 17 percent equivalent clad reacted 10
CFR 50.46 limits. Furthermore, oxidation measurements provided by the
licensee (by letter dated November 6, 2007, ``SER [Safety Evaluation
Report] Compliance with WCAP-12610-P-A & CENPD-404-P-A Addendum 1-A
`Optimized ZIRLO TM','' LTR-NRC-07-58, ADAMS Accession No.
ML073130562), illustrate that oxide thickness (and associated hydrogen
pickup) for Optimized ZIRLO TM at any given burnup would be
less than both Zircaloy-4 and ZIRLO TM. Hence, Optimized
ZIRLO TM would be expected to maintain better post-quench
ductility. This finding is based on an ongoing LOCA research program at
Argonne National Laboratory which has identified a strong correlation
between cladding hydrogen content (due to in-service corrosion) and
post-quench ductility.
Utilizing currently approved LOCA models and methods, Westinghouse
performed a plant-specific evaluation and found that the Optimized
ZIRLO TM fuel rods will satisfy the 10 CFR 50.46 acceptance
criteria. Therefore, the exemption request continues to ensure that the
underlying purpose of the rule is achieved.
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 Optimized ZIRLO TM cladding for determining
acceptable fuel performance. Metal-water reaction tests performed by
Westinghouse on Optimized ZIRLO TM (documented in Appendix B
of WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A) demonstrate
conservative reaction rates relative to the Baker-Just equation. Thus,
a prohibition on the use of Optimized ZIRLO TM is not
necessary for the licensee to achieve the underlying purpose of
paragraph I.A.5 of Appendix K in these circumstances.
Based on the above, no new accident precursors are created by using
Optimized ZIRLO TM, thus, the probability of postulated
accidents is not increased. Also, based on the above, the consequences
of postulated accidents are not increased. In addition, the licensee
will use NRC-approved methods for the reload design process for ANO-2
reloads with Optimized ZIRLO TM. Therefore, there is no
undue risk to public health and safety due to using Optimized ZIRLO
TM.
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 would not serve the underlying purpose of the rule or is
not necessary to achieve the underlying purpose of the rule. In this
circumstance, neither 10 CFR 50.46 nor 10 CFR part 50, Appendix K,
explicitly allows the use of Optimized ZIRLO TM as a fuel
rod cladding material.
The underlying purpose of 10 CFR 50.46 is to ensure that facilities
have adequate acceptance criteria for the ECCS. Based upon results of
metal-water reaction tests and ring-compression tests which ensure the
applicability of ECCS models and acceptance criteria and the use of
approved LOCA models to ensure compliance to 10 CFR 50.46 acceptance
criteria, the staff finds it acceptable to grant an exemption from the
10 CFR 50.46 and Appendix K to 10 CFR part 50 to allow the use of
Optimized ZIRLO TM in future reloads at ANO-2.
On June 10, 2005, the NRC staff approved WCAP-12610-P-A and CENPD-
404-P-A, Addendum 1-A, in which Westinghouse demonstrated that the
effectiveness of the ECCS will not be affected by a change from
zircaloy to Optimized ZIRLO TM. The analysis described in
the WCAP-12610-P-A and CENPD-404-P-A also demonstrated that the ECCS
acceptance criteria applied to reactors fueled with zircaloy fuel rod
cladding are also applicable to reactors fueled with Optimized ZIRLO
TM WCAP-12610-P-A and CENPD-404-P-A fuel rod cladding.
The underlying purpose of 10 CFR part 50, Appendix K, paragraph
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 to 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. In WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A ,
Westinghouse demonstrated that the Baker-Just model is conservative in
all post-LOCA scenarios with respect to the use of the Optimized
ZIRLOTM as a fuel rod cladding material, and that the amount
of hydrogen generated in an Optimized ZIRLOTM core during a
LOCA will remain within the ANO-2 design basis.
Optimized ZIRLOTM is a niobium-tin-iron (Nb-Sn-Fe)
zirconium (Zr) based alloy with a microstructure comprised of a body-
centered cubic ZrNb phase and a close-packed hexagonal ZrNbFe phase
homogeneously distributed throughout the zirconium matrix. Optimized
ZIRLOTM fuel cladding is different from standard
ZIRLOTM in two respects: (1) The Sn content is lower, and
(2) the microstructure is different. This difference in Sn content and
microstructure can lead to differences in some material properties.
Most of the material properties of standard ZIRLOTM and
Optimized ZIRLOTM are the same within the uncertainty of the
data and, therefore, use of standard ZIRLOTM properties for
safety analyses is acceptable. The NRC staff has reviewed the
licensee's request to use Optimized ZIRLOTM for PWR fuel
mechanical designs as described in WCAP-12610-P-A and CENPD-404-P-A,
Addendum 1-A. In the June 10, 2005, safety evaluation for WCAP-12610-P-
A and CENPD-404-P-A, Addendum 1-A, the NRC staff concluded that, to the
extent specified in the NRC staff's evaluation, the Optimized
ZIRLOTM properties and mechanical design methodology are
acceptable for referencing in fuel reload licensing applications.
Therefore, since the underlying purposes of 10 CFR 50.46 and 10 CFR
part 50, Appendix K, paragraph I.A.5 are achieved through the use of
the Optimized ZIRLOTM as a fuel rod cladding material, the
special circumstances required by 10 CFR 50.12(a)(2)(ii) for the
granting of an exemption from 10 CFR 50.46 and Appendix K to 10 CFR
part 50, exist.
Summary
The NRC staff has reviewed the licensee's request to use the
Optimized ZIRLOTM for fuel rod cladding in lieu of zircaloy
or ZIRLO. Based on the NRC staff's evaluation, as set forth above, the
NRC staff concludes that the exemption is authorized by law, will not
present an undue risk to public health and safety, and is consistent
with the common defense and security. In addition, the NRC staff
concludes that the underlying purposes of 10 CFR 50.46 and Appendix K
to 10 CFR part 50, are achieved through the use of the Optimized
ZIRLOTM alloy. Therefore, pursuant to 10 CFR 50.12(a), the
NRC staff concludes that the use of the Optimized ZIRLOTM
alloy for fuel rod cladding is acceptable and the exemption from 10 CFR
50.46 and Appendix K to 10 CFR part 50, is justified. Although the use
of Optimized ZIRLOTM is allowed, the other requirements of
10 CFR 50.46 and
[[Page 17386]]
Appendix K to 10 CFR part 50 apply to the use of Optimized
ZIRLOTM. The conditions and limitations on the use of
Optimized ZIRLOTM will be discussed in the staff's action on
the license amendment request submitted by the applicant dated April
24, 2007.
4.0 Conclusion
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, and is consistent with the common
defense and security. Also, special circumstances are present.
Therefore, the Commission hereby grants Entergy an exemption from the
requirements of 10 CFR 50.46 and Appendix K to 10 CFR Part 50, for ANO-
2.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant impact on the
quality of the human environment as published in the Federal Register
on March 10, 2008 (73 FR 12779). This exemption is effective upon
issuance.
Dated at Rockville, Maryland, this 19 day of March 2008.
For the Nuclear Regulatory Commission.
Catherine Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. E8-6630 Filed 3-31-08; 8:45 am]
BILLING CODE 7590-01-P
