Florida Power and Light Company; Turkey Point, Units 3 and 4; Exemption, 13142-13144 [2010-5927]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 75, Number 52 (Thursday, March 18, 2010)]
[Notices]
[Pages 13142-13144]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-5927]



[[Page 13142]]

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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-250 and 50-251; NRC-2010-0025]


Florida Power and Light Company; Turkey Point, Units 3 and 4; 
Exemption

1.0 Background

    Florida Power and Light Company (FPL, the licensee), is the holder 
of Facility Operating License Nos. DPR-31 and DPR-41, which authorize 
operation of the Turkey Point, Unit Nos. 3 and 4 (Turkey Point 3 and 
4). 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, the Commission) now or hereafter in effect. 
The facility consists of two pressurized-water reactors located in 
Florida City, Florida.

2.0 Request

    Title 10 of the Code of Federal Regulations (10 CFR), part 50, 
Appendix G requires that fracture toughness requirements for ferritic 
materials of pressure-retaining components of the reactor coolant 
pressure boundary of light water nuclear power reactors need to provide 
adequate margins of safety during any condition of normal operation, 
including anticipated operational occurrences and system hydrostatic 
tests, to which the pressure boundary may be subjected over its service 
lifetime; and 10 CFR 50.61 provides fracture toughness requirements for 
protection against pressurized thermal shock (PTS) events. By letter 
dated March 18, 2009, (Agencywide Documents Access and Management 
System (ADAMS) Accession No. ML090920408), FPL proposed exemptions from 
the requirements of 10 CFR Part 50, Appendix G and 10 CFR 50.61, to 
revise certain Turkey Point 3 and 4, reactor pressure vessel (RPV) 
initial (unirradiated) properties using Framatome Advanced Nuclear 
Power Topical Report (TR) BAW-2308, Revisions 1A and 2A, ``Initial 
RTNDT of Linde 80 Weld Materials.'' This exemption addresses 
only those parts of the regulations (i.e., 10 CFR 50.61 and 10 CFR Part 
50, Appendix G) which discuss the definition or use of unirradiated 
nil-ductility reference temperature, RTNDT(U), and its 
associated uncertainty, [sigma][Delta]. All other 
requirements of 10 CFR 50.61 and 10 CFR part 50, Appendix G are 
unchanged by this exemption.
    The licensee requested an exemption from Appendix G to 10 CFR part 
50 to replace the required use of the existing Charpy V-notch and drop 
weight-based methodology and allow the use of an alternate methodology 
to incorporate the use of fracture toughness test data for evaluating 
the integrity of the Turkey Point 3 and 4 RPV circumferential beltline 
welds based on the use of the 1997 and 2002 Editions of American 
Society for Testing and Materials (ASTM) Standard Test Method E 1921, 
``Standard Test Method for Determination of Reference Temperature, 
T0, for Ferritic Steels in the Transition Range,'' and 
American Society for Mechanical Engineering (ASME), Boiler and Pressure 
Vessel Code (Code), Code Case N-629, ``Use of Fracture Toughness Test 
Data to establish Reference Temperature for Pressure Retaining 
Materials of Section III, Division 1, Class 1.'' The exemption is 
required since Appendix G to 10 CFR part 50, through reference to 
Appendix G to Section XI of the ASME Code pursuant to 10 CFR 50.55(a), 
requires the use of a methodology based on Charpy V-notch and drop-
weight data. The licensee also requested an exemption from 10 CFR 50.61 
to use an alternate methodology to allow the use of fracture toughness 
test data for evaluating the integrity of the Turkey Point 3 and 4 RPV 
circumferential beltline welds based on the use of the 1997 and 2002 
Editions of ASTM E 1921 and ASME Code Case N-629. The exemption is 
required since the methodology for evaluating RPV material fracture 
toughness in 10 CFR 50.61 requires the use of the Charpy V-notch and 
drop-weight data for establishing the PTS reference temperature 
(RTPTS).
    On February 3, 2010, a new rule, 10 CFR 50.61a, ``Alternate 
Fracture Toughness Requirements for Protection Against PTS Events,'' 
became effective. The NRC staff reviewed this new rule against Turkey 
Point's exemption request and determined that there is no effect on the 
exemption request. The new rule does not modify the requirements from 
which the licensee has sought an exemption, and the alternative 
provided by the new rule does not address the scope of issues 
associated with both 10 CFR 50.61 and 10 CFR part 50, Appendix G that 
the requested exemption does.

3.0 Discussion

    Pursuant to 10 CFR 50.12(a), 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. The licensee requested an 
exemption from the use of the Charpy V-notch and drop-weight-based 
methodology required by 10 CFR part 50, Appendix G and 10 CFR 50.61. 
This exemption only modifies the methodology to be used by the licensee 
for demonstrating compliance with the requirements of 10 CFR part 50, 
Appendix G and 10 CFR 50.61, and does not exempt the licensee from 
meeting any other requirement of 10 CFR part 50, Appendix G and 10 CFR 
50.61.

Authorized by Law

    These exemptions would allow the licensee to use an alternate 
methodology to make use of fracture toughness test data for evaluating 
the integrity of the Turkey Point 3 and 4 RPV circumferential beltline 
welds, and would not result in changes to operation of the plant. 
Section 50.60(b) of 10 CFR Part 50 allows the use of alternatives to 10 
CFR part 50, Appendix G, or portions thereof, when an exemption is 
granted by the Commission under 10 CFR 50.12. In addition, Section 
50.60(b) of 10 CFR part 50 permits different NRC-approved methods for 
use in determining the initial material properties. As stated above, 10 
CFR 50.12(a) allows the NRC to grant exemptions from the requirements 
of 10 CFR Part 50, Appendix G and 10 CFR 50.61. The NRC staff has 
determined that granting of the licensee's proposed exemptions will not 
result in a violation of the Atomic Energy Act of 1954, as amended, or 
the Commission's regulations. Therefore, the exemptions are authorized 
by law.

No Undue Risk to Public Health and Safety

    The underlying purpose of Appendix G to 10 CFR part 50 is to set 
forth fracture toughness requirements for ferritic materials of 
pressure-retaining components of the reactor coolant pressure boundary 
of light water nuclear power reactors to provide adequate margins of 
safety during any condition of normal operation, including anticipated 
operational occurrences and system hydrostatic tests, to which the 
pressure boundary may be subjected over its service lifetime. The 
methodology underlying the requirements of Appendix G to 10 CFR part 50 
is based on the use of Charpy V-notch and drop-weight data. The 
licensee proposes to replace the use of the existing Charpy V-notch and 
drop-weight-based methodology by a fracture toughness-based methodology 
to

[[Page 13143]]

demonstrate compliance with Appendix G to 10 CFR part 50.
    The NRC staff has concluded that the exemptions are justified based 
on the licensee utilizing the fracture toughness methodology specified 
in BAW-2308, Revisions 1A and 2A, within the conditions and limitations 
delineated in the NRC staff's safety evaluations (SEs), dated August 4, 
2005 (ADAMS Accession Number ML052070408) and March 24, 2008 
(ML080770349). The use of the methodology specified in the NRC staff's 
SEs will ensure that pressure and temperature limits developed for the 
Turkey Point 3 and 4 RPVs will continue to be based on an adequately 
conservative estimate of RPV material properties and ensure that the 
pressure-retaining components of the reactor coolant pressure boundary 
retain adequate margins of safety during any condition of normal 
operation, including anticipated operational occurrences. This 
exemption only modifies the methodology to be used by the licensee for 
demonstrating compliance with the requirements of Appendix G to 10 CFR 
part 50, and does not exempt the licensee from meeting any other 
requirement of Appendix G to 10 CFR part 50.
    The underlying purpose of 10 CFR 50.61 is to establish requirements 
that ensure a licensee's RPV will be protected from failure during a 
PTS event by evaluating the fracture toughness of RPV materials. The 
licensee seeks an exemption from 10 CFR 50.61 to use a methodology for 
the determination of adjusted/indexing reference temperatures. The 
licensee proposes to use ASME Code Case N-629 and the methodology 
outlined in its submittal, which are based on the use of fracture 
toughness data, as an alternative to the Charpy V-notch and drop-
weight-based methodology required by 10 CFR 50.61 for establishing the 
initial, unirradiated properties when calculating RTPTS 
values. The NRC staff has concluded that the exemption is justified 
based on the licensee utilizing the methodology specified in the NRC 
staff's SEs regarding TR BAW-2308, Revisions 1A and 2A, dated August 4, 
2005, and March 24, 2008. This TR established an alternative method for 
determining initial (unirradiated) material reference temperatures for 
RPV welds manufactured using Linde 80 weld flux (i.e., ``Linde 80 
welds'') and established weld wire heat-specific and Linde 80 weld 
generic values of this reference temperature. These weld wire heat-
specific and Linde 80 weld generic values may be used in lieu of the 
nil-ductility reference temperature (RTNDT) parameter, the 
determination of which is specified by paragraph NB-2331 of Section III 
of the ASME Code. Regulations associated with the determination of RPV 
material properties involving protection of the RPV from brittle 
failure or ductile rupture include Appendix G to 10 CFR Part 50 and 10 
CFR 50.61, the PTS rule. These regulations require that the initial 
(unirradiated) material reference temperature, IRTNDT, be 
determined in accordance with the provisions of the ASME Code, and 
provide the process for determination of RTPTS, the 
reference temperature RTNDT, evaluated for the end of 
license fluence.
    In TR BAW-2308, Revision 1, the Babcock and Wilcox Owners Group 
(B&WOG) proposed to perform fracture toughness testing based on the 
application of the ``Master Curve'' evaluation procedure, which permits 
data obtained from sample sets tested at different temperatures to be 
combined, as the basis for redefining the initial (unirradiated) 
material properties of Linde 80 welds. NRC staff evaluated this 
methodology for determining Linde 80 weld initial (unirradiated) 
material properties and uncertainty in those properties, as well as the 
overall method for combining unirradiated material property 
measurements based on To values (i.e., IRTTo), 
property shifts from models in Regulatory Guide (RG) 1.99, Revision 2, 
which are based on Charpy V-notch testing and a defined margin term to 
account for uncertainties in the NRC staff SE. Table 3 in the SE 
contains the NRC staff-accepted IRTTo and initial margin 
(denoted as [sigma]i) for specific Linde 80 weld wire heat 
numbers. In accordance with the conditions and limitations outlined in 
the NRC staff SE on TR BAW-2308, Revision 1, for utilizing the values 
in Table 3: the licensee has utilized the appropriate NRC staff-
accepted IRTTo and [sigma]i values for Linde 80 
weld wire heat numbers; applied a chemistry factor of 167 [deg]F (the 
weld wire heat-specific chemical composition, via the methodology of RG 
1.99, Revision 2, did not indicate that a higher chemistry factor 
should apply); applied a value of 28 [deg]F for 
[sigma][Delta] in the margin term; and submitted values for 
[Delta]RTNDT and the margin term for each Linde 80 weld in 
the RPV through the end of the current operating license. Additionally, 
the NRC's SE for TR BAW-2308, Revision 2 concludes that the revised 
RTPTS values for Linde 80 weld materials are acceptable for 
referencing in plant specific licensing applications as delineated in 
TR BAW-2308, Revision 2 and to the extent specified under Section 4.0, 
Limitations and Conditions, of the SE, which states: ``Future plant-
specific applications for RPVs containing weld heat 72105, and weld 
heat 299L44, of Linde 80 welds must use the revised IRTTo 
and [sigma]i, values in TR BAW-2308, Revision 2.'' 
Therefore, all conditions and limitations outlined in the NRC staff SEs 
on TR BAW-2308, Revisions 1A and 2A, have been met for Turkey Point 3 
and 4.
    The use of the methodology in TR BAW-2308, Revisions 1A and 2A will 
ensure the PTS evaluation developed for the Turkey Point 3 and 4 RPVs 
will continue to be based on an adequately conservative estimate of RPV 
material properties and ensure the RPVs will be protected from failure 
during a PTS event.
    Based on the above, no new accident precursors are created by 
allowing an exemption to use an alternate methodology to comply with 
the requirements of 10 CFR 50.61 in determining adjusted/indexing 
reference temperatures, thus, the probability of postulated accidents 
is not increased. Also, based on the above, the consequences of 
postulated accidents are not increased. Therefore, there is no undue 
risk to public health and safety.

Consistent With Common Defense and Security

    The proposed exemption would allow the licensee to use an alternate 
methodology to allow the use of fracture toughness test data for 
evaluating the integrity of the Turkey Point 3 and 4 RPV 
circumferential beltline welds. This change to Turkey Point 3 and 4 has 
no relation to security issues. Therefore, the common defense and 
security is not impacted by these exemptions.

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 Part 50, Appendix G and 10 CFR 
50.61 is to protect the integrity of the reactor coolant pressure 
boundary by ensuring that each reactor vessel material has adequate 
fracture toughness. Therefore, since the underlying purpose of 10 CFR 
part 50, Appendix G and 10 CFR 50.61 is achieved by an alternative 
methodology for evaluating RPV material fracture toughness, the special 
circumstances required by 10 CFR 50(a)(2)(ii) for the granting of an 
exemption from portions of the requirements of 10 CFR part 50, Appendix 
G and 10 CFR 50.61 exist.

[[Page 13144]]

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemptions are authorized by law, will not endanger life 
or property or common defense and security, and is, otherwise, in the 
public interest. Therefore, the Commission hereby grants the Florida 
Power and Light Company exemptions from portions of the requirements of 
Appendix G to 10 CFR part 50 and 10 CFR 50.61, to allow an alternative 
methodology that is based on using of fracture toughness test data to 
determine initial, unirradiated properties for evaluating the integrity 
of the Turkey Point RPV circumferential beltline welds. This exemption 
addresses only those parts of the regulations (i.e., 10 CFR 50.61 and 
10 CFR part 50, Appendix G) which discuss the definition or use of 
unirradiated nil-ductility reference temperature, RTNDT(U), 
and its associated uncertainty, [sigma][Delta]. All other 
requirements of 10 CFR 50.61 and 10 CFR part 50, Appendix G are 
unchanged by this exemption.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will not have a significant effect on the 
quality of the human environment (75 FR 4426)
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 11th day of March 2010.

    For the Nuclear Regulatory Commission.
Joseph G. Giitter,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 2010-5927 Filed 3-17-10; 8:45 am]
BILLING CODE 7590-01-P