80 FR 46066 - NextEra Energy Seabrook, LLC, Seabrook Station, Unit 1

NUCLEAR REGULATORY COMMISSION

Federal Register Volume 80, Issue 148 (August 3, 2015)

Page Range		46066-46069
FR Document		2015-19003
The U.S. Nuclear Regulatory Commission (NRC) is issuing an exemption in response to a July 24, 2014, request from NextEra Energy Seabrook, LLC (NextEra or the licensee), from specific requirements in NRC's regulations, as they pertain to the establishment of minimum temperature requirements, for all modes of operation, based on the material properties of the material of the reactor pressure vessel (RPV) closure flange region that is highly stressed by the bolt preload.
Federal Register, Volume 80 Issue 148 (Monday, August 3, 2015)
[Federal Register Volume 80, Number 148 (Monday, August 3, 2015)]
[Notices]
[Pages 46066-46069]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-19003]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-443; NRC-2015-0184]


NextEra Energy Seabrook, LLC, Seabrook Station, Unit 1

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 July 24, 2014, request from NextEra Energy 
Seabrook, LLC (NextEra or the licensee), from specific requirements in 
NRC's regulations, as they pertain to the establishment of minimum 
temperature requirements, for all modes of operation, based on the 
material properties of the material of the reactor pressure vessel 
(RPV) closure flange region that is highly stressed by the bolt 
preload.

ADDRESSES: Please refer to Docket ID NRC-2015-0184 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-2015-0184. 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 (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: John G. Lamb, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001; telephone: 301-415-3100, email: [email protected].

SUPPLEMENTARY INFORMATION: 

I. Background

    NextEra is the holder of Facility Operating License No. NPF-86, 
which authorizes operation of the Seabrook Station, Unit No. 1 
(Seabrook).
    The Seabrook facility consists of a pressurized-water reactor 
located in Rockingham County, New Hampshire.

II. Request/Action

    By letter dated July 24, 2014 (ADAMS Accession No. ML14216A404), as 
supplemented by letters dated March 9, April 24, and June 24, 2015 
(ADAMS Accession Nos. ML15072A023, ML15125A140, and ML15181A262, 
respectively), the licensee requested an exemption from section 50.60 
of Title 10 of the Code of Federal Regulations (10 CFR), ``Acceptance 
criteria for fracture prevention measures for lightwater nuclear power 
reactors for normal operation,'' pursuant to 10 CFR 50.12, ``Specific 
exemptions.''
    Part 50, appendix G requires that pressure-temperature (P-T) limits 
be established for RPVs during normal operating and hydrostatic or leak 
rate testing conditions. Specifically, 10 CFR part 50, appendix G 
states that ``[t]he minimum temperature requirements . . . pertain to 
the controlling material, which is either the material in the closure 
flange or the material in the beltline region with the highest 
reference temperature. . . . the minimum temperature requirements and 
the controlling material depend on the operating condition (i.e., 
hydrostatic pressure and leak tests, or normal operation including 
anticipated normal operational occurrences), the vessel pressure, 
whether fuel is in the vessel, and whether the core is critical. The 
metal temperature of the controlling material, in the region of the 
controlling material which has the least favorable combination of 
stress and temperature, must exceed the appropriate minimum temperature 
requirement for the condition and pressure of the vessel specified in 
Table 1 [of 10 CFR part 50, appendix G].'' Footnote 2 to Table 1 in 10 
CFR part 50, appendix G specifies that RPV minimum temperature 
requirements related to RPV closure flange considerations shall be 
based on ``[t]he highest reference temperature of the material in the 
closure flange region that is highly stressed by bolt preload.''
    By letter dated July 24, 2014, NextEra submitted a license 
amendment request (LAR) to implement a revision of the P-T operating 
limits for Seabrook. In requesting the revisions to the P-T operating 
limits, the licensee referenced a topical report with a methodology 
that did not meet some of the requirements of 10 CFR part 50, appendix 
G, thus requiring the exemption pursuant to 10 CFR 50.12. Specifically, 
the exemption would permit use of an alternate methodology contained in 
WCAP-17444-P, Revision 0 (ADAMS Accession No. ML14216A406), ``Reactor 
Vessel Closure Head/Vessel Flange Requirements Evaluation for Seabrook, 
Unit 1,'' October 2011. The exemption would permit the methodology 
contained in WCAP-17444-P, in lieu of the specific requirements of 10 
CFR part 50, appendix G, related to the establishment of minimum 
temperature criteria for all modes of reactor operation addressed by 
Table 1 of 10 CFR part 50, appendix G, that are based on the properties 
of the material of the RPV closure flange region, that is highly 
stressed by the bolt preload for pressures greater than 20 percent of 
the pre-service hydrostatic test pressure. A non-proprietary version of 
WCAP-17444-P is available in ADAMS under Accession No. ML14216A406. The 
requirements from which NextEra requested that Seabrook be exempted 
shall be referred to, for the purpose of this exemption, as those 
requirements related to the application of footnote (2) to Table 1 of 
10 CFR part 50, appendix G, for pressures greater than 20 percent of 
the pre-service hydrostatic test pressure. The licensee did not request 
exemption from those requirements related to the application of 
footnote (2) to Table 1 of 10 CFR part 50, appendix G, for pressures 
less than or equal to 20 percent of the pre-service hydrostatic test 
pressure. These minimum temperature requirements (hereafter referred to 
as the minimum bolt-up temperature requirements) shall remain in effect 
for the Technical Specification (TS) P-T limit curves for all modes of 
reactor operation.
    WCAP-17444-P documents a linear elastic fracture mechanics (LEFM) 
analysis of postulated flaws in the Seabrook RPV closure flange region 
under normal operating conditions associated with RPV bolt-up, the 100

[[Page 46067]]

degrees Fahrenheit ([deg]F) per hour reactor coolant system (RCS) heat-
up transient, and the 100[emsp14][deg]F per hour cool-down transient. 
The LEFM analysis was performed by first calculating through-wall 
stress distributions for the flange region based on a finite element 
analysis (FEA) for bolt-up and the 100[emsp14][deg]F per hour heat-up 
and cool-down transients. The RCS heat-up and cool-down transients were 
evaluated by calculating the flange stresses as RCS pressure and 
temperature vary with time. The pressure and temperature changes were 
modeled based on realistic 100[emsp14][deg]F per hour heat-up and cool-
down transients that would be considered permissible for normal 
operating conditions based on the TS P-T limit curves. Therefore, the 
stress at any given temperature is based on a lower pressure than the 
limiting pressure from the proposed TS P-T limit curve, which is based 
on the limiting RPV beltline material properties and minimum bolt-up 
temperature requirement. The pressures used are those that are actually 
achievable based on physical properties of the reactor coolant during 
the heat-up process and the plant operating configuration, rather than 
what is permitted by the American Society of Mechanical Engineers 
Boiler and Pressure Vessel Code (ASME Code), Section XI, Appendix G, P-
T limits that are calculated based on the beltline material properties.
    The NRC concluded in its safety evaluation (SE) (ADAMS Accession 
No. ML15205A333) that the licensee has demonstrated that the 
combination of high stresses along with low metal temperature in the 
RPV flange region cannot exist simultaneously, based on the NRC staff's 
evaluation of WCAP-17444-P and the licensee's RAI responses. The NRC 
staff determined that the licensee also demonstrated that the 
structural integrity of the Seabrook RPV closure flange materials will 
not be challenged by facility operation in accordance with the proposed 
TS P-T limit curves that are based on the Seabrook RPV beltline region 
and the flange minimum bolt-up temperature, without the minimum 
temperature requirements related to Footnote (2) to Table 1 of 10 CFR 
part 50, appendix G for pressures greater than 20 percent of the pre-
service hydrostatic test pressure.
    Therefore, for pressures greater than 20 percent of the pre-service 
hydrostatic test pressure, the minimum temperature requirements related 
to Footnote (2) to Table 1 of 10 CFR part 50, appendix G are not 
necessary to meet the underlying intent of 10 CFR part 50, appendix G, 
to protect the Seabrook RPV closure flange from brittle fracture during 
normal operation under both core critical and core non-critical 
conditions and RPV hydrostatic and leak test conditions.

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: (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. Under 10 CFR 
50.12(a)(2)(ii), special circumstances include, among other things, 
when application of the specific regulation in the particular 
circumstance would not serve, or is not necessary to achieve, the 
underlying purpose of the rule. The NRC staff's detailed review and 
technical basis for the approval of the exemption, requested by 
NextEra, is provided in the NRC staff's SE (ADAMS Accession No. 
ML15205A333).

A. The Exemption Is Authorized by Law

    This exemption would allow the use of WCAP-17444-P, Revision 0, 
``Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for 
Seabrook Unit 1,'' in lieu of the minimum temperature requirement that 
is based on the highest reference temperature of the material in the 
closure flange region that is highly stressed by the bolt preload, for 
pressures greater than 20 percent of the pre-service hydrostatic test 
pressure, as required by 10 CFR part 50, appendix G, Table 1. As stated 
previously, 10 CFR 50.12(a)(2) allows the NRC to grant exemptions from 
the requirements of 10 CFR part 50, appendix G, provided that special 
circumstances are present. As described below, the NRC staff has 
determined that special circumstances exist to grant the requested 
exemption. In addition, granting the exemption will not result in a 
violation of the Atomic Energy Act of 1954, as amended, or NRC's 
regulations. Therefore, the exemption is authorized by law.

B. The Exemption Presents No Undue Risk to Public Health and Safety

    The revised P-T limit curves developed for Seabrook reference the 
methodology described in WCAP-17444-P, as the technical basis for 
eliminating the minimum temperature requirement for the flange for 
pressures greater than 20 percent of the pre-service hydrostatic test 
pressure. The WCAP-17444-P methodology uses a higher material fracture 
toughness, KIc (fracture toughness based on the lower bound 
of static initiation critical values measured as a function of 
temperature) instead of Kla (fracture toughness based upon 
the lower bound of crack arrest critical values measured as a function 
of temperature), which results in less restrictive operating conditions 
for the flange than those required by Table 1 of 10 CFR part 50, 
appendix G, for pressures greater than 20 percent of the pre-service 
hydrostatic test pressure. The regulations in 10 CFR part 50, appendix 
G, address the metal temperature of the closure head flange and vessel 
flange regions. The regulation states, in part, that the metal 
temperature of the closure flange regions must exceed the material un-
irradiated nil-ductility reference temperature (RTNDT) by at 
least 120[emsp14][deg]F for normal operation when the pressure exceeds 
20 percent of the pre-service hydrostatic test pressure.
    Implementing the P-T limit curves that use the KIc 
material fracture toughness without eliminating the flange requirement 
of 10 CFR part 50, appendix G, would place a restricted operating 
window in the temperature range associated with the flange/closure head 
(i.e., flange RTNDT + 120[emsp14][deg]F). In accordance with 
WCAP-17444-P, the KIc toughness has been shown to provide 
significant margin between the applied stress intensity factor and the 
fracture toughness of the flange/closure head. Applying the WCAP-17444-
P methodology for eliminating the flange minimum temperature 
requirement in the P-T limits, for pressures greater than 20 percent of 
the pre-service hydrostatic test pressure, will enhance overall plant 
safety by expanding the P-T operating window, especially in the region 
of low temperature operations.
    The two primary safety benefits that would be realized are a 
reduction in the potential challenges to the cold overpressure 
mitigation system, and a reduction in the risk of damaging the reactor 
coolant pump seals. This will produce a significant improvement in 
plant safety by reducing the probability of an inadvertent reduction in 
reactor coolant inventory and in easing the burden on the operators. 
WCAP-17444-P concludes that the integrity of the closure head/flange is 
not a concern for safe unit operation and testing. Therefore, the 
proposed exemption does not present an undue risk to the public health 
and safety.

C. The Exemption Is Consistent With the Common Defense and Security

    The licensee requested an exemption to use WCAP-17444-P in lieu of 
the

[[Page 46068]]

minimum temperature requirement that is based on the highest reference 
temperature of the material in the closure flange region that is highly 
stressed by the bolt preload, for pressures greater than 20 percent of 
the pre-service hydrostatic test pressure, as required by 10 CFR part 
50, appendix G, Table 1. This exemption request is not related to, and 
does not impact, any security issues at Seabrook. Therefore, the NRC 
staff determined that this exemption does not impact, and is consistent 
with, the common defense and security.

D. 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 50.60 and 10 CFR part 50, 
appendix G, is to protect the integrity of the reactor coolant pressure 
boundary. The regulations in 10 CFR part 50, appendix G, establish the 
requirements for the P-T limits for pressure retaining components of 
the reactor coolant pressure boundary and requirements for the minimum 
metal temperature of the RPV closure head flange and reactor vessel 
flange regions. The P-T limits are determined using the methodology of 
the ASME Code, Section Xl, Appendix G, with additional, more 
restrictive, flange temperature requirements specified in 10 CFR part 
50, appendix G.
    The NRC staff examined the licensee's rationale to support the 
exemption request. Based on its consideration of the information 
provided in WCAP-17444-P and the information provided in the licensee's 
letters dated April 24 and June 24, 2015, an acceptable technical basis 
has been established to exempt Seabrook from the requirements related 
to Footnote 2 to Table 1 of 10 CFR part 50, appendix G, for RCS 
pressures greater than 20 percent of the pre-service hydrostatic test 
pressure. The technical basis provided by the licensee has established 
that an adequate margin of safety against brittle failure would 
continue to be maintained for the Seabrook RPV without the application 
of those requirements related to Footnote 2 to Table 1 of 10 CFR part 
50, appendix G, for normal operation under both core critical and core 
non-critical conditions and RPV hydrostatic and leak test conditions, 
for RCS pressures greater than 20 percent of the pre-service 
hydrostatic test pressure.
    Therefore, the special circumstances required by 10 CFR 
50.12(a)(2)(ii) for the granting of an exemption exist.

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 issuance 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 staff'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 whether the exemption involves 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 probability or consequences of an accident previously evaluated?
    Response: No.
    The proposed exemption does not impact the physical function of 
plant structures, systems, or components (SSCs) or the manner in 
which SSCs perform their design function. Operation in accordance 
with the proposed WCAP-17444 will ensure that all analyzed accidents 
will continue to be mitigated by the SSCs as previously analyzed. 
The proposed exemption does not alter or prevent the ability of 
operable SSCs to perform their intended function to mitigate the 
consequences of an initiating event within assumed acceptance 
limits. The proposed exemption neither adversely affects accident 
initiators or precursors, nor alter design assumptions.
    Therefore, this 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?
    Response: No.
    The proposed exemption does not involve a physical alteration of 
the plant (i.e., no new or different type of equipment will be 
installed), does not create new failure modes for existing 
equipment, or create any new limiting single failures. The exemption 
will continue to ensure that appropriate fracture toughness margins 
are maintained to protect against reactor vessel failure, during 
both normal and low temperature operation. The proposed exemption is 
consistent with the applicable NRC approved methodologies (i.e., 
WCAP-17444-P, Revision 0). Plant operation will not be altered, and 
all safety functions will continue to perform as previously assumed 
in accident analyses.
    Therefore, this exemption does not create the possibility of a 
new or different kind of accident from an accident previously 
evaluated.
    3. Does the proposed exemption involve a significant reduction 
in a margin of safety?
    Response: No.

    Margin of safety is associated with confidence in the ability of 
the fission product barriers (i.e., fuel cladding, reactor coolant 
system pressure boundary, and containment structure) to limit the level 
of radiation dose to the public. The proposed exemption will not 
adversely affect the operation of plant equipment or the function of 
any equipment assumed in the accident analysis. The proposed exemption 
was developed using NRC-approved methodologies and will continue to 
ensure an acceptable margin of safety is maintained. The safety 
analysis acceptance criteria are not affected by this exemption. The 
proposed exemption will not result in plant operation in a 
configuration outside the design basis. The proposed exemption does not 
adversely affect systems that respond to safely shut down the plant and 
to maintain the plant in a safe shutdown condition.
    Therefore, this exemption does not involve a significant reduction 
in a margin of safety.
    Based on the above evaluation of the standards set forth in 10 CFR 
50.92(c), the NRC staff concludes that the proposed exemption involves 
no significant hazards consideration. Accordingly, the requirements of 
10 CFR 51.22(c)(9)(i) are met.
Requirements in 10 CFR 51.22(c)(9)(ii)
    The proposed exemption would allow the use of WCAP-17444-P, 
Revision 0, in lieu of the highest reference temperature of the 
material in the closure flange region that is highly stressed by the 
bolt preload required by 10 CFR part 50, appendix G, Table 1. WCAP-
17444 demonstrates that the flange region can tolerate assumed flaws of 
0.1 T (thickness) during the heat-up, cool-down, and bolt-up 
conditions. Additionally, it can be concluded that flaws are unlikely 
to initiate in the flange region, since there is no known degradation 
mechanism for the flange region and the fatigue usage in the flange 
region is less than 0.1 T. Furthermore, based on WCAP-17444,

[[Page 46069]]

the alternative flange temperature requirement of 46[emsp14][deg]F is 
less than the minimum bolt-up temperature of 60[emsp14][deg]F for 
Seabrook. Therefore, the proposed exemption 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 requirements 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 WCAP-17444-P, 
Revision 0, in lieu of the methodology required by 10 CFR part 50, 
appendix G, Footnote (2), to Table 1. Therefore, the proposed exemption 
will not significantly increase individual occupational radiation 
exposure or significantly increase cumulative occupational radiation 
exposure. Therefore, the requirements of 10 CFR 51.22(c)(9)(iii) are 
met.
Conclusion
    Based on the above, the NRC staff concludes that the proposed 
exemption meets the eligibility criteria for the categorical exclusion 
set forth in 10 CFR 51.22(c)(9). 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 issuance of this 
exemption.

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, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants the licensee an exemption from 
10 CFR 50.60 to permit the use of WCAP-17444-P in lieu of the highest 
reference temperature of the material in the closure flange region that 
is highly stressed by the bolt preload required by 10 CFR 50, Appendix 
G, Table 1 for Seabrook. This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 28th day of July 2015.

    For the Nuclear Regulatory Commission.

George Wilson,
Acting Director, Division of Operating Reactor Licensing, Office of 
Nuclear Reactor Regulation.
[FR Doc. 2015-19003 Filed 7-31-15; 8:45 am]
BILLING CODE 7590-01-P
Federal Register / Vol. 80, No. 148 / Monday, August 3, 2015 / Notices 46067

degrees Fahrenheit (°F) per hour reactor normal operation under both core higher material fracture toughness, KIc
coolant system (RCS) heat-up transient, critical and core non-critical conditions (fracture toughness based on the lower
and the 100 °F per hour cool-down and RPV hydrostatic and leak test bound of static initiation critical values
transient. The LEFM analysis was conditions. measured as a function of temperature)
performed by first calculating through- instead of Kla (fracture toughness based
III. Discussion
wall stress distributions for the flange upon the lower bound of crack arrest
region based on a finite element analysis Pursuant to 10 CFR 50.12, the critical values measured as a function of
(FEA) for bolt-up and the 100 °F per Commission may, upon application by temperature), which results in less
hour heat-up and cool-down transients. any interested person or upon its own restrictive operating conditions for the
The RCS heat-up and cool-down initiative, grant exemptions from the flange than those required by Table 1 of
transients were evaluated by calculating requirements of 10 CFR part 50 when: 10 CFR part 50, appendix G, for
the flange stresses as RCS pressure and (1) The exemptions are authorized by pressures greater than 20 percent of the
temperature vary with time. The law, will not present an undue risk to pre-service hydrostatic test pressure.
pressure and temperature changes were public health or safety, and are The regulations in 10 CFR part 50,
modeled based on realistic 100 °F per consistent with the common defense appendix G, address the metal
hour heat-up and cool-down transients and security; and (2) when special temperature of the closure head flange
that would be considered permissible circumstances are present. Under 10 and vessel flange regions. The
for normal operating conditions based CFR 50.12(a)(2)(ii), special regulation states, in part, that the metal
on the TS P–T limit curves. Therefore, circumstances include, among other temperature of the closure flange
the stress at any given temperature is things, when application of the specific regions must exceed the material un-
based on a lower pressure than the regulation in the particular irradiated nil-ductility reference
limiting pressure from the proposed TS circumstance would not serve, or is not temperature (RTNDT) by at least 120 °F
P–T limit curve, which is based on the necessary to achieve, the underlying for normal operation when the pressure
limiting RPV beltline material purpose of the rule. The NRC staff’s exceeds 20 percent of the pre-service
properties and minimum bolt-up detailed review and technical basis for hydrostatic test pressure.
temperature requirement. The pressures the approval of the exemption, Implementing the P–T limit curves
used are those that are actually requested by NextEra, is provided in the that use the KIc material fracture
achievable based on physical properties NRC staff’s SE (ADAMS Accession No. toughness without eliminating the
of the reactor coolant during the heat-up ML15205A333). flange requirement of 10 CFR part 50,
process and the plant operating A. The Exemption Is Authorized by Law appendix G, would place a restricted
configuration, rather than what is operating window in the temperature
permitted by the American Society of This exemption would allow the use range associated with the flange/closure
Mechanical Engineers Boiler and of WCAP–17444–P, Revision 0, ‘‘Reactor head (i.e., flange RTNDT + 120 °F). In
Pressure Vessel Code (ASME Code), Vessel Closure Head/Vessel Flange accordance with WCAP–17444–P, the
Section XI, Appendix G, P–T limits that Requirements Evaluation for Seabrook KIc toughness has been shown to
are calculated based on the beltline Unit 1,’’ in lieu of the minimum provide significant margin between the
material properties. temperature requirement that is based applied stress intensity factor and the
The NRC concluded in its safety on the highest reference temperature of fracture toughness of the flange/closure
evaluation (SE) (ADAMS Accession No. the material in the closure flange region head. Applying the WCAP–17444–P
ML15205A333) that the licensee has that is highly stressed by the bolt methodology for eliminating the flange
demonstrated that the combination of preload, for pressures greater than 20 minimum temperature requirement in
high stresses along with low metal percent of the pre-service hydrostatic the P–T limits, for pressures greater than
temperature in the RPV flange region test pressure, as required by 10 CFR part 20 percent of the pre-service hydrostatic
cannot exist simultaneously, based on 50, appendix G, Table 1. As stated test pressure, will enhance overall plant
the NRC staff’s evaluation of WCAP– previously, 10 CFR 50.12(a)(2) allows safety by expanding the P–T operating
17444–P and the licensee’s RAI the NRC to grant exemptions from the window, especially in the region of low
responses. The NRC staff determined requirements of 10 CFR part 50, temperature operations.
that the licensee also demonstrated that appendix G, provided that special The two primary safety benefits that
the structural integrity of the Seabrook circumstances are present. As described would be realized are a reduction in the
RPV closure flange materials will not be below, the NRC staff has determined potential challenges to the cold
challenged by facility operation in that special circumstances exist to grant overpressure mitigation system, and a
accordance with the proposed TS P–T the requested exemption. In addition, reduction in the risk of damaging the
limit curves that are based on the granting the exemption will not result in reactor coolant pump seals. This will
Seabrook RPV beltline region and the a violation of the Atomic Energy Act of produce a significant improvement in
flange minimum bolt-up temperature, 1954, as amended, or NRC’s regulations. plant safety by reducing the probability
without the minimum temperature Therefore, the exemption is authorized of an inadvertent reduction in reactor
requirements related to Footnote (2) to by law. coolant inventory and in easing the
Table 1 of 10 CFR part 50, appendix G burden on the operators. WCAP–17444–
B. The Exemption Presents No Undue
for pressures greater than 20 percent of P concludes that the integrity of the
Risk to Public Health and Safety
the pre-service hydrostatic test pressure. closure head/flange is not a concern for
Therefore, for pressures greater than The revised P–T limit curves safe unit operation and testing.
mstockstill on DSK4VPTVN1PROD with NOTICES

20 percent of the pre-service hydrostatic developed for Seabrook reference the Therefore, the proposed exemption does
test pressure, the minimum temperature methodology described in WCAP– not present an undue risk to the public
requirements related to Footnote (2) to 17444–P, as the technical basis for health and safety.
Table 1 of 10 CFR part 50, appendix G eliminating the minimum temperature
are not necessary to meet the underlying requirement for the flange for pressures C. The Exemption Is Consistent With the
intent of 10 CFR part 50, appendix G, greater than 20 percent of the pre- Common Defense and Security
to protect the Seabrook RPV closure service hydrostatic test pressure. The The licensee requested an exemption
flange from brittle fracture during WCAP–17444–P methodology uses a to use WCAP–17444–P in lieu of the

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46068 Federal Register / Vol. 80, No. 148 / Monday, August 3, 2015 / Notices

minimum temperature requirement that E. Environmental Considerations toughness margins are maintained to protect
is based on the highest reference against reactor vessel failure, during both
The NRC staff determined that the normal and low temperature operation. The
temperature of the material in the exemption discussed herein meets the proposed exemption is consistent with the
closure flange region that is highly eligibility criteria for the categorical applicable NRC approved methodologies
stressed by the bolt preload, for exclusion set forth in 10 CFR (i.e., WCAP–17444–P, Revision 0). Plant
pressures greater than 20 percent of the 51.22(c)(9), because it is related to a operation will not be altered, and all safety
pre-service hydrostatic test pressure, as requirement concerning the installation functions will continue to perform as
required by 10 CFR part 50, appendix G, or use of a facility component located previously assumed in accident analyses.
Table 1. This exemption request is not within the restricted area, as defined in Therefore, this exemption does not create
related to, and does not impact, any the possibility of a new or different kind of
10 CFR part 20, and issuance of this accident from an accident previously
security issues at Seabrook. Therefore, exemption involves (i) no significant
the NRC staff determined that this evaluated.
hazards consideration, (ii) no significant 3. Does the proposed exemption involve a
exemption does not impact, and is change in the types or a significant significant reduction in a margin of safety?
consistent with, the common defense increase in the amounts of any effluents Response: No.
and security.
that may be released offsite, and (iii) no Margin of safety is associated with
D. Special Circumstances significant increase in individual or confidence in the ability of the fission
Special circumstances, in accordance cumulative occupational radiation product barriers (i.e., fuel cladding,
with 10 CFR 50.12(a)(2)(ii), are present exposure. Therefore, in accordance with reactor coolant system pressure
whenever application of the regulation 10 CFR 51.22(b), no environmental boundary, and containment structure) to
in the particular circumstances is not impact statement or environmental limit the level of radiation dose to the
necessary to achieve the underlying assessment need to be prepared in public. The proposed exemption will
purpose of the rule. The underlying connection with the NRC staff’s not adversely affect the operation of
purpose of 10 CFR 50.60 and 10 CFR consideration of this exemption request. plant equipment or the function of any
part 50, appendix G, is to protect the The basis for the NRC staff’s equipment assumed in the accident
integrity of the reactor coolant pressure determination is discussed as follows, analysis. The proposed exemption was
boundary. The regulations in 10 CFR with an evaluation against each of the developed using NRC-approved
part 50, appendix G, establish the requirements in 10 CFR 51.22(c)(9)(i)– methodologies and will continue to
requirements for the P–T limits for (iii). ensure an acceptable margin of safety is
pressure retaining components of the Requirements in 10 CFR 51.22(c)(9)(i) maintained. The safety analysis
reactor coolant pressure boundary and acceptance criteria are not affected by
requirements for the minimum metal The NRC staff evaluated whether the this exemption. The proposed
temperature of the RPV closure head exemption involves no significant exemption will not result in plant
flange and reactor vessel flange regions. hazards consideration using the operation in a configuration outside the
The P–T limits are determined using the standards described in 10 CFR 50.92(c), design basis. The proposed exemption
methodology of the ASME Code, as presented below: does not adversely affect systems that
Section Xl, Appendix G, with 1. Does the proposed exemption involve a respond to safely shut down the plant
additional, more restrictive, flange significant increase in the probability or and to maintain the plant in a safe
temperature requirements specified in consequences of an accident previously shutdown condition.
10 CFR part 50, appendix G. evaluated?
Therefore, this exemption does not
Response: No.
The NRC staff examined the licensee’s The proposed exemption does not impact involve a significant reduction in a
rationale to support the exemption the physical function of plant structures, margin of safety.
request. Based on its consideration of systems, or components (SSCs) or the manner Based on the above evaluation of the
the information provided in WCAP– in which SSCs perform their design function. standards set forth in 10 CFR 50.92(c),
17444–P and the information provided Operation in accordance with the proposed the NRC staff concludes that the
in the licensee’s letters dated April 24 WCAP–17444 will ensure that all analyzed proposed exemption involves no
and June 24, 2015, an acceptable accidents will continue to be mitigated by the significant hazards consideration.
technical basis has been established to SSCs as previously analyzed. The proposed
Accordingly, the requirements of 10
exemption does not alter or prevent the
exempt Seabrook from the requirements ability of operable SSCs to perform their CFR 51.22(c)(9)(i) are met.
related to Footnote 2 to Table 1 of 10 intended function to mitigate the
CFR part 50, appendix G, for RCS Requirements in 10 CFR 51.22(c)(9)(ii)
consequences of an initiating event within
pressures greater than 20 percent of the assumed acceptance limits. The proposed The proposed exemption would allow
pre-service hydrostatic test pressure. exemption neither adversely affects accident the use of WCAP–17444–P, Revision 0,
The technical basis provided by the initiators or precursors, nor alter design in lieu of the highest reference
licensee has established that an assumptions. temperature of the material in the
adequate margin of safety against brittle Therefore, this exemption does not involve closure flange region that is highly
a significant increase in the probability or
failure would continue to be maintained consequences of an accident previously
stressed by the bolt preload required by
for the Seabrook RPV without the evaluated. 10 CFR part 50, appendix G, Table 1.
application of those requirements 2. Does the proposed exemption create the WCAP–17444 demonstrates that the
related to Footnote 2 to Table 1 of 10 possibility of a new or different kind of flange region can tolerate assumed flaws
CFR part 50, appendix G, for normal accident from any accident previously of 0.1 T (thickness) during the heat-up,
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operation under both core critical and evaluated? cool-down, and bolt-up conditions.
core non-critical conditions and RPV Response: No. Additionally, it can be concluded that
The proposed exemption does not involve flaws are unlikely to initiate in the
hydrostatic and leak test conditions, for
a physical alteration of the plant (i.e., no new
RCS pressures greater than 20 percent of or different type of equipment will be
flange region, since there is no known
the pre-service hydrostatic test pressure. installed), does not create new failure modes degradation mechanism for the flange
Therefore, the special circumstances for existing equipment, or create any new region and the fatigue usage in the
required by 10 CFR 50.12(a)(2)(ii) for the limiting single failures. The exemption will flange region is less than 0.1 T.
granting of an exemption exist. continue to ensure that appropriate fracture Furthermore, based on WCAP–17444,

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Federal Register / Vol. 80, No. 148 / Monday, August 3, 2015 / Notices 46069

the alternative flange temperature POSTAL REGULATORY COMMISSION II. Notice of Commission Action
requirement of 46 °F is less than the The Commission establishes Docket
minimum bolt-up temperature of 60 °F [Docket Nos. MC2015–74 and CP2015–112; Nos. MC2015–74 and CP2015–112 to
for Seabrook. Therefore, the proposed Order No. 2616] consider the Request pertaining to the
exemption will not significantly change proposed Priority Mail Contract 138
the types of effluents that may be New Postal Product product and the related contract,
released offsite, or significantly increase respectively.
the amount of effluents that may be AGENCY: Postal Regulatory Commission.
The Commission invites comments on
released offsite. Therefore, the ACTION: Notice. whether the Postal Service’s filings in
requirements of 10 CFR 51.22(c)(9)(ii) the captioned dockets are consistent
are met. SUMMARY: The Commission is noticing a
recent Postal Service filing concerning with the policies of 39 U.S.C. 3632,
Requirements in 10 CFR 51.22(c)(9)(iii) the addition of Priority Mail Contract 3633, or 3642, 39 CFR part 3015, and 39
138 negotiated service agreement to the CFR part 3020, subpart B. Comments are
The proposed exemption would allow competitive product list. This notice due no later than August 4, 2015. The
the use of WCAP–17444–P, Revision 0, informs the public of the filing, invites public portions of these filings can be
in lieu of the methodology required by public comment, and takes other accessed via the Commission’s Web site
10 CFR part 50, appendix G, Footnote administrative steps. (http://www.prc.gov).
(2), to Table 1. Therefore, the proposed The Commission appoints Lyudmila
DATES: Comments are due: August 4,
exemption will not significantly Y. Bzhilyanskaya to serve as Public
increase individual occupational 2015. Representative in these dockets.
radiation exposure or significantly ADDRESSES: Submit comments III. Ordering Paragraphs
increase cumulative occupational electronically via the Commission’s
radiation exposure. Therefore, the Filing Online system at http:// It is ordered:
requirements of 10 CFR 51.22(c)(9)(iii) www.prc.gov. Those who cannot submit 1. The Commission establishes Docket
are met. comments electronically should contact Nos. MC2015–74 and CP2015–112 to
the person identified in the FOR FURTHER consider the matters raised in each
Conclusion docket.
INFORMATION CONTACT section by
Based on the above, the NRC staff telephone for advice on filing 2. Pursuant to 39 U.S.C. 505,
concludes that the proposed exemption alternatives. Lyudmila Y. Bzhilyanskaya is appointed
meets the eligibility criteria for the to serve as an officer of the Commission
FOR FURTHER INFORMATION CONTACT:
categorical exclusion set forth in 10 CFR to represent the interests of the general
David A. Trissell, General Counsel, at public in these proceedings (Public
51.22(c)(9). Therefore, in accordance 202–789–6820.
with 10 CFR 51.22(b), no environmental Representative).
SUPPLEMENTARY INFORMATION: 3. Comments are due no later than
impact statement or environmental
assessment need be prepared in Table of Contents August 4, 2015.
connection with the NRC’s issuance of 4. The Secretary shall arrange for
I. Introduction publication of this order in the Federal
this exemption. II. Notice of Commission Action Register.
III. Ordering Paragraphs
IV. Conclusions By the Commission.
I. Introduction Ruth Ann Abrams,
Accordingly, the Commission has
determined that pursuant to 10 CFR In accordance with 39 U.S.C. 3642 Acting Secretary.
50.12(a), the exemption is authorized by and 39 CFR 3020.30 et seq., the Postal [FR Doc. 2015–18861 Filed 7–31–15; 8:45 am]
law, will not present an undue risk to Service filed a formal request and BILLING CODE 7710–FW–P
the public health and safety, and is associated supporting information to
consistent with the common defense add Priority Mail Contract 138 to the
and security. Also, special competitive product list.1 POSTAL REGULATORY COMMISSION
circumstances are present. Therefore, The Postal Service
[Docket Nos. MC2015–73 and CP2015–111;
the Commission hereby grants the contemporaneously filed a redacted Order No. 2615]
licensee an exemption from 10 CFR contract related to the proposed new
50.60 to permit the use of WCAP– product under 39 U.S.C. 3632(b)(3) and New Postal Product
17444–P in lieu of the highest reference 39 CFR 3015.5. Id. Attachment B.
temperature of the material in the To support its Request, the Postal AGENCY: Postal Regulatory Commission.
closure flange region that is highly Service filed a copy of the contract, a ACTION: Notice.
stressed by the bolt preload required by copy of the Governors’ Decision
10 CFR 50, Appendix G, Table 1 for authorizing the product, proposed SUMMARY: The Commission is noticing a
Seabrook. This exemption is effective changes to the Mail Classification recent Postal Service filing concerning
upon issuance. Schedule, a Statement of Supporting the addition of Priority Mail Contract
Justification, a certification of 137 negotiated service agreement to the
Dated at Rockville, Maryland, this 28th day competitive product list. This notice
compliance with 39 U.S.C. 3633(a), and
of July 2015. informs the public of the filing, invites
an application for non-public treatment
mstockstill on DSK4VPTVN1PROD with NOTICES

For the Nuclear Regulatory Commission. of certain materials. It also filed public comment, and takes other
George Wilson, supporting financial workpapers. administrative steps.
Acting Director, Division of Operating Reactor DATES: Comments are due: August 4,
Licensing, Office of Nuclear Reactor 1 Request of the United States Postal Service to 2015.
Regulation. Add Priority Mail Contract 138 to Competitive
Product List and Notice of Filing (Under Seal) of
ADDRESSES: Submit comments
[FR Doc. 2015–19003 Filed 7–31–15; 8:45 am] electronically via the Commission’s
Unredacted Governors’ Decision, Contract, and
BILLING CODE 7590–01–P Supporting Data, July 27, 2015 (Request). Filing Online system at http://

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Document Created: 2018-02-23 10:51:29
Document Modified: 2018-02-23 10:51:29
Category		Regulatory Information
Collection		Federal Register
sudoc Class		AE 2.7: GS 4.107: AE 2.106:
Publisher		Office of the Federal Register, National Archives and Records Administration
Section		Notices
Action		Exemption; issuance.
Contact		John G. Lamb, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: 301-415-3100, email: [email protected]
FR Citation		80 FR 46066