Proposed License Renewal Interim Staff Guidance LR-ISG-2007-02: Changes to Generic Aging Lesson Learned (GALL) Report Aging Management Program (AMP) XI.E6, “Electrical Cable Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements” Solicitation of Public Comment, 51256-51259 [E7-17616]
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51256
Federal Register / Vol. 72, No. 172 / Thursday, September 6, 2007 / Notices
located in ADAMS should contact the
NRC PDR Reference staff by telephone
at 1–800–397–4209, or 301–415–4737 or
by e-mail to pdr@nrc.gov.
Dated at Rockville, Maryland, this 29th day
of August 2007.
For the Nuclear Regulatory Commission.
Richard B. Ennis,
Senior Project Manager, Plant Licensing
Branch I–2, Division of Operating Reactor
Licensing, Office of Nuclear Reactor
Regulation.
[FR Doc. E7–17606 Filed 9–5–07; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
Proposed License Renewal Interim
Staff Guidance LR–ISG–2007–02:
Changes to Generic Aging Lesson
Learned (GALL) Report Aging
Management Program (AMP) XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements’’
Solicitation of Public Comment
U.S. Nuclear Regulatory
Commission.
ACTION: Solicitation of public comment.
mstockstill on PROD1PC66 with NOTICES
AGENCY:
SUMMARY: The U.S. Nuclear Regulatory
Commission (NRC) is soliciting public
comment on its Proposed License
Renewal Interim Staff Guidance LR–
ISG–2007–02 (LR–ISG) for changes to its
Generic Aging Lesson Learned (GALL)
Report Aging Management Program
(AMP) XI.E6, ‘‘Electrical Cable
Connections Not Subject to 10 CFR
50.49 Environmental Qualification
Requirements.’’ This LR–ISG clarifies
and recommends a one-time inspection
to ensure that either aging of metallic
cable connections is not occurring or an
existing preventive maintenance
program is effective, such that a
periodic inspection is not needed. The
NRC staff issues LR–ISGs to facilitate
timely implementation of the license
renewal rule and to review activities
associated with an LRA. Upon receiving
public comments, the NRC staff will
evaluate the comments and make a
determination to incorporate the
comments, as appropriate. Once the
NRC staff completes the LR–ISG, it will
issue the LR–ISG for NRC and industry
use. The NRC staff will also incorporate
the approved LR–ISG into the next
revision of the license renewal guidance
documents.
DATES: Comments may be submitted by
October 22, 2007. Comments received
after this date will be considered, if it
is practical to do so, but the
Commission is able to ensure
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18:25 Sep 05, 2007
Jkt 211001
consideration only for comments
received on or before this date.
ADDRESSES: Comments may be
submitted to: Chief, Rulemaking,
Directives, and Editing Branch, Office of
Administration, U.S. Nuclear Regulatory
Commission, Washington, DC 20555–
0001. Comments should be delivered to:
11545 Rockville Pike, Rockville,
Maryland, Room T–6D59, between 7:30
a.m. and 4:15 p.m. on Federal workdays.
Persons may also provide comments via
e-mail at NRCREP@NRC.GOV. The NRC
maintains an Agencywide Documents
Access and Management System
(ADAMS), which provides text and
image files of NRC’s public documents.
These documents may be accessed
through the NRC’s Public Electronic
Reading Room on the Internet at http:
//www.nrc.gov/reading-rm/adams.html.
Persons who do not have access to
ADAMS or who encounter problems in
accessing the documents located in
ADAMS should contact the NRC Public
Document Room (PDR) reference staff at
1–800–397–4209, 301–415–4737, or by
e-mail at pdr@nrc.gov.
FOR FURTHER INFORMATION CONTACT: Ms.
Linh Tran, Project Manager, Office of
Nuclear Reactor Regulation, U.S.
Nuclear Regulatory Commission,
Washington, DC 20555–0001; telephone
301–415–4103 or by e-mail at
Int@nrc.gov.
SUPPLEMENTARY INFORMATION:
Attachment 1 to this Federal Register
notice, entitled Staff Position and
Rationale for the Proposed License
Renewal Interim Staff Guidance LR–
ISG–2007–02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging
Management Program (AMP) XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements,’’ contains
the NRC staff’s rationale for publishing
the proposed LR–ISG–2007–02.
Attachment 2 to this Federal Register
notice, entitled Proposed License
Renewal Interim Staff Guidance LR–
ISG–2007–02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging
Management Program (AMP) XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements,’’ contains
the proposed revisions to GALL AMP
XI.E6.
The NRC staff is issuing this notice to
solicit public comments on the
proposed LR–ISG–2007–02. After the
NRC staff considers any public
comments, it will make a determination
regarding issuance of the proposed LR–
ISG.
For the Nuclear Regulatory Commission.
Pao-Tsin Kuo,
Director, Division of License Renewal, Office
of Nuclear Reactor Regulation.
Attachment 1—Staff Position and
Rationale for the Proposed License
Renewal Interim Staff Guidance LR–
ISG–2007–02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging
Management Program (AMP) XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements’’
Staff Position
The staff is proposing to revise GALL
AMP XI.E6 to recommend a one-time
inspection for electrical cable
connections not subject to 10 CFR 50.49
environmental qualification
requirement instead of the period
inspection as currently stated in GALL
AMP XI.E6. The staff determined that
this one-time inspection, on
representative sample basis, is adequate
to ensure that either aging of metallic
cable connections is not occurring and/
or existing preventive maintenance
program is effective such that a periodic
inspection program is not needed.
Rationale
In reviewing the industry’s
documents and comments, the staff
determined that although the current
GALL AMP XI.E6 was based on
technical bases of Electric Power
Research Institute documents, Sandia
National Laboratories Report, SAND 96–
0344, and thermography data, few
operating experiences related to failed
connection due to aging had been
identified. Most of the operating
experience related to failed connection
are due to human errors or maintenance
practices. The operating experience
cannot support a periodic inspection as
currently recommended in GALL AMP
XI.E6. However, because there have
been a limited number of age related
failures of cable connections, a one-time
inspection of the metallic portion of
electrical cable connections is
warranted. On this basis, the staff is
revising GALL AMP XI.E6 to clarify and
recommend a one-time inspection, on a
representative sampling basis, to ensure
that either aging of metallic cable
connections is not occurring or an
existing preventive maintenance
program is effective, such that a
periodic inspection is not needed.
Dated at Rockville, Maryland this 29th day
of August, 2007.
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Federal Register / Vol. 72, No. 172 / Thursday, September 6, 2007 / Notices
Attachment 2—Proposed License
Renewal Interim Staff Guidance LR–
ISG–2007–02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging
Management Program (AMP) XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements’’
mstockstill on PROD1PC66 with NOTICES
Introduction
Consistent with the requirements
specified in Title 10 of the Code of
Federal Regulations (10 CFR) Part 54,
Section 54.4(a), electrical cable
connections support safety-related and
non-safety-related functions in that the
failure of the electrical cable
connections precludes a function from
being accomplished (10 CFR 54.4(a)(1),
(a)(2), and (a)(3)).
Electrical cable connections exposed
to appreciable ohmic or ambient heating
during operation may experience
loosening caused by repeated cycling of
connected loads or of the ambient
temperature environment. Different
materials used in various cable system
components can produce situations
where stresses between these
components change with repeated
thermal cycling. For example, under
loaded conditions, ohmic heating may
raise the temperature of a compression
terminal and cable conductor well
above the ambient temperature, thereby
causing thermal expansion of both
components. Thermal expansion
coefficients of different materials may
alter mechanical stresses between the
components so that the termination may
be impacted. When the current is
reduced, the affected components cool
and contract. Repeated cycling in this
fashion can cause loosening of the
termination, and may lead to high
electrical resistance or eventual
separation of compression-type
terminations. Threaded connectors may
loosen if subjected to significant
thermally induced stress and cycling.
Because of the potential loosening of
bolted cable connections, the staff
included, in its updated license renewal
guidance documents, AMP XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements,’’ to manage
the potential aging of electrical cable
connections not subject to 10 CFR 50.49
environmental qualification
requirements.
Background and Discussion
The staff included AMP XI.E6,
‘‘Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental
Qualification Requirements,’’ in Chapter
XI of GALL Report, Revision 1, dated
September 2005. By letter dated
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18:25 Sep 05, 2007
Jkt 211001
September 5, 2006, (Agencywide
Documents Access and Management
System (ADAMS) Accession No.
ML062770105), Nuclear Energy Institute
(NEI) submitted a white paper regarding
GALL AMP XI.E6 (ADAMS Accession
No. ML062770111) . NEI stated that
there was not enough operating
experience to support a conclusion that
cable connections are a significant aging
concern and that the recommended
program elements of GALL AMP XI.E6
duplicate aging management activities
already defined and accepted in other
AMPs. NEI also stated that the
expanded scope of the program includes
all voltage ranges regardless of the
amount of evidence from operating
experience. In addition, NEI identified
wording in GALL AMP XI.E6 that
included connections in active
components. NEI asked the staff to
review its white paper to eliminate
GALL AMP XI.E6 or minimize its scope
and redundancy so that the plant would
not be burdened with activities that
have no actual aging management
benefit.
On November 30, 2006, the staff met
with NEI representatives to discuss the
white paper. In a letter dated March 16,
2007, (ADAMS Accession No.
ML070400349), the staff provided
responses to each of the industry’s
concerns identified in the white paper.
By letter dated May 25, 2007, (ADAMS
Accession Nos. ML071590175 and
ML071590182), NEI submitted
comments on the staff’s responses.
In reviewing the industry’s white
paper and comments, the staff
determined that although GALL AMP
XI.E6 was based on the technical bases
of Electric Power Research Institute
documents, and Sandia National
Laboratories Report, SAND 96–0344,
little operating experience related to
failed connections due to aging had
been identified. Most of the operating
experience related to failed connections
were due to human errors or
maintenance practices. The operating
experience cannot support the periodic
inspection recommended in AMP XI.E6
in GALL Report, Revision 1, dated
September 2005. However, because
there have been a limited number of age
related failures of cable connections, a
one-time inspection of the metallic
portion of electrical cable connections is
warranted. On this basis, the staff is
revising GALL AMP XI.E6 to clarify and
recommend a one-time inspection, on a
representative sampling, to ensure that
either aging of metallic cable
connections is not occurring or an
existing preventive maintenance
program is effective, such that a
periodic inspection is not required.
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51257
Proposed Action
The staff is proposing to revise GALL
AMP XI.E6 to recommend a one-time
inspection prior to the period of
extended operation for electrical cable
connections not subject to 10 CFR 50.49
EQ requirement instead of the periodic
inspection currently stated in GALL
AMP XI.E6. The staff determined that
this one-time inspection, on a
representative sample basis, is adequate
to ensure that either aging of metallic
cable connections is not occurring and/
or the existing preventive maintenance
program is effective so that a periodic
inspection program is not required. The
one-time inspection verifies that
loosening and/or high resistance of
cable connections due to thermal
cycling, ohmic heating, electrical
transients, vibration, chemical
contamination, corrosion, and oxidation
are not happening and periodic
inspections are not required. The onetime inspection should include testing
of a representative sample of the
electrical cable connection population
subject to an aging effect. The sample
should include each type of electrical
cable connection. The following factors
shall be considered for sampling:
voltage level (medium and low voltage),
circuit loading (high load), and location
(high temperature, high humidity,
vibration, etc.). The technical basis for
the sample selection should be
documented. The one-time inspection
will confirm that there are no aging
effects that require management during
the period of extended operation.
The applicant will take corrective
actions when acceptance criteria are not
met. Corrective actions may include, but
are not limited to sample expansion,
increased inspection frequency, and
replacement or repair of the affected
cable connection components.
When an applicant performs periodic
preventive maintenance that includes
inspection and testing of cable
connections, the applicant can credit
this maintenance activity toward GALL
AMP XI.E6. The applicant may also
revise its preventive maintenance
procedures to cover the inspection of
cable connections to take credit for
GALL AMP XI.E6.
Attached is the proposed revision to
GALL AMP XI.E6. Although this
proposed revision does not convey a
change in the regulations or how they
are being interpreted, it is being
provided to facilitate preparation of
future submittals in support of
applications for license renewal. This
LR–ISG provides a clarification of
existing guidance with no additional
requirements.
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Federal Register / Vol. 72, No. 172 / Thursday, September 6, 2007 / Notices
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Attachment—XI.E6 Electrical Cable
Connections Not Subject to 10 CFR
50.49 Environmental Qualification
Requirements (Revised)
Program Description
Cable connections are used to connect
cable conductors to other cable
conductors or electrical devices.
Connections associated with cables
within the scope of license renewal are
part of this program. The most common
types of connections used in nuclear
power plants are splices (butt or bolted),
crimp-type ring lugs, connectors, and
terminal blocks. Most connections
involve insulating material and metallic
parts. This aging management program
(AMP) focuses on the metallic parts of
the electrical cable connections. This
program provides a one-time inspection,
on a sampling basis, to confirm the
absence of age-related degradation of
cable connections due to thermal
cycling, ohmic heating, electrical
transients, vibration, chemical
contamination, corrosion, and
oxidation.
Generic Aging Lesson Learned (GALL)
XI.E1, ‘‘Electrical Cables and
Connections Not Subject to 10 CFR
50.49 Environmental Qualification
Requirements,’’ manages the aging of
insulating material but not the metallic
parts of the electrical connections.
GALL XI.E1 is based on only a visual
inspection of accessible cables and
connections. Visual inspection may not
be sufficient to detect the aging effects
from thermal cycling, ohmic heating,
electrical transients, vibration, chemical
contamination, corrosion, and oxidation
on the metallic parts of cable
connections.
Electrical cable connections exposed
to appreciable ohmic or ambient heating
during operation may experience
loosening caused by repeated cycling of
connected loads or of the ambient
temperature environment. Different
materials used in various cable system
components can produce situations
where stresses between these
components change with repeated
thermal cycling. For example, under
loaded conditions, ohmic heating may
raise the temperature of a compression
terminal and cable conductor well
above the ambient temperature, thereby
causing thermal expansion of both
components. Thermal expansion
coefficients of different materials may
alter mechanical stresses between the
components so that the termination may
be impacted. When the current is
reduced, the affected components cool
and contract. Repeated cycling in this
fashion can cause loosening of the
termination, and may lead to high
VerDate Aug<31>2005
18:25 Sep 05, 2007
Jkt 211001
electrical resistance or eventual
separation of compression-type
terminations. Threaded connectors may
loosen if subjected to significant
thermally induced stress and cycling.
Cable connections within the scope of
license renewal should be tested at least
once prior to the period of extended
operation to provide an indication of the
integrity of the cable connections. The
specific type of test to be performed and
is to be a proven test for detecting loose
connections, such as thermography,
contact resistance testing, or another
appropriate test justified in the
application.
This program, as described, can be
thought of as a sampling program. The
following factors shall be considered for
sampling: voltage level (medium and
low voltage), circuit loading (high
loading), and location (high
temperature, high humidity, vibration,
etc.). The technical basis for the sample
selections should be documented. If an
unacceptable condition or situation is
identified in the selected sample,
corrective action program will be used
to evaluate the condition and determine
appropriate corrective action.
SAND 96–0344, ‘‘Aging Management
Guidelines for Electrical Cable and
Terminations,’’ indicated loose
terminations were identified by several
plants. The major concern is that the
failures of a deteriorated cable system
(cables, connections including fuse
holders, and penetrations) that could
prevent it from performing its intended
function. This program is not applicable
to cable connections in harsh
environments since they are already
addressed by the requirements of 10
CFR 50.49. Even though cable
connections may not be exposed to
harsh environments, loosening or high
resistance of connection is a concern
due to aging mechanisms discussed
above.
Evaluation and Technical Basis
1. Scope of Program: External
connections terminating at an active or
passive device are in the scope of this
program. Wiring connections internal to
an active assembly are considered a part
of the active assembly and therefore are
not within the scope of this program.
This program does not include highvoltage (>35 kV) switchyard
connections. The cable connections
covered under the EQ program are not
included in the scope of this program.
2. Preventive Actions: No actions are
taken as part of this program to prevent
or mitigate aging degradation.
3. Parameters Monitored/Inspected:
This program will focus on the metallic
parts of the connection. The monitoring
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Fmt 4703
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includes loosening of bolted
connections or high resistance of cable
connections due to thermal cycling,
ohmic heating, electrical transients,
vibration, chemical contamination,
corrosion, and oxidation. A
representative sample of electrical cable
connections is tested. The following
factors shall be considered for sampling:
voltage level (medium and low voltage),
circuit loading (high load), and location
(high temperature, high humidity,
vibration, etc.). The technical basis for
the sample selection is to be
documented.
4. Detection of Aging Effects: A
representative sample of electrical
connections within the scope of license
renewal will be tested at least once prior
to the period of extended operation to
confirm that there are no aging effects
requiring management during the period
of extended operation. Testing may
include thermography, contact
resistance testing, or other appropriate
testing methods without removing the
connection insulation such as heat
shrink tape, sleeving, insulating boots,
etc. The one-time inspection provides
additional confirmation to support
industry operating experience that
shows electrical connections have not
experienced a high degree of failures,
and that existing installation and
maintenance practices are effective.
5. Monitoring and Trending: Trending
actions are not included as part of this
program because it is a one-time
inspection program.
6. Acceptance Criteria: The
acceptance criteria for each test are to be
defined for the specific type of test
performed and the specific type of cable
connections tested.
7. Corrective Actions: If test
acceptance criteria are not met, the
corrective action program will be used
to perform an evaluation that will
consider the extent of the condition, the
indications of aging effect, and changes
to the one-time inspection program.
Corrective actions may include, but are
not limited to sample expansion,
increase inspection frequency, and
replacement or repair of the affected
cable connection components. As
discussed in the appendix to this report,
the staff finds the requirements of 10
CFR Part 50, Appendix B, acceptable to
address the corrective actions.
8. Confirmation Process: As discussed
in the appendix to this report, the staff
finds the requirements of 10 CFR Part
50, Appendix B, acceptable to address
the confirmation process.
9. Administrative Controls: As
discussed in the appendix to this report,
the staff finds the requirements of 10
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Federal Register / Vol. 72, No. 172 / Thursday, September 6, 2007 / Notices
CFR Part 50, Appendix B, acceptable to
address the administrative controls.
10. Operating Experience: Electrical
cable connections exposed to
appreciable ohmic or ambient heating
during operation may experience
loosening caused by repeated cycling of
connected loads or of the ambient
temperature environment. There have
been limited number of age related
failures of cable connections reported.
This one-time inspection confirms the
absence of aging degradation of metallic
cable connections.
References
EPRI TR–109619, Guideline for the
Management of Adverse Localized
Equipment Environments, Electric Power
Research Institute, Palo Alto, CA, June
1999.
IEEE Std. P1205–2000, IEEE Guide for
Assessing, Monitoring and Mitigating
Aging Effects on Class 1E Equipment
Used in Nuclear Power Generating
Stations.
NUREG/CR–5643, Insights Gained From
Aging Research, U.S. Nuclear Regulatory
Commission, March 1992.
SAND96–0344, Aging Management
Guideline for Commercial Nuclear Power
Plants—Electrical Cable and
Terminations, prepared by Sandia
National Laboratories for the U.S.
Department of Energy, September 1996.
EPRI TR–104213, Bolted Joint Maintenance &
Application Guide, Electric Power
Research Institute, Palo Alto, CA,
December 1995.
Staff’s Response to the NEI White Paper on
Generic Aging Lessons Learned (GALL)
Report Aging Management Program
(AMP) XI.E6, ‘‘Electrical Cable
Connections Not Subject to 10 CFR 50.49
Environmental Qualification
Requirements,’’ dated March 16, 2007
(ADAMS Accession Number
ML070400349)
[FR Doc. E7–17616 Filed 9–5–07; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
Notice of Availability of Model
Application Concerning Technical
Specification Improvement To Revise
Moderator Temperature Coefficient
(MTC) Surveillance for Startup Test
Activity Reduction (STAR) Program
(WCAP–16011)
Nuclear Regulatory
Commission.
ACTION: Notice of Availability.
mstockstill on PROD1PC66 with NOTICES
AGENCY:
SUMMARY: Notice is hereby given that
the staff of the Nuclear Regulatory
Commission (NRC) has prepared a
model safety evaluation (SE) and model
license amendment request (LAR)
relating to the modification of technical
VerDate Aug<31>2005
18:25 Sep 05, 2007
Jkt 211001
specification (TS) moderator
temperature coefficient (MTC)
surveillance requirements (SR)
associated with implementation of
WCAP–16011–P–A, ‘‘Startup Test
Activity Reduction (STAR) Program.’’
The NRC staff has also prepared a model
no significant hazards consideration
(NSHC) determination relating to this
matter. The purpose of these models are
to permit the NRC to efficiently process
amendments that propose to modify TS
MTC surveillance requirements for
implementing the STAR Program.
Licensees of nuclear power reactors to
which the models apply could then
request amendments, confirming the
applicability of the SE and NSHC
determination to their reactors.
DATES: The NRC staff issued a Federal
Register notice (72 FR 41360, July 27,
2007) which provided a model SE,
model application, and model NSHC
related to modification of TS MTC
surveillance requirements. Similarly,
the NRC staff herein provides a revised
model SE, model LAR, and model
NSHC incorporating changes based
upon the public comments received.
The NRC staff can most efficiently
consider applications based upon the
model LAR, which references the model
SE, if the LAR is submitted within one
year of this Federal Register Notice.
FOR FURTHER INFORMATION CONTACT:
Timothy Kobetz, Mail Stop: O–12H2,
Technical Specifications Branch,
Division of Inspection & Regional
Support, Office of Nuclear Reactor
Regulation, U.S. Nuclear Regulatory
Commission, Washington, DC 20555–
0001, telephone 301–415–1932.
SUPPLEMENTARY INFORMATION:
Background
Regulatory Issue Summary 2000–06,
‘‘Consolidated Line Item Improvement
Process for Adopting Standard
Technical Specification Changes for
Power Reactors,’’ was issued on March
20, 2000. The consolidated line item
improvement process (CLIIP) is
intended to improve the efficiency of
NRC licensing processes by processing
proposed changes to the standard
technical specifications (STS) in a
manner that supports subsequent
license amendment applications. The
CLIIP includes an opportunity for the
public to comment on proposed changes
to the STS following a preliminary
assessment by the NRC staff and finding
that the change will likely be offered for
adoption by licensees. The CLIIP directs
the NRC staff to evaluate any comments
received for a proposed change to the
STS and to either reconsider the change
or to proceed with announcing the
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51259
availability of the change for proposed
adoption by licensees. Those licensees
opting to apply for the subject change to
technical specifications are responsible
for reviewing the staff’s evaluation,
referencing the applicable technical
justifications, and providing any
necessary plant-specific information.
Each amendment application made in
response to the notice of availability
will be processed and noticed in
accordance with applicable rules and
NRC procedures.
This notice involves the modification
of TS MTC surveillance requirements
for implementing the STAR Program.
This change was proposed for
incorporation into the standard
technical specifications by the owners
groups participants in the Technical
Specification Task Force (TSTF) and is
designated TSTF–486, Revision 2.
TSTF–486, Revision 2, can be viewed
on the NRC’s Web page at https://
www.nrc.gov/reactors/operating/
licensing/techspecs.html.
Applicability
This proposal to modify TS MTC
surveillance requirements for
implementing the STAR Program, as
proposed in TSTF–486, Revision 2, is
applicable to Combustion Engineering
(CE) design plants.
To efficiently process the incoming
license amendment applications, the
staff requests that each licensee
applying for the changes proposed in
TSTF–486, Revision 2, include TS Bases
for the proposed TS consistent with the
TS Bases proposed in TSTF–486,
Revision 2. The staff is requesting that
the TS Bases be included with the
proposed license amendments in this
case because the changes to the TS and
the changes to the associated TS Bases
form an integral change to a plant’s
licensing basis. To ensure that the
overall change, including the TS Bases,
includes appropriate regulatory
controls, the staff plans to condition the
issuance of each license amendment on
the licensee’s incorporation of the
changes into the TS Bases document
and that the licensee control changes to
the TS Bases in accordance with the
licensees TS Bases Control Program.
The CLIIP does not prevent licensees
from requesting an alternative approach
or proposing the changes without the
requested TS Bases. However,
deviations from the approach
recommended in this notice may require
additional review by the NRC staff and
may increase the time and resources
needed for the review. Significant
variations from the approach, or
inclusion of additional changes to the
license, will result in staff rejection of
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Agencies
[Federal Register Volume 72, Number 172 (Thursday, September 6, 2007)]
[Notices]
[Pages 51256-51259]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-17616]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
Proposed License Renewal Interim Staff Guidance LR-ISG-2007-02:
Changes to Generic Aging Lesson Learned (GALL) Report Aging Management
Program (AMP) XI.E6, ``Electrical Cable Connections Not Subject to 10
CFR 50.49 Environmental Qualification Requirements'' Solicitation of
Public Comment
AGENCY: U.S. Nuclear Regulatory Commission.
ACTION: Solicitation of public comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is soliciting
public comment on its Proposed License Renewal Interim Staff Guidance
LR-ISG-2007-02 (LR-ISG) for changes to its Generic Aging Lesson Learned
(GALL) Report Aging Management Program (AMP) XI.E6, ``Electrical Cable
Connections Not Subject to 10 CFR 50.49 Environmental Qualification
Requirements.'' This LR-ISG clarifies and recommends a one-time
inspection to ensure that either aging of metallic cable connections is
not occurring or an existing preventive maintenance program is
effective, such that a periodic inspection is not needed. The NRC staff
issues LR-ISGs to facilitate timely implementation of the license
renewal rule and to review activities associated with an LRA. Upon
receiving public comments, the NRC staff will evaluate the comments and
make a determination to incorporate the comments, as appropriate. Once
the NRC staff completes the LR-ISG, it will issue the LR-ISG for NRC
and industry use. The NRC staff will also incorporate the approved LR-
ISG into the next revision of the license renewal guidance documents.
DATES: Comments may be submitted by October 22, 2007. Comments received
after this date will be considered, if it is practical to do so, but
the Commission is able to ensure consideration only for comments
received on or before this date.
ADDRESSES: Comments may be submitted to: Chief, Rulemaking, Directives,
and Editing Branch, Office of Administration, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001. Comments should be delivered to:
11545 Rockville Pike, Rockville, Maryland, Room T-6D59, between 7:30
a.m. and 4:15 p.m. on Federal workdays. Persons may also provide
comments via e-mail at NRCREP@NRC.GOV. The NRC maintains an Agencywide
Documents Access and Management System (ADAMS), which provides text and
image files of NRC's public documents. These documents may be accessed
through the NRC's Public Electronic Reading Room on the Internet at
http: //www.nrc.gov/reading-rm/adams.html. Persons who do not have
access to ADAMS or who encounter problems in accessing the documents
located in ADAMS should contact the NRC Public Document Room (PDR)
reference staff at 1-800-397-4209, 301-415-4737, or by e-mail at
pdr@nrc.gov.
FOR FURTHER INFORMATION CONTACT: Ms. Linh Tran, Project Manager, Office
of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001; telephone 301-415-4103 or by e-mail at
Int@nrc.gov.
SUPPLEMENTARY INFORMATION: Attachment 1 to this Federal Register
notice, entitled Staff Position and Rationale for the Proposed License
Renewal Interim Staff Guidance LR-ISG-2007-02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging Management Program (AMP) XI.E6,
``Electrical Cable Connections Not Subject to 10 CFR 50.49
Environmental Qualification Requirements,'' contains the NRC staff's
rationale for publishing the proposed LR-ISG-2007-02. Attachment 2 to
this Federal Register notice, entitled Proposed License Renewal Interim
Staff Guidance LR-ISG-2007-02: Changes to Generic Aging Lesson Learned
(GALL) Report Aging Management Program (AMP) XI.E6, ``Electrical Cable
Connections Not Subject to 10 CFR 50.49 Environmental Qualification
Requirements,'' contains the proposed revisions to GALL AMP XI.E6.
The NRC staff is issuing this notice to solicit public comments on
the proposed LR-ISG-2007-02. After the NRC staff considers any public
comments, it will make a determination regarding issuance of the
proposed LR-ISG.
Dated at Rockville, Maryland this 29th day of August, 2007.
For the Nuclear Regulatory Commission.
Pao-Tsin Kuo,
Director, Division of License Renewal, Office of Nuclear Reactor
Regulation.
Attachment 1--Staff Position and Rationale for the Proposed License
Renewal Interim Staff Guidance LR-ISG-2007-02: Changes to Generic Aging
Lesson Learned (GALL) Report Aging Management Program (AMP) XI.E6,
``Electrical Cable Connections Not Subject to 10 CFR 50.49
Environmental Qualification Requirements''
Staff Position
The staff is proposing to revise GALL AMP XI.E6 to recommend a one-
time inspection for electrical cable connections not subject to 10 CFR
50.49 environmental qualification requirement instead of the period
inspection as currently stated in GALL AMP XI.E6. The staff determined
that this one-time inspection, on representative sample basis, is
adequate to ensure that either aging of metallic cable connections is
not occurring and/or existing preventive maintenance program is
effective such that a periodic inspection program is not needed.
Rationale
In reviewing the industry's documents and comments, the staff
determined that although the current GALL AMP XI.E6 was based on
technical bases of Electric Power Research Institute documents, Sandia
National Laboratories Report, SAND 96-0344, and thermography data, few
operating experiences related to failed connection due to aging had
been identified. Most of the operating experience related to failed
connection are due to human errors or maintenance practices. The
operating experience cannot support a periodic inspection as currently
recommended in GALL AMP XI.E6. However, because there have been a
limited number of age related failures of cable connections, a one-time
inspection of the metallic portion of electrical cable connections is
warranted. On this basis, the staff is revising GALL AMP XI.E6 to
clarify and recommend a one-time inspection, on a representative
sampling basis, to ensure that either aging of metallic cable
connections is not occurring or an existing preventive maintenance
program is effective, such that a periodic inspection is not needed.
[[Page 51257]]
Attachment 2--Proposed License Renewal Interim Staff Guidance LR-ISG-
2007-02: Changes to Generic Aging Lesson Learned (GALL) Report Aging
Management Program (AMP) XI.E6, ``Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental Qualification Requirements''
Introduction
Consistent with the requirements specified in Title 10 of the Code
of Federal Regulations (10 CFR) Part 54, Section 54.4(a), electrical
cable connections support safety-related and non-safety-related
functions in that the failure of the electrical cable connections
precludes a function from being accomplished (10 CFR 54.4(a)(1),
(a)(2), and (a)(3)).
Electrical cable connections exposed to appreciable ohmic or
ambient heating during operation may experience loosening caused by
repeated cycling of connected loads or of the ambient temperature
environment. Different materials used in various cable system
components can produce situations where stresses between these
components change with repeated thermal cycling. For example, under
loaded conditions, ohmic heating may raise the temperature of a
compression terminal and cable conductor well above the ambient
temperature, thereby causing thermal expansion of both components.
Thermal expansion coefficients of different materials may alter
mechanical stresses between the components so that the termination may
be impacted. When the current is reduced, the affected components cool
and contract. Repeated cycling in this fashion can cause loosening of
the termination, and may lead to high electrical resistance or eventual
separation of compression-type terminations. Threaded connectors may
loosen if subjected to significant thermally induced stress and
cycling. Because of the potential loosening of bolted cable
connections, the staff included, in its updated license renewal
guidance documents, AMP XI.E6, ``Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental Qualification Requirements,'' to
manage the potential aging of electrical cable connections not subject
to 10 CFR 50.49 environmental qualification requirements.
Background and Discussion
The staff included AMP XI.E6, ``Electrical Cable Connections Not
Subject to 10 CFR 50.49 Environmental Qualification Requirements,'' in
Chapter XI of GALL Report, Revision 1, dated September 2005. By letter
dated September 5, 2006, (Agencywide Documents Access and Management
System (ADAMS) Accession No. ML062770105), Nuclear Energy Institute
(NEI) submitted a white paper regarding GALL AMP XI.E6 (ADAMS Accession
No. ML062770111) . NEI stated that there was not enough operating
experience to support a conclusion that cable connections are a
significant aging concern and that the recommended program elements of
GALL AMP XI.E6 duplicate aging management activities already defined
and accepted in other AMPs. NEI also stated that the expanded scope of
the program includes all voltage ranges regardless of the amount of
evidence from operating experience. In addition, NEI identified wording
in GALL AMP XI.E6 that included connections in active components. NEI
asked the staff to review its white paper to eliminate GALL AMP XI.E6
or minimize its scope and redundancy so that the plant would not be
burdened with activities that have no actual aging management benefit.
On November 30, 2006, the staff met with NEI representatives to
discuss the white paper. In a letter dated March 16, 2007, (ADAMS
Accession No. ML070400349), the staff provided responses to each of the
industry's concerns identified in the white paper. By letter dated May
25, 2007, (ADAMS Accession Nos. ML071590175 and ML071590182), NEI
submitted comments on the staff's responses.
In reviewing the industry's white paper and comments, the staff
determined that although GALL AMP XI.E6 was based on the technical
bases of Electric Power Research Institute documents, and Sandia
National Laboratories Report, SAND 96-0344, little operating experience
related to failed connections due to aging had been identified. Most of
the operating experience related to failed connections were due to
human errors or maintenance practices. The operating experience cannot
support the periodic inspection recommended in AMP XI.E6 in GALL
Report, Revision 1, dated September 2005. However, because there have
been a limited number of age related failures of cable connections, a
one-time inspection of the metallic portion of electrical cable
connections is warranted. On this basis, the staff is revising GALL AMP
XI.E6 to clarify and recommend a one-time inspection, on a
representative sampling, to ensure that either aging of metallic cable
connections is not occurring or an existing preventive maintenance
program is effective, such that a periodic inspection is not required.
Proposed Action
The staff is proposing to revise GALL AMP XI.E6 to recommend a one-
time inspection prior to the period of extended operation for
electrical cable connections not subject to 10 CFR 50.49 EQ requirement
instead of the periodic inspection currently stated in GALL AMP XI.E6.
The staff determined that this one-time inspection, on a representative
sample basis, is adequate to ensure that either aging of metallic cable
connections is not occurring and/or the existing preventive maintenance
program is effective so that a periodic inspection program is not
required. The one-time inspection verifies that loosening and/or high
resistance of cable connections due to thermal cycling, ohmic heating,
electrical transients, vibration, chemical contamination, corrosion,
and oxidation are not happening and periodic inspections are not
required. The one-time inspection should include testing of a
representative sample of the electrical cable connection population
subject to an aging effect. The sample should include each type of
electrical cable connection. The following factors shall be considered
for sampling: voltage level (medium and low voltage), circuit loading
(high load), and location (high temperature, high humidity, vibration,
etc.). The technical basis for the sample selection should be
documented. The one-time inspection will confirm that there are no
aging effects that require management during the period of extended
operation.
The applicant will take corrective actions when acceptance criteria
are not met. Corrective actions may include, but are not limited to
sample expansion, increased inspection frequency, and replacement or
repair of the affected cable connection components.
When an applicant performs periodic preventive maintenance that
includes inspection and testing of cable connections, the applicant can
credit this maintenance activity toward GALL AMP XI.E6. The applicant
may also revise its preventive maintenance procedures to cover the
inspection of cable connections to take credit for GALL AMP XI.E6.
Attached is the proposed revision to GALL AMP XI.E6. Although this
proposed revision does not convey a change in the regulations or how
they are being interpreted, it is being provided to facilitate
preparation of future submittals in support of applications for license
renewal. This LR-ISG provides a clarification of existing guidance with
no additional requirements.
[[Page 51258]]
Attachment--XI.E6 Electrical Cable Connections Not Subject to 10 CFR
50.49 Environmental Qualification Requirements (Revised)
Program Description
Cable connections are used to connect cable conductors to other
cable conductors or electrical devices. Connections associated with
cables within the scope of license renewal are part of this program.
The most common types of connections used in nuclear power plants are
splices (butt or bolted), crimp-type ring lugs, connectors, and
terminal blocks. Most connections involve insulating material and
metallic parts. This aging management program (AMP) focuses on the
metallic parts of the electrical cable connections. This program
provides a one-time inspection, on a sampling basis, to confirm the
absence of age-related degradation of cable connections due to thermal
cycling, ohmic heating, electrical transients, vibration, chemical
contamination, corrosion, and oxidation.
Generic Aging Lesson Learned (GALL) XI.E1, ``Electrical Cables and
Connections Not Subject to 10 CFR 50.49 Environmental Qualification
Requirements,'' manages the aging of insulating material but not the
metallic parts of the electrical connections. GALL XI.E1 is based on
only a visual inspection of accessible cables and connections. Visual
inspection may not be sufficient to detect the aging effects from
thermal cycling, ohmic heating, electrical transients, vibration,
chemical contamination, corrosion, and oxidation on the metallic parts
of cable connections.
Electrical cable connections exposed to appreciable ohmic or
ambient heating during operation may experience loosening caused by
repeated cycling of connected loads or of the ambient temperature
environment. Different materials used in various cable system
components can produce situations where stresses between these
components change with repeated thermal cycling. For example, under
loaded conditions, ohmic heating may raise the temperature of a
compression terminal and cable conductor well above the ambient
temperature, thereby causing thermal expansion of both components.
Thermal expansion coefficients of different materials may alter
mechanical stresses between the components so that the termination may
be impacted. When the current is reduced, the affected components cool
and contract. Repeated cycling in this fashion can cause loosening of
the termination, and may lead to high electrical resistance or eventual
separation of compression-type terminations. Threaded connectors may
loosen if subjected to significant thermally induced stress and
cycling.
Cable connections within the scope of license renewal should be
tested at least once prior to the period of extended operation to
provide an indication of the integrity of the cable connections. The
specific type of test to be performed and is to be a proven test for
detecting loose connections, such as thermography, contact resistance
testing, or another appropriate test justified in the application.
This program, as described, can be thought of as a sampling
program. The following factors shall be considered for sampling:
voltage level (medium and low voltage), circuit loading (high loading),
and location (high temperature, high humidity, vibration, etc.). The
technical basis for the sample selections should be documented. If an
unacceptable condition or situation is identified in the selected
sample, corrective action program will be used to evaluate the
condition and determine appropriate corrective action.
SAND 96-0344, ``Aging Management Guidelines for Electrical Cable
and Terminations,'' indicated loose terminations were identified by
several plants. The major concern is that the failures of a
deteriorated cable system (cables, connections including fuse holders,
and penetrations) that could prevent it from performing its intended
function. This program is not applicable to cable connections in harsh
environments since they are already addressed by the requirements of 10
CFR 50.49. Even though cable connections may not be exposed to harsh
environments, loosening or high resistance of connection is a concern
due to aging mechanisms discussed above.
Evaluation and Technical Basis
1. Scope of Program: External connections terminating at an active
or passive device are in the scope of this program. Wiring connections
internal to an active assembly are considered a part of the active
assembly and therefore are not within the scope of this program. This
program does not include high-voltage (>35 kV) switchyard connections.
The cable connections covered under the EQ program are not included in
the scope of this program.
2. Preventive Actions: No actions are taken as part of this program
to prevent or mitigate aging degradation.
3. Parameters Monitored/Inspected: This program will focus on the
metallic parts of the connection. The monitoring includes loosening of
bolted connections or high resistance of cable connections due to
thermal cycling, ohmic heating, electrical transients, vibration,
chemical contamination, corrosion, and oxidation. A representative
sample of electrical cable connections is tested. The following factors
shall be considered for sampling: voltage level (medium and low
voltage), circuit loading (high load), and location (high temperature,
high humidity, vibration, etc.). The technical basis for the sample
selection is to be documented.
4. Detection of Aging Effects: A representative sample of
electrical connections within the scope of license renewal will be
tested at least once prior to the period of extended operation to
confirm that there are no aging effects requiring management during the
period of extended operation. Testing may include thermography, contact
resistance testing, or other appropriate testing methods without
removing the connection insulation such as heat shrink tape, sleeving,
insulating boots, etc. The one-time inspection provides additional
confirmation to support industry operating experience that shows
electrical connections have not experienced a high degree of failures,
and that existing installation and maintenance practices are effective.
5. Monitoring and Trending: Trending actions are not included as
part of this program because it is a one-time inspection program.
6. Acceptance Criteria: The acceptance criteria for each test are
to be defined for the specific type of test performed and the specific
type of cable connections tested.
7. Corrective Actions: If test acceptance criteria are not met, the
corrective action program will be used to perform an evaluation that
will consider the extent of the condition, the indications of aging
effect, and changes to the one-time inspection program. Corrective
actions may include, but are not limited to sample expansion, increase
inspection frequency, and replacement or repair of the affected cable
connection components. As discussed in the appendix to this report, the
staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable
to address the corrective actions.
8. Confirmation Process: As discussed in the appendix to this
report, the staff finds the requirements of 10 CFR Part 50, Appendix B,
acceptable to address the confirmation process.
9. Administrative Controls: As discussed in the appendix to this
report, the staff finds the requirements of 10
[[Page 51259]]
CFR Part 50, Appendix B, acceptable to address the administrative
controls.
10. Operating Experience: Electrical cable connections exposed to
appreciable ohmic or ambient heating during operation may experience
loosening caused by repeated cycling of connected loads or of the
ambient temperature environment. There have been limited number of age
related failures of cable connections reported. This one-time
inspection confirms the absence of aging degradation of metallic cable
connections.
References
EPRI TR-109619, Guideline for the Management of Adverse Localized
Equipment Environments, Electric Power Research Institute, Palo
Alto, CA, June 1999.
IEEE Std. P1205-2000, IEEE Guide for Assessing, Monitoring and
Mitigating Aging Effects on Class 1E Equipment Used in Nuclear Power
Generating Stations.
NUREG/CR-5643, Insights Gained From Aging Research, U.S. Nuclear
Regulatory Commission, March 1992.
SAND96-0344, Aging Management Guideline for Commercial Nuclear Power
Plants--Electrical Cable and Terminations, prepared by Sandia
National Laboratories for the U.S. Department of Energy, September
1996.
EPRI TR-104213, Bolted Joint Maintenance & Application Guide,
Electric Power Research Institute, Palo Alto, CA, December 1995.
Staff's Response to the NEI White Paper on Generic Aging Lessons
Learned (GALL) Report Aging Management Program (AMP) XI.E6,
``Electrical Cable Connections Not Subject to 10 CFR 50.49
Environmental Qualification Requirements,'' dated March 16, 2007
(ADAMS Accession Number ML070400349)
[FR Doc. E7-17616 Filed 9-5-07; 8:45 am]
BILLING CODE 7590-01-P