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]

Download as PDF 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 VerDate Aug<31>2005 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. PO 00000 Frm 00045 Fmt 4703 Sfmt 4703 E:\FR\FM\06SEN1.SGM 06SEN1 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 VerDate Aug<31>2005 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. PO 00000 Frm 00046 Fmt 4703 Sfmt 4703 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. E:\FR\FM\06SEN1.SGM 06SEN1 51258 Federal Register / Vol. 72, No. 172 / Thursday, September 6, 2007 / Notices mstockstill on PROD1PC66 with NOTICES 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 PO 00000 Frm 00047 Fmt 4703 Sfmt 4703 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 E:\FR\FM\06SEN1.SGM 06SEN1 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 PO 00000 Frm 00048 Fmt 4703 Sfmt 4703 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 http:// 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 E:\FR\FM\06SEN1.SGM 06SEN1

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]


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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.

-----------------------------------------------------------------------

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