ML993350424
| ML993350424 | |
| Person / Time | |
|---|---|
| Site: | PROJ0690 |
| Issue date: | 11/18/1999 |
| From: | Charemagne Grimes NRC/NRR/DRIP/RLSB |
| To: | Walters D Nuclear Energy Institute |
| References | |
| -nr | |
| Download: ML993350424 (68) | |
Text
November 18, 1999 Mr. Douglas J. Walters Nuclear Energy Institute 1776 1 Street, NW., Suite 400 Washington, DC 20006-3708
SUBJECT:
DRAFT GENERIC AGING LESSONS LEARNED (GALL) REPORT:
CHAPTER VI, ELECTRICAL COMPONENTS
Dear Mr. Walters:
As discussed in our meeting on October 15, 1999, the staff is releasing portions of the draft Generic Aging Lessons Learned (GALL) report to invite early stakeholders participation in developing license renewal implementation guidance documents. Accordingly, we have enclosed Chapter VI, "Electrical Components," of the draft GALL report for your information and comment.
We plan to have a first draft of the GALL report available at our public workshop on December 6, 1999. If you have any questions, please contact Sam Lee at (301)415-3109.
Sincerely, Christopher I. Grimes, Chief License Renewal and Standardization Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Project No. 690
Enclosure:
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NUCLEAR ENERGY INSTITUTE (License Renewal Steering Committee)
Project No. 690 cc:
Mr. Dennis Harrison U.S. Department of Energy NE-42 Washington, D.C. 20585 Mr. Ricard P. Sedano, Commissioner State Liaison Officer Department of Public Service 112 State Street Drawer 20 Montipelier, Vermont 05620-2601 Mr. Douglas J. Walteje Nuclear Energy I tute 1776 IStreet Washingtn, DC 20006 DJ NEI.ORG National Whistleblower Center 3233 P Street, N.W.
Washington, DC 20007 Mr. Garry Young Entergy Operations, Inc.
Arkansas Nuclear One 1448 SR 333 GSB-2E Russellville, Arkansas 72802 Mr. James P. Riccio Public Citizen's Critical Mass Energy Project 211 Pennsylvania Avenue, SE Washington, DC 20003 Mr. Robert Gill Duke Energy Corporation Mail Stop EC-12R P.O. Box 1006 Charlotte, NC 28201-1006 Mr. Charles R. Pierce Southern Nuclear Operating Co.
40 Inverness Center Parkway BIN 8064 Birmingham, AL 35242 Carl J. Yoder Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway NEF 1st Floor Lusby, Maryland 20657 Chattooga River Watershed Coalition P. O. Box 2006 Clayton, GA 30525 Mr. David Lochbaum Union of Concerned Scientists 1616 P. St., NW Suite 310 Washington, DC 20036-1495 Mr. Paul Gunter Director of the Reactor Watchdog Project Nuclear Information & Resource Service 1424 16th Street, NW, Suite 404 Washington, DC 20036
DRAFT GENERIC AGING LESSONS LEARNED (GALL) REPORT Draft-November 12, 1999
CHAPTER VI ELECTRICAL COMPONENTS Draft November 12, 1999
Major Electrical Components A.
Electric Cables B.
Electrical Connectors C.
Electrical Penetration Assemblies D.
Electrical Buses E.
Electrical Insulators F.
Transmission Conductors G.
Ground Conductors Draft November 12, 1999
A.
Electric Cables A. 1 Power, Instrumentation and Control Cables A. 1.1 Conductor A.1.2 Shield Wire A.1.3 Insulation A.1.4 Jacket VI A-I Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Systems, Structures and Components This review table addresses electric cables, including power, instrumentation and control (I&C) cables. The power cables addressed are low-voltage (< 1000 V) and medium voltage (2 kV to 15 kV), which have similar constructions to I&C cables. High voltage power cables (>15 kV) have unique, specialized construction and must be evaluated on an application specific basis. Since the cable types addressed herein are very similar in construction and aging effects, they are grouped together in the table. Individual sub-components for a typical cable are addressed in terms-of aging mechanisms and effects.
System Interfaces Electric cables functionally interface with all plant systems that rely on electric power and/or instrumentation and control. Physical interfaces include routing in cable trays and conduits.
VI A-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References A. 1.1
- Power, Conductor Copper Humid, "
Increased Corrosion IE Bulletin 79-lB Control, &
- coated or Chemical circuit (DOR Guideline)
Instrument non-coated Exposure resistance, Cables
- stranded or
- heating, NUREG-0588 solid signal noise, circuit failure IEEE Standards
- 323-1971
- 323-1974
- 383-1974
- 317-1976
- 338-1987
- 1205-1993 Regulatory Guide 1.89, Rev. 1 IOCFR50.49 EQ Rule VI A-3 Draft November 12, 1999
Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation A. Environmentally Qualified Equipment For electrical equipment that is environmentally qualified for use in nuclear power plants, the environmental qualification program may be applicable as a tool for aging management.
Environmental Qualification (10CFR50.49:
EQ Rule)
EQ requirements have evolved over the years; therefore, plants of various vintages are licensed based on different EQ requirements.
There are three main documents that chronicle the EQ requirements, starting with the IE Bulletin 79-OIB (DOR guidelines) issued in 1979. This was followed by NUREG-0588, which specifies two categories of qualifications, and finally the current EQ Rule (10 CFR 50.49). The DOR Guidelines and NUREG-0588 Category II are consistent with the original IEEE Standard for qualifying Class lE equipment (IEEE Std 323-1971), while NUREG-0588 Category I and 10 CFR 50.49 endorse a later version of the standard (IEEE Std 323-1974). IEEE Standard 323-1974 includes more stringent requirements than the 1971 version, including the application of margins to test parameters and pre-aging of equipment prior to accident testing. It should be noted that the NRC has not endorsed a later version of the standard (IEEE Std 323-1983).
While many of the older vintage plants were licensed based on the DOR Guidelines[NUREG-0588, Category II, many of the electric cables inside containment (over 70%) included pre-aging as part of their original qualification, or have been re qualified to Category I criteria.
Many older plants still utilize cable connections and electrical penetrations that were environmentally qualified in accordance with the DOR Guidelines and/or the NUREG 0588, Category II requirements. The original qualification of many of these components might not have included pre-aging prior to exposing them to accident conditions.
A. Environmentally Qualified Eauiwment II I
m m
AIl.
Environme Qualified Equipment Yes.
In the case where the TLAA is projected to the end of the period of extended operation, the analysis attributes identified should be addressed Draft November 12, 1999 VI. ELECTRICAL COMPONENTS A. Electric Cables VI A-4 A Environmentally Qualified Eauipment In general, the EQ process accounts for aging through the use of a Time Limited Aging Analysis (TLAA) for the equipment to be qualified. It does not require the use of prevention or mitigation measures, or the use of condition/performance monitoring.
Therefore, EQ cannot be considered a typical aging management program. However, the TLAA does provide some assurance that the effects of aging will not be problematic during the qualified life of the equipment. As such, EQ can be considered part of an aging management program for license renewal if the licensee can show i) the TLAA remains valid for the period of extended operation, ii) the TLAA is projected to the end of the period of extended operation through re-analysis, or iii) the effects of aging on the intended function(s) will be adequately managed during the period of extended operation.
For case (i), the existing qualification is acceptable for extended life and no further evaluation is necessary.
For case (ii), a re-analysis is necessary to extend the qualified life of the equipment. In the re-analysis, attributes that should be addressed include analytical methods, data collection and reduction methods, underlying assumptions, acceptance criteria, corrective actions if acceptance criteria are not met, and the period of time prior to the end of qualified life when the re-analyses will be completed In light of case (iii), the EQ process was evaluated as an aging management program based on the 10 criteria identified in the draft SRP-LR. The following summarize this evaluation:
(1) Scope of Program: The EQ requirements apply to electric equipment important to safety, which includes those electrical components within the scope of license renewal (i.e., cables, connectors, and penetration assemblies). (2) Preventive Actions:
EQ does not require the use of preventive actions to manage the effects of aging. Aging is addressed through the use of a TLAA.
As such, the EQ process identifies no preventive actions. (3)
Parameter Monitored/Inspected: EQ is not a condition or performance monitoring program. As such, it does not identify any parameters to be monitored to manage the effects of aging.
Aging is addressed through the use of a TLAA. (4) Detection of Aging Effects: In general, EQ does not require the detection of aging effects for equipment while in service. When the qualified life is less than the current plant license period, EQ requires a program to replace or refurbish the component at the end of its qualified life. (5) Monitoring and Trending: EQ does not rely on monitoring and trending of condition or performance parameters of equipment while in service to manage the effects of aging. As such, no monitoring or trending activities for assessing
VI. ELECTRICAL COMPONENTS A. Electric Cables Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References I
L __________
.1 _________________
VI A-5 Draft November 12, 1999
Existing Aging Management Program (AMP)
Evaluation and Technical Basis E)
Another EPRI study on low-voltage environmentally qualified cables presented in an industry report (EPRI TR-103841, 6/94) analyzed Licensee Event Reports for the period from 1968 to June 1992. Only 87 LERs related to cables were considered attributable to aging and the failures were categorized as follows: thermal degradation (13 reports), mechanical damage (23 reports),
misapplication (I I reports), and unknown (40 reports). Roughly half of these failures occurred in the first 6 years of operation, and the number of failures decreased significantly after 10 years of operation.
VI A-6 Further valuation Draft November 12, 1999 VI. ELECTRICAL COMPONENTS A. Electric Cables the impact on equipment condition due to aging are identified by the EQ process. It should also be noted that currently, there are no recognized in situ condition monitoring methods that are effective for monitoring the condition of electric cables. Research is ongoing to determine if acceptable methods exist. (6) Acceptance Criteria: EQ does not rely on monitoring and trending of condition or performance parameters to manage the effects of aging. As such, no acceptance criteria are established for equipment operation while in service. (7) Corrective Actions: As part of the EQ process, a qualified life is established for the equipment being qualified. Once the equipment reaches the end of its qualified life, the only acceptable corrective action is refurbishment or replacement. (8 & 9) Confirmation process andAdministrative Controls: EQ does not rely on preventive or corrective actions to address the effects of aging. As such, the EQ process identifies no confirmation process. EQ documentation for each qualified component is maintained at the plant site in an auditable form for the duration of the installed life of the equipment. (10) Operating Experience: Passive electrical components are typically reliable devices under normal plant conditions and have very little evidence of significant failures. In a study performed by Sandia (SAND96 0344, 9/96), a database of nuclear plant component failure records was reviewed to identify relative number of failures, as well as typical failure modes and causes for electrical cables and terminations. The review covered data for the time period from 1975 to 1994, and generated 1,458 reports applicable to low and medium voltage cables and terminations. An analysis of these records showed the following:
- In general, these components have good reliability. However, aging degradation does occur and has led to failures.
- For low-voltage components, connectors accounted for the highest percentage of failures (30%). Cables (14.5%), terminal blocks (3.5%) and splices (2.5%) had relatively fewer failures.
- For medium voltage components cables had the highest percentage of failures (69%), followed by connectors (11%) and splices (17%).
- Most of the failures are detected by operation of the component; relatively few are detected by maintenance or surveillance.
VI.
ELECTRICAL COMPONENTS A. Electric Cables Structureand Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References I _________
.1 ___________
.1 _________
1 _______________
VI A-7 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing Further Aging anagement Program (AMP)
Evaluation and Technical Basis Evaluation Presently, GSI-168 is an open generic issue related to license renewal, and research is ongoing to provide information to resolve it. Specific issues being addressed in this research are presented in VI A-8 Draft November 12, 1999 NRC's aging assessment on cables, connections, and electrical penetration assemblies analyzed LER/NPE data for the period from mid-1980,to 1988 (NUREG/CR-5461, 6/90). An analysis of these failure data showed the following:
"* Out of 151 reported events on cables, more than 70% involved some type of electrical failure, either shorting, open circuit, or grounding faults.
"* Out of 196 reported events on connections, almost 80%
involved shorted, grounded, loose, or open connections.
"* Out of 39 reported events on EPAs, pressure leakage (41%) and electrical failure (26%) caused the most events.
Based on the results presented by these studies, it is seen that qualified electrical equipment does have good reliability, and aging degradation is usually well managed. These components receive little or no preventative maintenance. Under accident conditions, however, the reliability of these components is relatively unknown.
Many of the causes of failures in accident conditions would not be detected during normal operation because of the absence of high temperatures and humidity. Note that not all degradation is detected and mitigated before it results in failure. Therefore, additional aging management practices are needed to completely manage the effects of aging for these electrical components.
As discussed in SECY-93-049, during the staffs review of license renewal issues, the EQ process was found to be a significant issue.
Of particular concern was whether the EQ requirements for older plants (i.e., DOR guidelines, NUREG-0588 Cat. II), whose licensing bases differ from newer plants, are adequate for license renewal. Further, a question was raised as to whether the EQ requirements for older plants should be reassessed for the current licensing term. Upon subsequent review, additional concerns were raised related to the EQ process, and it was concluded that differences in EQ requirements constituted a potential generic issue that should be evaluated for backfit, independent of license renewal. This came to be identified as Generic Issue 168. Key items to be addressed in GSI-168 are:
"* The adequacy of older EQ requirements for license renewal, as well as for the current licensing term
"* The adequacy of accelerated aging techniques to simulate long-term natural service aging
"* The possibility that unique failure mechanisms exist for bonded jacket and multi-conductor cable configurations that are not adequately addressed in EQ
"* The feasibility of using condition monitoring (CM) techniques to monitor current cable condition in situ as a means of offsetting uncertainties in the process used to predict long term service aging
VI.
ELECTRICAL COMPONENTS A. Electric Cables Structure and Region of En Item Component Interest Material n
VI A-9 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation NUREG/CR-6384. Once this generic issue is resolved, guidance will be provided as to the impact on license renewal. In the interim, NRC letter dated June 2, 1998 "Guidance on Addressing GSI-168 for License Renewal," (C. Grimes, NRC to D. Walters, NEI) provides guidance on addressing GSI-168 in license renewal applications. It states that, until the generic issue is resolved, "....an acceptable approach described in the SOC is to provide a technical rationale demonstrating that the current licensing basis for EQ, pursuant to 10 CFR 50.49 will be maintained in the period of extended operation."
It should be noted that, currently, there are no acceptable non destructive CM techniques to measure the integrity of electric cables in situ. It does not appear that utilities can take credit for current functional testing of cables by periodic system or circuit testing as a means of satisfying the criteria for an item to be considered a replacement item. The effectiveness of several promising CM techniques for monitoring degradation of cables is the subject of an ongoing NRC research program. The results of this program will be part of the resolution of GSI-168.
B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment environme In many applications, electrical equipment The aging management programs discussed are generic in nature ntally may not be environmentally qualified, and and should be developed based on specific plant applications.
Qualified other aging management programs may be These programs will be evaluated on a plant specific basis.
Equipment applicable. The following are examples.
Yes.
Aging Inspection Program For those electrical components that are A plant accessible, a visual inspection can be used to specific provide some indication of aging degradation.
evaluation The visual inspection can check for surface is required.
anomalies, such as discoloration, cracking or surface contamination that would indicate the presence of active aging degradation. For cables, if the jacket or insulation can be touched, a qualitative indication of material hardening can be made. Observation of aging degradation would indicate the need for further investigation of the component.
Instrument Calibration Program Instrument calibration programs, including technical specification surveillance, may be used to provide an indirect indication of the condition of various electrical components. If calibration drift is noted for instruments, this could be an indication that aging degradation is affecting the electrical circuit. Further investigation could then be initiated to determine the nature of the degradation and the component affected.
VI A-10 Draft November 12, 1999
VI. ELECTRICAL COMPONENTS A. Electric Cables Structure and Item Component A. 1.2
- Power, Control, &
Instrument Cables A.I.3
- Power, Control, &
Instrument Cables Region of Interest Shield Wires Environ Material ment Braided
- Foil, Metallized mylar tape 1ulyli1*F5 such as XLPE, EPR, SR
- Humid, Chemical Exposure Aging Aging Effect Mechanism Signal noise or error in control and instrumnt.
cable Corroslon 1 ________
- rnumla, High voltage gradient (Power Cable)
Loss of dielectric
- strength, signal noise/
error, leakage current Moisture diffusion/
absorption; Formation of water trees in power cables Same as effect of corrosion on conductor for cables (A.1.1).
Same as effect of corrosion on conductor for cables (A. 1. 1).
I ________
I __________
I ________
j _____________
VI A-I1 Draft November 12, 1999
.It ii,* UlaLLUI l I
References
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing A in* Management Program (AMP)
Evaluation and Technical Basis A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.l).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. I.).
B. Non-environmentally Qualified A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. I).
Note:
The most probable location for shield wire corrosion is at exposed sites, such as terminations on equipment or terminal strips A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
B. Non-environmentally Qualified Equipment Equipment Same as effect of corrosion on conductor for cables (A.1.I).
environme Same as effect of corrosion on conductor for ntallY cables (A. 1.1)
Qualified Equipment Same as Note:
effect of Underwater cables or cables with prolonged exposure to humid corrosion environment, should be specifically designed for such applications, on conductor for cables (A.].1).
VI A-12 Draft November 12, 1999 i
Further Evaluation A.
Environme Qualified Equipment Same as effect of corrosion on conductor for cables (A.I.1).
B. Non environme nta!Ly Qualified Equipment Same as effect of corrosion on conductor for cables (A.].1).
A.
Environme ntA!LY Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
B. Non-
VI. ELECTRICAL COMPONENTS A. Electric Cables Item 1
c'.-------------T iLructure and Component Keglon o0 Interest Material Environ ment Aging Effect Efec Mechanism 1.
Aging Mechanism Control, &
Instrument Cables nIIIUKaonII rIolymers such as XLPE, EPR, SR High temp.,
Radiation,
- Oxygen, and Internal Ohmic heating (Power Cables)
Loss of dielectric
- strength, leakage
- current, signal noise/
error, circuit failure Hardening, Cracking Same as effect of corrosion on conductor for cables (A. 1.1).
I ________
I _______
I ______
+/- _______
I ______
I __
VI A-13 Draft November 12, 1999 A
1 2
I*....
J" Reference,
- LJ&e*
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing Aging Management Program (AMP)
A. Environmentallv Oualified Equipment Same as effect of corrosion on conductor for cables (A.1.I).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.]. 1).
Further Evaluation and Technical Basis Evaluation A. Environmentally Qualified Equipment A.
Same as effect of corrosion on conductor for cables (A. I.!).
Environme ntallv Qualified Equipment Same as effect of corrosion on conductor for cables (A.I.!).
Same as effect of corrosion on conductor for cables (A. 1. 1).
Note:
Some applications use different insulation materials, such as mineral insulation and polyimides (e.g., Kapton) which may be susceptible to different aging mechanisms.
Cracking can be initiated in a an embrittled cable by any movement of the cable, such as a seismic event, maintenance activities, or vibration from nearby operating equipment.
While embrittlement and cracking of cable insulation may not affect cable performance under normal, dry conditions, the aging effects noted would be probable when cables with cracks are exposed to moisture, such as in a design basis event. Moisture intrusion through the cracks could lead to shorting and possible circuit failure.
Draft November 12, 1999 B. Non environme ntalln Qualified Equipment Same as effect of corrosion on conductor for cables (A. I1-).
VI A-14 B. Non-environmentally Qualified Equipment T......................
lifi e Eqipm en
VI.
ELECTRICAL COMPONENTS A. Electric Cables Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References A. 1.4
- Power, Jacket Polymers High temp.,
Loss of Hardening, Same as effect of Control, &
such as Radiation, mechanical Cracking corrosion on Instrument
protection to underlying insulation.
Exposure of insulation to outside conditions.
VI A-15 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation A. Environmentally Oualitied Equipment Same as effect of corrosion on conductor for cables (Al.].).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductorfor cables (A.1.1).
Same as effect of corrosion on conductorfor cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductorfor cables (A. 1.1).
Note:
Jackets provide some degree of protection to underlying insulation from exposure to outside stressors, such as radiation, oxygen, moisture, dirt, dust and other contaminants.
For bonded jacket cables, in which the jacket is bonded to the insulation, cracking in the jacket has been found to propagate through to the insulation in some cases.
Environme otanly oualified Equipment Same as effect of corrosion on conductor for cables (A.1.JI).
B. Non environme ntal!Y qualified Equipment Same as effect of corrosion on conductor for cables (A.1.l).
Draft November 12, 1999 V1 A-16 A
M ined In I
m S...
ual.fie i[
ui I
e A. I*nvlronmenEallv QUallllCfl rtllllpilit;lil-
VI. ELECTRICAL COMPONENTS A. Electric Cables Structure and Item Component A. 1.4
- Power, Control, &
Instrument Cables Region of Interest Jacket Material Pfolymers such as
Radiation, Oxygen Aging Effect Loss of fire protection Aging Mechanism Loss of fire retardant References Same as effect of corrosion on conductor for cables (A. 1.1).
VI A-17 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS A. Electric Cables Existing Aging Management Program (AMP)
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
Further Evaluation and Technical Basis Evaluation A. Environmentally Qualified Equipment A.
Same as effect of corrosion on conductor for cables (A..1 ).
Environme ntallv Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.]).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A..1).
Note:
The primary purpose of the jacket is to protect the insulated conductors from fire and environmental stressors. No known condition monitoring method is available to determine the amount of fire retardant lost with the age of the jacket material.
Draft November 12, 1999 B. Non environme Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
VI A-18
VI.
ELECTRICAL COMPONENTS A. Electric Cables Structure and Region of En, Item Component Interest Material n
A. 1.4
- Power, Jacket Polymers Vibr; Control, &
such as main Instrument
VI. ELECTRICAL COMPONENTS A. Electric Cables Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation A. Environmentally Qualified Equipment A. Environmentally Qualified Equipment A.
Same as effect of corrosion on conductor for Same as effect of corrosion on conductor for cables (A. 1. 1).
Environme cables (A.]. 1).
_Qtally Qualified Equipment Same as effect of corrosion on conductor for cables (A.1).
B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
environme Same as effect of corrosion on conductor for ntally Qualified Note:
Equipment Wear due to vibration is most probable in locations where jacket is Same as adjacent to rough or sharp objects capable of causing cutting, effect of chafing or abrasion.
corrosion on Jackets provide some degree of protection to underlying insulation conductor from exposure to outside stressors, such as radiation, oxygen, for cables moisture, dirt, dust and other contaminants.
(A.1. 1).
VI A-20 Draft November 12, 1999
B.
Electrical Connectors B. 1 Splices B.1.1 Jackets B.1.2 Seals B.1.3 Insulators B.2 Mechanical Connectors B.2.1 Terminal Lugs, compression fittings, fusion connectors, contact pins B.3 Terminal Blocks B.3.1 Block Assembly VI R-1 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Systems, Structures and Components This review table addresses the electrical connectors that are used in electrical circuits to join the various components electrically. This includes splices, mechanical connectors and terminal blocks. Individual sub-components for each connector are addressed in terms of aging mechanisms and effects.
System Interfaces Electrical connectors are used in all electrical circuits, therefore, they functionally interface with all plant systems that rely on electric power and/or instrumentation and control. Physical interfaces include installation in junction boxes and various control panels.
VI B-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References D. L.1 OVI ce Splices J
ket rouymers lgn temp.,
Radiation, Oxygen Exposure of insulation and internal parts to outside conditions Hardening and Cracking Same as effect of corrosion on conductorfor cables (A..1.1).
I-iI i
Seals kpotting)
Compounds (gaskets, sealant) urganic Compounds or cement, Rubber High temp.,
Radiation, Oxygen Moisture intrusion, leakage
- current, Signal noise/
Error, circuit failure Hardening and Cracking Same as effect 01 corrosion on conductor for cables (A..1).
.1 __________
L _____________
VI B-3 Draft November 12, 1999 I*
U.I.I
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Existing 1Further A ino Man~aement Program (AMP)
Evaluation and Technical Basis Evaluation A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.I.]).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.]).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
it, Draft November 12, 1999 VI B-4 A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A. Environmentally qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A*.
Environme ntanly Qualified Equipment Same as effect of corrosion on conductor for cables (A-.1.1).
B. Non environme ntally Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
A.
Environat-,
ntally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non environmi ntA!lY Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.
l).
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Structure and Region of Component Interest Splices Seals (potting)
Compounds (gaskets, sealant)
B. 1.3 Splices Insulators (Heat shrink, Tape)
Material Organic Compounds or cement, Rubber Organic materials.
rubber.
specialty tapes 7
Environ ment High temp.
- hmidity, Mech.
Stress Hi-gn temp.,
Radiation, Oxygen Aging Effect Moisture intrusion, leakage
- current, Signal noise/
Error, circuit failure Leakage current.
Signal noise/
Error, circuit failure Aging Mechanism
- Creep, distortion I
Hardening and Cracking References Same as effect of corrosion on conductor for cables (A.1.1).
Same as effect of' corrosion on conductor for cables (4.1.1).
A. _______________
VI B-5 Draft November 12, 1999 Item B.1.2 I
I I
I Insulators
- shrink, References
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Existing Aging Management Program (AMP)
Evaluation and Technical Basis A. Environmentally Qualified Equipment Same as effect of corrosion on conductorfor cables (A.,ll).
B. Non-environmentally Qualified Equipment Same as effect ofcorrosion on conductorfor cables (A. 1.1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductorfor cables (A. 1.1).
A. Environmentally OJualitled EQuipment Same as effect of corrosion on conductorfor cables (A. 1. 1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
A. Environmentally ualilItel RquIpment Same as effect of corrosion on conductorfor cables (A. 1.1).
B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment Same as effect of corrosion on conductorfor cables (A. I. I).
environme Same as effect of corrosion on conductorfor ntally cables (.4. 1. 1).
Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
VI B-6 Draft November 12, 1999 Further Evaluation A
Environmentally....
Quliie Equipmen A.~
Eniomnal Qulfe Eqimen A.
Environme ntany Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non environme ntaLn Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.I).
A.
Environme ntallv Qualified Equipment Same as effect of corrosion on conductor for cables i
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Structure and Region of I
Item B.2.1 B.2.1 Component Mechanical Connectors Mechanical Connectors Interest Terminal lugs.
compression fittings.
Fusion connectors Contacts/
pins Terminal lugs.
compression fittings.
fusion connectors.
Contactsi pins Environ-Aging Aging ment Effect Mechanism
Nonplated)
Copper (plated/
Nonplated)
Increased circuit resistance.
leakage current.
signal noise/
error Increased circuit resistance, leakage
- current, signal noise/
error Corrosion, oxidation Distortion.
- cracking, work hardening I~~~
.I __________
References Same as effect of corrosion on conductor for cables (A. 1-1).
Same as effect of corrosion on conductor for cables (A. 1. 1).
I VI B-7 Draft November 12, 1999 Vibration.
thermal
- cycling, repeated connect/
disconnect
VI. ELECTRICAL COMPONENTS B. Electrical Connectors Existing Aging Management Program (AMP)
Evaluation and Technical Basis A. Environmentally Qualified Equipment A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for Same as effect of corrosion on conductor for cables (.4. 1. 1).
cables (A. 1.
l).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (4. 1. 1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1)
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1 1).
Same as effect of corrosion on conductor for cableL B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment Same as effect of corrosion on conductor for cables (A. 1.).
environme Same as effect of corrosion on conductor for R!221 cables (A 1.)
Equipmend Same as effect of corrosion on conductor for cables VI B-8 Further Evaluation A.
Environme ntauL Qualified Equipment Same as effect of corrosion on conductor for cable y (A.!.I).
B. Non environme ntauy Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A.
Environme ntauly Oualifien Equipmenc Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Region of Interest Material Organic Compounds Organic Compounds Environ ment I-Ilgn temp.,
Radiation, Oxygen
- Moisture, Contami nants Aging Effect shorting
- Shorting Aging Mechanism Mechanism References Hardening, Cracking Loss of insulating properties Same as effect of corrosion on conductor for cables (A.].]).
Same as effect,i corrosion on conductor for cables (A. 1. 1).
1 ________
.1 _________
1 ________
1 ____
VI B-9 Draft November 12, 1999 Item B.3.1
- structure and Component Terminal Blocks Blocks B 3l 1 1T-,
- -1'in, 12)~
1,.
t"...
I...
References ot.cull assemlllly oc assembtbClI ly
VI.
ELECTRICAL COMPONENTS B. Electrical Connectors Existing Aging Management Program (AMP)
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.].]).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
Evaluation and Technical Basis A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
E~qu pine.
Same as effect of corrosion on conductor for cables (A.1.1).
B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment Same as effect of corrosion on conductor for cables (A. ]. 1).
environn.z Same as effect of corrosion on conductor for ntaig Qualified cables (A.1.1).
E u_ ip me nt Equipment Same as effect of corrosion on conductor for cables (A.1.1).
VI B-10 Further Evaluation A.
Environme ntally Qualified Equipment Same as effect of corrosion on conductor for cables (A,.].).
B. Non environnic ntallv Qualified Equipment Same as effect of corrosion on conducto,.
for cables (A.1.1).
A.
Environme ntaliye qualified Draft November 12, 1999
C.
Electrical Penetration Assemblies (EPA)
C. 1 Modular EPA C. 1.1 O-ring seals C.1.2 Conductor-to-insulator seals C. 1.3 Cable lead wires C.1.4 Interface connectors VI R-1 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS C. Electrical Penetration Assemblies Systems, Structures and Components This review table addresses electric penetration assemblies (EPA). EPAs are used to route electric cable circuits through the containment wall. They provide electrical continuity for the circuit, as well as a pressure boundary for the containment. Individual sub-components for a typical modular type EPA are addressed in terms of aging mechanisms and effects.
System Interfaces Electric penetration assemblies functionally interface with all electric circuits that must be routed through the containment wall.
VI C-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS C. Electrical Penetration Assemblies Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References C. 1.1 Modular O-ring seals Organic High temp.,
Loss of Hardening, Same as effect of Electrical compound Radiation, pressure oxidation corrosion on Penetration Oxygen boundary conductor for Assemblies cables (A. 1.1).
C.1.2 Modular Conductor-to-Fused
- Moisture, Loss of Corrosion Same as effect of Electrical insulator seals glass/metal Contami-pressure corrosion on Penetration Fused nants boundary conductor for Assemblies epoxy/
cables (A. 1.1).
metal Mechanical swage VI C-3 Draft November 12, 1999
VI. ELECTRICAL COMPONENTS C. Electrical Penetration Assemblies Existing Aging Management Program (AMP)
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. l. 1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.]).
Evaluation and Technical Basis A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
I B. Non-environmentally Qualified B. Non-environmentally Qualified Equipment B. Non Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
environme Same as effect of corrosion on conductor for ntally cables (A. 1.1).
Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.]1).
VI C-4 Draft November 12, 1999 Evaluation and Technical Basis I
Further Evaluation A.
Environme ntan!Y Qualified Equipment Same as effect of corrosion on conductor for cables (A.I.1).
B. Non environ Ime ntally Qualified Equipment Same as effect of corrosiou; on conductor for cables (A.1.1).
A.
Environme ntaLy Qualified Equipment Same as effect of corrosioz on conductor for cables (A. I.1).
VI. ELECTRICAL COMPONENTS C. Electrical Penetration Assemblies Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References C. 1.3 Modular Cable lead wires Same as Same as Same as Same as Same as effect of Electrical effect of effect of effect of effect of corrosion on Penetration corrosion on corrosion corrosion on corrosion conductor for Assemblies conductor on conductor for on cables (A. 1.1).
for cables conductor cables conductor (A. 1. 1).
for cables (A.1.]1).
for cables (A.-1. 1).
(A4.1.1,).
C. 1.4 Modular Interface
- Copper, Same as Same as Insulation Same as effect of Electrical connectors
- Polymers, effect of effect of hardening/
corrosion on Penetration Organic corrosion corrosion on
- cracking, conductor for Assemblies Compounds on conductor for
- wear, cables (A. 1. 1).
conductor cables distortion, for cables (A. 1.1).
metal (A. 1.1).
corrosion VI C-5 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS C. Electrical Penetration Assemblies Existing Aging Management Program (AMP)
Evaluation and Technical Basis A. Environmentally Uualitied Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
A. 1i nvironmentallv Qualified Eqluipment Same as effect of corrosion on conductor for cables (Al..1).
R Non-environmentally Oualified Equipment Same as effect of corrosion on conductor for cables (A.1. 1).
Same as effect of corrosion on conductor for cables (A. 1. 1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1.1).
A. Environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
B. Non-environmentally Qualified Equipment Same as effect of corrosion on conductor for cables (A. 1. 1).
Same as effect of corrosion on conductor for cables (A.1.1).
VI C-6 Draft November 12, 1999 Further Evaluation
.1I T I.III
- I 11 L,'
u..
- ]
A..
Enio mnaly Qulfe Eqipm A
It nvlpl*irlmpnTgllV
- iil*llmmmll*ll iP*llUlllmmlcllt A
Qu liie Equipm en A...
Environme Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
B. Non environ nie ntally Qualified Equipment Same as effect of corrosion on conductor for cables (A.l.).
A.
Environme ntany Qualified Equipment Same as effect of corrosion on conductor for cables (A.1.1).
B. Non environrmr.e ntally Qualified Equipment
D.
Electrical Buses D. 1 Isolated Phase Bus D.1.1 Bus assembly D. 1.2 Bus support assembly D. 1.3 Bus enclosure assembly D. 1.4 Baffle bushing assembly D.2 Non-segregated Phase Bus D.2.1 Bus assembly D.2.2 Bus support assembly D.2.3 Bus enclosure assembly D.2.4 Baffle bushing assembly D.3 Segregated Phase Bus D.3.1 Bus assembly D.3.2 Bus support assembly D.3.3 Bus enclosure assembly D.4 Switchyard Bus D.4.1 Bus Enclosure VI R-1 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Systems, Structures and Components This review table addresses electric buses, including isolated phase buses, non-segregated phase buses, segregated phase buses and switchyard buses. Electrical bus assemblies serve as the interconnecting means for distribution of bulk electric power within the plant, from offsite power sources to the plant power system, and from the main generator to the utility power grid.
System Interfaces Electrical bus assemblies interface with high voltage switchgear, power transformers, power circuit breakers, disconnect switches, and generators; bus penetrations route electrical bus bars through structural walls, equipment enclosures and other boundaries VI D-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Structure and Region of I
Environ-Aging Aging Item Component Interest I
Material ment Effect Mechanism References D _
I I 1 solated.Ph--
I*,¢ae l, Al h,:
~orinai Service Conditions, including elevated temperature and oxygen Increased electrical resistance and heating Oxidation, contact surface corrosion Bulletin 79-27 Generic Letter 91 II IN 86-87 IN-86-100
[N 88-55 IN-89-64 IN 91-57 IN 92-09 IN 92-40 IN 93-28 L _________
I ___________
I _________
I _______________
VI D-3 Draft November 12, 1999 Bus J.o Yn~l~
- Bronze, Copper, Stainless Steel
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Existing
[Further Aino Management Program (AMP)
Evaluation and Technical Basis Evaluation Electrical Bus Inspection Program While no requirement currently exists for such a program, periodic visual inspection of electrical buses is a potential method of managing aging degradation for these components. The inspection program should check for indications of any of the identified aging mechanisms, such as surface contamination, oxidation, or corrosion. In addition, infrared thermography can be used to identify hot spots. The visual inspections should also check for settling of support structures, which might place mechanical stress on these components. If no indications are found, this would provide some assurance that aging degradation is not adversely impacting the ability of the components to perform their intended function. If indications of aging degradation are noted, corrective actions can be taken prior to failure occurring.
i Draft November 12, 1999 VI D-4 I No As one potential means of managing aging of electrical buses, an inspection program can be implemented in which periodic visual inspections of the components are performed. The 10 criteria identified in the draft SRP-LR are discussed for such a program below: '
(1) Scope: The inspection program should include all electrical buses that are important to safety. (2) Preventive Actions: Any preventive actions that can be taken to mitigate aging degradation should be identified. (3) Parameter Monitored/Inspected: The parameters to be monitored/inspected should be determined based on the aging mechanisms identified as important for these components. Each of the aging mechanisms presented in this table should be addressed by identifying a parameter or indicator that can be observed during the inspection. (4) Detection: Each of the parameters/indicators should be observed during the inspection to provide some assurance that aging degradation is detected prior to failure. (5) Monitoring and Trending: Any aging indicators noted during the inspection should be quantified, to the extent possible, to allow trending in future inspections. (6) Acceptance Criteria:
An acceptance criteria should be established for each of the parameters/indicators identified such that once the criteria is exceeded, corrective actions must be taken to refurbish or replace the component. (7) Corrective Actions: Based on the acceptance criteria established, corrective actions should be implemented to refurbish or replace components not meeting the minimum acceptance criteria. (8 & 9) Confirmation Process and Administrative controls: A process should be included to ensure that inspection results are reviewed and compared against acceptance criteria, and that corrective actions are implemented, when necessary. Appropriate administrative controls should be in place to ensure that the inspections are performed in a standardized manner and at the proper frequency, and that results are properly documented. (10) Operating experience: Past operating experience should be reviewed and evaluated to identify any plant specific aging issues that should be addressed for these components in the program.
& 1V
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References D. 1.2 Isolated phase Bus support
- Aluminum, Elevated Loss of Corrosion, Same as effect of bus assembly galvanized temperature
- function, vibration, surface oxidation
- metals,
, oxygen change in bus contaminati on the bus assembly porcelain,
- geometry, on in the isolated steel
- cracking, phase bus (D. 1.1).
leakage current D. 1.3 Isolated phase Bus enclosure
- Aluminum, Elevated Loss of Corrosion Same as effect of bus assembly steel temperature
- function, surface oxidation
, moisture, change in bus on the bus assembly oxygen geometry in the isolated phase bus (D. 1.1).
D. 1.4 Isolated phase Baffle bushing
- function, of contact surface oxidation porcelain,
, radiation, change in bus
- surfaces, on the bus assembly silicone
- moisture, geometry, corrosion, in the isolated caulk, steel dust increased contaminati phase bus (D. 1.1).
electrical on resistance and heating, leakage
- current, change in material properties D.2. 1 Non-segregated Bus assembly
- Aluminum, Normal Increased Oxidation, Same as effect of phase bus
- Bronze, Service electrical contact surface oxidation
- Copper, Conditions, resistance surface on the bus assembly Stainless including and heating corrosion in the isolated Steel elevated phase bus (D. 1.1).
temperature and oxygen D.2.2 Non-segregated Bus support
- Aluminum, Elevated Loss of Corrosion, Same as effect of phase bus assembly galvanized temperature
- function, vibration, surface oxidation
- metals,
, oxygen change in bus contaminati on the bus assembty porcelain,
- geometry, on in the isolated steel
- cracking, phase bus (D. 1.1) leakage current VI D-5 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Existing Aging Management Program (AMP)
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus Evaluation and Technical Basis Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus assembly in the assembly in the isolated phase bus (D. 1.1).
isolated phase bus (D1. 1.
J s
a surface oxidation on the bus assembly in the isolh*.e phase bus (D.1.1).
Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the Same as assembly in the isolated phase bus (D. 1. 1).
isolated phase bus (D. 1.1):
effect of surface oxidation on the bus assembly in the isolated phase bus (D.1.1).
VI D-6 Draft November 12, 1999 Further Evaluation Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D.I.1).
Same as effect of surface oxidatio; rn the bus assembly in the isolated phase bus (D..I1).
Same as effect of surface oxidation on the bus assembly in the isolated phase bus (D.1.1).
Same as
,,'*et nf
VI. ELECTRICAL COMPONENTS D. Electrical Buses Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References D.2.3 Non-segregated Bus enclosure
- Aluminum, Elevated Loss of Corrosion Same as effect of" phase bus assembly steel temperature
- function, surface oxidation
, moisture, change in bus on the bus assembly oxygen geometry in the isolated phase bus (D. 1.1).
D.2.4 Non-segregated Baffle bushing
- function, of contact surface oxidation porcelain,
, radiation, change in bus
- surfaces, on the bus assembly silicone
- moisture, geometry, corrosion, in the isolated caulk, steel dust increased contaminati phase bus (D. 1.1).
electrical on resistance and heating, leakage
- current, change in material properties phase bus uaUsemb1ly
- Alumlnum, Bronze,
- Copper, Stainless Steel Normal Service Conditions, including elevated temperature and oxygen increased electrical resistance and heating Oxidation, contact surface corrosion Same as effect of surface oxidation on the bus assen'blv in the isolated phase bus (D. 1.1J.
4 ________
1 ______
1 _______
i ______
I _______
VI D-7 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1. 1).
isolated phase bus (D. 1. 1).
Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1.1).
isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1. 1).
isolated phase bus (D. 1. 1).
VI D-8 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References D.3.2 Segregated Bus support
- Aluminum, Elevated Loss of Corrosion, Same as effect of phase bus assembly galvanized temperature
- function, vibration, surface oxidation
- metals,
, oxygen change in bus contaminati on the bus assembly porcelain,
- geometry, on in the isolated steel
- cracking, phase bus (D. 1. j leakage current D.3.3 Segregated Bus enclosure
- Aluminum, Elevated Loss of Corrosion Same as effect of phase bus assembly steel temperature
- function, surface oxidation
, moisture, change in bus on the bus assembýy oxygen geometry in the isolated phase bus (D. ]. j.
D.4.1 Switchyard bus Bus assembly Aluminum
- Moisture, Increased Oxidation Same as effect of dirt, dust, electrical of contact surface oxidation salt, wind, resistance
- surfaces, on the bus assembly high and heating, corrosion, in the isolated temperature fatigue vibration, phase bus (D. 1.1).
contaminati on VI D-9 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS D. Electrical Buses Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1.1).
isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1.1).
isolated phase bus (D. 1.1).
Same as effect of surface oxidation on the bus Same as effect of surface oxidation on the bus assembly in the No assembly in the isolated phase bus (D. 1.1).
isolated phase bus (D. 1.1).
VI D-10 Draft November 12, 1999
E.
Electrical Insulators E. 1 Station Post Insulators E.1.1 Assembly E.2 Strain/suspension Insulators E.2.1 Assembly VI R-1 Draft November 12, 1999
VI. ELECTRICAL COMPONENTS E. Electrical Insulators Systems, Structures and Components This review table addresses electric insulators, including station post insulators and suspension insulators. Station post insulators and suspension insulators form an integral part of the utility transmission system connecting the power station to offsite power sources, and tying the main generator output to the utility's power grid. Station post insulators provide electrical insulation, spacing, and support between sub-station and switchyard electrical buses and their support structures. Similarly, suspension insulators provide electrical insulation, spacing, and support between transmission line conductors and their transmission structures.
System Interfaces Electric insulators functionally interface with the utility transmission system connecting the power station to offsite power sources, and tying the main generator output to the utility's power grid VI E-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS E. Electrical Insulators Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References P11 1
Qft;,.
m I
n tatLIlPL LU L
insulator Porcelain, Galvanized
- Metals, Stainless
- Steel, Cement Hign temperature
, dirt, dust,
- salt, vibration, and humidity Leakage current, loss of function, cracking Surtace contaminati on or oxidation, loss of material due to
- wear, corrosion, mechanical stress IN 93-95 a __________
L ________
I ________
J _________
I ________
j _____________
VI E-3 Draft November 12, 1999 tA.semlllly
VI. ELECTRICAL COMPONENTS E. Electrical Insulators Existing Aging Management Program (AMP)
Insulator Inspection Program While no requirement currently exists for such a program, periodic visual inspection of insulators is a potential method of managing aging degradation for these components. The inspection program should check for indications of any of the identified aging mechanisms, such as cracking or surface contamination. If no indications are found, this would provide some assurance that aging degradation is not adversely impacting the ability of the components to perform their intended function. If indications of aging degradation are noted, corrective actions can be taken prior to failure occurring.
Evaluation and Technical Basis Draft November 12, 1999 Further Evaluation No VI E-4 I
As one potential means of managing aging of insulators, an inspection program can be implemented in which periodic visual inspections of the components are performed. The 10 criteria identified in the draft SRP-LR are discussed for such a program below:
(1) Scope: The inspection program should include all insulators that are important to safety. (2) Preventive Actions: Any preventive actions that can be taken to mitigate aging degradation should be identified. (3) Parameter Monitored/Inspected: The parameters to be monitored/inspected should be determined based on the aging mechanisms identified as important for these components. Each of the aging mechanisms presented in this table should be addressed by identifying a parameter or indicator that can be observed during the inspection. (4) Detection: Each of the parameters/indicators should be observed during the inspection to provide some assurance that aging degradation is detected prior to failure. (5) Monitoring and Trending: Any aging indicators noted during the inspection should be quantified, to the extent possible, to allow trending in future inspections. (6) Acceptance Criteria:
An acceptance criteria should be established for each of the parameters/indicators identified such that once the criteria is exceeded, corrective actions must be taken to refurbish or replace the component. (7) Corrective Actions: Based on the acceptance criteria established, corrective actions should be implemented to refurbish or replace components not meeting the minimum acceptance criteria. (8 & 9) Confirmation Process and Administrative controls: A process should be included to ensure that inspection results are reviewed and compared against acceptance criteria, and that corrective actions are implemented, when necessary. Appropriate administrative controls should be in place to ensure that the inspections are performed in a standardized manner and at the proper frequency, and that results are properly documented. (10) Operating experience: Past operating experience should be reviewed and evaluated to identify any plant specific aging issues that should be addressed for these components in the program.
VI. ELECTRICAL COMPONENTS E. Electrical Insulators Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References
'-'-I fl-,*.
t
' I ziran ana suspension insulator Assembly Porcelain, Galvanized
- Metals, Stainless
- Steel, Cement High temperature
, dirt, dust,
- salt, vibration, and
- humidity, wind Leakage current, loss of function, cracking Surface contaminati on or oxidation, loss of material due to
- wear, corrosion, mechanical
- stress, vibration IN 93-95
-J _________
- j. _______________
VI E-5 Draft November 12, 1999 rJ,.1. l
VI. ELECTRICAL COMPONENTS E. Electrical Insulators Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluatiot.
Same as effect of surface contamination on the assembly in the station post insulator (E.1.1).
Same as effect ojsurface contamination on the assemoby in the station post insulator (E. 1.1).
Draft November 12, 1999 VI E-6 1"40
F.
Transmission Conductors F. 1 Conductor F.1.1 Assembly VI R-1 Draft November 12, 1999
VI. ELECTRICAL COMPONENTS F. Transmission Conductors Systems, Structures and Components This review table addresses transmission conductors. Transmission conductors form an integral part of the utility transmission system connecting the power station to offsite power sources, and tying the main generator output to the utility's power grid.
System Interfaces Transmission conductors functionally interface with the utility transmission system connecting the power station to offsite power sources, and tying the main generator output to the utility's power grid VI F-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS F. Transmission Conductors Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References F.I.1 Transmission conductors Assembly
- Aluminum, Steel High temperature I vibration, dirt, dust, salt, wind,
- ice, oxygen, and humidity Leakage
- current, fatigue VI F-3 Surface contaminati on or oxidation, corrosion, material loss due to wear None Draft November 12, 1999
VI. ELECTRICAL COMPONENTS F. Transmission Conductors Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluation Transmission Conductor Inspection Program While no requirement currently exists for such a program, periodic visual inspection of transmission conductors is a potential method of managing aging degradation for these components. The inspection program should check for indications of any of the identified aging mechanisms, such as corrosion. In addition, infrared thermography can be used to identify hot spots. If no indications are found, this would provide some assurance that aging degradation is not adversely impacting the ability of the components to perform their intended function. If indications of aging degradation are noted, corrective actions can be taken prior to failure occurring.
Draft November 12, 1999 VI F-4 I
As one potential means of managing aging of transmission conductors, an inspection program can be implemented in which periodic visual inspections of the components are performed. The 10 criteria identified in the draft SRP-LR are discussed for such a program below:
(1) Scope: The inspection program should include all transmission conductors that are important to safety. (2) Preventive Actions:
Any preventive actions that can be taken to mitigate aging degradation should be identified. (3) Parameter Monitored/Inspected: The parameters to be monitored/inspected should be determined based on the aging mechanisms identified as important for these components. Each of the aging mechanisms presented in this table should be addressed by identifying a parameter or indicator that can be observed during the inspection.
(4) Detection: Each of the parameters/indicators should be observed during the inspection to provide some assurance that aging degradation is detected prior to failure. (5) Monitoring and Trending: Any aging indicators noted during the inspection should be quantified, to the extent possible, to allow trending in future inspections. (6) Acceptance Criteria: An acceptance criteria should be established for each of the parameters/indicators identified such that once the criteria is exceeded, corrective actions must be taken to refurbish or replace the component. (7)
Corrective Actions: Based on the acceptance criteria established, corrective actions should be implemented to refurbish or replace components not meeting the minimum acceptance criteria. (8 & 9)
Confirmation Process and Administrative controls: A process should be included to ensure that inspection results are reviewed and compared against acceptance criteria, and that corrective actions are implemented, when necessary. Appropriate administrative controls should be in place to ensure that the inspections are performed in a standardized manner and at the proper frequency, and that results are properly documented. (10)
Operating experience: Past operating experience should be reviewed and evaluated to identify any plant specific aging issues that should be addressed for these components in the program.
I 1,40
G.
Ground Conductors G. 1 Conductor G. I. 1 Assembly VI R-1 Draft November 12, 1999
VI. ELECTRICAL COMPONENTS G. Ground Conductors Systems, Structures and Components This review table addresses ground conductors. The electrical ground conductors make up the plant's electrical ground system. This system establishes the reference ground potential for electrical system voltages in the entire plant. Electric power system voltage measurements are referenced to the ground system, and all protective relaying, basic insulation levels, instrumentation, controls, and metering depend on the design integrity of the plant ground system. Personnel and equipment safety are also dependent on the ground system grid.
System Interfaces Ground conductors functionally interface with all circuits that are electrically connected to ground.
VI G-2 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS G. Ground Conductors Structure and Region of Environ-Aging Aging Item Component Interest Material ment Effect Mechanism References G. 1. 1 Ground Assembly
- Copper, Humidity, Loss of Surface None conductor bronze
- salt, function, contaminati oxygen increased on or electrical oxidation, resistance corrosion, mechanical stress VI G-3 Draft November 12, 1999
VI.
ELECTRICAL COMPONENTS G. Ground Conductors Existing Further Aging Management Program (AMP)
Evaluation and Technical Basis Evaluaticni Ground Conductor Inspection Program Inspection of ground grid conductors may or may not be included in a plant preventive maintenance program. No generally accepted methods to monitor the integrity of cable ground conductors exist. Periodic visual inspection is one potential approach, however, the majority of the ground grid is inaccessible. Indirect indicators of ground integrity are provided through instrument calibration programs, periodic inspection, maintenance, and testing of protective relaying, and the monitoring of electric power system quality and operating parameters.
While no requirement currently exists for such a program, periodic visual inspection of accessible ground conductors is a potential method of managing aging degradation for these components. The inspection program should check for indications of any of the identified aging mechanisms, such as corrosion. In addition, infrared thermography can be used to identify hot spots. Since the majority of the ground grid is inaccessible, indirect indicators of ground integrity should also be included. If no indications are found, this would provide some assurance that aging degradation is not adversely impacting the ability of the components to perform their intended function. If indications of aging degradation are noted, corrective actions can be taken prior to failure occurring.
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As one potential means of managing aging of ground conductors, an inspection program can be implemented in which periodic visual inspections, along with indirect measurements of ground integrity are performed. The 10 criteria identified in the draft SRP LR are discussed for such a program below:
(1) Scope: The inspection program should include all ground conductors that are important to safety. (2) Preventive Actions:
Any preventive actions that can be taken to mitigate aging degradation should be identified. (3) Parameter Monitored/Inspected: The parameters to be monitored/inspected should be determined based on the aging mechanisms identified as important for these components. Each of the aging mechanisms presented in this table should be addressed by identifying a parameter or indicator that can be observed during the inspection.
(4) Detection: Each of the parameters/indicators should be observed during the inspection to provide some assurance that aging degradation is detected prior to failure. (5) Monitoring and Trending: Any aging indicators noted during the inspection should be quantified, to the extent possible, to allow trending in future inspections. (6) Acceptance Criteria: An acceptance criteria should be established for each of the parameters/indicators identified such that once the criteria is exceeded, corrective actions must be taken to refurbish or replace the component. (7)
Corrective Actions: Based on the acceptance criteria established, corrective actions should be implemented to refurbish or replace components not meeting the minimum acceptance criteria. (8& 9)
Confirmation Process and Administrative controls: A process should be included to ensure that inspection results are reviewed and compared against acceptance criteria, and that corrective actions are implemented, when necessary. Appropriate administrative controls should be in place to ensure that the inspections are performed in a standardized manner and at the proper frequency, and that results are properly documented. (10)
Operating experience: Past operating experience should be reviewed and evaluated to identify any plant specific aging issues that should be addressed for these components in the program.
INO
References Code of Federal Regulations, Title 10, Part 50, Section 49, Environmental Qualification of electric Equipment Important to Safety for Nuclear Power Plants.
IEEE Guide P1205, IEEE Guide for Assessing, Monitoring and Mitigating Aging Effects on Class IE Equipment Used in Nuclear Power Generating Stations, 1993.
IEEE Standard 317-83, IEEE Standard for Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations, 1983.
IEEE Standard 323-7 1, IEEE Standard for Qualifying Class JE Equipment for Nuclear Power Generating Stations, 1971.
IEEE Standard 323-74, IEEE Standard for Qualifying Class JE Equipment for Nuclear Power Generating Stations, 1974.
IEEE Standard 3 83-74, IEEE Standard for Type Test of Class JE Electric Cables, Field Splices, and Connections for Nuclear Power Generating Stations, 1974.
NRC Bulletin 79-0 1 B, Environmental Qualification of Class 1E Equipment, January 14, 1980.
NRC Bulletin 79-27, Loss of Non-Class 1E Instrumentation and Control Power System Bus During Operation, November 30, 1979.
NRC Information Notice 86-87, Loss of Offsite Power Upon an Automatic Bus Transfer, October 10, 1986.
NRC Information Notice 86-100, Loss of Offsite Power to Vital Buses at Salem 2, December 12, 1986.
NRC Information Notice 88-55, Potential Problems Caused by Single Failure of an Engineered Safety Feature Swing Bus, August 3, 1988.
NRC Information Notice 89-64, Electrical Bus Bar Failures, September 7, 1989.
NRC Information Notice 91-57, Operational Experience on Bus Transfers, September 19, 1991.
NRC Information Notice 92-09, Overloading and Subsequent Lock Out of Electrical Buses During Accident Conditions, January 30, 1992.
NRC Information Notice 92-40, Inadequate Testing of Emergency Bus Under-voltage Logic Circuitry, May 27, 1992.
NRC Information Notice 93-28, Failure to Consider Loss of DC Bus in the Emergency Core Cooling system Evaluation May Lead to Non-conservative Analysis, April 9, 1993.
NRC Information Notice 93-95, Storm-Related Loss of Offsite Power Events Due to Salt Buildup on Switchyard Insulators, December 13, 1993.
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NRC Regulatory Guide 1.89, Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants, June 1984.
NUREG-05 88, Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment, December 1979.
VI R-2 Draft November 12, 1999
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