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| | issue date = 06/19/2003 | | | issue date = 06/19/2003 |
| | title = Failure of Safety-Related Linestarter Relays at San Onofre Nuclear Generating Station | | | title = Failure of Safety-Related Linestarter Relays at San Onofre Nuclear Generating Station |
| | author name = Beckner W D | | | author name = Beckner W |
| | author affiliation = NRC/NRR/DRIP/RORP | | | author affiliation = NRC/NRR/DRIP/RORP |
| | addressee name = | | | addressee name = |
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| | document type = NRC Information Notice | | | document type = NRC Information Notice |
| | page count = 5 | | | page count = 5 |
| | revision = 0
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| }} | | }} |
| {{#Wiki_filter: | | {{#Wiki_filter:UNITED STATES |
| [[Issue date::June 19, 2003]]
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| NRC INFORMATION NOTICE 2003-06:FAILURE OF SAFETY-RELATED LINESTARTERRELAYS AT SAN ONOFRE NUCLEAR GENERATING STATION | | NUCLEAR REGULATORY COMMISSION |
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| | OFFICE OF NUCLEAR REACTOR REGULATION |
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| | WASHINGTON, DC 20555-0001 June 19, 2003 NRC INFORMATION NOTICE 2003-06: FAILURE OF SAFETY-RELATED LINESTARTER |
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| | RELAYS AT SAN ONOFRE NUCLEAR |
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| | GENERATING STATION |
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|
| ==Addressees== | | ==Addressees== |
| All holders of operating licenses or construction permits for nuclear power reactors, exceptthose that have permanently ceased operations and have certified that fuel has been permanently removed from the reactor. | | All holders of operating licenses or construction permits for nuclear power reactors, except |
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| | those that have permanently ceased operations and have certified that fuel has been |
| | |
| | permanently removed from the reactor. |
|
| |
|
| ==Purpose== | | ==Purpose== |
| The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to informaddressees of recent failures of safety-related valves due to linestarter relay degradatio The degradation was caused by past use of excessive amounts of trichloroethane-based cleaners during preventive maintenanc It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problem However, suggestions in this information notice are not NRC requirements; therefore, no specific action or written response is required. | | The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform |
| | |
| | addressees of recent failures of safety-related valves due to linestarter relay degradation. The |
| | |
| | degradation was caused by past use of excessive amounts of trichloroethane-based cleaners |
| | |
| | during preventive maintenance. It is expected that recipients will review the information for |
| | |
| | applicability to their facilities and consider actions, as appropriate, to avoid similar problems. |
| | |
| | However, suggestions in this information notice are not NRC requirements; therefore, no |
| | |
| | specific action or written response is required. |
|
| |
|
| ==Description of Circumstances== | | ==Description of Circumstances== |
| San Onofre Nuclear Generating Station utilizes reversing linestarters manufactured by SquareD to operate the motors on safety-related motor-operated valve The linestarter consists of two relays that provide 480 volt power to the motor and contain auxiliary contacts associated with interlock and seal-in function The interlock function provides a means to avoid energizing both open and closed relays at the same tim The seal-in function keeps the relay energized until the valve has completed its strok All reversing linestarters have interlock auxiliary contact San Onofre has 172 Square D linestarters associated with safety-related motor-operated valves, 86 in each unit.On August 30, 2002, a Unit 3 low-pressure safety injection (LPSI) pump mini-recirculation valvefailed to open during surveillance testin Subsequent analysis determined that the plastic housing on an auxiliary contact in the associated linestarter was degrade The licensee determined that the auxiliary contact housing degradation was caused by the past use of excessive amounts of Inhibisol, a cleaning solvent based on trichloroethane (TCE). The cleaning solvent caused the plastic to break dow Over time, small amounts of the plastic came loose and interfered with the electrical contacts, resulting in the valve failur In response to the LPSI pump mini-recirculation valve failure, San Onofre developed a plan toinspect a sample of other safety-related linestarters installed in Units 2 and In October 2002, San Onofre completed the inspection of 19 additional linestarter This sample inspection identified two auxiliary contacts that showed signs of chemical attack (i.e., cloudy plastic contact housing); however, both were found to be functiona Subsequently, the licensee developed a risk-informed plan to inspect all safety-related linestarters and replace all auxiliary contacts showing signs of chemical attac The linestarter inspections were scheduled into online and outage maintenance windows, and will be completed by the end of the Unit 2 outage in 2004.On January 18, 2003, during a Unit 3 refueling outage, the quench tank sample containmentisolation valve failed to open during surveillance testin Examination of the contact revealed that a similar chemical attack had occurred and caused the valve failure.On February 10, 2003, during an inspection of Unit 3 LPSI header stop valve linestarters, anauxiliary contact failed on the 20th cycle of the auxiliary contact tes The linestarter inspectionsincluded a test to cycle each auxiliary contact 20 time This auxiliary contact cycle test was performed to determine the functionality of the auxiliary contacts in the linestarter.On Unit 3, all 86 linestarters have been inspected with two surveillance test failures noted andone maintenance test failur The licensee replaced 42 auxiliary contacts from the linestarters due to evidence of chemical attack on the plastic auxiliary contact housin On Unit 2, 33 linestarters have been inspected as of May 2, 2003, with no failures noted; however, four auxiliary contacts showed signs of chemical attack on the plastic contact case.DiscussionAs a result of the valve stroke failure on August 30, 2002, the licensee initiated a laboratoryanalysis of the suspect auxiliary contact from the linestarte The contact was coated with a plastic residue from the deterioration of the plastic switch bodie The licensee concluded that excessive use of cleaning solvents during previous preventive maintenance activities had caused the failure of the contacts. The licensee believes that all damage to the auxiliary contact housings occurred prior to 1989and is showing up in the recent safety-related valve failure The original linestarter preventive maintenance procedure was issued in April 1984, and required the use of cleaning solvents on linestarters, but had no caution regarding the potential for damage to plastic components within the linestarte Also, the procedure did not require visual inspection of internally mounted auxiliary contact assemblie As a result, Inhibisol was used liberally, which allowed the cleaner to come in contact with plastics that were susceptible to chemical degradatio In April 1989, the licensee recognized that TCE-based cleaners were being used improperly and that controls needed to be implemented to prevent future damage to equipment containing plastic The licensee revised the consumables controls manual to restrict the use of TCE-based cleaners on plastics, and provided guidance on the approved method for use of the cleaner (i.e., spray on cloth, then wipe component). Additionally, the linestarter preventive maintenance procedure was revised to caution that cleaning solvents should be used sparingly to avoid damage to plastic component In response to the recent valve failures, the licensee took action on March 7, 2003, to prohibit the use of all TCE-based cleaners for electrical maintenance application The licensee missed several opportunities from plant and industry experience to recognize theneed for an extent-of-condition revie An extent-of-condition review could have identified any equipment degradation that occurred throughout the plant due to improper use of cleaning solvent One of these prior opportunities was the review of Information Notice 93-76, | | San Onofre Nuclear Generating Station utilizes reversing linestarters manufactured by Square |
| "Inadequate Control of Paint and Cleaners for Safety Related Equipment," which the licensee performed in February 199 The review determined that the programs in place were sufficient to avoid problems similar to those discussed in the notic The licensee focused on the TCE-
| | |
| based cleaner controls in place at the time of the information notice review, but overlooked the fact that safety-related equipment could have been damaged prior to the implementation of the controls in April 198 This oversight was a missed opportunity to correct the equipment deficiency that has been revealed by the recent linestarter failures and the discovery of degraded contacts.The San Onofre linestarter experience emphasizes the need to perform an extent-of-conditionreview to determine equipment impact when an improper maintenance practice is recognized and correcte Further, the root cause analysis revealed that past improper use of corrosive cleaners could result in degraded plant equipment that could remain undetected for a considerable length of time before showing up in equipment failures.This information notice requires no specific action or written respons If you have anyquestions about the information in this notice, please contact one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager./RA/William D. Beckner, Program Director Operating Reactor Improvements Program Division of Regulatory Improvement Programs Office of Nuclear Reactor RegulationTechnical Contacts:Gregory G. WarnickVern Hodge623-386-3638301-415-1861 Email:gxw2@nrc.govEmail: cvh@nrc.gov | | D to operate the motors on safety-related motor-operated valves. The linestarter consists of |
| | |
| | two relays that provide 480 volt power to the motor and contain auxiliary contacts associated |
| | |
| | with interlock and seal-in functions. The interlock function provides a means to avoid |
| | |
| | energizing both open and closed relays at the same time. The seal-in function keeps the relay |
| | |
| | energized until the valve has completed its stroke. All reversing linestarters have interlock |
| | |
| | auxiliary contacts. San Onofre has 172 Square D linestarters associated with safety-related |
| | |
| | motor-operated valves, 86 in each unit. |
| | |
| | On August 30, 2002, a Unit 3 low-pressure safety injection (LPSI) pump mini-recirculation valve |
| | |
| | failed to open during surveillance testing. Subsequent analysis determined that the plastic |
| | |
| | housing on an auxiliary contact in the associated linestarter was degraded. The licensee |
| | |
| | determined that the auxiliary contact housing degradation was caused by the past use of |
| | |
| | excessive amounts of Inhibisol, a cleaning solvent based on trichloroethane (TCE). The |
| | |
| | cleaning solvent caused the plastic to break down. Over time, small amounts of the plastic |
| | |
| | came loose and interfered with the electrical contacts, resulting in the valve failure. |
| | |
| | In response to the LPSI pump mini-recirculation valve failure, San Onofre developed a plan to |
| | |
| | inspect a sample of other safety-related linestarters installed in Units 2 and 3. In October 2002, San Onofre completed the inspection of 19 additional linestarters. This sample inspection |
| | |
| | identified two auxiliary contacts that showed signs of chemical attack (i.e., cloudy plastic contact |
| | |
| | housing); however, both were found to be functional. Subsequently, the licensee developed a |
| | |
| | risk-informed plan to inspect all safety-related linestarters and replace all auxiliary contacts |
| | |
| | showing signs of chemical attack. The linestarter inspections were scheduled into online and |
| | |
| | outage maintenance windows, and will be completed by the end of the Unit 2 outage in 2004. |
| | |
| | On January 18, 2003, during a Unit 3 refueling outage, the quench tank sample containment |
| | |
| | isolation valve failed to open during surveillance testing. Examination of the contact revealed |
| | |
| | that a similar chemical attack had occurred and caused the valve failure. |
| | |
| | On February 10, 2003, during an inspection of Unit 3 LPSI header stop valve linestarters, an |
| | |
| | auxiliary contact failed on the 20th cycle of the auxiliary contact test. The linestarter inspections |
| | |
| | included a test to cycle each auxiliary contact 20 times. This auxiliary contact cycle test was |
| | |
| | performed to determine the functionality of the auxiliary contacts in the linestarter. |
| | |
| | On Unit 3, all 86 linestarters have been inspected with two surveillance test failures noted and |
| | |
| | one maintenance test failure. The licensee replaced 42 auxiliary contacts from the linestarters |
| | |
| | due to evidence of chemical attack on the plastic auxiliary contact housing. On Unit 2, |
| | 33 linestarters have been inspected as of May 2, 2003, with no failures noted; however, four |
| | |
| | auxiliary contacts showed signs of chemical attack on the plastic contact case. |
| | |
| | Discussion |
| | |
| | As a result of the valve stroke failure on August 30, 2002, the licensee initiated a laboratory |
| | |
| | analysis of the suspect auxiliary contact from the linestarter. The contact was coated with a |
| | |
| | plastic residue from the deterioration of the plastic switch bodies. The licensee concluded that |
| | |
| | excessive use of cleaning solvents during previous preventive maintenance activities had |
| | |
| | caused the failure of the contacts. |
| | |
| | The licensee believes that all damage to the auxiliary contact housings occurred prior to 1989 and is showing up in the recent safety-related valve failures. The original linestarter preventive |
| | |
| | maintenance procedure was issued in April 1984, and required the use of cleaning solvents on |
| | |
| | linestarters, but had no caution regarding the potential for damage to plastic components within |
| | |
| | the linestarter. Also, the procedure did not require visual inspection of internally mounted |
| | |
| | auxiliary contact assemblies. As a result, Inhibisol was used liberally, which allowed the cleaner |
| | |
| | to come in contact with plastics that were susceptible to chemical degradation. In April 1989, the licensee recognized that TCE-based cleaners were being used improperly and that controls |
| | |
| | needed to be implemented to prevent future damage to equipment containing plastics. The |
| | |
| | licensee revised the consumables controls manual to restrict the use of TCE-based cleaners on |
| | |
| | plastics, and provided guidance on the approved method for use of the cleaner (i.e., spray on |
| | |
| | cloth, then wipe component). Additionally, the linestarter preventive maintenance procedure |
| | |
| | was revised to caution that cleaning solvents should be used sparingly to avoid damage to |
| | |
| | plastic components. In response to the recent valve failures, the licensee took action on |
| | |
| | March 7, 2003, to prohibit the use of all TCE-based cleaners for electrical maintenance |
| | |
| | applications. The licensee missed several opportunities from plant and industry experience to recognize the |
| | |
| | need for an extent-of-condition review. An extent-of-condition review could have identified any |
| | |
| | equipment degradation that occurred throughout the plant due to improper use of cleaning |
| | |
| | solvents. One of these prior opportunities was the review of Information Notice 93-76, Inadequate Control of Paint and Cleaners for Safety Related Equipment, which the licensee |
| | |
| | performed in February 1994. The review determined that the programs in place were sufficient |
| | |
| | to avoid problems similar to those discussed in the notice. The licensee focused on the TCE- |
| | based cleaner controls in place at the time of the information notice review, but overlooked the |
| | |
| | fact that safety-related equipment could have been damaged prior to the implementation of the |
| | |
| | controls in April 1989. This oversight was a missed opportunity to correct the equipment |
| | |
| | deficiency that has been revealed by the recent linestarter failures and the discovery of |
| | |
| | degraded contacts. |
| | |
| | The San Onofre linestarter experience emphasizes the need to perform an extent-of-condition |
| | |
| | review to determine equipment impact when an improper maintenance practice is recognized |
| | |
| | and corrected. Further, the root cause analysis revealed that past improper use of corrosive |
| | |
| | cleaners could result in degraded plant equipment that could remain undetected for a |
| | |
| | considerable length of time before showing up in equipment failures. |
| | |
| | This information notice requires no specific action or written response. If you have any |
| | |
| | questions about the information in this notice, please contact one of the technical contacts |
| | |
| | listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager. |
| | |
| | /RA/ |
| | William D. Beckner, Program Director |
| | |
| | Operating Reactor Improvements Program |
| | |
| | Division of Regulatory Improvement Programs |
| | |
| | Office of Nuclear Reactor Regulation |
| | |
| | Technical Contacts: Gregory G. Warnick Vern Hodge |
| | |
| | 623-386-3638 301-415-1861 Email: gxw2@nrc.gov Email: cvh@nrc.gov |
| | |
| | Attachment: List of Recently Issued NRC Information Notices |
| | |
| | 031700033 DOCUMENT NAME: G:\RORP\OES\Staff Folders\Hodge\san_line inf.wpd |
| | |
| | OFFICE OES:RORP:DRIP Tech Editor RIV EMCB |
| | |
| | NAME CVHodge PKleene GWarnick KParcszewski |
| | |
| | DATE 06/10/2003 06/09/2003 06/12/2003 06/10/2003 OFFICE SC:OES:RORP:DRIP PD:RORP:DRIP |
| | |
| | NAME TReis WDBeckner |
| | |
| | DATE 06/18/2003 06/19/2003 |
| | |
| | Attachment LIST OF RECENTLY ISSUED |
| | |
| | NRC INFORMATION NOTICES |
| | |
| | _____________________________________________________________________________________ |
| | Information Date of |
| | |
| | Notice No. Subject Issuance Issued to |
| | |
| | _____________________________________________________________________________________ |
| | 2003-05 Failure to Detect Freespan 06/05/2003 All holders of operating licenses |
| | |
| | Cracks in PWR Steam or construction permits for |
| | |
| | Generator Tubes pressurized-water reactors |
| | |
| | (PWRs). |
| | |
| | 2002-15, Sup 1 Potential Hydrogen 05/06/2003 All holders of operating licenses |
| | |
| | Combustion Events in BWR for light water reactors, except |
| | |
| | Piping those who have permanently |
| | |
| | ceased operations and have |
| | |
| | certified that fuel has been |
| | |
| | permanently removed from the |
| | |
| | reactor. |
| | |
| | 2002-21, Sup 1 Axial Outside-diameter 04/01/2003 All holders of operating licensees |
| | |
| | Cracking Affecting Thermally for nuclear power reactors, Treated Alloy 600 Steam except those who have |
| | |
| | Generator Tubing permanently ceased operations |
| | |
| | and have certified that fuel has |
| | |
| | been permanently removed from |
| | |
| | the reactor vessel. |
| | |
| | 2003-04 Summary of Fitness-For-Duty 02/06/2003 All holders of operating licensees |
| | |
| | Program Performance Reports for nuclear power reactors, for Calendar Year 2000 except those who have |
| | |
| | permanently ceased operations |
| | |
| | and have certified that fuel has |
| | |
| | been permanently removed from |
| | |
| | the reactor vessel. |
| | |
| | 2003-03 Part 21 - Inadequately Staked 01/27/2003 All holders of operating licenses |
| | |
| | Capscrew Renders Residual or construction permits for |
| | |
| | Heat Removal Pump nuclear power reactors. |
| | |
| | Inoperable |
| | |
| | Note: NRC generic communications may be received in electronic format shortly after they are |
| | |
| | issued by subscribing to the NRC listserver as follows: |
| | To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following |
| | |
| | command in the message portion: |
| | subscribe gc-nrr firstname lastname |
|
| |
|
| ===Attachment:=== | | ______________________________________________________________________________________ |
| List of Recently Issued NRC Information Notices The licensee missed several opportunities from plant and industry experience to recognize theneed for an extent-of-condition revie An extent-of-condition review could have identified any equipment degradation that occurred throughout the plant due to improper use of cleaning solvent One of these prior opportunities was the review of Information Notice 93-76,
| | OL = Operating License |
| "Inadequate Control of Paint and Cleaners for Safety Related Equipment," which the licenseeperformed in February 199 The review determined that the programs in place were sufficient to avoid problems similar to those discussed in the notic The licensee focused on the TCE-
| |
| based cleaner controls in place at the time of the information notice review, but overlooked the fact that safety-related equipment could have been damaged prior to the implementation of the controls in April 198 This oversight was a missed opportunity to correct the equipment deficiency that has been revealed by the recent linestarter failures and the discovery of degraded contacts.The San Onofre linestarter experience emphasizes the need to perform an extent-of-conditionreview to determine equipment impact when an improper maintenance practice is recognized and correcte Further, the root cause analysis revealed that past improper use of corrosive cleaners could result in degraded plant equipment that could remain undetected for a considerable length of time before showing up in equipment failures.This information notice requires no specific action or written respons If you have anyquestions about the information in this notice, please contact one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager./RA/William D. Beckner, Program Director Operating Reactor Improvements Program Division of Regulatory Improvement Programs Office of Nuclear Reactor RegulationTechnical Contacts:Gregory G. WarnickVern Hodge623-386-3638301-415-1861 Email:gxw2@nrc.govEmail: cvh@nrc.gov
| |
|
| |
|
| ===Attachment:===
| | CP = Construction Permit}} |
| List of Recently Issued NRC Information NoticesDISTRIBUTION:ADAMS IN FileADAMS ACCESSION NUMBER:031700033DOCUMENT NAME: G:\RORP\OES\Staff Folders\Hodge\san_line inf.wpdOFFICEOES:RORP:DRIPTech EditorRIVEMCBNAMECVHodgePKleeneGWarnickKParcszewskiDATE06/10/200306/09/200306/12/200306/10/2003OFFICESC:OES:RORP:DRIPPD:RORP:DRIPNAMETReisWDBecknerDATE06/18/200306/19/2003OFFICIAL RECORD COPY
| |
| ______________________________________________________________________________________OL = Operating License CP = Construction PermitAttachment LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICES_____________________________________________________________________________________InformationDate of Notice N SubjectIssuanceIssued to_____________________________________________________________________________________2003-05Failure to Detect FreespanCracks in PWR Steam Generator Tubes06/05/2003All holders of operating licensesor construction permits for pressurized-water reactors (PWRs).2002-15, Sup 1Potential HydrogenCombustion Events in BWR Piping05/06/2003All holders of operating licensesfor light water reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor.2002-21, Sup 1Axial Outside-diameterCracking Affecting Thermally Treated Alloy 600 Steam Generator Tubing04/01/2003All holders of operating licenseesfor nuclear power reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.2003-04Summary of Fitness-For-DutyProgram Performance Reports for Calendar Year 200002/06/2003All holders of operating licenseesfor nuclear power reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.2003-03Part 21 - Inadequately StakedCapscrew Renders Residual Heat Removal Pump Inoperable01/27/2003All holders of operating licensesor construction permits for nuclear power reactors.Note:NRC generic communications may be received in electronic format shortly after they areissued by subscribing to the NRC listserver as follows:To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the followingcommand in the message portion:subscribe gc-nrr firstname lastname}}
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|
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|
| {{Information notice-Nav}} | | {{Information notice-Nav}} |
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Category:NRC Information Notice
MONTHYEARInformation Notice 1991-09, Counterfeiting of Crane Valves2007-09-25025 September 2007 Counterfeiting of Crane Valves Information Notice 2003-06, Failure of Safety-Related Linestarter Relays at San Onofre Nuclear Generating Station2003-06-19019 June 2003 Failure of Safety-Related Linestarter Relays at San Onofre Nuclear Generating Station Information Notice 2002-01, Metal Clad Switchgear Failures and Consequent Losses of Offsite Power2002-01-0808 January 2002 Metal Clad Switchgear Failures and Consequent Losses of Offsite Power Information Notice 1999-28, Recall of Star Brand Fire Protection Sprinkler Heads1999-09-30030 September 1999 Recall of Star Brand Fire Protection Sprinkler Heads Information Notice 1999-27, Malfunction of Source Retraction Mechanism in Cobalt-60 Teletherapy Treatment Units1999-09-0202 September 1999 Malfunction of Source Retraction Mechanism in Cobalt-60 Teletherapy Treatment Units Information Notice 1999-26, Safety and Economic Consequences of Misleading Marketing Information1999-08-24024 August 1999 Safety and Economic Consequences of Misleading Marketing Information Information Notice 1999-25, Year 2000 Contingency Planning Activities1999-08-10010 August 1999 Year 2000 Contingency Planning Activities Information Notice 1999-24, Broad-Scope Licensees' Responsibilities for Reviewing and Approving Unregistered Sealed Sources and Devices1999-07-12012 July 1999 Broad-Scope Licensees' Responsibilities for Reviewing and Approving Unregistered Sealed Sources and Devices Information Notice 1999-23, Safety Concerns Related to Repeated Control Unit Failures of the Nucletron Classic Model High-Dose-Rate Remote Afterloading Brachytherapy Devices1999-07-0606 July 1999 Safety Concerns Related to Repeated Control Unit Failures of the Nucletron Classic Model High-Dose-Rate Remote Afterloading Brachytherapy Devices Information Notice 1999-22, 10CFR 34.43(a)(1); Effective Date for Radiographer Certification and Plans for Enforcement Discretion1999-06-25025 June 1999 10CFR 34.43(a)(1); Effective Date for Radiographer Certification and Plans for Enforcement Discretion Information Notice 1999-21, Recent Plant Events Caused by Human Performance Errors1999-06-25025 June 1999 Recent Plant Events Caused by Human Performance Errors Information Notice 1999-20, Contingency Planning for the Year 2000 Computer Problem1999-06-25025 June 1999 Contingency Planning for the Year 2000 Computer Problem Information Notice 1999-19, Rupture of the Shell Side of a Feedwater Heater at the Point Beach Nuclear Plant1999-06-23023 June 1999 Rupture of the Shell Side of a Feedwater Heater at the Point Beach Nuclear Plant Information Notice 1999-18, Update on Nrc'S Year 2000 Activities for Material Licensees and Fuel Cycle Licensees and Certificate Holders1999-06-14014 June 1999 Update on Nrc'S Year 2000 Activities for Material Licensees and Fuel Cycle Licensees and Certificate Holders Information Notice 1999-17, Problems Associated with Post-Fire Safe-Shutdown Circuit Analyses1999-06-0303 June 1999 Problems Associated with Post-Fire Safe-Shutdown Circuit Analyses Information Notice 1999-16, Federal Bureau of Investigation'S Nuclear Site Security Program1999-05-28028 May 1999 Federal Bureau of Investigation'S Nuclear Site Security Program Information Notice 1999-15, Misapplication for 10CFR Part 71 Transportation Shipping Cask Licensing Basis to 10CFR Part 50 Design Basis1999-05-27027 May 1999 Misapplication for 10CFR Part 71 Transportation Shipping Cask Licensing Basis to 10CFR Part 50 Design Basis Information Notice 1999-14, Unanticipated Reactor Water Draindown at Quad Cities Unit 2, Arkansas Nuclear One Unit 2, & FitzPatrick1999-05-0505 May 1999 Unanticipated Reactor Water Draindown at Quad Cities Unit 2, Arkansas Nuclear One Unit 2, & FitzPatrick Information Notice 1999-13, Insights from NRC Inspections of Low-and Medium-Voltage Circuit Breaker Maintenance Programs1999-04-29029 April 1999 Insights from NRC Inspections of Low-and Medium-Voltage Circuit Breaker Maintenance Programs Information Notice 1999-12, Year 2000 Computer Systems Readiness Audits1999-04-28028 April 1999 Year 2000 Computer Systems Readiness Audits Information Notice 1999-11, Incidents Involving the Use of Radioactive Iodine-1311999-04-16016 April 1999 Incidents Involving the Use of Radioactive Iodine-131 Information Notice 1999-08, Urine Specimen Adulteration1999-03-26026 March 1999 Urine Specimen Adulteration Information Notice 1999-09, Problems Encountered When Manually Editing Treatment Data on the Nucletron Microselectron-HDR (New) Model 105-9991999-03-24024 March 1999 Problems Encountered When Manually Editing Treatment Data on the Nucletron Microselectron-HDR (New) Model 105-999 Information Notice 1999-07, Failed Fire Protection Deluge Valves & Potential Testing Deficiencies in Preaction Sprinkler Systems1999-03-22022 March 1999 Failed Fire Protection Deluge Valves & Potential Testing Deficiencies in Preaction Sprinkler Systems Information Notice 1999-06, 1998 Enforcement Sanctions as a Result of Deliberate Violations of NRC Employee Protection Requirements1999-03-19019 March 1999 1998 Enforcement Sanctions as a Result of Deliberate Violations of NRC Employee Protection Requirements Information Notice 1999-06, 1998 Enforcement Sanctions As a Result of Deliberate Violations of NRC Employee Protection Requirements1999-03-19019 March 1999 1998 Enforcement Sanctions As a Result of Deliberate Violations of NRC Employee Protection Requirements Information Notice 1999-05, Inadvertent Discharge of Carbon Dioxide Fire Protection System and Gas Migration1999-03-0808 March 1999 Inadvertent Discharge of Carbon Dioxide Fire Protection System and Gas Migration Information Notice 1999-04, Unplanned Radiation Exposures to Radiographers, Resulting from Failures to Follow Proper Radiation Safety Procedures1999-03-0101 March 1999 Unplanned Radiation Exposures to Radiographers, Resulting from Failures to Follow Proper Radiation Safety Procedures Information Notice 1999-03, Exothermic Reactors Involving Dried Uranium Oxide Powder (Yellowcake)1999-01-29029 January 1999 Exothermic Reactors Involving Dried Uranium Oxide Powder (Yellowcake) Information Notice 1999-02, Guidance to Users on the Implementation of a New Single-Source Dose-Calculation Formalism and Revised Air-Kerma Strength Standard for Iodine-125 Sealed Sources1999-01-21021 January 1999 Guidance to Users on the Implementation of a New Single-Source Dose-Calculation Formalism and Revised Air-Kerma Strength Standard for Iodine-125 Sealed Sources Information Notice 1999-01, Deterioration of High-Efficiency Particulate Air Filters in a Pressurized Water Reactor Containment Fan Cooler Unit1999-01-20020 January 1999 Deterioration of High-Efficiency Particulate Air Filters in a Pressurized Water Reactor Containment Fan Cooler Unit Information Notice 1998-45, Cavitation Erosion of Letdown Line Orifices Resulting in Fatigue Cracking of Pipe Welds1998-12-15015 December 1998 Cavitation Erosion of Letdown Line Orifices Resulting in Fatigue Cracking of Pipe Welds Information Notice 1998-44, Ten-Year Inservice Inspection (ISI) Program Update for Licensees That Intend to Implement Risk-Informed ISI of Piping1998-12-10010 December 1998 Ten-Year Inservice Inspection (ISI) Program Update for Licensees That Intend to Implement Risk-Informed ISI of Piping Information Notice 1998-43, Leaks in Emergency Diesel Generator Lubricating Oil & Jacket Cooling Water Piping1998-12-0404 December 1998 Leaks in Emergency Diesel Generator Lubricating Oil & Jacket Cooling Water Piping Information Notice 1998-42, Implementation of 10 CFR 55.55a(g) Inservice Inspection Requirements1998-12-0101 December 1998 Implementation of 10 CFR 55.55a(g) Inservice Inspection Requirements Information Notice 1998-41, Spurious Shutdown of Emergency Diesel Generators from Design Oversight1998-11-20020 November 1998 Spurious Shutdown of Emergency Diesel Generators from Design Oversight Information Notice 1998-41, Spurious Shutdown of Emergency Diesel Generators From Design Oversight1998-11-20020 November 1998 Spurious Shutdown of Emergency Diesel Generators From Design Oversight Information Notice 1998-39, Summary of Fitness-for-Duty Program Performance Reports for Calendar Years 1996 and 19971998-10-30030 October 1998 Summary of Fitness-for-Duty Program Performance Reports for Calendar Years 1996 and 1997 Information Notice 1998-40, Design Deficiencies Can Lead to Reduced ECCS Pump Net Positive Suction Head During Design-Basis Accidents1998-10-26026 October 1998 Design Deficiencies Can Lead to Reduced ECCS Pump Net Positive Suction Head During Design-Basis Accidents Information Notice 1990-66, Incomplete Draining and Drying of Shipping Casks1998-10-25025 October 1998 Incomplete Draining and Drying of Shipping Casks Information Notice 1998-38, Metal-Clad Circuit Breaker Maintenance Issues Identified by NRC Inspections1998-10-15015 October 1998 Metal-Clad Circuit Breaker Maintenance Issues Identified by NRC Inspections Information Notice 1998-37, Eligibility of Operator License Applicants1998-10-0101 October 1998 Eligibility of Operator License Applicants Information Notice 1998-36, Inadequate or Poorly Controlled, Non-Safety-Related Maintenance Activities Unnecessarily Challenged Safety Systems1998-09-18018 September 1998 Inadequate or Poorly Controlled, Non-Safety-Related Maintenance Activities Unnecessarily Challenged Safety Systems Information Notice 1998-34, Configuration Control Errors1998-08-28028 August 1998 Configuration Control Errors Information Notice 1998-33, NRC Regulations Prohibit Agreements That Restrict or Discourage an Employee from Participating in Protected Activities1998-08-28028 August 1998 NRC Regulations Prohibit Agreements That Restrict or Discourage an Employee from Participating in Protected Activities Information Notice 1998-31, Fire Protection System Design Deficiencies and Common-Mode Flooding of Emergency Core Cooling System Rooms at Washington Nuclear Project Unit 21998-08-18018 August 1998 Fire Protection System Design Deficiencies and Common-Mode Flooding of Emergency Core Cooling System Rooms at Washington Nuclear Project Unit 2 Information Notice 1998-30, Effect of Year 2000 Computer Problem on NRC Licensees and Certificate Holders1998-08-12012 August 1998 Effect of Year 2000 Computer Problem on NRC Licensees and Certificate Holders Information Notice 1998-29, Predicted Increase in Fuel Rod Cladding Oxidation1998-08-0303 August 1998 Predicted Increase in Fuel Rod Cladding Oxidation Information Notice 1998-28, Development of Systematic Sample Plan for Operator Licensing Examinations1998-07-31031 July 1998 Development of Systematic Sample Plan for Operator Licensing Examinations Information Notice 1998-27, Steam Generator Tube End Cracking1998-07-24024 July 1998 Steam Generator Tube End Cracking 2007-09-25
[Table view] |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, DC 20555-0001 June 19, 2003 NRC INFORMATION NOTICE 2003-06: FAILURE OF SAFETY-RELATED LINESTARTER
RELAYS AT SAN ONOFRE NUCLEAR
GENERATING STATION
Addressees
All holders of operating licenses or construction permits for nuclear power reactors, except
those that have permanently ceased operations and have certified that fuel has been
permanently removed from the reactor.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform
addressees of recent failures of safety-related valves due to linestarter relay degradation. The
degradation was caused by past use of excessive amounts of trichloroethane-based cleaners
during preventive maintenance. It is expected that recipients will review the information for
applicability to their facilities and consider actions, as appropriate, to avoid similar problems.
However, suggestions in this information notice are not NRC requirements; therefore, no
specific action or written response is required.
Description of Circumstances
San Onofre Nuclear Generating Station utilizes reversing linestarters manufactured by Square
D to operate the motors on safety-related motor-operated valves. The linestarter consists of
two relays that provide 480 volt power to the motor and contain auxiliary contacts associated
with interlock and seal-in functions. The interlock function provides a means to avoid
energizing both open and closed relays at the same time. The seal-in function keeps the relay
energized until the valve has completed its stroke. All reversing linestarters have interlock
auxiliary contacts. San Onofre has 172 Square D linestarters associated with safety-related
motor-operated valves, 86 in each unit.
On August 30, 2002, a Unit 3 low-pressure safety injection (LPSI) pump mini-recirculation valve
failed to open during surveillance testing. Subsequent analysis determined that the plastic
housing on an auxiliary contact in the associated linestarter was degraded. The licensee
determined that the auxiliary contact housing degradation was caused by the past use of
excessive amounts of Inhibisol, a cleaning solvent based on trichloroethane (TCE). The
cleaning solvent caused the plastic to break down. Over time, small amounts of the plastic
came loose and interfered with the electrical contacts, resulting in the valve failure.
In response to the LPSI pump mini-recirculation valve failure, San Onofre developed a plan to
inspect a sample of other safety-related linestarters installed in Units 2 and 3. In October 2002, San Onofre completed the inspection of 19 additional linestarters. This sample inspection
identified two auxiliary contacts that showed signs of chemical attack (i.e., cloudy plastic contact
housing); however, both were found to be functional. Subsequently, the licensee developed a
risk-informed plan to inspect all safety-related linestarters and replace all auxiliary contacts
showing signs of chemical attack. The linestarter inspections were scheduled into online and
outage maintenance windows, and will be completed by the end of the Unit 2 outage in 2004.
On January 18, 2003, during a Unit 3 refueling outage, the quench tank sample containment
isolation valve failed to open during surveillance testing. Examination of the contact revealed
that a similar chemical attack had occurred and caused the valve failure.
On February 10, 2003, during an inspection of Unit 3 LPSI header stop valve linestarters, an
auxiliary contact failed on the 20th cycle of the auxiliary contact test. The linestarter inspections
included a test to cycle each auxiliary contact 20 times. This auxiliary contact cycle test was
performed to determine the functionality of the auxiliary contacts in the linestarter.
On Unit 3, all 86 linestarters have been inspected with two surveillance test failures noted and
one maintenance test failure. The licensee replaced 42 auxiliary contacts from the linestarters
due to evidence of chemical attack on the plastic auxiliary contact housing. On Unit 2,
33 linestarters have been inspected as of May 2, 2003, with no failures noted; however, four
auxiliary contacts showed signs of chemical attack on the plastic contact case.
Discussion
As a result of the valve stroke failure on August 30, 2002, the licensee initiated a laboratory
analysis of the suspect auxiliary contact from the linestarter. The contact was coated with a
plastic residue from the deterioration of the plastic switch bodies. The licensee concluded that
excessive use of cleaning solvents during previous preventive maintenance activities had
caused the failure of the contacts.
The licensee believes that all damage to the auxiliary contact housings occurred prior to 1989 and is showing up in the recent safety-related valve failures. The original linestarter preventive
maintenance procedure was issued in April 1984, and required the use of cleaning solvents on
linestarters, but had no caution regarding the potential for damage to plastic components within
the linestarter. Also, the procedure did not require visual inspection of internally mounted
auxiliary contact assemblies. As a result, Inhibisol was used liberally, which allowed the cleaner
to come in contact with plastics that were susceptible to chemical degradation. In April 1989, the licensee recognized that TCE-based cleaners were being used improperly and that controls
needed to be implemented to prevent future damage to equipment containing plastics. The
licensee revised the consumables controls manual to restrict the use of TCE-based cleaners on
plastics, and provided guidance on the approved method for use of the cleaner (i.e., spray on
cloth, then wipe component). Additionally, the linestarter preventive maintenance procedure
was revised to caution that cleaning solvents should be used sparingly to avoid damage to
plastic components. In response to the recent valve failures, the licensee took action on
March 7, 2003, to prohibit the use of all TCE-based cleaners for electrical maintenance
applications. The licensee missed several opportunities from plant and industry experience to recognize the
need for an extent-of-condition review. An extent-of-condition review could have identified any
equipment degradation that occurred throughout the plant due to improper use of cleaning
solvents. One of these prior opportunities was the review of Information Notice 93-76, Inadequate Control of Paint and Cleaners for Safety Related Equipment, which the licensee
performed in February 1994. The review determined that the programs in place were sufficient
to avoid problems similar to those discussed in the notice. The licensee focused on the TCE-
based cleaner controls in place at the time of the information notice review, but overlooked the
fact that safety-related equipment could have been damaged prior to the implementation of the
controls in April 1989. This oversight was a missed opportunity to correct the equipment
deficiency that has been revealed by the recent linestarter failures and the discovery of
degraded contacts.
The San Onofre linestarter experience emphasizes the need to perform an extent-of-condition
review to determine equipment impact when an improper maintenance practice is recognized
and corrected. Further, the root cause analysis revealed that past improper use of corrosive
cleaners could result in degraded plant equipment that could remain undetected for a
considerable length of time before showing up in equipment failures.
This information notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the technical contacts
listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.
/RA/
William D. Beckner, Program Director
Operating Reactor Improvements Program
Division of Regulatory Improvement Programs
Office of Nuclear Reactor Regulation
Technical Contacts: Gregory G. Warnick Vern Hodge
623-386-3638 301-415-1861 Email: gxw2@nrc.gov Email: cvh@nrc.gov
Attachment: List of Recently Issued NRC Information Notices
031700033 DOCUMENT NAME: G:\RORP\OES\Staff Folders\Hodge\san_line inf.wpd
OFFICE OES:RORP:DRIP Tech Editor RIV EMCB
NAME CVHodge PKleene GWarnick KParcszewski
DATE 06/10/2003 06/09/2003 06/12/2003 06/10/2003 OFFICE SC:OES:RORP:DRIP PD:RORP:DRIP
NAME TReis WDBeckner
DATE 06/18/2003 06/19/2003
Attachment LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________________
Information Date of
Notice No. Subject Issuance Issued to
_____________________________________________________________________________________
2003-05 Failure to Detect Freespan 06/05/2003 All holders of operating licenses
Cracks in PWR Steam or construction permits for
Generator Tubes pressurized-water reactors
(PWRs).
2002-15, Sup 1 Potential Hydrogen 05/06/2003 All holders of operating licenses
Combustion Events in BWR for light water reactors, except
Piping those who have permanently
ceased operations and have
certified that fuel has been
permanently removed from the
reactor.
2002-21, Sup 1 Axial Outside-diameter 04/01/2003 All holders of operating licensees
Cracking Affecting Thermally for nuclear power reactors, Treated Alloy 600 Steam except those who have
Generator Tubing permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor vessel.
2003-04 Summary of Fitness-For-Duty 02/06/2003 All holders of operating licensees
Program Performance Reports for nuclear power reactors, for Calendar Year 2000 except those who have
permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor vessel.
2003-03 Part 21 - Inadequately Staked 01/27/2003 All holders of operating licenses
Capscrew Renders Residual or construction permits for
Heat Removal Pump nuclear power reactors.
Inoperable
Note: NRC generic communications may be received in electronic format shortly after they are
issued by subscribing to the NRC listserver as follows:
To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following
command in the message portion:
subscribe gc-nrr firstname lastname
______________________________________________________________________________________
OL = Operating License
CP = Construction Permit
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list | - Information Notice 2003-01, Failure of a Boiling Water Reactor Target Rock Main Steam Safety/Relief Valve (15 January 2003)
- Information Notice 2003-02, Recent Experience with Reactor Coolant System Leakage & Boric Acid Corrosion (16 January 2003, Topic: Boric Acid, Weld Overlay)
- Information Notice 2003-03, Part 21 - Inadequately Staked Capscrew Renders Residual Heat Removal Pump Inoperable (27 January 2003, Topic: Boric Acid)
- Information Notice 2003-04, Summary of Fitness-For-Duty Program Performance Reports for Calendar Year 2000 (6 February 2003, Topic: Boric Acid, Fitness for Duty)
- Information Notice 2003-06, Failure of Safety-Related Linestarter Relays at San Onofre Nuclear Generating Station (19 June 2003)
- Information Notice 2003-08, Potential Flooding Through Unsealed Concrete Floor Cracks (25 June 2003)
- Information Notice 2003-09, Source Positioning Errors and System Malfunctions Administration of Intravascular Brachytherapy (16 July 2003, Topic: Brachytherapy)
- Information Notice 2003-11, Leakage Found on Bottom-Mounted Instrumentation Nozzles (8 January 2004, Topic: Unanalyzed Condition, Nondestructive Examination)
- Information Notice 2003-12, Problems Involved In Monitoring Dose to Hands Resulting from Handling of Radiopharmaceuticals (22 August 2003)
- Information Notice 2003-12, Problems Involved in Monitoring Dose to Hands Resulting from Handling of Radiopharmaceuticals (22 August 2003)
- Information Notice 2003-13, Steam Generator Tube Degradation at Diablo Canyon (28 August 2003)
- Information Notice 2003-14, Potential Vulnerability of Plant Computer Network to Worm Infection (29 August 2003)
- Information Notice 2003-15, Importance of Followup Activities in Resolving Maintenance Issues (5 September 2003)
- Information Notice 2003-17, Reduced Service Life of Automatic Switch Company (ASCO) Solenoid Valves With Buna-N Material (29 September 2003)
- Information Notice 2003-17, Reduced Service Life of Automatic Switch Company (Asco) Solenoid Valves with Buna-N Material (29 September 2003)
- Information Notice 2003-18, General Electric Type Sbm Control Switches with Defective Cam Followers (26 September 2003)
- Information Notice 2003-18, General Electric Type SBM Control Switches with Defective Cam Followers (26 September 2003)
- Information Notice 2003-19, Unanalyzed Condition of Reactor Coolant Pump Seal Leakoff Line During Postulated Fire Scenarios or Station Blackout (6 October 2003, Topic: Safe Shutdown, Unanalyzed Condition, Boric Acid)
- Information Notice 2003-20, Derating Whiting Cranes Purchased Before 1980 (22 October 2003, Topic: Unanalyzed Condition)
- Information Notice 2003-21, High-Dose-Rate-Remote-Afterloader Equipment Failure (24 November 2003, Topic: Unanalyzed Condition, Brachytherapy)
- Information Notice 2003-22, Heightened Awareness for Patients Containing Detectable Amounts of Radiation from Medical Administrations (9 December 2003, Topic: Unanalyzed Condition, Brachytherapy)
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