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| ==Description of Circumstances== | | ==Description of Circumstances== |
| The first incident occurred when an operator may have been able to open theshielded door of an irradiator with the sources in the exposed position.After irradiation of several pocket dosimeters, the operator opened theshielded door of the irradiator to retrieve the dosimeters, but did notperform a radiation survey, as required by the facility's internal procedures,before opening the door. Twice, the operator placed one hand inside theirradiator to retrieve the dosimeters. Subsequently, the operator observedthat the unit timer continued to count, indicating that the sources remainedin the exposed position. The operator checked his personal pocket dosimeter,but did not note an unusual reading. However, the operator did not report theincident until questioned by the radiation safety officer, who had noted anunusually high dosimetry report of 3.55 millisievert (355 mrem) deep doseequivalent for the worker. The dose to the right hand was calculated to be amaximum of 12.5 millisievert (1.25 rem).The design of the irradiator includes two interconnected interlock systems,intended to prevent unshielded exposure of the sources. These include a doorinterlock system -- designed to allow opening of the shielded door only afterthe sources are placed in the fully shielded position -- and a source exposure-.interlock system -- designed to secure the sources in the fully shieldedtDR FE E NO r/C9 03 ?C 0t, II kk JIIN 96-35June 11, 1996 position whenever the shielded door is open or unlocked. The manufacturer ofthe irradiator indicated that under normal operations, either systemindividually wouldiprevent inadvertent access to the unshielded sources.Following the incident, the manufacturer of the irradiator was requested toperform an onsite inspection of the irradiator and facilities. During theinspection, the manufacturer noted:(1) the irradiator was located in an area that was not climate-controlled;(2) internal components of the irradiator were in a degraded state;(3) maintenance of the irradiator had last been performed approximately10 years ago; and(4) a return spring, integral to the source exposure safety interlocksystem, was broken. The manufacturer indicated that the lack ofenvironmental control may have accelerated the degradation of theinternal components of the irradiator, and that the lack of periodicmaintenance of the irradiator may have contributed to the failure ofthe return spring.The broken return spring may have caused the source securing mechanism of thesource exposure interlock system to malfunction, possibly allowing exposure ofthe sources after the shielded door was unlocked and opened. However, duringthe post-incident investigation, neither the manufacturer nor the licenseewere able to identify a failed component of either interlock system that couldhave allowed the shielded door to be opened with the sources in the exposedposition. The manufacturer indicated that the design of the source exposuremechanism -- the operator must manually move the sources from the shielded tothe exposed position with a lever -- would have provided the operator with apositive indication of source position even if the interlock systems failed.Source position would have been further provided by a series of green and redsource position lights on the irradiator.The operator's actions indicate either a lack of training on the properfunctioning and use of the irradiator, a lack of understanding of the trainingprovided, and/or a disregard for following the established operating andsafety procedures. The operator indicated that the timer continued to countwhen the shielded door was opened. However, the manufacturer reported thatthe timer automatically activates whenever the source lever is manually movedto one of the two source exposed positions and the lever is fully engaged inthe source slot, and stops counting as soon as the lever is moved from thefully engaged position. The fact that the timer continued to count indicatesthat the operator had not moved the sources from the fully exposed and engagedposition. The licensee reported that the operator had been trained in theoperation of the irradiator and was listed as an authorized user, but that theirradiator was used infrequently and that this was only the operator's seconduse of the irradiator since being trained.The second incident occurred when a maintenance worker preparing to performmaintenance on an irradiator bypassed the irradiator door interlock system toobserve movement of the inner irradiation chamber. The maintenance was being K>IN 96-35June 11, 1996 performed to correct previous maintenance that resulted in the irradiator notfunctioning properly. The maintenance worker was unaware that, although thesources remained shielded during movement of the irradiation chamber from theload to irradiate position, high levels of radiation scatter would be present.The maintenance worker, upon hearing the in-room monitor alarm, immediatelyreturned the radiation chamber to the 'load' position (maximum shielding).Although the maintenance worker was familiar with the operation of theirradiator and had been responsible for its maintenance for nearly 15 years,the worker apparently had not been given formal training on radiation safetyor the operation and maintenance of the irradiator. The maintenance workerwas not aware of the scatter radiation and assumed that since the sources werenot directly exposed, radiation from the sources would be contained within thedevice.During this incident, another worker, hired to perform contract maintenance onthe irradiator, was also in the room near the irradiator. Neither worker woredosimetry nor had any documented training in radiation safety. Therefore,their doses could only be calculated based on their recollection and wereestimated to both be approximately 4 microsievert (0.4 mrem) whole body.DiscussionAlthough neither incident resulted in doses in excess of regulatory limits,the doses received in both incidents were unnecessary and possibly could havebeen avoided with proper training and routine equipment maintenance. Asimilar incident in 1984, where a door interlock failed, resulted in theoperator being exposed to 222 terabequerel (6000 curies) of cesium-137.The first incident clearly demonstrates the need to perform appropriatemaintenance on these types of units. Even though these units are designedwith interlocks and safety features intended to prevent inadvertent exposures,the components of these systems depend on adequate maintenance to functionproperly. Failure to properly maintain these systems and provide appropriatetraining could result in unnecessary exposures. Manufacturers of these typesof irradiators frequently provide initial and periodic training on theoperation of their units and, in some cases, training on other manufacturers'units, as well. Initial training is typically a condition of the license and,therefore, must be provided to all irradiator users and maintenance personnel.Periodic refresher training is also beneficial as a reminder for workingsafely around the irradiator and provides for a means to receive ordisseminate additional or updated information.In addition, most manufacturers have a recommended schedule of maintenanceand/or recommended preventative/periodic maintenance that should be performed.Users of these types of irradiators should evaluate their usage to determinethe applicability of the recommended maintenance to their situation and usage.Users who operate their unit more than usual or who use their units underharsh conditions should consider the need for stepped-up maintenance or | | The first incident occurred when an operator may have been able to open theshielded door of an irradiator with the sources in the exposed position.After irradiation of several pocket dosimeters, the operator opened theshielded door of the irradiator to retrieve the dosimeters, but did notperform a radiation survey, as required by the facility's internal procedures,before opening the door. Twice, the operator placed one hand inside theirradiator to retrieve the dosimeters. Subsequently, the operator observedthat the unit timer continued to count, indicating that the sources remainedin the exposed position. The operator checked his personal pocket dosimeter,but did not note an unusual reading. However, the operator did not report theincident until questioned by the radiation safety officer, who had noted anunusually high dosimetry report of 3.55 millisievert (355 mrem) deep doseequivalent for the worker. The dose to the right hand was calculated to be amaximum of 12.5 millisievert (1.25 rem).The design of the irradiator includes two interconnected interlock systems,intended to prevent unshielded exposure of the sources. These include a doorinterlock system -- designed to allow opening of the shielded door only afterthe sources are placed in the fully shielded position -- and a source exposure-.interlock system -- designed to secure the sources in the fully shieldedtDR FE E NO r/C9 03 ?C 0t, II |
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| '-> IN 96-35June 11, 1996 shortened maintenance intervals. In addition, each manufacturer's recommendedmaintenance may vary according to the specific unit or type of use.Therefore, personis performing maintenance on their unit may require specificmaintenance training for their unit.Users who are not aware of the required training for their unit, or who wishto receive information concerning training in general, should consult theirlicense, licensing authority, or the manufacturer of the unit. RegulatoryGuide 10.9, provides additional guidance in this area and may assist personswho wish to develop a training and maintenance program. Users who wish toreceive additional information concerning recommended maintenance for theirunit should contact the manufacturer of the unit. In addition, third-partyservice companies may also be available for training and maintenance servicesfor these types of irradiators.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.I3W¶flstn8by9WWstIADonald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Douglas Broaddus, NMSS(301) 415-5847Internet:dab~nrc.govAnthony Kirkwood, NMSS(301) 415-6140Internet:ask~nrc.gov
| | kk JIIN 96-35June 11, 1996 position whenever the shielded door is open or unlocked. The manufacturer ofthe irradiator indicated that under normal operations, either systemindividually wouldiprevent inadvertent access to the unshielded sources.Following the incident, the manufacturer of the irradiator was requested toperform an onsite inspection of the irradiator and facilities. During theinspection, the manufacturer noted:(1) the irradiator was located in an area that was not climate-controlled;(2) internal components of the irradiator were in a degraded state;(3) maintenance of the irradiator had last been performed approximately10 years ago; and(4) a return spring, integral to the source exposure safety interlocksystem, was broken. The manufacturer indicated that the lack ofenvironmental control may have accelerated the degradation of theinternal components of the irradiator, and that the lack of periodicmaintenance of the irradiator may have contributed to the failure ofthe return spring.The broken return spring may have caused the source securing mechanism of thesource exposure interlock system to malfunction, possibly allowing exposure ofthe sources after the shielded door was unlocked and opened. However, duringthe post-incident investigation, neither the manufacturer nor the licenseewere able to identify a failed component of either interlock system that couldhave allowed the shielded door to be opened with the sources in the exposedposition. The manufacturer indicated that the design of the source exposuremechanism -- the operator must manually move the sources from the shielded tothe exposed position with a lever -- would have provided the operator with apositive indication of source position even if the interlock systems failed.Source position would have been further provided by a series of green and redsource position lights on the irradiator.The operator's actions indicate either a lack of training on the properfunctioning and use of the irradiator, a lack of understanding of the trainingprovided, and/or a disregard for following the established operating andsafety procedures. The operator indicated that the timer continued to countwhen the shielded door was opened. However, the manufacturer reported thatthe timer automatically activates whenever the source lever is manually movedto one of the two source exposed positions and the lever is fully engaged inthe source slot, and stops counting as soon as the lever is moved from thefully engaged position. The fact that the timer continued to count indicatesthat the operator had not moved the sources from the fully exposed and engagedposition. The licensee reported that the operator had been trained in theoperation of the irradiator and was listed as an authorized user, but that theirradiator was used infrequently and that this was only the operator's seconduse of the irradiator since being trained.The second incident occurred when a maintenance worker preparing to performmaintenance on an irradiator bypassed the irradiator door interlock system toobserve movement of the inner irradiation chamber. The maintenance was being |
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| ===Attachments:===
| | K>IN 96-35June 11, 1996 performed to correct previous maintenance that resulted in the irradiator notfunctioning properly. The maintenance worker was unaware that, although thesources remained shielded during movement of the irradiation chamber from theload to irradiate position, high levels of radiation scatter would be present.The maintenance worker, upon hearing the in-room monitor alarm, immediatelyreturned the radiation chamber to the 'load' position (maximum shielding).Although the maintenance worker was familiar with the operation of theirradiator and had been responsible for its maintenance for nearly 15 years,the worker apparently had not been given formal training on radiation safetyor the operation and maintenance of the irradiator. The maintenance workerwas not aware of the scatter radiation and assumed that since the sources werenot directly exposed, radiation from the sources would be contained within thedevice.During this incident, another worker, hired to perform contract maintenance onthe irradiator, was also in the room near the irradiator. Neither worker woredosimetry nor had any documented training in radiation safety. Therefore,their doses could only be calculated based on their recollection and wereestimated to both be approximately 4 microsievert (0.4 mrem) whole body.DiscussionAlthough neither incident resulted in doses in excess of regulatory limits,the doses received in both incidents were unnecessary and possibly could havebeen avoided with proper training and routine equipment maintenance. Asimilar incident in 1984, where a door interlock failed, resulted in theoperator being exposed to 222 terabequerel (6000 curies) of cesium-137.The first incident clearly demonstrates the need to perform appropriatemaintenance on these types of units. Even though these units are designedwith interlocks and safety features intended to prevent inadvertent exposures,the components of these systems depend on adequate maintenance to functionproperly. Failure to properly maintain these systems and provide appropriatetraining could result in unnecessary exposures. Manufacturers of these typesof irradiators frequently provide initial and periodic training on theoperation of their units and, in some cases, training on other manufacturers'units, as well. Initial training is typically a condition of the license and,therefore, must be provided to all irradiator users and maintenance personnel.Periodic refresher training is also beneficial as a reminder for workingsafely around the irradiator and provides for a means to receive ordisseminate additional or updated information.In addition, most manufacturers have a recommended schedule of maintenanceand/or recommended preventative/periodic maintenance that should be performed.Users of these types of irradiators should evaluate their usage to determinethe applicability of the recommended maintenance to their situation and usage.Users who operate their unit more than usual or who use their units underharsh conditions should consider the need for stepped-up maintenance or |
| 1. List of Recently issued NMSS Information Notices2. List of Recently issued NRC Information NoticesDOCUMENT NAME: 96-35.INTo receive a copy of this document, Indicate In the box: C' = Copy without attachment/enclosure *E' -Copy with attachmentjendosure N
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| * No copy* See previous concurrenceOFFICE IIMAB* [ClIMAB* [C Tech Editor* l IMOB* [C IMNS* I C,NAME IDBroaddus* LCamper lEKraus _KRamsey jDCof'DATE 14/17/96 5/28/96 4/01/96 5/31/96 6/4 96 11OFFICIAL RECORD COPY j;IN 96-XXMay XX, 1996 Users who are not aware of the required training for their unit, or who wishto receive information concerning training in general, should consult theirlicense, licensing authority, or the manufacturer of the unit. RegulatoryGuide 10.9, provides additional guidance in this area and may assist personswho wish to develop a training and maintenance program. Users who wish toreceive additional information concerning recommended maintenance for theirunit should contact the manufacturer of the unit. In addition, third-partyservice companies may also be available for training and maintenance servicesfor these types of irradiators.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Douglas Broaddus, NMSS(301) 415-5847Anthony Kirkwood, NMSS(301) 415-6140
| | '-> IN 96-35June 11, 1996 shortened maintenance intervals. In addition, each manufacturer's recommendedmaintenance may vary according to the specific unit or type of use.Therefore, personis performing maintenance on their unit may require specificmaintenance training for their unit.Users who are not aware of the required training for their unit, or who wishto receive information concerning training in general, should consult theirlicense, licensing authority, or the manufacturer of the unit. RegulatoryGuide 10.9, provides additional guidance in this area and may assist personswho wish to develop a training and maintenance program. Users who wish toreceive additional information concerning recommended maintenance for theirunit should contact the manufacturer of the unit. In addition, third-partyservice companies may also be available for training and maintenance servicesfor these types of irradiators.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.I3W¶flstn8by9WWstIADonald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Douglas Broaddus, NMSS(301) 415-5847Internet:dab~nrc.govAnthony Kirkwood, NMSS(301) 415-6140Internet:ask~nrc.govAttachments:1. List of Recently issued NMSS Information Notices2. List of Recently issued NRC Information NoticesDOCUMENT NAME: 96-35.INTo receive a copy of this document, Indicate In the box: C' = Copy without attachment/enclosure *E' -Copy with attachmentjendosure N |
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| ===Attachments:===
| | * No copy* See previous concurrenceOFFICE IIMAB* [ClIMAB* [C Tech Editor* l IMOB* [C IMNS* I C,NAME IDBroaddus* LCamper lEKraus _KRamsey jDCof'DATE 14/17/96 5/28/96 4/01/96 5/31/96 6/4 96 11OFFICIAL RECORD COPY |
| 1. List of Recently issued NMSS Information Notices2. List of Recently issued NRC Information NoticesDOCUMENT NAME: A:\IRADIATR.FINTo receive a copy of this docunent, Indicate hI the box: 'C Copy without attachmentlenclosure WE- = Copy with attachmentlenclosure ONE copY* See previous concurrence aOFFICE IMAB I INAB 15 /HTech Editor I IMOB IMN hNAME DBroaddus* LCam er' 1EKraus* KRamse Kmfl CoDATE 4/17/96 L/46/96 14/01/96 5-13j /96 /OFFICIAL RECORD COPY IN 96-XXMay XX, 1996 Users who are not aware of the required training for their unit, or who wishto receive information concerning training in general, should consult theirlicense, licensing authority, or the manufacturer of the unit. RegulatoryGuide 10.9, provides additional guidance in this area and may assist personswho wish to develop a training and maintenance program. Users who wish toreceive additional information concerning recommended maintenance for theirunit should contact the manufacturer of the unit. In addition, third-partyservice companies may also be available for training and maintenance servicesfor these types of irradiators.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Douglas Broaddus, NMSS301-415-5847Anthony Kirkwood, RI610-337-5050
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| | j;IN 96-XXMay XX, 1996 IN 96-XXMay XX, 1996 KUJ KUAttachment 1IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation ' Date ofNotice No. Subject Issuance Issued to96-33Erroneous Data from Defec-tive Thermocouple Resultsin a Fire05/224/96All material and fuel cyclelicensees that monitor tem-perature with thermocouples96-2896-2196-2096-18Suggested Guidance Relat-ing to Development andImplementation of Correc-tive ActionSafety Concerns Relatedto the Design of the DoorInterlock Circuit onNucletron High-Dose Rateand Pulsed Dose RateRemote Afterloading Brachy-therapy DevicesDemonstration of Associ-ated Equipment Compliancewith 10 CFR 34.20Compliance With 10 CFRPart 20 for AirborneThoriumIncident ReportingRequirements forRadiography Licensees10 CFR 34.20; FinalEffective DateHandling UncontainedYellowcake Outside of aFacility Processing CircuitRecent Incidents InvolvingPotential Loss of Controlof Licensed Material05/01/9604/10/9604/04/9603/25/9601/10/9612/18/9512/6/9510/27/95All material and fuel cyclelicenseesAll NRC Medical Licenseesauthorized to use brachy-therapy sources in high-and pulsed-dose-rate remoteAll industrial radiographylicensees and radiographyequipment manufacturersAll material licenseesauthorized to possess anduse thorium in unsealed formAll Radiography Licenseesand Manufacturers ofRadiography EquipmentIndustrial RadiographyLicensees.All Uranium RecoveryLicensees.All material and fuel cyclelicensees.96-0495-5895-5595-51 K> -iKJAttachment 2IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-3496-3396-3296-3196-30Hydrogen Gas Ignitionduring Closure Weldingof a VSC-24 Multi-AssemblySealed BasketErroneous Data FromDefective ThermocoupleResults in a FireImplementation of 10 CFR50.55a(g)(6)(ii)(A),"Augmented Examinationof Reactor Vessel"Cross-Tied Safety Injec-tion AccumulatorsInaccuracy of DiagnosticEquipment for Motor-Operated Butterfly ValvesRequirements in 10 CFRPart 21 for Reporting andEvaluating Software ErrorsSuggested Guidance Relatingto Development and Imple-mentation of CorrectiveActionPotential Clogging of HighPressure Safety InjectionThrottle Valves DuringRecirculationRecent Problems with Over-head CranesTransversing In-Core ProbeOverwithdrawn at LaSalleCounty Station, Unit 105/31/9605/24/9606/05/9605/22/9605/21/9605/20/9605/01/9605/01/9604/30/9604/30/96All holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicensees that monitor tem-perature with thermocouplesAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicenseesAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactors96-2996-2896-2796-2696-25OL -Operating LicenseCP -Construction Permit |
| 1. List of Recently issued NMSS Information Notices2. List of Recently issued NRC Information NoticesDOCUMENT NAME: A:\IRADIATR.FINTo receiv a copy of this document, Indicate In the box: C' = Copy without attachmentlenclosure 'E' = Copy with aftachment/enclosure *'N -No copylOFFICE IMAB [ IMAB LJTech Editor LAL IMOB LJIMNSINAME DBroaddus LCamper EKraus wa KRamsey DCoolDMTE 4//f/96 4/ /96 4/W /96 4/ /96 4/ /96OFFICIAL RECORD COPY KUJ KUAttachment 1IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation ' Date ofNotice No. Subject Issuance Issued to96-33Erroneous Data from Defec-tive Thermocouple Resultsin a Fire05/224/96All material and fuel cyclelicensees that monitor tem-perature with thermocouples96-2896-2196-2096-18Suggested Guidance Relat-ing to Development andImplementation of Correc-tive ActionSafety Concerns Relatedto the Design of the DoorInterlock Circuit onNucletron High-Dose Rateand Pulsed Dose RateRemote Afterloading Brachy-therapy DevicesDemonstration of Associ-ated Equipment Compliancewith 10 CFR 34.20Compliance With 10 CFRPart 20 for AirborneThoriumIncident ReportingRequirements forRadiography Licensees10 CFR 34.20; FinalEffective DateHandling UncontainedYellowcake Outside of aFacility Processing CircuitRecent Incidents InvolvingPotential Loss of Controlof Licensed Material05/01/9604/10/9604/04/9603/25/9601/10/9612/18/9512/6/9510/27/95All material and fuel cyclelicenseesAll NRC Medical Licenseesauthorized to use brachy-therapy sources in high-and pulsed-dose-rate remoteAll industrial radiographylicensees and radiographyequipment manufacturersAll material licenseesauthorized to possess anduse thorium in unsealed formAll Radiography Licenseesand Manufacturers ofRadiography EquipmentIndustrial RadiographyLicensees.All Uranium RecoveryLicensees.All material and fuel cyclelicensees.96-0495-5895-5595-51 K> -iKJAttachment 2IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-3496-3396-3296-3196-30Hydrogen Gas Ignitionduring Closure Weldingof a VSC-24 Multi-AssemblySealed BasketErroneous Data FromDefective ThermocoupleResults in a FireImplementation of 10 CFR50.55a(g)(6)(ii)(A),"Augmented Examinationof Reactor Vessel"Cross-Tied Safety Injec-tion AccumulatorsInaccuracy of DiagnosticEquipment for Motor-Operated Butterfly ValvesRequirements in 10 CFRPart 21 for Reporting andEvaluating Software ErrorsSuggested Guidance Relatingto Development and Imple-mentation of CorrectiveActionPotential Clogging of HighPressure Safety InjectionThrottle Valves DuringRecirculationRecent Problems with Over-head CranesTransversing In-Core ProbeOverwithdrawn at LaSalleCounty Station, Unit 105/31/9605/24/9606/05/9605/22/9605/21/9605/20/9605/01/9605/01/9604/30/9604/30/96All holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicensees that monitor tem-perature with thermocouplesAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicenseesAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactors96-2996-2896-2796-2696-25OL -Operating LicenseCP -Construction Permit}}
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Failure of Safety Systems on Self-Shielded Irradiators Because of Inadequate Maintenance and TrainingML031060046 |
Person / Time |
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Site: |
Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000442, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant ![Entergy icon.png](/w/images/7/79/Entergy_icon.png) |
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Issue date: |
06/11/1996 |
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From: |
Cool D A NRC/NMSS/IMNS |
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To: |
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References |
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IN-96-035, NUDOCS 9606060078 |
Download: ML031060046 (8) |
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Category:NRC Information Notice
MONTHYEARInformation Notice 2020-02, Flex Diesel Generator Operational Challenges2020-09-15015 September 2020 Flex Diesel Generator Operational Challenges ML20225A0322020-09-0303 September 2020 NRC Choice Letter to NAC International with Attached Safety Inspection Report, IR 0721015/2020201, February 24-27, 2020 and July 22, 2020, Inspection of NAC International in Norcross, Georgia Information Notice 2012-09, PWROG-16043-NP-A, Revision 2, PWROG Program to Address NRC Information Notice 2012-09: Irradiation Effects on Fuel Assembly Spacer Grid Crush Strength for Westinghouse and CE PWR Fuel Designs.2019-11-30030 November 2019 PWROG-16043-NP-A, Revision 2, PWROG Program to Address NRC Information Notice 2012-09: Irradiation Effects on Fuel Assembly Spacer Grid Crush Strength for Westinghouse and CE PWR Fuel Designs. Information Notice 2011-20, NRC060 - NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction (Nov. 18, 2011)2019-07-24024 July 2019 NRC060 - NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction (Nov. 18, 2011) ML19196A2452019-07-15015 July 2019 Public Notice - Sequoyah Nuclear Plant, Unit 2 - Exigent Amendment to Facility Operating License Information Notice 2019-01, Inadequate Evaluation of Temporary Alterations2019-03-12012 March 2019 Inadequate Evaluation of Temporary Alterations ML16028A3082016-04-27027 April 2016 NRC Information Notice; IN 2016-05: Operating Experience Regarding Complications From a Loss of Instrumentation Air Information Notice 2015-05, Inoperability of Auxiliary and Emergency Feedwater Auto Start Circuits on Loss of Main Feedwater Pumps2015-05-12012 May 2015 Inoperability of Auxiliary and Emergency Feedwater Auto Start Circuits on Loss of Main Feedwater Pumps Information Notice 2015-05, Inoperability Of Auxiliary And Emergency Feedwater Auto Start Circuits On Loss Of Main Feedwater Pumps2015-05-12012 May 2015 Inoperability Of Auxiliary And Emergency Feedwater Auto Start Circuits On Loss Of Main Feedwater Pumps Information Notice 2013-20, OFFICIAL EXHIBIT - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143)2013-10-0303 October 2013 OFFICIAL EXHIBIT - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143) Information Notice 2013-20, Official Exhibit - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143)2013-10-0303 October 2013 Official Exhibit - NYS000538-00-BD01 - NRC Information Notice 2013-20: Steam Generator Channel Head and Tubesheet Degradation (October 3, 2013) (ML13204A143) Information Notice 2013-11, OFFICIAL EXHIBIT - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013)2013-07-0303 July 2013 OFFICIAL EXHIBIT - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013) Information Notice 2013-11, Official Exhibit - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013)2013-07-0303 July 2013 Official Exhibit - NYS000551-00-BD01 - NRC Information Notice 2013-11: Crack-Like Indication at Dents/Dings and in the Freespan Region of Thermally Treated Alloy 600 Steam Generator Tubes (July 3, 2013) Information Notice 2010-12, Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Contain2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2010-12, Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Con2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend and/or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2010-12, Intervenors' Fifth Motion to Amend And/Or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notic2012-08-17017 August 2012 Intervenors' Fifth Motion to Amend And/Or Supplement Proposed Contention No. 5 (Shield Building Cracking). Appendix VI: NRC FOIA Responses (B-51 Through B-53); Turkey Point Event Report; NRC Information Notice 2010-12: Containment Liner Cor Information Notice 2012-13, Boraflex Degradation Surveillance Programs and Corrective Actions in the Spent Fuel Pool2012-08-10010 August 2012 Boraflex Degradation Surveillance Programs and Corrective Actions in the Spent Fuel Pool Information Notice 2012-13, Boraflex Degradation Surveillance Programs And Corrective Actions In The Spent Fuel Pool2012-08-10010 August 2012 Boraflex Degradation Surveillance Programs And Corrective Actions In The Spent Fuel Pool Information Notice 2012-11, Age Related Capacitor Degradation2012-07-23023 July 2012 Age Related Capacitor Degradation ML12031A0132012-02-0606 February 2012 U.S. Nuclear Regulatory Commission Investigation Report No. 2-2010-058, Cpn International, Inc Information Notice 2011-19, Licensee Event Reports Containing Information Pertaining to Defects to Basic Components2011-09-26026 September 2011 Licensee Event Reports Containing Information Pertaining to Defects to Basic Components Information Notice 2011-15, Steel Containment Degradation and Associated License Renewal Aging Management Issues2011-08-0101 August 2011 Steel Containment Degradation and Associated License Renewal Aging Management Issues Information Notice 2011-17, Calculation Methodologies for Operability Determinations of Gas Voids in Nuclear Power Plant Piping2011-07-26026 July 2011 Calculation Methodologies for Operability Determinations of Gas Voids in Nuclear Power Plant Piping Information Notice 2011-13, Official Exhibit - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13)2011-06-29029 June 2011 Official Exhibit - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) Information Notice 2011-13, Official Exhibit - Nys000329-00-Bd01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (Nrc in 2011-13)2011-06-29029 June 2011 Official Exhibit - Nys000329-00-Bd01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (Nrc in 2011-13) Information Notice 2011-13, OFFICIAL EXHIBIT - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13)2011-06-29029 June 2011 OFFICIAL EXHIBIT - NYS000329-00-BD01 - NRC Information Notice 2011-13, Control Rod Blade Cracking Resulting in Reduced Design Lifetime (Jun 29, 2011) (NRC in 2011-13) Information Notice 2011-04, IN: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 IN: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2011-04, In: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 In: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2011-04, in: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors2011-02-23023 February 2011 in: Contaminants and Stagnant Conditions Affecting Stress Corrosion Cracking in Stainless Steel Piping in Pressurized Water Reactors Information Notice 2010-26, New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-2010-12-30030 December 2010 New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-19 Information Notice 2010-26, New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review2010-12-30030 December 2010 New England Coalition'S Motion for Leave to Reply to NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 and Entergy'S Response to the Supplement to Nec'S Petition for Commission Review of LBP-10-19 Information Notice 2010-26, 2010/12/21-NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-262010-12-21021 December 2010 2010/12/21-NRC Staff'S Objection to Nec'S Notification of Information Notice 2010-26 ML13066A1872009-12-16016 December 2009 Draft NRC Information Notice 2009-xx - Underestimate of Dam Failure Frequency Used in Probabilistic Risk Assessments ML1007804482009-11-23023 November 2009 Email from Peter Bamford, NRR to Pamela Cowan, Exelon on TMI Contamination Control Event Information Notice 2009-11, NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-112009-07-0707 July 2009 NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-11 Information Notice 2009-10, Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10)2009-07-0707 July 2009 Official Exhibit - NYS000019-00-BD01- NRC Information Notice 2009-10, Transformers Failures - Recent Operating Experience (Jul. 7, 2009) (NRC in 2009-10) Information Notice 2009-09, Improper Flow Controller Settings Renders Injection Systems Inoperable and Surveillance Did Not Identify2009-06-19019 June 2009 Improper Flow Controller Settings Renders Injection Systems Inoperable and Surveillance Did Not Identify Information Notice 2008-12, Reactor Trip Due to Off-Site Power Fluctuation2008-07-0707 July 2008 Reactor Trip Due to Off-Site Power Fluctuation Information Notice 2008-11, Service Water System Degradation at Brunswicksteam Electric Plant Unit 12008-06-18018 June 2008 Service Water System Degradation at Brunswicksteam Electric Plant Unit 1 Information Notice 2008-04, Counterfeit Parts Supplied to Nuclear Power Plants2008-04-0707 April 2008 Counterfeit Parts Supplied to Nuclear Power Plants Information Notice 1991-09, Counterfeiting of Crane Valves2007-09-25025 September 2007 Counterfeiting of Crane Valves Information Notice 2007-28, Potential Common Cause Vulnerabilities in Essential Service Water Systems Due to Inadequate Chemistry Controls2007-09-19019 September 2007 Potential Common Cause Vulnerabilities in Essential Service Water Systems Due to Inadequate Chemistry Controls Information Notice 2007-29, Temporary Scaffolding Affects Operability of Safety-Related Equipment2007-09-17017 September 2007 Temporary Scaffolding Affects Operability of Safety-Related Equipment Information Notice 2007-14, Loss of Offsite Power and Dual-Unit Trip at Catawba Nuclear Generating Station2007-03-30030 March 2007 Loss of Offsite Power and Dual-Unit Trip at Catawba Nuclear Generating Station Information Notice 2007-06, Potential Common Cause Vulnerabilities in Essential Service Water Systems2007-02-0909 February 2007 Potential Common Cause Vulnerabilities in Essential Service Water Systems Information Notice 2007-05, Vertical Deep Draft Pump Shaft and Coupling Failures2007-02-0909 February 2007 Vertical Deep Draft Pump Shaft and Coupling Failures Information Notice 2006-31, Inadequate Fault Interrupting Rating of Breakers2006-12-26026 December 2006 Inadequate Fault Interrupting Rating of Breakers Information Notice 2006-29, Potential Common Cause Failure of Motor-operated Valves as a Result of Stem Nut Wear2006-12-14014 December 2006 Potential Common Cause Failure of Motor-operated Valves as a Result of Stem Nut Wear Information Notice 2006-29, Potential Common Cause Failure of Motor-operated Valves As a Result of Stem Nut Wear2006-12-14014 December 2006 Potential Common Cause Failure of Motor-operated Valves As a Result of Stem Nut Wear Information Notice 2006-13, E-mail from M. Mclaughlin on NRC, Regarding NRC Information Notice 2006-13: Groundwater Contamination2006-07-13013 July 2006 E-mail from M. Mclaughlin on NRC, Regarding NRC Information Notice 2006-13: Groundwater Contamination 2020-09-03 The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Three Mile Island]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:05000442]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] </code>.
[Table view]The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Three Mile Island]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:05000442]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] </code>. |
UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555June 11, 1996NRC INFORMATION NOTICE 96-35: FAILURE OF SAFETY SYSTEMS ON SELF-SHIELDEDIRRADIATORS BECAUSE OF INADEQUATE MAINTENANCEAND TRAINING
Addressees
All U.S. Nuclear Regulatory Commission irradiator licensees and vendors.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice (IN) to alert addressees to two incidents where safety interlocks onself-shielded irradiators (Category I) failed to prevent inadvertent exposure.The causes of these exposures stemmed from a lack of appropriate maintenanceand/or worker training. The incidents include a broken spring -- possiblycausing malfunction of the safety interlock -- and a worker who intentionallybypassed a safety interlock. It is expected that recipients will review theinformation for applicability to their facilities and consider actions, asappropriate, to avoid similar problems. However, suggestions contained inthis information notice are not NRC requirements; therefore, no specificaction nor written response is required.
Description of Circumstances
The first incident occurred when an operator may have been able to open theshielded door of an irradiator with the sources in the exposed position.After irradiation of several pocket dosimeters, the operator opened theshielded door of the irradiator to retrieve the dosimeters, but did notperform a radiation survey, as required by the facility's internal procedures,before opening the door. Twice, the operator placed one hand inside theirradiator to retrieve the dosimeters. Subsequently, the operator observedthat the unit timer continued to count, indicating that the sources remainedin the exposed position. The operator checked his personal pocket dosimeter,but did not note an unusual reading. However, the operator did not report theincident until questioned by the radiation safety officer, who had noted anunusually high dosimetry report of 3.55 millisievert (355 mrem) deep doseequivalent for the worker. The dose to the right hand was calculated to be amaximum of 12.5 millisievert (1.25 rem).The design of the irradiator includes two interconnected interlock systems,intended to prevent unshielded exposure of the sources. These include a doorinterlock system -- designed to allow opening of the shielded door only afterthe sources are placed in the fully shielded position -- and a source exposure-.interlock system -- designed to secure the sources in the fully shieldedtDR FE E NO r/C9 03 ?C 0t, II
kk JIIN 96-35June 11, 1996 position whenever the shielded door is open or unlocked. The manufacturer ofthe irradiator indicated that under normal operations, either systemindividually wouldiprevent inadvertent access to the unshielded sources.Following the incident, the manufacturer of the irradiator was requested toperform an onsite inspection of the irradiator and facilities. During theinspection, the manufacturer noted:(1) the irradiator was located in an area that was not climate-controlled;(2) internal components of the irradiator were in a degraded state;(3) maintenance of the irradiator had last been performed approximately10 years ago; and(4) a return spring, integral to the source exposure safety interlocksystem, was broken. The manufacturer indicated that the lack ofenvironmental control may have accelerated the degradation of theinternal components of the irradiator, and that the lack of periodicmaintenance of the irradiator may have contributed to the failure ofthe return spring.The broken return spring may have caused the source securing mechanism of thesource exposure interlock system to malfunction, possibly allowing exposure ofthe sources after the shielded door was unlocked and opened. However, duringthe post-incident investigation, neither the manufacturer nor the licenseewere able to identify a failed component of either interlock system that couldhave allowed the shielded door to be opened with the sources in the exposedposition. The manufacturer indicated that the design of the source exposuremechanism -- the operator must manually move the sources from the shielded tothe exposed position with a lever -- would have provided the operator with apositive indication of source position even if the interlock systems failed.Source position would have been further provided by a series of green and redsource position lights on the irradiator.The operator's actions indicate either a lack of training on the properfunctioning and use of the irradiator, a lack of understanding of the trainingprovided, and/or a disregard for following the established operating andsafety procedures. The operator indicated that the timer continued to countwhen the shielded door was opened. However, the manufacturer reported thatthe timer automatically activates whenever the source lever is manually movedto one of the two source exposed positions and the lever is fully engaged inthe source slot, and stops counting as soon as the lever is moved from thefully engaged position. The fact that the timer continued to count indicatesthat the operator had not moved the sources from the fully exposed and engagedposition. The licensee reported that the operator had been trained in theoperation of the irradiator and was listed as an authorized user, but that theirradiator was used infrequently and that this was only the operator's seconduse of the irradiator since being trained.The second incident occurred when a maintenance worker preparing to performmaintenance on an irradiator bypassed the irradiator door interlock system toobserve movement of the inner irradiation chamber. The maintenance was being
K>IN 96-35June 11, 1996 performed to correct previous maintenance that resulted in the irradiator notfunctioning properly. The maintenance worker was unaware that, although thesources remained shielded during movement of the irradiation chamber from theload to irradiate position, high levels of radiation scatter would be present.The maintenance worker, upon hearing the in-room monitor alarm, immediatelyreturned the radiation chamber to the 'load' position (maximum shielding).Although the maintenance worker was familiar with the operation of theirradiator and had been responsible for its maintenance for nearly 15 years,the worker apparently had not been given formal training on radiation safetyor the operation and maintenance of the irradiator. The maintenance workerwas not aware of the scatter radiation and assumed that since the sources werenot directly exposed, radiation from the sources would be contained within thedevice.During this incident, another worker, hired to perform contract maintenance onthe irradiator, was also in the room near the irradiator. Neither worker woredosimetry nor had any documented training in radiation safety. Therefore,their doses could only be calculated based on their recollection and wereestimated to both be approximately 4 microsievert (0.4 mrem) whole body.DiscussionAlthough neither incident resulted in doses in excess of regulatory limits,the doses received in both incidents were unnecessary and possibly could havebeen avoided with proper training and routine equipment maintenance. Asimilar incident in 1984, where a door interlock failed, resulted in theoperator being exposed to 222 terabequerel (6000 curies) of cesium-137.The first incident clearly demonstrates the need to perform appropriatemaintenance on these types of units. Even though these units are designedwith interlocks and safety features intended to prevent inadvertent exposures,the components of these systems depend on adequate maintenance to functionproperly. Failure to properly maintain these systems and provide appropriatetraining could result in unnecessary exposures. Manufacturers of these typesof irradiators frequently provide initial and periodic training on theoperation of their units and, in some cases, training on other manufacturers'units, as well. Initial training is typically a condition of the license and,therefore, must be provided to all irradiator users and maintenance personnel.Periodic refresher training is also beneficial as a reminder for workingsafely around the irradiator and provides for a means to receive ordisseminate additional or updated information.In addition, most manufacturers have a recommended schedule of maintenanceand/or recommended preventative/periodic maintenance that should be performed.Users of these types of irradiators should evaluate their usage to determinethe applicability of the recommended maintenance to their situation and usage.Users who operate their unit more than usual or who use their units underharsh conditions should consider the need for stepped-up maintenance or
'-> IN 96-35June 11, 1996 shortened maintenance intervals. In addition, each manufacturer's recommendedmaintenance may vary according to the specific unit or type of use.Therefore, personis performing maintenance on their unit may require specificmaintenance training for their unit.Users who are not aware of the required training for their unit, or who wishto receive information concerning training in general, should consult theirlicense, licensing authority, or the manufacturer of the unit. RegulatoryGuide 10.9, provides additional guidance in this area and may assist personswho wish to develop a training and maintenance program. Users who wish toreceive additional information concerning recommended maintenance for theirunit should contact the manufacturer of the unit. In addition, third-partyservice companies may also be available for training and maintenance servicesfor these types of irradiators.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.I3W¶flstn8by9WWstIADonald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Douglas Broaddus, NMSS(301) 415-5847Internet:dab~nrc.govAnthony Kirkwood, NMSS(301) 415-6140Internet:ask~nrc.govAttachments:1. List of Recently issued NMSS Information Notices2. List of Recently issued NRC Information NoticesDOCUMENT NAME: 96-35.INTo receive a copy of this document, Indicate In the box: C' = Copy without attachment/enclosure *E' -Copy with attachmentjendosure N
- No copy* See previous concurrenceOFFICE IIMAB* [ClIMAB* [C Tech Editor* l IMOB* [C IMNS* I C,NAME IDBroaddus* LCamper lEKraus _KRamsey jDCof'DATE 14/17/96 5/28/96 4/01/96 5/31/96 6/4 96 11OFFICIAL RECORD COPY
j;IN 96-XXMay XX, 1996 IN 96-XXMay XX, 1996 KUJ KUAttachment 1IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation ' Date ofNotice No. Subject Issuance Issued to96-33Erroneous Data from Defec-tive Thermocouple Resultsin a Fire05/224/96All material and fuel cyclelicensees that monitor tem-perature with thermocouples96-2896-2196-2096-18Suggested Guidance Relat-ing to Development andImplementation of Correc-tive ActionSafety Concerns Relatedto the Design of the DoorInterlock Circuit onNucletron High-Dose Rateand Pulsed Dose RateRemote Afterloading Brachy-therapy DevicesDemonstration of Associ-ated Equipment Compliancewith 10 CFR 34.20Compliance With 10 CFRPart 20 for AirborneThoriumIncident ReportingRequirements forRadiography Licensees10 CFR 34.20; FinalEffective DateHandling UncontainedYellowcake Outside of aFacility Processing CircuitRecent Incidents InvolvingPotential Loss of Controlof Licensed Material05/01/9604/10/9604/04/9603/25/9601/10/9612/18/9512/6/9510/27/95All material and fuel cyclelicenseesAll NRC Medical Licenseesauthorized to use brachy-therapy sources in high-and pulsed-dose-rate remoteAll industrial radiographylicensees and radiographyequipment manufacturersAll material licenseesauthorized to possess anduse thorium in unsealed formAll Radiography Licenseesand Manufacturers ofRadiography EquipmentIndustrial RadiographyLicensees.All Uranium RecoveryLicensees.All material and fuel cyclelicensees.96-0495-5895-5595-51 K> -iKJAttachment 2IN 96-35June 11, 1996 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-3496-3396-3296-3196-30Hydrogen Gas Ignitionduring Closure Weldingof a VSC-24 Multi-AssemblySealed BasketErroneous Data FromDefective ThermocoupleResults in a FireImplementation of 10 CFR50.55a(g)(6)(ii)(A),"Augmented Examinationof Reactor Vessel"Cross-Tied Safety Injec-tion AccumulatorsInaccuracy of DiagnosticEquipment for Motor-Operated Butterfly ValvesRequirements in 10 CFRPart 21 for Reporting andEvaluating Software ErrorsSuggested Guidance Relatingto Development and Imple-mentation of CorrectiveActionPotential Clogging of HighPressure Safety InjectionThrottle Valves DuringRecirculationRecent Problems with Over-head CranesTransversing In-Core ProbeOverwithdrawn at LaSalleCounty Station, Unit 105/31/9605/24/9606/05/9605/22/9605/21/9605/20/9605/01/9605/01/9604/30/9604/30/96All holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicensees that monitor tem-perature with thermocouplesAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicenseesAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactors96-2996-2896-2796-2696-25OL -Operating LicenseCP -Construction Permit
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list | - Information Notice 1996-01, Potential For High Post-Accident Closed-Cycle Cooling Water Temperatures to Disable Equipment Important to Safety (3 January 1996)
- Information Notice 1996-01, Potential for High Post-Accident Closed-Cycle Cooling Water Temperatures to Disable Equipment Important to Safety (3 January 1996)
- Information Notice 1996-02, Inoperability of Power-Operated Relief Valves Masked by Downstream Indications During Testing (5 January 1996, Topic: Stroke time)
- Information Notice 1996-03, Main Steam Safety Valve Setpoint Variation as a Result of Thermal Effects (5 January 1996)
- Information Notice 1996-03, Main Steam Safety Valve Setpoint Variation As a Result of Thermal Effects (5 January 1996)
- Information Notice 1996-04, Incident Reporting Requirements for Radiography Licensees (10 January 1996, Topic: Brachytherapy, Overexposure, Depleted uranium)
- Information Notice 1996-05, Partial Bypass of Shutdown Cooling Flow from Reactor Vessel (18 January 1996, Topic: Reactor Vessel Water Level)
- Information Notice 1996-06, Design & Testing Deficiencies of Tornado Dampers at Nuclear Power Plants (25 January 1996)
- Information Notice 1996-07, Slow Five Percent Scram Insertion Times Caused by Viton Diaphragms in Scram Solenoid Pilot Valves (26 January 1996)
- Information Notice 1996-08, Thermally Induced Pressure Locking of a High Pressure Coolant Injection Gate Valve (5 February 1996, Topic: Anchor Darling, Cold shutdown justification)
- Information Notice 1996-09, Damage in Foreign Steam Generator Internals (12 February 1996, Topic: Earthquake)
- Information Notice 1996-10, Potential Blockage by Debris of Safety System Piping Which Is Not Used During Normal Operation or Tested During Surveillances (13 February 1996)
- Information Notice 1996-10, Potential Blockage by Debris of Safety System Piping Which is Not Used During Normal Operation or Tested During Surveillances (13 February 1996)
- Information Notice 1996-11, Ingress of Demineralizer Resins Increases Potential For Stress Corrosion Cracking of Control Rod Drive Mechanism Penetrations (14 February 1996)
- Information Notice 1996-11, Ingress of Demineralizer Resins Increases Potential for Stress Corrosion Cracking of Control Rod Drive Mechanism Penetrations (14 February 1996)
- Information Notice 1996-12, Control Rod Insertion Problems (15 February 1996)
- Information Notice 1996-13, Potential Containment Leak Paths Through Hydrogen Analysis (26 February 1996, Topic: Stress corrosion cracking, Integrated leak rate test)
- Information Notice 1996-14, Degradation of Radwaste Facility Equipment at Millstone Nuclear Power Station, Unit 1 (1 March 1996)
- Information Notice 1996-15, Unexpected Plant Performance During Performance of New Surveillance (8 March 1996)
- Information Notice 1996-16, BWR Operation with Indicated Flow Less than Natural Circulation (14 March 1996, Topic: Stress corrosion cracking)
- Information Notice 1996-17, Reactor Operation Inconsistent with the Updated Final Safety Analysis Report (18 March 1996)
- Information Notice 1996-18, Compliance with 10 CFR Part 20 for Airborne Thorium (25 March 1996, Topic: Stress corrosion cracking, Brachytherapy)
- Information Notice 1996-19, Failure of Tone Alert Radios to Activate When Receiving a Shortened Activation Signal (2 April 1996, Topic: Tone Alert Radio, Siren)
- Information Notice 1996-20, Demonstration of Associated Equipment Compliance with 10 CFR 34.20 (4 April 1996, Topic: Brachytherapy)
- Information Notice 1996-21, Safety Concerns Related to the Design of the Door Interlock Circuit on Nucletron High-Dose Rate and Pulsed Dose Rate Remote Afterloading Brachytherapy Devices (10 April 1996, Topic: Brachytherapy)
- Information Notice 1996-22, Improper Equipment Settings Due to Use of Nontemperature-Compensated Test Equipment (11 April 1996, Topic: Brachytherapy)
- Information Notice 1996-23, Fires in Emergency Diesel Generator Exciters During Operation Following Undetected Fuse Blowing (22 April 1996, Topic: Brachytherapy, Overspeed trip)
- Information Notice 1996-24, Preconditioning of Molded-Case Circuit Breakers Before Surveillance Testing (25 April 1996, Topic: Brachytherapy)
- Information Notice 1996-25, Traversing In-Core Probe Overwithdrawn at Lasalle County Station, Unit 1 (30 April 1996, Topic: Brachytherapy)
- Information Notice 1996-26, Recent Problems with Overhead Cranes (30 April 1996, Topic: Brachytherapy)
- Information Notice 1996-26, Recent Problems With Overhead Cranes (30 April 1996)
- Information Notice 1996-27, Potential Clogging of High Pressure Safety Injection Throttle Valves During Recirculation (1 May 1996, Topic: Brachytherapy)
- Information Notice 1996-28, Suggested Guidance Relating to Development and Implementation of Corrective Action (1 May 1996, Topic: Brachytherapy)
- Information Notice 1996-29, Requirements in 10 CFR Part 21 for Reporting and Evaluating Software Errors (20 May 1996, Topic: Brachytherapy)
- Information Notice 1996-30, Inaccuracy of Diagnostic Equipment for Motor-Operated Butterfly Valves (21 May 1996)
- Information Notice 1996-31, Cross-Tied Safety Injection Accumulators (22 May 1996)
- Information Notice 1996-32, Implementation of 10 CFR 50.55a(g) (6) (II) (A), Augmented Examination of Reactor Vessel (5 June 1996, Topic: Non-Destructive Examination)
- Information Notice 1996-32, Implementation of 10 CFR 50.55a(g) (6) (ii) (A), Augmented Examination of Reactor Vessel (5 June 1996, Topic: Non-Destructive Examination)
- Information Notice 1996-33, Erroneous Data From Defective Thermocouple Results in a Fire (24 May 1996, Topic: Reverse polarity)
- Information Notice 1996-33, Erroneous Data from Defective Thermocouple Results in a Fire (24 May 1996, Topic: Reverse polarity)
- Information Notice 1996-34, Hydrogen Gas Ignition During Closure Welding of a VSC-24 Multi-Assembly Sealed Basket (31 May 1996)
- Information Notice 1996-35, Failure of Safety Systems on Self-Shielded Irradiators Because of Inadequate Maintenance and Training (11 June 1996)
- Information Notice 1996-36, Degradation of Cooling Water Systems Due to Icing (12 June 1996, Topic: High winds, Ultimate heat sink, Frazil ice)
- Information Notice 1996-37, Inaccurate Reactor Water Level Indication and Inadvertent Draindown During Shutdown (18 June 1996, Topic: Reactor Vessel Water Level)
- Information Notice 1996-38, Results of Steam Generator Tube Examinations (21 June 1996, Topic: Stress corrosion cracking)
- Information Notice 1996-39, Estimates of Decay Heat Using ANS 5.1 Decay Heat Standard May Vary Significantly (5 July 1996)
- Information Notice 1996-40, Defciencies in Material Dedication and Procurement Practices and in Audits of Vendors (7 October 1996, Topic: Coatings, Troxler Moisture Density Gauge)
- Information Notice 1996-41, Effects of a Decrease in Feedwater Temperature on Nuclear Instrumentation (26 July 1996, Topic: Feedwater Heater)
- Information Notice 1996-42, Unexpected Opening of Multiple Safety Relief Valves (5 August 1996, Topic: Reactor Vessel Water Level)
- Information Notice 1996-43, Failures of General Electric Magne-Blast Circuit Breakers (2 August 1996)
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