Information Notice 1987-29, Recent Safety-Related Incidents at Large Irradiators

Recent Safety-Related Incidents at Large Irradiators

ML031190114
Person / Time
Issue date:	06/26/1987
Revision:	0
From:	Cunningham R E NRC/NMSS/IMNS
To:
References
IN-87-029, NUDOCS 8706220303
Download: ML031190114 (6)

X, vtCAttachment 2IN 89-82December 7, 1989 UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D. C. 20555June 26, 1987NRC INFORMATION NOTICE NO. 87-29: RECENT SAFETY-RELATED INCIDENTS ATLARGE IRRADIATORS

Addressees

All NRC licensees authorized to possess and use sealed sources in largeirradiators.

Purpose

i--This notice is being issued to inform recipients of recent safety-relatedincidents at large irradiators, which could have been prevented by propermanagement aictions and attention to preventative maintenance programs. It:is suggested that recipients review this information and their proceduresand consider actions, if appropriate, to ensure both proper preventativemaintenance programs and proper management actions at their facilities.-However, suggestions contained In this Information Notice do not constituteNRC requirements; therefore, no specific action or written response is required.

Description of Circumstances

A description of each of six events is provided in Attachment 1. In summary,these events included:o hose failure resulting in a leak, failure to report the incident to NRC,and deliberate cover-up of this incident when NRC tried to investigate,leading to company fines and personnel probation;o intentional bypass of safety interlocks, resulting in'license suspensionand other enforcement actions by NRC;o improper pipe routing and inadequate piping material, which broke andcaused partial loss of pool water;o source unable to retract to its fully shielded position, due to a frozensolenoid valve;o a stuck source plaque, due to failure to promptly replace a frayed liftcable; ando a stuck source plaque, due to interference from the product carriers andshroud.8706220303 IN 87-29June 26, 1987 Discussion:These incidents illustrate a failure by management to assure that propersafety and maintenance procedures are followed. It is suggested that super-visory personnel, particularly the Radiation Protection Officer and maintenancepersonnel, be reminded of their responsibilities to assure safe operation attheir facilities. The incidents discussed in Attachment 1 demonstrate theimportance of:1. prompt reporting of incidents to the NRC, as required by regulations orlicense conditions2. safety training and periodic retraining of personnel3. not bypassing interlock systems or other safety systems4. attention to proper plumbing installation and use of appropriate pipingmaterial5. proper maintenance of cables, carrier systems, and other components that*could prevent radioactive sources from being retracted to a shieldedposition.No specific actions or written response is required by this InformationNotice. If you have any questions about this matter, please contact theRegional Administrator of the appropriate NRC regional office or this office.Richard E. Cunningham, DirectorDivision of Fuel Cycle, Medical,Academic, and Commercial Use SafetyOffice of Nuclear Material Safetyand Safeguards

Technical Contact:

Bruce Carrico, K1SS(301) 427-4280

Attachments:

1. Events That Occurred at Large Irradiator Facilities2. List of Recently Issued NRC Information NoticesAttachment 2IN 89-82December 7, 1989 Attachment IIN 87-29June 26, 1987EVENTS THAT OCCURRED AT LARGE IRRADIATOR FACILITIES1. While the licensee was attempting to decontaminate pool water because ofa leaking source, a hose on a filtration system ruptured. Contaminatedpool water was then pumped onto the facility floor and leaked outside intothe surrounding soil. The licensee failed to report the incident to NRC,and made deliberate efforts to prevent NRC's discovery of this incident."Subsequently, the licensee was indicted by a Federal Court. *A convictionresulted in a $35,000 fine for the company and two years probation for amanagement employee. Licensee failure to make required reports preventsthe HRC from performing its radiological health and safety function andfrom making a timely assessment of the nature and severity of an incident.2. A licensee deliberately bypassed the safety interlock systems. The NRCsubsequently learned that licensee personnel had willfully violatedrequirements, and that senior licensee management knew, or should haveknown, of these violations. When NRC attempted to inspect and investigatethese suspected violations, senior licensee management knowingly providedfalse information to the NRC. Subsequent enforcement action includedsuspension of the license.3. A water line fractured in the pool circulation system which resulted inthe loss of 5 feet of pool water. The line break led to a loss ofshielding water because the intake and outlet pipes were misalignedduring maintenance. The pipe break appears to have occurred becausethe pipe was made of polyvinyl chloride, designed for cold water, ratherthan for the heated water temperatures typical for the irradiator. Thepiping was replaced with polypropylene pipe.4. A night shift operator noticed that the travel time for the source toreach the fully unshielded position was excessive. After completingthe next phase of irradiation, the source would not retract to the fullyshielded position, even using emergency equipment. The operator discoveredthat the solenoid valve, that was supposed to retract the source to ashielded position, was frozen due to weather conditions. The valve wasin a room above the irradiator facility. The operator went there andturned on a room heater to thaw out the valve so that it would operate.The operator violated license requirements to (1) notify the RadiationSafety Officer (RSO) that the source had not returned to Its shieldedposition because of the frozen valve, and (2) obtain RSO permission toenter and heat the room housing the valve.5. A licensee had identified a frayed lift cable a few days previously, butinstead of immediately replacing the cable, the licensee decided to waitfor scheduled maintenance. The cable Jammed and froze the source plaquein a less than fully shielded position. Employees cut the cables and letthe source plaque free-fall into the pool. The incident could have beenprevented by replacing the frayed cable imuediately, and selecting cablematerial with fray-resistant qualities.Attachment 2IN 89-82December 7, 1989 6. A source plaque became stuck In the exposed position. Conveyors stopped,'.A :ojirce DOWN 'ight came on, but cell radiation levels remained high.Cable slack data indicated that the plaque was stuck about five and a halffeet down from its full-up position. The RSO attempted some raising andlowering maneuvers, but the plaque then stuck in a full-up position. TheRSO, able to run the product containers out of the cell, saw some weremisaligned on the carrier. The RSO notified a State Inspector, who arrivedin the afternoon. It was determined that the plaque cable was off its pulley.The bottom of a splice in the cable was resting on the lip of the tubeleading to the cell. After the cable was set on its pulley, the cable wasguided through the tube, and the plaque was lowered, until it caught again.--A borrowed radiation-resistant camera arrived the next morning. An adequateview of the plaque was obtained by midnight. Apparently the stationaryaluminum shroud between product containers and plaque had been deflectedand caught on the plaque frame. The plaque was carefully raised and droppedto break the Jam. On the second try, the plaque broke free and droppedinto the pool. Analysis revealed that a product container had probablytipped onto the shroud, causing interference with the plaque.This incident was apparently caused by inadequate design of the shroud.This led to the shroud deforming, which interfered with plaque motion.Inadequate maintenance contributed to the problem. The cable shouldhave been replaced instead of spliced. A few months later, the entiresource hoist mechanism failed and had to be replaced. This failure oc-*curred when the source plaque was submerged.Attachment 2IN 89-82December 7, 1989 -2 -

$ IAttachment 3IN 89-82December 7, 1989 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to89-7889-6089-4789-4689-3789-3589-3489-25Failure of Packing Nuts onOne-Inch Uranium HexafluorideCylinder ValvesMaintenance of TeletherapyUnitsPotential Problems withWorn or Distorted HoseClamps on Self-ContainedBreathing ApparatusConfidentiality ofExercise ScenariosProposed Amendments to 40CFR Part 61, Air EmissionStandards for RadionuclidesLoss and Theft of UnsecuredLicensed MaterialDisposal of AmericiumWel1-Logging SourcesUnauthorized Transfer ofOwnership or Control ofLicensed Activities11/22/8908/18/8905/18/8905/11/8904/04/8903/30/8903/30/8903/07/89All U.S. NRC licenseesauthorized to possessand use source materialand/or special nuclearmaterial for the heating,emptying, filling, orshipping of uraniumhexafluoride in 30- and48-inch diameter cylinders.All U.S. NRC MedicalTeletherapy Licensees.All holders of operatinglicenses or constructionpermits for nuclear powerreactors and fuelfacilities.All holders of licensesfor fuel cycle facilitiesand byproduct materiallicensees having anapproved emergencyresponse plan.All U.S. NRC licensees.All U.S. NRC byproduct,source and specialnuclear material licensees.All holders of U.S. NRCspecific licensesauthorizing well-loggingactivities.All NRC source, byproduct,and special nuclearmaterial licensee t .a 4Attachment 4IN 89-82December 7, 1989Page 1 of ILIST OF RECENTLY ISSUEDNRC INFORMATION NOTICES---e --001_____. < _InrormaliwNotice No.89-59,Supp. I899C189-8089-7989-56,Supp. 189-7889-7789-76SubjectSuppliers of PotentiallyMisrepresented FastenersInadequate Control afTemporary Modificationsto Safety-Related SystemsPotential for Wdater HanmreThermal Stratification, andSteam Sinding in High-Pressure Coolant InjectionPipingDegraded Coatings andCorrosion of SteelContainment VesselsQuestionable Certificationof Material Supplied tothe Defense Departmentby Nuclear SuppliersFailure of Packing Nutson One-Inch UraniumHexafluoride CylinderValvesDebris in ContainmentEmergency Sumps andIncorrect ScreenConfigurationsBiofouling Agent: Zebra1NusselDJAW OfIssuance12/6/8912/6/8912/1/8912/1/8911/22/89Issued toAll holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for LkRs.All holders of OLsor CPs for nuclearpower reactors.11/22/89 All NRC licenseesauthorized to possessand use source materialand/or special nuclearmaterial for the heating,emptying, filling, orshipping of uraniumhexafluoride In 30-and 48-inch diametercylinders.11/21/89 All holders of OLsor CPs for PURs.11/21/89 All holders of OLsor CPs for nuclearpower reactors.OL

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• Construction PermitUNITED STATESNUCLEAR REGULATORY COMMISSIONWASHINGTON, D.C. 20555OFFICIAL BUSINESSPENALTY FOR PRIVATE USE, 5300PIRST CLASS MAILIPOSTAGE & FEES PAIDUSNACPERMIT No. 0 p-U Sup SvCs -' -. 4A HVCS SVCS SECTOC 205551