Information Notice 2002-31, Potentially Defective Uf6 Cylinder Valves (1-inch)
| ML030710026 | |
| Person / Time | |
|---|---|
| Issue date: | 03/24/2003 |
| Revision: | 0 |
| From: | Pierson R C NRC/NMSS/FCSS |
| To: | |
| References | |
| IN-02-031, Suppl 1 | |
| Download: ML030710026 (7) | |
UNITED STATES NUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555March 24, 2003NRC INFORMATION NOTICE 2002-31, SUPPLEMENT 1POTENTIALLY DEFECTIVE UF6 CYLINDER VALVES(1-INCH)
Addressees
All U.S. Nuclear Regulatory Commission (NRC) licensees authorized to possess and usesource material and/or special nuclear material for heating, emptying, filling, or shipping 30- and 48-inch cylinders of uranium hexafluoride (UF6).
Purpose
The NRC previously issued Information Notice 2002-31 to inform addressees about two safetyconcerns related to 1-inch UF6 cylinder valves manufactured by the Hunt Valve Company, Inc.,of Salem, Ohi The safety concerns were: (1) cracked packing nuts and; (2) the loss of material traceability and failure to conduct hardness testing of the valve stem Since then, the United States Enrichment Corporation (USEC) has conducted a series of tests to verify that the valves would perform their intended safety functio The NRC is issuing this supplement to inform addressees that, as a result of those tests, anumber of valves failed to meet the seat leakage performance requirement It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problem Suggestions contained in this information notice do not constitute new NRC requirements; therefore, no specific action or written response is required.
Description of Circumstances
USEC conducted a series of tests to determine whether the 1-inch UF6 cylinder valvesmanufactured by the Hunt Valve Company meet the critical characteristics specified in ANSI N 14.1, "American National Standard for Nuclear Materials - Uranium Hexafluoride - Packaging for Transport." One of the more important critical characteristics tested was seat leakag ANSI N 14.1 requires a 400 psig leak test with no leakage permitte USEC initially tested a sample size of 56 valves in its store Of those tested, one valve failed, and another possible failure has been referred to the ANSI N14.1 Committee for interpretatio The two valves in question came from one specific vendor lot of 100 valve USEC then proceeded to conduct additional seat leakage tests on all of the remaining valves inthe parent lo As a result of the testing conducted to date, USEC has identified 13 valve failures out of 210 valves teste Preliminary indications are that the failures are caused by bronze debris on the valve seat The jagged debris was apparently cut from the valve body bronze threads by the harder monel valve stem threads that were not adequately de-burred orML030710026 IN 2002-31, Sup 1 polishe An optical inspection of valves manufactured by other vendors and previouslymanufactured Hunt valves found significantly less debris present and a polished finis USEC polished the valve stems of several of the leaking valves and successfully retested them to the ANSI N14.1 test acceptance criteria.DiscussionAlthough the nonconforming valves identified thus far belong to one valve lot, the potentialnonconformance may extend to other lot During an inspection at Hunt Valve in 2001, the NRC identified an ineffective quality assurance progra It could not be determined how long the quality assurance problems had existe Consequently, the potential nonconforming problems have not been limited to any single Hunt valve lot at this time.As indicated in the original Information Notice, the 1-inch UF6 valves form part of the pressureboundary for Model No. 30B (30-inch diameter) cylinders that contain low-enriched uranium (up to 5 percent U235) and various 48-inch diameter cylinders containing enriched, natural anddepleted (tails) uraniu As such, the valves perform several safety functions as described in IN 2002-31 dated October 31, 200 In addition, packages shipped under an NRC Certificate of Compliance must conform to ANSI N1 Conformance to ANSI N14.1 is also required by Department of Transportation regulations (see 49 CFR 173.420).Related Generic CommunicationsInformation Notice No. 89-78: "Failure of Packing Nuts on One-Inch UraniumHexafluoride Cylinder Valves"Information Notice No. 97-24: "Failure of Packing Nuts on One-Inch UraniumHexafluoride Cylinder Valves"Information Notice No. 02-31: "Potentially Defective UF6 Cylinder Valves (1-inch)"This notice does not require any specific action or written respons If you have any questionsabout the information in this notice, please contact the technical contact listed below or the appropriate project manager in the NRC's Office of Nuclear Material Safety and Safeguards./RA/Robert C. Pierson, DirectorDivision of Fuel Cycle, Safety and Safeguards Office of Nuclear Material Safety and Safeguards
Technical Contact:
William Troskoski, NMSS(301) 415-8076 E-mail: wmt@nrc.gov
Attachments:
List of Recently Issued NRC Information Notices List of Recently Issued NMSS Information Notices IN 2002-31, Sup 1 polishe An optical inspection of valves manufactured by other vendors and previouslymanufactured Hunt valves found significantly less debris present and a polished finis USEC polished the valve stems of several of the leaking valves and successfully retested them to the ANSI N14.1 test acceptance criteria.DiscussionAlthough the nonconforming valves identified thus far belong to one valve lot, the potentialnonconformance may extend to other lot During an inspection at Hunt Valve in 2001, the NRC identified an ineffective quality assurance progra It could not be determined how long the quality assurance problems had existe Consequently, the potential nonconforming problems have not been limited to any single Hunt valve lot at this time.As indicated in the original Information Notice, the 1-inch UF6 valves form part of the pressureboundary for Model No. 30B (30-inch diameter) cylinders that contain low-enriched uranium (up to 5 percent U235) and various 48-inch diameter cylinders containing enriched, natural anddepleted (tails) uraniu As such, the valves perform several safety functions as described in IN 2002-31 dated October 31, 200 In addition, packages shipped under an NRC Certificate of Compliance must conform to ANSI N1 Conformance to ANSI N14.1 is also required by Department of Transportation regulations (see 49 CFR 173.420).Related Generic CommunicationsInformation Notice No. 89-78: "Failure of Packing Nuts on One-Inch UraniumHexafluoride Cylinder Valves"Information Notice No. 97-24: "Failure of Packing Nuts on One-Inch UraniumHexafluoride Cylinder Valves"Information Notice No. 02-31: "Potentially Defective UF6 Cylinder Valves (1-inch)"This notice does not require any specific action or written respons If you have any questionsabout the information in this notice, please contact the technical contact listed below or the appropriate project manager in the NRC's Office of Nuclear Material Safety and Safeguards./RA/Robert C. Pierson, DirectorDivision of Fuel Cycle, Safety and Safeguards Office of Nuclear Material Safety and Safeguards
Technical Contact:
William Troskoski, NMSS(301) 415-8076 E-mail: wmt@nrc.gov
Attachments:
List of Recently Issued NRC Information Notices List of Recently Issued NMSS Information NoticesML030710026*See previous concurrenceOfficeSPIB*Editor*SFPO*OI*SPIB*FCSSNAMEWTroskoskiEKrausWBrachMKFaheyMLeachRPiersonDATE3/7/033/10/033/7/033/10/033/11/033/24/03
______________________________________________________________________________________OL = Operating License CP = Construction PermitAttachment 1IN 2002-31, Sup 1 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICES_____________________________________________________________________________________InformationDate of Notice N SubjectIssuanceIssued to_____________________________________________________________________________________2003-08Potential Flooding ThroughUnsealed Concrete Floor Cracks06/25/2003All holders of operating licensesor construction permits for nuclear power reactors.2003-07Water in the Vent Header/ventLine Spherical Junctions06/24/2003All holders of operating licensesfor boiling water reactors (BWRs)
with a Mark I containment.2003-06Failure of Safety-relatedLinestarter Relays at San Onofre Nuclear Generating Station06/19/2003All holders of operating licensesor 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.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.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
______________________________________________________________________________________OL = Operating License CP = Construction PermitAttachment 2IN 2002-31, Sup 1 LIST OF RECENTLY ISSUEDNMSS INFORMATION NOTICES_____________________________________________________________________________________InformationDate of Notice N SubjectIssuanceIssued to
_____________________________________________________________________________________2002-36Incomplete or InaccurateInformation Provided to the Licensee and/or NRC By Any Contractor or Subcontractor Employee12/27/2002All materials and fuel cyclelicensees and certificate holders.2002-35Changes to 10 CFR Parts 71and 72 Quality Assurance Programs12/20/2002All holders of 10 CFR Part 71quality assurance program approvals and all 10 CFR Part 72 licensees and certificate holders2002-33Notification of PermanentInjunction Against Neutron Products Incorporated of Dickerson, Maryland11/21/2002All teletherapy and radiationprocessing licensees. 2002-31Potentially Defective UF6Cylinder Valves (1-inch)10/31/2002All licensees authorized topossess and use source material and/or special nuclear material for the heating, emptying, filling, or shipping of uranium hexafluoride (UF6) in 30- and 48-inchcylinders.2002-30Control and Surveillance ofPortable Gauges During Field Operations10/30/2002All NRC licensees authorized topossess, use, transport, and store portable gauges.2002-28Appointment of RadiationSafety Officers and Authorized Users Under 10 CFR Part 3509/27/2002All medical licensees.Note:NRC generic communications may be received in electronic format shortly after they are issued bysubscribing to the NRC listserver as follows:To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following command in themessage portion:subscribe gc-nrr firstname lastname