ML073200086
| ML073200086 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Nine Mile Point, Palisades, Palo Verde, Indian Point, Harris, Point Beach, Grand Gulf, Cooper, Pilgrim, Arkansas Nuclear, Brunswick, Surry, North Anna, Vermont Yankee, Crystal River, Waterford, South Texas, Cook, Quad Cities, Fort Calhoun, FitzPatrick  |
| Issue date: | 11/09/2007 |
| From: | Curtin D Conval |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| 43776 | |
| Download: ML073200086 (4) | |
Text
1110912007 U.S. Nuclear Regulatory Commission Operations Center Event Report Paze I General Information or Other (PAR) Event# 43776 Rep Org: CONVAL INC Notification Date /Time: 11/09/2007 15:30 (EST)
Supplier: CONVAL INC Event Date/ Time: 11/09/2007 (EST)
Last Modification: 11/09/2007 Region: 1 Docket #:
City: SOMERS Agreement State: No County: License #:
State: CT NRC Notified by: DONALD CURTIN Notifications: MARIE MILLER R1 HQ Ops Officer: MARK ABRAMOVITZ MARK LESSER R2 Emergency Class: NON EMERGENCY MONTE PHILLIPS R3 10 CFR Section: BLAIR SPITZBERG R4 21.21 UNSPECIFIED PARAGRAPH VERN HODGE (EMAIL) NRR JOHN THORPE (EMAIL) NRR PART 21 NOTIFICATION - CONVAL VALVES WELD QUALIFICATIONS The manufacturer provided the following information via facsimile:
"This letter serves to notify the Commission.of two (2) potential safety-related, non-compliances as defined in 10CFR-Part 21. These non-compliances involve Electron Beam (EB) weld qualifications for welds performed on pressure boundary and safety related components of Conval valves; and Electron Beam (EB) welding of cobalt alloy types 6 and 21 to pressure boundary parts of Conval valves.
"Possibly as high as 2,000 forged-body, globe valves generally for use on high temperature steam and hot water in sizes ranging from, 1/2" to 4", possibly involving one or more of these non-compliances, have been supplied by Conval to approximately 25 nuclear power plants over an estimated time period extending from the 1980's to the present. Probably over half of the valves suspected of nonconformances were procured as Commercial Grade valves."
Potentially affected plants are:
Region 1: Fitzpatrick, Indian Point, Pilgrim, Vermont Yankee, Nine Mile Point Region 2:North Anna, Surrey, Oconee, Brunswick, Crystal River, Harris Region 3: Cook, Palisades, Quad Cities, Point Beach Region 4: Arkansas Nuclear One, Fort Calhoun, Palo Verde, Grand Gulf, Waterford, Cooper, South Texas Foreign Plants: Laguna Verde (Mexico), Keoberg (South Africa)
11/09/2007 15:50 8607633557 CONVAL PAGE 01/02 SolVEL 5, 265 FIELD ROAD, RO BOX 1049, SOMERS, CT 06071 PHONE 860-749-0761 FAX 860-763-3557 November 9, 2007 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Fax: (301) 81.6-5151
Subject:
IOCER-Part 21, Notification of Potential Safety Related Noncompliance Deviations
Dear Commissioners:
This letter serves to notify the Commission of two (2) potential safety-related, non-compliances as defined in 10CFR-Part 21. These non-compliances involve Electron Beam (EB) weld qualifications for welds performed on pressure boundary and safety related components of Conval valves; and Electron Beam (EB) welding of cobalt alloy types 6 and 21 to pressure boundary parts of Conval valves.
Possibly as high as 2,000 forged-body, globe valves generally for use on high temperature steam and hot water in sizes ranging from I" to 4", possibly involving one or more of these non-compliances, have been supplied by Conval to approximately 25 nuclear power plants over an estimated time period extending from. the 1980's to the present. Probably over half of the valves suspected of non-coifformances were procured as Commercial Grade valves.
The first non-compliance involved the process for qualifying Electron Beam welds on pressure boundary and safety related components, specifically body-seat welds and welded stem assemblies, on Conval valves. ASME,Section IX and Code Case N62-7 together require that such welds be qualified, in part, by the evaluation of cross sections of weld coupons for adequate penetration per design requirements and for weld. integrity (free of cracks, porosity, etc.). Four (4) cross sections arc required for this evaluation, but Conval performed evaluations on only two (2) cross sections for virtually all. of its approximately 62 EB weld qualifications.
Conval has already re-qualified 8 of the 62 existing weld procedures using four (4) cross sections, and has achieved a 100% success rate. We will re-qualify the remainder of the 62 EB welds, using the original weld coupons, by the end of November, 2007 under the direction of Charles Sumner, Conval's Engineering Manager, with the expectation that all will. be successfully verified. At this time, Conval is confident that the installed population of Conval valves in nuclear power plants are, and will remain, fully operable and functional. We suggest that there are no substantial safety hazards attributable to this issue.
The second deviation involved Electron Beam (EB) welding of cobalt alloy types 6 and 21. to pressure boundary parts of Conval valves, specifically body-seat welds and welded stem assemblies, when, due to a Conval review of its weld procedures and qualifications, it was learned. that welding of cobalt alloy types 6 and 21. are prohibited by Code Case N62-7, the Code Case required to permit EB welding without a bend test.
CLArIipsEAL VALVES
11/09/2007 15:50 8607633557 CONVAL PAGE 02/02 U.S. Nuclear Regulatory Commission November 9, 2007 Page 2 of 2 Although EB welding of cobalt alloy types 6 and 21 is prohibited by Code Case N62-7, Conval' s extensive analysis of the strength of these welded joints in Conval valves revealed that there is adequate strength for proper valve functionality for all valve sizes, process conditions and operational circumstances encountered in nuclear power plants. We therefore suggest that there are no substantial safety hazards attributable to this issue.
Nevertheless, Conval has an alternative joint design that avoids the welding material.
restrictions in Code Case N62-7. That design will be available for licensees requesting it.
This identical. valve design has been used with great success for almost 40 years in super-critical and other steam applications, operating at temperatures and pressures that are well in excess of those encountered in nuclear power plants. Therefore, Conval will be pursuing a Code Case permitting EB welding of the aforementioned cobalt alloys.
The weld qualification process and material restriction issues were identified during a weld-qualification research project undertaken in late September, 2007. Conval's Engineering Department initiated a study of the issues to determine their validity, and on November 8, Charles A- Sumner, Engineering Manager concluded an extensive engineering analysis and issued a formal report to Conval's president, Donald L. Curtin, recommending notification of the NRC relative to the two non-conformances cited above. On November 9, Donald Curtin faxed this report to the NRC and will follow up with a mailed copy of it along with Conval's applicable engineering reports.
Conval is in the process of gathering user plant information and officially notifying the individual plants of these issues. Resolution of the weld. qualification and welding material restriction non-conformances will be guided by input from users and appropriate regulatory officials; Conval will research all applicable customer orders and respond diligently to any user requirements for remedial action. Possibly over half of the valves suspected of non-confoimances were procured as Commercial Grade valves.
It is anticipated that most, if not all, licensees will determine that no substantial safety hazards are attributable to these welding non-compliances.
Tf you have any questions or need additional information concerning this notification, please contact me directly.
Vely'truly yours,
,,ý NA, INC.
Donald L. Curtin President Cc: F. Siver, Chain-nan, CEO, Conval.
T). Williams, Vice President Finance, Conval M. Hendrick, Vice President Sales and Marketing, Conval K. Smith Ti, Quality Assurance Manager, Conval C. Sumner, Engineering Manager, Conval I. Makuch. Nuclear Accounts Representative, Conval CLAIMIPSEAL VALVES
CONVAL 10CFR21 2112107 Listing of Plant Notifications CD NRC Report # 43166 CD Date of Supplied Specific NCA3800 Undedicated 8J &8K Owner/Plant Original Notice Plant Listing Material Split Rings Split Rings. Not Affected
-,4 AEP/DCCook 2/21/2007 312312007 X X X C APS/Paio Verde 2/21/2007 3(23/2007 X CFPJLaguna Verde/Mexico 212112007 3120W2007 X cn CD Constellation(Nine Mile 2/21/2007 3123)2007 X D Consumers Energy(Palisades 2/21/2007 3(2012007 X X X M Dom. V[rginia.N.Anna &Surrey 2121/2007 3/1612007 X X X W in DuketOconee 2121/2007 312012007 X -n Entergy/Arkansas One 212112007 3f2012007 X EntergydJAFitzpatrick 212112007 3(2312007 X X Entergy/Grand Gulf 2(2112007 3120/2007 X Entergy(IP 2 & 3 2/21(2007 3/2312007 X X X Entergy/Pilgrim Station 2/21(2007 311512007 X X X Entergy/Waterford 3 2/21(2007 3/20/2007 X EntergyNt. Yankee 2121(2007 3115/2007 X X X ExelonlOyster Creek/Quad Cities 2/2112007 3123/2007 X X Koeberg Staticn/CVT/S.Africa 313012007 313012007 X X X 0
Nebraska Public Power/Cooper 2/2112007 312012007 X OPPD/Fort Calhoun 2/21)2007 3115/2007 X 1>
Pofnt Beach 212112007 3t23/2007 X X X Progres Energy/Carolinas 212122007 31712007 X X X Progress Energy/CyrstaI River 2121/2007 3/1612007 X Progress Energy/Harris 2121)2007 312012007 X South Texas Project 2(21/2007 3120(2007 X Weir Valves 2(21/2007 312012007 X X X CD CD Prepared by Irene Makuch 712412007 Page I IQ