ENS 54485
ENS Event | |
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05:00 Jan 21, 2020 | |
Title | Part 21 Report - Target Rock 1" and 2" Fail Closed Solenoid Operated Valve Assemblies Unauthorized Modification During Assembly |
Event Description | The following was received via email:
Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply. Condition 1 (Modified Fixed Core) The purpose of the fixed core is to provide the proper amount of magnetic pull force between itself and the plunger when the solenoid coil is energized. The fixed core is installed within the bonnet assembly and "fixed" in place by a "dimpling" process which captures a machined groove on the fixed core. During Assembly & Testing of a TR Solenoid Operated Valve, a fixed core unexpectedly came out of the bonnet assembly. Further inspections of the fixed core revealed unauthorized modification to the part beyond its design basis to force installation into the bonnet assembly. In the event a modified fixed core was to dislodge from its location within the bonnet, the specific valve assembly would fail to operate to the open position when the solenoid is energized and would remain in its fail safe closed position. Condition 2 (Main Disc Lift Misadjustment): The objective of the disc lift adjustment is to ensure the main disc is in contact with the bonnet base, which provides an "up stop" position while maintaining a minimum clearance between the plunger and the fixed core. Excessive clearance between the plunger and the fixed core reduces the available magnetic force. Conversely, improper adjustment, allowing contact between the plunger and the fixed core, may cause impact damage to the assembly during full pressure/temperature actuation and reduces the maximum flow (Cv) through the valve assembly. It was noted that a disc lift adjustment was not adjusted properly and would reduce the maximum flow. The date on which the information of such defect or failure to comply was obtained. Condition 1 (Modified Fixed Core): During the investigation of the suspect technician, TR identified conditions, which required independent inquiry and subsequently confirmed intentional modification of the fixed core. On December 5, 2019, TR Engineering confirmed the condition. Condition 2 (Main Disc Lift Misadjustment): On November 22, 2019, TR Engineering performed a worst case Cv calculation to determine the amount of restricted flow that would result in the event a 1" y-body valve assembly was short stroked. This would reduce the flow of a 1" y-body valve assembly from a rated Cv of 15 to approximately a Cv of 14. The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action. Condition 1 (Modified Fixed Core): The discrepant bonnet assembly/fixed core was documented on a NCR (Non Conformance Report) and scrapped. A new bonnet assembly was issued to the valve kit. The valve assembly was reassembled, retested and successfully passed all required production testing. This was an unauthorized modification performed by a single individual (suspect technician). Four additional A& T technicians involved in the bonnet dimpling process were interviewed. All four technicians stated they have never intentionally modified components nor have they ever seen anyone intentionally modifying components in any form. TR investigation considers this to be isolated to the suspect technician. The suspect technician no longer works for the company. Condition 2 (Main Disc Lift Misadjustment): The initial valve assembly was readjusted in accordance with the applicable technical manual and solenoid valve adjustment procedure. The valve assembly was re-tested per the applicable production test procedure and successfully passed all required testing. Upon further investigation of valves assembled by the suspect technician, an additional 3 of 10 valve assemblies were verified to have misadjusted main disc lift. The misadjusted valves were readjusted, tested and successfully passed all production testing prior to shipment. All technicians working on solenoid valve assemblies were given an individual technician qualification exam to determine their understanding of this adjustment in accordance with the existing work instructions. Each technician was tested individually, with Engineering present as a witness. All technicians demonstrated a clear understanding and followed the necessary instructions/procedures to properly adjust the disc lift. TR determined the suspect technician did not follow the official work instructions for the disc lift adjustment in an effort to save time during this process. TR investigation concludes this defect is isolated to the suspect technician. The suspect technician no longer works for the company. This was the same technician involved in Condition 1. Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees. Condition 1 (Modified Fixed Core): TR performs production testing on all valve assemblies prior to shipment. TR considers this testing adequate screening to identify this condition at the factory. Satisfactory testing provides reasonable assurance the stated condition does not exist in shipped product. However, TR recommends un-installed bonnet assemblies and complete valve assemblies be returned to TR for re-inspection. This condition potentially affects valve models and bonnet assemblies detailed in Attachment 1 manufactured between 1/1/2018 and 10/31/2019. Any installed valves containing these parts should be reviewed and evaluated for history of operational testing anomalies. Many of these installed valves are subject to regular plant testing, such as 1 OCFR50 Appendix J. Satisfactory performance in this testing will provide reasonable assurance of an acceptable valve condition. Condition 2 (Main Disc Lift Misadjustment): All un-installed Valve Assemblies should be checked to determine if a misadjustment of the main disc lift exists. Although the process to check for a misadjusted valve is not difficult, it requires partial valve disassembly. The instructions for proper adjustment are located in the valve specific Technical Manual. Any 1" Y-body solenoid valve assemblies that have been installed should be reviewed and evaluated by each end user regarding the acceptability of having a lower flow (Cv) rating of 14 in lieu of 15 for the specific system in which they are installed. Any opportunity to disassemble the valve assembly for inspection and readjustment is recommended. This condition potentially affects valve models detailed in Attachment 1 manufactured between 7/1/2015 and 10/31/2019. Should you have any questions regarding this matter, please contact Michael Cinque, General Manager at (631) 293-3800 Very Truly Yours, Michael Cinque General Manager Target Rock, Business Unit of Curtiss-Wright Flow Control Corporation Affected sites are Arkansas Nuclear One, Beaver Valley, Brunswick, Calvert Cliffs, Farley, Fitzpatrick, Hope Creek, Millstone, Nine Mile Point, Oconee, Palo Verde, Sequoyah, Shearon Harris, St. Lucie, South Texas Project, Vogtle, Watts Bar |
Where | |
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Curtiss Wright Flow Control Co. East Farmingdale, New York (NRC Region 1) | |
Organization: | Curtiss Wright Flow Control Co. |
Reporting | |
10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
Time - Person (Reporting Time:+11.2 h0.467 days <br />0.0667 weeks <br />0.0153 months <br />) | |
Opened: | John Debonis 16:12 Jan 21, 2020 |
NRC Officer: | Rodney Clagg |
Last Updated: | Jan 21, 2020 |
54485 - NRC Website | |
Curtiss Wright Flow Control Co. with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 546742020-04-20T06:00:00020 April 2020 06:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Report - Defect in Thermocouple Low Level Amplifier Modules ENS 544852020-01-21T05:00:00021 January 2020 05:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Report - Target Rock 1" and 2" Fail Closed Solenoid Operated Valve Assemblies Unauthorized Modification During Assembly 2020-04-20T06:00:00 | |