ENS 47246
ENS Event | |
|---|---|
05:00 Aug 30, 2011 | |
| Title | Notification That Certain Rosemount Pressure Transmitters May Not Perform Their Intended Safety Function |
| Event Description | The following is a summary of a Part 21 notification was received from Rosemount via facsimile:
Re: Notification under 10 CFR Part 21 on certain Rosemount Model 1153 Series B, 1154 and 1164 Series H Pressure Transmitters Pursuant to 10 CFR Part 21, section 21.21(b), Rosemount Nuclear Instruments, Inc. (RNII) is writing to inform [the NRC] that one (1) Model 1153 Series B, fourteen (14) Model 1154, and twenty (20) Model 1154 Series H pressure transmitters may not perform their intended safety function. Rosemount Nuclear Instruments, Inc. does not have complete information relating to specific plant applications and therefore cannot determine the potential effects of the condition on plant operation. The thirty-five (35) potentially affected Model 1153 Series B, 1154, and 1154 Series H pressure transmitters were shipped from RNII between April 19, 2011 and August 12, 2011. [The list of Plant Sites that have received the affected transmitters is provided at the end of this report.] If you have any questions, or require additional information related to this issue, please contact: Mike Dougherty (208) 865 -1112 or Tracy Kaluzniak (952) 949-7159. Identification of items supplied: One (1) Model 1153 Series B, fourteen (14) Model 1154, and twenty (20) Model 1154 Series H potentially affected units have been shipped. Identification of firm supplying the item: Rosemount Nuclear Instruments, Inc. 8200 Market Boulevard Chanhassen, MN 55317 Nature of the failure and potential safety hazard: On each Model 1153 Series B, 1154, and 1154 Series H transmitter, four diodes are used on a circuit card assembly which is installed within the welded sensor module subassembly. These diodes convert the AC oscillator signal to a DC current proportional to the pressure applied to the sensor. The diodes (P/N DZ911218A) are manufactured by Microsemi Corporation (MSC). Recently an unexpected drop in yield was identified during electrical testing of the circuit card assembly. A hold was placed on production to further investigate the issue. It was determined that the drop in yield was caused by intermittent open diodes on the circuit card assembly. Failure of one diode will result in an off-scale failure of transmitter output. Failure of two or more diodes may result in an on-scale failure of transmitter output. MSC determined that the intermittent open electrical failures were the result of a poor solder bond formation within the diode at the cathode lead. This was caused by either inadequate heat flow or surface contamination during the component manufacturing process. Working with MSC, RNII used material traceability data to confirm the potential problem was limited to one manufacturer's lot code of the diode. RNII was then able to utilize material traceability data to further identify the specific shipped transmitters affected by this notification. On August 30, 2011, it was concluded that a substantial safety hazard may exist. Rosemount Nuclear Instruments, Inc. does not have sufficient information to determine the safety impact related to the potentially anomalous output in plant applications. As a result, a notification about the potential substantial safety hazard is being made in accordance with 10 CFR Part 21 to customers who purchased one or more of the thirty-five (35) potentially affected Model 1153 Series B, 1154, or 1154 Series H pressure transmitters. The corrective action which is taken, the name of the individual or organization responsible for that action, and the length of time taken to complete that action: (a) RNII held shipments of completed Model 1153 Series B, 1154, and 1154 Series H transmitters and determined which specific units were assembled with diodes from the suspect lot code. (b) RNII quarantined all Model 1153 Series B, 1154, and 1154 Series H transmitters and sub-assemblies in manufacturing while a determination was made as to which specific units were assembled with diodes from the suspect lot code. (c) RNII worked with the diode supplier (MSC) to determine the root cause and identify the suspect lot code. Since this part is no longer being manufactured by MSC, no corrective actions were implemented at MSC. (d) RNII is in the process of reworking all unshipped Model 1153 Series B, 1154, and 1154 Series H transmitters and subassemblies that were completed or in manufacturing that contained diodes from the suspect lot code. (e) Potentially affected pressure transmitters can be returned and reworked at the factory at the end user's request. (f) RNII is qualifying a substitute diode to replace the obsolete DZ911218A diode. The qualification is expected to be complete within the next six months. This qualification will be documented in an update to the Model 1153 Series B, 1154, and 1154 Series H qualification reports Any advice related to the potential failure of the Item: RNII recommends that users review the application where any of the thirty-five (35) potentially affected Model 1153 Series B, 1154 and 1154 Series H transmitters are used to determine any safety considerations in the operation of the plant. RNII recommends that potentially affected transmitters be returned to RNII for rework at the end user's earliest opportunity. List of Affected Sites: U.S Facilities Calvert Cliffs -5 Transmitters Oconee -2 Transmitters San Onofre -1 Transmitter River Bend -1 Transmitter Waterford -1 Transmitter Diablo Canyon -1 Transmitter Farley -4 Transmitters Foreign Facilities Shin Kori -1 Transmitter Ringhals -3 Transmitters Fuqing -4 Transmitters Fangjishan -4 Transmitters Yangjiang -4 Transmitters Tihange -1 Transmitter Asco II / Vandellos II -3 Transmitters |
| Where | |
|---|---|
| Rosemount Nuclear Instruments Chanhassen, Minnesota (NRC Region 3) | |
| Organization: | Rosemount Nuclear Instruments |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+178.98 h7.458 days <br />1.065 weeks <br />0.245 months <br />) | |
| Opened: | Duyen Pham 15:59 Sep 6, 2011 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Sep 6, 2011 |
| 47246 - NRC Website | |
Rosemount Nuclear Instruments with 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | |
WEEKMONTHYEARENS 472462011-08-30T05:00:00030 August 2011 05:00:00
[Table view]10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation Notification That Certain Rosemount Pressure Transmitters May Not Perform Their Intended Safety Function 2011-08-30T05:00:00 | |