ENS 42438
ENS Event | |
|---|---|
06:00 Mar 21, 2006 | |
| Title | Part 21 Notification Concerning Rosemount Transmitters |
| Event Description | The licensee provided the following information via facsimile:
Pursuant to 10 CFR Part 21, section 21.21(b), Rosemount Nuclear Instruments, Inc. (RNII) provided information that certain Rosemount Pressure Transmitters may not conform to RNII's published qualified life specification. The specific models affected are: (a) Certain Model 1153 Series B and 1153 Series D pressure transmitters of all range codes and measuring types (gage, differential, absolute) shipped between 16 December 2005 and 13 January 2006, and (b) Certain Model 1154 and 1154 Series H pressure transmitters of all range codes and measuring types (gage, differential, sealed reference) shipped between 16 December 2005 and 13 January 2006 For every RNII Model 1153 and Model 1154 transmitter, four diodes are used on a circuit card assembly which is installed and sealed within the sensor module sub-assembly. The primary function of these diodes is to convert an AC oscillator signal to a DC current that is proportional to the capacitance of the sensor. The diodes (P/N D2911218A) are manufactured by Microsemi Corp (MSG). Recently during standard receiving inspection, it was noted that the glass packaging on several of the diodes exhibited an unusual 'cloudy' appearance. Upon supplier analysis it was determined that the cloudy appearance was due to interaction between cleaning solution and metallic components of the diode. Cleaning solution was able to penetrate the glass diode package because of a poor hermetic seal. Over time, this condition could degrade the performance and reliability of the diode, particularly at elevated temperatures. The resultant effect on the transmitter might include degraded temperature effect performance and increased drift between calibration cycles. Through further internal investigation MSC was able to bound the potential problem to two lot codes. These lot codes were traced from MSC through our circuit card supplier and to RNII to identify the shipped transmitters affected by this notification. RNII built up several test transmitters using diodes having a cloudy appearance and performed thermal aging on the transmitters to simulate typical operating conditions, followed by high temperature testing. Test results suggest that potentially affected transmitters would operate within published performance specifications, including the Nuclear Steam Pressure/Temperature specification. Nonetheless, RNII and MSC were unable to demonstrate the long term reliability of the suspect diodes over the full qualified life of the transmitter. Therefore, based on analysis of the test results, RNII has established the following qualified life limits for transmitters affected by this notification. This specification supersedes the published qualified life for all pressure transmitters affected by this notification: Interim Qualified Life = 5.1 years @ 120 F Operating Temperature RNII does not have sufficient information relative to each end use's specific applications to determine the potential safety-related impact of this notification to each end user's plant. Each end user must determine the impact on its plant operations and plant safety and take action as deemed necessary. RNII recommends that "the end user must determine the impact of this potential non-conformance upon its plant's operation and safety, and take action as deemed necessary. RNII recommends that potentially affected transmitters be returned to RNII for replacement of the module at the end user's earliest opportunity and consistent with the abbreviated interim qualified life specification. RNII requests that the end users contact RNII to facilitate the transmitter return process as necessary. Plants which have been supplied these transmitters: Nine Mile Point; Catawba; River Bend; Quad Cities; Braidwood; Dresden; Perry; Turkey Point; Vogtle; Palisades; and Hope Creek. Rosemount is in the process of contacting the end users. |
| Where | |
|---|---|
| Rosemount Nuclear Instruments, Inc Chanhassen, Minnesota (NRC Region 3) | |
| Organization: | Rosemount Nuclear Instruments, Inc |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+10.92 h0.455 days <br />0.065 weeks <br />0.015 months <br />) | |
| Opened: | David Roberts 16:55 Mar 21, 2006 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Mar 21, 2006 |
| 42438 - NRC Website | |
Rosemount Nuclear Instruments, Inc with 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | |
WEEKMONTHYEARENS 435662007-08-14T05:00:00014 August 2007 05:00:00
[Table view]10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation Rosemeount 1154 Pressure Transmitter Calibration Problem ENS 424382006-03-21T06:00:00021 March 2006 06:00:00 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation Part 21 Notification Concerning Rosemount Transmitters 2007-08-14T05:00:00 | |