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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 43566 | 14 August 2007 05:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Rosemeount 1154 Pressure Transmitter Calibration Problem | The supplier provided the following information via facsimile: Pursuant to 10 CFR Part 21, section 21.21(b) Rosemount Nuclear Instruments, Inc. (RNII) is writing to inform NRC that a total of ten (10) Model 1154 and 1154 Series H output range code 4 pressure transmitters whose model code includes special option suffix N0026 or N0079 may not calibrate at all of the published values (9 shipped to 2 utility sites in the United States). During evaluation of two returned Model 1154 output range code 4 pressure transmitters with special option suffix N0026, the cause of the customer-reported calibration problem was isolated to the amplifier circuit card assembly (CCA). Upon replacement of the amplifier CCAs the two affected transmitters calibrated and functioned normally. During root cause analysis it was observed that a single resistor (R316) on each affected amplifier CCA had an incorrect resistance value. The R316 resistor enables a standard upper range limit (URL) of a transmitter with output range code four to be increased from 150 inches water to 210 inches water in combination with a minimum span of 75 inches water. This R316 resistor allows the transmitter to achieve performance specifications, calibration ranges, and spans as indicated by the special option drawing. To meet site specific application requirements transmitters may be field recalibrated to different upper and lower range values and/or spans. Model 1154 and 1154 Series H transmitters with special option suffix N0026 or N0079 and amplifier CCAs whose R316 resistors were not replaced during the sub-assembly process, will have incorrect resistance values and may not calibrate to all upper and lower range values and/or spans published for the applicable special option. However, if an affected transmitter has been successfully calibrated, having the incorrect resistance value will not adversely affect transmitter performance during normal operation or accident conditions. The manufacturing records for the two returned Model 1154 transmitters (with amplifier CCAs with part number 01154-0001-0006) were carefully reviewed. The sub-assembly traveler lacked the required material traceability information, indicating that the R316 resistors were not replaced. In an abundance of caution RNII carefully reviewed all sub assembly travelers for part number 01154-000l-0006. No other discrepancies were found. The corrective action which has been taken; the name of the individual or organization responsible for that action; and the length of time taken to complete that action: (a) RNII verified all transmitters in production and finished goods with applicable special options utilizing 01154-0001-0006 amplifier CCA's contained the correct board and resistor. No discrepancies were found. (Complete: 7/24/2007) (b) RNII evaluated all 01154 CCA's in production to ensure they contained the correct resistor. No discrepancies were found. (Complete: 7/20/07) (c) RNII examined all manufacturing paperwork for 01154-0001-0006 amplifier CCAs built and shipped prior to 7/24/2007. No additional discrepancies were found. (Complete: 7/25/2007) (d) An internal corrective action request was initiated. All corrective actions will be completed by 8/15/07. The end user is advised to determine the impact of this potential non-conformance on its plant operations and safety and take action as deemed necessary. RNII can supply replacement 01154-0001-0006 amplifier CCAs which can be installed per section five of the product manual or the transmitter can be returned to RNII for rework. If it is determined that return of affected transmitter(s) is required, RNII should be contacted to facilitate the return process. Plants affected: Saint Lucie (6 received) , and Waterford 3 (3 received). | ||
| ENS 42438 | 21 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 | 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. |