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| Entered date | Event description | |
|---|---|---|
| ENS 43266 | 30 March 2007 10:30:00 | During routine operations on the RNII production floor, it was observed that an incorrect torque wrench was being used at mechanical assembly to tighten the Sensor Module Lock Nut. The incorrect tool was calibrated to a value of 12.5 ft-lb, resulting in undertorquing of the lock nut. The incorrect torque wrench was removed from service and replaced with a tool calibrated to the correct torque value of 35 ft-lb. RNII reworked all affected transmitters that had not yet shipped to the correct torque value. Assembly with the incorrect tool could result in certain pressure transmitters having a degraded environmental seal between the sensor module and the electronics housing during or after a seismic event. The five affected models have been delivered to the Byron and Comanche Peak nuclear stations. |
| ENS 42438 | 21 March 2006 16:55:00 | 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. |
| ENS 42233 | 27 December 2005 18:14:00 | The Supplier provided this notification via facsimile and is summarized below: A multi-meter used in the calibration of certain pressure instruments went out of calibration between 10/10/2005 and 11/18/2005. These instruments may not conform to the published accuracy specification of +/- 0.25% of calibrated span. Rosemont Nuclear Instruments, Inc (RNII) successfully recalibrated all affected transmitters that had not yet shipped from its facility. The instruments affected by this failure are: (a) certain Model 1152 gage and differential pressure transmitters with model codes beginning with 1152GP, 1152DP, or 1152HP, inclusive of pressure measuring range codes 3, 4, 5, and 6 (the range code is the 7th position in the model string); and (b) certain Model 1153 Series B and 1153 Series D gage and differential pressure transmitters with model codes beginning with 1153GB, 1153DB, 1153HB, 1153GD, 1153DD, or 1153HD inclusive of pressure measuring range codes 3, 4, 5, and 6 (the range code is the 7th position in the model string); and (c) certain Model 1154 and 1154 Series H gage and differential pressure transmitters with model codes beginning with 1154GP, 1154DP, 1154HP, 1154DH, or 1154HH inclusive of pressure measuring range codes 4, 5, and 6 (the range code is the 7th position in the model string). The end user must determine the impact of this potential non-conformance on its plant operations and safety and take action as deemed necessary. If an affected pressure transmitter has been successfully calibrated after receipt from RNII or will be calibrated prior to installation, no further action should be required.
Rosemount provided the following information via facsimile: Yesterday, Rosemount Nuclear Instruments, Inc. (RNII) submitted a notification under 10 CFR Part 21. The submission to the NRC did not include Attachment A, which lists all of the affected U.S. licensees. This fax includes the letter and the attachment. RNII has initiated communication with its customers. The notification letter and attachment A have been sent to each of the affected customers. Attachment A provides Purchase Order Numbers, Model Numbers, Serial Numbers, and Calibration Dates for instruments provided to the following affected licensees: Dominion Generation, First Energy Corporation, Progress Energy Carolinas, Georgia Power Co., and Southern Nuclear Operating Co. Notified R1 DO (M. Sykes), R2 DO (M. Lesser), R3 DO (D. Hills), R4 DO (J. Clark), NRR (C. Holden and O. Tabatabai) |