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| Entered date | Event description | |
|---|---|---|
| ENS 44082 | 20 March 2008 12:32:00 | The following information was received via fax: Re: Notification under 10 CFR Part 21 for certain Model 3051N Pressure transmitters Pursuant to 10 CFR Part 21, section 21.21(b) Rosemount Nuclear Instruments, Inc. (RNII) is writing to inform you that a limited number of Model 3051N pressure transmitters listed in the attachment may exhibit erratic, unstable output prior to an off-scale failure. The affected transmitters were shipped from RNII between March 31, 2002 and November 20, 2002. 1.0 Name and address of the individual providing the information: Mr. Marc D. Bumgarner Vice President & General Manager Rosemount Nuclear Instruments, Inc. 8200 Market Boulevard Chanhassen, MN 55317 2.0 Identification of items supplied: Certain Model 3051N pressure transmitters identified in the attachment. 3.0 Identification of the firm supplying the item: Rosemount Nuclear Instruments, Inc. 8200 Market Boulevard Chanhassen, MN 55317 4.0 Nature of the failure and potential safety hazard: The Model 3051N Smart Pressure Transmitter is dedicated for nuclear use consistent with the requirements of 10 CFR Part 21. It is qualified for use in safety related applications per IEEE 323-1983 (mild environment) and IEEE 344-1987 for seismic applications as documented in its associated qualification reports. The Model 3051N pressure transmitter contains an application-specific integrated circuit (ASIC) which performs the Digital to Analog Conversion (DAC). Procurement and production records indicate that a limited number of Model 3051N pressure transmitters manufactured between January 2002 and October 2002 have DAC ASICs which may contain phosphorus as the encapsulation material. ASIC industry experts have since determined that under certain conditions the phosphorus compound can lead to reduced insulation resistance of the integrated circuit, with potentially adverse impact on performance. As a result, ASIC and IC manufacturers eliminated the use of phosphorus in their products. Industry experts have examined the performance of phosphorus materials in electronic circuits under various conditions and estimated a potential ASIC failure rate of approximately 1% for the general population of phosphorus-containing electronic circuits. Three Model 3051N transmitters have recently been returned to RNII due to erratic, unstable, or off-scale output. Failure analysis identified the phosphorus-containing encapsulation material of the DAC ASIC as the cause of failure for these transmitters. These transmitters were installed and performing properly for 3-5 years before failure. Failure of the DAC ASIC depends on several factors, including: Phosphorus concentration Spacing of ASIC leads Voltage driving the ASIC (which affects operating temperature) Ambient temperature The observed failure rate of the DAC ASIC in Model 3051N pressure transmitters indicates a potential reliability concern. As a result, notification is being made in accordance with 10 CFR Part 21 to customers that purchased a transmitter from the potentially affected population. A transmitter with a failing DAC ASIC will annunciate itself by erratic or unstable output, followed by off-scale output (high or low). 5.0 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: The use of phosphorus in the DAC ASIC was eliminated in October 2002. Model 3051N pressure transmitters affected by this notification may be returned to RNII for replacement at no charge. 6.0 Any advice related to the potential failure of the item: The end user is advised to determine the impact of this potential reliability issue upon its plant's operation and safety, and take action as deemed necessary. Affected transmitters may be returned to RNII for replacement at no charge. Rosemount Nuclear Instruments, Inc. is committed to the nuclear industry and: remains dedicated to the supply of high quality products to our customers. If you have any questions, or require additional information related to this issue, please contact: Mike Dougherty (205) 865-1112, Gerard Hanson (952) 949-5233, Bob Cleveland (952) 949-5206, or Matt Doyle (952) 949-5204. Facilities affected which were identified in the referenced attachments: Cook Nuclear Plant, Vermont Yankee, Quad Cities Nuclear Station, and Robinson. |
| ENS 43826 | 6 December 2007 14:03:00 | Rosemount Nuclear Instruments, Inc. (RNII) reported that certain Model 1152, 1153 Series B and D, and 1154, and 1154 Series H Pressure Transmitters may have inadequate thread engagement between the electronics housing and sensor module. Transmitters affected by this notification may not confirm to RNII specifications under accident conditions. Supplier testing has determined that no immediate risk exists, however it is RNII's opinion that two threads of engagement may not be sufficient to assure that the product will perform its intended safety function over the qualified life of the transmitter. The following are the potentially affected licensees: Oyster Creek, Calvert Cliffs, Kewaunee, North Anna, Millstone, Surry, Turkey Point, Vogtle, Diablo Canyon, Shearon Harris, South Texas Project, Browns Ferry, and Wolf Creek. |
| ENS 43287 | 6 April 2007 16:58:00 | Model 1152 pressure transmitters shipped to facilities between June 12, 2006 and December 20, 2006 may exhibit leakage from a threaded connection interface between the flange and the vent/drain valve seat if subjected to a process pressure greater than 2000 psi. Consequently, performance to published hydrostatic test specifications, or sealing at the maximum working pressures above 2000 psi cannot be assured. The following potentially affected utilities were identified: Ameren UE, Alabama Power Co., Detroit Edison Co., Dominion, Entergy, Exelon Generation Co., First Energy Corp., FPL Duane Arnold LLC, Georgia Power Co., Nuclear Management Co., Omaha Public Power District, Pacific Gas and Electric, Pennsylvania Power and Light Co., Progress Energy Florida Inc., South Carolina Electric and Gas, and Tennessee Valley Authority. |