Part 21 Report - 1995-227
ACCESSION #: 9511150265 Rosemount Nuclear Instruments Rosemount Nuclear Instruments, Inc. 12001 Technology Drive Eden Prairie, MN 55344 USA November 10, 1995 Tel 1 (612) 828-8252 Fax 1 (612) 828-8280 Re: Notification under 10 CFR Part 21 on Rosemount Nuclear Instruments, Inc. Model 1159 Remote Seal Systems with DC 704 Fill Fluid. Pursuant to 10CFR21 Paragraph 21.21(b), Rosemount Nuclear Instruments, Inc. (RNII) is writing to inform you that the Model 1159 Remote Seal System may not perform in accordance with published specifications when used with DC 704 fill fluid. The potential for performance degradation is caused by the reaction at certain ambient temperatures of DC 704 fill fluid with Rando HD-46 machine fluid residue located on the remote seal housing. The reaction between DC 704 fill fluid and Rando HD-46 machine fluid may result in outgassing of the DC 704 fill fluid causing a zero shift in the output of the transmitter/remote seal assembly. RNII Model 1159 remote seal systems are qualified per IEEE Std. 323 and 344 when used with RNII Model 1152, 1153, and 1154 transmitters. By design, Model 1159 remote seal capillaries are filled with fluid at the RNII factory and cannot be filled in the field. The standard remote seal fill fluid offering is water. RNII offers DC 200 and DC 704 fill fluids as optional fill fluids. RNII has been advised that a transmitter/remote seal with DC 704 fill fluid failed in a commercial (non-nuclear) application. The failure mode was a continuous shift in transmitter zero when the remote seal was subjected to ambient temperatures in excess of 500 degrees F (260 degree C). Subsequent failure analysis concluded the cause for the shift in zero was due to the DC 704 fill oil outgassing from a reaction to machining fluid residue on the remote seal housing. The machining fluid was identified as Rando HD-46. Rando HD-46 is used by the supplier of remote seal housings as a machine lubricant on machinery used to manufacture the parts. This machining fluid is formulated to act as a corrosion inhibitor by leaving a residue on the part. RNII is not aware of any failures of this type in nuclear power plant applications. However, Model 1159 nuclear grade remote seal housings are purchased from the same supplier as the RMD parts and therefore could contain the same machine oil residue. RNII has conducted tests using all three Model 1159 fill fluid options; water, DC 200 and DC 704. From the testing, RNII has concluded that Rando HD-46 reacts only with DC 704 fill fluid where transmitter output can be affected. FISHER-ROSEMOUNT 10CFR21 Notification Model 1159 Remote Seal Assembly November 10, 1995 Page 2 of 4 Laboratory analysis of DC 704 reacting with Rando HD-46 indicates that a reaction between fluids begins at 122 degrees F (50 degrees C) and accelerates beginning at 446 degrees F (230 degrees C). RNII has completed testing of transmitter/remote seal assemblies with DC 704 fill fluid which monitored transmitter output for 28 days at an ambient temperature of 200 degrees F (93.33 degrees C). Test results showed no adverse affect on transmitter zero. RNII does not have sufficient data to determine the effect on transmitter output at ambient temperatures between 122 degrees F (50 degrees C) and 446 degrees F (230 degrees C). We conclude that since a reaction is present, outgassing of the DC 704 fill fluid can occur, and therefore a potential progressive zero shift is possible. 1.0 Name and address of the individual providing the information: Mr. Mark Van Sloun Vice President & General Manager Rosemount Nuclear Instruments, Inc. 12001 Technology Drive Eden Prairie, MN 55344 2.0 Identification of items supplied: Model 1159 Remote Seal Assemblies, with DC 704 Fill Fluid, supplied as a configured system with model 1152, 1153 or 1154 transmitters. The list of units is referenced in the enclosure entitled Attachment A. Remote seal assemblies with DC 704 fill fluid are identified by the "B" character at the end of the model number. (e.g. 1159A10B). 3.0 Identification of firm supplying the item: Rosemount Nuclear Instruments, Inc. 12001 Technology Drive Eden Prairie, MN 55344 4.0 Nature of the failure and potential safety hazard: This notification is issued to inform all users of Model 1152, 1153 and 1154 transmitters with Model 1159 Remote Seal Assemblies, configured with DC 704 fill fluid, of the potential for zero shifts outside normal design specifications. The zero shift is caused from the reaction of the DC 704 fill fluid with a machining fluid residue, Rando RD-46, which remained on the remote seal housing. RNII does not have sufficient information to determine the safety impact related to plant applications. Licensees must determine the impact on plant operations and plant safety and take action as deemed necessary. FISHER-ROSEMOUNT 10CFR21 Notification Model 1159 Remote Seal Assembly November 10, 1995 Page 3 of 4 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: RNII has concluded that DC 704 fill fluid reacts with machine oil Rando HD-46 at ambient temperatures as low as 122 degrees F (50 degrees C). Although RNII has not confirmed any field failures at nuclear plant applications, RNII has been advised of one field failure of a commercial (non-nuclear) transmitters/remote seal systems using DC 704 fill fluid at ambient temperatures over 500 degrees F (260 degrees C). RNII Actions: 1.0 Under Corrective Action Request (CAR) 95-0048, RNII will eliminate the use of Rando HD-46 machining oil in the supply of these parts. The scheduled implementation date is December 1, 1995. This will eliminate the potential failure mode for future transmitter/remote seal assembly shipments. 2.0 Remedial action has been taken to remove Rando HD-46 from all applicable parts in current stock. User Actions: 1.0 Users with affected transmitter/remote seal assemblies installed in plant processes have the following options: A. Trend transmitter output for observation of zero shift outside design specifications. B. Remove from service and replace with new transmitter/ remote seal system. 2.0 Users with affected transmitter/remote seal assemblies located in stores can return the units to RNII for replacement of the remote seal assembly. Mr. Van Sloun is responsible for any further action related to this issue. FISHER-ROSEMOUNT 10CFR21 Notification Model 1159 Remote Seal Assembly November 10, 1995 Page 4 of 4 6.0 Any advice related to the potential failure of the item: No further information is forwarded. RNII has a strong commitment to the nuclear industry and assures you that we are dedicated to the supply of high quality products and services to our customers. If there are any questions, or you require additional information related to this issue, please contact Tim Layer (612) 828-8240 or Jane Sandstrom and Ian Baldry (612) 828-8250. Sincerely, Rosemount Nuclear Instruments, Inc. M. L. Van Sloun Vice President & General Manager encl.: Attachment A MVS:TJL FISHER-ROSEMOUNT ATTACHMENT A "MODEL 1159 REMOTE SEAL" Sheet 1, Page 1, omitted. *** END OF DOCUMENT ***
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Page Last Reviewed/Updated Wednesday, March 24, 2021