ML20206D836
| ML20206D836 | |
| Person / Time | |
|---|---|
| Issue date: | 04/07/1987 |
| From: | Baker E, Naidu K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML20206D803 | List: |
| References | |
| REF-QA-99900271 NUDOCS 8704130438 | |
| Download: ML20206D836 (8) | |
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ORGANIZATION: ROSEMOUNT INCORPORATED EDEN PRAIRIE, MINNESOTA REPORT INSPECTION INSPECTION NO.: 99900271/87-01 DATE: 1/27-29/87 ON-SITE HOURS: 20 CORRESPONDENCE ADDRESS: Rosemount, Incorporated ATTN: W. Koch, Director of Quality Assurance 12001 West 78th Street o
Eden Prairie, Minnesota 55344 ORGANIZATIONAL CONTACT: G. D. Anderson, Supervisor, OA TELEPHONE NUMBER: (612) 828-3660 NUCLEAR INDUSTRY ACTIVITY: Manufactures transmitters to measure absolute, gage, and differential pressures; flow and level trip / calibration units; and resistance temperature detectors.
. f) b (A- 5 ASSIGNED INSPECTOR:
K. R. Naidu, Reactive Inspection Section (RIS) Date)
APPROVED BY: I G V Edward T. Bak'er, Acting Chief, RIS, Vendor Program Branch ate INSPECTION BASES AND SCOPE:
A. BASES: 10 CFR Part 21 and Appendix B to 10 CFR 50.
I I
B. SCOPE: Evaluate corrective action taken relative to internittent failures, review the results of tests performed on three failed transmitters which were returned from Fermi-2, review the design and manufacture of transmitters to ascertain similarities and differences when compared to the products of other manufacturers which have experienced set point drift.
PLANT SITE APPLICABILITY: Fermi-2 (50-341) and River Bend (50-458).
l 8704130438 870408 PDR GA999 EMVROSM 99900271 PDR
ORGANIZATION: ROSEM0UNT, INCORPORATED EDEN PRAIRIE, MINNES0TA REPORT INSPECTION RESULTS: PAGE 2 of 8 NO.- 99900271/87-01 A. VIOLATIONS:
None.
B. NONCONFORMANCES:
None.
C. UNRESOLVED ITEMS:
None.
D. FINDINGS AND OTHER COMMENTS:
- 1. Backaround Information Rosemount manufactures the following instruments:
- a. Transmitters Transmitters to measure pressure (absolute, gage and differen-tial), flow, and level,
- b. Trip / Calibration Systems Trip / Calibration System (TCS) is a multichannel signal condition-ing system with a built-in calibration capability.
- c. RTDs RTDs manufactured by Rosemount have not been qualified to IEEE-323 and IEEE-344 reouirements.
- 2. Principle of Operation The Rosenount transmitters have a variable capacitance sensing element, the delta cell. Process pressure is transmitted through an isolating diaphragm and silicene oil fill fluid to a sensing diaphragm in the center of the delta cell. The reference pressure is transmitted in like manner to the other side of the sensing diaphragm. The position of the sensing diaphragm is detected by the capacitance plates on both sides of the sensing diaphragm.
Differential capacitance between the sensing diaphragm and the capacitor plates is converted to a 2-wire 4-20mA DC signal in transmitters qualified for installation in nuclear power plants.
- ORGANIZATION: ROSEMOUNT, INCORPORATED EDEN PRAIRIE, MINNESOTA REPORT INSPECTION NO.: 99900271/87-01 RESULTS: PAGE 3 of 8
- 3. Failures Reported at Fermi-2 The Detroit Edison Company (DEC) issued Licensee Event Report (LER)
No. 29 dated September 29, 1986 which documented the following three Rosemount transmitter failures at the Fermi-2 nuclear facility.
- a. On August 5, 1986, a model 1151 DP 7E pressure transmitter installed in the main steam line failed downscale. The trans-nitter was replaced,
- b. On August 23, 1986, a model 1153 DB6RC flow transmitter installed in the Division I High Pressure Core Injection line failed downscale, while the plant was in operational condition 2 (startup) with reactor power under 3 percent and reactor pressure at 910 psig. The transmitter monitors steam flow to the HPCI turbine and provides, via the trip unit, an isolation signal when predetermined flow rates are exceeded. While trouble shooting the failed transmitter, the unit began to operate properly for no apparent reason.
The transmitter was returned to service. On August 26, 1986, the same transmitter failed low. The transmitter was replaced with an identical 1153 086 transmitter,
- c. Additionally, a model 1153 GB8RC pressure transmitter installed in the Residual Heat Removal pump discharge system failed offscale low.
DEC sent the three failed transmitters to Rosemount to analyze the cause of failures. In the interim, DEC imposed administrative controls on their operations personnel requiring them to check all trip units once per shif t to detect any potential off-scale conditions. The operators were informed that a transmitter could fail in such a manner that the trip point is not reached and the offscale condition would otherwise go unnoticed.
Posemount evaluated the three transmitters returned by Fermi-2 with the following results:
The model 1153 GB pressure transmitter installed in the residual heat removal pump discharge line failed intermittently off-scale icw.
The model 1151 DP pressure transmitter installed in the main steam line failed intermittently off-scale high. The model 1153 DB pressure transmitter installed in the high pressure conlant injection line failed intermittently off-scale low.
ORGANIZATION: ROSEM0UNT, INCORPORATED EDEN PRAIRIE, MINNES0TA REPORT INSPECTION N0.: 99900271/87-01 RESULTS: PAGE 4 of 8 Rosemount technicians bench tested each transmitter and determined that they performed satisfactorily. The transmitters were dis-assembled and the sensor modules were removed. The sensor cells were removed from the modules, cut open and the internal surfaces were inspected under a high powered microscope. Small electrically conductive particles were found in all three cells. The sensor modules were replaced and each transmitter passed a complete acceptance test procedure.
Rosemount concluded that impurities in the sensor cell may have caused the intermittent failures. Corrective actions taken to inform customers of the potential problem and to prevent recurrence are discussed in paragraphs 4 and 5 respectively.
4 Corrective Action Taken By Rosemount Rosemount issued a letter dated July 24, 1986 to all their customers based en reports received that a few transmitters demonstrated an intermittent syndrome (syndrome). The syndrome was characterized by an instantaneous output signal shift, offscale around 28mA high or 2.8mA low. This output shift was not typically in response to a shift in actual process pressure. This condition continued until it was corrected by any one or all of the following: removal of input pressure, removal of power supply voltage, and continued operation in the process. Once corrected, the transmitter and the instrument loop performed within specification. However, the offscale output may reoccur later.
The letter explained that the syndrome is exhibited in transmitters that:
- a. Measure pressure in higher ranges, i.e., 150 psi differential pressure or 1000 psi static line pressure or greater.
- b. Are mounted on mechanically or pneumatically noisy t
lines such as main steam line or pressurizer l pressure line.
- c. Have failed previously or are mounted in a location l
where a previous failure occurred.
- d. Have been in service less than one year.
ORGANIZATION: ROSEM0UNT, INCORPORATED EDEN PRAIRIE, MINNESOTA REPORT INSPECTI0h N0.: 99900271/87-01 RESULTS: PAGE 5 of 8 Rosemount personnel believe that the principal cause of the syndrome is accumulation of dirt particles in the sensing lines at the orifice entrances or valves ups,tream of the transmitters. Inadequate post-construction cleaning of the sensing lines and improper operation of snubbers supporting the impulse sensing lines are considered possible contributors to the dirt accumulations. Some of the remedial actions taken to successfully correct the above problems were as follows:
- a. Removal of snubbers from impulse lines connected to the transmitter,
- b. Cleaning and adjustment of check valves in the impulse lines,
- c. Cleaning and flushing of the impulse lines,
- d. Grounding the transmitter housing to station instrument ground.
Rosemount requested recipients of the letter to furnish information of their experiences, if any, on transmitters which exhibited this syndrcme in their plants. Rosemount issued a followup letter dated November 25, 1986 stating that they received only two responses to their letter dated July 24, 1986. The letter stated the responses contained no additional information, and Rosemount made some manufacturing process changes, and additional application related research was in progress to further evaluate the problem.
- 5. Corrective Action in Manufacturing Rosemount's corrective actions consisted of the following changes in the manufacturing processes to eliminate particulates in the sensor cells,
- a. Drawing 01153-0265, titled "Diaphragn Center," was revised on July 17, 1986 to require the parts to be clean and free of chips and burrs under 30X magnification. This note applies to sheets 2 and 3 of the drawing, which show the diaphragms for different ranges. Furthermore, during the machining of the groove in the sensor cell's center diaphragm, adjustments were made in the machining operation. Changes were made on the sharpness of the cutting tool, the speed of the tool movement, and the angle of the tool movement.
ORGANIZATION: ROSEMOUNT, INCORPORATED EDEN PRAIRIE, MINNES0TA REPORT INSPECTION NO : 99900271/87-01 RESULTS: PAGE 6 of 8
- b. Drawing 01153-3182 which describes the cleaning of the center diaphragm and the capacitor plate was revised on September 3, 1986 to require ultrasonic cleaning for 5 minutes.
- c. Drawing 01153-3181 which is used to check adhesion of aluminum vapor to the glass substrate plate was revised on July 9,1986, to require 100 percent inspection of the plates instead of the previous sampling insrectinns. The procedure requires a short piece of clean cellophane tape to be stuck to the deposition area of the capacitor plate, pressed firmly for maximum adhesion and slowly pulled free. The capacitor plate is then visually examined for gaps in the deposited material and for traterial sticking to the tape. The plate is considered unacceptable if appreciable material sticks to the tape. A l discrepancy report (DR) is written and forwarded to the vapor deposition department to take appropriate corrective action.
- 6. Failure Reported at River Bend On December 23, 1986, Gulf States Utilities Company reported that while the River Bend facility was at 100", power, a tredel 1152 DPSE transmitter installed in the Reactor Core Isolation Cooling (RCIC) steam line failed downscale. This caused an actuation to isolate the steam line to the RCIC steam turbine. The transmitter was replaced and the plant continued operation. The failed transmitter was shipped to Rosemount for failure analysis. At the time of the inspection, Rosemount had received the transmitter, but had not disassembled it because they did not receive a certificate that the transnitter was free from contamination.
- 7. Quality Control Inspections The inspector reviewed the quality control (QC) inspections to determine if the changes in the manufacturing process were being verified and determined that Drawing 01153-3399 dated July 16, 1986 requires the following attributes to be inspected by QC on 100 percent of the center diaphragm and cell halves:
- a. Under 30X magnification the parts are to be inspected for machining burrs, broken off vapor deposition, or other contamination.
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ORGANIZATION: ROSEMOUNT, INCORPORATED EDEN PRAIRIE, MINNESOTA REPORT INSPECTION NO.: 99900271/87-01 RESULTS: PAGE 7 of 8
- b. The machined grooves of the center diaphragms are to be inspected to determine if metal filings are present.
- c. The locations of ceramic insert holes and fill tube holes on cell halves are to be inspected to determine whether broken-off vapor deposition are present. Components with adverse findings are to be rejected along with a DR to document the findings.
- 8. Observation of Manufacturing Activities The inspector accompanied by Rosemount personnel toured the facilities and observed the following activities:
- a. Receipt inspections for mechanical components,
- b. Receipt inspections for electrical components.
- c. Manufacturing of various subcomponents.
- d. Retention of material traceability,
- e. Testing of sub-assemblies.
- f. Testing for linearity on assembled electronic components.
The inspector determined that established procedures were being followed, OC inspections were being performed as required, and the measuring instruments had valid calibration stickers.
- 9. Review of 10 CFR Part 21 Procedure The inspector reviewed the procedure to implenent 10 CFR Part 21 requirements and determined that there was no provision to document that failure evaluations were reviewed for Part 21 reportability.
The procedure required that Rosemount inform the user and the user evaluate the safety significance of a deviation since they were knowledgeable of the application. Rosemount had issued a letter dated July 24, 1986 stating that some transmitters exhibited an intermittent syndrome by failing either downscale low or upscale high and requested recipients to provide additional information on their experience. However, documentation of the evaluations failed to indicate that intermittent problems reported by users were evaluated by Rosemount management personnel prior to issuance of the letter dated July 24, 1986. Rosemount's procedure OIP-9N, Revision C, titled " Returned Nuclear Products" defines the policy and methods for processing of products returned from nuclear power plants and requires a failure analysis to be performed. However,
ORGANIZATION: ROSEMOUNT, INCORPORATED EDEN PRAIRIE, MINNES0TA REPORT INSPECTION RESULTS: PAGE 8 of 8 NO.: 99900271/87-01 neither the Part 21 procedure nor the procedure on returned products specifically required that failure analyses on returned products be reviewed for Part 21 reportability.Rcsemount representatives stated that they would revise the 10 CFR Part 21 procedure to require management officials to review the results of the failure analysis on returned products and document their evaluations on an attachment to the procedure QlP97N.
It should be noted that Rosemount, in a letter dated February 5, 1987, stated that this revision.to the Part 21 procedure had been implemented.
E. PERSONS CONTACTED:
R. G. LaSell, Manager, Nuclear Products Group R. Volsted, Supervisor, Nuclear Projects G. D. Anderson, Supervisor, Quality Assurance
- R. E. Reinerstein, Quality Assurance Representative W. Koch, Director, Ouality Assurance
- R. VonDerBloom, Project Engineer M. Schneider, General Consul J. Jensen, Corporate Attorney
- Denotes individuals not present at the exit meeting on January 29, 1987.
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