ML20071E268
| ML20071E268 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/25/1983 |
| From: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, L-83-96, NUDOCS 8303150165 | |
| Download: ML20071E268 (3) | |
Text
o P. O. BOX 14000, JUNO BE ACH, F L 33408 FLORIDA POWER & LIGHT COMPANY February 25, 1983 L-83-96 ww a
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Mr. James P. O.'Reilly
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'I Z Regional Administrator, RegionII N*
U. S. Nuclear Regulatory Commission 1.,'y 101 Marietta Street, Suite 3100 3
Atlanta, Georgia 30303 u:
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Dear Mr. O'Reilly:
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cc RE:
St. Lucie - Unit 2 Docket No. 50-389, IOCFR50.55(e),82-030 I W BARTON PRESSURE TRANSMIMERS On December 21, 1982 Florida Power and Light notified the NRC of a potential 10CFR50.55(e) condition existing at St. Lucie Unit #2 site involving ITT Barton pressure transinitters. Attached please find our final resolution of this issue.
Very truly yours, i
Robert E. Uhrig Vice President Advanced Systems & Technology
.. i U r 3 r er vy 7/f Af/
8303150165 830225 PDR ADOCK 05000389 PEOPLE.. SERVING PEOPL E
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SUMMARY
Testing of ITT Barton pressure transmitters revealed that they could exhibit signal drift uncertainties larger than design specificatier.s.
These unexpected uncertainties are believed to be the result of (1) te perature conditioninc (stress relieving) which occurs only during initial use of the transmitters and (2) intermittent current leakage through a metallic washer at elevated temperatures.
In addition to these uncertainties, four narrow rance (0-750 psia) pressure transmitters exhibited unexpected " pressure shift" uncertainties due to use in the 0-750 psia range after operating at pressures (2300-2400 psia) approxirating those for normal operation.
If the above uncertainties had gone undetected it could have been possible to experience delayed or unexpected safety system actuation or leakage of radio-active coolant through Shutdown Cooling System (SDCS) relief valves.
Therefore, 7
the anomalous behavior of the ITT Barton pressure transmitters is reportable with respect to 10CFR50.55 (e).
II DESCRIPTION The affceted pressure transmitters (Models 763 and 764) can exhibit temperature drift uncertainties about 1.5% larger than the design criterien (+0.5%) for 0
temperatures up to 130 F.
The four narrow range transmitters also exhibited
" pressure shift" uncertainties of about 3% in addition to the above " drift" uncertainties. For accident temperature conditions (4200F), the Model 763 and 764 transmitters can exhibit uncertainties about 3% - 4% above the ITT Barton design criterion (+ 10%).
The affected pressure transmitters provide input for the following applications:
MODEL TAG 1RNBER DESCRIPTION 763 PT-1103, -1104, SDCS Initiation Interlock, Coolant
-1105, -1106 System Pressure-Temperature Limit Compliance 763 PT-1102A, B, C, D Pressurizer Pressure (Thermal Margin-Low Pressure Trip) 763 PT-8013A, B, C, D Stean Generator Presstre 763 PT-8113, 8123 Steam Generator Pressure on Hot Shutdown Panel (Post Accident Monitoring) 763 PT-1107, 1108 Wide Range Pressurizer Pressure (Post Accident Monitoring) 763 PT-21-8A, P-21-88 Intake Cooling Water Header Pressure 764 P-1158, -1168, -1178 Component Cooling Water Plow
-1188
e Y
764 LT-9013A, B, C, D Steam Generator Water level LT-9023A, B, C, D 764 LT-1104, -1105 Pressurizer Level on Hot Shutdown Panel (Post Accident Monitorina) 764 LT-1110X, Y Pressurizer Water Level (Low Level Heater Cutout) 764 LT-9113, -9123 Steam Generator Water level on Hot Shutdown Panel (Post Accident Monitoring)
III CORRECTIVE ACTION The four narrow range transmitters (tag number PT-1103, -1104, -1105, and 1106) are being replaced with Rosemount transmitters that have lower uncertainties for normal conditions relative to the ITT Barton transmitters. The remaining transmitters will be calibrated after appropriate temperature conditioning to
'obtain acceptable uncertainties.
Also, if the safety system setpoints being generated for the higher uncertainties indicate that it is necessary to reduce the uncertainty resulting from current leakage, the metallic washer nay be replaced with a fiberglass washer.
IV SATETY IMPLICATION If all of the four narrow range transmitters indicated reactor coolant system (RCS) pressure based on the highest expected uncertainties, it would be possible fcr the operator to initiate the SDCS at hicher than expected RCS pressures.
This could result in seme leakage of radioactive coolant from the SDOS relief valves.
Even with the higher uncertainties for these four transmitters, the low temperature overpressure protection system and power-operated relief valve setpoints would ensure that the BCS pressure-temperature linits are not exceeded.
If uncertainties occurred which were greater than those assumed in the generation of the safety system setpoints, delayed or unexpected safety system actuations could occur.
Therefore, there exists the potential for an impact on safe operation of the plant.
However, this impact would not he expected to be signif-icant since the highest uncertainties would have been only a few percent (see Section II) above ITT Barton design criterion.
V CCNCLUSION This issue' is reportable with respect to 10CFR50.55(e).
This report is final and ccmpletes requirements for reporting to the NRC.