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Title: Long term out-of-pile thermocouple tests in conditions representative for nuclear gas-cooled high temperature reactors

Conference ·
 [1];  [2]; ;  [1]
  1. European Commission, Joint Research Centre, Inst. for Energy, P.O. Box 2, NL-1755 ZG Petten (Netherlands)
  2. THERMOCOAX SAS, BP 26, Planquivon, F-61438 Flers Cedex (France)

During irradiation tests at high temperature, failure of commercial Inconel 600 sheathed thermocouples is commonly encountered. To understand and remedy this problem, out-of-pile tests were performed with thermocouples in carburizing atmospheres which can be assumed to be at least locally representative for High Temperature Reactors. The objective was to screen those thermocouples which would consecutively be used under irradiation. Two such screening tests have been performed with a set of thermocouples embedded in graphite (mainly conventional Type N thermocouples and thermocouples with innovative sheaths) in a dedicated furnace with helium flushing. Performance indicators such as thermal drift, insulation and loop resistance were monitored and compared to those from conventional Type N thermocouples. Several parameters were investigated: niobium sleeves, bending, thickness, sheath composition, temperature as well as the chemical environment. After the tests, Scanning Electron Microscopy (SEM) examinations were performed to analyze possible local damage in wires and in the sheath. The present paper describes the two experiments, summarizes results and outlines further work, in particular to further analyze the findings and to select suitable thermocouples for qualification under irradiation. (authors)

OSTI ID:
22039855
Resource Relation:
Conference: ANIMMA 2011: 2. International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications, Ghent (Belgium), 6-9 Jun 2011; Other Information: Country of input: France; 5 refs.; IEEE Catalog Number: CFP1124I-CDR
Country of Publication:
United States
Language:
English