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Critical heat flux (CHF) testing with electrically heated fuel assemblies is a challenging task. High electrical power has to be precisely handled and quickly controlled when CHF occurs. Determining the onset of CHF requires sophisticated and robust measurement technology operating under high pressure and temperature.

The multifunctional Karlstein Thermal-hydraulic Test Loop (KATHY) is designed to determine the onset of CHF of electrically heated fuel assemblies, which are geometrically identical to real fuel assemblies. KATHY operates under full-scale conditions. The thermal-hydraulic conditions, such as pressure, temperature and mass flow, are kept constant during the CHF test performance while the power is slowly increased until CHF is reached. The extensive instrumentation with thermocouples inside the heater rods allows determining the axial and radial appearance of CHF inside the test bundle.

Your benefits

  • State-of-the-art test loop
  • More than 2,500 heater rods on stock
  • Test frequency per test 5 to 10 minutes
  • Benchmarked against OMEGA Loop (CEA), ATLAS Loop (GE) and HTRF Loop (CU)
  • Integration and access to the Thermal-hydraulic Platform
  • Accredited test and inspection body
  • Accepted by ILAC
  • Open to external customers

Interested in KATHY Loop for Critical Heat Flux Tests?


AREVA’s Thermo-hydraulic Platform qualified as test and inspection body

AREVA NP Germany