Investigation of the thermal hydraulic and mechanical behaviour of double-walled bayonet heat exchanger tubes for liquid-metal cooled reactors


SCK•CEN Mentor

Van Tichelen Katrien
+32 14 33 80 06

SCK•CEN Co-mentor

Kennedy Graham
+32 14 33 80 28

Expert group

LBE Components and Experiments

Post-doc started


Short project description

MYRRHA is a flexible fast-spectrum pool-type research reactor cooled by Lead Bismuth Eutectic (LBE) under design at SCK•CEN, Belgium. Conceived as an accelerator driven system prototype, it is able to operate in sub-critical mode. Operating in critical mode, MYRRHA is identified as the European Technology Pilot Plant for the Lead-cooled Fast Reactor.

Primary heat exchangers (PHX) with double-walled tubes, using an innovative heat transfer design, are currently envisaged to be used in MYRRHA. These PHX must combine following contradictory requirements:

  • eliminate by design Polonium release as a consequence of steam tube rupture through the use of double walled tubes and monitoring of the inter-tube gap and
  • be sufficiently small in overall diameter to be able to be installed within the reactor vessel.

In interaction with industrial HX manufacturers, the MYRRHA primary system design (PSD) team is developing two conceptual designs of a double-walled PHX: one with LBE in the gap between the tube walls and one with co-extruded tubes. However, because of the innovative designs and the unique conditions presented by the LBE environment, there's large uncertainty in the thermal-hydraulic and mechanical behavior of the double-walled tubes. By mid 2016, first concepts by PSD will be ready. They will provide input for the LBE research team where dedidacted experiments on the thermal-hydraulic and mechanical behavior will be performed.




The objective of the proposed post-doc program within the LBE research team is to develop and apply a methodology for the experimental investigation of:

  • the overall heat transfer coefficient of double-walled PHX tubes
  • the mechanical behavior of these double-walled PHX tubes under high thermal loads from temperature gradients

For this purpose, one or more scaled test set-ups have to be developed, respecting the thermal-hydraulic and mechanical behavior in a limited-size tube bundle that is to be implemented in the COMPLOT facility.

Moreover, suitable experimental techniques have to be selected and implemented taking into account the limitations presented by the harsh LBE environment and the strong temperature gradients expected.

Finally, the experimental campaign should be performed and the experimental data should be analyzed to formulate correlations for heat transfer coefficients and guidelines for mechanical design that can be used by the design team.

The post-doc will receive support from the COMPLOT design engineer for the design and integration of the test section(s) in the existing experimental facility at SCK•CEN. The necessary provisions for coupling the test section(s) to a steam/water secondary loop are under preparation. The complete facility will be operational early 2018.