Mass transport of oxygen and corrosion products in LBE cooled systems

Gladinez Kristof

Promoter

Heynderickx Geraldine, (UGent), geraldine.heynderickx@ugent.be

SCK•CEN Mentor

Rosseel Kris
kris.rosseel@sckcen.be
+32 14 33 80 05

SCK•CEN Co-mentor

Lim Jun
jun.lim@sckcen.be
+32 14 33 80 15

Expert group

Conditioning and Chemistry Programme

PhD started

2015-10-01

Short project description

In LBE cooled systems, oxygen and corrosion products need to be controlled to avoid formation of solid precipitates which could hamper long-term operations.

An appropriate LBE coolant purification system to remove dissolved or solid impurities should be developed and validated for the safe operation of LBE cooled nuclear systems. Solid impurities are chemically stable or metastable particles composed of metals or metal oxides and can be filtered from the LBE purely by mechanical filtering. Dissolved impurities, on the other hand, cannot be filtered from LBE solely by mechanical methods, but need to be precipitated to capture them. This is typically achieved in a cold-trap where the temperature of the LBE is reduced to below the solubility limit of the impurity.

However, the cold trap technology for LBE cooled system has not been explored yet.

Objective

In this PhD topic, numerical simulation tools and experiments will be combined to study the mass transfer and trapping/deposition of oxygen and impurities (mainly corrosion products) in non-isothermal LBE cooled systems.  This should result in design recommendations for an LBE filter and cold trap - or a combined filter/cold trap - that can be implemented in the MYRRHA conditioning system.

To develop an efficient impurity control system, experiments will be performed in the MEXICO chemistry control loop in parallel with numerical simulations.

Specific objectives are the following:

  • Mass transport and trapping of oxygen:
    • Determination of  cold trapping kinetics and efficiency for oxygen (as PbO) by monitoring the differential pressure and oxygen concentration over the cold trap/filter in an LBE loop
    • Establish the link between the pressure drop over the cold trap and the amount of PbO accumulated in the trap by comparing experimental results and numerical simulations.
  • Mass transport of and trapping of Ni
    • Measurement of cold trapping/filtering kinetics and efficiency for Ni
    • Comparison with numerical simulations to study long-term evolution of the Ni content in an LBE loop.

In the second phase of this PhD project, the results will be used to design a cold trap/filter which will be installed in a scaled mock-up of the MYRRHA conditioning system and which is to be connected as an external loop to the existing E-SCAPE facility. The final objective is implementing the mass transfer of oxygen and corrosion products in the thermal-hydraulic model of E-SCAPE and validation of this model against experimental results.