PANAS – Experimental and theoretical investigations of generic thermal hydraulic issues of passive safety systems


PANAS – Experimental and theoretical investigations of generic thermal hydraulic issues of passive safety systems

Schuster, C.; Lippmann, W.; Hampel, U.; Walther, M.; Leyer, S.

To guarantee the nuclear safety which means keeping the radioactivity inside the fuel rods it is necessary to remove the decay heat in all circumstances of normal and abnormal operation situations. Decay heat removal systems of the present reactor fleet are based on active components like pumps, motor driven valves, electrically I&C etc. They depend on the supply of additional energy which could fail how it was imposingly demonstrated in Fukushima. Virtually all new reactor designs of generation 3+ are characterized by the implementation of various passive safety components.
Passive Residual Heat Removal (PRHR) systems use heat transfer induced density differences to provide sufficient driving forces to establish a system mass flow in natural circulation loops of various configurations. Thus in order to design and model the system performance the determination of the heat transfer resistances is a crucial part since it influences the quality of calculation results on two sides: the heat transferred to the coolant as well as the mass flow of the coolant. Today’s state-ofthe-art PRHR systems use mostly the phase transition between the liquid and the vapor phase of the coolant to maximize the system mass flow and thus the performance. Precondition for the adoption of PRHR systems in nuclear reactors is the verification of the functional capability in all operation modes of the power plant. Therefore a comprehensive experimental work at different mockup scales combined with theoretical investigations (e. g. CFD and system codes) has to be undertaken.

Keywords: Passive safety systems; heat transfer; CFD

  • Lecture (Conference)
    49th Annual Meeting on Nuclear Technology (AMNT 2018), 29.-30.05.2018, Berlin, Deutschland
  • Contribution to proceedings
    49th Annual Meeting on Nuclear Technology (AMNT 2018), 29.-30.05.2018, Berlin, Deutschland

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Publ.-Id: 27115