Cooling and Protecting Fast Reactors: Clarification of Complex Thermal Hydraulic Phenomena in Fast Reactor by a Sodium Experiment
—Demonstration of a reliable decay heat removal system for sodium cooled fast reactors and enhancement of the prediction accuracy of the numerical simulation for its evaluation—

Within the framework of the ongoing research cooperation program with the French Alternative Energies and Atomic Energy Commission (CEA) to promote development of sodium cooled fast reactor, the Japan Atomic Energy Agency has conducted a sodium experiment using the sodium facility（PLANDTL-2）installed in its Oarai Research and Development Institute. This experiment succeeded in demonstrating the effectiveness of a decay heat removal system that utilizes a heat exchanger installed in the upper plenum of a reactor vessel, as well as in obtaining experimental data that would considerably enhance the accuracy of its numerical simulation.

From now on, JAEA will perform the validation of the numerical simulation model using the obtained data and strive for further improvement of the prediction accuracy so that the demonstration of technologies, so far relied on mock up experiments, can be replaced by highly reliable numerical simulation in the future. That would enable significant reductions in development costs related to the construction and operation of large full-scale experimental facilities.