Preliminary design and study of the indirect coupled cycle: CATHARE2 transient results

The gas cooled fast reactor (GFR) is one of the six reactor concepts selected in the framework of the Generation IV forum. The main characteristics of the CEA GFR concept are a 2400 MW core based on a ceramic pin type fuel as a reference, with an inlet temperature of 400 °C and an outlet temperature of 780 °C. The present study concerns an alternative design of the primary compression systems, assuming that the primary compressors are driven by the turbogenerators of the secondary circuits. This new system requires that the 3 shafts connecting the turbines and the compressors of the secondary circuits are also connected to their corresponding primary blowers, via longer shafts crossing the primary circuit vessel. aper presents the transient results obtained with the CATHARE2 code. The transients study concerns various severe depressurised situations caused by a large diameter pipe rupture. The results of the reference break accident confirm the first conclusions obtained with analytical considerations: the behaviour in LOCA situation seems satisfactory. Furthermore sensitivity simulations are performed involving aggravating events and design parameters.