Activities in Support to the Assessment of Steam Generator Bayonet Tubes, for GEN-IV Applications

The overall activity is aimed to verify the feasibility of the superheated steam double wall once through bayonet type steam generation. The work and the relative experimental campaigns will be focused on the single tube evaluation. It spans over three years. The main phases of the experimental campaigns are: -Individuate a candidate material as gap filler for the bayonet tube. -Verify the single tube performance in representative operating conditions. This report is the result of a collaboration between UNIPI-UNIROMA1 and ENEA. It is subdivided in seven sections. The first one points out the objectives and the framework of the activity. Section two describes the ALFRED SG and points out the results of the screening of candidate insulating materials to be placed in the bayonet tube, between the descendent feedwater and the superheated steam riser. In section three, the detailed assessment of the single tube performance by means of RELAP-5 is reported. Systematic comparison with the ANSALDO calculations are included. Section four focuses on the thermal hydraulic conceptual design of the heating power system of the Heavy liquid mEtal – pRessurized water cOoled tube facility (HERO). The section points out the geometry of a facility capable to test one 1:1 bayonet tube of ALFRED. RELAP-5 and FLUENT calculations are presented in this section. The preliminary PID of HERO is analyzed in section five. The status of advance of the Tubes for Powders facility (TxP) is discussed in the sixth section. Summary and conclusions are presented in the last section..