Phenix youth disease

The breakdown in Phenix operation is due to intermediate exchangers (between primary and secondary sodium). The secondary sodium intake and outflow are effected vertically through orifices situated at the top of the exchangers, and fitted with two encased concentric tubes: the reheated sodium flow out at the periphery, the cold sodium penetrates along the axis, a biological shielding sheath is inserted inside the annular space between both cylinders. The stresses resulting from successive shut down, start-up, and changes in the operation rate entailed the failure of the shell containing the secondary sodium that went up to the upper part of the exchanger, impregnating the insulator material and producing smoke emission. The plant was shut-down, and the damaged exchanger dismounting started. Emphasis is put on the fact that this fact should not, on other respects, delayed the development of Superphenix that is asked for lower performance than Phenix. Its most important improvements with regard to Phenix are concerned with the steam generators (cyclone separators) and the corrosion preventing mixtures (especially against denting)