In-sodium hydrogen detection in the phenix fast reactor steam generator: a comparison between two detection methods (May 2009)

In a Sodium Fast Reactor (SFR), due to the necessity to reduce the probability of occurrence of water ingress in the Steam Generator Unit (SGU), the availability of a reliable detection system is essential. Several concepts are available: a diffusion nickel membrane with a mass spectrometer is worthwile set-up on reactors. Nevertheless, it requires a periodical calibration and an important maintenance. A new electrochemical hydrogen-meter, developed by IGCAR (India) has been developed and demonstrated attractive properties as sodium-water detection system. Within the frame of IGCAR-CEA collaboration on SFR Safety, it was decided to set-up such apparatus on an intermediate loop of PHENIX, prior to its shut-down. The results obtained have shown clearly that this instrumentation is of high interest for the safety of operation, nevertheless new tests are required to validate this new option, and particularly to characterize the influence of sodium temperature and to define a calibration methodology.