PLANT-ORIENTED INSTRUMENTATION FOR HYDROGEN DETECTION IN SODIUM FOR FAST BREEDER REACTORS

Abstract

This paper discusses the plant-oriented instrumentation developed for a solid electrolyte-based hydrogen sensor. The sensor detects any event of steam leak at the steam generator of fast breeder reactors, by continuously monitoring the hydrogen concentration in secondary sodium. A specially designed in situ preamplifier measures the electromotive force (EMF) generated by the sensor and the temperature of sodium. After digitizing, these signals are transmitted to a signal-processing unit. A microcontroller-based signal-processing unit receives the signals and calculates the hydrogen concentration in parts per billion (ppb). The instrument measures hydrogen concentration in the range of 50 to 1000 ppb. It provides the analog signal of the hydrogen concentration to the plant computer for logging purposes. The instrumentation makes surveillance checks on instrument performance and provides a system healthiness status to the plant computer. These instruments are installed in a fast breeder test reactor (FBTR) in Kalpakkam, India, in other sodium experimental facilities of Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, and in a fast breeder reactor in Phenix, France. The long-term performance of these instruments is found to be very good.