Continuous monitors for tritium in sodium coolant and cover gas of an LMFBR

Abstract

Continuous monitors for tritium in the sodium coolant and the cover gas of a fast breeder reactor have been developed. The sensor for the monitors consists of a thin nickel membrane which permits the diffusion of tritium into an argon sweep gas containing 1 to 5% hydrogen. The tritium content of the sweep gas leaving the sensor is determined by disintegration-rate counting in an ionization chamber. The monitors for sodium are sensitive to 0.04 nCi of tritium/ g of sodium (1 curie = 2.06 x 10/sup 19/ atoms of tritium); for the cover gas monitors, the sensitivity level is 0.6 x 10/sup 11/ atoms of tritium/liter of gas. For comparison, the typical tritium content of the primary sodium in EBR-II is 50 nCi/g, and in the primary cover gas it is 3 x 10/sup 12/ atoms/liter. 12 references. (auth)