Development of a Sodium Ionisation Detector for Sodium-to-Gas Leaks

摘要

A sensitive sodium-to-gas leak detector has been indigenously developed for use in liquid metal cooled fast breeder reactor. The detector relies on the relative ease with which sodium or sodium containing compounds can be thermally ionized compared with other possible constituents in a carrier gas (nitrogen, oxygen, water vapour etc.) and is therefore called Sodium Ionization Detector (SID). It is designed to function and operate at atmospheric pressure unlike conventional ionization gauges which operate at vacuum only. Different sensor designs and their responses to different sodium aerosol concentrations in nitrogen carrier gas of commercial and special quality were investigated. The results of these experiments have been summarised. One of the detector designs demonstrated a sensitivity better than 0.3 nanogram of sodium per cubic centimetre of gas for a signal to background ratio of 1:1. The detector's selective response to aerosols from sodium fire has shown its usefulness to detect leaks in operating sodium loops. (Atomindex citation 12:605584)