Small sodium-to-gas leak behavior in relation to LMFBR leak detection system design

The paper discusses various aspects of sodium-to-gas leaks which must be considered in the design of leak detection systems for LMFBR's. Attention is focused primarily on small weeping type leaks in the primary system environment. Corrosion rates of steels in fused sodium hydroxide and corrosion damage observed at the site of small leaks lead to the conclusion that the sodium-gas reaction products could attack the primary hot leg piping at rates up to 2 μm (0.08 mils) per hour. Based on theoretical considerations of the corrosion mechanism and on visual observations of pipe topography following small sodium leak tests, it is concluded that pipe damage will be manifested by the formation of small detectable leaks prior to the appearance of large leaks