Corrosion of materials for steam generators of fast neutron, sodium cooled, reactors in sodium contaminated with sodium hydroxide

Corrosion phenomena liable to affect the steam-raising tubes in superheating nuclear reactors after accidental introduction of water has been studied. The tests done at 350 and 5500C in sodium contaminated with sodium hydroxide (up to 10%) for about 500 h have shown that ferritic steels suffer general corrosion. By contrast, the austenitic alloys examined may break by tensile stress-corrosion above a certain stress level and when a sufficient sodium hydroxide concentration is maintained for a sufficient length of time. (Auth.)