Fuel Cladding Corrosion Testing in Simulated Superheat Reactor Environment Phase I. General Corrosion Type 304 Stainless Steel

Type 304 stainless steel cladding material has been corrosion tested under heat transfer conditions at metal temperatures up to 1300°F in specially constructed out-of-pile superheat facilities. The hydrogen and oxygen contents of the steam have been controlled to simulate that found in boiling water reactor type systems. Good corrosion resistance and low metal release to system up to metal temperatures of 1100°F were experienced with an expected pattern of an initially high corrosion rate that decreased to a lower constant rate with time up to 4500 hr. A compositionally disturbed layer developed adjacent to the scale in the 1100°F to 1300°F metal temperature range on the heat transfer specimens. The layer continued to grow with time but had little effect on the corrosion rate within the 2500 hours of testing.