Caesium and Strontium Contamination on Nag 18/10l Stainless Steel Following Corrosion in Simulated Nitric Acid Reprocessing Liquor

Abstract

Contamination under reprocessing conditions was simulated by corroding NAG 18/10L stainless steel in 8 M HNO3 containing 0.5 mol L-1 caesium, 0.05 mol L-1 strontium. Atom probe tomography results found a nanoscale chromium-rich oxide layer with a chromium:oxygen ratio of 2:3 that contained 0.15 at% caesium and 1.04 at% strontium (95% CI [0.00, 0.40] and [0.71, 1.38] respectively). No contamination was found in the metal matrix away from the oxygen diffusion region (< 2 at% oxygen). An absorbed dose rate of 11.8 mGy hr-1 was estimated for adipose tissue at the centre of a hypothetical contaminated cubic vessel.

Keywords: Acid solutions (A), Stainless steel (A), atom probe (B), acid corrosion (C), intergranular corrosion (C), passive films (C)