Corrosion Behavior of Mild Steel Alloy A537 Used As Canister Material for Nuclear Waste Storage

Abstract

The interaction between mild steel nuclear waste storage containers and technetium ions is not well understood. Technetium is often found as an oxidized pertechnetate (TcO 4 -) anion at nuclear waste storage sites. This study is aimed at identifying whether TcO 4 -anions present a corrosion risk to mild steel nuclear waste storage tanks. The interaction of mild steel alloy A537 class 1 with rhenium, a technetium surrogate, was studied. Potentiodynamic polarization tests evaluated electrochemical behavior and the surface morphology was studied using scanning electron microscopy and optical microscopy. Potentiodynamic polarization experiments were conducted in 1.0M NaNO 3 + 0.1M NaOH and 1.0M NaNO 3 + 0.1M NaOH + 0.02M NaReO 4 . Three different temperatures were used in testing, namely, (i) ambient temperature, (ii) 50 o C and (iii) 80 o C. Sodium perrhenate was observed to inhibit the corrosion of the mild steel A537 samples. However, corrosion rates were found to increase with increasing temperatures both in the presence and absence of perrhenate.

Electrochemical Study of Metallic Rhenium in Methanol Acidic Aqueous Solutions

“…Rhenium is resistant to seawater corrosion and this metal has slow corrosion reaction in hydrogen and inert atmospheres at elevated temperatures (33). In addition, soluble oxide increased the corrosion resistance in the mild steel A537 (14). However, there are few studies of rhenium corrosion aqueous chloride media (3,18) and our study reported new data.…”

Internal heat source in the vadose zone: A comprehensive exploration through theoretical spectral analysis and practical application into thermal diffusivity and hydraulic flux in a Quaternary soil water layer

“…In the vadose zone-the unsaturated layer above the water table-this decay heat affects subsurface thermal dynamics, altering temperature distribution, moisture content, and other thermal properties. Notably, at the Hanford site, leakage of liquid nuclear waste into the vadose zone has resulted in significant contamination from radioactive substances such as caesium, strontium, and iodine, representing some of the highest concentrations of these chemicals in the United States (Grant, 2012). A thorough understanding of heat transfer is essential to prevent accidental releases of radioactive materials from conventional shallow disposal sites.…”