A Review of Corrosion of Titanium Grade 7 and Other Titanium Alloys in Nuclear Waste Repository Environments

Long-Term Immersion Testing of Alloy 22 and Titanium Grade 7 Double U-Bend Specimens

“…Crack length vs. time was monitored in-situ using a reversing direct current (DC) potential drop technique. The crack growth rate was approximately 1.3 × 10 -11 m/s [15,16].…”

“…The critical crevice corrosion temperature for Alloy 22 and Ti Gr 7 in ferric chloride solutions (ASTM G 48) are 70°C and ~200°C respectively [5][6][7]. Electrochemical studies have shown that Alloy 22 had high crevice repassivation potentials and that the presence of nitrate and other anions inhibit the occurrence of crevice corrosion [8,9].…”

Failure model and Monte Carlo simulations for titanium (grade-7) drip shields under Yucca Mountain repository conditions

“…However, Ti alloys are potentially susceptible to hydrogen-induced cracking (HIC) as a consequence of H absorbed during GC [2]. Enhanced hydrogen absorption could occur if Ti was subjected to a short period of crevice corrosion [3], but this is not expected for the Pd-containing or Ru-containing a-alloys proposed for DS fabrication [4][5][6].…”

The Long-Term Corrosion Test Facility at Lawrence Livermore National Laboratory

“…The primary purpose of the outer wall of the container Alloy 22 is to provide protection against corrosion. Alloy 22 (N06022) was selected for the corrosion resistant barrier of the waste packages because it is well known commercially for its excellent corrosion behavior in aggressive environments [2][3][4]. Because of its high Cr content, Alloy 22 remains passive in most industrial environments and thus, has an exceptionally low general corrosion rate.…”

“…Welding between Ti Gr 7 and Ti Gr 29 will be done using Ti Gr 28 (R56323). The presence of the drip shield will guard the waste packages against water seepage and rock fall from the drift walls [2][3][4]. …”