This paper studied the release of iodine from lead vanado-iodoapatite (I-APT, Pb_9.85(VO₄)₆I_1.7), a potential nuclear waste form for the radioactive waste element of I-129, which can be enhanced when crevice corrosion of stainless steel (SS) occurring nearby. Reference corrosion studies of I-APT were performed in different bulk solutions including DI water, 0.6 M and 6 M NaCl, and 0.1 M HNO₃ without metal crevice corrosion interactions. The localized enrichment of Cl⁻, one of the major consequences of SS crevice corrosion, was found to be the decisive factor that led to the enhanced release of iodine. A surface alteration layer consisting of a mixture of nanocrystalline I-APT and Cl-rich apatite (Cl-APT) formed on I-APT surface. Meanwhile, large Cl-APT crystals formed at the crevice mouth on the I-APT surface. This study reveals a new near-field corrosion mechanism for ceramic waste forms when they are exposed to aggressive local corrosive conditions created by the electrochemical reactions of nearby metals. The insight gained in this study could be beneficial for a more accurate prediction of waste form degradation.

本文研究了钒铅-碘磷灰石铅（I-APT，Pb _9.85（VO ₄）₆ I _1.7）中碘的释放，这是I-129放射性废物元素的潜在核废物形式，当缝隙腐蚀时可以增强的不锈钢（SS）发生在附近。I-APT的参考腐蚀研究在不同的本体溶液中进行，包括去离子水，0.6 M和6 M NaCl和0.1 M HNO ₃，且没有金属缝隙腐蚀相互作用。氯的局部富集^-SS缝隙腐蚀的主要后果之一是导致碘释放增加的决定性因素。表面蚀变层，由在I-APT表面形成的纳米晶I-APT和富Cl磷灰石（Cl-APT）的混合物组成。同时，大的Cl-APT晶体在I-APT表面的缝隙口处形成。这项研究揭示了一种新的近场腐蚀机制，适用于陶瓷废料形式，当它们暴露于附近金属的电化学反应所产生的侵蚀性局部腐蚀条件时。在这项研究中获得的见识可能有助于更准确地预测废物形态的退化。