Dissolution Behavior of M5 Cladding in Hydrofluoric–Nitric Mixed Acid
M5 cladding has emerged as a prominent fuel cladding material due to its excellent corrosion resistance. The dissolution behavior of M5 cladding is critical in both the initial cleaning stage and the reprocessing of spent fuel cladding. This study investigated the dissolution of M5 cladding in hydrofluoric-nitric (HF-HNO<sub>3</sub>) mixed acid at varying concentrations. When the HF concentration exceeds 0.5 mol/L, the addition of strong oxidizing HNO<sub>3</sub> significantly reduces the dissolution rate. Moreover, HNO<sub>3</sub> effectively inhibits the HF-induced corrosion pitting, lowering surface roughness to 0.812 μm at a 1:5 ratio of HF:HNO<sub>3</sub>. In addition, a surface structural analysis reveals the dissolution mechanism of M5 cladding. The β-Nb precipitated in the mixed acid was oxidized to stable Nb<sub>2</sub>O<sub>5</sub> by HNO<sub>3</sub> while the M5 matrix surface was continuously oxidized to ZrO<sub>2</sub>. This passivation layer inhibits further dissolution, slowing the process and enhancing the uniformity of M5 cladding.
Authors
- Yue Sun (ORCID: https://orcid.org/0000-0003-3452-4219)
- Zhongwei Yuan (ORCID: https://orcid.org/0000-0002-8843-6698)
- Weifang Zheng (ORCID: https://orcid.org/0000-0002-7503-3603)
- Taihong Yan (ORCID: https://orcid.org/0009-0003-4002-4373)
- Ziqian Zhao (ORCID: https://orcid.org/0000-0002-4784-0440)
- Ying Chen (ORCID: https://orcid.org/0000-0001-7687-0676)
- Wei Zheng (ORCID: https://orcid.org/0000-0002-3143-4720)
- Fang Liu
- Yang Bai (ORCID: https://orcid.org/0009-0002-6148-7433)
Institutions
- China Institute of Atomic Energy (CN)
Publication Details
- Journal
- Materials
- Published
- 2024-11-25
- DOI
- https://doi.org/10.3390/ma17235771
- Primary Topic
- Nuclear Materials and Properties
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Key Research and Development Program of China