Oxidation characteristics of lead-alloy coolants in air ingress accident
Oxidation characteristics of lead-alloy coolants in air ingress accident
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DOI：
10.1016/j.egypro.2017.09.473
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
M. Kondo;N. Okubo;E. Irisawa;A. Komatsu;N. Ishikawa;Teruya Tanaka
中科院分区：
文献类型：
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作者：
M. Kondo;N. Okubo;E. Irisawa;A. Komatsu;N. Ishikawa;Teruya Tanaka
通过热力学考虑和不同化学成分的铅合金静态氧化实验，研究了快堆进气事故中铅（Pb）基冷却剂的化学行为。铅铋 (Pb-Bi) 合金的静态氧化测试结果表明，由于在 773K 空气中优先形成 PbO，合金中的 Pb 被耗尽。 Bi 不参与该氧化过程。由于Pb的贫化，合金中Bi富集后形成Pb-Bi氧化物和Bi2O3。静态条件下液态LBE上形成的氧化层厚度约为1mm。合金的氧化速率远大于钢的氧化速率，并且随合金中Pb浓度的升高而增大。当合金中的Pb浓度变低时，Pb-Bi合金与不锈钢的相容性变差，因为合金中的Bi成分促进了溶解型腐蚀。 Pb-Li 合金在形成 Li2PbO3 和 Li2CO3 时被氧化。然后，Li从合金中耗尽。进风事故中冷却剂系统中氧浓度升高后，可在反应堆系统低温区生成冷却剂的这些氧化物。
The chemical behaviors of lead (Pb) based coolants in the air ingress accident of fast reactors were investigated by means of the thermodynamic considerations and the static oxidation experiments for Pb alloys at various chemical compositions. The results of the static oxidation tests for lead-bismuth (Pb-Bi) alloys indicated that Pb was depleted from the alloy due to the preferential formation of PbO in air at 773K. Bi was not involved in this oxidation procedure. Pb-Bi oxide and Bi2O3were formed after the enrichment of Bi in the alloys due to the Pb depletion. The thickness of the oxide layer formed on liquid LBE at static condition was approximately 1mm. The oxidation rates of the alloys were much larger than that of the steels, and became larger with higher Pb concentration in the alloys. The compatibility of Pb-Bi alloys with stainless steel was worse when the Pb concentration in the alloys became low, since the dissolution type corrosion was promoted by the Bi composition in the alloy. The Pb-Li alloys were oxidized as they formed Li2PbO3and Li2CO3. Then, Li was depleted from the alloy. These oxides of the coolant can be generated in the low temperature region of the reactor system after the increase of oxygen concentration in the coolant system in the air ingress accident.