AP1000一回路氧化膜特性研究

AP1000与一般压水堆不同的是其一回路采用注锌加氢技术,使其一回路氧化膜特性发生变化。试验在高压釜中模拟AP1000一回路水化学工况,研究F304L、F316、690三种反应堆主工艺设备材料表面生成的氧化膜特性。结果表明,氧化膜为双层结构,外层氧化膜成分主要是Fe₂O₃及Fe₃O₄。F304L不锈钢与F316不锈钢内层氧化膜主要是ZnCr₂O₄,注入的Zn元素取代了FeCr₂O₄中的铁元素,形成了致密的ZnCr₂O₄ 氧化层,内层氧化膜存在少量ZnO和ZnFe₂O₄。690合金的氧化膜内层为ZnCr₂O₄,同时存在较高含量的ZnO和ZnFe₂O₄。与前两者不同的是,690合金的氧化膜含少量的二价镍,以NiFe₂O₄和NiCr₂O₄形式存在。加锌加氢使得氧化膜更加致密,也明显变薄。

Research of oxide film properties of AP1000 primary loop

The difference between AP1000 and other general PWRs is that its primary loop adopts zinc in-jection and hydrogenation technology, which changes the characteristics of oxide film in the pri-mary loop. The experiment simulates water chemistry condition of AP1000 primary loop in auto-clave to study the characteristics of the oxide film formed on the surface of the three main reactor process equipment materials of F304L, F316, and 690. The results show that the oxide film is a bilayer structure, and the outer oxide film components are mainly Fe₂O₃ and Fe₃O₄. The inner oxide film of F304L and F316 stainless steel is mainly ZnCr₂O₄, and the injected Zn element replaces the iron element in FeCr₂O₄ to form a dense ZnCr₂O₄ oxide layer. A small amount of ZnO and ZnFe₂O₄ is present in the inner oxide film. The inner oxide film of 690 alloy is ZnCr₂O₄, with high content of ZnO and ZnFe₂O₄. Unlike F304L, F316, the oxide film of the 690 alloy contains a small amount of divalent nickel in the form of NiFe₂O₄ and NiCr₂O₄. The addition of zinc and hydrogen makes the oxide film denser and sig-nificantly thinner.