Study on New Water Chemistry Control for Stabilization of Oxide Films in Coolant Systems of Light Water Reactors

日本LWR中水化学的现状被广泛地审查了与相关专家的文献和讨论。然后锌注射和高贵的金属化学添加剂被挑选为这个项目中的主要项目。从实验上和分析上看，锌注射的形式的复合磁铁和铬是一种与Fe和铬的相互作用的结果，尊重，在不锈钢和燃料层的表面上，以及内部氧化物层中的钴累积（Chromites）在不锈钢表面上的不锈钢具有抑制作用，而当锌注射时，它不一定具有抑制钴拾取物在外层的抑制作用（ferrites）.研究结果显示，锌注射形式非常薄的锌铬内氧化物层，这是一种非常稳定的热力学方法，并且可以明显减少不锈钢的腐蚀，间接地对减少钴累积产生影响，这也是一个展示的实验。 ... More y，其中Cr（VI）离子在aquous phase oxidizes Zr上接触，并且在其表面上被预测为amorphous Cr（III）氧化物在锌离子的缺失中，但作为crystaline锌铬在锌离子存在。这种铬沉积物被认为与燃料表面沉积物中的钴分解密切相关，并被发现可以通过Zircaloy的前条件下被明显抑制。铂注射现在被期望使氢注射在BWR中更有效，和Pt（II）的四氨复合物和Pt（IV）的六氢氧化物复合物的化学行为已被调查为伽马下的一类解决方案辐射：Pt（II）复合体在加热到120 - 150 ℃的过程中很容易减少和形成Pt金属，而Pt（IV）复合体没有减少，而且通常只在加热时形成Pt金属。Gamma irradiation readily reduces both of the Pt complexes to Pt metal in the presence of H-D22-D2 or alcohols， but not in the presence of O-D22-D2。“The Diameters and the Catalytic Property of Pt金属形成的小粒子，由于粒子制备条件的影响，被发现受到了较大影响。”这一结果显示，辐射的影响在真实植物中非常重要，特别是在高贵的金属添加剂中。Less（低）

The present status of water chemistry in Japanese LWR was widely reviewed from literature and discussion with relevant experts. Then zinc injection and noble metal chemical addition were picked up as major subjects in this project.It was shown experimentally and analytically that zinc ion injected forms complex ferrites and chromites as a result of interaction with Fe and Cr ions, respectively, on the surfaces of stainless steel and fuel cladding and that cobalt accumulation in the inner oxide layer (chromites) on the surface of stainless steel is suppressed effectively by zinc injection while it is not necessarily effective for the suppression of cobalt pick-up in the outer layer (ferrites).The experimental result showed that zinc injection forms very thin inner oxide layer of zinc chromite that is very stable thermodynamically and thus reduces remarkably the corrosion of stainless steel, consequently being effective for reducing the cobalt accumulation.It was also shown experimentall … More y that Cr(VI) ion in aqueous phase oxidizes Zr on contacting with Zircaloy and is precipitated on its surface as amorphous Cr(III) oxides in the absence of zinc ion but as crystaline zinc chromite in the presenee of zinc ion. This Cr deposition is considered to be closely related with cobalt dissolution from the surface deposits of the fuel and was found to be remarkably suppressed by the pre-conditioning of the Zircaloy.Platinum injection is now expected to make hydrogen injection more effective in BWR, and the chemical behavior of a tetra-ammine complex of Pt(II) and hexa-hydroxo-complex of Pt(IV) was investigated in aqueous solutions under gamma-irradiation.The Pt(II) complex is easily reduced and forms Pt metal in aqueous phase by heating to 120 〜 150 ℃ while the Pt(IV) complex is not reduced and consequently does not form Pt metal only by the heating. Gamma irradiation readily reduces both of the Pt complexes to Pt metal in the presence of HィイD22ィエD2 or alcohols, but not in the presence of OィイD22ィエD2. The diameters and the catalytic property of the small particles of Pt metal formed were found to be largely affected by the condition of the particle preparation. This result shows that the effect of radiation is very important in the noble metal addition in real plants. Less