压水堆核电站联氨减量化研究现状综述

Review on Hydrazine Reduction in Pressurized Water Reactor Nuclear Power Plant

国外针对联氨减量化技术开展了大量研究工作,并取得了良好的应用效果,但是国内相关研究工作还处于起步阶段,本文针对联氨处理、联氨减量和联氨替代三个部分开展了调研工作。联氨处理技术主要使用空气鼓泡处理和过氧化氢处理两种工艺,可在72h内将联氨浓度降到1mg/kg以下。联氨减量技术需要考虑多项因素的影响,包括易受影响的内部组件的实际腐蚀裕度,湿保养的持续时间,污泥中铜的质量,保养溶液的pH值,是否应用氮气覆盖层,保养液中的溶解氧浓度和材料的钝化程度等。联氨替代技术主要选择毒性低于联氨的二回路除氧剂,包括碳酰肼、二乙基羟胺和异丙基羟胺等。其中,碳酰肼应用较为成功,但是仍需考虑低pH的潜在影响,以及碳酰肼对SG排污水中铁含量的影响。

Foreign countries have carried out a lot of research work on hydrazine reduction technology,and achieved good application effects, but domestic related research work is still in the initial stage, this paper carried out research work on hydrazine treatment, hydrazine reduction and hydrazine substitution.Hydrazine treatment technology mainly uses air bubbling treatment and hydrogen peroxide treatment two processes, which can reduce the hydrazine concentration to less than 1mg/kg within 72 hours. Hydrazine reduction technology requires consideration of several factors, including the actual corrosion margin of vulnerable internal components, duration of wet maintenance, quality of copper in sludge, pH value of maintenance solution, application of nitrogen coating, concentration of dissolved oxygen in maintenance solution and passivation degree of the material. Hydrazine substitution technology mainly selects the two-circuit deoxidizer whose toxicity is lower than hydrazine, including carbonyl hydrazine, diethyl hydroxylamine and isopropyl hydroxylamine. Among them, carbonyl hydrazine has been successfully applied, but the potential influence of low pH and the influence of carbonyl hydrazine on the iron content in SG effluent still need to be considered.