Study on Fundamental Processes of Formation, Conversion and Dissolution of Crud in Nuclear Reactor Environments.

1)模拟CRUD的形成与表征：采用五种不同的方法制备了不同组成的磁铁矿，考察了不同铁氧化物和氢氧化物与Ni(OH)_2和Co(OH)_2的反应活性。α-FeOOH与Ni(OH)_2和Co(OH)_2的反应活性极高，在150-300ﾟC时生成NiFe_2O_4和CoFe_2O_4。α-FeOOH和α-Fe_2O_3与Ni(OH)_2的反应活性较低，而细小的α-FeOOH和α-Fe_2O_3与Ni(OH)_2反应。考察了联氨、EDTA浓度、温度等因素对磁铁矿溶解速率的影响，并对溶解机理进行了初步探讨。在含有13EA-Hout肼的溶液中，磁铁矿在pH 5~10范围内的溶解速度服从抛物线规律。在pH为4时，溶出分两个阶段进行，第一阶段遵循抛物线速率L…在含肼的溶液中，溶解分两个阶段进行，第一阶段在浓度为0.001-0.003 moldm~(-3)时服从抛物线速率定律，第二阶段在浓度为0.005~0.010 moldm~(-3)~(-3)时服从线性速率规律，第二阶段在浓度为0.005~0.010 moldm~(-3)~(-3)时服从时间指数为2的速率定律；.3)建立与化学去污有关的数据库：尝试建立与冷却剂的化学去污有关的CRUD的形成、转化、溶解和去污的数据库13：水冷核反应堆电路。此外，还论证了各种铁氧化物的形成和转化以及尖晶石化合物的形成与CRUD形成有关的研究结果。研究还包括CRUD行为的模拟、CRUD的激活和反应堆冷却剂回路的净化。较少

1) Formation and characterization of simulated crud : Magnetite with different composition was prepared by five different methods, and reactivities of various iron oxides and hydroxides with Ni(OH)_2 and Co(OH)_2 were investigated. The reactivity of gamma-FeOOH with Ni(OH)_2 and Co(OH)_2 was extremely high, and gamma-FeOOH formed NiFe_2O_4 and CoFe_2O_4 at 150-300ﾟC.The reactivities of alpha-FeOOH and alpha-Fe_2O_3 with Ni(OH)_2 were low, but fine alpha-FeOOH and alpha-Fe_2O_3 were reactive towards Ni(OH)_2. Fe_3O_4 did not react with either Ni(OH)_2 or Co(OH)_2.2) Dissolution mechanism of magnetite : Conditions of solutions (pH, concentrations of hydrazine and EDTA, and temperature) against dissolution rates of magnetite were investigated and the mechanism of dissolution was estimated. In the solutions wit13EA\ : hout hydrazine, dissolution rates of magnetite obeyed to parabolic rate law in pH 5-10. At pH 4, dissolution proceeded in two stages ; the first stage obeyed paraboric rate l … More aw, and the second the rate law with time exponent of 2. In the solutions c13EA\ : ntaining hydrazine, dissolution proceeded in two stages ; the first stage obeyed the parabolic rate law, and the second stage linear rate law at concentrations of 0.001-0.003 mol dm^<-3>, and the first stage obeyed linear rate law, and the second sta13EA\ : ge the rate law with time exponent of 2 at the concentrations of 0.005-0.010 mol dm^<-3>.3) Construction of data base in connection with chemical decontamination : The construction of a data base of the formation, conversion, dissolution and decontamination of crud was attempted in connection with the chemical decontamination of coolant13EA\ : circuits of water-cooled nuclear rreactors. In addition, the results of searches about the formation and conversion of various iron oxides, and the formation of spinel compounds were demonstrated in connection with crud formation. The searches were13EA\ : also carried out on the modelling of crud behaviors, the activation of crud and the decontamination of coolant circuits of reactors. Less