CONPREHENSIVE STUDY ON THORIUM AS AN ENERGY SOURCE IN 21 CENTURY

1.钍燃料反应堆的设计研究：(1)核数据：测量了钍的瞬发裂变中子谱和双微分中子散射截面。对钍与U-233的共振干扰进行了实验研究。我们评估了U-232的核数据，结果被纳入JENDL-3。(2)反应堆设计：对富士小型熔盐反应堆进行了概念设计。研究了以U-233为燃料的压水堆堆芯和本质安全型高通量反应堆的特性。比较了钍燃料反应堆和铀燃料反应堆中放线的产率。(3)Kuca堆上载钍堆芯的Keff值与实验值和理论值之间有很好的一致性。(4)对含钍的氢化物进行了初步实验。(5)探讨了钍循环在准平衡核社会中的意义。以钍为燃料的反应堆燃料及其他材料：(1)碳化钍的非化学计量研究。(2)研究了碲对不锈钢的腐蚀行为。(3)氧在(Th，U)O_2中的化学扩散与晶格常数无关。(4)对冷冻法制备(U，Th)O_2粉末进行了实验研究。(5)观测了经辐照的钍的伽马射线能谱和同位素比值。(6)在2300ﾟ℃下测量了辐照包覆燃料的FP释放量。(7)研究了熔融燃料和熔融燃料反应堆结构材料的特性。(8)溶解物质(CaCO_3 AQ.)都是通过实验获得的。

1. Design Study of Thorium Fuelled Reactors : (1) Nuclear data : The prompt fission neutron spectrum and the double differential neutron scattering cross section for thorium were measured. Experimental study on resonance interference between thorium and U-233 was attempted. We evaluated the nuclear data for U-232 and the result was incorporated in JENDL-3. (2) Reactor design : Conceptual design of a small molten salt reactor named FUJI was carried out. The characteristics of a HCPWR core and an inherent safe high flux reactor both with U-233 fuel were investigated. Production rate of actinidesin thorium fuelled reactors was compared with those in Uranium ones. (3) Excellent agreement was seen between the experimental and theoretical Keff values for thorium loaded cores at KUCA. (4) Preliminary experiment for a hydrid with thorium was carried out. (5) Significance of the thorium cycle in a quasi-equilibrium nuclear society was investigated.2. Fuel and Other Materials for Thorium Fuelled Reactors : (1) Non-stoichiometric study for thorium carbide was done. (2) We observed corrosion behavior of stainless steel by tellurium. (3) Chemical diffusion of oxygen in (Th, U)O_2 was investigated to show no dependence on lattice constants. (4) Production of (U, Th)O_2 powder by freezing method was experimentally studied. (5) We observed gamma ray spectra and isotopic ratios for irradiated thorium. (6) FP release from irradiated coated partic fuel was measured at 2300ﾟC. (7) We investigated the characteristics of molten fuel and structural materials for molten fuelled reactors. (8) Deposition phenomena of dissolved materials (CaCO_3 aq.) were experimentally obtained.