ナトリウム冷却高速炉の研究開発における熱分析の利用

摘要

資源の乏しい日本においては，エネルギーの安定供給は極めて重要な課題である。エネルギー安全保障の観点から，我が国では準国産エネルギーの長期的な確保を目的にウラン資源の有効利用(燃料の増殖)が可能な高速炉サイクル技術の開発が進められてきた。約4年ぶりに再稼動した九州電力の川内原子力発電所のような軽水炉(第3世代炉)とは異なり，高速炉(第4世代炉)は，核分裂を起こしにくいウラン238を高速中性子により核分裂を起こしやすいプルトニウム239に変換，増殖する原子炉であり，高速炉サイクルは，同炉で生じた使用済燃料のリサイクルを目指すものである。%This paper describes the application of thermal analysis in research and development of sodium-cooled fast reactor (SFR). In a SFR, the sodium-concrete reaction (SCR) should be considered when a hypothetical accidental condition such as the steel liner failure by leakage of liquid sodium (Na) was assumed. The major consequences of SCR are hydrogen release, energy release and concrete ablation. Thus, it is important to understand the with silica were studied using thermal analysis. Differential scanning calorimetry (DSC) equipped with a videoscope for in-situ observations of the reacting samples was successfully used for revealing the phenomenological features of the model reactions. Further, the kinetic features of the reactions were analyzed from DSC curves using the conventional kinetic calculation method, known as Kissinger method. Subsequently, the significance of the calculated kinetic parameters obtained for each model reaction was evaluated through the kinetic deconvolution analysis for the overlapping multi-step processes. The practical meanings of the kinetic parameters determined using the conventional kinetic analysis were discussed for utilizing these for the relative estimation of the reactivity and for the simulation of the overall behavior under real conditions.