行波快堆中的临界波特性研究

Fast reactor technology is a key step towards the sustainable utilization of nulear power. Current research will focus on the critical wave in the traveling wave fast reactor. After a nuclear critical wave is triggered in the ignitor zone of the core, the wave will move in a designated direction through the subcritical zone. However, there is no a well-accepted critical wave theory. This research will establish the general critical wave governing equations based on theoritical work, and by appling the solitary wave theory, a solitary wave solution to the equations will be constructed, then the generation, development and annihilation of the critical wave will be studied. A modified Monte Carlo code will be used to benchmark the prediction of critical wave equations and solitary solution, and optimize the wave characteristics in traveling wave reactors under the guide of the theoritical analysis.

发展快堆技术是实现核能可持续利用的关键一环。本研究对象为行波快堆中的核临界波，堆芯点火区'点火'产生核临界波后，该波将在次临界区定向移动，临界波所处区域的中子通量分布，核素密度分布以及功率分布都是不变的。目前尚未形成一个广泛认可的临界波分析理论。本项目将从理论研究入手，建立较通用的临界波控制方程，应用孤立波理论，构造求解该方程的临界波解，研究临界波的产生、发展以及湮灭的机理；然后应用改进的蒙特卡洛程序对该方程和孤立波解进行验证计算，并在理论解的指导下计算优化行波快堆中临界波的传播性能。

行波快堆使用天然铀或者热堆乏燃料作堆芯次临界区燃料，通过堆芯点火区‘点火’产生核临界后，该临界波将在次临界区定向移动，理想状态下，临界波所在区域的中子通量分布，核素密度分布以及功率分布都是不变的。本研究首先对临界波的稳定性条件进行了梳理，然后基于现有确定论程序，以钠冷快堆为基础，进行了堆型设计和三维初步分析，通过实际计算结果对临界波在堆内的传递波速等作出研究说明。通过计算，波速在5-7cm/a，未见波形偏置等情况出现，临界波传递稳定。