【作者】 尹陈艳；

【导师】 龚学余；

【作者基本信息】 南华大学 ， 核技术及应用， 2010， 硕士

【摘要】 加速器驱动放射性洁净核能系统(ADS),由于其良好的资源效益、环境效益和安全效益而成为新一代核能源的可能选择,近年来在国际上形成一个研究热点。散裂靶是该系统的一个关键而技术难度极大的重要部件。ADS在嬗变核废料的同时,高能、大流强质子与靶的散裂反应又不断产生放射性散裂产物。为此,有必要对散裂靶的辐射防护问题进行研究,以评价其对环境的辐射危害。本论文采用MC(Monte Carlo)方法对ADS中散裂靶受质子照射一段时间后积累的较长寿命散裂产物的量,以及靶从次临界系统中取出后放入水体中对环境产生的辐射危害进行了研究。研究结果表明:不同能量质子照射靶一段时间后,各靶在水体中产生的辐射剂量主要分布在沿靶径向的10～30cm和距靶两底面的15cm范围内,且剂量大小随着入射质子能量的增大而增大;在相同能量质子照射各靶一段时间后,钨靶产生的辐射剂量最小,铅-铋靶和铀靶产生的辐射剂量比钨靶高了6个数量级,且在中能质子照射后,铅-铋靶与铀靶的辐射剂量率相差不大,随着入射质子能量升高,铅-铋靶的辐射剂量增大得比铀靶快;散裂靶水体封装后,各靶产生的辐射剂量随存放时间衰减得很快,10年后趋于基本稳定,且剂量率较小,最终铅-铋靶的剩余辐射剂量相对要大,钨靶最小。更多还原

【Abstract】 Accelerator Driven Sub-critical System (ADS) becomes a new option of nuclear energy, due to its good cost efficiency, environmental benefits and security benefits. It becomes a research hotspot in recent years in the international arena. Spallation target is a crucial and important component with great technical difficulty in this system. When nuclear wastes are transmuted in ADS, radioactive spallation products are produced constantly following spallation reactions of High energy and high-flux protons with the target. Therefore, it is necessary to study the problem of spallation target to evaluate the radiation hazards on the environment.In this paper, the nuclear number of long-life spallation products irradiated by protons for period of time,and the radiation hazards to the environment after the targets be taked out from ADS are researched. The results are as follows.Irradiated by protons for a period of time, the radiation doses of spallation targets are mainly distributed along the radial target of 10-30cm and 15cm away from the underside of target. And a dose-dependent with the increase of proton energy increases. Irradiated by the same energy proton, the dose of tungsten target is minimum, but the dose of lead-bismuth target and uranium target are six orders of magnitude. The dose of lead-bismuth target is similar to uranium target, but increases faster with the incident proton energy increasing. After packaged by water, the radiation dose of targets are decayed rapidly. It will be to basically stable 10 years later. Finally, the remaining radiation dose of lead-bismuth target is relatively large, tungsten target’s is minimum.更多还原