Study on Ultra-Long Life Ores Lolled with Transuranium Fuels

由于被作为核废料处理的一些跨铀元素，如^&lt；237&gt；Np和^&lt；241&gt；Am具有较大的中子俘获截面，如果将它们装载到堆芯中，它们有很大的潜力降低初始过剩反应性，并建立高燃耗堆芯。对长寿命堆芯装载跨铀元素进行了可行性研究。结果表明，在轻水和重水反应堆中，装入^&lt；237&gt；NP的堆芯允许燃耗值达到150-200GWD/t。通过分析中子能谱对轻水、重水、氦气、二氧化碳气体、钠和蒸汽六种冷却剂堆芯长寿命堆芯特性和安全特性的影响，得出如下结论：装有~&lt；237&gt；NP的石墨慢化剂氦气冷却堆具有优良的堆芯特性。研究发现，装入~(241)Am的反应堆堆芯具有100GWD/t左右的高燃耗，同时也证实了装入~(237)Np和~(241)Am等铀元素的燃料具有良好的钚保护剂作用。研究了一种新的反应堆燃耗概念，即相对形状的中子通量、核素密度和功率密度是恒定的，但在反应堆运行的整个生命周期中以恒定的速度向轴向移动。在这一新概念中，提出了高燃耗约400GWD/t的超长寿命快堆。

As some of the trans-uranium elements such as ^<237>Np and ^<241>Am, which are treated as the nuclear wastes, have large neutron capture cross section, they have large potential to reduce the initial excess reactivity and also to establish the high burn-up reactor core if they are loaded in the core. The feasibility study on the long-life cores loaded with trans-uranium elements has been performed. It was found that the reactor core loaded with ^<237>Np allow the burn-up value up to 150-200 GWd/t in the light water and heavy water reactors. Based on the analysis of the neutron spectrum effects on the long-life core characteristics and safety characteristics of the reactor cores with six coolants such as light water, heavy water, He gas CO_2 gas, Na and steam, it was concluded that He gas cooled reactor with graphite moderator loaded with ^<237>Np gives excellent their characteristics. It was found that the reactor core loaded with ^<241>Am gives the high burn-up of about 100 GWd/t. It was also confirmed that those fuels loaded tans-uranium elements such as ^<237>Np and ^<241>Am produce ^<238>Pu, which is known as good protector of Plutonium against uncontrolled proliferation. A new reactor burn-up concept, where relative shapes neutron flux, nuclide densities and power density are constant but move to an axial direction with constant velocity during the whole life of the reactor operation, were also studied. It was proposed the very long-life fast reactor with high burn-up of about 400 GWd/t in this new concept.