Transuranic (TRU) elements can be used as an alluring fuel in a graphite-moderated Molten Salt Reactor (MSR) with liquid fuel and online reprocessing. However, the positive temperature feedback coefficient (TFC) stemming from the resolvable fission resonances of Pu-239 and Pu-241 at thermal neutron energies should be addressed. The aim of this study is to propose an effective solution to ameliorate the positive TFC, by adding Er-167 into the fuel salt or adjusting the minor actinides (MA) ratio in TRU. Er-167, with a strong capture resonance cross section of about 10,000 barns at 0.5 eV, is one of the most promising poisons. After adding Er-167 into the fuel salt with hectogram scale, the fuel TFC is decreased significantly to below −10 pcm/K and the total TFC to −2 pcm/K correspondingly. Similar to Er-167, some MA isotopes, especially Np-237 (at 0.5 eV) and Am-241 (at 0.3 eV, 0.6 eV and 1.1 eV) reveal significant capture resonance cross sections (>1000 barns). In this way, increasing the MA ratio in TRU is another available approach to obtain a negative TFC. The simulated results show that adjusting the MA ratio up to 50% can ameliorate the TFC efficiently. Combing the negative TFC and the salt solubility limit, only a narrow region of the fuel volume fraction lower than 25% can meet the two requirements, and the eligible region becomes smaller for a lower MA ratio.

超铀（TRU）元素可在带有液体燃料和在线后处理的石墨减速熔融盐反应堆（MSR）中用作诱人的燃料。然而，应解决由Pu-239和Pu-241在热中子能量下可分辨的裂变共振引起的正温度反馈系数（TFC）。这项研究的目的是通过向燃油盐中添加Er-​​167或调整TRU中的次act系元素（MA）比率，提出一种改善正TFC的有效解决方案。Er-167在0.5 eV时具有约10,000谷仓的强捕获共振截面，是最有前途的毒药之一。在以百克规模将Er-167添加到燃料盐中之后，燃料TFC显着降低至-10 pcm / K以下，总TFC则相应降低至-2 pcm / K。与Er-167类似，一些MA同位素 特别是Np-237（在0.5 eV时）和Am-241（在0.3 eV，0.6 eV和1.1 eV时）显示出明显的捕获共振截面（> 1000 barns）。这样，增加TRU中的MA比率是获得负TFC的另一种可用方法。仿真结果表明，将MA比例调节至50％可以有效改善TFC。结合负TFC和盐溶解度极限，只有燃料体积分数低于25％的狭窄区域才能满足这两个要求，并且对于较低的MA比，合格区域会变小。仿真结果表明，将MA比例调节至50％可以有效改善TFC。结合负TFC和盐溶解度极限，只有燃料体积分数低于25％的狭窄区域才能满足这两个要求，并且对于较低的MA比，合格区域会变小。仿真结果表明，将MA比例调节至50％可以有效改善TFC。结合负TFC和盐溶解度极限，只有燃料体积分数低于25％的狭窄区域才能满足这两个要求，并且对于较低的MA比，合格区域会变小。