Abstract The investigation of the utilization of enriched 208Pb as a coolant to enhance the performance of a long-life fast reactor with a Modified CANDLE (Constant Axial shape of Neutron flux, nuclide densities, and power shape During Life of Energy production) burnup scheme has performed. The analyzes were performed on a reactor with thermal power of 800 MegaWatt Thermal (MWTh) with a refueling process every 15 years. Uranium Nitride (enriched 15N), 208Pb, and High-Cr martensitic steel HT-9 were employed as fuel, coolant, and cladding materials, respectively. One of the Pb-nat isotopes, 208Pb, has the smallest neutron capture cross-section (0.23 mb) among other liquid metal coolants. Furthermore, the neutron-producing cross-section (n, 2n) of 208Pb is larger than sodium (Na). On the other hand, the inelastic scattering energy threshold of 208Pb is the highest among Na, natPb, and Bi. The small inelastic scattering cross-section of 208Pb can harden the neutron energy spectrum. Therefore, 208Pb is a better neutron multiplier than any other liquid metal coolant. The excess neutrons cause more production than consumption of 239Pu. Hence, it can reduce the initial fuel loading of the reactor. The selective photoreaction process was developing to obtain enriched 208Pb. The neutronic was calculated using SRAC and JENDL 4.0 as a nuclear data library. We obtained that the modified CANDLE reactor with enriched 208Pb as coolant and reflector has the highest k-eff among all reactors. Meanwhile, the natPb cooled reactor has the lowest k-eff. Thus, the utilization of the enriched 208Pb as the coolant can reduce reactor initial fuel loading. Moreover, the enriched 208Pb-cooled reactor has the smallest power peaking factor among all reactors. Therefore, the enriched 208Pb can enhance the performance of a long-life Modified CANDLE fast reactor.

中文翻译：

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使用富集 208Pb 作为冷却剂提高长寿命改进型 CANDLE 快堆的性能

摘要 利用富集 208Pb 作为冷却剂来提高长寿命快堆性能的研究具有改进的 CANDLE（中子通量、核素密度和能量生产寿命期间的功率形状的恒定轴向形状）燃耗方案。执行。这些分析是在一个热功率为 800 兆瓦热 (MWTh) 的反应堆上进行的，每 15 年进行一次换料过程。氮化铀（富集 15N）、208Pb 和高铬马氏体钢 HT-9 分别用作燃料、冷却剂和包壳材料。其中一种 Pb-nat 同位素 208Pb 在其他液态金属冷却剂中具有最小的中子捕获截面 (0.23 mb)。此外，208Pb 的中子产生截面 (n, 2n) 大于钠 (Na)。另一方面，208Pb 的非弹性散射能量阈值在 Na、natPb 和 Bi 中最高。208Pb 的小非弹性散射截面可以硬化中子能谱。因此，208Pb 是比任何其他液态金属冷却剂更好的中子倍增器。过量的中子导致产生比消耗更多的 239Pu。因此，它可以减少反应堆的初始燃料负荷。选择性光反应过程正在发展以获得富集的 208Pb。使用 SRAC 和 JENDL 4.0 作为核数据库计算中子。我们发现，以富集 208Pb 作为冷却剂和反射器的改进型 CANDLE 反应器在所有反应器中具有最高的 k-eff。同时，natPb 冷却反应器的 k-eff 最低。因此，利用富集的 208Pb 作为冷却剂可以减少反应堆初始燃料负荷。而且，浓缩的 208Pb 冷却反应堆在所有反应堆中具有最小的功率峰值因子。因此，富集的 208Pb 可以提高长寿命改性 CANDLE 快堆的性能。