Abstract Radioisotopes represent major sources of ionizing radiation, not least for use in medical applications, brachytherapy and nuclear medicine included. In this, the nuclear reactor is the main source of β- - γ emitting isotopes, an example product being 153Sm used in the treatment of pain arising from bone metastases. Present analysis relates to the potential of gadolinium neutron capture reaction, its impact on reactor production of radioisotopes and the proliferation resistant potential of thorium fuel cycle. A comparative analysis has been made of the impact of gadolinium on the production of 153Sm by UO2 and (Th, U) O2 fuels in a Westinghouse small modular reactor. Five fuel assemblies were investigated: one containing no gadolinium, the other four containing 16, 24, 34 or 44 gadolinium fuel rods. The code Monte Carlo N-Particle eXtended (MCNPX) integrated with the CINDER90 burn-up code was used for calculations. In the production of 153Sm the same trend is followed for the fuels containing gadolinium, increasing significantly with the number of gadolinium fuel rods. Zero production results from fuel assemblies without gadolinium. The concentration of 153Sm increases significantly with burn-up, indicating that gadolinium has a positive impact on the production of 153Sm.

中文翻译：

---

钆对153Sm反应堆产量的影响

摘要 放射性同位素是电离辐射的主要来源，尤其适用于医疗应用，包括近距离放射治疗和核医学。在这方面，核反应堆是 β- - γ 发射同位素的主要来源，一个示例产品是 153Sm，用于治疗骨转移引起的疼痛。目前的分析涉及钆中子俘获反应的潜力、其对反应堆放射性同位素生产的影响以及钍燃料循环的抗扩散潜力。已经对钆对西屋小型模块化反应堆中 UO2 和（Th，U）O2 燃料生产 153Sm 的影响进行了比较分析。研究了五种燃料组件：一种不含钆，另四种含有 16、24、34 或 44 钆燃料棒。与 CINDER90 燃尽代码集成的代码 Monte Carlo N-Particle eXtended (MCNPX) 用于计算。在 153Sm 的生产中，含钆燃料也遵循同样的趋势，随着钆燃料棒数量的增加而显着增加。不含钆的燃料组件可实现零产量。153Sm 的浓度随燃耗显着增加，表明钆对 153Sm 的产生有积极影响。