Abstract

Lattice physics and core physics studies have been carried out to investigate the reactor physics feasibility of destroying americium (Am) and curium (Cm) using special target fuel bundles in blanket fuel channels in a heterogeneous seed-blanket pressure tube heavy water reactor (PT-HWR) core fueled primarily with natural uranium. Results indicate that it should be feasible to achieve net-zero production of Am in a single PT-HWR core using 10 to 16 dedicated blanket channels containing Am-based target bundles while only one dedicated blanket channel would be required for achieving net-zero production of Cm. While the use of target blanket fuel bundles with fuel elements made of Am or Cm mixed with thorium (Th) in oxide form ((Am,Th)O₂, (Cm,Th)O₂) is expected to be suitable for transmutation purposes, the use of fuel elements made of pure americium oxide, especially those in the form of AmO_1.55, may not be suitable for transmutation purposes because of potential issues with fuel melting under high-power operations or postulated accident scenarios. The potential to achieve net-zero production of Am and Cm in a single thermal-spectrum reactor, such as a PT-HWR, could help eliminate the need to build and qualify a deep geological repository (DGR) capable of storing minor actinides for a long time (>1 million years). At the very least, the size and/or number of DGRs required for storing radioactive waste could be reduced significantly. Thus, destroying Am and Cm in PT-HWRs could be regarded as a viable solution to the perceived problem of nuclear waste and may help improve public acceptance of the use of nuclear energy. In addition, it may be possible to apply a similar approach for destroying MAs in other Generation III+ (Gen-III+)/Generation IV (Gen-IV)/small modular reactor (SMR) technologies.

摘要

已经进行了晶格物理和堆芯物理研究，以研究在多相种子包覆压力管重水反应堆 (PT- HWR）核心主要以天然铀为燃料。结果表明，使用 10 到 16 个包含基于 Am 的目标束的专用覆盖通道在单个 PT-HWR 核心中实现 Am 的净零生产应该是可行的，而实现净零生产只需要一个专用的覆盖通道厘米。而使用由 Am 或 Cm 与氧化物形式的钍 (Th) ((Am,Th)O ₂ , (Cm,Th)O ₂) 预计适用于嬗变目的，使用由纯氧化镅制成的燃料元件，尤其是那些以 AmO _1.55形式的燃料元件，可能不适合嬗变目的，因为在高功率运行或假设的事故情景下燃料熔化的潜在问题。在单个热谱反应堆（如 PT-HWR）中实现 Am 和 Cm 的净零产量的潜力有助于消除建造和鉴定能够储存次要锕系元素的深层地质储存库 (DGR) 的需要，很长时间（> 100 万年）。至少，可以显着减少储存放射性废物所需的 DGR 的大小和/或数量。因此，销毁 PT-HWR 中的 Am 和 Cm 可被视为解决核废料问题的可行解决方案，并可能有助于提高公众对核能使用的接受度。此外，