A new methodological approach is proposed to calculate activation levels of flowing liquids under irradiation by coupling CFD analyses with activation physics. It overcomes the limitations of the conventional one, which assumes a simple linear dependency of residence times with flowrate that is only valid in a limited number of fluid-dynamic regimes. The new approach is more generally applicable and, as a consequence, successful in improving the post-analysis of a recent ITER water activation experiment. C/E values which with the conventional approach were very different from unity and showed a clear pattern with flowrate are now close to unity and showing a flat profile. Results are encouraging and suggest that the new approach leads to improved predictive capability for more complex applications in ITER and beyond. It is demonstrated that, under the particular conditions of the above experiment, the conventional approach always leads to under-prediction of activation levels downstream compared to the new one for the case of decay only, whereas it always leads to over-prediction for the case of irradiation and decay. The magnitude of the under- or over-predictions depends intricately on the actual flow patterns, flowrate and nuclide half-life.

提出了一种新的方法学方法，通过将CFD分析与活化物理耦合，来计算辐射下流动液体的活化水平。它克服了传统方法的局限性，后者假设停留时间与流速之间存在简单的线性相关性，而这种依赖关系仅在有限数量的流体动力学状态下才有效。新方法更普遍适用，因此，成功地改善了最新ITER水活化实验的后分析。Ç / ë传统方法的值与单位值非常不同，并且显示出清晰的流量图形，现在接近单位值并显示出平坦的轮廓。结果令人鼓舞，并表明新方法可提高对ITER及以后的更复杂应用的预测能力。结果表明，在上述实验的特定条件下，常规方法总是导致下游激活水平的预测不足，而仅在衰减情况下才与新方法相比，而总是导致对这种情况的过度预测。辐射和衰变。预测不足或预测过度的大小取决于实际的流量模式，流量和核素半衰期。