Molybdenum is a potential material for future nuclear fusion experiments and power plants. It has good thermo-mechanical properties and can be readily fabricated, making it attractive as an alternative material to tungsten (the current leading candidate) for high neutron flux and high thermal load regions of fusion devices. Unfortunately, exposure to those fusion neutrons is predicted to cause significant long-term radioactivity in elemental Mo, which would be a problem during maintenance and decommissioning operations. Simulation predictions indicate that Mo activation could be reduced by isotopic adjustment (biasing). If these predictions are proven, then Mo could be used in future demonstration and commercial reactors without significantly increasing the amount of long-term, higher-level radioactive waste. Transmutation (inventory) simulations used to predict activation rely on nuclear reaction data. The quality of these data impact on the confidence and uncertainty associated with predictions. Recently, UKAEA has developed benchmarks to test and validate the FISPACT-II inventory code and the input nuclear data libraries. Verification of molybdenum inventory simulations is performed against experimental decay-heat measurements from JAEA’s fusion neutron source (FNS) facility and using new data acquired from γ-spectroscopy measurements of Mo irradiated in the ASP 14 MeV facility in the UK. Results demonstrate that FISPACT-II predictions (with TENDL libraries) for Mo are accurate for activity generated from the shorter-lived radionuclides explored by these laboratory experiments. However, these kinds of experiments are limited in their coverage of the important radionuclides and decay timescales, and thus further experiments with fusion relevant operational scenarios and alternative measurement techniques are still needed.

中文翻译：

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钼及其同位素在聚变应用中库存模拟的实验验证

钼是未来核聚变实验和发电厂的潜在材料。它具有良好的热机械性能并且易于制造，使其作为钨（目前的主要候选材料）的替代材料具有吸引力，可用于聚变装置的高中子通量和高热负荷区域。不幸的是，预计暴露于这些聚变中子会导致元素 Mo 产生显着的长期放射性，这在维护和退役操作期间将是一个问题。模拟预测表明可以通过同位素调整（偏置）减少 Mo 活化。如果这些预测得到证实，那么 Mo 可以用于未来的示范和商业反应堆，而不会显着增加长期高放射性废物的数量。用于预测活化的嬗变（库存）模拟依赖于核反应数据。这些数据的质量会影响与预测相关的置信度和不确定性。最近，UKAEA 开发了用于测试和验证 FISPACT-II 清单代码和输入核数据库的基准。钼库存模拟的验证是针对来自 JAEA 的聚变中子源 (FNS) 设施的实验衰变热测量值进行的，并使用从英国 ASP 14 MeV 设施中辐照的钼的 γ 光谱测量获得的新数据。结果表明，FISPACT-II 对 Mo 的预测（使用 TENDL 库）对于这些实验室实验探索的寿命较短的放射性核素产生的活性是准确的。然而，