Report of the Bulk Working Group

[摘要] The world in general and the USA in particular are facing an oncoming energy shortage. One key mechanism to provide carbon-free energy is nuclear fission. At this point, 20% of the US electrical power grid is supplied by nuclear energy. (Interestingly, it is 50% in Illinois.) European nations such as Sweden (50% nuclear electricity) and France (80% nuclear electricity) are pushing ahead with permanent radioactive waste storage and processing. If nothing else, the USA needs to provide the scientific foundation for improving its nuclear-power generation facilities. One key issue and how the APS could affect it are discussed below. (This discussion of this issue is not meant to be a comprehension argument in support of a facility but merely an example of the sort of science that could be pursued. An exhaustive collection of arguments would take more time and effort.) The modification of various zones inside a nuclear fuel is an important issue. This includes microscopic re-crystallization, stress, fission gas production, He bubble formation and the intermixing, depletion and enrichment of various chemical, daughter and other isotopic species. For example, past studies of the ternary nuclear fuel UPuZr have demonstrated constituent redistribution when irradiated or with thermal treatment. The concentration variations shown above are of significant concern. Driven in part by the thermal gradient within the nuclear fuel, these variations can affect reactor performance and fuel burn-up levels. Similar gradients were observed in samples that were not irradiated but underwent thermal gradient treatments. From measurement such as these, kinetic parameters such as effective inter-diffusion coefficients were derived. The amount of such experimental data is very limited. Interaction of the fuel constituents with cladding and coolant are also important. At present, INL scientists pursue a number of measurements on-site at INL and off-site to address issues such as this. Here, we will propose two key examples of how a new facility at the APS could impact this technological issue.

[发布日期] 2010-02-09

[学科分类] 材料科学（综合）

[关键词] BUBBLES;COOLANTS;ELECTRICITY;ENERGY SHORTAGES;FISSION;KINETICS;MODIFICATIONS;NUCLEAR ENERGY;NUCLEAR FUELS;NUCLEAR POWER;PERFORMANCE;PROCESSING;PRODUCTION;RADIOACTIVE WASTE STORAGE;SWEDEN;TEMPERATURE GRADIENTS