Abstract

In the framework of sodium fast reactors, the management of tritium contamination in the sodium secondary circuit and the control of its release into the atmosphere is fundamental. In order to capture and recover tritium by coprecipitation worth hydrogen in cold traps, it is necessary to maintain a certain amount of hydrogen dissolved in the liquid sodium stream. Hydrogen injection by permeation through nickel membranes has been proposed to provide a continuous hydrogen intake to a liquid sodium stream, allowing the desired hydrogen concentration to be reached. A permeator prototype and the related process have been designed. Permeation tests have been carried out in an experimental facility set up at CEA Cadarache at sodium temperatures from 375°C to 450°C and hydrogen partial pressures from 5 × 10³ to 3 × 10⁴ Pa in order to quantify their influence on hydrogen permeation flux. Measurements on both the gas and sodium sides provide a complete hydrogen content observability over the system. Experimental results show a good agreement with the theoretical permeation laws for hydrogen pressures below 2 × 10⁴ Pa and provide an estimation of the temperature dependency of the permeability coefficient, which will be useful for the industrial scale-up of the process.

摘要

在钠快堆的框架内，钠二回路中氚污染的管理及其向大气中释放的控制至关重要。为了在冷阱中通过共沉淀有价值的氢气来捕获和回收氚，需要保持一定量的氢气溶解在液态钠流中。已经提出通过镍膜渗透注入氢气，以向液态钠流提供连续的氢气摄入，从而达到所需的氢气浓度。已经设计了渗透器原型和相关工艺。渗透测试已在 CEA Cadarache 的实验设施中进行，钠温从 375°C 到 450°C，氢分压从 5 × 10 ³到 3 × 10⁴  Pa 以量化它们对氢渗透通量的影响。气体侧和钠侧的测量提供了对系统的完整氢含量可观察性。实验结果表明氢气压力低于 2 × 10 ⁴  Pa 时与理论渗透定律有很好的一致性，并提供了对渗透系数的温度依赖性的估计，这将有助于工艺的工业放大。