Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV, SRTE/LRTA, SEREN/LEREN, SAME/LMRE, BP 3, 13115 Saint-Paul-lez-Durance, France.
Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV, SRTE/LRTA, SEREN/LEREN, SAME/LMRE, BP 3, 13115 Saint-Paul-lez-Durance, France.
Sci Total Environ. 2020 Jun 25;723:137873. doi: 10.1016/j.scitotenv.2020.137873. Epub 2020 Mar 14.
The Rhone River is one of the most nuclearized river in the world. Radionuclide concentrations in water and suspended sediments transferred to the marine environment were intensively monitored in this river over the last decades (2002-2018). Over this period of time, >12 and 25 time integrating samples were collected each year in filtered waters and suspended sediments, respectively, and analyzed for their radionuclide contents at ultra-trace levels by using top performance analytical tools. While >60% of plutonium, americium, cesium, cobalt, silver, beryllium and actinium radioisotopes are carried by sedimentary particles, sodium, tritium, antimony and strontium are mainly exported as dissolved species (>90%) due to their low affinity with particles. Most natural radionuclides contents show low seasonal variation. No significant trends are observed over the last two decades for these elements, even for K widely used in fertilizers after the middle of the last century, indicating that the basin has currently converged towards geochemical equilibrium for all of them. In contrast, the concentrations of numerous anthropogenic radionuclides originating from nuclear industries significantly declined since the beginning of the 2000s. Assuming no change of the current anthropic and climatic pressures over the next decades, apparent periods, i.e. the time required for a reduction by half the concentrations in the downstream part of the Rhône River, would be close to 6 years for most artificial radionuclides, except for tritium and other artificial radionuclides conveyed to the river by soil leaching and erosion (Sr, Am, plutonium isotopes) which would be far longer. Referring to regional referential backgrounds, only few anthropogenic radionuclides specifically produced by nuclear industries are still detectable at the downstream part of the Rhone River and excess contents of tritium, Pu and Am are observed in filtered waters.
罗纳河是世界上核污染最严重的河流之一。在过去的几十年里（2002-2018 年），对该河流中的水中和悬浮沉积物中的放射性核素浓度进行了密集监测。在此期间，每年分别在过滤水和悬浮沉积物中采集了>12 次和 25 次时间积分样本，并使用最先进的分析工具在痕量水平上分析其放射性核素含量。虽然>60%的钚、镅、铯、钴、银、铍和锕放射性同位素由沉积物颗粒携带，但由于与颗粒的亲和力低，钠、氚、锑和锶主要以溶解态（>90%）输出。大多数天然放射性核素含量的季节性变化较小。在过去的二十年中，这些元素没有观察到明显的趋势，即使是上个世纪中叶广泛用于肥料的钾也是如此，这表明该流域目前已经达到了所有元素的地球化学平衡。相比之下，自 21 世纪初以来，来自核工业的许多人为放射性核素的浓度显著下降。假设未来几十年内当前的人为和气候压力没有变化，那么在罗纳河下游，浓度减半所需的明显时间段（即）将接近 6 年，除了氚和其他通过土壤淋溶和侵蚀（Sr、Am、Pu 同位素）带入河流的人工放射性核素外，这些核素的时间将长得多。参考区域参考背景，只有少数特定由核工业产生的人为放射性核素仍可在罗纳河下游检测到，并且在过滤水中观察到氚、Pu 和 Am 的含量过高。
