Laboratoire de Radioécologie de Cherbourg-Octeville, Institut de Radioprotection et de Sûreté Nucléaire/PSE-ENV/SRTE, Rue Max Pol Fouchet, BP10, 50130, Cherbourg-en-Cotentin, France.
Laboratoire de Mesure de la Radioactivité dans l'Environnement, Institut de Radioprotection et de Sûreté Nucléaire/PSE-ENV/SAME, Bât. 501, Bois des Rames, Rue du Belvédère, 91400, Orsay, France.
J Environ Radioact. 2020 Nov;223-224:106381. doi: 10.1016/j.jenvrad.2020.106381. Epub 2020 Sep 8.
The Channel Islands are located in the Normand-Breton Gulf (NBG), in the mid-part of the English Channel (France, Normandy). In the northern part, off Cap La Hague, controlled amounts of radioactive liquid waste are discharged by the ORANO La Hague nuclear fuel reprocessing plant (RP). Radionuclides were monitored in the NBG to assess the dispersion of radioactive discharges from the RP in the marine environment. The temporal and spatial distribution of the data are consistent with the history of the discharges, with most gamma emitter radionuclide environmental levels being close to or below the current limits of detection. A clear fingerprint of H-3, C-14 and I-129 radionuclides discharged from the RP is measured. The hydrodynamics in the NBG do not yield a simple gradient with linear distance from the outfall of the RP. Modelling tools were used to understand how radioactive discharges spread from the source of input. Dispersion patterns clearly illustrate the different behaviours of soluble and non-soluble radionuclides. The study indicated that the footprint of radioactive liquid discharges by French nuclear facilities was still measurable in species collected from the NBG for the mostly dissolved radionuclides. The less conservative ones, with a high affinity for suspended matter, are potentially influenced by old releases. These pathways could be investigated by dedicated hydrodynamic dispersion models. Overall, in the Channel Islands the levels are low and consistent with the general decrease in liquid radionuclide discharges by the RP since the 1990s.
海峡群岛位于诺曼底-布列塔尼海湾（NBG），英吉利海峡中部（法国，诺曼底）。在北部，拉阿格角附近，奥瑞那（ORANO）拉阿格核燃料后处理厂（RP）有控制地排放放射性液体废物。为了评估放射性排放物在海洋环境中的分散情况，在 NBG 监测了放射性核素。数据的时间和空间分布与排放物的历史一致，大多数伽马发射体放射性核素的环境水平接近或低于当前检测极限。从 RP 排放的 H-3、C-14 和 I-129 放射性核素的明显指纹被测量到。NBG 中的水动力不会产生与从 RP 排放口的线性距离相对应的简单梯度。建模工具用于了解放射性排放物如何从输入源扩散。分散模式清楚地说明了可溶性和不可溶性放射性核素的不同行为。该研究表明，对于从 NBG 采集的物种，来自法国核设施的放射性液体排放的足迹仍然可以测量到大多数溶解放射性核素。那些与悬浮物亲和力高、不太保守的放射性核素可能受到旧释放物的影响。这些途径可以通过专门的水动力弥散模型进行研究。总体而言，在海峡群岛，水平较低，与自 20 世纪 90 年代以来 RP 放射性液体排放量普遍减少相一致。
