我国北方剖面土壤239,240Pu数据集（2014-2016年）

人类核活动如大气核武器试验、核事故、核燃料循环等向环境中释放了大量的人工放射性同位素，导致区域乃至全球环境放射性水平大幅度升高。其中239，240Pu具有高放射性毒性，240Pu/239Pu携带来源指纹信息，因此环境中239，240Pu的来源、水平及环境行为等引起了广泛关注。本研究对我国北方不同环境剖面土壤中的239，240Pu的浓度以及240Pu/239Pu的原子比值进行了准确分析，并在此基础上进行239，240Pu的迁移计算。结果显示我国北方地区整体环境239，240Pu的浓度水平与全球沉降相比无明显升高，239，240Pu的沉积通量处于报告的类似纬度带全球沉降范围内；240Pu/239Pu的原子比值与报道的全球沉降值吻合较好，表明全球沉降是中国北方钚的主要来源，环境放射性水平目前尚处在安全范围。同时利用CDE模型得到的不同土壤剖面中，钚的有效对流速度(0.04 ~ 0.16 cm/y)和有效弥散系数(0.13 ~ 0.41cm /y)存在显著差异，这与地理位置、地形、气候和土壤类型等因素有关。结果表明，与其他类型土壤，特别是荒漠土壤相比，草地土壤中钚的迁移明显缓慢。Human nuclear activities, including atmospheric nuclear weapons tests, nuclear accidents, and nuclear fuel cycles, have discharged substantial amounts of artificial radionuclides into the environment, resulting in a marked increase in regional and even global environmental radioactivity levels. Of these, 239,240Pu possesses high radiotoxicity, and the 240Pu/239Pu atomic ratio carries source fingerprint information, which has led to extensive attention being paid to the sources, concentrations, and environmental behaviors of 239,240Pu in the environment. In this study, we accurately analyzed the concentrations of 239,240Pu and the 240Pu/239Pu atomic ratio in soils from various environmental profiles across northern China, and performed migration calculations for 239,240Pu based on the analytical results. The findings indicate that the overall 239,240Pu concentration levels in the environment of northern China exhibit no significant elevation relative to global fallout, and the deposition flux of 239,240Pu falls within the range of global fallout reported for similar latitude zones. The 240Pu/239Pu atomic ratio aligns well with the globally reported fallout values, suggesting that global fallout is the primary source of plutonium in northern China, and the current environmental radioactivity levels remain within safe limits. Additionally, the effective convection velocities (0.04 – 0.16 cm/y) and effective dispersion coefficients (0.13 – 0.41 cm/y) derived from the CDE model for different soil profiles show significant differences, which are associated with factors such as geographic location, topography, climate, and soil type. The results further reveal that compared to other soil types, particularly desert soils, plutonium migration in grassland soils is significantly slower.