某核电厂近岸海域放射性核素迁移特征探讨

发布时间：2018-01-16 00:15

  本文关键词：某核电厂近岸海域放射性核素迁移特征探讨　出处：《海洋科学进展》2016年02期 　论文类型：期刊论文

  更多相关文章： 核电厂 近岸海域 核素迁移 I

【摘要】：滨海核电厂运行时会有少量的放射性核素通过液态途径进入海洋环境中,在掌握其海域水动力环境的基础上,开展放射性核素迁移研究具有重要意义。基于某核电站近岸海域的水下地形和水文条件,通过潮位、流速、流向的率定,构建水动力环境模型,模拟研究区的潮流运动过程和特征,为放射性核素迁移扩散提供基本流场背景。以核素131I为例,采用恒定速率1Bq/L活度浓度持续排放,用实测两个半月潮模拟核素迁移过程,分析放射性核素131I在该海域的时间和空间分布规律。结果表明:1)随着时间推移,核素逐渐向外海域扩散,但扩散速度较慢;随着距离增大,海域中核素活度浓度呈几何倍数快速下降;厂址东北方向岸边核素活度浓度较高,在一个月后逐步达到稳定,约比排放活度浓度低两个数量级。2)涨潮时核素活度浓度范围较小,落潮时核素活度浓度范围快速扩大,相同核素活度浓度面积为涨潮时的2~3倍。3)排放初期,各处核素活度浓度均随时间迅速增加,随后趋于稳定;不同位置的活度浓度随着潮汐交替涨落,不断波动,涨潮时活度浓度较低,落潮时活度浓度较高;不同位置的平均活度浓度随着潮汐交替涨落,不断波动,大潮期间活度浓度较高,小潮期间活度浓度快速降低。
[Abstract]:A small amount of radionuclides will enter the marine environment through liquid way when the coastal nuclear power plant is in operation, on the basis of mastering the hydrodynamic environment of the coastal nuclear power plant. The study of radionuclide migration is of great significance. Based on the underwater topography and hydrological conditions in the coastal waters of a nuclear power plant, the hydrodynamic environment model is constructed by determining the tidal level, velocity and direction. The flow process and characteristics of the studied area are simulated to provide the basic flow field background for radionuclide migration and diffusion. Taking 131I as an example, the constant rate of 1Bq / L activity concentration is used to continuously discharge the radionuclides. The time and spatial distribution of radionuclide 131I in the sea area is analyzed by simulating the radionuclide migration process with two and a half months observed. The results show that the radionuclide gradually diffuses to the outer sea area with the passage of time. But the diffusion rate is slow. With the increase of distance, the concentration of radionuclide activity decreased rapidly. The concentration of radionuclide activity in the northeast direction of the site is relatively high and gradually stabilized after one month, which is about two orders of magnitude lower than the discharge activity concentration. 2) the range of radionuclide activity concentration in the high tide is relatively small. The range of radionuclide activity concentration at the ebb tide expands rapidly, and the area of the same activity concentration is 3 times of that of the rising tide. At the beginning of discharge, the activity concentration of various nuclides increases rapidly with time, and then tends to be stable. The activity concentration at different positions fluctuates continuously with the tide fluctuating alternately. The activity concentration is lower at the high tide and higher at the ebb tide. The mean activity concentration at different positions fluctuates continuously with the change of tide. During the spring tide, the activity concentration is higher, and the activity concentration decreases rapidly during the low tide.
【作者单位】： 环境保护部核与辐射安全中心;
【基金】：科技基础性工作专项——我国环境放射性水平精细图谱建设(2015FY10800)
【分类号】：X771;X55
【正文快照】： 核电厂在正常运行期间,液态放射性流出物与冷却水充分混合后,随冷却水(排水)一起排入受纳水体,从而向水环境排放少量的放射性核素。潜在的放射性物质泄漏污染也是核电厂事故时面临的主要环境问题。2011-03-11,日本福岛第一核电站发生了严重事故,大量放射性物质通过液态途径进，

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