基于水文条件的内陆核电厂放射性液态流出物动态排放模拟研究

以某内陆核电厂址为例,选取90%频率环境来流作为设计基准,建立放射性液态流出物排放量与环境流量等比分配的动态排放模式,采用EFDC数学模型作为模拟手段,分析基准年逐月来流过程放射性液态流出物排放分配方式与环境水体中核素浓度变化的关系,模拟常态化实际来流过程中放射性液态流出物动态排放控制条件和水域浓度规律。应用于典型案例,提出瞬时排放量控制上限与环境流量等比例动态分配相结合的动态排放控制方式,并提出瞬时排放量上限的合理取值为3倍年均排放速率。结果表明,该动态排放控制方式可有效降低受纳水域高浓度出现时间,并实现最大峰值浓度合理控制,削弱放射性液态流出物排放对环境水体的影响。这对内陆核电厂排水管理具有重要指导意义。

Simulative study on hydrological condition-based dynamic release of radioactive liquid effluent from inland nuclear power plant

By taking the site of an inland nuclear power plant as the study case，a dynamic release mode for the allocation of both the radioactive liquid effluent release proportional to the ambient flow rate is established by taking the ambient incoming flow occurred in 90% as the design datum，and then the relationship between the variations of the nuclides concentration in the ambient water body and the allocation mode of the radioactive liquid effluent release during the monthly incoming flow of the basic year is analyzed and both the dynamic releasing condition and the law of the concentration in water area of the radioactive liquid effluent during the normalized actual incoming flow are simulated as well by taking the mathematical model—EFDC（Environmental Fluid Dynamic Code）as the simulating method. Applying to the typical case，the dynamic releasing control mode combined with the upper control limit of the instantaneous release and the dynamic allocation proportional to the ambient flow rate is proposed herein，from which it is suggested that the reasonable value taken for the upper limit of the instantaneous release is three times of the annual mean releasing rate. The result shows that this dynamic releasing control mode can effectively reduce the duration of the occurrence of the high concentration of the effluent in its receiving water area，thus realizes the reasonable control of the maximum peak value of the concentration and lower the impact from the radioactive liquid effluent on the ambient water body. This has an important guiding significance for the management of the effluent release from the inland nuclear power plant.