摘要: |
系统调研美国温排水法规标准体系、混合区政策以及滨海核电厂混合区的设置, 并与我国现状进行比较。可以看出, 美国清洁水法和联邦法规给出温排水和水质标准的一般要求, 各个州的水质标准给出水质准则、混合区政策以及对水生生物保护的要求。水质准则给出各种类型水体温度限值(包括温升限值和/或温度上限值); 混合区政策给出混合区的位置、尺寸、形状以及混合区内水质要求; 具体厂址应基于“一事一议”的方式确定混合区范围, 并满足混合区最小化要求, 大部分美国滨海核电厂混合区范围满足州的混合区政策要求; 少数核电厂混合区范围超过了州混合区政策要求, 这些电厂需进行厂址特性热影响研究, 以证明当前的温排水限值能够确保受纳水体中结构稳定的土著贝类、鱼类和其他野生生物种群的生长和繁育。我国当前没有地区差异的水质准则, 无温排水混合区政策、设置方法或导则。美国温排水混合区设置方法和实践有助于我国滨海核电厂温排水混合区的设置和优化, 以减小对水生生物的影响。 |
关键词: 核电厂 温排水 混合区 水质标准 水生生物 |
DOI:10.11759/hykx20170222001 |
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Insights on the development of thermal discharge mixing zones from U.S. nuclear power plants in coastal regions |
WEI Xin-yu,ZHANG Kun,WANG Shao-wei,XU Hai-feng,FANG Yuan,YANG Duan-jie
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Abstract: |
In this study, we investigated U.S. acts, regulations, standards, and policies with respect to thermal discharge and mixing zones and their applications to U.S. nuclear power plants in coastal regions, which we then compared with current Chinese situations. We found that general requirements regarding thermal discharge are provided by the U.S. Clean Water Act and the Code of Federal Regulations. The water quality standards for each state contain water quality criteria, mixing zone policies, and the requirements for the protection of aquatic biota. Water quality criteria include temperature limits (temperature increases and/or maximum temperatures) for various types of water. U.S. state mixing zone policies describe mixing zones in terms of location, maximum size, shape, and in-zone water quality. Individual mixing zones for specific discharges are defined on a case-by-case basis using the state mixing zone policies, and must ensure that the mixing zone size is minimized. Most thermal discharge mixing zones from U.S. nuclear power plants in coastal regions meet their respective mixing zone policies. For those unable to meet the mixing zone standards, site specific studies are conducted to determine the impacts of the thermal discharges to ensure the projection and propagation of balanced, indigenous populations of shellfish, fish, and wildlife in and on the body of water into which the discharge occurs. In China, there are no regional differences in water quality criteria and there are no policies, implementation methods, or guidelines for mixing zones. Therefore, the U.S. development of methods and practical experiences for thermal discharge mixing zones can help in the development and optimization of strategies for the thermal discharge mixing zones of Chinese nuclear power plants, thereby reducing the impacts on aquatic biota. |
Key words: Nuclear power plant Thermal discharge Mixing zone Water quality standard Aquatic biota |