我国近海海域海水中的钚核素 - 水平、分布及同位素比值测量研究

钚核素是与核军工和核工业密切相关的敏感核素。今天环境中存在的钚核素主要来源于上世纪大气层核爆试验及核反应堆事故释放等人类核活动，钚核素以痕量或超痕量水平存在于环境中。和陆地土壤中钚的环境行为不同，海洋环境中钚会随洋流路径远距离迁移扩散。我国近海属于西北太平洋海域，该海域钚除全球沉降外，还明显受美国太平洋PPG核试验场影响。目前我国核电事业发展迅速，核电厂全部位于沿海地区，针对我国近海海域，开展海水中此“准本底”核素测量研究，可以阐明钚核素海洋环境行为，为我国核电厂反应堆安全运行评价和核事故应急准备奠定基础。.本项目拟建立基于电感耦合等离子质谱仪（ICP-MS）的海水中钚核素精确测量方法，测量239+240Pu和240Pu/239Pu；以位于渤海、黄海、东海和南海的15处核电基地近海30公里表层海水为研究对象，开展系统测量研究，填补完善我国近海海域数据，为今后核设施安全评价提供工具。

Plutonium nuclides are sensitive nuclides that have been in a close relationship with nuclear military and industry. Today, plutonium nuclides existing in the environment at trace or ultra-trace level were mainly released from a series of nuclear weapon tests conducted in last century and nuclear reactor accidents. Differing from their environmental behavior in terrestrial environment, plutonium in marine environment would go through long-distance transportation and diffusion along the current path. Chinese coastal water is part of western North Pacific, where plutonium inventory was not only received from the global fallout but also significantly impacted by the regional pollution from U.S. Pacific Proving Ground (PPG). For our nation, nuclear industry has been growing rapidly nowadays and all of the nuclear power plants are distributed in coastal regions. Hence, significant demand rises in recent years for the development of research focusing on the quasi-background level investigation of nuclides in Chinese coastal seawaters, which would help to illustrate the oceanographic behavior of plutonium and also build a foundation for the safety evaluation of nuclear power plants and emergent response to nuclear accidents..This project is planned to build a precise method for the determination of plutonium nuclides in seawater by inductively coupled plasma mass spectrometry (ICP-MS), and has surface seawaters sampled around 15 Chinese nuclear power bases to be the research objects. 239+240Pu concentration and 240Pu/239Pu atom ratio would be systematically determined for Bohai, Yellow Sea, East China Sea and South China Sea, i.e. all the 4 sea areas around China. The results could supplement the background dataset of radiological nuclides in China, and further offer support for the safety evaluation of nuclear power industry.