本研究旨在模擬輻射塵在大氣中的傳送行為與分布情形及對台灣之影響評估，針對東亞核電廠進行氣流軌跡模擬，結果顯示中國廣東大亞灣核電廠與上海秦山核電廠氣流較易影響台灣，到達台灣機率為7-12%，到達台灣時間為46小時左右；韓國與日本南部之核電廠，氣流到達台灣之機率為10%，平均到達台灣之時間約為72小時。由季節頻率分布結果顯示中國南方核電廠與中國北方、韓國、日本等核電廠氣流影響台灣分別集中在春夏季與秋冬季，亞洲季風是主宰大氣擴散之主因。嚴重核事故情境之全年模擬顯示，中國核電廠輻射塵影響台灣機率為50-70%之間，台灣北部地區平均輻射沉降量約為103 Bq m^(-2)以上，其輻射塵經過20-30小時即可到達台灣。當梅雨鋒面經過台灣時，若中國大亞灣核電廠發生嚴重核事故，則台灣北部地區大約在第48小時左右將承受10^4-10^5 Bq m^(-2)之Cs-137 輻射塵沉降量；秦山核電廠輻射塵沉降至台灣的天氣型態為大陸冷高壓位於黃河河套，且事故當時無降水之際，估計最快到達台灣時間為一日之內，沉降區域涵蓋台灣60%之陸地。

This study is aimed to simulating the transport and dispersion of radioactive dust using an atmospheric transport model, and further to assess its impact on Taiwan. Based on 2001 ECMWF meteorological data, we characterized the forward trajectories of airflows originating from 10 nuclear power plant stations in East Asia, and also calculated the frequency of contaminated airflows arriving in Taiwan. The results showed that the airflow from the Qinshan power plant station in China has the highest frequency of 12% reaching Taiwan, and the average travel time is about 2 days. For the airflow from Korea and Japan, the frequency is about 10%, and travel time is within three days. The airflow arriving in Taiwan is strongly associated with Asian Monsoon. A yearly simulation for the serious nuclear accident in Qinshan and Guangdong power plants was conducted. The results showed that Taiwan is located within a of 50-70%, the average Cs-137 deposition in northern Taiwan is about 103 Bq m^(-2) and travel time is within 20-30 hours. For the case of a frontal passage over northern Taiwan, 10^4-10^5 Bq m^(-2) was obtained within 25 hours. In contrast, when Qinshan nuclear power plant occurred severe accident in the case of northeast monsoon, radioactive dust can reach Taiwan within 1 day and cover the 60% of Taiwan land.