EDUCATION OF ANALYTICAL METHOD FOR THE MIGRATION STUDY OF ENVIRONMENTAL PLUTONIUM

1945年8月9日在日本长崎引爆了一颗10- 15公斤的钚原子弹。一部分1.2公斤的239钚裂变释放出21千吨的TNT能量沿着各种裂变产物。剩余的未消耗的裂变材料239+ 240 Pu（13.8 kg，3.49 x 10^<13>Bq）与裂变产物137 Cs（23.4 g，7.44 x 10^ Bq）一起沿着散入大气<13>。239+ 240 Pu和137 Cs的命运通过分析本地和全球沉降物进行了研究。239+ 240 Pu的最高浓度为64.5 mBq/g（181 mBq/cm ~ 2），而137 Cs的最高浓度为188 mBq/g（526 mBq/cm ~ 2），均位于距震源以东2.8 km处。239+ 240 Pu和137 Cs在264平方公里的局部沉降区的总沉降量分别为37.5克（9.48 x 10^<10>Bq）和3.14毫克（5.88 x 10^<10>Bq）。当地沉降物占释放的放射性核素总量的比例为239+ 240 Pu的0.27%和137 Cs的0.134%。分析技术的最新进展使人们有可能在1945年北极冰芯层中检测到长崎爆炸释放的人造放射性核素。在加拿大埃尔斯米尔岛的阿加西冰帽上采集了10个冰芯，测量了239+ 240 Pu和137 Cs。239+ 240 Pu的沉积量为0.16 μBq/cm ~ 2，137 Cs的沉积量为20 μBq/cm ~ 2。在大气试验过程中，239+ 240 Pu和137 Cs的沉降变化超过100次，最高峰出现在1962年，239+ 240 Pu超过50 μBq/cm ~ 2，137 Cs超过800 μBq/cm ~ 2。分析北极数据，有许多新的信息，长期的全球运输，核武器的发展历史等。

An artificial single dose contaminant was released at Nagasaki, Japan on August 9,1945 detonating Plutonium (10-15kg) atomic bomb. A portion, 1.2 kg of 239Pu was fissioned releasing 21 kt TNT energy along with various fission products. The rest of the unexpended fissile material, 239+240Pu, 13.8 kg (3.49 x 10^<13> Bq), was dispersed into the atmosphere along with a fission product, 137Cs, 23.4 g (7.44 x 10^<13>Bq). The fate of 239+240Pu and 137Cs was investigated by analysing both local and global fallout. The highest concentration of 239+240Pu was 64.5 mBq/g (181 mBq/cm2) while it was 188 mBq/g (526 mBq/cm2) for 137Cs both at 2.8 km east from the hypocentre. The total amount of deposition in the local fallout region of 264 km2 was 37.5 g (9.48 x 10^<10>Bq) for 239+240Pu and 3.14 mg (5.88 x 10^<10>Bq) for 137Cs. The ratio of the local fallout against the total amount of the radionuclides released was 0.27% for 239+240Pu and 0.134% for 137Cs. Recent advancements in analytical technology made it possible for artificial radionuclides released from the Nagasaki explosion to be detected in the Arctic ice core layer of 1945. The 239+240Pu and the 137Cs, were measured by collecting 10 ice cores on the Agassiz ice cap, Ellesmere Island, Canada. The deposition was 0.16 μBq/cm2 for 239+240Pu and 20 μBq/cm2 for 137Cs. During the atmospheric testing, the deposition of 239+240Pu and 137Cs varied more than 100 times with the highest peaks of over 50 μBq/cm2 for 239+240Pu and over 800 μBq/cm2 for 137Cs both occurred in 1962. Analyzing Arctic data, there are many new information for long global transport, the history of nuclear weapons development etc.