Saito-Kokubu Y, Esaka F, Yasuda K, Magara M, Miyamoto Y, Sakurai S, Usuda S, Yamazaki H, Yoshikawa S, Nagaoka S
Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
Appl Radiat Isot. 2007 Apr;65(4):465-8. doi: 10.1016/j.apradiso.2006.10.010. Epub 2006 Dec 5.
The source of plutonium in sediments deposited at Nishiyama reservoir at Nagasaki was characterized by their (240)Pu/(239)Pu atom ratio. The average ratio was approximately 0.03, except in two layers. The main source of the plutonium was the Nagasaki atomic bomb. The plutonium continues to flow into the reservoir even now. The (240)Pu/(239)Pu atom ratios in two layers were higher than the average, which showed that plutonium in these layers were made of those of nuclear tests added to those of the atomic bomb.
通过钚的（240）Pu/（239）Pu原子比来表征长崎西山水库沉积物中钚的来源。除两层外，平均比值约为0.03。钚的主要来源是长崎原子弹。即使现在钚仍在持续流入水库。两层中的（240）Pu/（239）Pu原子比高于平均值，这表明这些层中的钚是由原子弹的钚与核试验的钚组成的。
