Schwantes Jon M, Douglas Matthew, Bonde Steven E, Briggs James D, Farmer Orville T, Greenwood Lawrence R, Lepel Elwood A, Orton Christopher R, Wacker John F, Luksic Andrzej T
Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, USA.
Anal Chem. 2009 Feb 15;81(4):1297-306. doi: 10.1021/ac802286a.
During World War II, the Hanford Site in Washington became the location for U.S. plutonium production. In 2004, a bottle containing a sample of plutonium was recovered from a Hanford waste trench. Here, state-of-the-art instrumental analyses, reactor model simulations, and investigative science techniques were used to provide insights as to the origin of this unknown sample, a process collectively termed as nuclear archeology. Isotopic age dating conducted on the sample in 2007 indicated the sample was separated from the spent fuel 61.6 +/- 4.5 years earlier. The isotope (22)Na, a detectable product of a secondary nuclear reaction, proved useful as a powerful tool for nuclear forensic analysis as (1) an easily detectable signifier of the presence of alpha emitting actinides, (2) an indicator of sample splitting, and (3) a measure of the time since sample splitting. Analytical results of minor actinide isotopes and reactor model simulations confirmed the material originated from the X-10 reactor in Oak Ridge, TN. Corroborated by historical documents, we concluded this sample was part of the first batch of Pu separated at T-Plant, Hanford, the world's first industrial-scale reprocessing facility, on December 9, 1944. This sample represents the oldest known collection of man-made (239)Pu in the world.
第二次世界大战期间，华盛顿州的汉福德基地成为美国钚的生产地。2004年，从汉福德的一个废料沟中找回了一个装有钚样本的瓶子。在此，运用了最先进的仪器分析、反应堆模型模拟和调查科学技术，以深入了解这个未知样本的来源，这一过程统称为核考古学。2007年对该样本进行的同位素年龄测定表明，该样本在61.6±4.5年前从乏燃料中分离出来。同位素22Na是一种二次核反应的可检测产物，被证明是核法医分析的有力工具，因为它（1）是存在发射α粒子锕系元素的易于检测的标志，（2）是样本分裂的指标，（3）是样本分裂后时间的度量。次要锕系元素同位素的分析结果和反应堆模型模拟证实，该物质源自田纳西州橡树岭的X-10反应堆。经历史文件证实，我们得出结论，该样本是1944年12月9日在世界上第一个工业规模后处理设施——汉福德T厂分离出的第一批钚的一部分。这个样本代表了世界上已知最古老的人造钚集合。
