Nuclear Forensics: A Holistic Overview

Discussions of nuclear forensics are often restricted to work performed by radiochemists measuring nuclear material attributes in the laboratory. However, this represents only one portion of the work required to answer critical questions. Laboratory analysis results in measurements that need to be evaluated. The results of those evaluations must be put into their proper context in to be useful to others and often require merging those results with additional information. This may contribute to attribution, by virtue of inclusion or exclusion. Finally, the end product must be presented such that appropriate actions can be taken. This could include prosecution by law enforcement, policy initiatives on the part of legislative bodies, or military action in the case of nuclear attack (whether that attack is preempted or not). Using the discovery of a sample of plutonium during cleanup activities at Hanford in 2004, we will step through the process of discovery (representing an interdiction), initial field analysis, laboratory analysis, data evaluation and merging with additional data (similar to law enforcement and/or intelligence information), thereby providing an example of an integrated approach. A detailed description of the sample, laboratory measurements performed, and data evaluation (including reactor physics modeling) has previously been published (Schwantes et al. 2009). This paper references that sample as an exemplar in describing the forensic process, because it has been so well documented. This paper utilizes results documented in the reference and does not present any new technical findings dealing with that sample.