U.S. Department of Energy

Pacific Northwest National Laboratory

Signatures of Underground Explosions

In the event that the International Monitoring System detects an apparent underground explosion that is lacking the necessary radionuclide signatures necessary to confirm a nuclear event, what signatures should be exploited to determine whether the event was a chemical rather than nuclear explosion? The goal of the project is to look for non-traditional signatures that indicate a chemical explosion rather than rely on the absence of nuclear debris to indicate that the event was chemical in nature.


A broad initial list of potential signatures was generated in brainstorming sessions with a panel of subject-matter experts from a breadth of disciplines. These initial thoughts were pared down to likely signature candidates and short documents (white papers) cataloging the potential impact, open questions, and research directions for each signature category were developed. These have been ranked by relevance and mapped to capabilities at the lab, and initial experiments on a few promising topics have begun. An additional effort to document non-traditional signatures collected in prior underground nuclear and chemical explosive tests is also underway.


Discovery of signatures and development of tools that can be used to discriminate underground chemical from nuclear explosions will provide government agencies tools to enhance national and international security. Investigations and experiments into these potential signatures will leverage the science and discovery base at the lab and enhance our capabilities and expertise. Documentation of the process used to explore the initial steps of signature discovery will help guide future projects.

Project Staff: 
Tim White, Sandy Thompson, Alex Stephan, Alex Misner, Ted Bowyer, Karl Pitts
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