Measuring Very Low Radiation Doses in PTFE for Nuclear Forensic Enrichment Reconstruction

TL;DR

This paper demonstrates that calorimetric signatures in PTFE can be used to detect and reconstruct past uranium enrichment activities with high sensitivity, aiding nuclear forensic verification.

Contribution

It introduces a novel calorimetric method to detect low-level radiation signatures in PTFE for nuclear forensic reconstruction, surpassing previous detection sensitivities.

Findings

Detectable calorimetric signatures in PTFE from uranium alpha emissions.

Ability to reconstruct past enrichment activities with high sensitivity.

Fast scanning calorimetry confirms radiation exposure and detects tampering.

Abstract

Every country that has made nuclear weapons has used uranium enrichment. Despite the centrality of this technology to international security, there is still no reliable physical marker of past enrichment that can be used to perform forensic verification of historically produced weapons. We show that the extremely low radioactivity from uranium alpha emissions during enrichment leaves detectable and irreversible calorimetric signatures in the common enrichment gasket material PTFE, allowing for historical reconstruction of past enrichment activities at a sensitivity better than one weapon's quantity of highly enriched uranium. Fast scanning calorimetry also enables the measurement of recrystallization enthalpies of sequentially microtomed slices, confirming the magnitude and the type of radiation exposure while also providing a detection of tampering and a method for analyzing field samples useful for treaty verification. This work opens the door for common items to be turned into precise dosimeters to detect the past presence of radioactivity, nuclear materials, and related activities with high confidence.