Publications

Aug, 2026

Journal

Stochastic expansion of radionuclide inhalation dosimetry for consequence management application: uncertainty and sensitivity analysis in the ICRP 130 human respiratory tract model

Releases from nuclear or radiological security events can result in significant internal radiation contamination through inhalation of particulate contaminants. The reference human respiratory tract model (HRTM), developed by the International Commission on Radiological Protection (ICRP) and described in the ICRP Publication 66 with subsequent updates in the ICRP Publicati…

Feb, 2026

ORNL Report

Developing Source Term Database for Advanced Reactors

Aug, 2025

Journal

Development of a military-specific mesh-type computational phantom library and its application to internal dosimetry and in-field radiological triage screening

Estimates of organ-absorbed and committed doses to individuals exposed to radioactive materials via acute inhalation often rely on internal dose coefficients and detector responses from reference human computational models. To achieve more accurate dose assessments to United States Armed Forces service members exposed in-field, computational models with varying morphometri…

Aug, 2024

Conference Paper

Physics-Based Machine Learning Methods for U-235 Forensics Signatures

Signatures of low-intensity U-235 sources have been recently studied by utilizing a variety of machine learning (ML) classifiers using features derived from gamma spectral measurements collected under structured campaigns. Several ML classifiers, such as ensemble of tress and classification trees, revealed misleadingly-optimistic training error due to over-fitting, and fur…

Aug, 2024

Journal

Weather radar utility in hazard detection and response

Publicly accessible weather radar data have significant capabilities for meteorological measurements and predictions and, further, have the potential to measure nonmeteorological events that include smoke, ash, and debris plumes as well as explosions. The ability to identify and track nonmeteorological events can be of assistance in emergency response, hazard mitigation, a…

Jul, 2024

ORNL Report

Samoa Updater: An Application of the Levenberg-Marquardt Method to Update Delfic Predictions Using Field Measurements

Dec, 2023

Conference Paper

On Feature, Classifier and Detector Fusers for 235U Signatures Using Gamma Spectral Counts

Three types of information fusion strategies are studied to assess the performance of classifiers for detecting low-level 235 U radiation sources, using features obtained from gamma spectra of NaI detectors. These three strategies are based on using two spectral region features, fusing eight classifiers of diverse designs, and fusing multiple detectors located at different…

Dec, 2023

Conference Paper

Estimation of Optical Channel Signal Loss Following a Near-Surface Nuclear Detonation

We estimate the loss penalty for a free-space, ground to low earth orbit optical communications channel due to lofted atmospheric debris following a nuclear weapon explosion. These losses were estimated over time and compared to other loss sources like clouds and wildfire haze.

Nov, 2023

Conference Paper

Effects on Communications Wavelengths from an Atmospheric Nuclear Detonation

We model the elevated free electron density of the atmosphere from a nuclear detonation as a function of time and examine how the electromagnetic spectrum is affected.

Nov, 2023

Journal

Space-based quantum networking in the presence of a nuclear disturbed environment

Space-based quantum networks provide a means for near-term long-distance transmission of quantum information. This article analyzed the performance of a downlink quantum network between a low-Earth-orbit satellite and an observatory operating in less-than-ideal atmospheric conditions. The effects from fog, haze, and a nuclear disturbed environment on the long-range distrib…

Nov, 2023

Conference Paper

Selection of Training Sets for 235U Source Detection Classifiers Using Gamma Signatures

The machine learning methods for classifiers to detect low level radiation sources are of interest when suitable training data sets are available. Their application and performance assessment, however, involves the aspects of over-fitting and training data selection that are somewhat uncommon in other existing methods for this task. We study U-235 gamma signatures using da…

Nov, 2023

Conference Paper

On Feature, Classifier and Detector Fusers for U-235 Signatures Using Gamma Spectral Counts

Three types of information fusion strategies are studied to assess the performance of classifiers for detecting low-level U-235 radiation sources, using features obtained from gamma spectra of NaI detectors. These three strategies are based on using two spectral region features, fusing eight classifiers of diverse designs, and fusing multiple detectors located at different…