Potential Local to Regional Scale Impacts from Wildfire Re-emission of Hypothetical Radiological Contamination Incidents
Abstract
Radiological release events can potentially contaminate wide areas with radiological materials and decontamination efforts are typically focused on populated areas leaving radionuclides in forested areas for long periods of time. Large wildfires in contaminated forested areas have the potential to reintroduce these radionuclides into the atmosphere and cause exposure risk to first responders and downwind communities. The most notable radionuclide contaminant released from radiological incidents is Cesium-137 due to high yields and long half-life of 30.2 years. High levels of Cesium-137 have been measured in vegetation and litter after the Chernobyl and Fukushima incidents and wildfires have been identified as a mechanism by which this contaminant can be redistributed in the environment.
A Eulerian 3D photochemical transport model was used to estimate potential ambient impacts of Cesium-137 re-emission due to wildfire following hypothetical radiological release scenarios in Denver, CO and Los Angeles, CA. Cesium-137 emissions were based on laboratory measurements that were adjusted to reflect post-incident levels using data collected in a forest near Fukushima. The Community Multiscale Air Quality (CMAQ) model version 5.2 was applied to an area covering northern Colorado and southern California using 4 km sized grid cells and emissions from all known anthropogenic (e.g., vehicles, power plants, etc.), biogenic (vegetation), and geogenic (wildland fire) sources. Emissions from a large wildfire were introduced into the wildland-urban interface (WUI) impacted by a previous hypothetical radiological release event and PM cesium impacts resulting from the hypothetical wildfire were estimated for a variety of meteorological conditions to capture the full potential extent of downwind population exposure. This type of information is intended to provide context for understanding what level of exposure mitigation may be necessary for communities downwind of wildfires in areas of recent radiological contamination and how cleanup of contaminated forested areas should be prioritized compared to urban centers.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A21J2850B
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0340 Middle atmosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES