Science Inventory

Part 2: Stabilization/Containment of Radiological Particle Contamination to Enhance First Responder, Early Phase Worker, and Public Safety

Citation:

Magnuson, M., T. Stilman, S. Serre, J. Archer, R. James, X. Xia, M. Lawrence, E. Tamargo, H. Raveh-Amit, AND A. Sharon. Part 2: Stabilization/Containment of Radiological Particle Contamination to Enhance First Responder, Early Phase Worker, and Public Safety. Applied Sciences. MDPI, Basel, Switzerland, 12(8):3861, (2022). https://doi.org/10.3390/app12083861

Impact/Purpose:

The application of stabilization technologies to a radiologically contaminated surface has the potential for reducing spread of contamination and, as a result, decreasing worker exposure to radiation. Three stabilization technologies, calcium chloride (CaCl2), flame retardant Phos-Chek® MVP-Fx, and Soil2OTM were investigated to evaluate the ability to reduce the resuspension and tracking of radiological contamination during site operations such as vehicle and foot traffic. Concrete pavers, asphalt pavers, and sandy soil walking paths were used as test surfaces, along with simulated fallout material (SFM) tagged with radiostrontium (Sr-85) applied as contaminant. Radiological activities were measured using gamma spectrometry before and after simulated vehicle operation and foot traffic experiments, conducted with application of each stabilization technology and without application, as a non-stabilized control. These measurements provided data describing the extent of SFM removed from each surface (onto the tires or boots), the extent of SFM transferred to adjacent surfaces, and the residual SFM remaining on the tires or boots after each experiment. In addition, resuspension of aerosolizable range SFM was monitored during walking path foot traffic experiments. The results are relevant to the planning and implementation of response activities. For instance, the sand surface provided the largest potential for transfer, and overall, in most cases, the stabilization technologies did provide improved stabilization, suggesting the ability to utilize these technologies during foot and vehicle operations. However, there were a few instances where there was no improvement. As for resuspension, during the walking experiments, neither air sample collected during the CaCl2 and Phos-Chek MVP-Fx experiments generated detectable radiological activity, suggesting they decrease the availability of particles respirable by responders.

Description:

During the immediate, emergency phase of a response to a radiological dispersal device (RDD), an improvised nuclear device (IND), or accidental radiological release, emergency responders may be exposed to radioactivity due to inhalation and direct contact. It is important to minimize this exposure, prevent resuspension of contamination, and reduce the tracking/spread of contamination by containing the radioactive materials. The important of reducing resuspension and tracking/spread continues throughout incident recovery. Otherwise hotspots and other focii of recovery operations can physically move, complicating recovery planning and implementation--e.g., efforts could take place for the wrong location. This sub-product includes both methods/equipment for reducing resuspension/tracking/spread and, more importantly for broad application of these methods/equipment, includes user-friendly implementation of the underlying physics.