Deployment of Transportable Radiation Monitoring Systems (TRMS) in Inter-modal Transportation Corridors

Background
The U.S. Department of Homeland Security’s Domestic Nuclear Detection Office’s (DNDO) mission is to develop, acquire, and support the deployment of a domestic system to detect and report attempts to import, assemble, or transport a nuclear device or fissile or radiological material intended for illicit use. This mission will be carried out, in part, by developing a national nuclear defense-in-depth architecture. To support the development of this national architecture, the Transportation Security Administration (TSA) is sponsoring the Oak Ridge National Laboratory (ORNL) to deploy and field test transportable radiation monitoring systems (TRMS) in an inter-modal transportation corridor(s).

Objectives
The purpose of this project is to facilitate development of a national architecture for radiation detection and response in inter-modal transportation systems by developing and field testing transportable radiation monitoring systems (TRMS) and developing the Concept of Operations (ConOps) for their deployment (Figure 1)

Figure 1. Preliminary Design for TRMS

Specifically, ORNL will be conducting a field operational test (FOT) of the TRMS to detect and respond to inter-modal movements of radiological materials, to assess how they will perform in practice. Performance measures will be used to evaluate TRMS performance in the FOT. Results and evaluation of the system performance in the FOT will be used to finalize a ConOps that will describe the domestic deployment of TRMS, their operation, and appropriate response to alarms.

Radiation Detection System
The TRMS is a self-contained radiation detection system that can be quickly deployed to specific locations throughout the U.S. whenever potential threats on specific transportation corridors or locations are identified.

The TRMS consists of two utility-type trailers (similar to that shown in Figure 2) that contain commercial-off-the-shelf (COTS) radiation detection systems that can detect radiation emitting materials in vehicles, containers, persons or other objects. A system consists of two radiation detection assemblies, one panel in each trailer (as shown in Figure 3). Vehicles and other objects to be screened pass between the two panels.

Figure 2. Utility Trailer Containing One of Two Panels Comprising the TRMS

Figure 3. TRMS Trailers Deployed at East Portal

Radiation detection is done using large-volume, plastic-scintillation detectors located in each trailer. In addition, a spectroscopic system mounted in the main trailer can identify the radiation source (for example, Cesium 137, Cobalt 60, etc.) based on the emitted photons. By combining the two detection systems, decisions can be made quickly and effectively when an alarm occurs. In addition to these gamma radiation systems, each of the two trailers contains a series of neutron detectors to detect neutron radiation emitters such as those found in Special Nuclear Materials.

Each trailer has its own automatic power control center that enables the system to run from line AC power, battery, on-board generator, or from the tow vehicle battery. The main trailer also incorporates a solar cell array to provide a means to charge the on-board battery.

Test Procedures
This project is being conducted in two separate phases so that the accuracy of the TRMS can be categorically determined. Phase 1 test is currently being carried out on the Department of Energy – Oak Ridge Reservation where system performance can be validated with information on shipping and receiving bills of lading. Insights from the Phase 1 test will then be utilized in the Phase 2 test – the FOT. In the FOT, each TRMS will be field tested in a transportation corridor where operations requirements (e.g., times required to complete the inspection, impediment to traffic flow) will be recorded.

The deployment consist of a “Primary” and “Secondary” Inspection Location (PIL and SIL; see Figure 4). Primary inspection provides initial screening in a way that does not significantly restrict the movement of vehicles. Vehicles that activate the TRMS alarm at the PIL are then evaluated at a nearby Secondary Inspection Location (SIL) to identify the radionuclide(s) present. If the identification shows the radionuclides to be innocuous, the information related to the alarm is stored and the vehicle is permitted to proceed. If the identification shows that further investigation is required, the vehicle is inspected further to locate the radiation source, to identify the radionuclides, and to take the appropriate response actions.

Figure 4. Primary and Secondary Inspection Locations (PIL, SIL) for Phase 1 Test.

The TRMS is integrated with appropriate response protocols. Depending on the type and activity of the radionuclide detected, the TRMS will “notify” the Laboratory Superintendent (in the Phase 1 test) or local emergency operations management (EOM) or fire department (in the Phase 2 FOT test) to activate the line of communications.

Test Evaluation and Performance Measures
It is important that the system be easy to use, accurate in detecting radiological materials, have minimal impact on traffic, and help instigate appropriate response protocols depending on the type and activity of the radionuclide detected.

Consistent with existing and/or forthcoming standards, four categories of performance measures are being used to evaluate TRMS: (1) system performance, (2) benefits, (3) costs, and (4) indirect costs.

For more information regarding this project, please contact Pat Hu, Director, ORNL Center for Transportation Analysis, hups@ornl.gov, (865) 946-1349.

Submitted by: Patricia Hu, Center of Transportation Analysis Group

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