Detecting Nuclear Materials Smuggling: Performance Evaluation of Container Inspection Policies

Abstract

In recent years, the United States, along with many other countries, has significantly increased its detection and defense mechanisms against terrorist attacks. A potential attack with a nuclear weapon, using nuclear materials smuggled into the country, has been identified as a particularly grave threat. The system for detecting illicit nuclear materials that is currently in place at U.S. ports of entry relies heavily on passive radiation detectors and a risk-scoring approach using the automated targeting system (ATS). In this article we analyze this existing inspection system and demonstrate its performance for several smuggling scenarios. We provide evidence that the current inspection system is inherently incapable of reliably detecting sophisticated smuggling attempts that use small quantities of well-shielded nuclear material. To counter the weaknesses of the current ATS-based inspection system, we propose two new inspection systems: the hardness control system (HCS) and the hybrid inspection system (HYB). The HCS uses radiography information to classify incoming containers based on their cargo content into "hard" or "soft" containers, which then go through different inspection treatment. The HYB combines the radiography information with the intelligence information from the ATS. We compare and contrast the relative performance of these two new inspection systems with the existing ATS-based system. Our studies indicate that the HCS and HYB policies outperform the ATS-based policy for a wide range of realistic smuggling scenarios. We also examine the impact of changes in adversary behavior on the new inspection systems and find that they effectively preclude strategic gaming behavior of the adversary.

Using container inspection history to improve interdiction logistics for illicit nuclear materials

“…The choices of the above parameters are consistent with those used in previous studies, for example in Wein et al [23] and Gaukler et al [9,10]. To the best of our knowledge, these parameter choices reflect a reasonable setup and operation of the inspection steps at a port.…”

“…The delay time can be computed through modeling the queueing network associated with the inspection processes, and is a function of the arrival rates and false alarm probabilities at each node. This queueing network model has been developed and described in detail in earlier research; for details, please refer to Gaukler et al . The second constraint is on the utilization rate at the manual node, denoted by .…”

“…The current literature and practice, however, primarily focus on proposing and analyzing inspection policies at a single port, using detection data obtained at the very same port. The current research can be largely grouped under two categories: the tactical problem, which is to find the optimal inspection policy under delay time and/or budget constraints [7,9,10,14,23,24], and the strategic problem, which is to decide the locations of inspection stations and detectors along a long border, assuming that the inspection policy at each station is given [6,16,17]. We are not aware of any tactical problems that involve the use of container inspection history.…”

“…. At each port, the container goes through a layered inspection system, different varieties of which have been described in the literature . In this article, we consider an inspection system comprised of four detection components: the intelligence‐based‐automated target system (ATS), radiography equipment (such as X‐ray machines), passive radiation detection equipment [radiation portal monitors (RPM)], and manual inspection (namely, opening up a container and doing item‐by‐item manual search).…”

Lesson learned from the recovery of an orphan source inside a maritime cargo: analysis of the nuclear instrumentations used, and measures realized during the operations

“…The illegal introduction of RN materials can also provoke serious economic consequences which may involve a large fraction of the national emergency system [34]. While several actions have been taken into consideration at a political, managerial and technological level [16,17,25], a comprehensive cooperation between the relevant authorities is still missing; moreover, the existing reluctance of the shippers and harbor operators to a e-mail: malizia@ing.uniroma2.it (corresponding author) 0123456789(). : V,-vol implement effective inspection regimens (which may delay the shipments) could cause a RN emergency situation [20].…”