G.M. Gaukler, C. Li, R. Cannaday, S.S. Chirayath, and Y. Ding,
"Detecting Nuclear Materials Smuggling: using Radiography to improve Container Inspection Policies,"
Annals of Operation Research
, 187(1), 65-87 (2011).
This paper proposes a layered container inspection system for
detecting illicit nuclear materials using radiography information.
We argue that the current inspection system, relying heavily on the
Automated Targeting System (ATS) and passive radiation detectors,
is inherently incapable of reliably detecting shielded radioactive
materials, especially highly enriched uranium (HEU). This motivates
the development of a new inspection system, which is designed to
address a fundamental flaw of the ATS-based system, allowing for
improved defense against sophisticated adversaries. In the proposed
inspection system, all cargo containers go through x-ray imaging
equipment first. From the x-ray image, a hardness measure of the
container is computed. This hardness measure characterizes how
likely it is that shielded HEU, if it does exist in the container,
will not be detected in a subsequent passive detection step.
Depending on the value of the hardness, the lower-hardness
containers are sent to passive detection and the high-hardness
containers are sent directly to active detection. This paper
explores the trade-off between the detection probability of the new
inspection system and the expected sojourn time a container spends
in the system. The solution details and decision-making tools for
using such a system are provided. Comparisons are made between the
proposed system and the current ATS-based nuclear inspection
Associated Project(s):SHIELD (Smuggled HEU Interdiction through Enhanced anaLysis and Detection): A Framework for Developing Novel Detection Systems Focused on Interdicting Shielded HEU