Photonuclear-based Detection of Nuclear Smuggling in Cargo Containers

Jones, James L.; Haskell, K.J.; Hoggan, J. M.; Norman, D.R.; Yoon, W.Y.

doi:10.1063/1.1619865

Cited by 7 publications

(9 citation statements)

References 2 publications

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“…Among nuclear weapons the 239 Pu components have weak but sometimes detectable radioactive emissions and they may be detectable using passive nuclear techniques, though detection is not reliable. On the other hand, 235 U in the form of "highly enriched uranium" (HEU) components have only weak, low-energy gray emissions [8], with principal emission at 185 keV, that are severely attenuated by even small cargo over-burden so that they are nearly impossible to detect using passive nuclear techniques. This problem is even more difficult because natural radioactive decay of 235 U produces negligible neutron emission (~ 0.006 n/s per kg) [9].…”

Section: Fig 11 a Loaded Container Ship At Port Of Oaklandmentioning

confidence: 99%

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

Manatt¹,

Sleaford²,

Schäffer³

et al. 2004

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The goal of our research was to address the problem of detection of weapons of mass destruction (WMD) materials within containers in common use on commercial cargo trafficking. LLNL has created an experimental test bed for researching potential solutions using (among other techniques) active interrogation with neutrons. Experiments and computational modeling were used to determine the effectiveness of the technique.Chemical weapons materials and high explosives can be detected using neutron activation and simple geometries with little or no intervening material. However in a loaded container there will be nuisance alarms from conflicting signatures resulting from the presence of material between the target and the detector (and the interrogation source). Identifying some elements may require long counting times because of the increased background. We performed some simple signature measurements and simulations of gamma-ray spectra from several chemical simulants. We identified areas where the nuclear data was inadequate to perform detailed computations.We concentrated on the detection of SNM in cargo containers, which will be emphasized here. The goal of the work reported here is to develop a concept for an active neutron interrogation system that can detect small targets of SNM contraband in cargo containers, roughly 5 kg HEU or 1 kg Pu, even when well shielded by a thick cargo. It is essential that the concept be reliable and have low false-positive and false-negative error rates. It also must be rapid to avoid interruption of commerce, completing the analysis in minutes.A potentially viable concept for cargo interrogation has been developed and its components have been evaluated experimentally. A new radiation signature unique to SNM has been identified that utilizes high-energy, fission-product gamma rays. That signature due to g-radiation in the range 3-6 MeV is distinct from normal background radioactivity that does not extend above 2.6 MeV. It's short half-life of 20-55 sec makes it distinct from neutron activation due to the interrogation that is typically much longer lived. This work spawned a collaboration with LBNL where experiments verified the abundance and other characteristics of this new signature [24]. Follow-on work funded by DoE/NA22 led to the development of a detailed system concept and evaluation of its impact on operating personnel and cargos [60] and characterization of one important interference that was identified [61]. The follow-on work led to two patent applications at LBNL and LLNL. The signature flux, while small, is 2-5 decades more intense than delayed neutron signals used and facilitates the detection of SNM even when shielded by thick cargo. The actual benefit is highly dependent on the type and thickness of cargo, with modest benefit in the case of metallic cargos of iron, lead, or aluminum, but maximum benefit in the case of hydrogenous cargo. In addition, unwanted collateral effects of the interrogation, such as neutron activation of the cargo, were analyzed [60] and one sign...

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Section: Fig 11 a Loaded Container Ship At Port Of Oaklandmentioning

confidence: 99%

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

Manatt¹,

Sleaford²,

Schäffer³

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Among nuclear weapons the 239 Pu components have weak but sometimes detectable radioactive emissions and they may be detectable using passive nuclear techniques, though detection is not reliable. On the other hand, 235 U in the form of "highly enriched uranium" (HEU) components have only weak, low-energy γray emissions [8], with principal emission at 185 keV, that are severely attenuated by even small cargo over-burden so that they are nearly impossible to detect using passive nuclear techniques. This problem is even more difficult because natural radioactive decay of 235 U produces negligible neutron emission (~ 0.006 n/s per kg) [9].…”

Section: Fig 11 a Loaded Container Ship At Port Of Oaklandmentioning

confidence: 99%

Detection of Special Nuclear Material in Cargo Containers Using Neutron Interrogation

Slaughter¹,

Accatino²,

Bernstein³

et al. 2003

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“…Following fission, both prompt neutrons and rays are released. At much later times as a result of -decay of the fission products, very characteristic delayed neutrons [2]- [5] and rays are emitted. The prompt radiations are hard to detect because of the overwhelming abundance of neutrons and rays produced by the interrogation beam.…”

Section: Introductionmentioning

confidence: 99%

The "nuclear car wash": a scanner to detect illicit special nuclear material in cargo containers

et al. 2005

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There is an urgent need to improve the reliability of screening cargo containers for illicit nuclear material that may be hidden there for terrorist purposes. A screening system is described for the detection of fissionable material hidden in maritime cargo containers. The system makes use of a low-intensity neutron beam for producing fission and the detection of the abundant high-energy rays emitted in the -decay of short-lived fission products and -delayed neutrons. The abundance of the delayed rays is almost an order of magnitude larger than that of the delayed neutrons normally used to detect fission, and they are emitted on about the same time scale as the delayed neutrons, i.e., 1 min. The energy and temporal distributions of the delayed rays provide a unique signature of fission. Because of their high energy, these delayed rays penetrate low-Z cargoes much more readily than the delayed neutrons. Coupled with their higher abundance, the signal from the delayed rays escaping from the container is predicted to be as much as six decades more intense than the delayed neutron signal, depending upon the type and thickness of the intervening cargo. The rays are detected in a large array of scintillators located along the sides of the container as it is moved through them. Measurements have confirmed the signal strength in somewhat idealized experiments and have also identified one interference when 14.5-MeV neutrons from the D, T reaction are used for the interrogation. The interference can be removed easily by the appropriate choice of the neutron source.Index Terms-Active interrogation, delayed fission product radiation, neutron irradiation, shielded special nuclear material.

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Photonuclear-based Detection of Nuclear Smuggling in Cargo Containers

Cited by 7 publications

References 2 publications

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

Detection of Special Nuclear Material in Cargo Containers Using Neutron Interrogation

The "nuclear car wash": a scanner to detect illicit special nuclear material in cargo containers

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