Diagnostic Radiology Meets Nuclear Terrorism

Diagnostic Radiology Meets Nuclear Terrorism

Frederick W. Nolting, D.D.S., M.S.*:

Readers of Northwest Dentistry continue to tell us that they are interested in the pure science  that not only supports their profession but often springs from it, and that synergy never fails to  contribute to our health, well being, and safety. From continuing contributor on emergency preparedness Rick Nolting comes this enlightening little piece that shows how deep the ramifications of science in the public interest can go.

The Editors

With the threat of nuclear improvised explosive devices, Explosive Ordnance Disposal (EOD)  and the National Nuclear Security Administration (NNSA) have developed a new X-ray imaging application, the X-Ray Toolkit (XTK).1,3 The XTK is a computerized application used in the field  to acquire, process, analyze, and transmit X-ray images during a bomb threat.  XTK will transmit data and images from the field to a bomb squad’s headquarters, the labs at the National  Nuclear Security Administration for investigation, or anywhere else the information is needed. The transfer is seamless and very, very fast. The XTK also can detect nuclear explosive devices.  This  capability makes the system priceless.

XTK is a culmination of 60 years of nuclear security know-how in a package that will be used by  responders across the nation and beyond. Development was a team effort. Input came from  NNSA, Sandia Laboratories, the FBI, the Department of Defense, and  numerous state and local responders. 

XTK has been distributed to select agencies. One with which the author is familiar received its in mid-October 2010. Training with the software commenced immediately.  


XTK software is universal, adapting to all bomb squad imaging softwares. Technicians need  learn only one program, which then adapts to all other systems, as well allowing multiple systems to input data simultaneously. This allows any bomb squad to input data to build a  mosaic picture of a suspicious object in a much faster time frame.  Unlike the “mosaic” pictures generated with film, these images do not have to be fitted by hand, but are accomplished by  the computer, giving a seamless image for the technicians and others to view. Time is a most precious commodity when attempting to defeat a bomb. 

Three-Dimensional Capability

XTK software can generate a 3-D matrix that can be used to precisely aim a disruptor at the  exact spot the bomb would be most vulnerable.4  A disruptor is a device that shoots projectiles at bombs to “disrupt” the firing sequence, thus disarming the bomb. A typical disruptor uses a 12 gauge shotgun charge that fires the device. Various projectiles from solids to columns of water are used. There is no danger of having the aim off by an inch or two. The projectile will be right on target.  

Detecting Nuclear Bombs

The second part of the XTK is the hardware that can detect Nuclear Improvised Explosive  Devices (nuclear bombs). A “black box” with sensing equipment is used to detect gamma radiation. In conjunction with the software, the black box will identify radiation sources by  energy level (wavelength),8 thus differentiating among medical radiation, radiation emitted from power plants, and weapons-grade radiation. The size of these black boxes is a mystery.

Preliminary testing at a Nevada test site in 2006 had small Personal Radiation Detectors (PRD’s) carried by “pedestrians” past radiation sources.5 Radiation sources were then paraded past the detectors to simulate a check point. Other detectors were placed in vans and driven past radiation sources at various speeds and distances. In still another test, CONEX containers (the large steel containers used to ship goods overseas on freighters) were scanned. In yet another scenario, semi trucks were scanned as they passed detectors in weigh stations. 


The testing discussed was documented in 2006.5,6 Currently these studies have raised more questions than they have answered, primarily because many of the answers are in the category “We cannot tell you that”. Among the questions they can answer are: 

How small can an effective PRD be?  Today, there is a creditcard-sized detection device that has been developed and is being refined and tested for the commercial market.9 It uses Tantalum as the detecting element, with  stainless steel filters to eliminate false positives. The filters in a film badge are made of aluminum and copper, which allow for identification of the radiation energy hitting it (KV in the instance of X-radiation). Stainless steel will filter out all of the low-energy gamma rays, leaving only the high-energy, dangerous radiation.   

How sensitive are these detectors?  One article hints that the detectors are so sensitive they can detect radiation from cat litter and blueberries.6 This sensitivity level was a goal in 2006 that has evidently been realized.  

Where can the devices be used?  The preliminary testing articles showed pedestrian models, models for vehicles, and stationary models. It would be the next logical step to equip helicopters and aircraft with the devices. Very large areas could be covered.  

Where can I see one of these devices?  You and I can’t. We might be able to own the personal credit card detector, but I believe it may be like the first GPS units sold to civilians: They could get you within 25-50 feet of a given point, but were, in effect, “dumbed down” from their true capability. Military, bomb squad, and personal detectors will most likely have different capabilities and limitations, to make sure each entity has the most appropriate and capable instrumentation. At the course in Puerto Rico,  there was no mention of the detection side of the XTK;7 it is “just not talked about”.  The web sites I have referenced are public. The information is older and somewhat vague. We will have  to be patient until we are able to see the equipment firsthand. In the meantime, we  acknowledge with gratitude the bomb squads, Sandia Labs, Explosive Ordnance Disposal,  National Nuclear Security Administration, and all of their subcontractors in developing this system. To abridge a famous quote from Ronald Reagan, “Some people wonder all their lives if they’ve made a difference. Bomb squad technicians don’t have that problem.”


1. “Al-Qaida On the Brink of Using Nuclear Bomb”, http://www.vancouversun.com/sports/Qaida%20brink%20using%20nuclear%20bomb/4205104/story.html

2. “FBI Official Sees 100% Likelihood of WMD Strike on U.S., http://www.globalsecuritynewswire.org/gsn/nw_20110217_8935.php

3. NNSA Office of Emergency Operations develops cutting-edge nuclear terrorism software, http://www.nnsa.energy.gov/mediaroom/pressreleases/software

4. Aiming with XTK, http://www.xraytoolkit.com/About.aspx,p.5.

5. Hodge CA, Yuan D, Keegan RP, Krstich MA. Personal radiation detector field test and evaluation campaign. National Security Technologies LLC, DOE/NV/25946—235.

6. NTS uses real-world testing to assess and improve radiological sensors. Site Lines, issue 113, February, 2006, p 1.

7. Gladwell, S. X-ray capability advancements. International Association of Bomb Technicians and Investigators International Meeting, June 13-18, 2010. Puerto Rico, U.S.A.

8. Hodge CA, Keegan RP, Blumenthal D. Radiation Isotope Identification Device (RIIDs) field test and evaluation campaign. National Security Technologies LLC, DOE/NV/25946—


9. A citizen’s radiation dosimeter that fits in the wallet, http://www.medicalnewstoday.com/releases/230327.php

10. Personal communication, Richard F. Nolting, Lead Engineer, GPS Development, Boeing Inc., 1999. 

DX Radiology Link to Nuclear I.E.D.s

The actual link of the X-Ray Toolkit is obvious for the part of the system that takes diagnostic pictures of items suspected of containing a bomb. The phosphor plates and electronic image receptors are just like our digital systems.  

The part that detects Nuclear Improvised Explosive Devices employs the same image receptors that have been used in medical C.A.T. scanners. The receptors are typically cesium iodide crystals or xenon ion chambers. They will record “hits” by gamma ray photons. The software will differentiate the wavelength of the radiation to identify the source material. A tracking system is employed to determine the direction of the source and a system to determine the distance from the source to the detector.  

All of this is placed in a “black box” with a power source. 


*Dr. Nolting is Co-Chair of the Minnesota Dental Association’s Health and Safety Committee. He is a general dentist in private practice in Byron, Minnesota.