What has been stolen
What was stolen was a density gauge that used a nuclear isotope, it was taken from an industrial site in Jackson County, Mississippi, USA, on 15 February 2019. The gauge, which harmful contains radioactive material, was in a yellow outer carry case when it was stolen.
You can read the full report of the theft here.
And here with some better pictures of the device.
And here is a great article by the EPA describing how these sorts of devices are used: Nuclear Gauges Used in Road Construction.
Why are radioisotopes used in these devices?
Gauges like the one stolen are commonly used to measure the thickness, density or make-up of a wide variety of materials and surfaces: for example, the thickness of tarmac, or cement or the moisture level in the soil. They are incredibly useful but have to be treated with care and disposed of properly if damaged or at the end of their useful life. If used properly they are shielded so do not expose the operator or the public to radiation.
But you don’t want them to be stolen and used improperly or simply used as scrap metal.
And here is a great article by the EPA describing how these sorts of devices are used: Nuclear Gauges Used in Road Construction.
Better security and better reporting
Like similar incidents in Malaysia and elsewhere the authorities involved in the missing nuclear material in Mississippi USA have not said what isotopes are involved but this can have an impact on the level of danger faced by the public or even the thief. Surely the company that owns the device knows what model has been stolen and therefore what isotope ist contains. Modern gamma-ray detectors, like the D3S, can identify isotopes so knowing that the depth gauge contains, for example, caesium-137 can help find the missing device.
D3S NET radiation detector
