Sydney Nuclear Technologies

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When Steven Newlands was an apprentice at Westinghouse in the early 1980’s, he didn’t think he would be designing, selling, and servicing Nuclear Density Gauges for a living. In 1996, Steve founded Sydney Nuclear Technologies (SN Technologies) in the southern Sydney suburb of Kirrawee and having built his first nuclear isotope housing (Model XP200) in compliance with the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), SN Technologies went on to be a thriving business selling Nuclear Density Gauges to some of the largest companies in the Australian Mining sector.

What are Nuclear Density Gauges?

Industrial gauges that incorporate radioactive sources are used for a variety of purposes, the most common being thickness, level and density gauging and/or control. Other applications include weight and moisture gauging and some analytical procedures. The principle of operation in each case depends on the detection of a beam of radiation transmitted through or scattered by the item or material of interest.

The nucleonic density gauge, as shown in the diagram above (centre), consists of a radioactive source housing (Model XP200 or XR500), which is installed onto pipe mounting hardware and orientated such that the beam passes through the pipeline and the slurry to be measured. On the opposite side of the pipe the radiation is measured by a ‘Scintillation Detector’. The amount of radiation received at the detector is inversely proportional to the density of the slurry. Mass Flow rates (TPH) and Totalization (Tonnes) can be achieved by integrating the density data with data from a volumetric flow meter.


Selling and servicing a product that contains nuclear material has many rewards and certainly many risks as well. The customers installing and using this technology allow their analytical teams to best understand the quality of the material they are dredging or processing. However, there are certainly risks with having an active ‘Beam’ of gamma radiation. One way to mitigate the risks is to move the gauge shutter mechanism to the ‘Beam Off’ position. Once in the ‘Beam Off’ position the shutter can be locked in that position to prevent other personnel from moving the shutter mechanism back to the ‘Beam On’ position, which could cause injury (in the way of harmful doses of gamma radiation) to the maintenance staff working in that area.

“Many of our gauges are installed on dredges in a variety of environments which include salt water, fresh water, in the washeries in coal mines, gold plants down in Tasmania, and many more examples, but typically they are in areas where they can get pretty dirty from dirt, salt, coal dust and so forth,” says Steve Newlands.

Having tried two other master key systems that would typically last under two years out in the field, Steve turned to a local EVVA dealer, Websters Master Locksmiths for a solution. Andrew Webster, saw this as the perfect opportunity to install the SCEC approved SL3 rated products, EVVA 4KS maximum security master key system.

Having the active slider placement in the EVVA 4KS lock cylinders whereby the sliders (springless locking pins) are moved into place by the tracks of the key when inserted, meant Andrew and his team were extremely confident the EVVA 4KS solution would exceed every reliability expectation that Steve had and provide a maximum security solution to protect the nuclear isotopes.

“Having EVVA 4KS incrementally rolling out through our network of nuclear density gauges over the past two years with no reliability issues, means for me, I can concentrate on selling and servicing our gauges to provide the best experience for my clients. No matter how dirty the environment I install these gauges in, the EVVA 4KS system has been up to the task every time,”

– Steve Newlands

Andrew concludes, “The long patent life of EVVA 4KS to 2037, combined with the 130 billion possible key combinations and the fact that 4KS keys are virtually impossible to decode by a key machine or cut on any machine without a software licence provided by EVVA, continues to impress our clients, and gave Steve the peace of mind that he has installed the maximum security in a mechanical master key system on nuclear gauges.”


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