Online Elemental Analysis pt 2

The conversation with Stephan Nel continues in this episode.  Nuclear Instruments from Real-Time Instruments are available in two configurations and contain different isotopes according to the application.  Stephan addresses the myth on how they operate and what happens to spent isotopes once they reach their half-life. 

Transcript

[00:00:09.650] - Sean 
This is a Yokogawa, Australia and New Zealand podcast. 

 [00:00:12.950] - Sean 
Welcome back to a new episode of Yokogawa Debunks. Conversations with industry experts to demystify misconceptions and myths we hear in the process instruments and process automation space. 

 [00:00:25.550] - Sean 
I'm your host, Sean Cahill and thank you again for joining us. Now, today we'd like to continue our chat with Stephan Nel from Real Time Instruments or RTI Australia. Hi, Stephan, and thanks again for joining us once more. 

 [00:00:41.690] - Stephan 
Thank you very much Sean, pleased to be back and hopefully you got quite a few likes on the previous session and looking forward to this one. 

 [00:00:50.930] - Sean 
Thank you, Stephan. It certainly led to many questions coming up, which hopefully we're going to be able to answer today during this session. So Stephan, now I believe that there are two main configurations of these nucleonic devices. I'm just wondering if you could give us a bit of an insight into the two technologies. 

 [00:01:08.030] - Stephan 
Yeah, sure, Sean. Probably the most common utilization of radioactive isotope technology within any operating or processing plant is the measurement of density and even level of materials within Hoppers and chutes. And that's where we would utilize the Cobalt 60 or Caesium 137 isotopes. And essentially in a level type set-up, how it works is that you got a nuclear isotope mounted in a lead-encased enclosure on the one side with the detector on the other side, and as a material, the level rises within the Hopper or tank. 

 [00:01:50.570] - Stephan 
It then blocks off the radiation and it's detected by the detector, and then will give you an indication of level within that Hopper or vessel. 

 The second is the use of Caesium 137 or cobalt 60 in density measurement. And as I mentioned in the first episode, it essentially works on the principle of the denser the material becomes the less and less radioactive energy is transmitted through the pipe and is detected by the detector on the other side of the vessel or pipe, and it then computes to then display the density of the material. 

 [00:02:29.510] - Stephan 
So less radiation means a higher density of material in the pipe or vessel. The other use of radionuclides is for neutron activation or, as we mentioned before, prompt gamma neutron activation analysis. And this measures the elemental composition of material on conveyor belts as it's being conveyed from some safe, for argument sake, a crusher to a stockpile. Now, this works on the principle of a neutron generator being either Californium 252, a neutron accelerator tube, which is an electrical device or americium-beryllium isotopes, and it emits a neutron from the source. 

 [00:03:16.610] - Stephan 
Now let's look at an individual neutron, but we have to consider that this is actually neutron flux or a cloud that's transmitted into the material. When we spoke about safety in the first episode, what we have to remember is the fact that it's in the best interest of these OEMs that supply this type of technology to maintain that neutron flux or keep the neutron flux within the boundaries of the Analyzer and kind of limit the amount of neutrons that are able to escape or get emitted outside, and in doing so, the more neutrons you have inside the Analyzer, the higher the probability of that neutron then colliding or interacting with the atom of a specific nucleus and the activation and occurring. 

 [00:04:05.090] - Stephan 
So that's also a function of the gamma production efficiency within the Analyzer. Now, as this neutron collides or interacts with the atom, it imparts the energy, the atom returns to its natural state by emitting a gamma, that gamma is at a specific energy level and is deemed the specific to that element. And as I mentioned before, through spectral analysis, you can then determine what that element is by just looking at the peaks of those energy levels. And this is very useful, determining elemental composition of materials where you want to control specific parameters into some pyrometallurgical processes, also to build stockpiles to a specific quality that's required for the processing of that material. 

 [00:04:57.650] - Stephan 
The use of this technology is of particular interest to companies that do cement production where they want to control the lime saturation factor and the iron and silicon modulus. These are just some of the parameters that they would like to control in terms of producing a very high quality clinker that ultimately leads to the production of cement. 

 In coal mining, there is a term called calorific value and ash. These are of particular interest when you look at some boiler requirements where they can only burn a specific type of coal that's within a range of some specific calorific value. 

 [00:05:38.690] - Stephan 
This is particularly important when you have to start looking at improving boiler efficiency, which is ultimately amount of coal input for megawatt-hour produced. 

 In steel production, it's very similar to coal where they produce a particle sinter. The basicity control or calcium-silica ratio is of high importance to them in order to produce a sinter that can be used in a process further downstream in order to produce iron. There are various applications for this technology and the fact that it's a non-intrusive type technology does make logical sense to reduce the capital or capital spend over time in terms of maintenance requirements on some of this instrumentation, and that's what makes it attractive for a lot of industries. 

 [00:06:27.830] - Stephan 
But again, the myth regarding radiation safety is a determining factor in whether this technology gets adopted and applied or not. The availability of data on a real-time basis is vitally important for operators to start looking at improving operational efficiency and making some proactive decisions in regards to control of downstream processes. And this is where nuclear equipment becomes invaluable in making up the arsenal of what these operators have currently to provide some real value to their shareholders and stakeholders within this business. 

 We've also seen a sharp acceptance of the density type measurement technology within Dredging plants. 

Normally, the Dredging company would be paid based on tonnage Dredged combining the density system with some type of a mass flow or velocity measurement device can provide you data in terms of the dry tonnage that's been dredged or conveyed. And ultimately, that's what the companies would be paid on, and also in some of these mineral processing plants and even coal handling processing plants. They are pumping a lot of the tailings or what they would call the rejects onto tailings dams and to maintain a specific density. 

 [00:07:59.210] - Stephan 
They have to control that by the addition of water to prevent pipes from blocking up, and also in terms of being paid and looking at how much of the material is actually being rejected to do metallurgical accounting within the process. Those are probably the two major applications of the technology within these various industries. I'm sure that there is probably much more of those, but these are the two major ones. We could obviously assist our customers in determining whether this technology will be suitable for their specific application. 

 [00:08:36.050] - Stephan 
All they need to do is just get in contact with us and we can assist them and determine the feasibility of such a project going ahead. 

 At this point, I think it should be quite interesting to mention the fact that with the use of all these isotopes, the Am-Be, Californium, Cobalt, Caesium, and various others, there is a term that's used it's called the half-life of the isotope. In determining a specific application or the use of a specific type of isotope within an application is dependent on some external factors, such as the penetration of the outside vessel walls or the thickness of material on a conveyor belt and that kind of thing. 

 [00:09:17.930] - Stephan 
So there are specifics that need to be considered. And I would just like to mention that Californium 252 that's used in online analysis has got a half-life of approximately 2.65 years. So essentially, it means that if you start off with a specific activity and there's what they call automatic source decay that occurs as these disintegrations occur within the isotope itself. So after 2.65 years, it will reach half its actual initial capacity or radiation level. With this type of isotope, you can actually top it up. 

 [00:09:54.470] - Stephan 
Cobalt 60 is 5.3 years. After it reached at 5.3 years. If it cannot penetrate the vessel or pipe wall anymore, it gets discarded. Similar to Caesium 137, it's got a 30-year half-life. Am-be has got a 432-year half-life, so it lasts extremely long. Now, as I mentioned, Cobalt 60 is 5.3 years, It's a high energy, but it does decay much quicker because of the disintegration happening within the isotope itself. So ultimately, the selection of the isotope technology to be used is application dependent, and this is why we require to do this feasibility in order to determine the best solution. 

 [00:10:43.670] - Sean 
Look, thanks, Stephan. It's a really detailed and informative response that you’ve given there and it's clear there's a whole range of options to select from. And RTI is going to require application details from an end-user to make an informed decision on which Analyzer Type and also the isotope to use. Now, when you provided your description there, you mentioned something about half-life and something you hear a lot about nucleonic devices. And you mentioned earlier how Cobalt 60 presents a challenge once it's reached its half-life, what do you actually do with it when it's reached that point and how you dispose of radioactive resources? 

 [00:11:19.670] - Sean 
I've seen myths out there that once they reach this lifespan, that these radioactive resources then are buried in the middle of a desert, for example, I wonder if you could address those sort of misconceptions for me. 

 [00:11:33.390] - Stephan 
The misconceptions about the fact that some of this stuff, these used isotopes get stored undersea and within mine shafts, and there is some truth to it. And again, the management and disposal of these isotopes are very strongly regulated by some organizations globally. 

 We have to understand that once it reached a specific half-life, which becomes unusable, it has to be disposed of. And there are various companies that actually manage the disposal of these isotopes globally. And in Australia, we've got several of those that do manage this, and we have to understand also, in addition to that that some of these isotopes, although it's reached a non-usable activity for a specific application, it can be reused in another application where perhaps the pipe is not as big as the previous application, so they can be reused and reutilized within some of these operations. 

 [00:12:33.930] - Stephan 
It is by law a requirement that the country of manufacture and the actual company of manufacture at some point have to take these isotopes back. We then assist our customers in terms of documentation requirements in order to dispose of these isotopes. If it cannot be utilized in a different application, it can be sent back to the country of origin where it has to be disposed of in a regulated manner. Now, as I mentioned before, Am-Be has got a 432 half-life, so you can understand the management of that isotope becomes extremely arduous. 

 [00:13:15.450] - Stephan 
Hence the reluctance to kind of incorporate that kind of isotope within the instrumentation or the equipment supplied by these OEMs are very high, and they would prefer not to. The advantage of using Californiun 252 at 2.65 years Half-life, obviously becomes evident then that it can be topped up after 2.65 years by just adding an additional isotope to it. And after a period of approximately ten years, all those isotopes that have now actually reached half the capacity or life are then disposed of in countries that manufacture those, and probably the biggest suppliers of Californium 252 is Russia and the US. 

 [00:14:10.350] - Stephan 
Caesium 137 isotopes at 30 years half life. I've seen them being utilized again in different applications, and they can be purchased as second-hand isotopes. But there is also a definitive period that you can use these isotopes for, that is defined for each isotope individually, after which there is a possibility it might leak out of the capsule, which then creates a hazard for both site people and the public in general. But I want to kind of emphasize the point that the management and storage and disposal of these isotopes are very strongly regulated and the OEMs will definitely assist the customer in the disposal process of these isotopes. 

 [00:14:57.390] - Sean 
So I think it's very clear from that Stephan, I mean that the end-users are not left to their own devices on this. They're not left wondering what they need to do when something reaches its half-life. They're not left wondering how the disposal is. I mean, it's a full closed-loop system whereby customers can address the needs of expired isotopes and also replace and extend the life of their plant. 

 Now, look, it's been a great chat. Unfortunately, we've once again come to the end of this particular episode, and we'd love to leave an open invitation for you to come back again for future episodes of Yokogawa debunks. 

 [00:15:33.090] - Stephan 
Thank you very much Sean, I'm looking forward to that. I would strongly recommend that customers do reach out to us if they do see a need for such technology, but are still concerned about the use of radioactive isotopes on the various sites. And I think this initiative in terms of debunking some of these myths around the use of technology on various sites are very important. and again, Congratulations on this initiative 

 [00:16:03.330] - Sean
and debunking many of the myths that are out there one at a time. So to you, our audience, thank you very much for listening today, and thank you again for Stephan. And if you've got any questions, please reach out to ourselves at debunks@yokogawa.com or direct to Stephan at Stephan.Nel@rtiaustralia.com 

 [00:16:20.550] - Sean 
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Until next time. Yokogawa Debunks.