Q&A - Dr Jack Henderson
Dr Jack Henderson manages high-temperature applications support in North America for Netzsch. His primary research interests are heat transfer, thermodynamics, instrumentation, thermophysical properties and nuclear fuel. Materials World spoke to him about the nature of his work in the field of testing and analysis.
What is your background and experience?
I have a PhD in Mechanical and Aerospace Engineering from Oklahoma State University. I was Professor of Mechanical Engineering and Applied Mechanics at the University of Rhode Island, and later Professor of Mechanical Engineering and Head of the Thermophysical Properties Research Laboratory at Purdue University. I then joined Netzsch as Head of its High-Temperature Applications Research Laboratory in Germany. Upon returning to the USA, I held the position of Applications Specialist and am now responsible for nuclear applications support worldwide. In this role, I run a small Netzsch laboratory in Colorado solely for nuclear-related applications. My primary research interests are ceramics and nuclear fuel processing.
What are Netzsch’s main areas of focus?
Netzsch manufactures thermal analysis and thermophysical properties instrumentation that can be used for applications ranging from foods, pharmaceuticals and polymers to high-temperature ceramics, metals and of course nuclear materials. We also operate testing laboratories at several locations around the world, including the USA, Germany and China. These laboratories are set up to carry out measurements on all of the materials just mentioned, and serve a clientele that includes private industry, universities and government research laboratories.
What are the most commonly requested tests that you conduct?
Our most popular instruments are simultaneous thermal analysers (simultaneous thermogravimetric analysis and differential scanning calorimetry), which can cover a temperature range of -180°C to 2,400°C and measure mass change and energetic effects. These are followed by our dilatometers, which measure thermal expansion of materials over the temperature range of -260°C to 2,800°C and our laser flash analysers to measure thermal di¬ffusivity and thermal conductivity over the temperature range of -125°C to 2,800°C. Most of our instruments can also be coupled to evolved gas analysers such as mass spectrometers, FTIRs and GC-mass spectrometers. As a result, our testing business pretty much consists of measurements that can be carried out with these instruments. Again, our clientele here is split fairly evenly between private industry, universities and government research laboratories.
How much work do you do in the nuclear industry?
A significant portion of our instrument sales is to the nuclear industry. With the resurgence of nuclear energy, the so-called ‘nuclear renaissance’, our business in this sector has grown quite rapidly. I think the primary reason for this is that we are not just an instrument manufacturer, but also an engineering company, and are willing to modify and tailor our instruments to specific nuclear applications. The demand for instruments modified for hot cell and glovebox operation has risen significantly over the past few years, and we have been able to accommodate these requirements due to our engineering expertise and flexibility.
What is the most common service you’re asked for?
Without a doubt, it is application-specific modifications to our instruments for both glovebox and hot cell operation.
What are the major challenges when working in the nuclear field?
The biggest challenge is modification of the instruments for glovebox and hot cell operation. In the case of hot cell instruments, shielding is a critical factor, as well as ease of handling during both routine operation and maintenance. Glovebox instrumentation is somewhat less challenging to deal with, since it is significantly easier to operate and maintain the instruments in this environment and shielding is typically less of an issue. In all cases, the instruments must be extremely robust and consideration must be given to accessibility of all components that may require service or replacement. These modifications sometimes require hundreds of hours of engineering time. We routinely use a mockup glovebox during the design process to ensure the instruments meet the challenges presented.
What is the latest big development in testing within the area?
There are several. One trend in nuclear research, due to the accident at Fukushima, is the study of fuel and cladding interaction under severe accident conditions. A considerable amount of research is also currently being conducted on new fuel and cladding systems for the so-called Generation IV reactors. In this regard, there has been a significant resurgence of interest in both tristructural-isotropic (TRISO) and metal fuels as well as novel cladding candidates such as SiC. The challenge for Netzsch has been to design and manufacture instruments that are capable of supporting these research efforts.
How have you worked with a client to design a new process that resulted in a new system or method?
We recently worked with one of the national labs in the USA to build an STA system for glovebox operation. The requirements were twin furnaces with a temperature range up to 2,000°C and vacuum capability to 10-4 mbar. All of the internal electronics had to be separated from the measuring unit and placed outside the glovebox for ease of maintenance. In addition, the instrument is connected to a mass spectrometer located outside the glovebox. This means we had to design special heated transfer lines and feed-throughs to eliminate condensation of evolved gas species. This system will be used primarily for oxide fuels work, for example ThO2, UO2, MOX and minor actinide-bearing MOX.
What is the company’s biggest achievement to date and what will be the next challenge to overcome within the nuclear industry?
I would say it is the development of a new glovebox laser flash system to measure thermal diffusivity and thermal conductivity for nuclear fuel research. This project required several months of engineering, but has resulted in a unique system. The next step in this process will be modification of the instrument for hot cell work on irradiated fuels. Irradiated fuels of course pose unique challenges for thermal transport property measurements.
Has the adverse media coverage since the Fukushima incident last year had a noticeable impact on the demand for nuclear-related services?
Actually, yes. We have experienced an increase in demand, due in no small part to the increased interest in fuel and cladding interaction under severe accident conditions. It is difficult to predict how it will impact our long-term business in this area, but my feeling is that the interest in our products and services will continue to grow because nuclear is the only real carbon-free technology that is capable of meeting the world’s growing energy demand on a near-term basis.