Interview with Roger E. Stoller
As a national laboratory, Oak Ridge National Laboratory researches and develops technology that may eventually be utilized by the private sector. What role do standards play in technology transfer?
ORNL is the U.S. Department of Energy's largest science and energy laboratory, with a primary mission to support the Office of Science. However, capitalizing on potential developments in both the basic science and applied technology programs is also a priority.
One recent tech-transfer success in my division is alloy CF8C-Plus, which evolved from an austenitic stainless steel alloy HT-UPS (high temperature, ultrafine-precipitate-strengthened) that was developed by Phil Maziasz and his co-workers at ORNL for advanced nuclear applications in the 1990s. These same researchers developed CF8C-Plus, which was patented for high temperature, non-nuclear applications in 2006. Because of its excellent properties, CF8C-Plus attracted considerable attention. However, it didn't gain commercial momentum until the ASTM alloy designation in A297, Grade HG10MNN, was obtained. Industry acceptance required having property data and testing that met ASTM standards, particularly for the challenging high temperature performance regime that is the target of this alloy. In this regard, having a standard, agreed-upon methodology for measuring mechanical properties and interpreting the results of the tests provided confidence in the new material.
As of early 2009, more than 400 tons of the new alloy had been cast and employed in applications such as the Caterpillar regeneration system, a high temperature component in the exhaust system of heavy-duty diesel engines built by Caterpillar. The CRS system plays a critical role in enabling these engines to meet strict U.S. Environmental Protection Agency requirements for reduced particulate emissions.
With nearly 40 staff members on ASTM committees, how does ORNL both contribute to standards development and use standards?
I am most familiar with work here in the Materials Science and Technology Division where I am employed. About half of the ORNL involvement in ASTM International activities is from this division, which carries out R&D on a broad range of materials issues from low alloy steels to refractory alloys to advanced ceramic composite materials such as silicon-carbide composites. Much of this research involves mechanical testing of one form or another, and agencies such as DOE and the U.S. Nuclear Regulatory Commission have recognized the value of applying consensus standards in the research they fund.
As a result, division staff members participate in standards development activities in committees such as C08 on Refractories, C28 on Advanced Ceramics, E04 on Metallography, E08 on Fatigue and Fracture, E28 on Mechanical Testing and G02 on Wear and Erosion. This includes helping to organize, and participating in, round-robin testing campaigns with international laboratories. Those of us interested in materials issues for the nuclear industry also are involved in Committee E10 on Nuclear Technology and Applications and C26 on Nuclear Fuel Cycle. These standards are applied by division personnel in their own research here at the laboratory.
The other ORNL divisions with significant involvement in ASTM include the Energy and Transportation Science Division and the Environmental Sciences Division. ETSD houses the Building Technologies Research and Integration Center, which focuses on research, development and deployment of energy-efficient building technologies. Division staff are involved in such ASTM committees as C16 on Thermal Insulation, D08 on Roofing and Waterproofing, and E06 on Performance of Buildings. ORNL maintains an extensive environmental monitoring program, and staff from Environmental Sciences participate in Committee E47 on Biological Effects and Environmental Fate as part of that effort.
What is the scope of your position at ORNL?
Do you mean on a good day or a bad day?
Like many mid-career scientists and engineers, I have substantially more administrative responsibilities than when I started working at ORNL almost 26 years ago. As the manager of the fusion materials program, I am responsible for the administration of the relevant ORNL research activities, which are funded by the DOE's Office of Fusion Energy Sciences, as well as the two long-standing irradiation research collaborations we have with our Japanese colleagues at the Japan Atomic Energy Agency and the Japanese universities. The experiments make use of a wide range of specimens to determine the effects of neutron irradiation on the materials' microstructure, mechanical properties, physical properties and chemical compatibility with other materials. The program is highly collaborative, involving several materials scientists at ORNL as well as colleagues at the University of California and the Pacific Northwest National Laboratory.
My own research has evolved over time. As a graduate student and in my early years at ORNL, I carried out a mix of experimental and computational research. The experimental work primarily involved microstructural characterization using transmission electron microscopy and determining radiation-induced changes in hardness and density.
At this point, my direct experimental activities are more limited, involving a number of collaborators who actually make the measurements. I continue to be heavily involved in computational modeling and simulating the effects of radiation on structural materials both on my own as well as with collaborators at ORNL and elsewhere. More recently, I have used the method of molecular dynamics to investigate primary radiation damage in irradiated materials by simulating an event called a displacement cascade. These cascades are essentially a complex series of billiard ball-like elastic collisions in which a high energy particle such as a neutron plays the role of the cue ball and the iron atoms (in the case of steels) respond like a rack of balls that has just been broken. The event is over in about 10 to 20 picoseconds but leaves a residual damage structure that evolves over longer times to produce a number of undesirable property changes. ASTM standards E693, on characterizing neutron exposures, and E521, on the simulation of neutron radiation damage, discuss some of the relevant physics.
I have also developed and applied other models based on the so-called mean-field reaction rate theory that can be used to describe the processes that take place at these longer times and on larger-length scales.
Atomistic displacement cascade modeling helped answer a long-standing question about applying data from fission reactor irradiations to the fusion environment, namely, whether the higher energy fusion neutrons gave rise to significantly different primary damage than the lower energy fission neutrons. Apparently, the cascades are relatively similar. However, one of the relevant results from the mean-field models was that the higher helium production rate from fusion neutrons (again due to their higher energy), could substantially alter the microstructural evolution compared to fission reactor irradiation.
Most recently, I am one of the principal investigators on a new Energy Frontier Research Center [see sidebar, "Energy Frontier Research Centers"] that has been funded here by the DOE Office of Basic Energy Sciences. It will employ a range of advanced computational and experimental methods to elucidate the fundamental behavior of radiation-induced defects in structural materials.
You have been actively involved in the ASTM symposia on the Effects of Radiation on Materials. What is the value of the ASTM symposia and special technical publications programs?
ASTM International symposia, and the special technical publications from them, help support the technical committees in a few ways. They typically bring together a larger group of knowledgeable experts than the committee meetings are able to attract by themselves. When held in conjunction with committee meetings, a symposium provides the opportunity for the committee or committees involved to tap some additional short-term technical resources - and perhaps attract some new members by introducing them to standards development.
The STPs, and now the online Journal of ASTM International, permit committees to develop an archival record of research relevant to a specific technical issue such as a round-robin testing program that leads to a new standard test method. Historically, the STPs have provided a continuous record of R&D in several areas of personal interest. For example, the excellent STP series, Effects of Radiation on Materials, Reactor Dosimetry, Fatigue and Fracture, and Zirconium in the Nuclear Industry, provide an extensive basic library for anyone interested in these topics.
When did you first become involved with ASTM?
I was introduced to ASTM by my graduate thesis adviser, professor Bob Odette, at the University of California in Santa Barbara. My first involvement was presenting a paper at the 11th Symposium on the Effects of Radiation on Materials in Scottsdale, Ariz., in 1982, with the paper being published in ASTM STP 782 later that year.
Through Bob's collaborations with ORNL I got to know people like Nick Packan, who asked me to participate in Subcommittee E10.08 on Procedures for Neutron Radiation Damage Simulation. As a result, I became involved with Committees E10 and C26, co-chairing and chairing a few of the radiation damage symposia. In this capacity I worked with then-E10 staff manager, Kathie Morgan, and Kathy Dernoga from the publications division, who introduced me to the inner workings of the society. Among the unintended consequences was my being asked to serve on the ASTM Committee on Publications for several years and ultimately being invited to serve on the board of directors.
You have long been a proponent of using IT to support standards development. Over the past 15 years, what have you observed about the impact of information technology on ASTM's processes?
My first encounter with what I thought would be ASTM's IT was in 1990, following the radiation effects symposium that I chaired. I called someone on staff to ask about a particular paper and they said, "Let me pull out the card file." I was using a simple computer database at the time and I was amazed that somebody was using a card file. It was not too long after that that I got involved in the ASTM Committee on Publications, and over the years that I was involved with it, I'm glad to say that I saw ASTM make leaps in progress from the card-file age to the electronic publishing age over a period of just a few years.
Of course, electronic publication brings down costs while increasing flexibility in what and how an organization can publish. Separate standards are more easily available, as are compendia of standards for a given industry, and variations on standards such as redlined versions.
The use of IT has also made the development of a new standard more straightforward with templates that members can use that show required sections for each type of standard. Members of Committee E10 have also availed themselves of other online development tools that ASTM has created such as collaborative workspaces and virtual meetings. Just recently, a task group of Subcommittee E10.02 conducted an online meeting with people here at the laboratory and colleagues in Belgium and Japan. Information technology has been a big help in bringing participants on board from around the world, both by enabling their participation in meetings like the one I just mentioned and also in allowing them to vote on electronic ballots in a timely way.
The committees on which you are active have a great number of non-U.S. participants. How are their standards used around the world?
Historically speaking, the commercial nuclear industry developed in the U.S. earlier than elsewhere in the world, and there was naturally some technology transfer outward. As those industries developed in Asia and Europe, they used technologies that came from U.S. companies such as Westinghouse or General Electric at the same time that they were developing their own infrastructure, so it was natural that ASTM standards were used. The nuclear industry is highly international and collaborative by nature, so the nuclear committees still have substantial involvement from our colleagues in Europe and Asia. More than 25 percent of the E10 and C26 committee membership is from outside North America. In the European Union and nations such as Russia, China, Turkey, and some Middle Eastern and Asian nations, ASTM International standards are applied directly or may be adopted or referenced in national standards.
When did you first encounter ASTM standards as an engineering student?
My first substantive contact was during my first year as a graduate student at the University of California in Santa Barbara. I had a laboratory course taught by professor Gene Lucas in which we were required to conduct a variety of mechanical property tests and were given ASTM standards as references. Gene was an excellent teacher, but it was having the ASTM standards such as E8 on tensile testing and E399 on fracture toughness testing on hand during the laboratory sessions that gave me some confidence in the results I was measuring. This was a good way to be introduced to standards as well as a good example of the usefulness of standards. There is almost always more than one way to do any given test or make any one measurement, and having a good description of the preferred method that has been written by knowledgeable professionals is invaluable to both the novice and the experienced researcher.
Since you work with students, do you have any comments on how standards developers might encourage the participation of new generations of stakeholders?
At ORNL, we have many graduate students who come in and work with us on different research programs for an extended part of their Ph.D. research while continuing to interact with the faculty at their parent university. Surprisingly, it is not uncommon for engineering or science students to graduate and go to work for a GE, a Westinghouse or a Southern California Edison without having encountered standards unless a specific faculty member with that interest has educated them about it. Otherwise, they graduate and learn about it on the job. So I think it has been good that, in the last few years, ASTM has been reaching out to university faculty and students to enable awareness of standardization earlier in the education process.
Last January I participated in a program connected to our ASTM committee meetings in Atlanta where we met with some students from the Georgia Institute of Technology. I made a presentation about E10 and C26 to these students to make them aware of what ASTM International and standards are all about. The students then sat in on a session of Subcommittee E10.02. Since undergraduate engineering curricula are already quite full, it is difficult to find opportunities to add something like a specialized standards module. Therefore, I think this sort of outreach is where ASTM has been and can be successful in reaching faculty and students to educate them about the important role of standards.
What would you like to see accomplished during your year as chairman?
One of the main challenges to the organization continues to be gaining recognition in the marketplace that ASTM is in fact an international standards body. This is really an international trade issue. The U.S. standards development infrastructure is very different from that of Asia or Europe. There, standards organizations are national standards bodies, whereas in the U.S., there are a number of voluntary standards organizations, of which ASTM International is one of the best known. Although we continue to increase our international participation, obtaining greater recognition of the fact that an ASTM standard is an international standard remains a primary challenge to the society because of the nature of the system in the country in which we happen to reside.
In terms of mature industry sectors, ASTM is challenged to encourage ongoing sufficient and effective participation from people in those industries. Even in established technologies, developments are occurring all the time and we need to maintain groups of experts in each of our established technical committees who will both keep existing standards current and develop new standards as technology warrants. This is crucial in helping us maintain what is ASTM International's real market advantage, which is high technical competence and timeliness.
Although my tenure and influence as chairman of the board are limited, I hope that I can help make progress on these and other key issues. I'm pleased and honored to have this opportunity. I've enjoyed working with the ASTM International staff and members I've met over my career; it has been a very interesting and enriching part of my professional life.
Roger E. Stoller, Ph.D., is a distinguished research staff member and the program manager for fusion reactor materials in the Materials Science and Technology Division of the Oak Ridge National Laboratory in Oak Ridge, Tenn. He is a co-principal investigator for the ORNL Energy Frontier Research Center on defect physics that was funded in 2009 by the U.S. Department of Energy's Office of Basic Energy Sciences.
Prior to his arrival at ORNL in 1984, Stoller was a research associate and graduate student at the University of California, Santa Barbara, for four years and was employed as a staff engineer at General Electric's Advanced Reactor Systems department in Sunnyvale, Calif. Stoller is currently an adjunct professor of nuclear engineering at the University of Michigan, Ann Arbor. He is the author or co-author of more than 100 publications and reports on the effects of radiation on materials in environments that include light water and fast breeder reactors as well as fusion reactors.
Stoller earned B.S. and M.S. degrees in nuclear engineering from the University of California, Santa Barbara, and the University of Wisconsin, Madison, respectively. In 1987, he earned a Ph.D. in chemical engineering from the University of California, Santa Barbara.
Since 1986, Stoller has been an active and recognized member of ASTM Committee E10 on Nuclear Technology and Applications, contributing to standards development in that committee, holding subcommittee offices and serving as E10 chair from 2002 to 2007. Twice he received the E10 Award of Appreciation, in 1988 and 1990; in 1995, he received the Award of Merit and title of fellow from the committee. He has been actively involved in the success of the ASTM symposia on the Effects of Radiation on Materials, which are sponsored by Committee E10, serving as symposium chairman, co-chairman, presenter and author. He is also a member of ASTM Committee C26 on Nuclear Fuel Cycle.
A member of the ASTM Committee on Publications from 1993 to 2003, Stoller held the positions of vice chairman and chairman. He has served on the ASTM board of directors since 2004, including his year as chairman of the Finance and Audit Committee in 2007.
In addition to ASTM International, Stoller is a member of the American Nuclear Society, where he is a former chairman of the Fusion Energy Division, ASM International and the Materials Research Society. He was named a fellow of ASM International in 2007 and a fellow of the American Nuclear Society in 2009.
All photographs: Curtis Boles, ORNL.