Q1: How did you get into nuclear engineering?

A1: Hussein Khalil was born in Egypt and moved to the United States during middle school. His interest in math and science coupled with a desire to contribute to the wellbeing of society in the future led him to pursue nuclear engineering at Kansas State University. Khalil received his PhD at MIT where he focused on Reactor Physics to describe neutron distribution in light water reactors and predict detailed distribution of the reaction rates in the assemblies and pins in the reactor core. In order to verify the predictions, Khalil completed post-irradiation examinations of fuel pins and used instruments to measure the temperature and other readings to determine the neutron flux.

Q2: What did you learn about what’s happening inside of these cores?

A2: Hussein Khalil used instrumentation and sensors to get at physical parameters in the core and used models and analysis to interpret those parameters. These analyses are helpful for designing better reactor systems in terms of performance and safety. Reducing computational uncertainty allows a design closer to the design of the materials, which maximizes the amount of energy you can extract from a reactor. The modeling tools have multiphysics capabilities and are also used to describe the heat transfer, fluid flow, structural mechanics, and chemical reaction effects in the reactor.

Q3: Tell us about some of your early projects with new types of reactors.

A3: Hussein Khalil joined Argonne National Labs at a time in which the Integral Fast Reactor Program was ongoing. The interest in fast neutron reactors is focused on improvements to the nuclear fuel cycle that could be made, such as making more efficient use of uranium resources and recycling of fuel that is discharged. Approximately 95% of the uranium still remains in a light water reactor fuel assembly, with about 1% plutonium, which can be extracted and used in a fast reactor. The binding energy of the nuclei in a nucleus goes through a minimum of very heavy elements or extremely light elements, and goes through a maximum in between. Energy can be generated by splitting very heavy elements, known as fission, or by combining very light elements, known as fusion.

Q4: Tell me about higher processing.

A4: Hussein Khalil has worked with higher processing, which is a type of electrochemical processing. In this process, used fuel is the anode of the system and the cathode is the heavy elements that are transported through the electrolyte by electric current. These heavy elements get deposited at the cathode and are separated from the fission products which stay in the electrolyte. By changing the voltage, you can control which elements you filter out.

Q5: What did your work with the integral fast reactor lead to?

A5: In 2000, Hussein Khalil was involved in the Gen 4 initiative, which was an international effort focused on determining what the future generation of nuclear reactors would look like. Multiple reactor systems were chosen at the time to be deployed, but were not brand new designs. Many of these fast reactor designs already existed at Argonne National Lab. Argonne’s reactor resume includes heavy water reactors, which uses deuterium oxide instead of light water as the coolant and a boiling water reactor, which was the first demonstration that a power plant could be operated using water that’s boiling in the core of a reactor. The Gen 4 program recommended pursuing three different types of fast reactors: gas-cooled, lead-cooled, and sodium-cooled. Other recommendations were high temperature reactors cooled with helium gas and molten salt reactors.

Q6: What comes out of the Gen 4 international forum?

A7: Hussein Khalil participated in the Gen 4 international forum which developed a technology roadmap for developing the new generation of nuclear reactor systems. This roadmap showed what research and development is needed to show the systems are viable, operable, and reliable. The last phase of this roadmap was envisioned as a demonstration phase, in which a prototype of the system would be built. Different countries are pursuing theses systems to different degrees, and not all countries are looking at all of the technologies.

Q7: Which method do you think would be better to guarantee a successful outcome of exploring these different technologies put forward in the Gen 4 initiative?

A7: Hussein Khalil sees intellectual property and commercial interest get in the way of a truly open international collaborative setting regarding development of Gen 4 reactors. The competitive aspect of technology development became more difficult as the systems mature, and the commercial involvement and investment money also increases as it matures. The economics of nuclear reactor construction and operation affects investment decisions, as well as factors such as safety, security, and proliferation risks. Economics can be improved by simplicity of design and cost of building materials, but it is difficult to calculate the costs and benefits of replicating and scaling a reactor design.

Q8: It is important to have diversity in the systems that are being commercially pursued because the more we can see built in the real world, the better sense we can have about how the economics are going to play out.

A8: Hussein Khalil supports a diverse approach in system development to identify and recognize different strengths in different applications. High temperature reactors could potentially deliver heat at 1000 degrees Fahrenheit, which could be used to split water to produce Hydrogen through thermochemical cycles. Thorium fuel reactors could utilize an additional source to uranium for nuclear power generation. Khalil is part of the Gateway for Acceleration Innovation in Nuclear (GAIN) initiative which focuses on forming public-private partnerships where companies have access to resources and capabilities at nuclear labs.

Q9: Do you find that industry is aware of the nuclear lab capabilities or are still learning about it?

A9: Hussin Khalil and the leadership team at Gateway for Acceleration Innovation in Nuclear (GAIN) is trying to create a more streamlined process for industry to access the nuclear labs. Khalil hopes for a brand new era of nuclear technology in which the industry can take advantage of advancements in other fields, such as materials, computation, and manufacturing. The Nuclear Regulatory Commission (NRC) is interested in a more flexible approach to admit new technologies and innovations into the industry.