1 - Early International Nuclear Studies

Bret Kugelmass: Tell me about your early interest in nuclear.

Kathryn McCarthy: Kathryn McCarthy grew up around the San Francisco Bay area since her father worked at Livermore Lab, one of the weapons labs that happens nuclear material. This exposed her early on to many engineers and physicists. In high school, McCarthy planned to pursue music, but a passionate high school physics teacher inspired her to study nuclear engineering at the University of Arizona. One of her professors was Norman Hilberry who was the axman in the first Chicago Pile Experiment. This was one of the original critical experiments which proved that fission could be controlled. Hilberry mentored McCarthy during her time in Arizona and she eventually left to pursue her graduate degree in nuclear engineering at UCLA. At the time, there wasn’t much R&D in the fission world, so McCarthy’s graduate work was related to fusion, specifically liquid metal magnetohydrodynamics. She finished graduate school and worked abroad for six months in West Germany at the Kernforschungszentrum, which later became Karlsruhe Institute of Technology. McCarthy and her husband then went to the Soviet Union in 1989 and 1990 working on liquid metal magnetohydrodynamics.

2 - Path to Idaho National Laboratory

Bret Kugelmass: Where you in the Soviet Union during the collapse?

Kathryn McCarthy: In August 1989, Kathryn McCarthy and her husband were in Leningrad having dinner with some friends who worked at the French consulate. Her friends had heard that wall had come down in Germany, but didn’t know if it was true. Soviet news downplayed the event. McCarthy’s assignment ended in September 1990, just before the coup in December. Upon returning to the U.S., she took a position at the Idaho National Laboratory (INL) where she spent 25 years, starting out in the fusion safety program. A model was developed to look at safety analysis of the fusion machine to understand pressure drops and heat profiles, which fed into McCarthy’s research. She was also responsible for volatilization of materials experiments. When tokamaks are exposed to high heat, there may be an air ingress and some of the material can oxidize, creating dust or particulates. Temperatures in tokamaks are higher than the temperature of the sun. Liquid metal is a coolant, absorbs neutrons, and can take very high heat flux. McCarthy became a manager responsible for the fusion work and some of the fission work, eventually focusing on the advanced fuel cycle initiative. She was on the Department of Energy (DOE) Fusion Energy Sciences Advisory Committee (FESAC), allowing her to stay engaged in the fusion community.

3 - End of the Nuclear Fuel Cycle

Bret Kugelmass: At which point did you switch to the fuel cycle?

Kathryn McCarthy: Kathryn McCarthy switched to focus on the fuel cycle when a new contractor, Battelle, came into Idaho National Laboratory (INL). They wanted her to take over systems analysis for the advanced fuel cycle initiative. The focus at the time was on the back end of the fuel cycle, looking at disposal or recycling. There were other disposal options that came up other than Yucca Mountain, but the question was what would actually go into disposal. Frane recycles the plutonium, but the rest of it gets disposed of, which is where some of the high heat and radiotoxic material. Options for the end of the fuel cycle depend on which constraints are used, such as a constraint for never having pure plutonium separated in any streams. McCarthy looked at the whole system, including number and size of tanks, supply chain, and transportation. There are scientific solutions to spent fuel recycling, but the urgency argument is hard to make since there is a lot of uranium. Another argument is that humans should be good stewards of all resources for all generations to come, which is true, but loses the urgency. Because of process losses, there must always be some sort of long-term repository, but the size and number of these repositories can be minimized. Nuclear energy, science, and technology was always the core of INL.

4 - Canadian Nuclear Laboratories

Bret Kugelmass: What was the opportunity that resonated with you to join Canadian Nuclear Laboratories?

Kathryn McCarthy: Kathryn McCarthy took an opportunity with Canadian Nuclear Laboratories (CNL), which used to be a GOGO (government-owned, government-operated) entity called Atomic Energy Canada Limited (AECL). It was changed to a GOCO (government-owned, contractor-operated) so contractors could bring in more of a business-like sense in making decisions based on priorities and increasing the non-government work. CNL is a sister lab to Idaho National Laboratory (INL). McCarthy participated in rebuilding CNL, which had not gotten investments made over many years. When it was restructured to GOCO, the government provided R&D funding and, over the ten year contract, $1.2 billion dollars for infrastructure. One of the new buildings will be an advanced nuclear materials research center and some of the existing facilities are being revitalized. The Canadian government decided they were not going to get back into the business of designing reactors; AECL designed the CANDU reactor. The design for NuScale started as a LDRD (laboratory directed R&D) project that was done in conjunction with Oregon State University. There must be a marriage between the National Labs and the industry. The labs have great ideas, but sometimes practical implementation takes a discussion. Hydrogen is an energy carrier. Right now, the majority of hydrogen is produced from methane. There are better uses for methane and it produces greenhouse gases in hydrogen production.

5 - Small Modular Reactors in Canada

Bret Kugelmass: Would a hydrocarbon be broken up to produce hydrogen?

Kathryn McCarthy: Canadian Nuclear Laboratories (CNL) worked with Jacobs on a project in Toronto to look at converting the light rail to either electric or hydrogen, specifically related to safety. Under certain circumstances, there can be hydrogen explosions. At Fukushima, there were hydrogen explosions because there was an accumulation of hydrogen exposed to oxygen. Moving to hydrogen powered cars requireds a distribution system. Right now, CNL is looking at heavy transport such as trucks and trains, especially in the far northern regions that don’t have current gas infrastructure and investments must be made. Canada is an attractive place for small modular reactor (SMR) vendors is that there is a market of remote communities and mines which currently rely on diesel, currently estimated at 200-300 communities. Mines would be interested in an SMR on the order of 10-30 megawatts, but it must be able to compete with the cost of diesel, which is expensive. In 2018, CNL put out a process for applications to a site, which was partially based on a request for expressions of interest that had been put out in 2017. Canada has potential market opportunities before export. The Canadian regulator’s framework is technology-neutral, meaning it is very outcome-oriented compared to the process-oriented U.S. Nuclear Regulatory Commission (NRC).

6 - Biological Radiation Applications

Bret Kugelmass: Is there an alternative mechanism in Canada in which the national lab system could have a parallel license project for microreactors that might go on lab land?

Kathryn McCarthy: Canadian Nuclear Laboratories (CNL) is regulated by the Canadian regulator, as opposed to the U.S. National Labs. CNL has a goal to demonstrate a small modular reactor (SMR) by 2026. They worked backwards from that date and built in minimum timelines for the regulator. This requires a design that is close to ready to go to meet the 2026 goal, but the goal is still feasible. CNL received four applications to site for SMR’s and there are one to three additional applicants that plan to apply. CNL historically has done work on the biological effects of radiation and a large portion of the worldwide database for effects of low-level radiation was developed at CNL. This database shows that the linear no-threshold theory shouldn’t be used, but it’s difficult to undo something that has been in place for a long time. People look at medical radiation as different than nuclear energy radiation. Radiation is used to treat tumors, but there is a lot of collateral damage with treatment from outside the body. With alpha therapy, compounds could be attracted to the tumor and target the tumor specifically. The nuclear industry needs to do a better job with talking about things that get used in nuclear treatments and diagnostics. There are everyday uses for radiation that people don’t realize. Nuclear is essential to climate change mitigation, having clean air, and having affordable energy broadly available.