Mark’s involvement with ANSTO (0:09)
0:09-5:01 (Mark describes his involvement with ANSTO and how he first became interested in the nuclear industry.)

Q. Where are you right now?
A. (0:20) Mark Ho works at the Australian Nuclear Science and Technology Organization (ANSTO) as a thermohydraulic specialist. ANSTO has a 20 megawatt research reactor which is used in the creation of radio medical isotopes and for neutron gathering experiments. In addition to his work at ANSTO, Mark is also a subject matter expert for the Australian Nuclear Association (ANA).

Mark first joined ANSTO as an undergraduate intern. He was attracted to their highly technical work and the water tunnel facility used for fluid experiments. He did his undergraduate and Masters of Research at ANSTO and was eventually offered a job there.

Mark has always been interested in mechanical engineering. The highly technical aspect of the nuclear industry is what captured Mark’s interest. Mark’s specialty is computational fluid dynamics, which is incredibly demanding and requires overlapping different disciplines. The nuclear sector enables Mark to study both experimental fluid mechanics and computer programming.

Australia’s energy history (5:02)
5:02-10:20 (Mark describes the history of ANSTO and why the nuclear industry did not develop in Australia.)

Q. How long has ANSTO been around for?
A. (5:08) ANSTO was established by Parliament in 1987. Prior to this, the organization was known as the Australian Atomic Energy Commission, which was established about 50 years ago. Eisenhower’s Atoms for Peace somewhat influenced its creation. At the time, Australia knew of their uranium reserves, but were unsure how much uranium was around the world. The government therefore invested in Australian nuclear competency to contribute to the global effort towards the peaceful use of nuclear power.

Australia did not, however, develop commercial nuclear power plants at this time primarily for an economic reason. Australia has a large coal reserve and chose to develop their coal industry. It therefore did not make economic sense to also develop their nuclear industry. A nuclear power plant was planned to be built at Jervis Bay, but the high cost ended the project.

Clean air is an argument against the use of coal in Australia. A coal plant known as Hazelwood was recently shut down in the Latrobe Valley in Victoria. While this did increase air quality, the loss in power decreased the grid by 2 gigawatts, causing power prices to increase. Mark states that Australia will need to go through an energy transition soon. This is because the entire country currently only has a 50 gigawatt capacity. South Australia is a less populous state and have transitioned towards renewable energy sources backed by gas. However, the state is also interconnected to Victoria and uses Victoria’s coal power to backup their own energy needs. About two years, high winds blew over many power lines creating a major power disruption and blackouts. This points to the need for Australia to develop an additional cleaner power source to complement renewables.

Australian public attitudes towards nuclear (10:21)
10:21-13:51 (Mark explains how the Australian public is evenly split in their views towards nuclear. He discusses how increasing education can open the nuclear discussion.)

Q. Did any of your friends or family give you funny looks when you started developing this niche expertise?
A. (10:28) Mark’s family and friends hear too much about nuclear power to not like it. The Australian National University in Canberra surveyed public attitudes towards science and technology and included a question about nuclear power. They found an even split in support for nuclear while gas fracking was viewed negatively in 70 percent of responses. Mark has found that many people support renewables but are unaware that they must be backed up by another form of power generation. Once they are informed that renewables are currently backed by gas, they become more open to the nuclear conversation. Mark believes that people are tribal and will automatically associate themselves in favor of renewables when they say they want to decarbonize. There are still many debates and arguments about how to decarbonize, but Mark believes it is important for nuclear to remain in the discussion.

Simulating reactor bubbles (13:52)
13:52-21:44 (Mark discusses his experience creating computer code to simulate bubble creation in reactors and why this is important for the industry.)

Q. What became your technical area of expertise?
(13:59) Mark is more of an experimentalist, focusing his Masters degree in fluid flow induced vibration for a parallel plate research reactor fuel assembly. His PhD explored code development for interface tracking for two face flow. Mark is now shifting towards advanced reactors and understanding reactor history to explain why pressurized water reactors dominate the industry.

A deep understanding of boiling dynamics and boiling mechanics are needed when designing and operating pressurized water reactors. Understanding bubble creation is critical to understanding heat and mass transfer. In the past, a lack of computation power meant simulating this interface was simplified. This creates a nonideal representation, creating room for error and divergence between the optimal and numerical solution. Mark worked to create a much more accurate plot of where the actual interface is to create a better representation of reality. Simulation results are used to construct better mathematical formulas for use in systems such as RELAP code, which is a one dimensional thermohydraulics code for analyzing reactor safety in transient events.

The shape of bubbles are determined by the balance of forces between the internal and external pressure and the interplay with the surface tension effect. Pressurized water reactor bubbles are smaller and behave differently from normal, everyday bubbles due to the difference in atmosphere inside the reactor.

Salt versus water reactors (21:45)
21:45-30:00 (Mark describes how his interests led him to explore the benefits of water-based reactors. He also explains the need to diversify the reactor technology used in the future.)

Q. When did you become involved with the Australian Nuclear Association?
A. (21:55) Mark became seriously interested in reactors during his PhD. This led him to explore such topics as fusion, advanced reactors and salt reactors. His interest in pressurized water reactors led him to explore why water is used, which he learned was because of water’s ability to cool and shield radiation. Additionally, water has a high heat carrying capacity. For instance, a salt reactor may only have half the heat carrying capacity as water for the same volume.

Mark believes that although we should be enthusiastic about advanced reactors, the existing fleet of water-based reactors still deserve recognition. There are, however, some advantages of molten salt reactors over water-based reactors. Australia is part of the Gen 4 Forum and will be focusing on molten salt and high temperature reactors. This is because they have higher operational temperatures, enabling wider spread decarbonization. Mark believes the industry should have a wide spread of technology, developing both water-based small modular reactors and salt-based reactors.

China’s nuclear industry (30:01)
30:01-37:14 (Mark explains how China is investing in salt reactors and the first HTGR.)

Q. Is creating an economic comparison a fair way to decide reactor designs?
A. (30:08) We don’t know what we don’t know, and discovering this requires investment. The Chinese government is exploring this by investing in molten salt reactors. They are also focused on deploying many pressurized water reactors. China has doubled their nuclear capacity in 5 years and are estimated to have 130 gigawatts of capacity in 2030 and 500 to 540 gigawatts of capacity by 2050. The Chinese are commissioning the first high temperature gas reactor (HTGR) for the HTR-PM, which is a small modular reactor design. This reactor will increase the temperature that a reactor operates at, producing more power. The output power for this plant with two reactor pressure vessels (RPVs) for one steam generator will be 200 megawatts. The following iteration will have 6 RPVs for one turbine, producing 600 megawatts. These reactors will be placed inland and air cooled as opposed to pressurized water reactors which must be located near the sea for water-based cooling.

Overturning Australia’s nuclear ban (37:15)
37:15-41:42 (Mark discusses the efforts in place to remove the current nuclear ban in Australia.)

Q. How will you get rid of the national nuclear ban?
A. (5:49) There are currently two inquiries into overturning the ban. One is in the senate to explore the possibility of using nuclear power in the future. While the current government holds the position that there will be no change in the nuclear law, they are beginning to look into the benefits of nuclear power. The other inquiry is at state level, where New South Wales is looking into removing the nuclear ban.

There are two major federal bans on nuclear power: the Environmental Protection and Biodiversity Conservation Act (EPBCA), which bans nuclear construction, and the Australian Radiation Protection and Nuclear Safety (ARPANS) Act, which bans nuclear licensing. These acts were used to appease the Green Party about 20 years ago as a compromise for building a new research reactor for the production of medical isotopes. Lifting the nuclear ban was considered about 10 years ago after a report advised Australia to build nuclear power plants. The government at the time was not reelected, and so lifting the ban was not pursued.

Nuclear is politicized in Australia. Mark sees this as unfortunate, because he just wants people to see nuclear for what it does, which is to produce low carbon electricity. This is easily seen when comparing France and Germany. Despite Germany’s large investment in renewables, France has a lower carbon footprint than Germany.

Public outreach (41:43)
41:43-45:45 ()

Q. Why do people spend time attacking nuclear before coal when the health issues of coal are well known?
A. (10:17) Mark believes people who are against nuclear power have associated it with nuclear weapons. The Australian Nuclear Association (ANA) is a collection of nuclear professionals that speak about nuclear technology within the industry. Engaging wider audiences through plain text communication requires more resources than the ANA has. The Minerals Council of Australia supports nuclear and has the resources to engage the public in nuclear education. However, the Council represents different mining industries, including coal.

Mark’s future for nuclear (45:46)
45:46-48:00 (Mark describes his current work relating to advanced reactors. He also explains his optimistic view of Australia’s nuclear industry moving forwards.)

Q. You spend your time looking at the Gen 4 technology now?
A. (14:19) Mark’s primary job is focused on the safety of the OPAL research reactor. He would like to spend more time researching advanced reactors, but advises a few PhD students that work on research. Mark also looks at overseas nuclear reactor technologies to keep up to speed with development in other countries.

Looking towards the future, Mark would like to see the Australian nuclear ban overturned. He is optimistic, and thinks the conversation in Australia is currently moving in the right direction and predicts the nuclear industry will recover.