What’s the go about nuclear?

If you grew up in the 90’s/2000’s like me, it's likely your knowledge on nuclear is grounded in pop culture largely from a little cartoon called The Simpsons. Portrayals of green oozing radioactive waste and three eyed fish led us, as Australians who are not versed in nuclear in our everyday life, to believe that nuclear was poorly managed, unsafe and bad for the environment. This has led to fear, largely due to the lack of exposure and discussion on nuclear technologies. Let’s wind forward to 2024 and nuclear is a hot topic of discussion across Australia. From national security through to green climate policy, those of us in the Australian nuclear industry are so proud to share in the peaceful uses of nuclear power, propulsion and beyond. The wider world is going nuclear, so as members of the Australian Army, it is important for us to understand a little bit more about nuclear.

What is nuclear power and how prevalent is it?

Both civilian and military developments in nuclear power generation stem back to predominately the United States in the 1950’s. The main player in the nuclear power game at the time was Admiral Hyman Rickover who developed the pressurised water reactor (PWR) for naval propulsion with the first nuclear powered submarine, USS Nautilus, being launched in 1954. This development led to the first commercial PWR by the US Atomic Energy Commission in 1957 through the Shippingport demonstration PWR in Pennsylvania. Globally there are 439 operable reactors across the world producing around 10% of global electricity generation[1]. There are around 60 reactors currently under construction and plans for around 100 more reactors into the future. At the United Nations Climate Conference (COP 28) in 2023, 25 countries pledged to triple their nuclear output by 2050 to reduce carbon emissions[2]. In addition, there has been an increase in new to nuclear nations starting their journeys to build civilian nuclear power programs. Of note, some of these countries are our near neighbours, Indonesia, Philippines, and Singapore for example. But Australia is already a nuclear nation and has safely and securely operated research reactors in Lucas Heights, Sydney, for over 70 years. The Australian Nuclear Science and Technology Organisation (or ANSTO) is the home of Australia’s nuclear knowledge and produces a large amount of nuclear medicines used by pretty much every Australian in their lifetime[3]. With the announcement of nuclear-powered submarines through AUKUS, this Australian nuclear workforce and knowledge is growing, which is exciting.

So how does a nuclear reactor power work?

Much like a coal fired power plant, the main aim of a nuclear power plant is to generate heat to create steam which spins a turbine to create electricity. The difference is that instead of burning coal, there is a nuclear reaction which creates thermal neutrons which in turn create the heat. There are many different reactor designs which determine how the neutrons are generated. This will vary fuel types, moderators and coolants used to control the reaction for the desired energy output. The image below is of a PWR, as it is the most common reactor globally[4]. Other reactor designs include boiling water reactors (BWR), pressurised heavy water reactor (PHWR), advanced gas-cooled reactor (AGR), light water graphite-cooled reactor (LWGR), and fast neutron reactors (FNR). No matter the reactor type, this reaction is housed in the containment structure and largely the electricity generation part is the same or similar. Where this differs is in some of the advanced reactor designs, like the TerraPower natrium reactor which is a sodium fast design with storage capabilities. I don’t have the word count to delve into that type of reactor (it is a cool design), you can find out more on the TerraPower site[5].

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What about waste?

Australia already managed waste from nuclear facilities. As part of licensing and regulatory approvals, facilities must plan for managing radioactive waste. While the term “nuclear waste” is often used, much of the waste produced is actually “radioactive waste”, and the bulk of this waste is classified as Low Level Waste (LLW) as part of normal operations.

LLW can contain higher levels of short-lived radioisotopes and lower levels of long-lived radioisotopes[7]. Australia has approximately 4146m3 of LLW[8]. This waste has been produced from OPAL reactor operations to produce nuclear medicines, oil and gas extraction, mining and mineral processes (just to name a few). The LLW is packaged and disposed of by near surface disposal (3-10m). Currently LLW is stored at several licenced sites around Australia awaiting disposal. LLW has been successfully disposed of in Western Australia since 1992 in both state owned and private commercial facilities.

The waste people are most concerned about is the used fuel which is not technically a waste until it has no further use. Australia has approximately 150 used fuel elements at Lucas Heights[9]. The used fuel is temporarily stored in cooling ponds unit the residual heat has decayed away (this varies per fuel/reactor type). At this stage the fuel can be recycled. In the Australian context, our used fuel is sent overseas to be recycled. This process involves uranium and plutonium isotopes being extracted and recycled into other fuel types for reactors overseas. The remaining radioisotopes are packaged and classified as Intermediate Level Waste (ILW) and returned to Australia for storage. ILW contains higher levels of long-lived radioisotopes and can be safely disposed at depths up to a few hundred metres[10]. While Australia does not have a national repository for LLW and ILW, the establishment of the Australian Radioactive Waste Agency (ARWA)[11] in 2020 is tasked with finding a suitable site to safely isolate radioactive waste from humans and the environment now and into the future.

The last classification of waste is High Level Waste (HLW) Australia does not currently have any HLW, however this will change once we operate nuclear powered submarines. This is waste that contains radioactivity that can generate significant amounts of residual heat during the radioactive decay process[12]. Best practice disposal for HLW is in a deep, stable geological formations several hundred metres below the surface. Finland is about to commence operations on a world first deep geological repository for waste[13]. Defence and ARWA will need to plan long term HLW disposal as the AUKUS program develops.

How is nuclear regulated?

The nuclear industry is a highly regulated industry (even more than the pharmaceutical, food safety and aviation industries). International best practice is shared through the International Atomic Energy Agency (IAEA)[14], based in Vienna and a part of the United Nations. In Australia we have two (soon to be three) regulators that are highly regarded by the International nuclear community and IAEA to ensure nuclear and radiological facilities are compliant with national and international laws and regulations in regard to three key aspects:

• nuclear safety,
• nuclear security, and
• nuclear safeguards.

Safety and radiological security is regulated by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) based predominately out of Melbourne[15]. They already regulate Defence from a radiation protection perspective, some calibration tools and equipment house radioactive sources, as do soil density gauges as an example. Nuclear security and safeguards are regulated by the Australian Safeguards and Non-Proliferation Office (ASNO)[16]. Soon there will be a third regulator who will focus on naval nuclear-powered safety, named the Australian Naval Nuclear Powered Safety Regulator (ANNPSR).

What are the opportunities?

The real opportunity for nuclear power in Australia is to support stable power generation for industries that require either industrial heat (metal smelting, manufacturing and processing for example), or power stability/reliability (think climate controlled and high-power demanding data and AI centres). From an Australian Army context, there is also opportunity in the deployable power and energy space. In 2016, the US Army embarked on a program to develop a micro reactor for deployable power an energy named Project Pele[17]. Think a nuclear reactor on the back of a truck that you could deploy via air, sea or road, to produce enough power for a deployable force HQ where you can charge electric vehicles and other electronic equipment while also running a command centre using data intensive IT systems as an example. Or the ability to rapidly deploy power to a community devastated by a natural disaster to help with recovery. Project Pele is currently in its prototype phase will be interesting to watch as it develops[18].

Where can I learn more?

It's understandable that the word nuclear sometimes evokes emotive responses due to Australia, and Pacific neighbour’s historical baggage from atomic testing. This means that where there are gaps in nuclear knowledge, it is filled with fear. How we as a nation can overcome this fear and see what opportunities nuclear science and technology can provide us, we need to arm ourselves with good knowledge. This allows us to ask the tough questions and ensure we continue to be prosperous.

There are some great resources out there is you want to learn more:

Australian Nuclear Science and Technology Organisation - https://www.ansto.com
Australian Radiation Protection and Nuclear Safety Agency - https://www.arpansa.gov.au 
World Nuclear Association - https://world-nuclear.org
International Atomic Energy Agency - https://www.iaea.org
US Department of Energy – https://www.energy.gov/ne/office-nuclear-energy

Footnotes