Nuclear propulsion and small modular reactors go together

Australia is embarked on the doubling of our submarine force with active programs committed to the new Attack Class by Naval Group and the life extension of the currently serving Collins Class, both classes conventionally powered. The graduation to nuclear propulsion for a future submarine class has been debated since 2009 without any real progress, mainly due to the lack of a nuclear industry arising from the legislative bans on nuclear power. But times are a-changing, as a recent study has presaged.

In July the Engineers Australia Sydney Division Nuclear Engineering Panel [NEP] hosted a Webinar by Professor Stephen Wilson of the University of Queensland on the subject of ‘Requirements for Operational Nuclear Plants in Australia from the 2030s – Preliminary Concept Study’, based on a recent study conducted by a team of students and their mentors. The webinar attracted more than 400 registrations.

The talk focused on the imminent implementation of small modular (nuclear) reactors universally known by their acronym SMRs. These new systems are innovative in several fundamental respects: firstly, they are designed to be inherently safe requiring no external actions to ensure safe shut-down and do not require large quantities of cooling water for normal operation or shut-down. The emergency planning zone does not extend beyond the site boundary.

Secondly, they are small enough for the reactor modules to be transportable by road, rail and waterborne transport and may therefore be prefabricated at a factory thereby reducing cost and ensuring high quality and reliability of manufacturing.

Thirdly, modules can be added as demand increases, with income from operation helping to pay for future modules. Hence, the initial capital cost is much lower than for large nuclear plants and financing is easier.

Other major advantages contribute to favourable economics compared with other zero-emissions energy sources such as a very long operating life. The life-cycle cost of construction, operation and disposal will produce a competitive levelised cost of energy, expected to be demonstrated by the end of this decade in the first international SMR deployments underway in the US, UK and China.

Professor Wilson delivered a comprehensive description of the study his team had undertaken, the report for which is in final university faculty review before publication later this year. He covered the study in some 12 segments that included significant insights as follows:

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• Background: Australia’s existing fleet of coal-fired power generating stations is coming to its end of life requiring significant investment in new zero-emission energy sources. The advent of SMRs is well-timed to form part of the new investment and is expected to provide significant advantages over wind and solar plus storage in economic terms as well as the recognised superior safety record of nuclear power plants.
• Australia today: We have significant experience, and relevant expertise in nuclear and large scale, complex engineering projects that would readily cover the needs of SMR development and implementation. Even if the processing of our extensive uranium resources into fuel assemblies was initially undertaken offshore, the installation, operation, refuelling and ultimate defueling, decontamination and disposal of radioactive waste is well within current Australian capability.
• SMR technology: Professor Wilson described the main features of SMR technology and emphasised the revolutionary progress made compared with the large current nuclear stations in operation worldwide.
• Example: NuScale. The study selected the NuScale plant which has received design approval in the US and is well suited for Australia. Designs with up-to-12 modules per plant could be initially sized to match the needs of the Australian east coast electrical generation requirements with additional modules added as required. The workforce required for a typical NuScale plant is around 270 including some 45 degree-qualified engineers and scientists.
• Feasibility: Australia’s installation and operation of the OPAL reactor at ANSTO Lucas Heights well demonstrated the capability to acquire an overseas nuclear reactor plant design for safe and efficient installation and operation here.
• Legal aspects: The introduction of nuclear power in Australia is currently inhibited by several federal and state legislative acts, with the most important being the 1999 Environmental Protection and Biodiversity Conservation Act, which prohibits nuclear installations for fuel fabrication, power generation, enrichment or reprocessing. There are compelling arguments for the repeal of these laws but there is a need first to achieve social licence.
• Regulation: Australia already provides effective regulation of nuclear activities through the Australian Radiation Protection and Nuclear Safety Agency [ARPANSA] and that would only need to be extended for SMRs.
• Energy security: The volatility of renewable energy sources that mandate large-scale energy storage and other compensatory factors, would be avoided with dispatchable continuously running nuclear. With a modular site such as NuScale, the refuelling would proceed module by module avoiding any shut down of the entire plant.
• Society acceptance: The major challenge with a relatively poorly informed society lacking adequate factual and balanced information. This is where the main focus will need to be placed for acceptance of SMRs in Australia by 2030.
• Siting: SMRs have a small footprint which would permit the first plants to be sited where the existing coal-fired plants will be shutting down. Beyond that there is good flexibility to meet regional demands for industrial heat, for energy and for community employment without the need for extensive water supplies for cooling.
• Economics: The economic modelling for nuclear is complicated by the long-term investments needed but as the study report will show, scalable nuclear can be favourably and predictably priced over the life of the investment.

Professor Wilson concluded with an optimistic discussion of the 10 elements required for the introduction of nuclear power. Against his expectations, the study has revealed that only two of those elements are not already in place. These are the lifting of the federal and states' bans on nuclear power and the social licence for the introduction of nuclear power to Australia.

So, the major impediment for nuclear propulsion could be removed within a decade and that would fit nicely with a commitment to nuclear propulsion for the expansion of the Australian submarine force to 12 boats with the latter six being nuclear propelled. There are many potential synergies in such an approach. The social licence will come with continuing advocacy and community attention to environmental, social and governance issues, and the legislative bans will be revised to follow.

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Christopher Skinner served 30 years in the Australian Navy as a weapons and electrical engineer officer in six surface warships. His interest in nuclear power for submarines is more recent and is reflected in his membership of the Engineers Australia, Sydney Division Nuclear Engineering Panel, the Australian Nuclear Association and the American Nuclear Society. He is also associated with several other organisations and institutes engaged in geopolitics, technology and submarine matters. The views expressed above are entirely those of the author and are not endorsed by any of the organisations of which he is a member.