Nuclear-powered vessels visit Australian ports under strict protocols.  The likelihood of an incident resulting in radiological consequences to the population is extremely low. Should an incident occur, detailed response plans and procedures are in place to protect people and the environment.

What are nuclear-powered vessels?

A nuclear-powered vessel (NPV) is a ship or submarine that is powered by a nuclear reactor. This allows NPVs to operate at sea for much longer periods than conventionally powered vessels.  

The design considerations and operating requirements for an NPV are quite different to a commercial nuclear reactor. Naval nuclear-powered vessel reactors tend to be smaller and lower in power rating than a typical commercial reactor. The power level is set primarily by operational and propulsion needs, which means that reactors can be operated at a low-power state after arrival in port and returned to a higher power state to enable departure from the port. Power for other service needs can be provided from onshore non-nuclear power supplies while in port. This means that there is less hazardous radioactive material present in the reactor in the event of an accident as many radionuclides decay quickly. 

Naval nuclear-powered vessel reactors must be designed to withstand combat shocks, while protecting the crew that live and work near the reactor against radiation hazards. These factors contribute to high levels of safety in NPV reactors. 

What are the risks of nuclear-powered vessels?

The likelihood of an incident resulting in radiological consequences to the population is extremely low. Detailed emergency response plans are developed and exercised before any Australian port receives a visit from an NPV. These plans are informed by the Reference Incident, which models a potential severe accident and ensures that the Australian public is kept safe in the unlikely event of an emergency. Details on the reference incident can be found here. 

While at port, there are strict controls which ensure there is no harmful discharge of radioactive materials into the environment. Our environmental monitoring program for visiting NPVs can be found here. 

Does Australia have nuclear-powered vessels?

Australia does not currently own or operate nuclear-powered vessels. In March 2023, the government announced the Optimal Pathway to acquire Australian nuclear-powered submarines as soon as the early 2030s. 

Why do nuclear-powered vessels visit Australia?

Reciprocal port visits are part of defence cooperation between Australia and other nations. The vast majority of NPV visits Australia receives are from the United States, although we have received visits from British and French vessels as well. All visits are made with the approval of the Australian Government. 

Where to learn more

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