The US is also adding to the pot
https://www.smh.com.au/politics/federal/new-fleet-of-eight-nuclear-submarines-to-be-built-in-australia-in-368-billion-deal-20230314-p5crt9.html
Australia will contribute about $3 billion to the efforts in the US and UK to develop the submarine technology, including the design and development of the SSN-AUKUS.
The US will commit $US4.6 billion ($6.9 billion) to its industry to support the Australian project, while the UK will spend £2.2 billion ($4 billion).