If France sold Barracuda SSNs to Australia and, because they use LEU, France agreed to accept Australian Barracudas (including spent LEU) being returned to France this may be attractive to Australia.
This is because clauses of the AUKUS agreement require:
1. (reported but actual wording SECRET) a Low to Intermediate level nuclear waste Dump being built in Australia for waste arising from US and Australian Virginia and SSN-AUKUS maintenance. The dump will be at Fleet Base West ie. Perth Naval Base.
2. (actual wording SECRET) Australia must dispose of high level radioactive materials and Australian Virginia and Australian SSN-AUKUS subs once these SSNs are decommissioned.
3. (TOP SECRET) - The UK will bear much of the SSN-AUKUS burden for Australia if Australia accepts all/some part of the irradiated reactor compartments of the UK's decommissioned SSNs and SSBNs including High Level Radioactive waste, in a future Australian High Level Nuclear Waste Dump.
See AUKUS Briefing Book https://securityanddefenceplus.plusalliance.org/aukus-briefing-book/ and AUKUS Factsheet contains a complex and ambiguous network of overlapping responsibilities. See below official AUKUS flow chart. Nuclear Waste Dumps for Australia may be under "Nuclear Stewardship" and/or "Non-Proliferation" and/or, more explicitly, under one of the three "Classified or Not Disclosed" activities under "Submarines" below.
Off Topic - One of the "Classified or Not Disclosed" activities would be a Security Liaison Group mainly led by the FBI, ASIO (here and here) and MI5. They would be making high level decisions on Counter Espionage, Foreign Interference, Cybersecurity and high level Vetting as those topics relate to AUKUS.
