Originally Posted by
Asturias56
"I suspect that it will be a British designed hull with a US reactor (probably S9G)"
But then you lose commonalty with either the USN or the RN - and the cost of modding any design will be fearsome. If you want to be cost effective and minimise risks you buy off the shelf, and preferably from a long production line
An off the shelf Virginia would be the simplest build but would require a lot of regulatory changes. The Astute’s PWR2 reactor is out of production and doesn’t meet modern nuclear safety standards. The PWR3 is a much better reactor (based on the US S9G) and has a longer lasting core (>33 years) and has convective cooling capability but, as it’s designed for the Dreadnought class, can it be redesigned to fit in an Astute hull, or the even narrower Virginia hull?
If a British hull is selected, the RAN will require it to have the US combat system and weapons as that will be crucial to timely resupply in event of a conflict in this region. This will mean a large amount of redesign internally but, it’s a big improvement operationally. We’ll know a lot more on Monday.