The National Audit Office published a report on 3 April 2019, following their investigation into submarine defueling and dismantling. The report acknowledges the complex nature of activities to defuel and dismantle our decommissioned submarines and includes the most recent information on the status of the submarines and projects involved.
The details can be found in Figure 5 of the report which is available at the following link:
We remain committed to the safe, secure and cost-effective defuelling and dismantling of our nuclear submarines as soon as is practically possible. This commitment is illustrated by the recent success with commencement of the initial dismantling of the submarine Swiftsure, which has been followed immediately by commencement of the initial dismantling of Resolution.