---

Nuclear Submarines

Of course, as the right hon. Gentleman might anticipate, those are questions that I have already asked of the programme managers throughout this process. There are technical factors in the design of the core that limit the scope to change aspects of the design, but now that we are aware that this microscopic breach has occurred in the test reactor, it will focus the examination of the as yet uninstalled cores that are being built for the Astute class of submarine.

The test reactor at Dounreay has been hammered. This is the nuclear equivalent of putting an engine on a test bed and running it flat out at maximum revs to see what happens. It does not mean that what happens to that engine will happen in a car that is being driven normally on the roads.

It will take approximately three years from the time of decommissioning the reactor to being able to examine it fully. We now have to make a decision about whether more will be learned by continuing to run the reactor at Dounreay until its intended decommissioning date in 2015 or by decommissioning it a year and a half early and thus being able to examine the core a year and a half earlier than we otherwise would. The balance needs to be struck on that and I will act on the best scientific advice that I receive.