1. A note estimating
the decommissioning costs of the Vanguard-class SSBNs in the event
that a decision was taken to abandon the nuclear deterrent now
It is not possible to provide a precise estimate
of the costs that would be incurred in decommissioning the four
Vanguard-class submarines in the hypothetical circumstances that
a decision was taken to abandon the nuclear deterrent now. In
the Government's response to the Committee's report on The
Future of the UK's Strategic Nuclear Deterrent: the Manufacturing
and Skills Base we explained that the MoD's strategy for de-commissioning
nuclear-powered submarines is currently under review in the light
of revised project proposals for de-fuelling facilities and the
2006 report of the Committee on Radioactive Waste Management.
Under current arrangements, when nuclear powered
submarines are withdrawn from service they are defuelled as soon
as is practicable and stored afloat. A longer term solution to
submarine dismantling and disposal with interim storage on land
of the arising intermediate level radioactive waste is being sought.
If the Vanguard-class submarines were to be withdrawn from service
now, the main difficulty would be provision of suitable lay-up
berths until they could enter the proposed submarine dismantling
The MoD has made provision in its forward plans
for the decommissioning of the Vanguard-class submarines, and
other in-service submarines, when they reach the end of their
planned operating lives. These plans, together with provision
for the berthing and decommissioning of out of service submarines,
are reflected in the £9,753,827,000 undiscounted nuclear
liabilities, stated in the MoD Annual Report and Accounts for
2005-06 (HC1394). £837 million is included for the decommissioning
of submarines, up to and including Vanguard-class.
2. A note outlining how the support costs
of £600 million per annum are divided between SSBNs and SSNs,
and estimating how much would be saved if the SSBNs were no longer
operated [Q 339-340].
We estimate that the current cost of supporting
the SSBN and SSN fleets averages around £600 million a year.
This figure covers the costs of maintaining the submarines themselves,
including for replacement parts and systems, equipment and the
operating costs of the naval bases that provide support. It does
not include costs associated with supporting the strategic weapons
system (ie the missiles and their launch systems and the warheads)
installed on the SSBNs.
On average the £600 million is divided
more or less evenly between the SSBN and SSN fleets, but there
is some variation from year to year reflecting peaks and troughs
in major maintenance periods. A substantial proportion of these
submarine support costs (around 80%) are considered to be fixed,
that is they are not directly activity dependent. Ending SSBN
operations could therefore be expected to generate only relatively
modest savings in submarine support costs, of less than £100
million a year.
3. The estimated in-service costs of the
UK's nuclear deterrent, expressed in monetary terms instead of
percentage of the defence budget [Q345].
We have previously said that the annual expenditure
on capital and running costs of the Trident nuclear deterrent,
including the costs of the Atomic Weapons Establishment (AWE),
is expected to be between 5 and 5.5% of the defence budget. That
estimate was based on the planned near cash defence budget of
£28,700 million in 2006-07. We estimated that actual expenditure
would be around £1,500 million.
4. A note outlining when each of the existing
Vanguard-class SSBNs are due to leave service, when each of the
new generation of SSBNs will enter service, when a decision is
required on whether to procure a fourth boat in the fleet of successor
SSBNs, and how the MoD will evaluate whether it can operate continuous-at-sea
deterrence with three rather than four SSBNs [Q 383].
The dates when the four Vanguard class submarines
are due to leave service, with or without a life-extension programme,
were set out in the attachment to the letter from the MoD Liaison
Officer to the Clerk of the Defence Committee, dated 1 February
We plan that the first of the new submarines
will enter service around the time that HMS Victorious leaves
service (ie around 2024) and that subsequent new boats will enter
service as each Vanguard-boat is withdrawn. However, the precise
management of the transition between the two classes of submarines
will depend on a range of factors, including the number of new
boats to be procured, and the availability of the Vanguard-class
submarines as they reach the end of their lives.
As the White Paper makes clear, we will not
be in a position to make a final decision on the number of hulls
to be procured until we have a clearer idea of the design of the
new submarines and their likely operational availability. A final
decision on this is not essential for some years, but it may prove
to be cost effective to take this decision earlier than is absolutely
essential in order to inform and help focus subsequent detailed
A key part of the forthcoming concept and assessment
phase will be to determine the key design parameters of the new
submarines. We will also need to review the operating, manning,
training and support arrangements. This in turn will enable us
to judge the likely availability of the new submarines and hence
the risks associated with seeking to maintain continuous at sea
deterrence with a fleet of three submarines. We will also assess
the potential financial savings from this approach. This will
enable a final judgement to be taken on the cost-effectiveness
of a three versus a four boat solution.
19 February 2007