The process by which the options were assessed is described in detail in section 5 and annexe B of the White Paper “The Future of the United Kingdom’s Nuclear Deterrent” (Cm 6994), published on 4 December 2006. Copies of the White Paper are available in the Library of the House.
A number of factors determined the estimate (set out in paragraph 5-14 of the White Paper: “The Future of the United Kingdom’s Nuclear Deterrent” (Cm 6994), published on 4 December) of the expected in-service costs of the UK nuclear deterrent once a new fleet of SSBNs comes into service. The estimate drew on: projections based on the actual and planned future maintenance and operating costs of the current system, including manpower costs; assessments of in-service costs of system components; studies of potential infrastructure and disposal costs; projected costs of the Atomic Weapons Establishment; and an assessment of the impact of risk.
The estimate of the lifetime operating costs of Trident provided by the MOD to the House of Commons Defence Committee in 1993, shortly before the first of the Vanguard class submarines, HMS Vanguard, entered operational service, included projections for: manpower and related costs of the crews of the submarines and associated civilian staff; the costs of refits of the submarines over the lifetime of the force; the costs of stores and stores personnel and transport; a share of the running costs of the Clyde submarine base; the costs of the Atomic Weapons Establishment; in-service support of the strategic weapons system and the submarine; and decommissioning and disposal of the submarines.