FUTURE UK NUCLEAR WARHEAD CAPABILITY

This comprehensive minute and accompanying report reflect the UK Ministry of Defence’s internal review of nuclear warhead capability and cost under the Long-Term Costing 1994 (LTC94) framework. Following the cancellation of the WE177 replacement programme, the review was commissioned to identify future policy choices and assess options for savings, capability retention, and independence from the United States. Key Points: 1. Current Cost Landscape and Savings Efficiency savings at the Atomic Weapons Establishment (AWE) are already assumed in LTC94. Further savings are unlikely unless MOD changes programme requirements or undertakes long-term site rationalisation. Site rationalisation could yield long-term savings but would require £70–100M investment and incur decommissioning costs potentially up to £100M. 2. Strategic Capability Options (Para 20–25) Five main capability options are presented, increasing in risk, cost, and independence: Option 0 (Base Case): Maintain Trident and replace it after 30 years without enhanced safety. Risk: Marginal capability and serious assumptions about warhead longevity. Option 1: Like Option 0 but with increased safety-related work and improved replacement warhead. Risk: Lower, but still vulnerable to testing bans and new safety demands. Option 2: Adds flexibility for improved performance and reliability under a test-ban regime. Option 3: Develop a new modern warhead for delivery around 2010 (air-launched or other) and maintain advanced design capability. Risk: Low; preserves most current capability. Options 4 & 5 (Supplementary): Measures to reduce UK dependence on US, such as: Option 4(i): Re-establishing UK tritium filling independence (£200M). Option 5: Retain penetration aids capability for ABM scenarios. Conclusion: Options 1 & 2 strike the best balance between cost and risk. Option 0 is risky; Option 3 offers resilience but at higher cost. Reducing US dependence (Options 4 & 5) is extremely costly and not justified without clear signs of waning US cooperation. 3. Dependence on the US UK currently relies on the US for: Tritium bottle filling (though UK supplies tritium). Technical components and design assistance. Maintaining cooperation is assumed, but reliance is a political and operational vulnerability. A full shift to independence would cost over £1 billion across 30 years. 4. Impact on UK Deterrent Posture Option 0 entails substantial risk to UK nuclear posture due to: Potential Trident warhead failures. Lack of modern safety features. Inability to respond to future delivery system changes or defensive technologies. Options 1–3 reduce this risk progressively. The Trident warhead is based on 1970s tech and may not meet future safety standards post-2020. 5. US–UK Nuclear Cooperation (1958 Agreement) US cooperation depends on UK maintaining a credible technical contribution. Base Case or Option 1/2 might reduce UK value in certain technical areas but do not threaten overall cooperation—unless US policy shifts drastically. Final Recommendation (Para 4): DUS(P) recommends the Secretary of State decide against Option 3 and Options 4–5 now, allowing AWE to cease related technical work and focus on rationalisation. Significance: This paper outlines the post-Cold War recalibration of the UK’s nuclear posture. It reveals early signs of contraction in warhead capability, long-term budget pressures, and a growing dependence on the US, while preserving some flexibility for future re-expansion.