British Nuclear Weapons and the Test Ban 1954–1973

Britain, the United States, Weapons Policies and Nuclear Testing: Tensions and Contradictions

John R. Walker

• Publisher: Routledge
• Year: 2016
• Print ISBN: 9781409411123
• eBook ISBN: 9781317171690
• Edition: 1
• Topic: Technik & Maschinenbau
• Subtopic: Weltgeschichte

In 1962 Dean Acheson famously described Britain as having lost an Empire but not yet found a role. Perhaps nowhere is this more apparent than in the realms of nuclear weapons. An increasingly marginal world power, successive post-war British governments felt that an independent nuclear deterrent was essential if the country was to remain at the top table of world diplomacy. Focusing on a key twenty-year period, this study explores Britain's role in efforts to bring about a nuclear test ban treaty between 1954 and 1973. Taking a broadly chronological approach, it examines the nature of defence planning, the scientific goals that nuclear tests were designed to secure, Anglo-American relationships, the efficacy of British diplomacy and its contribution to arms control and disarmament. A key theme of the study is to show how the UK managed to balance the conflicting pressures created by its determination to remain a credible nuclear power whilst wanting to pursue disarmament objectives, and how these pressures shifted over the period in question. Based on a wealth of primary sources this book opens up the largely ignored subject of the impact of arms control on the UK nuclear weapons programme. Its appraisal of the relationship between the requirements and developments of the UK nuclear weapons programme against international and domestic pressures for a test ban treaty will be of interest to anyone studying post-war British defence and foreign policy, history of science, arms control, disarmament and non-proliferation and international relations. It also provides important background information on current events involving nuclear proliferation and disarmament.

Chapter 1 Introduction

DOI: 10.4324/9781315570211-1

Historians have thus far ignored the impact of arms control on the UK nuclear weapons programme. Yet given the wealth of material now available in the National Archives, it is possible to undertake a detailed review of the one arms control issue that could have had the most impact on the nascent British weapons development programme, a test ban. There was also the possibility of a freeze on fissile material production, but it is arguable that a comprehensive test-ban treaty, had it come about, would have brought an end to UK weapon development in the 1950s. Parallel developments were occurring in the arcane world of warhead design and UK strategic and tactical nuclear plans and the rather more public arena of international negotiations for an end to all nuclear weapons testing. There were times when UK nuclear weapon objectives were contradictory and this story is as much about the Eden and Macmillan Conservative governments’ attempts to square this circle as it is about warhead R&D. This story also involves an exploration of the nature of defence planning, Anglo-American relationships, the efficacy of British diplomacy and UK contributions to arms control and disarmament, both at the general and detailed technical levels. A key question for this study is to see just how the UK managed to balance the conflicting pressures created by its determination to become and remain a credible nuclear power whilst wanting to pursue disarmament objectives. The relative weight of these pressures changed over the period in question – 1954 to 1973 in response to both domestic and international imperatives. Charting these changes and their relationships is another key question to address in this study.

Whilst all this was going on at the diplomatic and political level, Britain struggled to build and sustain an effective nuclear weapons stockpile throughout the late 1950s, 1960s and early 1970s. This book will deal with the interrelationships and contradictions between the test ban and weapons development by providing a narrative of the key events that shaped this aspect of British nuclear weapons history. The Conservative governments of Harold Macmillan were stalwart supporters of the ban and played a key role the bringing about the Partial Test-Ban Treaty in 1963.¹ Between 1958 and 1962 the UK, along with the US and the USSR, participated in the Tripartite Conferences on the Discontinuance of Nuclear Weapon Tests, which sought to produce a comprehensive ban on all types of nuclear tests save for peaceful nuclear explosions in specific circumstances. The UK’s involvement in these efforts at some of the key stages is highly significant, in particular how UK Ministers and officials pursued or reacted to arms control and disarmament initiatives. What is being offered here is not a detailed blow-by-blow account of the long and painful negotiations that took place in the Geneva-based Conference on the Discontinuance of Nuclear Weapon Tests. Rather it will highlight some of the key events and issues that help illuminate UK thinking and attitudes to working with the US; to verification; to wider nuclear arms control negotiations; and to the relationship between its own weapons programme requirements and arms control imperatives. Inevitably there will be some detailed narrative describing the chronology of some of the events in this period, which is necessary to help us understand the nature of UK thinking and rationales at particular moments in our story. The extensive footnoting is quite deliberate. A key objective of the Arts and Humanities Research Council (AHRC) funded UK Nuclear Weapons History project at the Mountbatten Centre was to provide a reference for other scholars who wish to explore some of the issues affecting the nuclear weapons programme, as well as its relationship to arms control, in much greater detail. A good deal of the available archival material has only been summarised in some places here. More detailed accounts of many aspects of this story could be produced, such as the procurement and deployment histories of individual nuclear weapons, or British attitudes to the institutional aspects of future test-ban treaty implementation. This book is not the final word.

1 Kendrick Oliver, Kennedy, Macmillan and the Nuclear Test-Ban Debate, 1961–63 (Basingstoke, 1998), p. 209.

Chapter 2 will look at the early pressures between 1954 and 1958; the UN Disarmament Committee and the Grapple tests; pre-1954 UK-US relations; AWRE’s first attempts at thermonuclear designs and tests; and the growing public and international concerns. As well as the key Antler tests in Australia, Chapter 3 will examine the decisive year of 1958, which witnessed the successful planning and conduct of the Grapple Y and Z tests and which coincided with pressures for a moratorium and the resumption of the UK-US nuclear relationship with signing of the 1958 and 1959 Mutual Defence Agreements. Chapter 4 will look at the testing moratorium and how it impacted on the development of the first UK megaton range weapons: Yellow Sun; the US-designed Mark 28 warhead and its UK counterpart Red Snow; and the critical role that the Assessment Trials in Australia played in warhead design and adoption. Future UK test requirements and options will also be reviewed. Chapter 5 covers the testing moratorium and British responses to US policies. The Tripartite Conference on the Discontinuance of Nuclear Tests opened in 1958 and the latter part of this chapter will chronicle UK objectives and role in the Conference between 1958 and 1961 as well as Anglo-American differences. British efforts to solve the test-ban verification problems are reviewed in Chapter 6, which also provides the first detailed examination of the emergence of forensic seismology in the UK. This looks at the extent to which seismic research in the UK underpinned British approaches to test-ban verification. Chapter 7 begins with the end of the testing moratorium in 1961 and UK responses – a test of the new implosion system Super Octopus and other nuclear tests. The US request to use Christmas Island and the resumption of atmospheric testing presented significant problems and opportunities for the UK. Also, the Discontinuance Conference came to an end in 1962 and the shift of test-ban negotiations moving to the Eighteen Nation Disarmament Committee (ENDC). Chapter 8 deals with the lead up to, and participation by the UK in the Partial Test-Ban Treaty (PTBT) 1962 to 1963. Chapter 9 looks at the testing plans in the 1963–65 period including the Polaris warhead and WE177; UKAEA’s proposed research test programme in 1964; the Polaris Economy tests; the arrival of Labour; and the impact on the testing and weapons programme of its 1965 defence review. British policy towards a CTBT from the mid 1960s until the early 1970s is reviewed in Chapter 10; this looks at the decline in superpower interest in the test ban and UK efforts to address the verification issues. Chapter 11 deals in detail with AWRE’s future and the Kings Norton review; the Wilson government’s nuclear policy review (no new strategic weapons); first steps in the Polaris Modernisation debate leading to Antelope, Super Antelope, STAG, Hybrid, Option M and Chevaline choices being addressed in 1966–73; and the decline and revival of Anglo-American nuclear relationship. As this modernisation work progressed the British return to testing with the UK effects tests and the decision to resume underground testing and the impact of this on CTBT policy is also examined. Finally, the concluding chapter will discuss how priorities were reconciled; when a test ban was a subordinate objective to the weapon programme requirements and when these priorities were reversed; the nature and impact of the UK-US relationship on UK test-ban policies; and the problems in acquiring and sustaining an effective and credible nuclear deterrent. Finally, the lessons of the British experience generally and for arms control and non-proliferation are reviewed in Chapter 12.

We should not forget that writing nuclear weapons history faces certain problems. These include very high levels of security and compartmented information systems that existed during the Cold War period – a strict need to know policy where only a handful of individuals were privy to the information; complex, diverse and changing bureaucratic structures responsible for or related to nuclear policy and implementation; changing understandings over time of the basic science and engineering of nuclear weapons; continued closure of archival material beyond the 30-year rule; sometimes contradictory and misleading evidence in open archives; and an ever diminishing band of original participants. None of these are new or novel. Given such obstacles historians might be forgiven if they decided to abandon any attempt at writing a comprehensive account of the UK nuclear weapons programme. However, the picture is not all bad; there is a surprisingly large amount of archival material available in The National Archives at Kew and in other places that enable a reconstruction of the detailed broad themes and directions of the UK programme. We can supplement archives with oral histories. The key is to be aware of the partial nature of the picture that might be painted and avoid extravagant claims based on limited evidence. Much can then be said about the UK programme, certainly in terms of main thrusts of policy, policies, rationales and a good deal too on the weapons systems themselves.

The threat (or opportunity) of a test-ban treaty hung over the UK nuclear weapons programme for much of the period covered by this book; the interrelationships changed over time as programme and international pressures varied. Exactly how these interrelationships operated at particular moments in time will, hopefully, become clearer in the following chapters.

Chapter 2 Early Pressures: 1954–1958

DOI: 10.4324/9781315570211-2

Introduction

The way in which the UK managed to cope with two diametrically opposed policy requirements in this period – being seen to favour limitations on testing, whilst resisting them at the same time as the national weapons programme strived to meet its demanding goals – has not been examined in detail before with the benefit of official papers. What ideas did the UK have on possible constraints on nuclear testing and to what extent were these driven by the need to be seen to respond to domestic and international concerns over atmospheric testing of megaton warheads. How did the UK’s own nuclear testing programme, planned weapons deployments and test-ban pressures interact in this formative period? Could the UK demonstrate that it knew how to design, build and test successfully an H-Bomb before a test ban came into force?

Opening Gambits: The Thermonuclear Test Programme and Pressure for Cessation

International pressure for an end to atmospheric nuclear testing in the mid and late 1950s coincided with a key moment in the development of the British nuclear weapons programme. The Cabinet Defence Committee decided in 1954 that the UK should possess thermonuclear weapons and Aldermaston embarked on a crash programme to meet this requirement.¹ Politically the UK faced what appeared to be irreconcilable objectives: the need for thermonuclear weapons and the need to be seen to address domestic and international public concerns over the health, environmental and international security effects of nuclear tests. Sir Michael Wright, leader of the UK delegation to the 1958–62 negotiations for much of their existence, remarked in 1961 that it was not until the amendment of the 1954 US Atomic Energy Act that enabled the UK to access US know-how that the UK became committed supporters of a stand-alone test-ban treaty.² A key feature of this period was that AWRE was, as Arnold and Smith observe, working under pressure to complete its R&D programme as quickly as possible to beat the inevitable ban on nuclear testing.³

1 Lorna Arnold, Britain and the H-Bomb (Basingstoke, 2001), pp. 110–11. 2 The National Archives (TNA) FO 371/157105, IAD 22/426/G, Geneva Nuclear Tests Conference: Review of Events to September 9, 1961 Sir Michael Wright to Lord Home (Received September 27) p. 3. 3 Lorna Arnold and Mark Smith, Britain, Australia and the Bomb, The Nuclear Tests and Their Aftermath (Basingstoke, 2006), p. 86; see also pp. 82–5 for the context in which test-ban pressures grew.

A joint MOD and UKAEA report noted in August 1955 that since international prestige was, at that time, so closely associated with prowess on the nuclear field, it was essential to avoid any agreement on prohibition of tests until the UK had conducted a successful test of a megaton weapon. Abolition of full-scale trials would seriously impede Britain’s ability to make reliable megaton weapons, and it would therefore never possess any valid nuclear deterrent in the future when, if nuclear disarmament negotiations succeeded, the UK would have to live with the possibility of the clandestine Soviet retention of such weapons. In such circumstances, the only policy open to the UK was to let others make the suggestions on test bans and to try to influence US policy if Washington showed signs of agreeing to a complete abolition of tests.⁴ Given the rising tide of public opinion against the further testing of thermonuclear weapons, it was imperative that the first UK trial take place as early as possible. For this reason, as Lt Gen Frederick Morgan, Controller of Atomic Weapons, Ministry of Supply, told the Atomic Weapons Trials Executive, the date for them was provisionally fixed as April/May 1957.⁵

4 TNA AB 38/515, Operation Circus: a plutonium safeguards exercise 1955–58, Control of Atomic Weapons Prepared by B.T. Price and V.H.B. Macklen Part I. 5 TNA AVIA 65/827, Operation Gazette minutes of a meeting held on 1 September 1955.

The Defence Research Policy Committee (Atomic Energy Sub-committee) (DRPC (AES)) informed the Chiefs of Staff in mid December 1955 that political pressure in the UK and throughout the world against further megaton trials was increasing, despite the firm stand taken by HMG in parliament. It was thus possible that the UK’s first megaton trials would have to be abandoned on political grounds. It was therefore essential that the series should be planned in such a way as to safeguard the future by obtaining the greatest possible amount of scientific knowledge and weapon design experience from them, to create a sound foundation for the UK’s megaton development programme.⁶ MOD opposition to even a one-year limitation on testing was considerable.⁷ Eden himself informed the House of Commons that the UK would not accept arrangements that would put itself in a position of decisive inferiority to other great powers. That said, the UK was prepared to discuss methods of regulating and limiting test explosions that took account of the UK’s position as well as that of other powers.⁸ At that time the limitations of British knowledge meant that the most certain way of producing a trial megaton explosion in 1957 was to use a large fission assembly in a Blue Danube ballistic case. Such a device would be big, heavy and extravagant in fissile material and could only be used as a free falling bomb. Sir William Penney (Director, AWRE) told the Chiefs in December 1955 when they met to discuss the DRPC (AES) paper that he would have preferred that the trial of Orange Herald (a small light megaton warhead for the Blue Streak intermediate range ballistic missile) should not be carried out in 1957 as this missile would not enter production until 1965. However, the danger that trials might be banned at some time in the near future made it essential that the UK should take every opportunity to test when it could.⁹

6 TNA AIR 8/2468, COS Committee The British Megaton Warhead Trial Series Report by the Ato...

Table of contents

• Cover Page
• Half Title Page
• Dedication
• Title Page
• Copyright Page
• Table of Contents
• List of Abbreviations
• Chronology of UK Nuclear Tests, Testing Moratoria and Test-Ban Treaty Negotiations 1952–1974
• Acknowledgements
• 1 Introduction
• 2 Early Pressures: 1954–1958
• 3 1958: A Decisive Year
• 4 The Testing Moratorium and Its Constraints on UK Weapons: 1958–1963
• 5 Diplomatic Pressures and the Testing Moratorium: 1958–1961
• 6 Test-Ban Treaty Verification and the Role of Seismology: UK Efforts 1958–1965
• 7 The End of the Testing Moratorium 1961: UK Responses
• 8 The UK and the Partial Test-Ban Treaty (PTBT): 1963
• 9 UK Testing and Future Plans 1963–1965
• 10 UK CTBT Policy 1965–1973
• 11 A Static UK Nuclear Weapon Development Programme 1966–1973
• 12 Conclusions
• Bibliography
• Index