This essay is an enquiry into the roles scientists and engineers might make for themselves in an aging society. At its centre is a case study of an extraordinary response to a devastating event: a British project after Chernobyl to set up a cadre of volunteers, aged 65 or over, willing to act swiftly, expertly and, perhaps, expendably, in the wake of a nuclear emergency. Surprisingly obscure now, the would-be volunteers included many of the elite of British science and engineering. The episode is fascinating on many levels and invites several different analytical perspectives, which I will explore. However, the dimension that interests me most concerns primarily old age. Most obviously, the project mobilised an elderly population of elite experts, who felt themselves to be both qualified and occasionally disqualified to act because of their age. The project prompted them to reflect, soberly and insightfully, on the qualities and capacities of aged scientists and engineers, sometimes as self-reflection as individuals, sometimes as a group with identifiable characteristics. But there are other, just as interesting dimensions of age raised in the project. In particular, this generation felt responsible and protective over its achievements, not least the nuclear programmes of the second half of the twentieth century, and were willing to exchange physical jeopardy to secure its continuation.Furthermore, there is a dynamic social context to aging within which the generation who reached their 60s in the 1980s must be located: an aging society in which what it was to be old was changing both quantitatively and qualitatively. In terms of simple numbers more people in the West were living far beyond the traditional life span of three score and ten. Qualitatively, the period was marked by the articulation of ideas of a old age, a 'Third Age of activity before senescence, and a gerontological interest in successful aging. A proportion of the elderly are now seen as resilient, healthy, keen to stay in employment or to continue to be involved in social and community matters.1 A final twist that makes the examination of scientists and engineers attempt to carve out new roles in an aging society particularly meaningful is that this extension of life, in both senses, was seen as a product of scientific intervention.2EXPERTS, EXPERTISE AND THE BRITISH NUCLEAR PROJECTBritish involvement in nuclear weapon and power projects began during the Second World War. Following the calculations of the critical mass necessary to generate a chain reaction of uranium fission by the emigres Otto Frisch and Rudolf Peierls, working at the University of Birmingham, in 1940 the UK government set up the MAUD committee to establish the feasibility of an atomic bomb.3 As is well known, British efforts, beginning with the arrival in 1 943 of nineteen scientists at Los Alamos, were soon drawn in to the Manhattan Project. In December 1945, four months after Hiroshima and Nagasaki, prime minister Clement Attlee's GEN 75 Cabinet Committee on Atomic Energy, authorised the construction of an atomic reactor at Windscale on the Cumbrian coast. The aim was to produce plutonium. In 1946, the McMahon Act in the United States superseded previous UK-US agreements on the sharing of nuclear knowledge and responsibilities, and prohibited further transfer of information. Previously sceptical views (on economic grounds) in the British Cabinet were sidelined, and commitments made in 1946 and 1947 to complete a British nuclear bomb and to expand necessary research and development work. The institutional landscape of the British nuclear project was filled out, including the Atomic Energy Research Establishment at Harwell, the Atomic Weapons Research Establishment at Aldermaston, and a nuclear factory at Windscale. A British atomic bomb was first tested on the Monte Bello islands, Australia, in October 1952.The 1950s witnessed further institutionalisation and expansion of the British nuclear projects. …