Abstract

The Castle Bravo nuclear weapons test, in March 1954, was the worst radiological accident of the United States nuclear testing program, contaminating tens of thousands of square miles of the territory of the Marshall Islands, including several inhabited atolls, and exposing nearby Marshallese, American observers, and the crew of a Japanese fishing boat to harmful levels of radioactive fallout. Despite being a fixture of both popular and scholarly interest for the past 70 years, the underlying cause of the accident has only very recently been understood. The official explanations – that a change in wind conditions, coupled with an unexpectedly high-yield – are now known to have been incorrect and even deliberately misleading. Documents and reports declassified and released in the last decade or so in fact point to an entirely different cause of the accident: a fundamentally flawed and unsubstantiated theory of how fallout would form for megaton-range weapons. In this talk, I will focus on ‘what went wrong’ in the Bravo accident, what impact different causative mechanisms do to our historical (and possibly legal) narratives about the accident, and, ultimately, the practices of Cold War knowledge production that were arguably the ultimate ‘cause’ of the accident.