This dissertation surveys the history of tritium beginning in Ernest Rutherford's lab in 1934 with its discovery and ending at the Fukushima Daiichi disaster site in 2023 when TEPCO began releasing tritiated wastewater into the Pacific ocean. In this time, expert conceptions of tritium have experienced interdependent and overlapping phases. Each phase is characterized by a dominant "nuclearity" and situated in context of "nuclear exceptionalism" (Hecht 2014) that directly and indirectly affects material conditions, elite decision-making, and radiological impacts on the environment and human health. Because it is pervasive, diffuse, and laborious to measure, a great deal of uncertainty surrounds tritium's contribution to radiological risks. Beyond various commercial and scientific uses, it is also integral to both nuclear energy as a waste and nuclear weapons as a mechanism for dramatically increasing explosive yields. This versatile and powerful material operates at the technological nexus of two existential risks for humanity: climate change and nuclear weapons.
I divide the history of tritium into three distinct phases. First, super nuclearity characterizes early designs for the "superbomb" by Manhattan project scientists who believed vast amounts of tritium would be required. This phase extends to the late 1950s when thermonuclear warheads based on more feasible designs requiring significantly less tritium were beginning to be incorporated into the U.S. nuclear weapon stockpile. Second, special nuclearity describes the status of tritium throughout the Cold War as a critical nuclear weapons material that was referred to and treated as a special nuclear material (SNM) in practice even though it was never legally defined as such. Third, byproduct nuclearity is the current post-Cold War paradigm defining tritium as a form of incidental waste or as an innocuous "other accountable material" intentionally produced by the nuclear fission process. While tritium's super nuclearity proved to be an animating fiction with political and material impacts on the early U.S. post war nuclear weapons program, tritium's special and byproduct nuclearities have since been fully embodied in technological artifacts—primarily nuclear weapons and nuclear power plants—and remain in dynamic tension.
Tritium does not fit neatly into existing nuclearity narratives. It is accurately referred to as both "highly" and "weakly" radioactive. Having a half-life of ~12 years and being the lightest radioisotope, it has high activity by weight, but when it decays into stable helium-3 it emits only a relatively weak beta particle which poses a potential risk as internal dose. I argue that the nuclearity processes constituting various conceptualizations of tritium provide insight into navigating the complex sociotechnical relationships between humans and nuclear technology. Additionally, I anticipate tritium's next nuclearity transformation as reactor fuel for a still nascent fusion power industry. I argue that rather than allowing fusion energy proponents to dictate the next phase of tritium's nuclearity, efforts should be made to assess and synthesize salient aspects of this unique material to provide a more holistic accounting of its risks, benefits, and tradeoffs. / Doctor of Philosophy / Hydrogen is the most abundant element in the universe. It fuels the stars and forms compounds like water that are essential to life. Most atoms of hydrogen contain one proton and one electron, but hydrogen also has two less common, naturally occurring "heavy" forms that additionally contain neutrons. One is deuterium, which contains one neutron and can be concentrated to make heavy water. The other type of hydrogen is tritium, which contains two neutrons. This dissertation is about tritium, an extremely rare and valuable material that can be used to produce a faint green light source without electricity, to increase the explosive power of nuclear weapons, or to fuel fusion power reactors. Tritium is also a radioactive waste material produced by both military and civilian nuclear activities.
I divide the history of tritium into three phases: super, special, and byproduct. When tritium was first discovered in 1934, it was an exotic scientific curiosity. During the 1940s, scientists with the Manhattan Project began working out how tritium could be weaponized into a "superbomb" that would be vastly more powerful than the atomic bombs the U.S. dropped on Japan in WWII. While the "superbomb" designs proved to be unviable, powerful hydrogen weapons were developed in the 1950s that relied on tritium alongside specially prepared masses of uranium and plutonium. To limit the spread of nuclear weapons, these special forms of uranium and plutonium have been tightly regulated as special nuclear material (SNM). Tritium, on the other hand, never met the legal definition of SNM but was nonetheless treated as a "special" material throughout the Cold War until the 1990s. Tritium has remained a critical material for all modern nuclear weapons, but in the last thirty years it has been primarily thought of and regulated as a byproduct material.
Because the radiological risks posed by tritium are ambiguous and technically challenging to measure at low concentrations, many proponents of nuclear technologies suggest that they are negligible and, at the same time, anti-nuclear activists claim that more research is needed to show tritium's dangers clearly. I argue that it is important to prioritize a more thorough assessment of tritium's radiological risks and role in nuclear weapons before the implementation of large-scale fusion technologies that will require the production of many thousands more times the amount of tritium currently available in the world.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/120638 |
| Date | 10 July 2024 |
| Creators | Loy, Taylor Andrew |
| Contributors | Science and Technology Studies, Collier, James H., Schmid, Sonja, Breslau, Daniel, Avey, Paul C., Pierson, Mark Alan |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | Creative Commons Attribution-NonCommercial 4.0 International, http://creativecommons.org/licenses/by-nc/4.0/ |
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