The Tritium Matters Working Group emerged as a response to research challenges while writing my dissertation. My committee co-chairs, Sonja Schmid and Jim Collier, encouraged me to articulate my experience in a forward-looking project that provided a bold “what’s next?” vision. I wrote:

Throughout my research, particularly in the context of nuclear weapon reports and analyses, references to tritium were surprisingly sparse. With the notable exception of Peter Lobner’s thorough blog posts from 2020 for The Lyncean Group of San Diego, tritium is rarely a featured topic. Since I began outing myself as a tritium researcher on social media and at various workshops, I have received several requests to connect with other experts interested in tritium. Many of their stories are similar. They either study or work in the nuclear policy domain, and they devoted some time to the tritium topic before being drawn away to more salient research. Sometimes they tried and failed to engage colleagues on the topic, or they completed a short-term research program and simply moved on. Beyond a few research cohorts focused primarily on tritium science, there are no multi-disciplinary working groups considering the many dimensions of tritium covered in this dissertation. (81-82)

In fall 2024, I began reconnecting with and meeting new nuclear experts who expressed interest in diving deeper into the tritium topic. I also published some provocative pieces on tritium’s entanglement with civilian and military infrastructures: in Promoting Fusion Energy Leadership with U.S. Tritium Production Capacity I proposed technical and policy pathways for strategically leveraging defense production to supply startup fuel in first-of-a-kind fusion reactors; I consider How Military Tritium Production in Civilian Reactors Can Further Non-proliferation Goals in light of the emerging transparency into this highly classified process; and in Beyond Byproduct: Rethinking Tritium in Fusion Technologies I expand historical themes from my dissertation to propose a more holistic view of tritium. These efforts opened doors and started more tritium conversations, further convincing me that a multi-disciplinary tritium working group could play a key role in shaping discourse around this critical material. By ensuring that historically and technically informed perspectives are included in the conversation, we can promote a more credible and responsible accounting of tritium’s risks and rewards.

Multi-disciplinarity is important because it can help overcome the siloing of expertise. A burgeoning field of private fusion energy startups and national programs designed to accelerate R&D contend that their fusion futures are not entangled with contemporary nuclear fission concerns. And yet, to some degree, they are. If the technological enthusiasm for fusion is not appropriately tempered with nuclear expertise in weapons, nonproliferation, radiological protection, regulation, and policy, then these new, promising technologies may stumble at the gate.

A thorough consideration of tritium’s role in nuclear weapons is systematically approached in the work of Martin Kalinowski, a TMWG senior advisor. His 2004 monograph, International Control of Tritium for Nuclear Nonproliferation and Disarmament, remains a foundational contribution to this discussion. Despite Martin’s efforts, tritium’s potential to advance nonproliferation and disarmament goals has largely remained untapped. With the aim of reversing this trend, the TMWG will ensure that tritium is no longer an afterthought in these discussions. As part of our core mission, our group will engage with vanguard fusion research and the further development of regulatory oversight taking into account essential safeguards and novel radiological risks posed by these emerging technologies.

Before Kalinowski’s efforts, in 1988, the Tritium Factor workshop was convened to address the provocative suggestion that nuclear disarmament could be achieved by freezing the production of tritium and allowing arsenals to be reduced as a function of radioactive decay. Every ~12 years, stockpiles would decrease by half. This was a joint venture by the Nuclear Control Institute (NCI) and the American Academy of Arts and Sciences (AAAS) attended by an array of renowned nuclear weapon experts, academics, scientists, along with U.S. government and military officials. Another TMWG Senior Advisor, Robert Kelley, contributed a memo to the proceedings. While a tritium freeze did not receive much traction at the time, the out-of-print workshop summary marks an important milestone in the public consideration of tritium policy. Members of the TMWG are working on an updated and expanded re-issue of The Tritium Factor: Tritium's Impact on Nuclear Arms Reductions.

With the threat of a looming nuclear arms race and the promise of recent breakthroughs in fusion energy, understanding the role of tritium in each of these contexts is crucial. If nonproliferation and arms control experts do not include tritium assessment in their toolbox, they will miss a key material bottleneck in the modernization and expansion of nuclear stockpiles. Likewise, if commercial fusion and its substantial increase of tritium availability arrive without confronting  potential impacts on nuclear weapon infrastructures, policymakers may be caught off guard by destabilizing knock-on effects. Tritium is too important to both nuclear weapon and fusion energy infrastructures to expect that either could develop without affecting the other.

What began with a seed planted nearly seven years ago when Sonja wondered if I was “still interested in tritium” has grown into an international collaborative project. The TMWG will work to foreground tritium science, technology, and policy and provide reliable and valuable analyses. We aim to convince you that tritium matters and that prudent approaches to tritium policies can mitigate nuclear risks and help map the contours of a fusion future.