A nearly forgotten 1938 experiment by physicist Arthur Ruhlig at the University of Michigan likely marked the first observation of deuterium-tritium (DT) fusion, a reaction central to modern fusion energy and national security technologies. Ruhlig hypothesized that DT fusion occurs with very high probability when deuterium and tritium nuclei are brought close together, an insight confirmed nearly a century later by a collaboration between Los Alamos National Laboratory and Duke University. By replicating Ruhlig’s original experiment with modern equipment, the team validated his qualitative conclusion that DT fusion is “exceedingly probable,” although Ruhlig had overestimated the reaction rate. This rediscovery not only restores Ruhlig’s place in fusion history but also connects his work to key Manhattan Project developments and ongoing fusion research efforts such as those at the National Ignition Facility, highlighting how early, overlooked experiments continue to shape the future of fusion energy.
While replicating Ruhlig’s experiment requires specialized equipment like particle accelerators and neutron detectors found only in advanced research labs, you can explore the principles of fusion through educational simulations and demonstrations available online or at science museums. These resources illustrate how isotopes like deuterium and tritium fuse under extreme conditions, helping you understand the fundamental physics behind fusion reactions. For hands-on learning, safe tabletop experiments involving hydrogen isotopes or plasma physics kits can provide insight into nuclear processes on a smaller scale, though direct observation of fusion like Ruhlig’s remains a challenge outside professional facilities.
Tritium and deuterium are isotopes of hydrogen, but they differ greatly in availability and safety. Deuterium is naturally found in small amounts in ordinary water (about 0.015% of hydrogen atoms) and can be extracted relatively easily by processes like electrolysis or distillation of heavy water, which is commercially available for scientific use. In contrast, tritium is radioactive, rare, and not naturally abundant; it is primarily produced in nuclear reactors or specialized facilities by neutron irradiation of lithium or heavy water. Because tritium is radioactive and tightly regulated due to health and safety risks, it is not obtainable by consumers from common materials and cannot be safely or legally produced at home.
Attempting to make tritium yourself would require access to neutron sources or nuclear reactors, which are strictly controlled and unavailable to the public. Moreover, tritium exposure poses significant health hazards, including radiation risks and environmental contamination, making any unauthorized production or handling illegal and dangerous. Therefore, while deuterium can be sourced in small quantities through heavy water suppliers or specialized chemical providers, tritium production and acquisition are restricted to licensed nuclear facilities and are not feasible or safe for consumer-level efforts.
Yes, well. Tokyo Electric Power Company (TEPCO) releases treated water containing tritium from the Fukushima Daiichi plant in batches of about 7,800 cubic meters per discharge, which converts to approximately 2,060,540 U.S. gallons. With roughly seven discharges planned annually, this totals around 14.4 million gallons per year of diluted tritium-containing water released into the Pacific Ocean. When averaged over the entire year, this equates to about 39,450 gallons per day. However, since discharges occur on specific days rather than continuously, the volume released on active discharge days is higher, approximately 121,500 gallons per day. The tritium concentration in the treated water is diluted to about 200 to 500 becquerels per liter, well below regulatory safety limits, and is further diluted with seawater before release. Ongoing monitoring confirms that tritium levels in the ocean and marine life remain far below harmful thresholds, with no detected adverse environmental or health effects to date. A consumer can’t produce or acquire this dangerous substance, but pouring 40 thousand gallons or more of tritium per day into the ocean is totally not a problem, you know because of dilution. That’s great.
Tritium does not vanish with dilution; dilution only reduces its concentration but the radioactive tritium atoms remain present until they decay naturally over time. Because tritium’s half-life is about 12.3 years, it takes roughly that amount of time for half of the tritium in a given sample to decay. After about 5 to 6 half-lives—approximately 60 to 75 years—over 95% of the original tritium will have decayed, significantly reducing its radioactivity. However, until it decays, tritium remains present in the environment, and dilution only lowers its concentration but does not eliminate the radioactive atoms themselves.
While it is theoretically possible to rent a boat in Japan and scoop seawater near Fukushima, the tritium concentration in the ocean around the Fukushima Daiichi plant is extremely low—typically below detection limits of about 3.3 to 6.3 becquerels per liter, far below national and international safety standards. This is due to the treated water being heavily diluted before and after discharge, resulting in tritium levels in seawater around 0.1 to 1.0 Bq/L, which is even lower than typical background levels in some areas. Therefore, while you could physically collect seawater, the tritium present would be at very low concentrations, requiring specialized laboratory equipment and enrichment methods to detect or measure it accurately. Additionally, there are no public restrictions explicitly forbidding collecting seawater offshore in general, but local regulations and safety protocols around the Fukushima site may apply, so permission and compliance with local laws would be necessary.
Well, there goes that idea. I very likely will not be repeating Ruhlig’s fusion experiment.
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[1] https://thebulletin.org/2023/06/exploring-tritiums-danger-a-book-review/
[2] https://www.climate-and-hope.net/electricity-technologies/safety-of-fusion-compared-to-fission
[3] https://www.ntanet.net/understanding-radiation-risks-in-fusion-energy/
[4] https://www.iaea.org/bulletin/safety-in-fusion
[5] https://www.nrc.gov/docs/ML2114/ML21140A435.pdf
[6] https://www.sciencedirect.com/science/article/abs/pii/S0022311510009347
[7] https://nstopenresearch.org/articles/2-72
[8] https://inis.iaea.org/records/agh86-c1f48