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Updated: Dec 10, 2025
12:22
Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films
Published on: November 9, 2015
11.7K
Accounting for Unfissioned Plutonium from the Trinity Atomic Bomb Test.
Harold L Beck1, Steven L Simon2, André Bouville3
1US DOE Environmental Measurements Laboratory (retired).
Health Physics
|September 4, 2020
Summary
The Trinity test dispersed unfissioned plutonium across New Mexico, primarily in the Chupadera Mesa area. Deposition levels were generally lower than subsequent fallout, posing minimal health risks.
Area of Science:
- Environmental Science
- Nuclear Chemistry
- Radiological Health
Background:
- The Trinity test utilized approximately 6 kg of plutonium, with only 15% undergoing fission.
- Unfissioned plutonium was vaporized, cooled, and deposited downwind with fission and activation products.
Purpose of the Study:
- To estimate the total activity and geographical distribution of unfissioned plutonium deposited in New Mexico after the Trinity test.
- To compare Trinity plutonium deposition with fallout from subsequent nuclear tests.
Main Methods:
- Analysis of radiochemical data from post-shot soil samples.
- Modeling of plutonium deposition density using exposure rate data.
- Comparison with historical data from Nevada Test Site and global fallout.
Main Results:
- Approximately 80% of the unfissioned plutonium was deposited within New Mexico, concentrated in the Chupadera Mesa area (30-100 km downwind).
- Plutonium deposition density was a small fraction of later fallout in most of New Mexico.
- A larger fraction of plutonium deposited closer to the site compared to volatile fission products due to its refractory nature.
Conclusions:
- The Trinity test resulted in significant localized plutonium deposition in New Mexico.
- Plutonium deposition from Trinity was distinct from and generally less impactful than subsequent fallout.
- The health risks to the downwind population from Trinity-deposited plutonium were likely insignificant.
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