Plutonium is a transuranic radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized.
Here are several key points regarding plutonium:
- Discovery:
- Plutonium was first produced and isolated in 1940 by a team of scientists led by Glenn T. Seaborg and Edwin McMillan at the University of California, Berkeley, by bombarding uranium-238 with deuterons.
- Isotopes:
- There are several isotopes of plutonium, but plutonium-239 (Pu-239) is the most well-known due to its use in nuclear reactors and nuclear weapons.
- Pu-239 is created in breeder reactors from uranium-238 by neutron capture.
- Radioactivity:
- Plutonium is highly radioactive and can accumulate in bones, which makes it dangerous to handle without proper precautions.
- Applications:
- Nuclear Energy: Plutonium-239 is used as a fuel in nuclear reactors due to its ability to undergo fission, a process in which a nucleus splits into two or more smaller nuclei along with a few neutrons and a large amount of energy.
- Nuclear Weapons: Pu-239 is also used in the production of nuclear weapons due to its fissile nature.
- Space Exploration: The isotope plutonium-238 (Pu-238) has been used as a heat source in radioisotope thermoelectric generators (RTGs) to provide electricity for space missions, including the Voyager, New Horizons, and Mars Curiosity Rover missions.
- Health and Environmental Hazards:
- Due to its high radioactivity, plutonium poses serious health risks upon exposure. It’s especially dangerous if inhaled or ingested as it can remain in the body and irradiate tissues over a long period.
- Additionally, plutonium’s long half-life (the time it takes for half of the radioactive atoms to decay) of over 24,000 years for Pu-239 makes it a significant environmental hazard.
- Production and Disposal:
- Plutonium is artificially produced in breeder nuclear reactors by irradiating uranium-238 with neutrons.
- The disposal and containment of plutonium waste are major challenges due to its long half-life and high radioactivity.
- Nuclear Non-Proliferation:
- Due to its potential use in nuclear weapons, the production and handling of plutonium are tightly controlled under nuclear non-proliferation agreements to prevent the spread of nuclear weapons.
- Historical Context:
- The discovery and subsequent production of plutonium played a significant role in the Manhattan Project, which led to the development of the first atomic bombs during World War II.
Plutonium has both beneficial and destructive potential. Its uses in nuclear energy and space exploration showcase its beneficial side, while its use in nuclear weaponry and the associated health and environmental risks underscore its dangerous aspects. Hence, the handling and control of plutonium are subjects of international policy and security discussions.