Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Plutonium
Summary
Plutonium is a 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, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous.
Plutonium was first synthetically produced and isolated in late 1940 and early 1941, by a deuteron bombardment of uranium-238 in the cyclotron at the University of California, Berkeley. First, neptunium-238 (half-life 2.1 days) was synthesized, which subsequently beta-decayed to form the new element with atomic number 94 and atomic weight 238 (half-life 88 years). Since uranium had been named after the planet Uranus and neptunium after the planet Neptune, element 94 was named after Pluto, which at the time was considered to be a planet as well. Wartime secrecy prevented the University of California team from publishing its discovery until 1948.
Plutonium is the element with the highest atomic number to occur in nature. Trace quantities arise in natural uranium-238 deposits when uranium-238 captures neutrons emitted by decay of other uranium-238 atoms.
Both plutonium-239 and plutonium-241 are fissile, meaning that they can sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors. Plutonium-240 exhibits a high rate of spontaneous fission, raising the neutron flux of any sample containing it. The presence of plutonium-240 limits a plutonium sample's usability for weapons or its quality as reactor fuel, and the percentage of plutonium-240 determines its grade (weapons-grade, fuel-grade, or reactor-grade). Plutonium-238 has a half-life of 87.7 years and emits alpha particles.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related courses (12)
PHYS-443: Physics of nuclear reactors
In this course, one acquires an understanding of the basic neutronics interactions occurring in a nuclear fission reactor as well as the conditions for establishing and controlling a nuclear chain rea
ME-464: Introduction to nuclear engineering
This course is intended to understand the engineering design of nuclear power plants using the basic principles of reactor physics, fluid flow and heat transfer. This course includes the following: Re
PHYS-452: Radiation detection
The course presents the detection of ionizing radiation in the keV and MeV energy ranges. Physical processes of radiation/matter interaction are introduced. All steps of detection are covered, as well
Related publications (75)
Related people (18)
Related units (1)
Related concepts (140)
Atomic bombings of Hiroshima and Nagasaki
On 6 and 9 August 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki. The bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in an armed conflict. Japan surrendered to the Allies on 15 August, six days after the bombing of Nagasaki and the Soviet Union's declaration of war against Japan and invasion of Japanese-occupied Manchuria. The Japanese government signed the instrument of surrender on 2 September, effectively ending the war.
Ion exchange
Ion exchange is a reversible interchange of one kind of ion present in an insoluble solid with another of like charge present in a solution surrounding the solid with the reaction being used especially for softening or making water demineralised, the purification of chemicals and separation of substances. Ion exchange usually describes a process of purification of aqueous solutions using solid polymeric ion-exchange resin. More precisely, the term encompasses a large variety of processes where ions are exchanged between two electrolytes.
Atomic battery
An atomic battery, nuclear battery, radioisotope battery or radioisotope generator is a device which uses energy from the decay of a radioactive isotope to generate electricity. Like nuclear reactors, they generate electricity from nuclear energy, but differ in that they do not use a chain reaction. Although commonly called batteries, they are technically not electrochemical and cannot be charged or recharged.