How does plutonium work

Plutonium is a silvery-gray metal that becomes yellowish when exposed to air. Most plutonium in the environment is in the form of microscopic particles that are the remnants of nuclear weapons testing and nuclear reactor accidents. Because it emits alpha particles, plutonium is most dangerous when inhaled.

When plutonium particles are inhaled, they lodge in the lung tissue. The alpha particles can kill lung cells, which causes scarring of the lungs, leading to further lung disease and cancer. Plutonium can enter the blood stream from the lungs and travel to the kidneys, meaning that the blood and the kidneys will be exposed to alpha particles.

Once plutonium circulates through the body, it concentrates in the bones, liver, and spleen, exposing these organs to alpha particles. Plutonium that is ingested from contaminated food or water does not pose a serious threat to humans because the stomach does not absorb plutonium easily and so it passes out of the body in the feces. Skip directly to site content Skip directly to page options Skip directly to A-Z link. They suggested to a colleague, Glenn Seaborg , that he continue their research on neptunium.

Seaborg and his associates picked up where McMillan and Abelson had left off. They eventually proved that element 94 did exist. The proof came in an experiment they conducted in a particle accelerator at UCB.

A particle accelerator is sometimes called an "atom smasher. The particles then collide with targets, such as gold, copper, or tin. When struck by the particles, the targets break apart, forming new elements and other particles.

Seaborg's team suggested the name plutonium for the new element, in honor of the planet Pluto. The two elements just before plutonium in the periodic table had also been named for planets: uranium for Uranus and neptunium for Neptune.

Glenn Seaborg later went on to find a number of other elements. One of those elements, atomic number , has been named seaborgium in his honor. See transfermium elements in this volume. Plutonium is a silvery-white metal with a melting point of Glowing pellet of plutonium. Scientists now know that very small amounts of plutonium occur in the Earth's crust.

It is formed in ores of uranium. When uranium breaks down, it sometimes forms plutonium in very small quantities. Scientists believe that the abundance of plutonium in the earth is about one quintillionth parts per million.

About 15 isotopes of plutonium are known to exist. All of these isotopes are radioactive. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element's name is the mass number.

The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. The most stable isotopes of plutonium are plutonium and plutonium The half lives of these two isotopes are , years and 82,, years respectively.

The half life of a radioactive element is the time it takes for half of a sample of the element to break down. Consider the isotope plutonium, Historic cardiac pacemaker fueled by radioactive plutonium In , years one half life , only half of a sample prepared today would still be plutonium The rest would have broken down into a new isotope. Plutonium is extracted from natural sources only rarely and only for the purposes of research.

The most important uses of plutonium depend on two of its properties. There are three principal routes by which plutonium can get into human beings who might be exposed to it:.

Ingestion is not a significant hazard, because plutonium passing through the gastro-intestinal tract is poorly absorbed and is expelled from the body before it can do harm.

Contamination of wounds has rarely occurred although thousands of people have worked with plutonium. Their health has been protected by the use of remote handling, protective clothing and extensive health monitoring procedures.

The main threat to humans comes from inhalation. While it is very difficult to create airborne dispersion of a heavy metal like plutonium, certain forms, including the insoluble plutonium oxide, at a particle size less than 10 microns 0. If inhaled, much of the material is immediately exhaled or is expelled by mucous flow from the bronchial system into the gastro-intestinal tract, as with any particulate matter.

Some however will be trapped and readily transferred, first to the blood or lymph system and later to other parts of the body, notably the liver and bones.

It is here that the deposited plutonium's alpha radiation may eventually cause cancer. However, the hazard from Pu is similar to that from any other alpha-emitting radionuclides which might be inhaled.

It is less hazardous than those which are short-lived and hence more radioactive, such as radon daughters, the decay products of radon gas, which albeit in low concentrations are naturally common and widespread in the environment. In the s some 26 workers at US nuclear weapons facilities became contaminated with plutonium.

Intensive health checks of these people have revealed no serious consequence and no fatalities that could be attributed to the exposure. In the s plutonium was injected into and inhaled by some volunteers, without adverse effects. In the s Queen Elizabeth II was visiting Harwell and was handed a lump of plutonium presumably Pu in a plastic bag and invited to feel how warm it was. Plutonium is one among many toxic materials that have to be handled with great care to minimize the associated but well understood risks.

Half-life is the time it takes for a radionuclide to lose half of its own radioactivity. The fissile isotopes can be used as fuel in a nuclear reactor, others are capable of absorbing neutrons and becoming fissile i. Alpha decays are generally accompanied by gamma radiation. The term 'fissionable' applies to isotopes that can be made to undergo fission. If a fissionable isotope only requires neutrons with low kinetic energy to undergo fission, then it is said to 'fissile'.

Thus, all fissile isotopes are fissionable. Pu is fissionable, as it undergoes fission in a fast neutron reactor — but it is not a fissile isotope. It is theoretically possible, but very unlikely, that some UK civil plutonium may have been transferred to the US and used in the US nuclear weapons programme before See also I.

Gurban and M. HV Henderickz, Plutonium: blessing or curse? Plutonium Updated April Over one-third of the energy produced in most nuclear power plants comes from plutonium. It is created in the reactor as a by-product. Plutonium recovered from reprocessing normal reactor fuel is recycled as mixed-oxide fuel MOX. Plutonium has occurred naturally, but except for trace quantities it is not now found in the Earth's crust. There are several tonnes of plutonium in our biosphere, a legacy of atmospheric weapons testing in the s and s.

Plutonium is a vital power source for deep space missions. Plutonium and nuclear power Plutonium is formed in nuclear power reactors from uranium by neutron capture. Reaction in standard UO 2 fuel Like all other heavy elements, plutonium has a number of isotopes, differing in the number of neutrons in the nucleus. All other military data are rough estimates. We have assumed a figure of metric tons of military plutonium for Russia in the and totals.

Recent data form Russia indicate that the figure may be lower, at about metric tons rounded. A cut-away view of the Japanese "Monju" fast breeder reactor.

The two circuits contain sodium coolant with the secondary, non-radioactive loop drawing heat from the primary loop. The December, sodium leak occurred in the secondary circuit.