Plutonium is the heaviest primordial element (see also primordial nuclide), by virtue of its most stable isotope, plutonium-244, whose half-life of about 80 million years is just long enough for the element to be found in trace quantities in nature. Plutonium is also a byproduct of nuclear fission in reactors: Some of the neutrons released by the fission process convert uranium-238 nuclei into plutonium.
The most important isotope of plutonium is plutonium-239, with a half-life of 24,100 years. Plutonium-239 is the isotope most useful for nuclear weapons. Plutonium-239 and 241 are fissile, meaning the nuclei of their atoms can split when bombarded by neutrons, releasing energy, gamma radiation and more neutrons. These neutrons can sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors.
Plutonium-238 has a half-life of 88 years and emits alpha particles. It is a heat source in radioisotope thermoelectric generators, which are used to power some spacecraft. Plutonium-240 has a high rate of spontaneous fission, raising the neutron flux of any sample it is in. The presence of plutonium-240 limits a sample's usability for weapons or reactor fuel, and determines its grade. Plutonium isotopes are expensive and inconvenient to separate, so particular isotopes are usually manufactured in specialized reactors.
Plutonium was first synthesized in 1940 by a team led by Glenn T. Seaborg and Edwin McMillan at the University of California, Berkeley laboratory by bombarding uranium-238 with deuterons. Trace amounts of plutonium were subsequently discovered in nature. Producing plutonium in useful quantities for the first time was a major part of the Manhattan Project during World War II, which developed the first atomic bombs. The first nuclear test, "Trinity" (July 1945), and the second atomic bomb used to destroy a city (Nagasaki, Japan, in August 1945), "Fat Man", both had cores of plutonium-239. Human radiation experiments studying plutonium were conducted without informed consent, and a number of criticality accidents, some lethal, occurred during and after the war. Disposal of plutonium waste from nuclear power plants and dismantled nuclear weapons built during the Cold War is a nuclear-proliferation and environmental concern. Other sources of plutonium in the environment are fallout from numerous above-ground nuclear tests (now banned).
Alpha decay, the release of a high-energy helium nucleus, is the most common form of radioactive decay for plutonium. A 5 kg mass of 239Pu contains about 12.5 × 1024 atoms. With a half-life of 24,100 years, about 11.5 × 1012 of its atoms decay each second by emitting a 5.157 MeV alpha particle. This amounts to 9.68 watts of power. Heat produced by the deceleration of these alpha particles makes it warm to the touch.
Resistivity is a measure of how strongly a material opposes the flow of electric current. The resistivity of plutonium at room temperature is very high for a metal, and it gets even higher with lower temperatures, which is unusual for metals. This trend continues down to 100 K, below which resistivity rapidly decreases for fresh samples. Resistivity then begins to increase with time at around 20 K due to radiation damage, with the rate dictated by the isotopic composition of the sample.
Because of self-irradiation, a sample of plutonium fatigues throughout its crystal structure, meaning the ordered arrangement of its atoms becomes disrupted by radiation with time. Self-irradiation can also lead to annealing which counteracts some of the fatigue effects as temperature increases above 100 K.
Unlike most materials, plutonium ''increases'' in density when it melts, by 2.5%, but the liquid metal exhibits a linear decrease in density with temperature. Near the melting point, the liquid plutonium has also very high viscosity and surface tension as compared to other metals.
The presence of these many allotropes makes machining plutonium very difficult, as it changes state very readily. For example, the α form exists at room temperature in unalloyed plutonium. It has machining characteristics similar to cast iron but changes to the plastic and malleable β form (''beta'') at slightly higher temperatures. The reasons for the complicated phase diagram are not entirely understood. The α form has a low-symmetry monoclinic structure, hence its brittleness, strength, compressibility, and poor conductivity.
Plutonium in the δ form normally exists in the 310 °C to 452 °C range but is stable at room temperature when alloyed with a small percentage of gallium, aluminium, or cerium, enhancing workability and allowing it to be welded. The delta form has more typical metallic character, and is roughly as strong and malleable as aluminium. In fission weapons, the explosive shock waves used to compress a plutonium core will also cause a transition from the usual delta phase plutonium to the denser alpha form, significantly helping to achieve supercriticality. The ε phase, the highest temperature solid allotrope, exhibits anomalously high atomic self-diffusion compared to other elements.
Plutonium is an element in which the 5f electrons are the transition border between delocalized and localized; it is therefore considered one of the most complex elements. It is a radioactive actinide metal whose isotope, plutonium-239, is one of the three primary fissile isotopes (uranium-233 and uranium-235 ); plutonium-241 is also highly fissile. To be considered fissile, an isotope's atomic nucleus must be able to break apart or fission when struck by a slow moving neutron, and to release enough additional neutrons in the process to sustain the nuclear chain reaction by splitting further nuclei.
Plutonium-239 has a multiplication factor (k) larger than one, which means that if the metal is present in sufficient mass and with an appropriate geometry (e.g., a compressed sphere), it can form a critical mass. During fission, a fraction of the binding energy, which holds a nucleus together, is released as a large amount of electromagnetic and kinetic energy (much of the latter being quickly converted to thermal energy). Fission of a kilogram of plutonium-239 can produce an explosion equivalent to 21,000 tons of TNT. It is this energy that makes plutonium-239 useful in nuclear weapons and reactors.
The presence of the isotope plutonium-240 in a sample limits its nuclear bomb potential, as plutonium-240 has a relatively high spontaneous fission rate (~440 fissions per second per gram—over 1,000 neutrons per second per gram), raising the background neutron levels and thus increasing the risk of predetonation. Plutonium is identified as either weapons-grade, fuel grade, or power reactor grade based on the percentage of plutonium-240 that it contains. Weapons-grade plutonium contains less than 7% plutonium-240. Fuel grade plutonium contains from 7% to less than 19%, and power reactor grade contains 19% or more plutonium-240. Supergrade plutonium, with less than 4% of plutonium-240, is used in U.S. Navy weapons stored in proximity to ship and submarine crews, due to its lower radioactivity. The isotope plutonium-238 is not fissile but can undergo nuclear fission easily with fast neutrons as well as alpha decay.
The isotopes of plutonium range in mass number from 228 to 247. The primary decay modes of isotopes with mass numbers lower than the most stable isotope, plutonium-244, are spontaneous fission and α emission, mostly forming uranium (92 protons) and neptunium (93 protons) isotopes as decay products (neglecting the wide range of daughter nuclei created by fission processes). The primary decay mode for isotopes with mass numbers higher than plutonium-244 is β emission, mostly forming americium (95 protons) isotopes as decay products. Plutonium-241 is the parent isotope of the neptunium decay series, decaying to americium-241 via β or electron emission.
Plutonium-238 and 239 are the most widely synthesized isotopes. Plutonium-239 is synthesized via the following reaction using uranium (U) and neutrons (n) via beta decay (β−) with neptunium (Np) as an intermediate:
:
Neutrons from the fission of uranium-235 are captured by uranium-238 nuclei to form uranium-239; a beta decay converts a neutron into a proton to form Np-239 (half-life 2.36 days) and another beta decay forms plutonium-239. Workers on the Tube Alloys project had predicted this reaction theoretically in 1940.
Plutonium-238 is synthesized by bombarding uranium-238 with deuterons (D, the nuclei of heavy hydrogen) in the following reaction:
:
In this process, a deuteron hitting uranium-238 produces two neutrons and neptunium-238, which spontaneously decays by emitting negative beta particles to form plutonium-238.
+ Decay heat of plutonium isotopes | ! Isotope !! Decay mode !! Half-life (years) !! Decay heat (W/kg) !! Spontaneous fission neutrons (1/(g·s)) !! Comment | ||||
plutonium-238>Pu-238 | 87.74 | 560 | 2600 | Very high decay heat. Even in small amounts can cause significant self-heating. Used on its own in radioisotope thermoelectric generators. | |
plutonium-239>Pu-239 | 24100 | 1.9 | 0.022 | The principal fissile isotope in use. | |
plutonium-240>Pu-240 | 6560 | 6.8 | 910 | The principal impurity of the Pu-239 isotope. The plutonium grade is usually listed as percentage of Pu-240. High spontaneous fission hinders use in nuclear weapons. | |
plutonium-241>Pu-241 | 14.4 | 4.2 | 0.049 | Decays to americium-241; its buildup presents a radiation hazard in older samples. | |
plutonium-242>Pu-242 | 376000 | 0.1 | 1700 |
Americium-241, the decay product of plutonium-241, has half-life of 430 years, 1.2 spontaneous fissions per gram per second, and decay heat of 114 watts per kilogram. As its decay produces highly penetrative gamma rays, its presence in plutonium, determined by the original concentration of plutonium-241 and the sample age, increases the radiation exposure of surrounding structures and personnel.
The color shown by plutonium solutions depends on both the oxidation state and the nature of the acid anion. It is the acid anion that influences the degree of complexing—how atoms connect to a central atom—of the plutonium species.
Metallic plutonium is produced by reacting plutonium tetrafluoride with barium, calcium or lithium at 1200 °C. It is attacked by acids, oxygen, and steam but not by alkalis and dissolves easily in concentrated hydrochloric, hydroiodic and perchloric acids. Molten metal must be kept in a vacuum or an inert atmosphere to avoid reaction with air. At 135 °C the metal will ignite in air and will explode if placed in carbon tetrachloride.
Plutonium is a reactive metal. In moist air or moist argon, the metal oxidizes rapidly, producing a mixture of oxides and hydrides. If the metal is exposed long enough to a limited amount of water vapor, a powdery surface coating of PuO2 is formed. Also formed is plutonium hydride but an excess of water vapor forms only PuO2.
With this coating, the metal is pyrophoric, meaning it can ignite spontaneously, so plutonium metal is usually handled in an inert, dry atmosphere of nitrogen or argon. Oxygen retards the effects of moisture and acts as a passivating agent.
Plutonium shows enormous, and reversible, reaction rates with pure hydrogen, forming plutonium hydride. It also reacts readily with oxygen, forming PuO and PuO2 as well as intermediate oxides; plutonium oxide fills 40% more volume than plutonium metal. It reacts with the halogens, giving rise to compounds such as PuX3 where X can be F, Cl, Br or I; PuF4 is also seen. The following oxyhalides are observed: PuOCl, PuOBr and PuOI. It will react with carbon to form PuC, nitrogen to form PuN and silicon to form PuSi2.
Crucibles used to contain plutonium need to be able to withstand its strongly reducing properties. Refractory metals such as tantalum and tungsten along with the more stable oxides, borides, carbides, nitrides and silicides can tolerate this. Melting in an electric arc furnace can be used to produce small ingots of the metal without the need for a crucible.
Cerium is used as a chemical simulant of plutonium for development of containment, extraction, and other technologies.
Plutonium alloys can be produced by adding a metal to molten plutonium. If the alloying metal is sufficiently reductive, plutonium can be added in the form of oxides or halides. The δ phase plutonium-gallium and plutonium-aluminium alloys are produced by adding plutonium(III) fluoride to molten gallium or aluminium, which has the advantage of avoiding dealing directly with the highly reactive plutonium metal.
Plutonium-gallium is used for stabilizing the δ phase of plutonium, avoiding the α-phase and α-δ related issues. Its main use is in pits of implosion nuclear weapons. Plutonium-aluminium is an alternative to the Pu-Ga alloy. It was the original element considered for δ phase stabilization, but its tendency to react with the alpha particles and release neutrons reduces its usability for nuclear weapon pits. Plutonium-aluminium alloy can be also used as a component of nuclear fuel. Plutonium-gallium-cobalt alloy (PuCoGa5) is an unconventional superconductor, showing superconductivity below 18.5 kelvin, an order of magnitude higher than the highest between heavy fermion systems, and has large critical current. Plutonium-zirconium alloy can be used as nuclear fuel. Plutonium-cerium and plutonium-cerium-cobalt alloys are used as nuclear fuels. Plutonium-uranium, with about 15–30 mol.% plutonium, can be used as a nuclear fuel for fast breeder reactors. Its pyrophoric nature and high susceptibility to corrosion to the point of self-igniting or disintegrating after exposure to air require alloying with other components. Addition of aluminium, carbon or copper did not improve disintegration rates markedly, zirconium and iron alloys have better corrosion resistance but they disintegrate in several months in air as well. Addition of titanium and/or zirconium significantly increases the melting point of the alloy. Plutonium-uranium-titanium and plutonium-uranium-zirconium were investigated for use as nuclear fuels. The addition of the third element increases corrosion resistance, reduces flammability, and improves ductility, fabricability, strength, and thermal expansion. Plutonium-uranium-molybdenum has the best corrosion resistance, forming a protective film of oxides, but titanium and zirconium are preferred for physics reasons. Thorium-uranium-plutonium was investigated as a nuclear fuel for fast breeder reactors.
Since the relatively long-lived isotope plutonium-240 occurs in the decay chain of plutonium-244 it should also be present, albeit 10,000 times rarer still. Finally, exceedingly small amounts of plutonium-238, attributed to the incredibly rare double beta decay of uranium-238, have been found in natural uranium samples.
Minute traces of plutonium are usually found in the human body due to the 550 atmospheric and underwater nuclear tests that have been carried out, and to a small number of major nuclear accidents. Most atmospheric and underwater nuclear testing was stopped by the Limited Test Ban Treaty in 1963, which was signed and ratified by the United States, the United Kingdom, the Soviet Union, and other nations. Continued atmospheric nuclear weapons testing since 1963 by non-treaty nations included those by China (atomic bomb test above the Gobi Desert in 1964, hydrogen bomb test in 1967, and follow-on tests), and France (tests as recently as the 1980s).
Because it is purposely manufactured for nuclear weapons and nuclear reactors, plutonium-239 is the most abundant isotope of plutonium by far.
It is also hypothetically possible for minute quantities of plutonium to be produced by the natural bombardment of uranium ores with cosmic rays.
Plutonium (specifically, plutonium-238) was first produced and isolated on December 14, 1940, and chemically identified on February 23, 1941, by Dr. Glenn T. Seaborg, Edwin M. McMillan, J. W. Kennedy, and A. C. Wahl by deuteron bombardment of uranium in the cyclotron at the University of California, Berkeley. In the 1940 experiment, neptunium-238 was created directly by the bombardment but decayed by beta emission two days later, which indicated the formation of element 94.
A paper documenting the discovery was prepared by the team and sent to the journal ''Physical Review'' in March 1941. The paper was withdrawn before publication after the discovery that an isotope of the new element (plutonium-239) could undergo nuclear fission in a way that might be useful in an atomic bomb. Publication was delayed until a year after the end of World War II due to security concerns.
Edwin McMillan had recently named the first transuranium element after the planet Neptune and suggested that element 94, being the next element in the series, be named for what was then considered the next planet, Pluto. Seaborg originally considered the name "plutium", but later thought that it did not sound as good as "plutonium." He chose the letters "Pu" as a joke, which passed without notice into the periodic table. Alternative names considered by Seaborg and others were "ultimium" or "extremium" because of the erroneous belief that they had found the last possible element on the periodic table.
In November 1943 some plutonium trifluoride was reduced to create the first sample of plutonium metal: a few micrograms of metallic beads. Enough plutonium was produced to make it the first synthetically made element to be visible with the unaided eye.
The nuclear properties of plutonium-239 were also studied; researchers found that when it is hit by a neutron it breaks apart (fissions) by releasing more neutrons and energy. These neutrons can hit other atoms of plutonium-239 and so on in an exponentially fast chain reaction. This can result in an explosion large enough to destroy a city if enough of the isotope is concentrated to form a critical mass.
The first production reactor that made plutonium-239 was the X-10 Graphite Reactor. It went online in 1943 and was built at a facility in Oak Ridge that later became the Oak Ridge National Laboratory.
On April 5, 1944, Emilio Segrè at Los Alamos received the first sample of reactor-produced plutonium from Oak Ridge. Within ten days, he discovered that reactor-bred plutonium had a higher concentration of the isotope plutonium-240 than cyclotron-produced plutonium. Plutonium-240 has a high spontaneous fission rate, raising the overall background neutron level of the plutonium sample. The original gun-type plutonium weapon, code-named "Thin Man", had to be abandoned as a result—the increased number of spontaneous neutrons meant that nuclear pre-detonation (a fizzle) would be likely.
The entire plutonium weapon design effort at Los Alamos was soon changed to the more complicated implosion device, code-named "Fat Man." With an implosion weapon, a solid (or, in later designs, hollow) sphere of plutonium is compressed to a high density with explosive lenses—a technically more daunting task than the simple gun-type design, but necessary in order to use plutonium for weapons purposes. (Enriched uranium, by contrast, can be used with either method.)
Construction of the Hanford B Reactor, the first industrial-sized nuclear reactor for the purposes of material production, was completed in March 1945. B Reactor produced the fissile material for the plutonium weapons used during World War II. B, D and F were the initial reactors built at Hanford, and six additional plutonium-producing reactors were built later at the site.
In 2004, a safe was discovered during excavations of a burial trench at the Hanford nuclear site. Inside the safe were various items, including a large glass bottle containing a whitish slurry which was subsequently identified as the oldest sample of weapons-grade plutonium known to exist. Isotope analysis by Pacific Northwest National Laboratory indicated that the plutonium in the bottle was manufactured in the X-10 reactor at Oak Ridge during 1944.
The first atomic bomb test, codenamed "Trinity" and detonated on July 16, 1945, near Alamogordo, New Mexico, used plutonium as its fissile material. The implosion design of "the Gadget", as the Trinity device was code-named, used conventional explosive lenses to compress a sphere of plutonium into a supercritical mass, which was simultaneously showered with neutrons from the "Urchin", an initiator made of polonium and beryllium (neutron source: (α, n) reaction). Together, these ensured a runaway chain reaction and explosion. The overall weapon weighed over 4 tonnes, although it used just 6.2 kg of plutonium in its core. About 20% of the plutonium used in the Trinity weapon underwent fission, resulting in an explosion with an energy equivalent to approximately 20,000 tons of TNT.
An identical design was used in the "Fat Man" atomic bomb dropped on Nagasaki, Japan, on August 9, 1945, killing 70,000 people and wounding another 100,000. The "Little Boy" bomb dropped on Hiroshima three days earlier used uranium-235, not plutonium. Japan capitulated on August 15 to General Douglas MacArthur. Only after the announcement of the first atomic bombs was the existence of plutonium made public.
Since the end of the Cold War, these stockpiles have become a focus of nuclear proliferation concerns. In the U.S., some plutonium extracted from dismantled nuclear weapons is melted to form glass logs of plutonium oxide that weigh two tonnes. The glass is made of borosilicates mixed with cadmium and gadolinium. These logs are planned to be encased in stainless steel and stored as much as 4 km underground in bore holes that will be back-filled with concrete. As of 2008, the only facility in the U.S. that is scheduled to store plutonium in this way is the Yucca Mountain nuclear waste repository, which is about north-east of Las Vegas, Nevada. Local and state opposition to this plan has delayed efforts to store nuclear waste at Yucca Mountain. In March 2010, the Department of Energy withdrew its license application for the Yucca Mountain repository "with predjudice" and eliminated funding for the Office of Civilian Radioactive Waste Management, which had managed the Yucca Mountain site for 25 years.
In the case of human subjects, this involved injecting solutions containing (typically) five micrograms of plutonium into hospital patients thought to be either terminally ill, or to have a life expectancy of less than ten years either due to age or chronic disease condition. This was reduced to one microgram in July 1945 after animal studies found that the way plutonium distributed itself in bones was more dangerous than radium.
Eighteen human test subjects were injected with plutonium without informed consent. The tests were used to create diagnostic tools to determine the uptake of plutonium in the body in order to develop safety standards for working with plutonium.
The episode is now considered to be a serious breach of medical ethics and of the Hippocratic Oath. More sympathetic commentators have noted that while it was definitely a breach in trust and ethics, "the effects of the plutonium injections were not as damaging to the subjects as the early news stories painted, nor were they so inconsequential as many scientists, then and now, believe."
The "Fat Man"-type plutonium bombs produced during the Manhattan Project used explosive compression of plutonium to obtain significantly higher densities than normal, combined with a central neutron source to begin the reaction and increase efficiency. Thus only 6.2 kg of plutonium was needed for an explosive yield equivalent to 20 kilotons of TNT. (See also Nuclear weapon design.) Hypothetically, as little as 4 kg of plutonium—and maybe even less—could be used to make a single atomic bomb using very sophisticated assembly designs.
Spent nuclear fuel from normal light water reactors contains Plutonium, but it is a mixture of Plutonium-242, 240, 239 and 238. The mixture is not sufficiently enriched for efficient nuclear weapons, but can be used once as MOX fuel. Accidental neutron capture causes the amount of Plutonium-242 and 240 to grow each time the Plutonium is irradiated in a reactor with low-speed "thermal" neutrons, so that after the second cycle, the Plutonium can only be consumed by fast neutron reactors. If fast neutron reactors are not available (the normal case), excess Plutonium is usually discarded, and forms the longest-lived component of nuclear waste. The desire to consume this Plutonium and other transuranic fuels and reduce the radiotoxicity of the waste is the usual reason nuclear engineers give to make fast neutron reactors.
The most common chemical process, PUREX (''P''lutonium–''UR''anium ''EX''traction) reprocesses spent nuclear fuel to extract plutonium and uranium which can be used to form a mixed oxide "MOX fuel" for reuse in nuclear reactors. Weapons grade plutonium can be added to the fuel mix. MOX fuel is used in light water reactors and consists of 60 kg of plutonium per tonne of fuel; after four years, three-quarters of the plutonium is burned (turned into other elements). Breeder reactors are specifically designed to create more fissionable material than they consume.
MOX fuel has been in use since the 1980s and is widely used in Europe. In September 2000, the United States and the Russian Federation signed a Plutonium Management and Disposition Agreement by which each agreed to dispose of 34 tonnes of weapon grade plutonium. The U.S. Department of Energy plans to dispose of 34 tonnes of weapon grade plutonium in the United States before the end of 2019 by converting the plutonium to a MOX fuel to be used in commercial nuclear power reactors.
MOX fuel improves total burnup. A fuel rod is reprocessed after three years of use to remove waste products, which by then account for 3% of the total weight of the rods. Any uranium or plutonium isotopes produced during those three years are left and the rod goes back into production. The presence of up to 1% gallium per mass in weapon grade plutonium alloy has the potential to interfere with long-term operation of a light water reactor.
Plutonium recovered from spent reactor fuel poses a less significant proliferation hazard, because of excessive contamination with non-fissile plutonium-240 and plutonium-242. Separation of the isotopes is not feasible. A dedicated reactor operating on very low burnup is generally required to produce material suitable for use in efficient nuclear weapons. While 'weapons-grade' plutonium is defined to contain at least 92% plutonium-239, the United States have managed to detonate an under-20Kt device using plutonium believed to contain only about 85% plutonium-239, so called 'fuel-grade' plutonium. The 'reactor grade' plutonium produced by a regular LWR burnup cycle typically contains less than 60% Pu-239, with up to 30% parasitic Pu-240/Pu-242, and 10-15% fissile Pu-241. It's unknown if a device using plutonium obtained from reprocessed civil nuclear waste can be detonated, however such a device could hypothetically fizzle and spread radioactive materials over a large urban area. The IAEA conservatively classifies plutonium of all isotopic vectors as "direct-use" material, that is, "nuclear material that can be used for the manufacture of nuclear explosives components without transmutation or further enrichment".
241Am has recently been suggested for use as a denaturing agent in plutonium reactor fuel rods to further limit its proliferation potential.
These characteristics make it well-suited for electrical power generation for devices which must function without direct maintenance for timescales approximating a human lifetime. It is therefore used in radioisotope thermoelectric generators and radioisotope heater units such as those in the Cassini, Voyager and New Horizons space probes.
The twin Voyager spacecraft were launched in 1977 with each containing a 500 watt plutonium power source. Over 30 years later each source is still producing about 300 watts which allows limited operation of each spacecraft. Earlier versions of the same technology powered the ALSEP and EASEP systems including seismic experiments on the Apollo 14 Moon mission.
Plutonium-238 has also been used successfully to power artificial heart pacemakers, to reduce the risk of repeated surgery. It has been largely replaced by lithium-based primary cells, but as of 2003 there were somewhere between 50 and 100 plutonium-powered pacemakers still implanted and functioning in living patients. Plutonium-238 was studied as way to provide supplemental heat to scuba diving. Plutonium-238 mixed with beryllium is used to generate neutrons for research purposes.
During the decay of plutonium, three types of radiation are released—alpha, beta, and gamma. Alpha radiation can travel only a short distance and cannot travel through the outer, dead layer of human skin. Beta radiation can penetrate human skin, but cannot go all the way through the body. Gamma radiation can go all the way through the body. Alpha, beta, and gamma radiation are all forms of ionizing radiation. Either acute or longer-term exposure carries a danger of unfavorable health outcomes including radiation sickness, cancer, and death. The danger increases with the amount of exposure.
Even though alpha radiation cannot penetrate the skin, ingested or inhaled plutonium does irradiate internal organs. The skeleton, where plutonium is absorbed, and the liver, where it collects and becomes concentrated, are at risk. Plutonium is not absorbed into the body efficiently when ingested; only 0.04% of plutonium oxide is absorbed after ingestion. Plutonium absorbed by the body is excreted very slowly, with a biological half-life of 200 years. Plutonium passes only slowly through cell membranes and intestinal boundaries, so absorption by ingestion and incorporation into bone structure proceeds very slowly.
Plutonium is more dangerous when inhaled than when ingested. The risk of lung cancer increases once the total radiation dose equivalent of inhaled plutonium exceeds 400 mSv. The U.S. Department of Energy estimates that the lifetime cancer risk from inhaling 5,000 plutonium particles, each about 3 microns wide, to be 1% over the background U.S. average. Ingestion or inhalation of large amounts may cause acute radiation poisoning and death; no human is known to have died because of inhaling or ingesting plutonium, and many people have measurable amounts of plutonium in their bodies.
The "hot particle" theory in which a particle of plutonium dust radiates a localized spot of lung tissue has been tested and found false—such particles are more mobile than originally thought and toxicity is not measurably increased due to particulate form.
However, when inhaled, plutonium can pass into the bloodstream. Once in the bloodstream, plutonium moves throughout the body and into the bones, liver, or other body organs. Plutonium that reaches body organs generally stays in the body for decades and continues to expose the surrounding tissue to radiation and thus may cause cancer.
A commonly cited quote by Ralph Nader, states that a pound of plutonium dust spread into the atmosphere would be enough to kill 8 billion people. However, the math shows that one pound of plutonium could kill no more than 2 million people by inhalation. This makes the toxicity of plutonium roughly equivalent with that of nerve gas.
Several populations of people who have been exposed to plutonium dust (e.g. people living down-wind of Nevada test sites, Hiroshima survivors, nuclear facility workers, and "terminally ill" patients injected with Pu in 1945–46 to study Pu metabolism) have been carefully followed and analyzed. These studies generally do not show especially high plutonium toxicity or plutonium-induced cancer results. "There were about 25 workers from Los Alamos National Laboratory who inhaled a considerable amount of plutonium dust during the 1940's; according to the hot-particle theory, each of them has a 99.5% chance of being dead from lung cancer by now, but there has not been a single lung cancer among them."
Plutonium has a metallic taste.
Criticality accidents have occurred in the past, some of them with lethal consequences. Careless handling of tungsten carbide bricks around a 6.2 kg plutonium sphere resulted in a fatal dose of radiation at Los Alamos on August 21, 1945, when scientist Harry K. Daghlian, Jr. received a dose estimated to be 5.1 Sievert (510 rems) and died 28 days later. Nine months later, another Los Alamos scientist, Louis Slotin, died from a similar accident involving a beryllium reflector and the same plutonium core (the so-called "demon core") that had previously claimed the life of Daghlian. These incidents were fictionalized in the 1989 film ''Fat Man and Little Boy''.
In December 1958, during a process of purifying plutonium at Los Alamos, a critical mass was formed in a mixing vessel, which resulted in the death of a chemical operator named Cecil Kelley. Other nuclear accidents have occurred in the Soviet Union, Japan, the United States and many other countries.
Category:Actinides Category:Carcinogens Category:Chemical elements Category:Nuclear materials * Category:Synthetic elements
ar:بلوتونيوم az:Plutonium bn:প্লুটোনিয়াম be:Плутоній bs:Plutonijum bg:Плутоний ca:Plutoni cv:Плутони cs:Plutonium co:Plutoniu cy:Plwtoniwm da:Plutonium de:Plutonium et:Plutoonium el:Πλουτώνιο es:Plutonio eo:Plutonio eu:Plutonio fa:پلوتونیم hif:Plutonium fr:Plutonium fy:Plutoanium ga:Plútóiniam gv:Plutonium gl:Plutonio hak:Pu xal:Плутониум ko:플루토늄 hy:Պլուտոնիում hi:प्लूटोनियम hr:Plutonij io:Plutonio id:Plutonium it:Plutonio he:פלוטוניום kn:ಪ್ಲುಟೋನಿಯಮ್ kv:Плутоний ht:Plitonyòm la:Plutonium lv:Plutonijs lb:Plutonium lt:Plutonis lij:Plutonnio jbo:jinmrplutoni hu:Plutónium mk:Плутониум ml:പ്ലൂട്ടോണിയം mr:प्लुटोनियम ms:Plutonium mn:Плутони my:ပလူတိုနီယမ် nah:Mictlāntēuctepoztli mrj:Плутоний nl:Plutonium ja:プルトニウム no:Plutonium nn:Plutonium pnb:پلوٹونیم nds:Plutonium pl:Pluton (pierwiastek) pt:Plutônio ro:Plutoniu qu:Plutonyu ru:Плутоний sah:Плутониум stq:Plutonium scn:Plutoniu simple:Plutonium sk:Plutónium sl:Plutonij sr:Плутонијум sh:Plutonijum fi:Plutonium sv:Plutonium tl:Plutonyo ta:புளுடோனியம் th:พลูโทเนียม tr:Plütonyum uk:Плутоній ur:پلوٹونیئم ug:پلوتونىي vi:Plutoni war:Plutonyo yo:Plutonium zh-yue:鈽 zh:钚This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
In the early 1960s, Waldman became a student of Buddhism. In the 1970s, along with Allen Ginsberg, she began to study with the Tibetan Chogyam Trungpa Rinpoche. In 1974, with Trungpa, Ginsberg, and others, Waldman founded the Jack Kerouac School of Disembodied Poetics at the Naropa Institute in Boulder, Colorado (now Naropa University), where she remains a Distinguished Professor of Poetics and the Director of Naropa's famous Summer Writing Program.
In 1976, Waldman and Ginsberg were featured in Bob Dylan's film, ''Renaldo and Clara.'' They worked on the film while traveling through New England and Canada with the Rolling Thunder Revue, a concert tour that made impromptu stops, entertaining enthusiastic crowds with poetry and music. Waldman, Ginsberg, and Dylan were joined on these caravans by musicians such as Joan Baez, Joni Mitchell, Eric Anderson, and Joe Cocker. Waldman reveled in the experience, and she often thought of recreating the poetry caravan.
Waldman married Reed Bye in 1980, and their son, Edwin Ambrose Bye was born on October 21, 1980. The birth of her son proved to be an "inspiring turning point" for Waldman, and she became passionately interested in and deeply committed to the survival of the planet. Her child, she said, became her teacher. He inspired her poem, "Number Song" in which she writes, "I sing of my son." Waldman and Ambrose Bye occasionally perform poetry together, and the two have created a YouTube channel entitled ''Fast Speaking Music'' that features music and poetry videos.
Waldman has been a fervent activist for social change. In the 1970s, she was involved with the Rocky Flats Truth Force, an organization opposed to the Rocky Flats nuclear weapons facility ten miles to the south of Boulder, Colorado. With Daniel Ellsberg and Allen Ginsberg, she was arrested for protesting outside of the site. She has been a vocal proponent for feminist, environmental, and human rights causes, an active participant in Poets Against the War, and she has helped organize protests in New York and Washington, D.C.
Although her work is sometimes connected to the Beat Generation, Waldman has never been, strictly speaking, a "Beat" poet. Her work, like the work of her contemporaries in the 1970s New York milieu of which she was a vital part—writers like Alice Notley and Bernadette Mayer, to name only two—is more diverse in its influences and ambitions. Waldman is particularly interested in the performance of her poetry: she considers performance a "ritualized event in time," and she expresses the energy of her poetry through exuberant breathing, chanting, singing, and movement. Waldman credits her poem, ''Fast Speaking Woman'', as the seminal work that galvanized her idea of poetry as performance. Ginsberg, Kenneth Koch, Lawrence Ferlinghetti - all encouraged her to continue to perform her poetry.
Waldman has published more than forty books of poetry [see bibliography below]. Her work has been widely anthologized, and her poems have been translated into French, Italian, German, Turkish, Spanish, and Chinese. Waldman is also the editor of several volumes relating to modern, postmodern, and contemporary poetry. Over the course of her career, Waldman has also been a tireless collaborator, producing works with artists Elizabeth Murray, Richard Tuttle, George Schneeman, Donna Dennis, Pat Steir; musicians Don Cherry and Steve Lacy; dancer Douglas Dunn; filmmaker and husband Ed Bowes; and her son, musician/composer Ambrose Bye.
Waldman has been a Fellow at the Emily Harvey Foundation (Winter 2007) and the Bellagio Center in Italy (Spring 2006). She has also held residencies at the Christian Woman’s University of Tokyo (Fall 2004); the Schule für Dichtung in Vienna (where she has also served as Curriculum Director in 1989); the Institute of American Indian Arts in Santa Fe, New Mexico; and the Stevens Institute of Technology in Hoboken, New Jersey (1984). She has served as an advisor to the Prazska Skola Projekt in Prague, the Study Abroad on the Bowery (since 2004), and has been a faculty member in the New England College Low Residency MFA Program (since 2003). She is the recipient of grants from the National Endowment for the Arts (NEA) and the Contemporary Artists Foundation, among others. With writer and scholar Ammiel Alcalay, she founded the Poetry is News Coalition in 2002.
Her archive of historical, literary, art, tape, and extensive correspondence materials (including many prominent literary correspondents, such as: William S. Burroughs, Robert Creeley, Diane Di Prima, Lawrence Ferlinghetti, Allen Ginsberg, and Ken Kesey) resides at the University of Michigan's Hatcher Graduate Library in Ann Arbor, Michigan. A 55-minute film titled “Anne Waldman: Makeup on Empty Space,” a film by poet Jim Cohn, documents the opening of the Anne Waldman Collection at the University of Michigan.
Poetry Collaborations
Audio Recordings
Film and Video
Editor
Anthologies
Category:1945 births Category:Living people Category:Modernist women writers Category:American poets Category:Beat Generation writers Category:People from Boulder, Colorado Category:People from Cumberland County, New Jersey Category:People from New York City Category:Bennington College alumni
da:Anne Waldman fr:Anne Waldman sv:Anne WaldmanThis text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
The World News (WN) Network, has created this privacy statement in order to demonstrate our firm commitment to user privacy. The following discloses our information gathering and dissemination practices for wn.com, as well as e-mail newsletters.
We do not collect personally identifiable information about you, except when you provide it to us. For example, if you submit an inquiry to us or sign up for our newsletter, you may be asked to provide certain information such as your contact details (name, e-mail address, mailing address, etc.).
When you submit your personally identifiable information through wn.com, you are giving your consent to the collection, use and disclosure of your personal information as set forth in this Privacy Policy. If you would prefer that we not collect any personally identifiable information from you, please do not provide us with any such information. We will not sell or rent your personally identifiable information to third parties without your consent, except as otherwise disclosed in this Privacy Policy.
Except as otherwise disclosed in this Privacy Policy, we will use the information you provide us only for the purpose of responding to your inquiry or in connection with the service for which you provided such information. We may forward your contact information and inquiry to our affiliates and other divisions of our company that we feel can best address your inquiry or provide you with the requested service. We may also use the information you provide in aggregate form for internal business purposes, such as generating statistics and developing marketing plans. We may share or transfer such non-personally identifiable information with or to our affiliates, licensees, agents and partners.
We may retain other companies and individuals to perform functions on our behalf. Such third parties may be provided with access to personally identifiable information needed to perform their functions, but may not use such information for any other purpose.
In addition, we may disclose any information, including personally identifiable information, we deem necessary, in our sole discretion, to comply with any applicable law, regulation, legal proceeding or governmental request.
We do not want you to receive unwanted e-mail from us. We try to make it easy to opt-out of any service you have asked to receive. If you sign-up to our e-mail newsletters we do not sell, exchange or give your e-mail address to a third party.
E-mail addresses are collected via the wn.com web site. Users have to physically opt-in to receive the wn.com newsletter and a verification e-mail is sent. wn.com is clearly and conspicuously named at the point of
collection.If you no longer wish to receive our newsletter and promotional communications, you may opt-out of receiving them by following the instructions included in each newsletter or communication or by e-mailing us at michaelw(at)wn.com
The security of your personal information is important to us. We follow generally accepted industry standards to protect the personal information submitted to us, both during registration and once we receive it. No method of transmission over the Internet, or method of electronic storage, is 100 percent secure, however. Therefore, though we strive to use commercially acceptable means to protect your personal information, we cannot guarantee its absolute security.
If we decide to change our e-mail practices, we will post those changes to this privacy statement, the homepage, and other places we think appropriate so that you are aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it.
If we make material changes to our e-mail practices, we will notify you here, by e-mail, and by means of a notice on our home page.
The advertising banners and other forms of advertising appearing on this Web site are sometimes delivered to you, on our behalf, by a third party. In the course of serving advertisements to this site, the third party may place or recognize a unique cookie on your browser. For more information on cookies, you can visit www.cookiecentral.com.
As we continue to develop our business, we might sell certain aspects of our entities or assets. In such transactions, user information, including personally identifiable information, generally is one of the transferred business assets, and by submitting your personal information on Wn.com you agree that your data may be transferred to such parties in these circumstances.