Transuranic

The rapid fission of a mass of or another heavy nucleus is the principle of the atomic bomb, the energy liberated being the destructive power. For useful energy the reaction has to be moderated this is done in a reactor where moderators such as water, heavy water, graphite, beryllium, etc., reduce the number of neutrons and slow those present to the most useful energies. The heat produced in a reactor is removed by normal heat-exchange methods. The neutrons in a reactor may be used for the formation of new isotopes, e.g. the transuranic elements, further fissile materials ( °Pu from or of the... 

Albert Einstein) Einsteinium, the seventh transuranic element of the actinide series to be discovered, was identified by Ghiorso and co-workers at Berkeley in December 1952 in debris from the first large thermonuclear explosion, which took place in the Pacific in November, 1952. The 20-day 253Es isotope was produced. 

Apart from naturally occurring elements, there are now newly made elements beyond uranium. These constitute the transuranic series. All the elements in this series are radioactive. 

Transportation Index Transport phenomena Transposons Transputer chips Transuranic waste Transuranium elements... 

Transurane, Gmelins Handhuch der anorganischen Chemie, Part A, The Elements, Vedag Chemie GmbH, Weinheim/Bergstrasse, 1972—1973, A1,1,1973, A1,II, 1974. 

Spent nuclear fuel has fission products, uranium, and transuranic elements. Plans call for permanent disposal in underground repositories. Geological studies are in progress at the Yucca Mountain site in Nevada. Until a repository is completed, spent fuel must be stored in water pools or in dry storage casks at nuclear plant sites. 

Nuclear wastes are classified according to the level of radioactivity. Low level wastes (LLW) from reactors arise primarily from the cooling water, either because of leakage from fuel or activation of impurities by neutron absorption. Most LLW will be disposed of in near-surface faciHties at various locations around the United States. Mixed wastes are those having both a ha2ardous and a radioactive component. Transuranic (TRU) waste containing plutonium comes from chemical processes related to nuclear weapons production. These are to be placed in underground salt deposits in New Mexico (see... 

As the recycled fuel composition approaches steady state after approximately four cycles (1), the heat and radiation associated with and Pu require more elaborate conversion and fuel fabrication facihties than are needed for virgin fuel. The storage, solidification, packaging, shipping, and disposal considerations associated with wastes that result from this approach are primarily concerned with the relatively short-Hved fission products. The transuranic... 

Classification of wastes may be according to purpose, distinguishing between defense waste related to military appHcations, and commercial waste related to civiUan appHcations. Classification may also be by the type of waste, ie, mill tailings, high level radioactive waste (HLW), spent fuel, low level radioactive waste (LLW), or transuranic waste (TRU). Alternatively, the radionucHdes and the degree of radioactivity can define the waste. Surveys of nuclear waste management (1,2) and more technical information (3—5) are available. 

Weapons materials from production reactors were accumulated during the Cold War period as a part of the U.S. defense program. Prominent were tritium, ie, hydrogen-3, having a of 12.3 yr, and plutonium-239, 1/2 = 2.4 X lO" yr. The latter constitutes a waste both as a by-product of weapons fabrication in a waste material called transuranic waste (TRU), and as an excess fissionable material if not used for power production in a reactor. 

Transuranic Waste. Transuranic wastes (TRU) contain significant amounts (>3,700 Bq/g (100 nCi/g)) of plutonium. These wastes have accumulated from nuclear weapons production at sites such as Rocky Flats, Colorado. Experimental test of TRU disposal is planned for the Waste Isolation Pilot Plant (WIPP) site near Carlsbad, New Mexico. The geologic medium is rock salt, which has the abiUty to flow under pressure around waste containers, thus sealing them from water. Studies center on the stabiUty of stmctures and effects of small amounts of water within the repository. 

Nuclear Waste Reprocessing. Liquid waste remaining from processing of spent reactor fuel for military plutonium production is typically acidic and contains substantial transuranic residues. The cleanup of such waste in 1996 is a higher priority than military plutonium processing. Cleanup requires removal of long-Hved actinides from nitric or hydrochloric acid solutions. The transuranium extraction (Tmex) process has been developed for... 

Gmelin Handbuch derAnorganischen Chemie, Transurane, TeilB1, Metalle, Spriager-Vedag, Berlin, 1976. 

Gmelin Mandbuch derMnorganischen Chemie, Transurane, TeilD1, Chemie in Etfsung, Springer-Vedag, Berlin, 1975. 

Gmelin Handbuch derA.norganischen Chemie, Transurane, TeilJid, kment Vedag Chemie, Weinlieim, Germany, 1973. 

In 1934 Fermi decided to bombard uranium with neutrons in an attempt to produce transuranic elements, that is, elements beyond uranium, which is number 92 in the periodic table. He thought for a while that he had succeeded, since unstable atoms were produced that did not seem to correspond to any known radioactive isotope. I le was wrong in this conjecture, but the research itself would eventually turn out to be of momentous importance both for physics and for world history, and worthy of the 1938 Nobel Pri2e in Physics. 

In 1938 Niels Bohr had brought the astounding news from Europe that the radiochemists Otto Hahn and Fritz Strassmann in Berlin had conclusively demonstrated that one of the products of the bom-bardmeiit of uranium by neutrons was barium, with atomic number 56, in the middle of the periodic table of elements. He also announced that in Stockholm Lise Meitner and her nephew Otto Frisch had proposed a theory to explain what they called nuclear fission, the splitting of a uranium nucleus under neutron bombardment into two pieces, each with a mass roughly equal to half the mass of the uranium nucleus. The products of Fermi s neutron bombardment of uranium back in Rome had therefore not been transuranic elements, but radioactive isotopes of known elements from the middle of the periodic table. 

Solid transuranic interim waste storage at the U.S. Department of Energy s Idaho National Engineering Laboratory in Idaho Falls, Idaho. (U.S. Department of Energy)... 

The loose connection between electron configuration and the chemical behaviour of the heavy elements (transuranics). C. K. Jorgensen, Angew. Chem., Int. Ed. Engl., 1973,12,12-19 (73). 

Brown, D. In Gmelins Handbuch der anorganischen Chemie Band 4 -Transurane, Teil C, Verlag Chemie,Weinheim, 1972. 

Laser-induced fluorescence has proven to be the key to these pioneering studies of transuranic hexafluoride electronic state photophysics and photochemistry. This is a research area of unique opportunity in which fundamental and technical research interests strongly converge. 

Brown, D. "Gemlins Handbuch der Anorganlschen Chemle, Transurane, Tell C Die Verbindungen", G. Koch, ed. Verlag Chemie Weinhelm, 1972 pp. 100-128. 

Carnall, W. T. "Gmelin Handbook of Inorganic Chemistry", Transurane A-2 (Erg.-Werk Band 8) Verlag Chemie, Weinheim/Bergstr., 1973, 35-79. 

Techniques for Identifying Transuranic Speciation in Aqueous Environments" International Atomic Energy Agency Vienna, 1981. 

A third source of aquatic plutonium is liquid effluent discharged from laboratory operations into ponds and streams. An example of this is a former waste pond at Oak Ridge National Laboratory, Pond 3513, that received liquid wastes with low concentrations of transuranic elements before it was retired. This impoundment has water quality similar to high pH natural ponds. 

Fukai, R. Yamato, A. Thein, M. and Bilinski, H., "Techniques for Identifying Transuranic Speciation in Aquatic Environments" STI/PUB/613, International Atomic Energy Agency, Vienna, 1981, pp. 37-41. 

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