[en] Electrowinning is a electrochemical process to simultaneously recover transuranium as well as uranium by using a liquid cadmium cathode (LCC). U ions are known to be deposited on the LCC in the form of dendrites having large surface area. These U dendrites were difficult to settle down into the liquid Cd even if the density of U was even larger than that of Cd. The floating U dendrites on the LCC have a role of solid cathode and so co-deposition of U and TRU could be hampered. So, LCC agitators have been developed to prevent U from forming dendrites, for example, blade stirrer and pounder in Japan and United States, respectively. According to the U-Cd phase diagram, U or UCd₁₁ phases are, respectively, stable above and below 473 .deg. C when both U and Cd elements are coexisted. Up to now, electrodeposition experiments of actinides on the LCC have usually been carried out above 473 .deg. C, especially at around 500 .deg. C. If UCd₁₁ phases do not have a dendrite form in the process of a electrodeposition, these phases may sink into the liquid Cd even when no-stirring of LCC. This will be a good method to enhance the recovery rates of actinide elements. In this study, we observed if the UCd₁₁ phases could go down to Cd without a stirring of LCC

[en] The manufacture of transuranium element sources is described. The isotopes employed and the techniques used to prepare the sources are reviewed

[en] The thought that some elements beyond uranium could still occur in nature has never quite faded, since breaking off the list of known elements in the case of uranium revealed no physical or chemical justification. It is true that the conclusion was drawn that the elements beyond uranium could only have short-lived isotopes, which would have to have died out since the formation of the earth without re-production. This argument, which allowed us to recognize the limit at uranium as accidental, and which, according to our current knowledge, remains correct, always left open the possibility of looking for trace occurrences of the elements beyond uranium. (author)

[en] Plutonium 238, americium 241 and californium 252 possess very interesting nuclear characteristics and can be used for various applications. The Department of Plutonium Fuel Studies has developed a certain number of radioisotopic sources during the last few years. The most interesting are presented, with their field of application. Plutonium 238: X radiation sources for X-fluorescence analysis; prototype low-activity neutron source, of intermittent fluence; α sources for ionometric smoke detector. Americium 241: α sources for ionometric smoke detector. Californium 252: high activity neutron sources for industrial applications; low-activity neutron sources for medical use (neutrontherapy)

[en] This issue of TRAN-STAT is concerned with three related topics: results from the questionnaire included with the 3rd issue of TRAN-STAT, the role of the statistician in transuranic studies, and some effective ways for exploring data sets and communicating this information to others via effective data summaries

[en] This paper reviews some historical aspects of the knowledge and discovery of transuranium elements. This fission of plutonium is discussed also. 12 refs., 6 figs

[en] In this paper, and forming part of a more global study carried out by the Applied Nuclear Physics Research Group of the University of Seville about the radioecological impact of anthropogenic radioactive contamination in particulate form, we show the results obtained in some lixiviation experiments performed with hot particles collected in areas where several nuclear tests were done especially in the midlle of the XXth century (Semipalatinsk, Nevada). These particles were submitted to a lixiviation process with 0.16M HCl (solution that simulate the acidity and behavior of the gastric juices in the accidental ingestion of these particles), determining the percentage of 238Pu, 239+240Pu and 241Am lixiviated after their separation and isolation from the eluates using anion exchange resins and after their measurement by high-resolution alpha-particle spectrometry. The obtained results indicate that the percentage lixiviated for the radionuclides under study is very low (in all the cases lower than 1%) and clearly lower to the observed one in similar experiments with soil samples containing anthropogenic plutonium and americium in the aerosol form.

No abstract available

[en] Methods of obtaining various transuranium elements are given. Also described are methods of producing transuranium elements by reactions of heavy ions. The presence is discussed of certain transuranium elements in nature. (M.D.)

[en] A very brief account is given of the research programmes in the USSR leading to the production of plutonium and other transuranium elements. (U.K.)