The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Reiko Fujita - One of the best experts on this subject based on the ideXlab platform.
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development of Transuranium Element recovery from high level radioactive liquid waste
Journal of Nuclear Science and Technology, 1996Co-Authors: Yoshie Akai, Reiko FujitaAbstract:The separation methods of Transuranium Elements (TRUs) from high-level radioactive liquid waste (HLW) are classified into two categories, such as the wet processes and dry processes. A new partitioning process which combines the wet process and dry process has been developed by Toshiba Corporation. Figure 1 shows this process which combines oxalate precipitation and electrorefining. The oxalate precipitation yields good TRU recovery and electrorefining gives good TRU separation from HLW. There are three steps in the process. First, TRUs, lanthanides and alkaline earth Elements whose oxalates are lower in solubility are recovered from HLW by the addition of oxalic acid. The previous paper(1) shows the experimental study which satisfies the requirement of 99.9% recovery of simulated TRUs from simulated HLW by the oxalate precipitation. In the second step, theseoxalates are converted to chlorides. In the final step, the TRUs are recovered on a cathode by electrorefining after dissolving the chlorides in eutectic KC1-LiC1 salt.The TRU oxalates were converted to chlorides by inducing reactions with CoCl2, HCl or CCl4 at 500 °C(2)-(4). The materials of apparatus must be using corrosion resistance at high temperature. Further, it is necessary for tetravalent TRU chlorides such as NpCl4, whose vapor pressures are high(5), to be recovered. Therefore, the conversion from oxalates to chlorides satisfies the requirements of no use of corrosive gas and lower reaction temperature.This note describes an experimental study to confirm the new partitioning process, which is found to satisfy the requirement for conversion of simulated TRU oxalates to chlorides without corrosive gas and at lower temperature.
B F Myasoedov - One of the best experts on this subject based on the ideXlab platform.
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interaction of Transuranium Elements with biologically important ligands structural and spectroscopic evidence for nucleotide coordination to plutonium
Inorganic Chemistry, 2009Co-Authors: G B Andreev, N A Budantseva, M N Sokolova, I G Tananaev, B F MyasoedovAbstract:The first complex of a Transuranium Element (tetravalent plutonium) with nucleotide (deoxycytidinemonophosphate, dCMP) was synthesized and structurally characterized. The crystal structure of [Pu4(...
Yoshie Akai - One of the best experts on this subject based on the ideXlab platform.
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development of Transuranium Element recovery from high level radioactive liquid waste
Journal of Nuclear Science and Technology, 1996Co-Authors: Yoshie Akai, Reiko FujitaAbstract:The separation methods of Transuranium Elements (TRUs) from high-level radioactive liquid waste (HLW) are classified into two categories, such as the wet processes and dry processes. A new partitioning process which combines the wet process and dry process has been developed by Toshiba Corporation. Figure 1 shows this process which combines oxalate precipitation and electrorefining. The oxalate precipitation yields good TRU recovery and electrorefining gives good TRU separation from HLW. There are three steps in the process. First, TRUs, lanthanides and alkaline earth Elements whose oxalates are lower in solubility are recovered from HLW by the addition of oxalic acid. The previous paper(1) shows the experimental study which satisfies the requirement of 99.9% recovery of simulated TRUs from simulated HLW by the oxalate precipitation. In the second step, theseoxalates are converted to chlorides. In the final step, the TRUs are recovered on a cathode by electrorefining after dissolving the chlorides in eutectic KC1-LiC1 salt.The TRU oxalates were converted to chlorides by inducing reactions with CoCl2, HCl or CCl4 at 500 °C(2)-(4). The materials of apparatus must be using corrosion resistance at high temperature. Further, it is necessary for tetravalent TRU chlorides such as NpCl4, whose vapor pressures are high(5), to be recovered. Therefore, the conversion from oxalates to chlorides satisfies the requirements of no use of corrosive gas and lower reaction temperature.This note describes an experimental study to confirm the new partitioning process, which is found to satisfy the requirement for conversion of simulated TRU oxalates to chlorides without corrosive gas and at lower temperature.
Uchida Shigeo - One of the best experts on this subject based on the ideXlab platform.
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The influence of ashing temperature on the determination of Pu in soil and biological samples
2016Co-Authors: Wang Zhongtang, Zheng Jian, Tagami Keiko, Uchida ShigeoAbstract:Plutonium is the second Element in the Transuranium Element series. The current existence of Pu in natural environment originated from human nuclear activities, such as the nuclear explosion, nuclear industry and accidental release from nuclear accidents. The global fallout, as a result of the extensive atmospheric nuclear weapon tests in the last century, is the dominant Pu source in the environment. In recent years, there has been considerable concern regarding the behavior of the global fallout Pu in the environment because of the radiotoxicity associated with its alpha-emitting radioisotopes (239Pu, 240Pu) and the need of using Pu as a tracer to study geochemical processes, for example, soil erosion, sediment dating and desertification studies. In all these applications, an inevitable operation is to transfer Pu from environmental samples (e.g. soil, sediment and biological samples) to a liquid form which is compatible with the subsequent chemical treatment. In literature, many methods were presented to achieve this, such as, nitric acid leaching, total digestion method and alkali fusion method. Among these methods, nitric acid leaching is most popular because it is simple, fast and effective. Normally, the nitric acid leaching method consists of four steps: ashing, acid leaching, Pu separation and Pu measurement. The ashing step is intended to destroy the organic matter in the samples, which would have a negative impact on the Pu separation step. However, different ashing temperatures were used by researchers, from 400 to 900℃. Various ashing temperatures may cause additional uncertainty in Pu analysis. For example, low temperatures may not decompose the organic matter thoroughly; while high temperature may produce some refractory particles. Therefore, an appropriate ashing temperature should be identified and accepted by researchers to improve the reliability and accuracy of the nitric acid leaching method.Thus, in this study, efforts were made to investigate the effect of ashing temperature on accurate determination of Pu using nitric acid leaching method, for soil and biological samples. Furthermore, an optimum temperature was recommended for sample ashing
G B Andreev - One of the best experts on this subject based on the ideXlab platform.
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interaction of Transuranium Elements with biologically important ligands structural and spectroscopic evidence for nucleotide coordination to plutonium
Inorganic Chemistry, 2009Co-Authors: G B Andreev, N A Budantseva, M N Sokolova, I G Tananaev, B F MyasoedovAbstract:The first complex of a Transuranium Element (tetravalent plutonium) with nucleotide (deoxycytidinemonophosphate, dCMP) was synthesized and structurally characterized. The crystal structure of [Pu4(...
