Evaluation of soluble organic compounds generated by radiological degradation of asphalt

Fukumoto, Masahiro; Nishikawa, Yoshiaki*; Kagawa, Akio; Kawamura, Kazuhiro

JNC TN8400 2001-002, 23 Pages, 2000/12

JNC-TN8400-2001-002.pdf:0.55MB

The soluble organic compounds generated by radiological degradation of asphalt ( ray) were confirmed as a part of influence of the bituminized waste degradation in the TRU waste repository. Especially, the influence of the nitrate was focused on. As a result, the concentration of the soluble organic compounds generated by radiological degradation of asphalt (10MGy, ray which is correspond to absorbed dose of asphalt for 1,000,000 years) were lower (each formic acid : about 50mg/dm, acetic acid : about 30mg/dm and oxalic acid : about 2mg/dm) than that of the formic acid, the acetic acid and the oxalic acid which Valcke et al. had shown (the influence of the organic at the solubility examination which uses Pu and Am). Moreover, the change in the concentration of TOC and the soluble organic compounds (formic acid, acetic acid and oxalic acid) is little under the existence of nitrate ion. That is, the formic acid and acetic acid which can be organic ligands were generated little by oxidative decomposition of asphalt in the process that nitrate ion becomes nitrite ion by radiation. The influence of the soluble organic compounds by the radiological degradation of the asphalt ( ray) on adsorption and solubility by the complexation of radionuclides in the performance assessment can be limited.

Pu(IV) Nitrate crystallization behavior confirmation experiment

*; *; *; *

JNC TJ8400 2000-061, 92 Pages, 2000/03

JNC-TJ8400-2000-061.pdf:8.79MB

Crystallization procedure is considered to have an advantage in recovering rather pure uranium from contaminated uranium solution and to be applicable for a new reprocessing process. It was confirmed until last year that the reprocessing process with crystallization procedure has a sufficient advantage. But the data for Pu crystallization is very rare. although it is necessary for design of the process with crystallization procedure. In this study, a beaker scale plutonium test was performed in AEA Technology Harwell Laboratory to confirm a behavior of Pu (IV) nitrate under crystallization condition. The results were examined by Mitsubishi Materials Corporation. Test item was a measurement of temperature in case of Pu (IV) nitrate crystallization or freezing of the solution in the following six parameters. (Pu(g/L):200, 100, 50, HNO(m):6, Pu valence:4). (Pu(g/L):200, 100, 50, HNO(m):4, Pu valence:4). Test results were as follows. (1)Pu(IV) nitrate crystallization was not observed even in the case 200g Pu/L and HNO 6M and 4M which were considered to the best condition but crystal of HO and HNO 3HO were observed. (2)Similar results were obtained for the other parameter with lower Pu concentration. (3)We can estimate that Pu(IV) nitrate crystallization will not occurred in the reprocessing process with crystallization procedure. (4)The solubility data of Pu(NO) - HNO-HO system was obtained.

Changes in the fulexural strength of engineering ceramics after high temperature sodium corrosion test; Influence after sodium exposure for 1000 hours

; Kano, Shigeki; ; Tachi, Yoshiaki; Hirakawa, Yasushi; Yoshida, Eiichi

PNC TN9410 98-021, 68 Pages, 1998/02

PNC-TN9410-98-021.pdf:6.01MB

Engineering ceramics have excellent properties such as high strength, high hardness and high heat resistance compared with metallic matelials. To apply the ceramic in fast reactor environment, it is necessary to evaluate the sodium compatibility and the influence of sodium on the mechanical properties of ceramics. In this study, the influence of high temperature sodium on the mechanical properties of sintered ceramics of conventional and high purity AlO, SiC, SiAlON, AlN and unidirectional solidified ceramics of AlO/YAG eutectic composite were investigated by means of flexure tests. Test specimens were exposed in liquid sodium at 823K and 923K for 3.6Ms. There were no changes in the flexural strength of the conventional and high purity AlO, AlN and AlO/YAG eutectic composite after the sodium exposure at 823K. On the contrary, the decrease in the flexural strength was observed in SiC and SiAlON. After the sodium exposure at 923K, there were also no changes in the flexural strength of AlN and AlO/YAG eutectic composite. In the conventional and high purity AlO and SiC, the flexural strength decreased and signs of grain boundary corrosion were detected by surface observation. The flexural strength of SiAlON after the sodium exposure at 923K increased instead of severe corrosion. In the specimens those showed no changes in the flexural strength, further exposure in sodium is needed to verify whether the mechanical properties degrade or not. For SiAlON, it is necessary to clarify the reason for the increased strength after the sodium exposure at 923K.

Effect of emzymes on the necroses of rat kidney tissues caused by needle-typed polymer formulations with controlled release of cisplatin

Yoshida, Masaru; Asano, Masaharu; Kaetsu, Isao; Imai, K.*; Mashimo, Toru*; Yuasa, Hisako*; Yamanaka, Hidetoshi*; Suzuki, K.*; Morita, Y.*

Jinko Zoki, 16(3), p.1333 - 1336, 1987/03

no abstracts in English

Thermodynamic evaluation of molten-core concrete interaction

Kitagaki, Toru; Ikeuchi, Hirotomo; Yano, Kimihiko; Ogino, Hideki; Washiya, Tadahiro

no journal, , 

Numerical simulation of distribution of melt component in reactor

Sato, Takumi; Hirata, Naoya*; Oikawa, Katsunari*; Nagae, Yuji; Kurata, Masaki

no journal, , 

Macroscopic segregation of molten core and melt components occurs with slow cooling rate in the accident of Fukushima Daiichi Nuclear Power Plants. In this study, solidification and microscopic segregation are simulated with the Scheil model and thermal properties calculated by Thermo-calc in order to investigate an influence of cooling conditions on macroscopic segregation. A macroscopic segregation behaviour has been calculated for UO-ZrO-FeO system, which are major oxides of molten core materials in various conditions. According to calculated results, UO and ZrO were concentrated in initial solidification area. On the other hand, FeO was strongly concentrated in later solidification area. FeO was significantly segregated because FeO does not be dissolved in UO and ZrO. In addition, macroscopic segregation tends to become stronger in the conditions of slow solidification rate and fast velocity of solidification interface.

Numerical simulation of distribution of melt component in reactor

Sato, Takumi; Hirata, Naoya*; Oikawa, Katsunari*; Nagae, Yuji; Kurata, Masaki

no journal, , 

Macroscopic segregation of molten core and melt components occurs with slow cooling rate in the accident of Fukushima Daiichi Nuclear Power Plants. In this study, solidification and microscopic segregation are simulated with the Scheil model and thermal properties calculated by Thermo-calc in order to investigate an influence of cooling conditions on macroscopic segregation. A macroscopic segregation behaviour has been calculated for UO-ZrO-FeO system, which are major oxides of molten core materials. According to calculated results, UO and ZrO was concentrated in initial solidification area. On the other hand, FeO were strongly concentrated in later solidification area. In addition, macroscopic segregation tends to be suppressed in the conditions of fast solidification rate and slow velocity of solidification interface.

Development of solidification and segregation model for molten corium

Sato, Takumi; Oikawa, Katsunari*; Ueshima, Nobufumi*; Nagae, Yuji; Kurata, Masaki

no journal, , 

Macroscopic segregation of molten core components occurs with slow cooling rate in the accident of Fukushima Daiichi Nuclear Power Plants. In order to investigate these segregation behavior, the solidification model for numerical simulation has been developed. In this model, solidification and microscopic segregation of molten corium are simulated with the Scheil model and thermal properties calculated by Thermo-calc. In this study, the validation of macrosegregation analysis of this model were performed. As the preliminary analysis, the calculation results were compared with corium solidification experiments. It was proved that this model can estimate the tendencies of macrosegregation.