Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03

JAEA-Research-2014-030.pdf:199.23MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

Negative-U system of carbon vacancy in 4H-SiC

Son, N. T.*; Trinh, X. T.*; Lvile, L. S.*; Svensson, B. G.*; Kawahara, Kotaro*; Suda, Jun*; Kimoto, Tsunenobu*; Umeda, Takahide*; Isoya, Junichi*; Makino, Takahiro; et al.

Physical Review Letters, 109(18), p.187603_1 - 187603_5, 2012/11

https://doi.org/10.1103/PhysRevLett.109.187603

The H-Invitational Database (H-InvDB); A Comprehensive annotation resource for human genes and transcripts

Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.

Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01

https://doi.org/10.1093/nar/gkm999

Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.

Integrated on-line plant monitoring system for HTTR using neural networks

Nabeshima, Kunihiko; Matsuishi, Tomomi*; Makino, Jun*; Subekti, M.*; Ono, Tomio*; Kudo, Kazuhiko*; Nakagawa, Shigeaki

Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 6 Pages, 2007/04

The neural networks have been utilized in on-line monitoring system of High Temperature Engineering Tested Reactor (HTTR) with thermal power of 30MW. In this system, several neural networks can independently model the plant dynamics with different architecture, input and output signals and learning algorithm. One of main task is real-time plant monitoring by Multi-Layer Perceptron (MLP) in auto-associative mode, which can model and estimate the whole plant dynamics by training normal operational data only. Other tasks are on-line reactivity prediction, reactivity and helium leak monitoring, respectively. From the on-line test results, each neural network shows good prediction and reliable detection performances.

Examination of determination to Pu amount in LASW from TRP

Makino, Risa; Kabuki, Toshihide*; Tomikawa, Hirofumi; Hina, Tetsuro; Ozone, Takashi; Kurosu, Kazutoshi; Fukuhara, Junichi; Kobayashi, Kentaro

no journal, , 

Tokai Reprocessing Center has developed method of determination of Pu contained in low activity solid wastes (LASWs), to make better accountancy control. Our final goal is to estimate of Pu amounts in wastes generated in Tokai Reprocessing Plant (TRP). Some of small size wastes (carton-boxes) and drums from TRP was measured by some kind of non-destructive assay system. It was found that high dose wastes have slight amounts of Pu. However, because some of wastes from TRP have FPs, the wastes could not be measured exactly. Near future, JAEA will try upgrading or development of NDA system, and determination of Pu amount of wastes from TRP.

New small sodium leak detection system, 2; An Experiment of moving fluid ionization detector and laser leak detector in fast breeder reactor Monju

Okazaki, Koki*; Naito, Susumu*; Nakayama, Kunihiko*; Makino, Shunichiro*; Shigeyama, Musashi*; Kuwako, Akira*; Izumi, Mikio*; Ito, Jun*; Okada, Hisashi*; Muto, Keitaro

no journal, , 

In fast breeder reactor (FBR), it is important to detect a small sodium leak surely for safety. As the coolant sodium used in FBR is low pressure, a small leak occurs from a crack before a pipe breaks, therefore it is possible to detect a sodium leak so as to shutdown a reactor before a pipe completely breaks. The sodium leaking from piping of cooling system reacts with oxygen etc. including with the ambient gas to form aerosols. In the second coolant system of the prototype liquid metal FBR Monju, the ambient air around piping is drawn into radiative ionization detector (RID). When sodium aerosols are detected by RID, chemical analysis of aerosols and the viewing of the leak point are carried out, then sodium leak is confirmed. As the signal of RID depends on temperature strongly and RID detects the aerosols which do not include sodium, the improvements of RID are demanded for reliability. Moving fluid ionization detector (MID) and laser leak detector (LLD) have been developed to improve these points. MID can reduce the dependence for temperature of the signal strength, and LLD can detect sodium atoms which are included in aerosols by means of laser-induced breakdown spectroscopy. An experiment was carried out for validating sodium leak detection system with MID and LLD under real environment installed in the second coolant system of Monju. In the experiments, sodium was not leaked, and ambient air around piping of the secondary coolant system was introduced through actual sampling line and measured by MID and LLD. In addition a sodium level in the ambient air was measured by means of ion chromatography. The experiment showed that the background signals of MID and LLD were stable and low and that the sodium level due to the background of salinity (NaCl) contained in the ambient air was lower than three orders of magnitude than the sodium level for small sodium leak. The plant applicability of MID and RID was validated by this experiment.

The Carbon vacancy in SiC

Son, N. T.*; Trinh, X. T.*; Suda, Jun*; Kimoto, Tsunenobu*; Lvile, L. S.*; Svensson, B. G.*; Szasz, K.*; Hornos, T.*; Gali, A.*; Umeda, Takahide*; et al.

no journal, , 

no abstracts in English

Possibility of direct energy conversion from radiation to electricity using SiC Schottky system

Yoshii, Kenji; Fukuda, Tatsuo; Tanida, Hajime; Shiwaku, Hideaki; Kamiya, Junichiro; Makino, Takahiro*; Yamazaki, Yuichi*; Oshima, Takeshi*; Yaita, Tsuyoshi

no journal, , 

We have carried out direct energy conversion from gamma rays to electricity using SiC free of toxic elements. The experiments were done using synchrotron radiation at the BL22XU beamline. To utilize radioactive wastes as an energy source, the gamma ray energies were 30 and 60 keV, corresponding to the energies from Np and Am, respectively. Also, CuK X-rays were used to show a possibility of micro batteries using radioisotopes. The samples were Ni/SiC Schottky barrier junctions. From dark current experiments, it was found that the samples were regarded as ideal diodes on the basis of the so-called ideality factors. The electric powers under gamma rays and X-rays were found to be about 0.1W, corresponding to efficiencies less than 0.1%. We will also show the results of energy depositions on the basis of Monte Carlo methods.