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Journal Articles

Impact of revised thermal neutron capture cross section of carbon stored in JENDL-4.0 on HTTR criticality calculation

Goto, Minoru; Shimakawa, Satoshi; Nakao, Yasuyuki*

Journal of Nuclear Science and Technology, 48(7), p.965 - 969, 2011/07

 Times Cited Count:14 Percentile:74.79(Nuclear Science & Technology)

In the past, benchmark calculations of criticality approach for the HTTR, which is a Japanese HTGR, were performed by research institutes in several countries, and almost all of the calculations overestimated the excess reactivity. In Japan, the benchmark calculations performed by JAEA also resulted in overestimation. JAEA improved the calculations by revising the geometric model and replacing the nuclear data library with JENDL-3.3, which was the latest JENDL at that time. However, the overestimation remained and this problem has not been resolved until today. We performed calculations of the HTTR criticality approach with several nuclear data libraries, and found that slight difference in the capture cross section of carbon at thermal energy among the libraries causes significant difference in the $$k$$$$_{eff}$$ values. The cross section value of carbon was not concerned in reactor neutronics calculation because of its small value of the order of 10$$^{-3}$$ burn, and consequently the cross section value was not revised for a long time even in the major nuclear data libraries: JENDL, ENDF/B and JEFF. We thought that the cross section value should be revised based on the latest measurement data in order to improve the accuracy of the neutronics calculations of the HTTR. In April 2010, the latest JENDL;JENDL-4, was released by JAEA, and the capture cross section of carbon was revised. JENDL-4 yielded 0.4%$$Delta$$$$k$$-0.9%$$Delta$$$$k$$ smaller $$k$$$$_{eff}$$ values than JENDL-3.3 in the calculation of the HTTR critical approach, and consequently the problem of the overestimation of the excess reactivity in the HTTR benchmark calculation was resolved.

Journal Articles

Experimental validation of effectiveness of rod-type burnable poisons on reactivity control in HTTR

Goto, Minoru; Shiozawa, Shusaku; Fujimoto, Nozomu; Nakagawa, Shigeaki; Nakao, Yasuyuki*

Nuclear Engineering and Design, 240(10), p.2994 - 2998, 2010/10

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

In block type high temperature gas-cooled reactors (HTGRs), insertion depth of control rods (CRs) into a core should be retained as shallow as possible to keep fuel temperature below limit through a burnup period. Using burnable poisons (BPs) to control reactivity is considered as a method to resolve this problem as in case of light water reactors (LWRs). BPs design method for LWRs has been validated by experimental data, however, that for HTGRs have not been yet, because there was not burnup characteristics data of HTGRs required for the validation. The High Temperature engineering Test Reactor (HTTR) is a block type HTGRs and it uses BPs to control reactivity. The HTTR has been operated up to middle burnup, and thereby the experimental data was expected to show effect of the BPs on the reactivity control. Hence, in order to validate the BPs design method, we investigated whether the BPs have functioned as designed. As a result, the CRs insertion depth has been retained shallow within allowable range, and then the BPs design method was validated.

Journal Articles

Soft-lithographic methods for the fabrication of dielectrophoretic devices using molds by proton beam writing

Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Furuta, Yusuke*; kanamitsu, Kaoru*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*

Microelectronic Engineering, 87(5-8), p.835 - 838, 2010/05

 Times Cited Count:6 Percentile:40.19(Engineering, Electrical & Electronic)

Journal Articles

The Preliminary analysis of the loss of primary coolant flow test in the HTTR

Nakagawa, Shigeaki; Takamatsu, Kuniyoshi; Goto, Minoru; Takeda, Tetsuaki*; Nakao, Yasuyuki*

Proceedings of 4th International Topical Meeting on High Temperature Reactor Technology (HTR 2008) (CD-ROM), 8 Pages, 2008/09

Loss of primary coolant flow test is under planning by using the HTTR to demonstrate the inherent safety features during the accident condition such as the depressurization accident which is selected as the severest accident in the HTGR. All the gas circulators are tripped in the test and the position of all control rods keeps its initial one. Because the core temperature increases just after the loss of coolant flow, the reactor power decreases according to coolant flow decrease due to negative reactivity feedback effect and the reactor becomes subcritical. The reactor performance after becoming subcritical during the loss of coolant flow is subject to a reactivity balance of core temperature and xenon concentration changes. The loss of primary coolant flow test in the HTTR simulates the depressurization accident and the data obtained from the test is useful for the validation and improvement of the calculation code applied to the safety analysis in the future HTGR.

Journal Articles

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

 Times Cited Count:51 Percentile:73.43(Biochemistry & Molecular Biology)

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.

Oral presentation

Safety demonstration test for high temperature gas-cooled reactor by using the high temperature engineering test reactor

Nakagawa, Shigeaki; Takamatsu, Kuniyoshi; Takeda, Tetsuaki; Iyoku, Tatsuo; Nakao, Yasuyuki*

no journal, , 

no abstracts in English

Oral presentation

Analysis on reactor performance during the loss of flow test in HTTR

Nakagawa, Shigeaki; Takamatsu, Kuniyoshi; Goto, Minoru; Takeda, Tetsuaki; Nakao, Yasuyuki*

no journal, , 

no abstracts in English

Oral presentation

Development of dielectrophoretic devices with high-aspect ratio microstructures using proton beam writing

Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Furuta, Yusuke*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*

no journal, , 

Oral presentation

Replication of micro-channels on PDMS using SU-8 mold fabricated by proton beam writing

Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Mori, Toshiki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*

no journal, , 

no abstracts in English

Oral presentation

Influence of the nuclear data library in the core calculation of a high temperature gas-cooled reactor

Yasumoto, Takashi*; Goto, Minoru; Shimakawa, Satoshi; Nakagawa, Shigeaki; Seki, Yasuyoshi; Matsuura, Hideaki*; Nakao, Yasuyuki*

no journal, , 

Core calculation of the HTTR yielded overestimation of the excess reactivities to the experimental data, and this problem has not been resolved yet. It is one of the important issue to select nuclear data library, which was used for the core calculations, to obtain the calculation results with high accuracy. In the past, the effect of difference of nuclear data libraries on the HTTR core calculation results was evaluated using JENDL-3.3, ENDF/B-6.8 and JEFF-3.1. As a result, JENDL-3.3 yielded better excess reactivities than ENDF/B-6.8 and JEFF-3.1. In this study, the effect was reevaluated using the latest version of ENDF/B: ENDF/B-7.0 and the preliminary version of JENDL-4.

Oral presentation

Fabrication of three-dimensional pillar arrays by PBW for improved trapping performance of dielectrophoretic devices

Shiine, Yasuharu*; Sakashita, Yusuke*; Nishikawa, Hiroyuki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*

no journal, , 

Oral presentation

Study for tritium production for fusion reactors by high temperature gas-cooled reactors

Yasumoto, Takashi*; Matsuura, Hideaki*; Shimakawa, Satoshi; Nakao, Yasuyuki*; Kochi, Shohei*; Nakaya, Hiroyuki*; Goto, Minoru; Nakagawa, Shigeaki

no journal, , 

no abstracts in English

Oral presentation

Study for tritium production for fusion reactors by high temperature gas-cooled reactors

Yasumoto, Takashi*; Matsuura, Hideaki*; Shimakawa, Satoshi; Nakao, Yasuyuki*; Kochi, Shohei*; Nakaya, Hiroyuki*; Goto, Minoru; Nakagawa, Shigeaki; Nishikawa, Masabumi*

no journal, , 

no abstracts in English

Oral presentation

Study to transmute long life fission products into short-lived nuclides

Kochi, Shohei*; Nakaya, Hiroyuki*; Shimakawa, Satoshi; Matsuura, Hideaki*; Yasumoto, Takashi*; Nakao, Yasuyuki*; Goto, Minoru; Nakagawa, Shigeaki

no journal, , 

no abstracts in English

Oral presentation

Study for tritium production for fusion reactor by high-temperature gas-cooled reactor

Matsuura, Hideaki*; Yasumoto, Takashi*; Shimakawa, Satoshi; Kochi, Shohei*; Nakaya, Hiroyuki*; Nakao, Yasuyuki*; Goto, Minoru; Nakagawa, Shigeaki; Nishikawa, Masabumi*

no journal, , 

no abstracts in English

Oral presentation

Performance of high-temperature gas-cooled reactor as a tritium production device for fusion reactors

Matsuura, Hideaki*; Kochi, Shohei*; Nakaya, Hiroyuki*; Yasumoto, Takashi*; Nakao, Yasuyuki*; Shimakawa, Satoshi; Goto, Minoru; Nakagawa, Shigeaki; Nishikawa, Masabumi*

no journal, , 

The performance of a high-temperature gas-cooled reactor as a tritium production device for fusion reactors was examined by performing a core burn-up calculation with the continuous-energy Monte Carlo code MVP-BURN. It was shown that the high-temperature gas cooled reactor can contribute to the tritium production for fusion reactors.

Oral presentation

Use of Li control rod and performance of tritium production in high-temperature gas-cooled reactors

Kochi, Shohei*; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Nakao, Yasuyuki*; Shimakawa, Satoshi; Goto, Minoru; Nakagawa, Shigeaki; Nishikawa, Masabumi*

no journal, , 

Changes in a control rod value and a production amount of tritium with burnup were examined with a continuous energy Monte Carlo code MVP-BURN for a high temperature gas cooled reactor in which B$$_{4}$$C control rods were replaced with Li control rods. It was shown that the amount of tritium production was increased about 20% from the previous study and the excess reactivity was properly controlled by installing the Li control rods into the outer region of the core.

Oral presentation

Study of transmutation treatment of long-lived fission products with high temperature gas cooled reactor; Characteristics

Shimakawa, Satoshi; Goto, Minoru; Nakagawa, Shigeaki; Nakaya, Hiroyuki*; Matsuura, Hideaki*; Nakao, Yasuyuki*

no journal, , 

In order to decrease of nuclear waste, the nuclear transmutation method with HTGRs (High Temperature Gas-cooled Reactor) by which a large amount of LLFP (Long Lived Fission Product) can be transmuted is proposed. This paper describes the characteristics of the nuclear transmutation, which are the relations between transmutation efficiency and the amount of loaded LLFP into the core or the characteristics of the irradiation target, are reported.

Oral presentation

Study of tritium production with high temperature gas cooled reactor, 2; Engineering investigation

Goto, Minoru; Nakagawa, Shigeaki; Shimakawa, Satoshi; Matsuura, Hideaki*; Nakao, Yasuyuki*; Nishikawa, Masabumi*; Nakaya, Hiroyuki*

no journal, , 

A High Temperature Gas-cooled Reactor (HTGR) with lithium particle, which can produce a large amount of tritium without the change of the original reactor design, is proposed as a tritium production device for an initial fusion reactor. However, the tritium production using High Temperature Engineering Test Reactor (HTGR) is not carried out so far and the investigation of the problem about its system is not carried out so far, too. Therefore we extracted a problem from an engineering viewpoint and investigated the feasibility. The problems are expected to be solved by using the HTTR technologies, which are manufacturing the coated fuel particle and handling of the fuel, and the system is feasible from an engineering viewpoint.

Oral presentation

Study of tritium production with high temperature gas cooled reactor, 1; Study of operation scenario

Nakaya, Hiroyuki*; Matsuura, Hideaki*; Nakao, Yasuyuki*; Nishikawa, Masabumi*; Goto, Minoru; Shimakawa, Satoshi; Nakagawa, Shigeaki

no journal, , 

111The performance of the tritium production by High Temperature Gas-cooled Reactor (HTGR) was evaluated in case of using GTHTR300 as a HTGR. In the evaluation, parametric study was performed for the fuel exchange period and the operation period for one batch. The amount of tritium production was calculated by whole core burnup calculation using the continuous-energy Monte Carlo transport code MVP-BURN. As a result, 23 kg of tritium, which is required for a fusion reactor as fuel, is produced for 1.7 year with the condition in which the fuel exchange period and the operation period are set to 30 days and 240 days, respectively.

Oral presentation

Study on transmutation of long-lived fission products using high temperature gas cooled reactor; Effect of ma admixture on transmutation

Kubo, Kotaro*; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Kawamoto, Yasuko*; Nakao, Yasuyuki*; Shimakawa, Satoshi; Goto, Minoru; Nakagawa, Shigeaki

no journal, , 

The transmutation performance for LLFP and Mainer Actinide (MA) was evaluated when 2t of Tc-99 and 50kg of MA was loaded into GTHTR300 core. The compositions of MA was defined as the same as the spent fuel of a PWR with 12 years cooling. The amounts of transmutation were analyzed by performing the burn-up calculation with MVP-BURN for a fuel block geometry. As a result, the transmutation performance of GTHTR300 was evaluated that 18 kg of Tc-99 and 10 kg of MA were transmutated by one year operation.

21 (Records 1-20 displayed on this page)