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Goto, Minoru; Okumura, Keisuke; Nakagawa, Shigeaki; Inaba, Yoshitomo; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Katayama, Kazunari*
Fusion Engineering and Design, 136(Part A), p.357 - 361, 2018/11
Times Cited Count：6 Percentile：51.86(Nuclear Science & Technology)A High Temperature Gas-cooled Reactor (HTGR) is proposed as a tritium production device, which has the potential to produce a large amount of tritium using 
Li(n,
)T reaction. In the HTGR design, generally, boron is loaded into the core as a burnable poison to suppress excess reactivity. In this study, lithium is loaded into the HTGR core instead of boron and is used as a burnable poison aiming to produce thermal energy and tritium simultaneously. The nuclear characteristics and the fuel temperature were calculated to confirm the feasibility of the lithium-loaded HTGR. It was shown that the calculation results satisfied the design requirements and hence the feasibility was confirmed for the lithium-loaded HTGR, which produce thermal energy and tritium.
Tada, Hiroyuki*; Kumasaka, Hiroo*; Saito, Akira*; Nakaya, Atsushi*; Ishii, Takashi*; Fujita, Tomoo; Sugita, Yutaka; Nakama, Shigeo; Sanada, Masanori*
Doboku Gakkai Rombunshu, F2 (Chika Kukan Kenkyu) (Internet), 73(1), p.11 - 28, 2017/03
This study examined the mechanical characteristics of rock segments and backfill materials and analyzed the stability of the drift that is supported by the rock segments and gravel backfill. The results confirmed the technical aspects of the formation of the rock segments and the effectiveness of the planned efforts to further reduce the amount of cement used.
Kora, Kazuki*; Nakaya, Hiroyuki*; Matsuura, Hideaki*; Goto, Minoru; Nakagawa, Shigeaki; Shimakawa, Satoshi*
Nuclear Engineering and Design, 300, p.330 - 338, 2016/04
Times Cited Count：6 Percentile：48.81(Nuclear Science & Technology)In order to investigate the potential of high temperature gas-cooled reactors (HTGRs) for transmutation of long-lived fission products (LLFPs), numerical simulation of four types of HTGRs were carried out. In addition to the gas-turbine high temperature reactor system "GTHTR300", a small modular HTGR plant "HTR50S" and two types of plutonium burner HTGRs "Clean Burn with MA" and "Clean Burn without MA" were considered. The simulation results show that an early realization of LLFP transmutation using a compact HTGR may be possible since the HTR50S can transmute fair amount of LLFPs for its thermal output. The Clean Burn with MA can transmute a limited amount of LLFPs. However, an efficient LLFP transmutation using the Clean Burn without MA seems to be convincing as it is able to achieve very high burn-ups and produce LLFP transmutation more than GTHTR300. Based on these results, we propose utilization of variety of HTGRs for LLFP transmutation and storage.
Kawamoto, Yasuko*; Nakaya, Hiroyuki*; Matsuura, Hideaki*; Katayama, Kazunari*; Goto, Minoru; Nakagawa, Shigeaki
Fusion Science and Technology, 68(2), p.397 - 401, 2015/09
Times Cited Count：1 Percentile：9.61(Nuclear Science & Technology)To start up a fusion reactor, it is necessary to provide a sufficient amount of tritium from an external device. Herein, methods for supplying a fusion reactor with tritium are discussed. Use of a high temperature gas cooled reactor (HTGR) as a tritium production device has been proposed. So far, the analyses have been focused only on the operation in which fuel is periodically exchanged (batch) using the block type HTGR. In the pebble bed type HTGR, it is possible to design an operation that has no time loss for refueling. The pebble bed type HTGR (PBMR) and the block type HTGR (GTHTR300) are assumed as the calculation and comparison targets. Simulation is made using the continuous-energy Monte Carlo transport code MVPBURN. It is shown that the continuous operation using the pebble bed type HTGR has almost the same tritium productivity compared with the batch operation using the block type HGTR. The issues for pebble bed type HTGR as a tritium production device are discussed.
Nakaya, Hiroyuki*; Matsuura, Hideaki*; Katayama, Kazunari*; Goto, Minoru; Nakagawa, Shigeaki
Proceedings of 2015 International Congress on Advances in Nuclear Power Plants (ICAPP 2015) (CD-ROM), p.398 - 402, 2015/05
The performance of tritium production for fusion reactor using High-Temperature Gas-cooled Reactor (HTGR) is studied. An influence of Li concentration on tritium production performance using HTGR is estimated. Li compound is loaded in the reactor core using Li rod consisting cylindrical Li compound in cladding tube. A Gas Turbine High-Temperature Reactor of 300 MWe nominal capacity (GTHTR300) with 600 MW thermal output power is assumed as HTGR. An amount of tritium production is estimated by burn-up calculations using the continuous-energy Monte Carlo transport code MVP-BURN. The amount of tritium outflow is estimated from equilibrium solution for the tritium diffusion equation in the cladding tube. Even if 6Li is enriched, the GTHTR300 can produce 500 g of tritium over 180-day operation without increasing the amount of required Li. The amount of tritium outflow is decreased by 20-50%.
Kora, Kazuki*; Nakaya, Hiroyuki*; Kubo, Kotaro*; Matsuura, Hideaki*; Shimakawa, Satoshi; Goto, Minoru; Nakagawa, Shigeaki
Proceedings of International Conference on the Physics of Reactors; The Role of Reactor Physics toward a Sustainable Future (PHYSOR 2014) (CD-ROM), 12 Pages, 2014/09
In this study, the capability of HTGR as LLFP transmuter was evaluated in terms of neutron economy. Considering gas turbine high-temperature reactor with 300 MWe nominal capacity (GTHTR300) as HTGR, transmutations of four types of LLFP nuclide were estimated using Monte Carlo transport code MVP and ORIGEN. In addition, burn-up simulations for whole-core region were carried out using MVP-BURN. It was numerically shown that the neutron fluxes change significantly depending on the arrangement of LLFP in the core. When 15 t of LLFP is placed in an ideal manner, the GTHTR300 can sustain sufficient reactivity for one year while transmuting up to 30 kg per year. Additionally, there are more space available for storing larger amount of LLFP without affecting the reactivity. These results suggest that there is a possibility of using GTHTR300 as both LLFP storage and transmuter.
Tada, Hiroyuki*; Kumasaka, Hiroo*; Saito, Akira*; Nakaya, Atsushi*; Ishii, Takashi*; Sanada, Masanori; Noguchi, Akira*; Kishi, Hirokazu*; Nakama, Shigeo; Fujita, Tomoo
Dai-13-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (CD-ROM), p.133 - 138, 2013/01
The authors have been developing methods for constructing tunnels using the minimum quantities of cement-type support materials in high-level radioactive waste disposal facilities and advancing research and development about the technical formation of rock segment using low alkaline mortar. In this study, the mechanical characteristic values concerning the rock segment and backfill materials were examined. The stability analysis of tunnel supported by the rock segment and backfilling with gravel were performed. Technical formation and effectiveness of the alternative supports planned for further reduction in cement influence was confirmed from a study result above-mentioned.
Hayashi, Katsuhiko; Noguchi, Akira; Kishi, Hirokazu; Kabayashi, Yasushi*; Nakama, Shigeo; Fujita, Tomoo; Naito, Morimasa; Tada, Hiroyuki*; Kumasaka, Hiroo*; Goke, Mitsuo*; et al.
JAEA-Research 2010-057, 101 Pages, 2011/03
JAEA-Research-2010-057.pdf:7.47MB
Cement-type materials that are used for supports or grouting at high-level radioactive waste disposal facilities leach into the groundwater and create a highly alkaline environment. Of concern in highly alkaline environments are the alteration of bentonite used as buffers or backfill materials, and of surrounding rock mass, and the increased uncertainty regarding the provision of performance of the disposal system over a long period of time. In this study, to reduce the quantity of cement-type materials that cause highly alkaline environments, technical feasibility of the support structure including the materials which considered the long-term performance of the HLW disposal system are discussed by using knowledge and technology accumulated in JAEA and Shimizu Construction. Moreover, based on the results, the problems remained in the application to the future HLW disposal institution are summarized.
Yasumoto, Takashi*; Matsuura, Hideaki*; Shimakawa, Satoshi; Nakao, Yasuyuki*; Kochi, Shohei*; Nakaya, Hiroyuki*; Goto, Minoru; Nakagawa, Shigeaki; Nishikawa, Masabumi*
no journal, ,
no abstracts in English
Kochi, Shohei*; Nakaya, Hiroyuki*; Shimakawa, Satoshi; Matsuura, Hideaki*; Yasumoto, Takashi*; Nakao, Yasuyuki*; Goto, Minoru; Nakagawa, Shigeaki
no journal, ,
no abstracts in English
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
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.
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.
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.
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.
Yasumoto, Takashi*; Matsuura, Hideaki*; Shimakawa, Satoshi; Nakao, Yasuyuki*; Kochi, Shohei*; Nakaya, Hiroyuki*; Goto, Minoru; Nakagawa, Shigeaki
no journal, ,
no abstracts in English
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.
Goto, Minoru; Nakagawa, Shigeaki; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Katayama, Kazunari*
no journal, ,
A high temperature gas-cooled reactor (HTGR) is proposed as a tritium production device, which can produce a large amount of tritium by loading coated Li pebbles into the core without a major change of the original reactor core design. The engineering study was performed to clarify the problem of the tritium production system and assess the possibility of the resolution. As a result, it was assessed that all of the problems could be resolved from an engineering view point by using the HTTR (High Temperature engineering Test Reactor) experiences on the production of the coated fuel particles and deal of the fuels.
Goto, Minoru; Nakagawa, Shigeaki; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Katayama, Kazunari*
no journal, ,
The tritium fuel production system using a high-temperature gas-cooled reactor is proposed for initial fusion reactors. In this study, the feasibility assessment of the system was performed from the view point of engineering and safety.
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.
Goto, Minoru; Okumura, Keisuke; Nakagawa, Shigeaki; Matsuura, Hideaki*; Nakaya, Hiroyuki*; Katayama, Kazunari*
no journal, ,
A feasibility study of a High Temperature Gas-cooled Reactor (HTGR) for tritium production using Li(n,)T reaction for fusion reactors has been conducted. In this study, the burn-up chain was modified to treat Li(n,a)T reaction directory in neutronics calculations, and then the feasibility study was performed from the view point of nuclear characteristics using SRAC code system, which has experience in neutronics analysis of HTGRs.
