Naoyuki Takaki
Tokyo Institute of Technology
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Naoyuki Takaki.
Journal of Nuclear Science and Technology | 2007
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto
The performances of a light water cooled thorium breeder reactor have been investigated. A feasible region of fresh fuel enrichment and moderator to fuel ratio (MFR) is found to satisfy the constrains of criticality, breeding, and negative void coefficient for several burnups of discharged fuel. The equilibrium fuel cycle burnup calculation has been performed which is coupled with the cell calculation. The MFR is changed to investigate its effect to the breeding capability and void reactivity coefficient profile for different average discharged burnups. For moderated cases, the conversion ratio (CR) decreases with increasing burnup and MFR. The ratio of fissile inventory in equilibrium core to the initial fissile loading (FIR) has the maximum value at certain burnups depending on the MFR and its value increases with the decreasing MFR. Considering to the breeding capability of the reactor, for burnups of equal to 30 GWd/t or higher, the MFR ≤ 0.3 is needed. For the larger MFR and lower burnups, the void reactivity coefficient becomes more negative with an increasing void fraction. The most negative value of the void reactivity coefficient is obtained at MFR = 0:3.
THE 3RD INTERNATIONAL CONFERENCE ON ADVANCES IN NUCLEAR SCIENCE AND ENGINEERING 2011: ICANSE 2011 | 2012
Naoyuki Takaki; Azuma Namekawa; Tomoyuki Yoda; Akihiko Mizutani; Hiroshi Sekimoto
The CANDLE burning process is characterized by the autonomous shifting of burning region with constant reactivity and constant spacial power distribution. Evaluations of such critical burning process by using widely used neutron diffusion and burning codes under some realistic engineering constraints are valuable to confirm the technical feasibility of the CANDLE concept and to put the idea into concrete core design. In the first part of this paper, it is discussed that whether the sustainable and stable CANDLE burning process can be reproduced even by using conventional core analysis tools such as SLAROM and CITATION-FBR. As a result, it is certainly possible to demonstrate it if the proper core configuration and initial fuel composition required as CANDLE core are applied to the analysis. In the latter part, an example of a concrete image of sodium cooled, metal fuel, 2000MWt rating CANDLE core has been presented by assuming an emerging inevitable technology of recladding. The core satisfies engineering...
THE 2ND INTERNATIONAL CONFERENCE ON ADVANCES IN NUCLEAR SCIENCE AND ENGINEERING 2009‐ICANSE 2009 | 2010
Deby Mardiansah; Naoyuki Takaki
Deployment scenario of heavy water cooled thorium breeder reactor has been studied. We have assumed to use plutonium and thorium oxide fuel in water cooled reactor to produce 233U which will be used in thorium breeder reactor. The objective is to analysis the potential of water cooled Th‐Pu reactor for replacing all of current LWRs especially in Japan. In this paper, the standard Pressurize Water Reactor (PWR) has been designed to produce 3423 MWt; (i) Th‐Pu PWR, (ii) Th‐Pu HWR (MFR = 1.0) and (iii) Th‐Pu HWR (MFR = 1.2). The properties and performance of the core were investigated by using cell and core calculation code. Th‐Pu PWR or HWR produces 233U to introduce thorium breeder reactor. The result showed that to replace all (60 GWe) LWR by thorium breeder reactor within a period of one century, Th‐Pu oxide fueled PWR has insufficient capability to produce necessary amount of 233U and Th‐Pu oxide fueled HWR has almost enough potential to produce 233U but shows positive void reactivity coefficient.
Volume 3: Structural Integrity; Nuclear Engineering Advances; Next Generation Systems; Near Term Deployment and Promotion of Nuclear Energy | 2006
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto
Thorium as supplied fuel has good candidate for fuel material if it is converted into fissile material {sup 233}U which shows superior characteristics in the thermal region. The Shippingport reactor used {sup 233}U-Th fuel system, and the molten salt breeder reactor (MSBR) project showed that breeding is possible in a thermal spectrum. In the present study, feasibility of water cooled thorium breeder reactor is investigated. The key properties such as flux, {eta} value, criticality and breeding performances are evaluated for different moderator to fuel ratios (MFR) and burn-ups. The results show the feasibility of breeding for different MFR and burn-ups. The required {sup 233}U enrichment is about 2% - 9% as charge fuel. The lower MFR and the higher enrichment of {sup 233}U are preferable to improve the average burn-up; however the design feasible window is shrunk. This core shows the design feasible window especially in relation to MFR with negative void reactivity coefficient. (authors)
Annals of Nuclear Energy | 2009
Akito Nagata; Naoyuki Takaki; Hiroshi Sekimoto
Progress in Nuclear Energy | 2008
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto
Annals of Nuclear Energy | 2006
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto
Annals of Nuclear Energy | 2011
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto
Progress in Nuclear Energy | 2008
Permana Sidik; Naoyuki Takaki; Hiroshi Sekimoto
Journal of Nuclear Science and Technology | 2008
Sidik Permana; Naoyuki Takaki; Hiroshi Sekimoto