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Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Goto, Ichiro*; Kibe, Satoshi*; et al.
JAEA-Review 2014-040, 115 Pages, 2015/01
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.
JAEA-Research 2010-019, 194 Pages, 2010/08
This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.
Takeda, Seiji; Yamaguchi, Tetsuji; Nagasawa, Hirokazu; Watanabe, Masatoshi; Sekioka, Yasushi; Kanzaki, Yutaka; Sasaki, Toshihisa; Ochiai, Toru; Munakata, Masahiro; Tanaka, Tadao; et al.
JAEA-Research 2009-034, 239 Pages, 2009/11
In safety assessment for geological disposal of high level radioactive waste, it is of consequence to estimate the uncertainties due to the long-term frame associated with long-lived radionuclides and the expanded geological environment. The uncertainties result from heterogeneity intrinsic to engineered and natural barrier materials, insufficient understanding of phenomena occurring in the disposal system, erroneous method of measurement, and incomplete construction. It is possible to quantify or to reduce the uncertainties according to scientific and technological progress. We applied a deterministic and a Monte Carlo-based probabilistic method simulation techniques to the uncertainty analysis for performance of hypothetical geological disposal system for high level radioactive waste. This study provides the method to evaluate the effects of the uncertainties with respect to scenarios, models and parameters in engineering barrier system on radiological consequence. The results also help us to specify prioritized models and parameters to be further studied for long-term safety assessment.
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Kawashima, Hisato; Kurita, Genichi; Tanigawa, Hiroyasu; Nakamura, Hirofumi; Honda, Mitsuru; Saito, Ai*; Sato, Satoshi; et al.
Nuclear Fusion, 49(7), p.075029_1 - 075029_10, 2009/07
Times Cited Count:135 Percentile:97.73(Physics, Fluids & Plasmas)Recent design study on SlimCS focused mainly on the torus configuration including blanket, divertor, materials and maintenance scheme. For vertical stability of elongated plasma and high beta access, a sector-wide conducting shell is arranged in between replaceable and permanent blanket. The reactor adopts pressurized-water-cooled solid breeding blanket. Compared with the previous advanced concept with supercritical water, the design options satisfying tritium self-sufficiency are relatively scarce. Considered divertor technology and materials, an allowable heat load to the divertor plate should be 8 MW/m or lower, which can be a critical constraint for determining a handling power of DEMO (a combination of alpha heating power and external input power for current drive).
Ochiai, Toru; Takeda, Seiji; Kimura, Hideo
JAEA-Data/Code 2009-003, 62 Pages, 2009/06
The objective of this study is to estimate the uncertainties on the soil-to-plant transfer factor in the safety assessment. The transfer factors for radionuclides used in the safety assessment were determined based on the results of statistical analysis for transfer factor data collected form literature survey and of comparison with the data published by IAEA. This report provides the determined values of the transfer factor, the process and grounds of determining them, and collected data of transfer factor as database.
Sawaguchi, Takuma; Takeda, Seiji; Sasaki, Toshihisa; Ochiai, Toru; Watanabe, Masatoshi; Kimura, Hideo
JAEA-Research 2008-046, 62 Pages, 2008/03
The Atomic Energy Commission of Japan states that the transuranium waste and uranium waste are to be disposed of by either near surface disposal without artificial barrier (trench disposal), near surface disposal with artificial barrier (concrete vault disposal), or intermediate depth disposal, depending on the radionuclides and their radioactivity concentration in the wastes. The ranges of radioactivity concentration for these different disposal concepts are, therefore, required to be determined for the regulation. The radioactivity concentration limits define the upper bound of radioactivity concentrations for licensing application of the disposal of radioactive waste. This document summaries the concept and method for estimation of the radioactivity concentration limits for concrete vault disposal of transuranium and uranium wastes, and provides the derived values of the radioactivity concentration limits for each radionuclide in the wastes.
Takeda, Seiji; Sasaki, Toshihisa; Sawaguchi, Takuma; Ochiai, Toru; Kimura, Hideo
JAEA-Research 2008-045, 60 Pages, 2008/03
This document summaries the concept and method (scenario selection, model/code description and parameter selection) for estimation of the radioactivity concentration limits for intermediate depth disposal of transuranium and uranium wastes, and provide the derived values of the radioactivity concentration limit for each radionuclide in the wastes. The values for the transuranium waste are published in a Nuclear Safety Commission of Japan report.
Takeda, Seiji; Watanabe, Masatoshi; Sawaguchi, Takuma; Sasaki, Toshihisa; Ochiai, Toru; Kimura, Hideo
JAEA-Research 2008-044, 64 Pages, 2008/03
This document summaries the concept and method (scenario selection, model/code description and parameter selection) for estimation of the radioactivity concentration limits for trench disposal of transuranium and uranium wastes, and provide the derived values of the radioactivity concentration limit for each radionuclide in the wastes. The values for the transuranium waste are published in a Nuclear Safety Commission of Japan report.
Sasaki, Toshihisa; Watanabe, Masatoshi; Takeda, Seiji; Sawaguchi, Takuma; Ochiai, Toru; Kimura, Hideo
JAEA-Data/Code 2008-003, 29 Pages, 2008/02
In this report, external effective dose conversion factors necessary for examining the activity concentration limits are derived for three disposal concepts. After this, the activity concentration limits that constitute a permissible range of radioactive concentration to typical land disposal concept (for radioactive wastes containing transuranic nuclides from reprocessing and MOX fuel manufacturing and uranium waste from enrichment and fuel manufacturing) are calculated. External effective dose conversion factors are derived in consideration with analysis that conforms to laws that use the conversion coefficients of ICRP Publication 74 for effective dose conversion, and adoption of the latest data i.e. -ray's and X-ray's energies and intensities of "JAERI-Data/Code 2001-004" as photon energy data. This document summarizes calculation method, conditions, and results of external effective dose conversion factors for transuranium and uranium wastes disposal.
Kimura, Hideo; Takeda, Seiji; Sasaki, Toshihisa; Ochiai, Toru
no journal, ,
no abstracts in English
Sawaguchi, Takuma; Takeda, Seiji; Sasaki, Toshihisa; Ochiai, Toru; Watanabe, Masatoshi; Kimura, Hideo
no journal, ,
no abstracts in English