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Hayashi, Takumi; Ito, Takeshi*; Kobayashi, Kazuhiro; Isobe, Kanetsugu; Nishi, Masataka
Fusion Engineering and Design, 81(8-14), p.1365 - 1369, 2006/03
Times Cited Count:19 Percentile:76.64(Nuclear Science & Technology)In a fusion reactor, high-level tritiated water of more than GBq/ml will be generated and stored temporally in the various areas. High level tritiated water decomposes by itself and generates hydrogen and oxygen, and becomes to tritiated hydrogen peroxide water, however, effective G-values from tritiated water are different from those obtained -ray experiments in our previous report. Furthermore, tritiated water of about 250GBq/ml has been stored for several years safely and checked its characteristics. Using the above experiences, this paper summarizes safety requirements for storage of high-level tritiated water and discusses design issues of the safety storage system. Concerning gaseous species, storage tank should be maintained at negative pressure and purged periodically or constantly to dedicated tritium removal system. Specially, it is important that the G-value of high-level tritiated water is increasing with decreasing the tritium concentration. The pH and ORP (Oxidation Reduction Potential) of tritiated water have been also changed depending on the tritium concentration and maintained for more than several years in glass vessel. High-level tritiated water of more than GBq/ml was acid and became to be corrosive depending on the dissolved species. Large amount of tritiated water will be stored in the various tanks of stainless steel, therefore, it should be monitored so that the liquid situation is maintained not to be corrosive.
Yokoyama, Sumi; Noguchi, Hiroshi; Kurosawa, Naohiro*
Hoken Butsuri, 40(4), p.376 - 384, 2005/12
A computer code named ACUTRI has been developed to assess tritium doses due to inhalation to the general public. ACUTRI can calculate the radiological impact of tritium gas (HT) and tritiated water (HTO) released accidentally to the atmosphere. The models in this code consist of a tritium transfer model including the oxidation of HT to HTO and the reemission of HTO from soil to the atmosphere and a dose calculation model. The atmospheric dispersion of the primary HT and HTO plumes and secondary HTO plume, which is reemitted from soil to the atmosphere, is calculated by using the Gaussian plume model. In this calculation, it is possible to analyze statistically on meteorology in the same way as a conventional dose assessment method according to the meteorological guideline of the Nuclear Safety Commission of Japan. Tritium concentrations in air and their resultant doses were calculated using the ACUTRI code under some conditions. In order to validate the model, calculations were compared with experimental results.
Yokoyama, Sumi; Noguchi, Hiroshi; Ichimasa, Yusuke*; Ichimasa, Michiko*
Journal of Environmental Radioactivity, 71(3), p.201 - 213, 2004/01
Times Cited Count:11 Percentile:23.92(Environmental Sciences)The reemission process of tritiated water (HTO) deposited on a soil surface is an important process to assess tritium doses to the general public around nuclear fusion facilities. A field experiment using heavy water (HDO) as a substitute for HTO was curried out in the summertime to investigate the reemission process of HTO from soil to the atmosphere. In the experiment, the time variations of the depth profiles of HDO concentrations in soil exposed to HDO vapour and soil mixed with HDO were measured during the reemission process on the field. The decrease of HDO concentration insoil water of exposed soil was much greater than that of mixed soil. The reemission process was analysed using a model including the evaporation of HDO from soil, the exchange between the soil HDO and air HO, and the diffusion of HDO in soil. It was found that the model is applicable to calculating the time variations of detailed depth profiles of HDO concentration in soil water in surface soil layers.
Yokoyama, Sumi; Noguchi, Hiroshi; Ryufuku, Susumu*; Sasaki, Toshihisa*; Kurosawa, Naohiro*
JAERI-Data/Code 2002-022, 87 Pages, 2002/11
Tritium, which is used as a fuel of a D-T burning fusion reactor, is the most important radionuclide for the safety assessment of a nuclear fusion experimental reactor such as ITER. Thus, a computer code, ACUTRI, which calculates the radiological impact of tritium released accidentally to the atmosphere, has been developed, aiming to be of use in a discussion on licensing of a fusion experimental reactor and an environmental safety evaluation method in Japan. ACUTRI calculates an individual tritium dose based on transfer models specific to tritium in the environment. A Gaussian plume model is used for calculating the atmospheric dispersion of tritium gas (HT) and/or tritiated water (HTO). The environmental pathway model in ACUTRI considers the following internal exposures: inhalation from a primary plume (HT and/or HTO) released from the facilities and inhalation from a secondary plume (HTO) reemitted from the ground following deposition of HT and HTO. This report describes an outline of the ACUTRI code, a user guide and the results of test calculation.
Koarashi, Jun*; Iida, Takao*; Atarashi-Andoh, Mariko; Yamazawa, Hiromi; Amano, Hikaru
Fusion Science and Technology, 41(3), p.464 - 469, 2002/05
no abstracts in English
Yamazawa, Hiromi
Environmental Modelling & Software, 16(8), p.739 - 751, 2001/12
no abstracts in English
Noguchi, Hiroshi; Fukutani, Satoshi*; Yokoyama, Sumi*; Kinouchi, Nobuyuki
Radiation Protection Dosimetry, 93(2), p.167 - 172, 2001/00
Times Cited Count:7 Percentile:48.13(Environmental Sciences)no abstracts in English
Noguchi, Hiroshi; Fukutani, Satoshi*; Yokoyama, Sumi; Kinouchi, Nobuyuki
KURRI-KR-61, p.18 - 25, 2000/00
no abstracts in English
Yamazawa, Hiromi
KURRI-KR-61, p.100 - 105, 2000/00
no abstracts in English
Yokoyama, Sumi; Noguchi, Hiroshi; Kinouchi, Nobuyuki; Yamamoto, Hideaki; Kato, Shohei; ;
Hoken Butsuri, 34(1), p.57 - 66, 1999/00
no abstracts in English
Noguchi, Hiroshi
Purazuma, Kaku Yugo Gakkai-Shi, 74(7), p.712 - 715, 1998/07
no abstracts in English
Yokoyama, Sumi
Purazuma, Kaku Yugo Gakkai-Shi, 73(12), P. 1354, 1997/12
no abstracts in English
Noguchi, Hiroshi; Yokoyama, Sumi
Nihon Genshiryoku Gakkai-Shi, 39(11), p.931 - 933, 1997/00
no abstracts in English
Noguchi, Hiroshi; Yokoyama, Sumi; Kinouchi, Nobuyuki; Murata, Mikio; Amano, Hikaru; Atarashi, Mariko; Ichimasa, Yusuke*; Ichimasa, Michiko*
Fusion Technology, 28, p.924 - 929, 1995/10
no abstracts in English
P.A.Davis*; W.J.G.Workman*; B.D.Amiro*; F.S.Spencer*; Noguchi, Hiroshi; Amano, Hikaru; Ichimasa, Yusuke*; Ichimasa, Michiko*
Fusion Technology, 28, p.840 - 845, 1995/10
no abstracts in English
Noguchi, Hiroshi
Fusion Technology, 27(2T), p.56 - 61, 1995/03
no abstracts in English
Murata, Mikio; Kinouchi, Nobuyuki; Yokoyama, Sumi
JAERI-M 94-065, 93 Pages, 1994/03
no abstracts in English
Maekawa, Fujio; Maekawa, Hiroshi
JAERI-M 93-017, 53 Pages, 1993/02
no abstracts in English
Noguchi, Hiroshi; Murata, Mikio
Nihon Genshiryoku Gakkai-Shi, 33(4), p.360 - 362, 1991/04
Times Cited Count:2 Percentile:50.60(Nuclear Science & Technology)no abstracts in English
Fujine, Sachio; Uchiyama, Gunzo; Sugikawa, Susumu; Maeda, Mitsuru; Tsujino, Takeshi
JAERI-M 89-152, 14 Pages, 1989/10
no abstracts in English