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Journal Articles

Safety handling characteristics of high-level tritiated water

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:18 Percentile:20.89(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 $$gamma$$-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.

Journal Articles

Development of dose assessment code for accidental tritium releases; ACUTRI

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.

Journal Articles

Re-emission of heavy water vapour from soil to the atmosphere

Yokoyama, Sumi; Noguchi, Hiroshi; Ichimasa, Yusuke*; Ichimasa, Michiko*

Journal of Environmental Radioactivity, 71(3), p.201 - 213, 2004/01

 Times Cited Count:10 Percentile:74.97(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 H$$_{2}$$O, 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.

JAEA Reports

ACUTRI: A Computer code for assessing doses to the general public due to acute tritium releases

Yokoyama, Sumi; Noguchi, Hiroshi; Ryufuku, Susumu*; Sasaki, Toshihisa*; Kurosawa, Naohiro*

JAERI-Data/Code 2002-022, 87 Pages, 2002/11

JAERI-Data-Code-2002-022.pdf:4.26MB

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.

Journal Articles

Numerical modelling and laboratory experiments of tritium transport in unsaturated soil

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

Journal Articles

A One-dimensional dynamical soil-atmosphere tritiated water transport model

Yamazawa, Hiromi

Environmental Modelling & Software, 16(8), p.739 - 751, 2001/12

no abstracts in English

Journal Articles

Deposition of tritiated water vapour to water surface in outdoor field

Noguchi, Hiroshi; Fukutani, Satoshi*; Yokoyama, Sumi*; Kinouchi, Nobuyuki

Radiation Protection Dosimetry, 93(2), p.167 - 172, 2001/00

 Times Cited Count:6 Percentile:53.94(Environmental Sciences)

no abstracts in English

Journal Articles

Deposition of HTO to water surface during a chronic HT release experiment

Noguchi, Hiroshi; Fukutani, Satoshi*; Yokoyama, Sumi; Kinouchi, Nobuyuki

KURRI-KR-61, p.18 - 25, 2000/00

no abstracts in English

Journal Articles

Numerical study on soil-atmosphere tritiated water transfer

Yamazawa, Hiromi

KURRI-KR-61, p.100 - 105, 2000/00

no abstracts in English

Journal Articles

Measurement of HTO permeability parameters of materials for protective appliances

Yokoyama, Sumi; Noguchi, Hiroshi; Kinouchi, Nobuyuki; Yamamoto, Hideaki; Kato, Shohei; *; *

Hoken Butsuri, 34(1), p.57 - 66, 1999/00

no abstracts in English

Journal Articles

Reemission of heavy water deposited on a soil

Yokoyama, Sumi

Purazuma, Kaku Yugo Gakkai-Shi, 73(12), P. 1354, 1997/12

no abstracts in English

Journal Articles

Radiation effects and safety control of tritium, IV-5; Dose assessment model and parameter

Noguchi, Hiroshi; Yokoyama, Sumi

Nippon Genshiryoku Gakkai-Shi, 39(11), p.931 - 933, 1997/00

no abstracts in English

Journal Articles

Overview of the 1994 chronic HT release experiment at Chalk River

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

Journal Articles

Tritium behavior on a cultivated plot in the 1994 chronic HT release experiment at Chalk River

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

Journal Articles

Conversion of tritium gas to tritiated water in air

Noguchi, Hiroshi

Fusion Technology, 27(2T), p.56 - 61, 1995/03

no abstracts in English

JAEA Reports

JAEA Reports

Journal Articles

Effect of hydrogen isotope composition on conversion of low concentration tritium gas to tritiated water in air

Noguchi, Hiroshi; Murata, Mikio

Nippon Genshiryoku Gakkai-Shi, 33(4), p.360 - 362, 1991/04

 Times Cited Count:2 Percentile:46.69(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Tritium distribution ratios between the 30% tributyl phosphate(TBP)-normal dodecane(nDD) organic phase and uranyl nitrate-nitric acid aqueous phase

Fujine, Sachio; Uchiyama, Gunzo; Sugikawa, Susumu; Maeda, Mitsuru; Tsujino, Takeshi

JAERI-M 89-152, 14 Pages, 1989/10

JAERI-M-89-152.pdf:0.48MB

no abstracts in English

26 (Records 1-20 displayed on this page)