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Journal Articles

Feasibility study on the blanket tritium recovery system using the palladium membrane diffuser

Kawamura, Yoshinori; Enoeda, Mikio; Yamanishi, Toshihiko; Nishi, Masataka

Fusion Engineering and Design, 81(1-7), p.809 - 814, 2006/02

 Times Cited Count:16 Percentile:70.51(Nuclear Science & Technology)

Tritium bred in the solid breeder blanket of a fusion reactor is extracted by passing of a helium sweep gas. Tritium is separated from sweep gas at the blanket tritium recovery system. Palladium membrane diffuser is one of the applicable processes for the blanket tritium recovery system. It is usually applied for hydrogen purification system such as TEP in ITER. However, it has been reported that the rate controlling step changes at lower hydrogen pressure such as the blanket sweep gas condition, and discussion about application for the blanket sweep gas condition is not enough. Recently, conceptual design of the demonstration reactor, named "DEMO2001", has been proposed from JAERI. In this report, the application of the Pd diffuser for the blanket sweep gas condition is discussed based on the condition of DEMO 2001.

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

Tritium recovery from solid breeder blanket by water vapor addition to helium sweep gas

Kawamura, Yoshinori; Iwai, Yasunori; Nakamura, Hirofumi; Hayashi, Takumi; Yamanishi, Toshihiko; Nishi, Masataka

Fusion Science and Technology, 48(1), p.654 - 657, 2005/07

 Times Cited Count:4 Percentile:29.01(Nuclear Science & Technology)

Adding some amount of hydrogen to the helium sweep gas is effective for tritium extraction from blanket, but it causes permeation of tritium to a cooling system. In the design study of a demonstration reactor in JAERI, tritium leakage has been estimated to be about 20% of bred tritium under typical sweep gas conditions. If these tritiums are recovered under the ITER-WDS condition, tritium leakage limitation has to be less than 0.3% of typical case. Water vapor addition to the sweep gas is effective not only for blanket tritium extraction but also for permeation prevention. The reaction rate of isotope exchange is larger than the case of H$$_2$$, and the equilibrium constant is also expected to be about 1.0. When the H/T ratio is 100, tritium inventory of breeder material is larger than the case of H$$_2$$ addition. However it is not so large. In case of H$$_2$$O sweep, separation of tritiated water from helium seems to be easyer, but the process that changes HTO to HT is necessary.

Journal Articles

Simulation of tritium spreading in controlled areas after a tritium release

Cristescu, I. R.*; Travis, J.*; Iwai, Yasunori; Kobayashi, Kazuhiro; Murdoch, D.*

Fusion Science and Technology, 48(1), p.464 - 467, 2005/07

 Times Cited Count:3 Percentile:23.09(Nuclear Science & Technology)

A model to simulate tritium behaviour after a release into a confined ventilated volume has been developed. The model assumes that for the investigated cases, tritium behaviour can be characterized by solving the dynamic equations of motion (the compressible Navier-Stokes equations) coupled with the classical k-$$varepsilon$$ turbulence model to simulate the ventilation in the room and mass diffusion for tritium spreading. The GASFLOW-II fluid dynamics field code, developed through a Los Alamos National Laboratory (LANL) - Forschungszentrum Karlsruhe co-operation, was used as the computational tool to solve the equations that describe the processes. The numerical results have been validated with experimental data collected on the experimental facility (Caisson) at the Tritium Process Laboratory (TPL) Japan. Additionally an investigation of the influence of the obstacles to the tritium distribution inside the Caisson is presented.

JAEA Reports

Development of sealing plug for sweep gas line

Kikuchi, Taiji; Yamada, Hirokazu*; Saito, Takashi; Nakamichi, Masaru; Tsuchiya, Kunihiko; Kawamura, Hiroshi

JAERI-Tech 2004-026, 28 Pages, 2004/03

JAERI-Tech-2004-026.pdf:2.06MB

Iirradiation capsule for irradiation test of tritium breeder and inner capsule for pebble bed of tritium breeder is inserted. Post irradiation examination of tritium breeder will be performed after irradiation test. On cutting of irradiation capsule, sweep gas line should be sealed to prevent the tritium gas release or inflow of water to sweep gas line. However, general valve and plug cannot apply to sweep gas line sealing because of the effect of neutron irradiation or limited space in irradiation capsule. Therefore, sealing plug for sweep gas line sealing has to be developed. This report shows the development of sealing plug for sweep gas line sealing and operating procedure of sealing plug in irradiation capsule.

Journal Articles

Tritium experience in JT-60 operation

Oikawa, Akira; Miya, Naoyuki

Purazuma, Kaku Yugo Gakkai-Shi, 78(12), p.1308 - 1312, 2002/12

Tritium experience over decade in DD operation of JT-60 is summarized.Effluent of tritium in vacuum exhaust through the stack to environment always remains a level below detectable levels. Tritium concentration of drain is also below the limit of regurations of the local agreement amd the law. For a scheduled maintenance work of the in-vessel components, following an annual deuterium plasma discharge campaign, a 4-week no-deuterium plasma discharge campaign and the succeeded ventilation by room air allow to reduce tritium concentration on the surface of in-vessel components. A cooperative endeavour is underway for analysis of tritium behavior in JT-60.

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.

JAEA Reports

A Database on tritium behavior in the chronic HT release experiment, 1; Meteorological data and tritium concentrations in air and soil

Noguchi, Hiroshi; Yokoyama, Sumi; Fukatani, S.*; Kinouchi, Nobuyuki; Murata, Mikio; Amano, Hikaru; Atarashi-Andoh, Mariko

JAERI-Data/Code 99-022, 125 Pages, 1999/03

JAERI-Data-Code-99-022.pdf:6.76MB

no abstracts in English

Journal Articles

A Steady-state simulation model of gas separation system by hollow-filament type membrane module

Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka

Journal of Nuclear Science and Technology, 36(1), p.95 - 104, 1999/01

 Times Cited Count:12 Percentile:66.16(Nuclear Science & Technology)

no abstracts in English

Journal Articles

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

Noguchi, Hiroshi; Yokoyama, Sumi

Nihon 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

Conversion of tritium gas to tritiated water in air

Noguchi, Hiroshi

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

no abstracts in English

Journal Articles

Estimation of HT gas diffusion coefficient and conversion rate constant of HT gas to HTO in intact soil

Murata, Mikio; Noguchi, Hiroshi

Nihon Genshiryoku Gakkai-Shi, 34(2), p.149 - 152, 1992/02

 Times Cited Count:2 Percentile:41.58(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Study on voloxidation process for tritium control in reprocessing

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

Radioact. Waste Manage. Nucl. Fuel Cycle, 17(1), p.63 - 79, 1992/00

no abstracts in English

Journal Articles

Development of in-situ gas analyzer for hydrogen isotopes in fusion fuel gas processing

Okuno, Kenji; ; Ohira, Shigeru; Naruse, Yuji

Journal of Nuclear Science and Technology, 28(6), p.509 - 516, 1991/06

no abstracts in English

Journal Articles

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

Noguchi, Hiroshi; Murata, Mikio

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

 Times Cited Count:2 Percentile:50.00(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Outline of an experimental apparatus for the study on the advanced voloxidation process

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

JAERI-M 90-016, 71 Pages, 1990/02

JAERI-M-90-016.pdf:1.88MB

no abstracts in English

Journal Articles

Recoil tritium reaction in rare gas-ethane solid mixtures at ultralow temperature

K.W.Lee*; ; ; ; ; ; Saeki, Masakatsu; Tachikawa, Enzo

J.Phys.Chem., 90, p.5343 - 5347, 1986/00

no abstracts in English

Journal Articles

22 (Records 1-20 displayed on this page)