Kenji Muta

Experimental Apparatus for the Fuel Cleanup Process in the Tritium Process Laboratory

At the Tritium Process Laboratory (TPL) in the Japan Atomic Energy Research Institute, an apparatus for the Fuel Cleanup Process was designed, fabricated and installed for the experiments with up to 1g of tritium. The function of the system is continuous processing of a simulated plasma exhaust and separation of hydrogen isotopes and impurity elements in it. Main components are, palladium diffusers, catalytic reactors, cold traps, an electrolysis cell and zirconium-cobalt beds. The apparatus was installed in a glovebox and tested with hydrogen by early 1988.

Hydrogen isotope separation characteristics of cryogenic distillation column

Abstract Cryogenic distillation is a promising method for a hydrogen isotope separation system in the fuel cycle of nuclear fusion reactors. However, sufficient experimental information has not yet been obtained to enable us to achieve the cascade operation of cryogenic distillation columns. The present study aims to obtain such information. The experimental apparatus used in the present study is composed of a cryogenic distillation column, gas chromatographs and a helium refrigerator. The cryogenic distillation column can be operated in three modes; the total reflux mode, the total recycle mode and the total recycle mode with a feedback stream. In each experiment, the gas in the condenser and the gas or liquid in the reboiler are sampled and analyzed with gas chromatographs after the column pressure, the pressure drop in the packed section, and other operating conditions reach a steady state. The experimental results are arranged with the pressure drop in the packed section and the height equivalent to a theoretical plate (HETP). As a result of the total reflux experiments, it should be noted that the pre-flooding operation of the distillation column before the total reflux operation improves the separating efficiency of the distillation column and reduces the HETP value. The experimental results also show that the pressure drop increases with vapor velocity. The flooding point or the loading point is not observed with vapor velocity lower than 20 cm/s. As a result of the total recycle experiments, the HETP value is observed to decrease with reflux ratio.

Experimental Appratus for Cryogenic Hydrogen Isotope Separation Process in the Tritium Process Laboratory

An experimental apparatus for the development of cryogenic hydrogen isotope separation system (ISS) was designed and fabricated at the Tritium Process Laboratory (TPL) in Japan Atomic Energy Research Institute (JAERI). This apparatus will serve to study the separation characteristics of hydrogen isotope mixture with 10/sup 4/ Ci of tritium. It consists of two distillation columns with isotopic equilibrators for H-D-T mixtures and can be operated with both single column distillation mode and two interlinked cascade modes. Installation of this system in a glovebox was completed by late January, 1988. Tests with tritium will start late 1988.

Detection of nitrogen oxides by high-resolution near-infrared absorption spectroscopy

Near-infrared absorption spectra of NO, NO2 and N2O were observed in the wavelength region between 1.2 and 1.9 micrometers using a high-resolution Fourier-transform spectrometer, and we have obtained precise absorption data which are useful for tunable diode laser absorption spectroscopy (TDLAS). Furthermore, the NO and N2O were detected by means of TDLAS method for the first time using InGaAs-DFB diode lasers which were designed to access absorption lines at wavelengths of 1.798 and 1.766 micrometers respectively.

Simultaneous detection of oxygen and soot particles by visible diode laser absorption spectroscopy

A technique for simultaneous detection of oxygen molecules and soot particles by means of visible tunable diode laser absorption spectroscopy was investigated. The effects of solid particles on the measurement of oxygen molecules were evaluated using a 760 nm visible diode laser. The maximum solid particle density was 5.6g/m3m, allowing measurement of the concentration of oxygen with sufficient precision. We applied this technique to analysis of real exhaust gas from a large-scale test furnace, and verified that oxygen molecules and soot particles in such gas can be directly measured from a large-scale test plant without pretreatement, such as removal of water vapor and soot.