Susumu Kitani

Adsorption of Krypton and Xenon on Various Adsorbents

The noble gases, krypton and xenon, were adsorbed on three kinds of molecular-sieves (AW-500, 5A and 13X), as well as on activated charcoals (Tsurumi-HC-30, Takeda-G, -L), at pressures from 10-2mmHg to 1 atm at temperatures ranging from —78—, 0— to 25°C. The adsorption isotherms of krypton and xenon on MS-5A and −13X are linearly proportional to pressure, and are considered to follow de Boer type isotherms. However, the isotherms for other adsorbents are shown to follow the Langmuir pattern. All the isotherms are discussed in terms of functions of the heat of adsorption and surface area. The adsorbents, that show the Langmuir isotherm pattern, are considered to be efficient for practical use in removing or recovering noble gases.

Measurement of particle sizes by higher order tyndall spectra (θ1 method)

Abstract Particle size measurements by higher order Tyndall spectra have been developed. In a previous experiment it was found that the first angle, θ1, which is measured from the direction of propagation of the incident beam, of red spectra of higher order Tyndall spectra is related to the average particle size, r (1). These relations have been discussed from the theoretical standpoint. The average radius of a monodisperse aerosol consisting of spherical particles can be evaluated by measuring θ1 from the following equation independent of refractive index except for the value of 2.0:log ( θ 10 ) + 1.43 log (10r) = 1.43, where θ1 is in degrees of angle and r in microns.

Preparation of monodisperse aerosols of dioctyl phthalate by a new apparatus

Abstract Dioctyl phthalate aerosols, of narrow size distribution with the logarithmic standard deviation of 0.08–0.12 over the range of particle diameter of 0.3–1.0 μ, were prepared reproducibly by means of an improved Sinclair-La Mer generator. The dependence of the size distribution on the generating conditions was studied in detail. The size distribution of the aerosol is independent of the temperature of the reheater when it is kept higher than that of the vaporizer. A satisfactorily uniform aerosol is prepared only if the flow rate of a carrier gas is kept lower than about 1 l/min. The particle size becomes larger with increasing vaporizer temperature and decreasing flow rate. The modal diameter D of the aerosol for the present apparatus is given as: D 3 = C exp ( −ΔH RT ) , where T is the vaporizer temperature, ΔH the latent heat of evaporation of the liquid, and C a constant depending on flow rate, number concentration of nuclei, and other functions.

Removal of Methyl Iodide by Impregnated Charcoals from Flowing Air under Humid Condition

The trapping of methyl iodide from flowing humid air by impregnated charcoals was studied with regard to chemical reactions between methyl iodide and impregnants. Twenty-seven compounds for impregnation on activated charcoal were tested. Stannous iodide and potassium thiocyanate were found to be the most effective, as well as potassium iodide and riethylenediamine, for the removal of methyl iodide in flowing steam-air systems. The characteristics of the base material for impregnation and the surface properties of the impregnated charcoals are also discussed.

Performance of Containment Sprays for Light Water Reactors and Evaluation of the Heat Transfer

Capacity curves, spray distributions, and droplet size distributions of light water reactor (pressurized water reactor (PWR) and boiling water reactor (BWR)) containment spray nozzles are obtained, and the heat removal effectiveness is evaluated by a computer program CONDENSE. It is revealed by the calculations that spray droplets from a PWR spray nozzle always attain the containment atmosphere temperature and spray droplets from a BWR spray nozzle attain the containment atmosphere temperature above approximately 70/degree/C. 16 refs.

Behavior of Sodium Oxide Aerosol in a Closed Chamber

The behavior of sodium oxide aerosol in a closed chamber was studied for the safety analysis of a Na-cooled fast reactor. The experimental apparatus and techniques are first described. The aerosol was released during a short time by blowing air onto heated Na in a 1 m3 chamber. The maximum mass concentration of the aerosol in the form of Na2O ranged of 0.05 ∼ 10g/m3. The particle size distribution, the aerosol mass concentration and the mass deposition rates were measured as a function of time. It was found that the mass median diameter of the aerosol was related to the maximum mass concentration. To determine the character of the behavior of sodium oxide aerosol in the chamber, the density of the aerosol material and the thickness of the boundary layer through which the particles deposit on the chamber wall were observed. The initial half-time of the aerosol mass concentration was compared with the values numerically calculated under certain assumptions.

Determination of size distribution of small aerosol particles by light-scattering method

Abstract The size distribution of small aerosol particles was determined by measuring the intensity of scattered light at three angles for a fixed wavelength of the incident beam. A pair of relative intensities of scattered light at the angles θ and π-θ to that at the angle π/2 were calculated as a function of the modal size and logarithmic standard deviation. Charts of the relative intensities of scattered light showed the possibility of determination of the particle sizes of aerosol less than 0.3 μm in modal diameter. The experimental results obtained from the theoretical charts for dioctyl phthalate aerosol were compared with those from the polarization ratio method. It was found that the parameters for the characterization of aerosol particle size were in good agreement between the two methods.

Preparation of monodisperse aerosols of sodium chloride.

Abstract This paper described a modification of a generator for the preparation of sodium chloride aerosols of narrow size distribution. The aerosols, consisting of spherical particles, can be generated by two-stage homogeneous nucleation. The size distribution has been determined from the polarization ratio of the scattered light by assuming that the particle size distribution follows a log normal frequency curve. The experimental conditions for the preparation of a monodisperse aerosol have been studied.

Iodine removal tests for BWR containment spray by large scale facility.

Iodine removal tests for a BWR containment spray were carried out with large-scale JAERI Model Containment Test Facility under LOCA simulated conditions. The tests consisted of two groups: “gas-phase based” tests mainly to obtain the initial iodine removal rate by the spray and “liquid-phase based” tests to obtain the iodine partition coefficient at equilibrium state. It was shown that the degree of iodine removal was largely influenced by pH-value of spray water. The results were discussed with calculated results by a code MIRA-PB using a dose reduction factor for the airborne iodine.

Determination of the number concentration of aerosol particles by light scattering method with an efficient device

Abstract For the measurements of the angular intensities of scattered light of aerosol, an ingenious method without the aid of a cell with glass windows was devised. The number concentrations of dioctyl phthalate aerosol can be precisely determined from the Rayleigh ratio using the working standard method, without affecting refraction and reflection at the glass-air interface. The present method is compared with the method using the glass cell in the Rayleigh ratio.