Showing papers by "Japan Atomic Energy Research Institute published in 1986"
TL;DR: In this paper, a geometric-progression (G-P) method formula, Br = 1 + (B − 1) · (Kx − 1)/(K − 1), accurately represents the buildup factor data as a function of distance for the following reasons:
Abstract: A geometric-progression (G-P) method formula, Br = 1 + (B − 1) · (Kx − 1)/(K − 1), accurately represents the buildup factor data as a function of distance for the following reasons:1. The value of ...
243 citations
TL;DR: In this article, new experimental steels were designed and tested as the reduced activation alternatives to the current austenitic and ferritic prime candidate alloys for applications to the first wall structural components of Tokamak reactors.
154 citations
TL;DR: In this article, the authors used the Wallis-type correlation (J g * 1/2+mJ i *1/2=C) to determine the CCFL characteristics of air-water and saturated steam-water flow in hot legs of PWRS.
Abstract: In order to determine the Counter-Current Flow Limitation (CCFL) in hot legs of PWRS, CCFL characteristics of air-water and saturated steam-water flow were experimentally investigated in a modeled flow path of a horizontal tube connected to an inclined riser. The ranges of dimensions of experimental tubes were as follows: diameter D 0.026–0.076 m, length of horizontal tube H 0.01–0.4 m, length of inclined riser I 0.038–0.6 m and inclination angle of inclined riser θ 40° or 45°. Wallis-type correlation (J g *1/2+mJ i *1/2=C) was applicable to the data during a steady separated flow. An analysis based on envelope theory showed that the constant C should be a function of H/D and I. A function of C with those parameters was empirically determined by using data obtained in this study. The developed function correlated well with the results of Richter et al. (D = 0.203 m, H = 1.26 m, I = 0.5 m and θ = 45°). The constant m in the Wallis-type correlation was almost constant 0.75. The problems were discussed, whic...
89 citations
TL;DR: In this article, a brief review of the experimental results of the hydrostatic pressure effect on the lock-in transitions in various tetramethylammonium tetrahalogenometallic compounds, {N(CH3)4}2XY4 (X: Mn, Fe, Co, Ni, Cu, Zn; Y: Cl, Br).
Abstract: A brief review is given for the experimental results of hydrostatic pressure effect on the lock-in transitions in various tetramethylammonium tetrahalogenometallic compounds, {N(CH3)4}2XY4 (X: Mn, Fe, Co, Ni, Cu, Zn; Y: Cl, Br). The pressure-temperature phase diagrams of the chloride compounds with X = Mn, Fe, Co, Zn can be arranged in a unified reduced p-T phase diagram. Detailed observations are described as to the stabilization of the ferroelectric phase in the p-T space for the -MnCl4, -FeCl4, and -ZnCl4 compounds. The phase transition in the -ZnBr4. -MnBr4, and -CoBr4 compounds corresponds to the high pressure state in the chloride compounds. The deuteration effect on the phase transitions at high pressure is discussed.
85 citations
TL;DR: A fibrous adsorbent containing amidoxime groups (AOF) for recovering uranium from seawater was synthesized by the radiation-induced grafting of acrylonitrile (AN) to a fiber followed by the amidoximation of cyano groups of poly(AN) graft chains as mentioned in this paper.
Abstract: A fibrous adsorbent containing amidoxime groups (AOF) for recovering uranium from seawater was synthesized by the radiation-induced grafting of acrylonitrile (AN) to a fiber followed by the amidoximation of cyano groups of poly(AN) graft chains. When such hydrophilic monomers as N, N-dimethyl-acrylamide (DMAAm) and acrylic acid (AAc) were preliminarily grafted, both the water uptake and the mobility of the sorbed water in AOF were improved in the order: AOF-containing poly-(DMAAm) graft chains (AOF-DMAAm) > AOF-containing poly(AAc) graft chains (AOF-AAc) > AOF without hydrophilic graft chains. The uranium uptake with these adsorbents was, on the other hand, in the order: AOF-AAc > AOF-DMAAm > AOF. The adsorption of alkaline earths was related to the distribution pattern of poly(AAc) graft chains inside the fiber. The adsorbed alkaline earths were eliminated from the adsorbent fiber by introducing a solution of heavy metal ions such as Cu2+.
67 citations
TL;DR: In this paper, the distribution of microorganisms in 15 samples of selected spices and the effects of irradiation of them were studied, and the total aerobic bacteria in black pepper, white pepper, turmeric, rosemary and basil were determined to be 3 × 103 to 5 × 107 per gram.
Abstract: The distribution of microorganisms in 15 samples of selected spices and the effects of irradiation of them were studied. The total aerobic bacteria in black pepper, white pepper, turmeric, rosemary and basil were determined to be 3 × 103 to 5 × 107 per gram. Coliforms were also determined in 8 samples to be 2 × 102 to 2 × 106 per gram. The main aerobic-spore-formers were identified as Bacillus pumilus and B. subtilis. Molds were determined in 10 samples to be 1 × 102 to 2 × 104 per gram which consisted mainly of the Aspergillus glaucus, A. restrictus, A. flavus, A. fumigatus, A. niger groups and Penicillium. A study on the inactivation of microorganisms in spices showed that gamma-irradiation doses of 1.2 to 1.5 Mrad were required to reduce the total aerobic bacteria to below a detectable level, while doses of below 1.0 Mrad were required to decrease the spore-forming bacteria to below 103 per gram, the Japanese hygenic standard. Goliforms were eliminated with 0.4 to 1.0 Mrad irradiation. In the storage s...
63 citations
TL;DR: An amidoxime-group-containing adsorbent for recovering uranium from seawater was made by radiation-induced graft polymerization of acrylonitrile onto polymeric fiber, followed by amidoximation.
Abstract: An amidoxime-group-containing adsorbent for recovering uranium from seawater was made by radiation-induced graft polymerization of acrylonitrile onto polymeric fiber, followed by amidoximation. Uranium adsorption of the adsorbent contacted with seawater in a column increased with the increase in flow rate, then leveled off. The relationship between uranium adsorption in a batch process and the ratio of the amount of seawater to that of adsorbent was found to be effective in evaluating adsorbent contacted with any amount of seawater. The conditioning of the adsorbent with an alkaline solution at higher temperature (80°C) after the acid desorption recovered the adsorption ability to the original level. This made it possible to apply the adsorbent to recycle use. On the other hand, the adsorbent conditioned at room temperature or that without conditioning lost adsorption ability during recycle use. The increase in water uptake was observed as one of the physical changes produced during recycle use o...
63 citations
TL;DR: In this article, the tritium produced in neutron-irradiated Li 2 O crystals was found to exist spreading over three different valence states of T +, T − and T 0.
58 citations
01 Jan 1986-International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes
TL;DR: The results show that the additions of polymers do not change the dose-response, although they increase the pre-dose ESR amplitude of the dosimeter to some extent.
53 citations
TL;DR: In this article, the authors investigated the validity and the error of the Bergles-Rohsenow correlation predicting the superheat at the onset of nucleate boiling in an upgraded JRR-3 fuel element.
Abstract: Experiments were carried out with a vertical rectangular channel simulating a sub-channel of the upgraded JRR-3 fuel element, in order to investigate the validity and the error of the correlations predicting the superheat at the onset of nucleate boiling. These correlations were used in the core thermal-hydraulic design of the upgraded JRR-3. As the results, the following were made clear: (1) The existing Bergles-Rohsenow correlation gives a good prediction for the relationship of heat flux vs. superheat at the onset of nucleate boiling, with the error of about 1 K against the lower limits of the measured superheat. (2) There are no significant differences in the characteristics of the relationship of heat flux vs. superheat at the onset of nucleate boiling between upflow and downflow. (3) There are no significant differences in the histories of relationship of heat flux vs. superheat from the forced convection single-phase flow to the subcooled boiling between increasing heat flux and decreasing heat flu...
41 citations
TL;DR: In this article, the isotope effects in the lithium amalgam formation were studied by using the mercury cathode and LiOH solutions, and it was found that the isotopic equilibrium was attained between the aqueous and the liquid amalgam phases.
Abstract: Isotope effects in the lithium amalgam formation were studied by using the mercury cathode and LiOH solutions. The electrolyses were carried out at different conditions of both applied voltages 4–10 V, and the concentrations of initially charged LiOH, 0.5–5 mol/dm3. Higher efficiency of electrolytic amalgam formation was observed at higher LiOH concentrations and higher applied voltages. At these conditions, however, significant amount of solid amalgam was produced in the mercury phase. From the isotopic analyses on the samples taken during the electrolyses, it was found that the isotopic equilibrium was attained between the aqueous and the liquid amalgam phases. The isotopic equilibrium constant (isotope separation factor) was determined as 1.056 (average value for all the experiments) at 20°C.
TL;DR: In this paper, the effects of electron beam irradiation on molecular motions were studied by measuring dynamic viscoelastic properties in the temperature range from − 160°C to 350°C.
TL;DR: In this article, the authors studied the thermal release behavior of tritium produced in neutron-irradiated γ-LiAlO2 (Li2O) crystals and determined the diffusion coefficient in the temperature range from 630 to 930 K, where probable errors were ± 1.0 kJ mol−1 for activation energy and ± 0.1 for the logarithm of preexponential term.
TL;DR: In this article, the combination effect of ionizing radiation and ozone to degrade humic acid in water was superior to ozone and radiation alone, and a chain reaction mechanism was suggested for the oxidation of Humic acid.
TL;DR: In this article, an in-situ tritium recovery experiment was conducted in the JRR-2 reactor on Li 2 O and LiAlO 2 spheres, and a technique for obtaining tritiam diffusion coefficients from the time dependency of trittium release after incremental temperature changes was developed.
TL;DR: In this paper, the phase relations of ZrO 2 Y 2 O 3 ε 3 ǫ Nd 2 O O 3 and CeO 2 systems have been studied at 1100 and 1600°C.
TL;DR: In this paper, chemical luminance analysis was used for determining the oxidation layer formed by the irradiation of polypropylene for medical supplies, and the degree of oxidation by irradiation with electron beam was very small; the intensity at the surface area was only one-third that for the γ-irradiated samples.
Abstract: Chemiluminescence (CL) analysis was used for determining the oxidation layer formed by the irradiation of polypropylene for medical supplies. The depth of the oxidation layer from the surface depended on dose rate and increased with decreasing dose rate. The oxidation occurred remarkably at a region near the surface area of the film where the diffusion of oxygen is more sufficient. On the contrary, there was very little oxidation in the interior portion. The oxidation layers of polypropylene samples irradiated with electron beam showed U-shaped profiles in the cross-section of film as did as a sample irradiated with γ-rays. However, the degree of oxidation by irradiation with electron beam was very small; CL intensity at the surface area was only one-third that for the γ-irradiated samples.
TL;DR: In this article, the authors reviewed and tabulated the radiative transition probabilities for the titanium ions Ti V to Ti XXII and presented Grotrian diagrams to provide a graphical overview.
TL;DR: In this article, microstructural developments on solution-annealed (SA) and cold-worked (CW) JPCA and U.S.-PCA were determined on the High Flux Isotope Reactor at 300 and 400°C.
TL;DR: In this article, the buildup factors and spectra of gamma rays including fluorescence radiations in lead are calculated using a discrete ordinates code, PALLAS-PL,SP-Br.
Abstract: Detailed calculations of the buildup factors and spectra of gamma rays including fluorescence radiations in lead are carried out using a discrete ordinates code, PALLAS-PL,SP-Br The exposure and a
TL;DR: The thermophilic fungus Sporotrichum cellulophilum was immobilized with nonwoven materials for cellulase production and the heat stability of the immobilized growing fungus was higher than that of the free fungus.
Abstract: The thermophilic fungus Sporotrichum cellulophilum was immobilized with nonwoven materials for cellulase production. The cellulose powder concentration in the medium was an important factor controlling cellulase production. When the cellulose powder concentration in the nonwoven materials was more than 4%, cellulase production was suppressed. The growth of the immobilized fungi depended on the spaces in the nonwoven materials. Immobilized growing fungi were retained by the non-woven materials, and the supernatant medium did not contain mycelia. The heat stability of the immobilized growing fungus was higher than that of the free fungus. The immobilized fungus gave the same FPA as the free mycelium, but the lag time for cellulase production in the immobilized fungus was longer. It was necessary for the only medium to be changed in order to get the immobilized growing fungus to continue producing cellulase. In this instance there was no difference of lag time in comparison with the free cells, and the supply of cellulose powder and polypepton was reduced to two-thirds. After 23 exchanges of the medium (2.6 mg cellulose powder/1 cm(3) nonwoven materials) FPA value was maintained. The periodic batch culture was continued for 69 days.
TL;DR: In this paper, the phase control of a loop antenna array is used to reduce impurity line emissions associated with the ion cyclotron range of frequency (ICRF) heating.
Abstract: Reduction of impurity line emissions associated with the ion cyclotron range of frequency (ICRF) heating is achieved by the phase control of a loop antenna array. Reduction in metal impurity emissions and radiation loss is closely correlated with the amount of power radiated from the antennae with parallel wave number near k∥ = 0. The maximum density attainable without disruption is increased over that in the Ohmic heating phase, by reduction of radiation loss.
TL;DR: Corrosion tests with Ni-base high temperature alloys were carried out at 900 and 950°C in simulated high temperature reactor helium environments, and it was shown that the carburization and decarburization behavior is strongly affected by the Cr and Ti (Al) contents of the alloys.
TL;DR: In this article, an experiment on oxidation of 304 stainless steel was performed in steam between 900°C and 1350°C, using the spare cladding of the reactor of the nuclear-powered ship Mutsu.
TL;DR: In this paper, the morphology of acrylic acid-grafted high-density polyethylene film and the distribution of poly(acrylic acid) in grafted film are examined, and the grafting was carried out in the acrylic acid aqueous solution with or without Mohr's salt (an inhibitor of homopolymerization) by preirradiation method.
Abstract: The morphology of acrylic acid-grafted high-density polyethylene film and the distribution of poly(acrylic acid) in grafted film are examined. The grafting was carried out in the acrylic acid aqueous solution with or without Mohr's salt (an inhibitor of homopolymerization) by preirradiation method. It has become clear that without Mohr's salt the grafted poly(acrylic acid) layer is formed on the surface of the film, while in the presence of Mohr's salt the grafting layer consisting both of poly(acrylic acid) and polyethylene is formed on the inside of the surface.
TL;DR: In this paper, U.S. and Japan have independently analyzed their own integral experiments using their own data base and codes, and compared their analytical predictions obtained by both countries are compared to measured values.
Abstract: Phase I integral experiments of U.S./JAERI Collaborative Program on Fusion Breeder Neutronics which are carried out at the Fusion Neutronics Source (FNS) facility at JAERI ranged from D-T neutron source characterization experiments, tritium production rate (TPR) measurements in a reference Li/sub 2/0 assembly, first wall experiments with and without coolant simulation and beryllium neutron multiplier experiments in various configurations. Both U.S. and Japan have independently analyzed these experiments using their own data base and codes. Analytical predictions obtained by both countries are compared to measured values. Results of this intercomparison is presented in this paper.
TL;DR: In this article, the Gibbs free energies of formation of Mo2C and WC were successfully measured from 1173 to 1573 K by keeping the moisture level in the system low enough not to oxidize the sample.
Abstract: The gas equilibrium method of CH4/H2 has been widely used for measuring carbon potential. However, it has been reported that this method is not applicable at high temperatures since the equilibrium between CH4 and H2 is disturbed by the reaction of CH4 with moisture in the system. Nevertheless, this method should be applicable theoretically at high temperatures below which CH4 decomposition can be neglected because the equilibrium between CH4 and H2 reaches constant ratio in spite of the reaction. Since the role of moisture is to oxidize the sample during the measurements under the oxygen potential determined byPh2o/ph2 ratio, the Gibbs free energies of formation of Mo2C and WC were successfully measured from 1173 to 1573 K by keeping the moisture level in the system low enough not to oxidize the sample. The experimental results are expressed by the following equations which were derived by least squares treatments of the data: Mo2C:ΔG = -68270 + 8.23T J mol-1 WC:ΔG = -52330 + 14.06T J mol-1 These values were in good agreement with those measured by M. Gleiseret al. for narrow tempareture ranges using the CO/CO2 gas equilibrium method.
TL;DR: Verification studies showed a good applicability of DISKET to reactor accident diagnosis, and programming language UTILISP, which is a dialect of LISp, is used to manipulate symbolic data effectively.
Abstract: An accident diagnostic system DISKET has been developed to identify the cause and the type of an abnormal transient of a nuclear power plant. The system is based on the knowledge engineering (KE) and consists of an inference engine IERIAS and a knowledge base. The main features of DISKET are the following: 1. Time-varying characteristics of transients can be treated. 2. Knowledge base can be divided into several knowledge units to handle a lot of rules effectively. 3. Programming language UTILISP, which is a dialect of LISP, is used to manipulate symbolic data effectively. For the verification of DISKET, performance tests have been conducted for several types of accidents. The knowledge base used in the tests was generated from the data of various types of transients produced by a PWR plant simulator. The results of verification studies showed a good applicability of DISKET to reactor accident diagnosis.