[en] Purpose: To reduce the quantity of radioactive waste produced by decontamination without decreasing the decontaminating effect due to the conventional electrolytic polishing method. Method: An electrolytic tank is filled with electrolyte of aqueous sodium chloride solution, metal treating material adhered with radioactice metal oxide and pair electrodes are dipped in the solution, and a current is flowed with the metal treating material as an anode. Part of the electrolyte is continuously removed by pump, and the sludge containing contaminated material and metal treating material hydroxide are isolated via a filter. After heavy metal ions are selectively adsorbed to an oxine added active charcoal. The filtrate is fed to the active charcoal, and is then returned to the tank to be reused. (Seki, T.)

[en] Purpose: To reduce the corrosion damages to the materials after the re-start of a nuclear power plant. Constitution: Water washing is continued till the specific conductivity of water washing liquid after chemical decontamination for the nuclear plant is reduced to less than 2 μsec/cm. This can reduce the corrosion damages to the same level as that under the usual reactor water conditions. (Yoshino, Y.)

[en] For confirming the critical conditions and comprehending the behaviors of plasma, it is essential to measure and calculate the various parameters of plasma, especially the temperature and density of ions and electrons, and radiation losses. Herein represented are the outline of the measuring devices manufactured for Japan Atomic Energy Research Institute and that for the Plasma Physics Laboratory of Kyoto University, together with the CAMAC for data processing. (author)

No abstract available

[en] Ventilatory steady state measurement with ¹³³Xe, using Ventil-Con (Radx) and a large area scintillation camera (Searle, LFOV) combined with a mini-computer system (Shimadzu, Scintipac 230) was employed to evaluate regional pulmonary function of 94 patients with chronic obstructive lung disease (COLD), fibrosis, carcinoma and other lung diseases. In the patients with COLD, mean washout times (anti t) were markedly prolonged in whole lung fields (anti m 130 +- 33 sec.) and ventilation indices (V*/V) (*: radical) and perfusion indices (Q*/V) (*: radical) were reduced in regional zones, especially in bilateral lower lung zones. For the patients with lung fibrosis, anti t values were short and the distribution of ventilation indices were uniform, and in contrast perfusion indices were reduced in the lower lung fields. In the area most affected by carcinoma, lung volumes (V) were reduced in parallel with the regional ventilation (V*) (*: radical) and perfusion (Q*) (*: radical). As the tumor approached the hilum, the relative ventilation and perfusion of cancerous side decreased remarkably in patients with obstructive findings on bronchoscopy. The mean washout times (anti t) for ¹³³Xe, calculated by a modified height over area method without background subtraction, were significantly longer than indicated by the data yielded by the least squares curve fitting of initial washout curve after background subtraction. Although the accuracy of these data was limited, it appeared that the prolonged anti t is a good parameter of regional ventilatory disturbance because significant correlations were found between the whole lung anti t in patients with lung diseases and their FEV 1.0% r = -0.66, RV/TLC r = 0.64, % TLC r = 0.43, PaCO₂ r = 0.41, PaO₂ r = -0.35. (author)

[en] Isotope shifts of 9 transitions from the ground and metastable states in Yb_I were measured for 7 stable isotopes with A = 168-176 by means of atomic-beam laser spectroscopy. Hyperfine constants A and B of 12 levels for ¹⁷¹Yb and ¹⁷³Yb were determined. Reliable values of nuclear parameters λ were obtained and changes in mean square nuclear charge radii δ< r²> were deduced using both the two-parameter model and the numerical calculation. Deformations for Yb stable isotopes were discussed. Hyperfine constants A and B were analyzed with the effective operator procedure and the single-electron hyperfine parameters of 6s and 6d electrons were derived for the Yb_I 4f¹⁴6s6d configuration. For the ³D_J and ¹D₂ states of 4f¹⁴6s6d, J and term dependences of isotope shifts were obtained and the parameters of the crossed-second-order effect were derived to be z_6d/λ = 18(6) MHz/fm² and g₂ (6s, 6d)/λ = -1120(60) MHz/fm². (author)

[en] The CAMAC system is attracting attention as a standard module for measurement and control. It is an interface capable of processing a large amount of data with high speed and is used mainly in the field of nuclear physics. Toshiba now has developed CAMAC modules and its software which have a microcomputer for the nucleus, and established quality assurance through simulation tests, environmental tests, etc. Application of this CAMAC to the measurement and control systems in nuclear fusion plants is now under promotion along with the development of the module series. (author)

[en] Atomic spectra of neutral praseodymium (Pr I) have been measured by means of the atomic-beam laser spectroscopy. Hyperfine structures of 34 atomic transitions in the wavelength range from 544 nm to 596 nm were resolved and hyperfine constants A and B were determined for 57 levels. Out of them, 18 transitions were found to be new ones and the energies and the electronic total angular momenta of 11 fine structure levels were determined for the first time. (author)

[en] The environmental radiation monitoring system supplied to Fukui Prefecture measures the dose of the environmental radiation and the weather items at ten locations in the outskirts of a nuclear power station, monitors these data at the central control station, carries out tabulation, CRT display, board display and data transfer. In order to improve the working ratio and the reliability of the system, both the computer and the data collecting system are duplicated, and countermeasures are taken against power supply failure. (auth.)

[en] To obtain information of core-support carbon material for VHTR, thermal conductivity and electrical resistivity of three domestic carbon blocks were measured. Results indicated the need for development of carbon material with lower thermal conductivity for VHTR. These two were also measured of the samples heat-treated between 1000⁰C and 3040⁰C for one hour. Thermal conductivity increased with heat-treatment above 1200⁰C and resistivity stayed constant between 1500⁰C and 2000⁰C. The results should be useful in choosing the final heat-treatment temperature in carbon material production. The changes of Lorentz number with heat treatment were classified into three heat-treatment temperature regions of below 1500⁰C, 1500⁰C - 2500⁰C, and above 2500⁰C; the results are interpreted with a graphitization model. (author)