[en] This report discusses the practical approach to thorium utilization which might be effective to solve principle energy problems. Until now, the basic obstacle for a thorium fuel cycle was a need for a closed system. The technical advantages of a molten salt system are described

[en] A design and research program is discUssed of the development of accelerator molten-salt breeder (AMSB) consisting of a proton accelerator and a molten fluoride target. The target simultaneously serves as a blanket for fissionable material prodUction. An addition of some amoUnt of fissile nuclides to a melt expands the AMSB potentialities as the fissionable material production increases and the energy generation also grows up to the level of self-provision. Besides the blanket salts may be used as nuclear fuel for molten-salt converter reactor (MSCR). The combined AM SB+MSCR system has better parameters as compared to other breeder reactors, molten-salt breeder reactors (MSBR) included

[en] In the determination of the energy and the entropy for the vacancy-solute binding by means of quenched-in resistivity measurements in dilute aluminum alloys, several problems are involved and these are discussed by the authors. (Auth.)

[en] The annealing kinetics of vacancies in deformed metals can experimentally be described by the Harper form as C=C₀exp(-Ktsup(m)), where t is the time and C₀ is the initial vacancy concentration. The value of the exponent m is about 1/2, but values larger than 1/2 have also been reported. The annealing kinetics of vacancies in deformed gold have been examined with resistivity measurements, and the results are discussed with the simulation by a Monte Carlo method. (Auth.)

[en] Hydrogen and oxygen behavior in a sodium test loop similar to the sodium-cooled fast breeder reactor were examined. Hydrogen partial pressure equilibrated to the sodium was measured by a membrane-permeation-type hydrogen-meter. An electrochemical oxygen-meter was used to determine the oxygen activity. The measured hydrogen pressure was converted to the hydrogen concentration through the Sieverts' constant, and the oxygen activity was also converted to the oxygen concentration through the characteristics of the oxygen-meter cells. Hydrogen and oxygen solubilities in liquid sodium were obtained as functions of the cold-trap temperature from 115 to 208⁰C. Both data have a similar temperature dependence and were anomalously larger than the extrapolated values in the temperature region lower than 180⁰C. At 300⁰C, the addition of hydrogen to the liquid sodium, valved off from the purification apparatus, lowered the oxygen activity in the liquid sodium. The experimental results suggest a significant interaction between hydrogen and oxygen and the existence of (OH) species in liquid sodium. Using the solubility data of oxygen, hydrogen, and (OH) species, the free energy change of the reaction, (O)/sub in Na/ + (H)/sub in Na/ = (OH)/sub in Na/, was obtained and was ΔG⁰(kcal/mole) = -28 + 0.043 T. From the temperature dependence of the equilibrium hydrogen pressure, the apparent heat of a solution of hydrogen in liquid sodium was obtained as 1.6 kcal/mole

No abstract available

[en] The water quality control as well as the improvement of component materials and structure of support plates of SG has been promoted lately, but it would also be significant to hold a chemical cleaning technology as a maintenance technology enabling the improvement of water-related environment of the secondary side of SG by chemical cleaning. From a point of view, we developed a low-temperature iron solvent with non-sulfur (non-S) inhibitors added and a low-odor copper solvent. (author)

[en] The interaction between self-interstitial(I) and solute(S) atoms has been examined in electron-irradiated gold: (a) The radiation-induced resistivity rapidly increases for solutes that differ from the solvent in atomic size by more than 20%. (b) Undersized solutes such as Cu and Ni interact strongly with self-interstitial atoms, and show two distinct substages connected with a long plateau in stage II, which are responsible for the dissociation of IS → I + S and I₂S → I₂ + S, whose energies are about 0.3 and 0.5 eV, respectively. (c) Oversized solutes such as Sb and Sn increase markedly the amount of recovery in stage II, and in particular Pb with an extraordinarily large atomic size has specific trapping configurations different from other oversized solutes. (author)

[en] Effects of small amounts of impurities on recovery and damage production in gold wire specimens 0.5 mm thick irradiated with 6 MeV electrons have systematically been investigated mainly by electrical resistivity. Among fifteen elements studied in this experiment, impurities such as Sb, Pb, Sn, Cd, Zn, Cu and Mn have fairly large interaction with interstitials, while Sn and Mn show particular interaction with vacancies

[en] The KEK electron/positron injector linac provides a short-pulse electron beam with an energy of 2.5 GeV for the Photon Factory (PF) storage ring, that with an energy of 3 GeV for the Advanced Ring (PF-AR) for pulse X-rays, and single-bunch electron and positron beams with energies of 8 and 3.5 GeV respectively for the KEK B-Factory (KEKB) storage rings. A trigger-timing signal distribution system of the injector linac was newly developed and extended for stable injection to the KEKB rings with the required injection-timing accuracy highly stabilized to less than 30 ps in root mean square because the old trigger system distributed the trigger-timing signals for the injection to the PF ring and the PF-AR with an injection-timing accuracy of 300 ps. In this report the design and its performance of the new trigger-timing signal distribution system are described in detail