[en] Purpose: To enable optimul and automatic control of the water level in a reactor even when a feedwater control system is operated in a manual mode, such as, at the start, stop and the recovery operation after a scram of the reactor. Constitution: A water level control device for a nuclear reactor is composed of a computer and an analog memory, plant signals from a reactor water level detector, a reactor pressure detector, a feedwater pump discharge pressure detector and a drain water flow rate detector are collected, and the openings of the feedwater control valve and the drain control valve are calculated. Further, the openings of the feedwater control valve and the drain control valve are controlled based on the calculated result, and the water level in the reactor is properly maintained. At this time a communication valve to a condenser remains opened. (Sekiya, K.)

[en] Purpose: To safely control the steam-pressure of a BWR-type reactor while monitoring the rate of change of the temperature of the coolant. Constitution: The steam-pressure of nuclear reactor is automatically controlled by controlling the amount of steam dumped to a condenser under the control of the opening of bypass valve of a turbine to maintain the limiting value of the rate of change of the coolant temperature while monitoring the coolant temperature rate. That is, a reactor pressure signal detected by a pressure detector is sent to a reactor pressure controlling device, the rate to change of the temperature of the coolant is calculated and output to a turbine pressure controller; thus the reactor pressure is safely controlled. (Yoshihara, H.)

[en] Purpose: To enhance the reliability of a reactor abnormality diagnosing system by diagnosing reactor abnormality with the difference between the average deviation of a nuclear power plant from a model, and the true deviation, thereby eliminating a drift even if the drift of the deviation of the plant normal time occurs, and inhibiting an error alarm for the plant abnormality. Constitution: Signals from a nuclear power plant and a model are input to first subtractor. The output from the first subtractor is input to a drift operational circuit, which thereby obtains the average predetermined unit times of the deviations between the nuclear power plant and the model. Then, a second subtractor subtracts the output from the first subtractor from the output of the drift operational circuit, and applies the subtracted output to a threshold circuit, which thereupon diagnoses reactor abnormality. (Yoshino, Y.)

No abstract available

[en] We applied the X-ray standing wave method to the determination of the Sb position in atomic-layer-doped Si crystal. From the fitting of the calculated with the experimental results, an extension of 0.03 and a coherent ratio of 86 % were obtained. (author)

[en] Interference of two beams resonantly scattered in an X-ray interferometer has been demonstrated. The interference arises between the beams emitted by different nuclei with some time interval. High visibility interference oscillations show the coherent superposition, as well as the complete coincidence of these beams in the time domain. (author)

[en] The intensity correlation experiment in a visible light made by Hanbury Brown and Twiss is extended to that in X-rays. Correlations in 14.4 keV X-ray photons from a synchrotron radiation source are observed by the coincidence counting technique. High brilliance of synchrotron radiation available in the TRISTAN Main Ring enables the observation of two-photon correlations with a reasonable measurement time. (author)

[en] From 1968 to 1976, 31 patients underwent breast conservation surgery (tumorectomy) and irradiation. A review of the available pathologic slides has revealed that 11 of that number had definite breast cancer. Of these 11 patients, three experienced a relapse, one with local recurrence only, and two with distant metastasis, though one of these two also had a local recurrence. The patient manifesting a local recurrence only was salvaged by a mastectomy, while the other two with distant metastases have died. Survival and disease-free survival in these 11 patients were at least equal to the results of other Japanese patients of the same aged and stages who had undergone a halsted operation during the same period. As for the other 20 patients, either their pathologic slides were not available, or their diagnosis was equivocal or benign. None suffered a relapse. Cosmetic results were excellent in most patients, and there were no second malignancies in the treatment volume. (author)