Hitachi, Ltd.

Hitachi-ge Nuclear Energy, Ltd.

Izumi Yamada

Fuminobu Takahashi

Shunsuke Uchida

Haruo Fujimori

Takaharu Fukuzaki

Jun Ozawa

Hiroshi Yamada

Tokio Yamagiwa

Fumihiro Endo

Masahiro Koike

Youichi Ohshita

Hashime Nagai

Mitsuo Sawairi

Hajime Yamamoto

Makoto Nagase

Atsushi Baba

Yoshinori Musha

Hidefumi Ibe

Satoshi Ogura

Atsushi Fushimi

Akira Murata

Tamotsu Asano

Ryuta Hama

Mikio Koyama

Mikiyasu Tsunashima

Hiroaki Katsuyama

An ultrasonic reactor water level measuring device and an evaluation method are provided and prevent a reduction in the measurement accuracy of a water level that is in a wide measurement range. The ultrasonic reactor water level measuring device includes an upper tube extending from a gas phase portion in a reactor, a lower tube extending from a liquid phase portion in the reactor, measurement tubes connected to each other and arranged at multiple stages between the upper tube and the lower tube, and units for generating and receiving ultrasonic waves, the units being arranged at bottom portions of the measurement tubes. The ultrasonic reactor water level measuring device measures levels of water within the measurement tubes and calculates a water level within the reactor from the sum of the measured water levels, the sum excluding an overlapped part of the measurement tubes.

Ultrasonic reactor water level measuring device and evaluation method

Plant operating conditions 1, apparatus operating conditions 2 and environment conditions 3 are accumulated, combined and put together as a set of plant status variables 8 through a monitor 6, while water chemistry information 4 is accumulated as another set of plant status variables 9. The set of status variables 8 is updated and the past data are accumulated in the set of status variables 9. Periodical inspection data 5 are also accumulated in the set of status variables 9 along with the water chemistry information 4. The set 9 is compressed and stored as a plant chart 11 such as a personal clinical chart. A status variable prediction 12 is performed in consideration of the personality of a plant. Both data of the sets 8 and 10 are compared with each other by comparison means 13. If both the data nearly coincide with each other, the plant is diagnosed to the normal and, if not, it is diagnosed to be abnormal. When the plant is diagnosed to abnormal, an abnormal apparatus and an abnormal factor are identified.

Plant monitoring and diagnosing method and system, as well as plant

A diagnosis system having sensors for supervising a plant, signal processors for processing signals of the sensors, and a state quantity arithmetic operation unit. The state quantity arithmetic operation unit calculates a quantity of state expressing the environment of the plant on the basis of supervisory information inputted through the signal processors. A state quantity prediction unit predictively calculates a quantity of state after a predetermined time on the basis of the quantity of state, supervisory information and a time change of the quantity of state inputted through the state quantity arithmetic operation unit. A future event prediction unit predicts a future event on the basis of predicted information of the quantity of state inputted through the state quantity prediction unit. An image information processor converts the quantity of state given by the state quantity arithmetic operation unit into image information and indicates the image information on a display unit. An image information processor converts the predicted quantity of state after the predetermined time, given by the state quantity prediction unit, into image information and indicates the image information on a display unit. An image information processor converts the future event predicted by the future event prediction unit into image information and indicates the image information on a display unit.

Diagnosis system

Plant operating conditions 1, apparatus operating conditions 2 and environment conditions 3 are accumulated, combined and put together as a set of plant status variables 8 -through a monitor 6, while water chemistry information 4 is accumulated as another set of plant status variables 9. The set of status variables 8 is updated and the past data are accumulated in the set of status variables 9. Periodical inspection data 5 are also accumulated in the set of status variables 9 along with the water chemistry information 4. The set 9 is compressed and stored as a plant chart 11 such as a personal clinical chart. A status variable prediction 12 is performed in consideration of the personality of a plant. Both data of the sets 8 and 10 are compared with each other by comparison means 13. If both the data nearly coincide with each other, the plant is diagnosed to be normal and, if not, it is diagnosed to be abnormal. When the plant is diagnosed to be abnormal, an abnormal apparatus and an abnormal factor are identified.

An abnormality diagnosing system and method for high voltage power apparatus wherein a plurality of detectors for detecting abnormalities of the high voltage power apparatus and providing outputs indicative thereof are disposed to detect predetermined phenomena indicative of at least an insulation abnormality, power supply abnormality, and foreign matter among abnormalities existing inside of the high voltage power apparatus. A monitoring arrangement responsive to the outputs of the detectors provides at least one of an output and display of the kind of abnormality detected.

Abnormality diagnosing system and method for a high voltage power

An abnormality diagnosing system and method for high voltage power apparatus wherein a plurality of detectors for detecting abnormalities of the high voltage power apparatus and providing outputs indicative thereof are disposed to detect predetermined phenomena indicative of at least an insulation abnormality, power supply abnormality and foregin matter among abnormalities existing inside of the high voltage power apparatus. A monitoring arrangement responsive to the outputs of the detectors provides at least one of an output and display of the kind of abnormality detected.

Disclosed is a picture display apparatus connected to a low resolution ultrasonic inspector so as to display a picture with high resolution. In the apparatus, an approximate spectrum of a theoretical spectrum representing an object having a known shape as a reference and a spectrum obtained through measurement of the known-shaped object are subject to Fourier transformation so that a transfer function of a measurement device is calculated from the ratio between the respective values obtained through the two operations of Fourier transformation, whereby an unknown shape of an object is displayed on the basis of the transfer function and Fourier transformation values of a measured spectrum of the object having the unknown shape. A modified Gaussian distribution obtained by combining two Gaussian distributions, in which the transformation values of the spatial spectrum of the known shape are reduced in a high frequency range and in which oscillations are less spread in the high frequency range, is employed as the approximate spectrum of the theoretical spectrum representing the known-shaped object, so that the high frequency components of the spatial spectrum of the unknown shape can be reduced and therefore a clear picture can be displayed with high resolution.

Picture display apparatus

A sensor for monitoring the interior of a sodium-cooled fast breeder reactor comprises a pair of symmetrical magnetic cores, a magnetostrictive or piezoelectric vibrator element bonded to one of the cores, a primary coil and a plurality of secondary coils surrounding the magnetic cores, and a container enclosing the above members. The primary coil applied with an exciting alternating current generates an acoustic signal voltage indicative of sound, if any, originated in the interior of the reactor. The magnetic flux produced by the exciting current is influenced by the temperature and flow velocity of sodium flowing around the sensor, and corresponding voltage signals resulting from the changed magnetic flux are induced in the secondary coils.

Reactor in-vessel sensor and core monitoring apparatus

Disclosed is a sodium ionization detector (SID) for detecting sodium leaks by detecting the magnitude of fluctuation of the ion current produced by thermally ionizing sodium. There is a particular relationship between the magnitude of fluctuation of the ion current and the concentration of sodium. The sodium ionization detector is adapted to determine the magnitude of fluctuation of the ion current so as to compare it with a predetermined value. The magnitude of fluctuation of the ion current is determined, for example, by the root-mean-square value of a fluctuation component of the ion current.

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Ibaraki-ken, Japan

Izumi Yamada