Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Yorimasa Endo

Toshiki Fukushima

Yasuo Suzuki

Osamu Nishiyama

Shimpey Shirayama

Ichiro Tai

Akira Yunoki

Noriyuki Seki

Mitsuo Ishibashi

Toshiaki Itoh

Eiji Seki

Eiji Noda

Keiichi Chiba

A pipe switching unit switches connections between the radiation monitor side and a plurality of sampling pipes which are installed in different sampling places to introduce air from the respective sampling places. An intermittent dust radiation monitor collect, in a dust collection section, dust in the air introduced through each sampling pipe sequentially switched by the pipe switching unit, and measures the radioactivity concentration of dust in the dust collection section. A continuous dust radiation monitor collects, in a dust collection section, dust in the air introduced through a fixed sampling pipe switched by the pipe switching unit, and measures the radioactivity concentration of dust in the dust collection section. With this arrangement, while intermittent measurement is performed in normal operation as in the prior art, the intermittent measurement is switched to continuous measurement, as needed, thereby improving the measurement precision.

Dust radiation monitor apparatus and dust sampling apparatus used therefor

A wide range monitor apparatus for the output from a nuclear reactor has a logarithmic count rate measuring circuit and a Campbel measuring circuit corresponding to different neutron flux density ranges of the neutron flux output from a neutron detector. The apparatus monitors the nuclear reactor output as a single output which has a linearity with the neutron flux density over a wide range thereof. A logic circuit combines two comparison discrimination signals obtained by comparing low and high comparison voltages corresponding to the hysteresis width in an overlap region of the outputs from the two measuring circuits with detection output voltages from the two measuring circuits. One of the outputs from the two measuring circuits is selected in accordance with the logical level signal obtained by combining the two comparison discrimination signals by the logic circuit.

Wide range monitor apparatus for output from nuclear reactor

A preamplifier for a wide range neutron flux monitoring system is disclosed. The preamplifier contains first to fifth amplifiers and a selection switch. The first amplifier for high frequency band amplification has a low input impedance circuit. The second amplifier for low frequency band amplification has a high input impedance circuit. Either of the first and second amplifiers can provide a path for the neutron flux level signal derived from a detector according to the frequency of the neutron flux level signal. The third amplifier (pulse amplifier) amplifies the output signal of the first amplifier and transfers the amplified signal to a pulse signal counting system. The lower frequency band Campbell signal is applied to the Campbelling system, through the second amplifier, the fourth amplifier (low frequency band Campbelling amplifier), and the selection switch. The higher frequency band Campbell signal is applied to the Campbelling system, through the first amplifier, the fifth amplifier (high frequency band Campbell amplifier), and the selection switch.

Preamplifier for a wide range neutron flux monitoring system

Growing community of inventors

Tokorozawa, Japan

Yorimasa Endo