Doryokuro Kakunenryo Kaihatsu Jigyodan

Fujikura Limited

Yokogawa Electric Works, Ltd.

Koichiro Nakamoto

Nobumi Ohyama

Takashi Tsumanuma

Kazuo Sanada

Osamu Fukuda

Sadao Chigira

Hiroshi Rindo

Kuniaki Ara

Kiyokazu Ishii

Kiyoshi Adachi

Hajime Kuwahara

An optical fiber includes light-transmitting means comprising at least one optical fiber element, and a heat-resistant and radiation-resistant coating formed around the light-transmitting means. The coating comprises an inner buffer layer formed around the light-transmitting means and an outer layer of polyether ether ketone formed around the inner layer.

Heat and radiation resistant optical fiber

A method for monitoring flow condition of a liquid metal which employs a detector consisting of an excitation coil applied with an a.c. current and at least two detection coils disposed on both sides of said excitation coil. The detector is disposed in the flowing direction of the liquid metal and a peak point of the cross-correlation function of fluctuation signals occurring in said detection coils is examined. By detecting the moving direction, the polarity and the magnitude of the peak point, the flow condition can be comprehensively ascertained, such as a change in flow velocity, a change in void fraction, the presence of voids and transit velocity of void.

Method for monitoring flow condition of liquid metal

A detector to be inserted into a flowing conductive fluid, e.g. sodium coolant in a nuclear reactor, comprising at least one exciting coil to receive an a-c signal applied thereto and two detecting coils located in the proximity of the exciting coil. The difference and/or the sum of the output signals of the detecting coils is computed to produce a flow velocity signal and/or a temperature-responsive signal for the fluid. Such flow velocity signal or temperature signal is rectified synchronously by a signal the phase of which is shifted substantially .+-. 90.degree. with respect to the flow velocity signal or temperature signal, thereby enabling the device to detect voids in the flowing fluid without adverse effects from flow velocity variations or flow disturbances occurring in the fluid.

Void detecting device

Growing community of inventors

Mito, Japan

Koichiro Nakamoto