JPH05297180A - Light monitoring device in reactor containment - Google Patents

Abstract

PURPOSE:To allow a reliable measurement in a reactor containment, a higher intelligence for light output, possession of self-diagnostic function, and judgment of quality of signal by conducting the transmission and detection of signals in the container by use of an optical cable and a light outputting measuring instrument. CONSTITUTION:A number of equipments necessary for vapor generation are received in a container 8, and a number of signals are present therein. For example, a recirculating pump motor 11 has a vibrometer 5 and a winding thermometer 2, and a pressure vessel 7 has a number of thermometers 2. A release valve 13 also has a limit switch 6, a valve has the thermometer 2, and a drain sump 12 has a level instrument 4, and the atmospheric temperature is measured by the thermometer 2. In this way, many equipments and signals are present, these are detected by light, and the signals are transmitted to a monitor plate 9 to give an instruction or alarm, whereby the stable operation of a plant is assisted. Considering the ensuring of the space for the transmission of many signals and a reduction in cost, many optical couplers 14 are used to conduct the time-divided signal transmission, whereby the signal processing according to a requirement can be performed.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] Cable penetration is required for transmission from the inside to the outside of many electric meter devices in the reactor containment vessel. By passing an optical signal through this cable penetration, The signal can be transmitted by light.

As a result, the temperature of each part in the storage container is
Not only is it detected using an optical fiber detector, but the output of all other measuring instruments (water level, etc.) is also output by light, so the operating status inside the container can be monitored, and even more stable operation is possible Expected to be used.

[0003]

2. Description of the Related Art Conventionally, many control and instrumentation signals are contained in a reactor containment vessel, one control cable and one instrumentation cable are laid for each target device, and a cable suitable for the purpose is used. Through penetration, it was transmitted to the necessary signal transmission destination outside the container.

In this case, a large number of cables and a large number of cable penetrations are required, resulting in a large construction cost and a great impact on the process.

Further, the number of signal detection points is one signal for each detector, and many atmospheric thermometers are required.

[0006] Further, even if an erroneous signal is generated, the other measuring instruments cannot be put in the container, so that it is not possible to judge whether it is a malfunction or a normal signal.

By adopting this method, the number of ambient temperature detection points becomes innumerable, reliable measurement in the container becomes possible, and other detectors can be made intelligent for optical output, and self-diagnosis is possible. A function can be provided, and it is possible to judge the quality of the signal.

[0008]

In the transmission of signals with the control instrumentation equipment in the reactor containment vessel, one signal was conventionally laid as about one cable, so many cables and many cable penetrations were carried out. Was needed.

To further improve the operability of a nuclear power plant,
Even in the unlikely event of a failure, it is necessary to make multiple measurements and determine if it is a true failure or a measurement error and take appropriate measures. Improving measurement reliability is especially important.

To solve this problem, multiple measurement is the most important, but as described above, the cost increase and the impact on the construction process are large, and the increase in cables and the like makes the space inside the container narrower and the equipment difficult to use. turn into.

Therefore, an optical cable is used to measure the temperature, and the output of the instrument for optical output is also used as the cable of the optical thermometer to prevent an increase in conventional cables and cable penetrations.

Further, in order to improve reliability in measuring instruments other than temperature (water level, flow rate, vibration, position, etc.), a self-diagnosis function can be added by making each measuring instrument intelligent.

At this time, the optical cable is more vulnerable to mechanical damage than the conventional cable. Therefore, the optical cable is put in a pipe and laid under the beam to improve the work.

Further, if even the current measuring instruments are made light, further reduction effect can be expected.

[0015]

[Means for Solving the Problems] The problem is solved by transmitting a signal in a storage container using an optical cable.

That is, the temperature can be measured with the optical cable.

The temperature of the reflection point can be measured by injecting a pulse from one end of the optical cable and measuring the specific light (Raman scattered light) of the reflected light after a certain time.

At this time, the measurable temperature is measured as an average value of a length of 1 m corresponding to the time determined by this limit by performing pulse emission and identification in time division.

Therefore, by laying the optical cables evenly in the reactor containment vessel, it is possible to measure the temperature of the entire interior of the vessel.

Therefore, even more points can be measured with a smaller number of cables (at least one) than the conventional temperature measuring points (about 170 points not for BWR).

At this time, it is unsuitable for the installation route to be a grid pattern, such as obstruction of passage, so that the space factor is improved by preferentially utilizing the under beam of the corridor.

At this time, multiple measurement can be performed by increasing the number of optical cables.

The other instruments are made intelligent and have an optical output, thereby self-diagnosing the instruments and improving the reliability of measurement.

Further, as described in claim 4, it is possible to use the optical coupler for both the optical cable thermometer and the optical cable, whereby the space factor can be improved.

[0025]

[Action]

 (1) Measure the ambient temperature with an optical cable at a pitch of 1 m.

Since the number of measurement points in the reactor containment vessel can be greatly increased, the reliability of temperature measurement can be improved.

(2) Measuring temperature with an optical cable is a general-purpose technique.

Since an optical cable having improved radiation resistance is used, it is not general-purpose.

Furthermore, for long-term use, by laying the inside of the pipe that is soft (due to the cable route configuration), it can be used even in a large radiation deterioration area.

(3) Multi-core optical cable.

A general optical cable is not single-core but multi-core.
(6 cores). Therefore, multiple measurements can be performed by using two of them.

Furthermore, by using another optical output measuring device,
When made intelligent, the remaining 4 cores can be used, and the 2 cores for temperature measurement can also be used as a star coupler for transmission.

(4) Optical cable penetration required.

A cable penetration that accommodates an optical cable is adopted.

[0035]

[Example] When the monitoring system is multiplexed, the number of cables and cable penetrations increases, and the construction process is extended.
There are also disadvantages in plant construction, such as increased space restrictions and increased possibility of leakage from the containment vessel due to increased cable penetration.

In order to prevent this, it is necessary to work to reduce cables and cable penetration.

For this reason, an embodiment will be shown in which the following merits are utilized.

FIG. 1 shows a system diagram of an apparatus intended to measure and transmit a large number of signals in a storage container by using an optical cable and to reduce the number of optical cables by using an optical coupler.

The nuclear power plant has a containment vessel 8 in which a pressure vessel 7 containing fuel is placed.

A large number of devices necessary for steam generation are housed in the storage container, and a large number of signals are present.

For example, reference numeral 11 is a recirculation pump motor having a vibration meter 5 and a winding thermometer 2. Further, the pressure vessel 7 is provided with a large number of thermometers 2.

The relief valve 13 is also provided with a limit switch 6 for opening and closing the valve.

The valve 3 is provided with a thermometer 2 for detecting the leaf.

The drain sump 12 is provided with a level meter 4.

The ambient temperature is measured by the thermometer 2.

As described above, a large number of devices and signals exist and these are detected by light, and the signals are transmitted to the monitoring panel 9 in the storage container via the optical cable penetration 10, and signal processing is performed to give instructions and alarms. To help the stable operation of the plant.

At this time, there is a method of individually transmitting a large number of signals, but in consideration of securing a space and cost reduction, a large number of optical couplers 14 are used to perform time division signal transmission.

FIG. 2 shows the same monitoring device in which the optical cable is passed through a bendable pipe 15 in order to facilitate cable exchange when the optical cable is deteriorated by radiation irradiation.

As a result, since the optical cable can be replaced in a short time, it is possible to reduce the radiation exposure of the worker.

FIG. 3 shows the entire corridor (radial beam) 16 in the storage container.

This corridor constitutes a floor beam in a containment vessel with a steel frame, and a grating 17 is mounted on this to form a floor. An optical cable will be laid under this beam.

FIG. 4 is an enlarged view of the situation A section.

FIG. 5 shows a connection example of the optical cable according to the present invention.

That is, the optical cable 1 for temperature measurement is laid in various places to measure the temperature around it, and the optical coupling ring 14 is provided on the way to provide a large number of nearby signals (E1 to Em).
Connect 18

The monitoring board 9 outside the storage container receives the temperature signal and other signals 18 which are connected to the optical cable 1 through the optical cable penetration 10 and passed through the optical coupler 14 in a time division manner, and perform necessary signal processing.

[0056]

By taking out the signal in the reactor containment vessel by using the optical cable and the optical signal detector, it is possible to secure the space by reducing the cable and perform the signal processing as required.

Also, by mounting the conventional instrument multiplex,
Multiple measurements with different principles are possible, which improves the reliability of the plant.

At this time, if the temperature is measured with the optical cable,
Since multi-point signals can be obtained, temperature distribution can be measured.

If an optical cable is put in a pipe under the corridor and installed, the communication can be secured and the optical cable can be replaced in a short time.

[Brief description of drawings]

FIG. 1 is a system diagram of an optical monitoring device in a reactor containment vessel.

FIG. 2 is a system diagram showing an example in which a pipe is installed to facilitate replacement of an optical cable.

FIG. 3 is a plan view showing an example in which an optical cable is attached below a corridor.

FIG. 4 is an enlarged perspective view of a part of FIG.

FIG. 5 is an explanatory diagram of a connection state of the optical cable of the present invention.

[Explanation of symbols]

1 ... Optical cable for temperature measurement, 2 ... Optical thermometer, 3 ... Valve, 4
… Optical water level gauge, 5… Optical vibrometer, 6… Optical limit switch,
7 ... Pressure vessel, 8 ... Storage vessel, 9 ... Monitoring panel, 10 ... Optical cable penetration, 11 ... Recirculation pump motor,
12 ... Drain sump, 13 ... Relief valve, 14 ... Optical coupler.

Claims (4)

[Claims] 1. An optical monitoring device in a nuclear reactor containment vessel for transmitting and detecting a signal in the nuclear reactor containment vessel by using an optical cable and an optical output measuring instrument. 2. A device for transmitting and detecting a signal in a reactor containment vessel using an optical cable or an optical output measuring device, which is intended to deteriorate the optical cable due to radiation, and periodically replaces the optical cable. The optical monitoring device inside the containment vessel is characterized in that an optical cable is laid inside a flexible pipe so that it can be operated. 3. An apparatus for transmitting and detecting a signal in a reactor containment vessel using an optical cable or a measuring instrument for optical output, in a corridor in the vessel for preventing damage to the optical cable. An optical monitoring device inside a nuclear reactor containment vessel, which is installed under the beam. 4. An apparatus for transmitting and detecting a signal in a reactor containment vessel using an optical cable or an optical output measuring device, wherein the optical cable used as a temperature measuring detector is a signal of another optical output measuring instrument. An optical monitoring device in a reactor containment vessel, which is also used as a transmission line and is monitored by an optical signal.