JPS58186089A - Reactor water level detecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a reactor water level detection device for detecting the water level of reactor water in a nuclear reactor pressure vessel.

[Technical background of the invention and its problems]

In nuclear reactor plants, the water level of reactor water in the reactor pressure vessel is constantly detected in order to ensure safe operation of the reactor. The water level may differ from the actual water level due to certain changes in flow rate, pressure, atmospheric temperature inside the reactor containment vessel, etc. Because the reactor water level is detected from the pressure difference at multiple positions with different heights within the liquid phase of the Mayu reactor pressure vessel, a leak occurred from the piping between the reactor pressure vessel and the detector. Detection errors also occur in these cases. If such an error occurs, there is a risk that the reactor control device, which operates in relation to the output of the detector, may malfunction.

[Purpose of the invention]

The present invention was made based on these circumstances,
The purpose of this is to eliminate detection errors caused by changes in reactor water process conditions by correcting them in accordance with changes in the process conditions, and to enable highly accurate detection of reactor water level. An object of the present invention is to provide a reactor water level detection device that can also monitor a detection system by comparing multiple detections @all.

[Summary of the invention]

The reactor water level detection device according to the present invention includes a plurality of sets of water level detectors that detect the reactor water level based on the differential pressure within the reactor pressure vessel, and a reactor water level detector provided correspondingly to each of the water level detectors. A plurality of process condition detection systems detect all changes in process conditions, and the detection results obtained from each of the water level detectors are corrected according to the process conditions of the reactor water based on the output of each of the process condition detection systems. A comparator that compares the outputs of multiple correction circuits and outputs an abnormality detection signal if there is a difference between the outputs, and an alarm that operates by inputting the abnormality detection signal from this comparator. Alarm and '1
It is equipped with t-3.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to all the drawings.

In FIG. 1, numeral 1 in the figure is a reactor pressure vessel in a boiling water nuclear reactor plant, and numeral 2 in the figure is a reactor containment vessel in which this reactor pressure vessel 1 is stored. A reactor core 3 is configured inside the reactor pressure vessel 1, and reactor water 4 is accommodated therein.

Around the shattered reactor core 3, there are jets, top pumps 5, etc., and recirculation pumps 61, 6 are installed outside the reactor pressure vessel 1.
B is placed. and for each recirculation pump 6, 6B
Therefore, the suction pipe 6A-1゜6B-1 and the discharge pipe 6A
-2, 6B-2, reactor water 4 circulates between the inside and outside of the reactor pressure vessel 1, and the jet number? f5... The entire reactor water 4 is made to flow down to the lower part of the reactor core 3, and the pressure in that part is increased. Therefore, reactor water 4 flows upward from below the reactor core 3 and is heated by a nuclear reaction to generate high-temperature, high-pressure steam in the upper part of the reactor pressure vessel 1 . This steam is then led out through a main steam pipe (not shown) and is configured to be supplied to a generator-driven turbine (not shown).

Further, inside the reactor containment vessel 2, a plurality (two tanks in the figure) of condensing tanks 5 and 7A and 7B are arranged at a position higher than the water level of the reactor water 4. These condensation tanks are connected to the gas phase IA in the reactor pressure vessel 1 through piping 8A.

8Bf, and has the function of keeping the pressure inside the reactor pressure vessel 1 constant.

On the other hand, a plurality of sets (two sets in the figure) of pressure detectors 91.9B are arranged outside the reactor containment vessel 2. 9B is connected to each detector 9, and the instrumentation piping 10 is connected to the condensation tanks 7A and 7B.
10B, each condensing tank 7A,
7B'i, the pressure in the gas phase IA of the reactor pressure vessel 1 is detected, and pressure signals Pa and Pbk are output.

In addition, there are multiple sets (two sets in the figure) outside the reactor containment vessel 2.
11B is arranged in the water level detector 11 of. Each of the water level detectors 11A and 11B is a pair of differential pressure detectors IJ.
A-,, IJA-, and 11B-1, JIB, and arithmetic units 11A- and IIB-.

It is made up of gold and gold. And differential pressure detector IJA
The pressure in the gas phase 6-JA is applied to the branch pipes 12 branched by the instrumentation pipe 10 through 'ff, and the pressure in the gas phase 6-JA is applied to one of the differential pressure detectors 11 at -s. The liquid phase IB is supplied to the side piping 13 through -,
The pressure at the high position of the other differential pressure detector 1 is applied.
The pressure at a low position within the liquid phase IB is applied to 1 and -m via an instrumentation pipe 138-2. Therefore, the computing unit 11 calculates the reactor water level in the reactor pressure vessel 1 based on the differential pressure detected by the differential pressure detectors JJA-, , 11-1, and outputs water level signals L&W. is configured to output. Similarly, the differential pressure detector JIB-1゜11B
The pressure in the gas phase IA is applied to the differential pressure detector JIB-1 through the branch pipe 12Bf branched from the instrumentation pipe 10B, respectively, and the pressure in the gas phase IA is applied to the instrumentation pipe 13B-1 to the differential pressure detector JIB-1.
The pressure at a high position in the liquid phase IB is applied through f, and the pressure at a low position in the liquid phase IB is applied to the other differential pressure detector JIB-, through the instrumentation pipe 13B-2. Therefore, in the computing unit 11B-1, both differential pressure detectors 11B-
, , IIB-, is configured to calculate the reactor water level in the reactor pressure vessel 1 based on the constant differential pressure detected by the reactor pressure vessel 1 and output the full water level signal Lb.

Moreover, a plurality of sets (Fi 2 sets in the figure) of temperature detectors 14A and 14B are arranged outside the reactor containment vessel 2. These are provided at various locations inside the containment vessel 2, and the detection unit 74
A-1, 14k-2, 141-2゜141-4 and 1
4B-1+ 14B-2+ 14B-3+14B-4
Input all detection signals from and generate temperature signals Ta, Tb f
configured to output.

Each recirculation pump 6 has a 6B suction pipe 6iA1゜6B.
The flow rate in -1 is detected by a flow rate detector 15A.

15B and each flow rate detector 15A.

Flow rate signals Fa*Fb are output from 15B.

Figure 2 shows the circuit configuration of the reactor water level detection device.
In the figure, 161.16B is a correction circuit. Each correction circuit 16
It is composed of 16BIi pressure correction circuits J7A, 27B, @ degree correction circuit 18, 18B, and dynamic pressure correction circuit 191.19B.

17B is connected to the pressure correction circuit 17, and 17B is connected to the water level detector 11.
The water level signals La and Lb from 11B are input manually, and the pressure signal Par from 9B is sent to the pressure detector 9.
Pb is input, and correction for changes in water level pressure as shown in FIG. 3 is performed. That is, since the input water level signals La and Lb change according to the pressure inside the reactor pressure vessel 1, the pressure detection signals Pa from the pressure detectors 9A and 9B.

Based on pb, the input water level signals La, Lbf can be pressure corrected as shown in the virtual line.

The density correction circuit 181.18B also sends a temperature signal Ta from 14B to each temperature detector 14.

Tbi is input to perform correction for changes in water level density as shown in FIG. In other words, the human water level signal La r Lb changes depending on the density, but since the density changes depending on the temperature conditions inside the reactor containment vessel 2, the temperature signal Ta from 14B is sent to the temperature detector 14.
, Tb, the input water level signals La, Lbf can be density-corrected as shown in the virtual line.

In addition, the dynamic pressure correction circuit 191.19B sends flow rate signals Fa, Fbf from 15B to each flow rate detector 9-hanger 15.
The data is input and corrections are made for changes in the dynamic pressure of the water level as shown in FIG. In other words, the input water level signal La
, Lb changes depending on the dynamic pressure in the liquid phase IB (flow rate in the core 3), but since the dynamic pressure changes depending on the flow rate in the recirculation system, the flow rate for detecting the flow rate in the recirculation system is Detector 15A.

Based on the flow rate signal Fa + Fb from 15B, the manual water level signal can be corrected for dynamic pressure as shown in the virtual line.

Therefore, in each correction circuit 16, 16B is a pressure correction circuit 171.17B for water level signals La, Lb and K input manually from IIB to the water level detector 11.

In the density correction circuit 18, 18B and the dynamic pressure correction circuit 19,
19B, and the corrected water level signal L
It is configured to send A, LB to the water level indicator of the reactor control device, the reactor emergency shutdown system, etc., as well as to an engineering safety facility.

Output cable of both correction circuits 16A and 16B -10 = dynamic pressure correction circuit JJ? The corrected water level signals LA and LB output from A and 29B are compared with each other in a comparator 20. This comparator 20 receives both corrected water level signals LA and LB.
If there is a difference between the two, an abnormality detection signal is output to the Elk alarm 21.

Moreover, the pressure signal Pa from each pressure detector 91.9B
*Pb is output to another comparator 22.

When there is a difference between the detection values of the pressure measuring force detectors 9A and 9B, the comparator 22 outputs the abnormality detection signal E3 to the alarm 21, and the alarm 21 outputs the abnormality detection signal E, E1.
When at least one of these is input, an alarm operation (generating an alarm sound, lighting an alarm lamp, etc.) is performed.

Next, the functions and effects of this embodiment will be explained.

First, each water level detector 11 detects the water level of the reactor water 4 in IIB based on the differential pressure inside the reactor pressure vessel 1.
The detection results include errors due to changes in the process conditions of the reactor water 4, such as the pressure inside the reactor pressure vessel 1, the density of the reactor water 4, and the flow rate of reactor water flowing through the reactor core 3. it is conceivable that.

Therefore, the amount of change in process conditions is detected by two process condition detection systems, and the water level detector 11 is
Correct the detection result of B.

One of the process condition detection systems is composed of a pressure detector 9A, a temperature detector 14A, and a flow rate detector 15A, and the other one is composed of a pressure detector 9B, a temperature detector 14B, and a flow rate detector 15B. Ru.

Therefore, the water level signal La from one water level detector 11k is
As shown in FIG. 2, the pressure is corrected in the pressure correction circuit 11A based on the pressure signal input from the pressure detector 9A, and then the pressure is corrected in the density correction circuit 18 based on the pressure signal input from the temperature sensor 14A. The density is corrected based on the manually input temperature signal, and finally the dynamic pressure is corrected in the dynamic pressure correction circuit 19A based on the flow rate signal Fa input from the flow rate detector 15A, and then output as a corrected water level signal LA to the reactor control device. .

Further, the water level signal Lb from the other water level detector 11B is also input to the correction circuit 16B as shown in FIG.
Correction is performed sequentially through the 7B1 density correction circuit 18B and dynamic pressure correction circuit 19Bf, and outputted to the reactor control device as a correction water level signal LB.

Therefore, errors in detecting the reactor water level due to changes in reactor water process conditions are eliminated, and highly accurate detection of the reactor water level is achieved.

Further, two correction water level signals LA are supplied to two systems of correction circuits 16 through 168 under the same conditions.

LB is obtained, but if there is a leak from the piping in the process condition detection system of either system, and a difference occurs between the two corrected water level signals LA and LB, the two pressure signals Pa * Pb There will also be a difference.

However, in such a case, at least one comparator 2
The abnormality detection signal El or E2 is output from 0 or 22 to the alarm 21, and the alarm 21 activates the alarm, so that the operator can immediately know that an abnormality has occurred, and take appropriate action ffi'(i- Therefore, safety and reliability can be improved.

〔Effect of the invention〕

As detailed above, the reactor water level detection device according to the present invention includes a plurality of sets of water level detectors that detect the reactor water level based on the differential pressure within the reactor pressure vessel, and a water level detector for each set of water level detectors. A plurality of process condition detection systems are installed correspondingly to detect changes in the process conditions of the reactor water, and the detection results obtained from each of the water level detectors are used to detect changes in the reactor water based on the outputs of the process condition detection systems. Multiple correction circuits that correct according to process conditions, a comparator that compares the outputs of these correction circuits and outputs an abnormality detection signal if there is a difference in these outputs, and an abnormality detection signal from this comparator. It is equipped with an alarm device that is operated manually.

Therefore, according to this reactor water level detection device, detection errors caused by changes in the reactor water level conditions can be removed by correction according to changes in process conditions, and the reactor water level can be detected with high precision. can be performed and multiple detection tEfi
By comparing the values, the detection system can be fully monitored, and the safety and reliability of nuclear reactor operation can be improved.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, and FIGS. 1 and 2 are schematic configuration diagrams of a reactor water level detection device, and FIGS.
The figure is a diagram showing the correction function of the correction circuit. ! ...Reactor pressure vessel, 3...Reactor core, 4...Reactor water, 9, 9B...Pressure detector, 11, 11B...
Water level detector, 14, 14B...Temperature detector, 15A
. 15B...Flow rate detector, 16, 16B...Correction circuit, 20, 20f3...Comparator, 21...Alarm. Applicant's agent Patent attorney Takehiko Suzue 15-

Claims (4)

[Claims] (1) Multiple sets of water level detectors that detect the reactor water level based on the differential pressure in the reactor pressure vessel, and a corresponding one for each water level detector to detect changes in the process conditions of the reactor water. a plurality of process condition detection systems; a plurality of correction circuits that correct the detection results obtained from each of the water level detectors according to changes in the process conditions of the reactor water based on the output of each of the process condition detection systems; A comparator that compares the outputs of the correction circuits and outputs an abnormality detection signal if there is a difference between these outputs, and an alarm that operates an alarm by inputting the abnormality detection signal from this comparator. 'f, Characteristic nuclear reactor water level detection device. (2) Each process condition detection system includes a pressure detector that detects the pressure in the gas phase of the reactor pressure vessel, a temperature detector that detects the temperature in the reactor containment vessel, and a reactor water flow rate in the reactor core. A nuclear reactor water level detection device according to claim 1, comprising a flow rate detector for detecting a flow rate. (3) Each of the correction circuits includes a pressure correction circuit that corrects the pressure of the detection result of the water level detector based on the detection value of the pressure detector, and a pressure correction circuit that corrects the detection result of the water level detector based on the detection value of the temperature sensor. Claim (2) comprising a density correction circuit for correcting the density and a dynamic pressure correction circuit for correcting the dynamic pressure of the detection result of the water level detector based on the detection result of the flow rate sensor. The reactor water level detection device described. (4) The reactor water level detection device according to claim (1), wherein the alarm operates an alarm even when there is a difference in the detection speed of the plurality of pressure detectors.