JPS6244638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a primary reactor containment vessel sump flow rate measuring device that improves the method of draining water from a reactor primary containment vessel sump to a reactor building sump.

Conventional reactor primary containment vessel (hereinafter referred to as D/W)
The water generated in the reactor is collected in the D/W sump (reactor primary containment vessel sump) in the D/W, and from there is transferred to the R/B sump (reactor building sump) in the reactor building (hereinafter referred to as R/B). A flow rate converter (hereinafter referred to as FT) is inserted into the drainage line to detect the flow rate, and an alarm is generated when the flow rate exceeds a set value. A switch was installed to issue an alarm if water accumulated above a set value. However, in such devices, since the flow rate flowing through the drainage line is very small, there is a high possibility that the siphon will break, and since the FT is a turbine meter, there is a high possibility that it will malfunction due to dirt, rust, etc. It lacked sex.

In view of the above circumstances, the present invention provides a primary reactor containment vessel sump flow rate measuring device that can accurately measure low flow rates and continues stable operation.

The figure will be explained in detail below.

Reactor primary containment vessel sump (D/W sump) 1
The water generated in D/W13 is collected and sent to the reactor building sump (R/B sump) by drainage line 2.
11 by the siphon principle. The D/W sump opening of the drainage line 2 is connected to an inverted U-shaped pipe 3 provided in the D/W sump 1, and there is a U-shaped seal part 4, a control valve 5 that controls discharge, and a flow rate detector (hereinafter referred to as
Insert 6 (called FI).

The D/W sump 1 is equipped with two high and low water level detection switches (hereinafter referred to as LSH and LSL) 8 and 7.
The water level in the D/W sump 1 is detected and the control valve 5 is activated.
control. Open the control valve 5 with the signal from LSH8,
The control valve 5 is closed by the signal from LSL7. LSL7 is above the opening end 3a of the above-mentioned inverted U-shaped tube 3 (50m/m ~
100m/m), and LSH8 is installed at an appropriate position above it. A high/high water level detection switch (hereinafter referred to as LSHH) 9 is further installed above the LSH 8. LSHH9 uses the detection signal to activate alarm 15.
operate.

LSL7 and LSH8 separately guide their detection signals to control timers 10, 10 and alarm 16.

Further, a water level detection switch (hereinafter referred to as LS) 12 is set on the upstream side of the U-shaped seal portion 4, and the control valve 5 is closed by its detection signal. This U
A supply waterway 14 is connected upstream of the seal portion 4 and is controlled by a normally closed control valve 14a.

Note that the reference numeral 17 is an isolation valve in the event of an abnormality,
When there is an abnormality in the drainage line 2, the water is discharged to another system.

The structure is constructed as described above, and the operation is as follows.
The water level collected in D/W sump 1 is LSH
When the detection signal exceeds 8, the control valve 5 is opened by the detection signal, and water is discharged from the drainage system 2 to the R/B sump 3. water level goes down
When LSL7 operates, control valve 5 is closed. That is, D/
Intermittent drainage is performed in which a certain amount of water is stored in the W sump 1 and then the certain amount is drained. LSL7 is inverted U-shaped tube opening 3
It is located above a and prevents air from entering the drainage system 2. LSH8 is set at an appropriate position, but if an abnormality occurs and the water level exceeds LSH8 and reaches LSHH9, an alarm will be issued.

Water dropped into drainage system 2 is detected by FI6. If the flow rate is large, it will issue an alarm signal. This FI6 does not have the problem of the propeller rusting and becoming inoperable like the conventional FT. There is no clogging because the pipe diameter of the drainage system 2 (approximately 2 inches) is used.

Also, timers 10 and 10 are activated by LSL7 and LSH8 signals.
and record the operating time. By this, when D/W sump 1 is full of water, the drainage time is detected,
Alerts you if there is an abnormality. Along with the flow rate detection by FI6, it is possible to grasp the overall situation, such as the tendency of increase in flow rate depending on the drainage interval.

When the drainage water runs out in U-shaped seal part 4, LS
12 detects this and closes the control valve 5. Then, the control valve 14a is opened to supply water from the supply waterway 14, and the siphon function of the drainage system 2 is maintained.

As described above, the primary reactor containment vessel sump flow rate measuring device of the present invention can accurately detect the drainage flow rate by once storing a small amount of flowing water in the sump and discharging it in fixed amounts at a time. Also, understand the drainage interval,
The flow rate can be checked by conversion. Furthermore, by measuring this interval, it is possible to measure the tendency of increase or decrease in the amount of water leaking into the D/W. This is a unique device that maintains the siphon principle without introducing air into the drainage system and can accurately measure low flow rates.

[Brief explanation of the drawing]

The figure is a configuration diagram showing one embodiment of the present invention. 1...D/W sump (reactor primary containment vessel sump, 2...drainage system, 3...inverted U-shaped pipe, 4...U-shaped seal section, 5...control valve, 6...FI (flow rate detection) 7, 8, 9...LSL, LSH, LSHH (water level detection switch low, high, high/high), 10...timer,
11...R/B sump reactor building sump), 12
...LS (water level detection switch), 13...D/W,
14... Supply waterway, 15, 16... Alarm.

Claims (1)

[Claims] 1. A drainage system based on the siphon principle is connected from the primary reactor containment vessel sump to the reactor building sump, a control valve is inserted in the drainage system, and a high water level detection switch is connected to the reactor primary containment vessel sump. A reactor primary containment vessel characterized in that a low water level detection switch is installed, the control valve is controlled to open in response to a high water level detection signal, and to be closed in response to a water level detection signal from the low water level detection switch. Sump flow rate measuring device. 2. The reactor primary containment vessel sump flow rate measuring device according to claim 1, characterized in that a flow rate detector is inserted into the drainage system to detect the drainage flow rate. 3. A patent characterized in that an inverted U-shaped tube is inserted into the reactor primary containment vessel sump and one end thereof is connected to the drainage system, and a low water level detection switch is set above the open end of the inverted U-shaped tube. A reactor primary containment vessel sump flow rate measuring device according to claim 1. 4. Claim 1, characterized in that the reactor primary containment vessel sump has a high/high water level detection switch located higher than the high/high water level detection switch, and the alarm is controlled by this high/high water level detection switch.
Reactor primary containment vessel sump flow rate measuring device as described in . 5. A patent claim characterized in that one or more timers controlled by high water level and low water level detection switches are provided to measure when the reactor primary containment vessel sump is full of water, drain time, etc. A reactor primary containment vessel sump flow rate measuring device according to scope 1. 6. The atom according to claim 1, characterized in that a U-shaped pipe passage is configured in the drainage system, and a water level detection switch is provided on the upstream side of the drainage system, and the control valve is closed when a drop in the water level is detected. Primary containment vessel sump flow rate measuring device.