JPS59104584A - Sampling device of radioactive fluid - Google Patents

Abstract

PURPOSE:To eliminate danger of exposure even in case of accident by connecting a measuring pipe, a liquid introducing pipe and a gas introducing pipe through a valve and connecting the entrance end with a pure water supply pipe and a diluted gas supply pipe, and connecting the exit end with a diluted liquid container. CONSTITUTION:Sampling is started after completion of cleaning of the system before sampling. A liquid sample containing a dissolved gas such as hydrogen, etc. is collected in a sample measuring pipe 105. Then, the dissolved gas contained in the liquid sample water in the sample measuring pipe 105 is diffused into a diluting device 106. The dissolved gas diffused in the diluting device 106 is moved to a gas container 109. By a series of processes, the dissolved gas sample is stored in the gas container, the liquid sample is stored in a diluted liquid container 108, and the gas sample is stored in the diluting device in a diluted state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radioactive fluid sampling device.

In light water reactor type nuclear power plants, a secondary coolant loss accident (this accident is a design accident and almost never occurs in reality) occurs when the fuel cladding tube (zirconium tube) and the secondary coolant, water. Hydrogen may be generated by the reaction. This hydrogen is dissolved in the secondary coolant and exists as a dissolved gas,
The value is 25 to 35 N, which is the normal value for pressurized water reactors.
cc/Kg - 2000 N cc/K for H2O
y-H2O may also be reached. Furthermore, if fuel damage occurs, the concentration of radionuclides in the secondary coolant may be an order of magnitude higher than normal values. Furthermore, in the event of a rupture accident in the coolant pipe, there is a possibility that radioactive gas (1311, 133) (e, 85Kr) in the second coolant will be released into the gas phase within the containment vessel. In order to accurately understand the situation in the event of such an accident, it is essential to sample and analyze the secondary coolant or the gas in the containment vessel.

In addition, the accident at the Three Mile Island nuclear power plant started 1-1.
In order to grasp the extent of core damage in the event of a similar accident or secondary coolant loss accident, it has become mandatory to install a printer device.

Next, a conventional sample collection device that collects primary coolant (light water, or H2O) as a sample during normal operation will be explained with reference to Figure 1. (1) is a sample cooler, (2) is a pressure reducer, (
3) is the sample collection pipe, (4) is the sink, Ql is the attachment/detachment part, aυ is the sample inlet pipe, (+21 (13) is the sample outlet pipe, (11 is the drain pipe, (15) fll is the descendant conduit,
al) to ■ are on-off valves, which lead the sample water from the sample inlet pipe 01) to the sample cooler (1) through the valve Qυ.
After being cooled down to room temperature, it is led to a pressure reducer (2).
Here, the pressure is reduced to around normal pressure. Also, use sample water as a valve)
When collecting samples from the sample outlet area via the @conduit, close the valve conduit (C) and open the valve @2 to allow sufficient water to flow through, then open the valve conduit and allow water to flow for a while. 4'P (2) is opened for a quick review. After receiving the sample water from the sample outlet pipe Q3) in the sink (4), drain it to the appropriate treatment equipment through the drain pipe oo, and then drain the sample water from the sample outlet Pipe (1
3) Collect an appropriate amount of sample water from step 3. In addition, when taking a sample using the sample collection tube (3), close valve @4 and close valve ＠4. After opening JcI4 (branch) (4) and allowing the sample water to flow sufficiently into the sample collection tube (3), close the valve holder QA @ (E) and insert the sample water into the sample collection tube (3).
) from the desorption part (11).In addition, when measuring the concentration of dissolved gas in the secondary coolant, collect a liquid sample containing dissolved gas using the sample collection tube (3) in the same way as above, and After separation, the gas was degassed manually, and the gas phase was measured using an analyzer (J''C, the concentration of dissolved gas (H2). In addition, when collecting gas samples, the same method as above was used. After collecting a gas sample using a sampling tube (3), the gas sample was separated using a micro cylinder.

At nuclear power plants, during normal operation, the radioactivity concentration per unit volume of the fluid to be sampled, such as secondary cooling water, is low, so even if the sample sampling device shown in Figure 1 is used, there is not much risk of exposure. There was a problem in that when the radioactivity concentration was high at the time of an accident, there was a large risk of radiation exposure for workers themselves during their work.

The present invention has been made to solve the above-mentioned problems, and includes a metering tube, a liquid introduction tube and a gas introduction tube connected to the inlet end of the metering tube via an on-off valve, and a gas inlet tube connected to the inlet end of the metering tube. A pure water supply pipe and a diluent gas supply pipe are connected to each other via an on-off valve, a diluted liquid receiver is connected to the outlet end of the meter-1 pipe through an on-off valve, and another is connected to the outlet end of the metering pipe. A diluter connected via an on-off valve, a vacuum pump and a dilution gas receiver connected to the diluter, and a dilution gas branch supply branched from the dilution gas supply pipe and connected to the diluter via an on-off valve. This is a radioactive fluid sampling device characterized by a pipe, and its purpose is to collect the radioactive fluid to be sampled without the risk of being contaminated, even when measuring the radioactivity concentration in the event of an accident. can. Collection time can be shortened. The present invention also provides a radioactive fluid sample collection device that can perform repeated analyzes in parallel.

Next, the radioactive fluid sample collection device of the present invention will be explained with reference to an embodiment shown in FIG.
155) is an on-off valve, (161) to (166) are measuring instruments, and (V) is India. Specifically, each of the above elements is as follows. That is, (101-a) (101-b)
k'LKIRN, -(102) is the pressure reducer, (1
04) is the sink, (ios) is the sample measuring tube, (
106) is a diluter, (107) is a diluted pure water meter, (1
08) is the diluent receiver, (109) is the gas receiver, (1
10) is a vacuum pump, (111) is a sample system (specifically, a primary coolant, a residual heat removal system for containment vessel atmospheric gas, etc.), and here, (111-21) is a liquid system, (ul
-b) is a gas system. In addition, (112) is waste liquid and waste gas, (114) is the pure water line, (115) (118
) (119) is the vent line, (120) is the line to the liquid analyzer, (117) is the nitrogen gas line, (1
17-a) is the nitrogen gas branch line, (121) is the gas sample line to the analyzer, (122) is the diffused dissolved gas line to the analyzer, (161) is the sample pressure gauge, (
162) is a sample thermometer, (163) is a diluter pressure gauge, (164) is a diluter water level gauge, (165) is a diluent receiver water level gauge, and (166) is a gas receiver pressure gauge.

Next, the operation of the radioactive fluid sampling device will be explained.

Valves unless otherwise specified are assumed to be closed. (1)
To clean the diluter (106), use the valves (137) (139)
(134) (135) Open (144) and introduce pure water into the diluter (106). Then the valve (140)
t, xs3) (135) (136) (142) to drain the cleaning water. Repeat this operation to ensure completeness. (II) Cleaning of the diluent receiver (108) is performed using valves (137) (139) (134) (1
36) Open (148) (155) and introduce pure water into the diluent receiver (108).

Then, open the valves (145) and (141) to discharge the purified water. For completeness, this operation should be replaced with (
repeat Further, this cleaning operation may be performed after the step of leaping, which will be explained later. (III) The diluter (106) and gas receptor (109) are cleaned and evacuated using the valve (151) (1
53) Open (152), operate the vacuum pump (110), and evacuate the diluter (106) and gas receptor (109) while monitoring the pressure gauges (166) and (163). Next, (140), (151), and (153) are opened to supply nitrogen gas, and the diluter (106) and gas receptor (
109) Fill the inside with nitrogen gas. After repeating the above operation to replace the inside of the diluter (106) and gas receptor (109) with nitrogen gas several times, the valves (151) and (153) are replaced with nitrogen gas.
(152) is opened again and the vacuum pump (110) is started to evacuate the inside of the diluter (106) and gas receptor (109) while monitoring the pressure gauges (166) and (163).

This completes the cleaning of the system before sample collection, and then begins sample collection. (Separation and dilution of M dissolved gas are performed using a valve (131-
a) C132-a) (133) (136) (14
3) Open the system and flow a liquid sample containing dissolved gas such as hydrogen into this system to replace this system with sample water. All valves are then closed, which causes valve (133) (
A predetermined amount of sample water is collected into the sample measuring tube QO5) sandwiched between 134), 135, and 136). Valve (135) is then opened and 81 sample tubes (105
) diluter C106 to remove the dissolved gas contained in the liquid sample water in
) dissipates into the inside.

To be sure, the valve C138) (134) may be opened and the dissolved gas contained in the sample water in the sample measuring tube (105) may be pushed out to the diluter (106) while stirring with nitrogen gas. . Then the valve (151) C153)
is opened to allow the dissolved gas dissipated in the diluter (106) to move to the gas receiver (109). At this time, the pressure is measured using pressure gauges (166) and (163). Thus, the gas dissolved in the sample water is stored in the gas receptor (109) after being dissipated. (g) Following the step of 1PJ) above, the liquid sample is diluted. The dilution of the liquid sample mentioned here refers to the liquid sample collected in step M (in the lower part of the diluter (10G)). Water valve (1
37) (139) (134) (135) (144
) is opened and introduced into the diluter (106). The above pure water measurement may be performed while watching the water level gauge (164). Also valve (138) (134)
(135) (1) may be opened to mix nitrogen gas and the diluted sample in the diluter (106).

Then valves (135) (136) (1,18) (1
55) and open the valves (140) and (153).
The diluted sample in the diluter (106) is transferred to the diluted liquid receiver (108) using nitrogen gas.

Thus, the diluted sample is in the diluent receiver (108).
Water can be stored. (■ Sampling and dilution of the gas sample are performed following the step (V) above. Valve (153) (15
2) is opened, the vacuum pump (110) is started, and the inside of the diluter (106) is evacuated while monitoring the pressure gauge (163).

Then valves (131-b) (132-b) (133)
(136) (143) open, gas sample (111-
b) into the system to replace it. After a predetermined time has elapsed,
When all valves are closed, a volume of gas sample is taken in the metering tube C105). Next, after opening the valve (135), (138) and (134) are opened to introduce nitrogen gas and dilute the gas sample while monitoring the pressure 81 (163) of the diluter (106).

The degree of dilution can be determined by measuring the pressure of the sample water (pressure gauge (161)
Detected value, volume of diluter (106), sample measuring tube (
It is determined by the volume of the diluter (105) and the pressure (detected value of the pressure gauge (163)) of the diluter (10(3)), and can be easily calculated.

Thus, diluted gas is stored in the diluter (106). As described above, through the series of steps (1) to (■), the dissolved gas sample is placed in the gas receptor C109, the liquid sample is placed in the diluent liquid receptor (108), and the gas sample is placed in the diluter (106). Each is stored in a diluted state.

Therefore, each concentration can be measured by introducing them into the analyzer through lines (122), (121), and (120).

Further, the series of steps from (11 to (V)) can be automatically and remotely controlled by a control device such as a program sequencer or a microcomputer.

The radioactive fluid sample collection device of the present invention is configured as described above, and (1) radioactive fluid to be collected can be collected without risk of exposure even when radioactivity concentration is high during an accident.

(n) Collection time can be shortened. That is, the above (1)
~(Sampling time will be longer for combinations other than the VD process.

For example, as shown in the following table, if the required sampling time according to the present invention is 100, it will be 100 or more for combinations other than the present invention.

This is because, in the case of the present invention, the same sample can be separated into a dissolved gas and its residual liquid, and the dissolved gas can be used as a gas sample and the residual liquid can be used as a liquid sample.

(Translation)Able to repeat analysis. That is, in the present invention, since the diluted liquid sample and gas sample can be stored in separate containers, the analysis can be repeated.

(iv) Analyzes can be performed in parallel. That is, in the present invention, since the sample to be analyzed can be stored in a diluted state in a separate container, analysis can be performed simultaneously and in parallel.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a conventional radioactive fluid sampling device, and FIG. 2 is a system diagram showing an embodiment of the radioactive fluid sampling device according to the present invention. (105)...Measuring tube, (1O6)...
... Diluter, (108) ... Dilution liquid receptor, (109) ... Dilution gas receptor. (110)...Vacuum pump, (111-a)・
...Liquid introduction pipe, C11l-b)...Gas introduction pipe, (114)...Pure water supply pipe,
(117)...Dilution gas common supply pipe. (117-a)... Dilution gas branch supply pipe,
C133)...... On-off valve on the inlet end side of 105) in the metering tube, (134)...... Metering tube (10)
5) Other on-off valves on the inlet end side, (135)...
...Another on-off valve on the outlet end side of the metering pipe (105'). (136)...Outlet end fl of metering tube (105)
ll open/close valve. (140)... Diluent gas branch supply pipe (ii7-
a) On-off valve. Continued from page 1 0 Inventor Hitoshi Miyamoto 0 2-1-1 Niihama, Arai-cho, Takasago-shi Mitsubishi Heavy Industries, Ltd. Takasago Laboratory 0 Inventor Toshio Funakoshi 2-1-1 Niihama, Arai-cho, Takasago-shi Mitsubishi Heavy Industries, Ltd. Takasago Research Institute ■Applicant: Kansai Electric Power Co., Inc. 3-3-22 Nakanoshima, Kita-ku, Osaka ■Applicant: Shikoku Electric Power Co., Inc. 2-5 Marunouchi, Takamatsu City ■Applicant: Kyushu Electric Power Co., Ltd. Watanabe, Chuo-ku, Fukuoka City 2-1-82 Dori ■Applicant Japan Atomic Power Co., Ltd. 1-6-1 Otemachi, Chiyoda-ku, Tokyo Applicant Mitsubishi Heavy Industries, Ltd. 2-5-1 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] A measuring pipe, a liquid introduction pipe and a gas introduction pipe connected to the inlet end of the measuring pipe via an on-off valve, and a pure water supply pipe and diluent gas connected to the inlet end of the measuring pipe via another on-off valve. A supply pipe, a diluent receiver connected to the outlet end of the measuring pipe via an on-off valve, a diluter connected to the outlet end of the measuring pipe via another on-off valve, and a diluent receiver connected to the outlet end of the measuring pipe via another on-off valve. A radioactive fluid sampling device comprising a vacuum pump, a dilution gas receiver, and a dilution gas branch supply pipe branched from the dilution gas supply pipe and connected to the diluter via an on-off valve.