JPS58168996A - Emergency gas processing 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 The present invention relates to an emergency gas treatment device, and more particularly, to an improvement of the emergency gas treatment device to prevent indoor gas from leaking directly to the outside of a nuclear reactor such as a BWFL plant. be.

The emergency gas processing equipment removes as much radioactive materials as possible, such as radioactive iodine, that leak into the reactor building in the event of an emergency such as a loss of reactor coolant accident, and releases it into the outside atmosphere. BW is designed to prevent the release of radioactive materials and keep the exposure dose in the 5 surrounding areas as low as possible.
It is installed in the R plant.

By the way, as shown in Figure 1, the conventional gas treatment equipment for seeding and regular use is divided into two parts: the reactor containment volume a2t that stores the reactor pressure vessel l - the reactor construction volume 3 that stores the 'JJ' ,
Emergency gas treatment MA11T consisting of a radioactive material removal filter train 5 for removing radioactive materials such as v5 electricity, butterfly ramie 4, radioactive covering trees, etc., and exhaust 7RN 6, etc.
In other words, the gas inside the reactor m3 is aerated in a fixed amount according to the exhaust capacity of the exhaust fan 6, and the inside of the reactor end 13 is made to have a negative pressure. The main focus is on
This prevents the 3 yen worth of gas from the reactor from being released directly to the outside. And reactor 41! ! The negative pressure inside the tank 3 was simply measured by a differential pressure generator 8 and indicated by a differential pressure indicator 9.

Therefore, when this device is actually operated during a leakage test of reactor building 3 in the existing BW R7' land, 1li1
Since the exhaust capacity of the exhaust fan 6 is usually designed to be large from the viewpoint of plant function maintenance, the inside of the nuclear reactor 3 has a negative pressure larger than necessary.

However, this would result in a large amount of gas being forcibly exhausted), which is not desirable from the perspective of reducing radiation exposure in the Kanbe area.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to maintain the negative pressure in the reactor building at the minimum level necessary to completely prevent the negative pressure from leaking directly to the outside, and to maintain the negative pressure in the surrounding area. An object of the present invention is to provide an emergency gas treatment device that can reduce radiation exposure.

The features of the present invention include a stage for measuring the negative pressure that suppresses the negative pressure t1 in the reactor building, and the output of this negative pressure 1 measuring means to prevent the negative pressure in the reactor building from directly leaking. The present invention is configured to include a control means for controlling at least one of the electric valve and the exhaust fan to adjust the exhaust air volume so as to achieve a minimum predetermined negative pressure.

This will be explained in detail using

Fig. 2 is a system diagram showing one embodiment of the emergency gas treatment system of the present invention. The same parts and parts as in Fig. 1 are designated by the same reference numerals. G!
The output of the i-device 8 is divided by the difference F1. It is led to the indicator 9 to indicate the full negative pressure, and it is also led to the differential pressure regulator 10, and the opening regulator 11'&'1till is controlled by the output of the differential pressure regulator IO.
Then, the opening FrL of the electric butterfly valve 4 is adjusted by the opening degree regulator 11 f jli to adjust the exhaust air volume, so that the negative pressure inside the reactor building 3 is reduced and the gas inside the reactor building 3 is directly discharged to the outside. A minimum predetermined negative pressure is required to prevent leakage, eg, -0.25 inches.

According to the embodiment shown in Section 2, by simply adding a simple one-measurement control device to the conventional equipment, the negative pressure inside the reactor building 3 can be
: The minimum negative pressure required to prevent direct leakage can be maintained at 1, reducing exhaust volume and reducing radiation exposure in the surrounding area.

FIG. 3 is a system diagram showing another embodiment of the present invention, in which the same parts as in the ts1 diagram and #12 diagram are indicated by the same reference numerals. In FIG. 3, the frequency converter 12 is operated by the output of the differential pressure regulator IO, and the rotation speed of the drive motor 13 of the exhaust fan 6 is controlled by the output of the frequency & converter 12, thereby adjusting the exhaust air volume. The negative pressure inside the reactor S-3 is set to the minimum predetermined negative pressure necessary to prevent the gas inside the reactor S from directly leaking to the outside. You can get the same effect.

Note that the minimum necessary negative pressure inside the reactor building 3 varies depending on the outside air conditions, the situation of the openings in the reactor building 3, etc., and cannot be determined unambiguously, but the above conditions are the deciding factor. If so, it can be implemented by determining the minimum necessary negative pressure in advance and setting this in the differential pressure regulator IO.

Ninth, the opening degree of the electric butterfly valve 3 and the rotation speed of the drive motor 13 of the exhaust 7-an 6 may be controlled to adjust the exhaust air volume so as to achieve the minimum required negative pressure. Needless to say.

As explained above, according to the present invention, the negative pressure inside the reactor S can be maintained at the minimum negative pressure necessary to prevent leakage of A to the outside, and the negative pressure in the surrounding area can be maintained. This has the effect of reducing radiation exposure.

[Brief explanation of the drawing]

Fig. 41 is a system diagram of a conventional emergency gas processing device, Fig. 2 is a system diagram showing one embodiment of the emergency gas processing electric power production system of the present invention, and Fig. 3 is a system diagram showing another embodiment of the present invention. It is a diagram.

Claims (1)

[Claims] 1. Nuclear reactor II! In an emergency gas treatment device comprising an electric valve, a radioactive substance removal filter, an exhaust fan, etc. for preventing indoor gas from directly leaking to the outside, a voltmeter #j means for measuring negative pressure inside the reactor building; At least one of the motor-operated valve and the exhaust fan is configured so that the negative pressure in the reactor am reaches a predetermined negative pressure at the lowest limit necessary to prevent direct leakage to the outside by the output of the negative pressure measuring means. An emergency gas processing device characterized by comprising: a control means for controlling one side and adjusting an exhaust air volume.