JPH0351800A - Filter device for high concentration aerosol - Google Patents

Abstract

PURPOSE:To suppress a degradation of a filter and to improve a reliability of a containment venting during an accident by preventing a clogging by a capture of high concentration aerosol particles. CONSTITUTION:During a nuclear reactor accident, an aerosol containing steam and radioactive substances is generated in a nuclear reactor containment vessel 1, and subsequently a pressure in the containment vessel rises. The steam and the aerosol are discharged to a suppression pool from vent pipes 4. The steam is condensed by suppression pool water and a part of the aerosol is transferred into the water by a scrubbing effect. Moreover, when the pressure rises further, the containment vessel is to be opened to an atmosphere through a filter 7 by opening a isolation valve 6. In this case, a fluid is introduced to the filter passing through a hole farther from an inlet. At that place, the steam is condensed and the aerosol is captured by a fibered filter material. Even if clogging occurs in midway, the filter is not degraded because the fluid is introduced through a hole closer to the inlet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to nuclear reactors, and more particularly to an apparatus for minimizing the amount of steam and aerosol containing radioactive materials released into the environment in the event of an accident.

[Conventional technology]

A French filter vent system is shown in Figure 5. The conventional technology is EUROPE AFTERC1 (ERNO
BYLPARTI MEASIJRES To MIT
As described in LGATE 5EVERE ACCIDENT, in order to prevent damage to the containment vessel due to an increase in the internal pressure of the containment vessel in the event of an accident, venting was performed via a filter vent system, and aerosols were removed by a filter before being released into the environment.

However, the equipment is large in size to prevent clogging due to aerosols containing highly concentrated radioactive materials released from the containment vessel in the event of an accident.

[Problem to be solved by the invention]

The above conventional technology has a problem in that it does not take into account clogging caused by collection of high concentration aerosol particles.

An object of the present invention is to suppress deterioration in filter performance due to clogging in a filter device.

[Means to solve the problem]

The above object is achieved by providing a filter structure with a large number of small diameter holes or by providing a multilayer filter structure.

[Effect]

By introducing fluid through a large number of small-diameter holes, it is possible to suppress a decrease in filter performance due to clogging. It is explained as follows. That is, since the fluid is introduced into the filter section from a location farthest from the initial inlet, clogging occurs sequentially from the location farthest from the inlet. Even if clogging occurs, the performance of the filter will not deteriorate because of the large number of pores.

When the filter has a multilayer structure, suppression of filter performance deterioration can be explained as follows.

That is, when the filling in the -th stage becomes clogged and the pressure increases, the partition plate opens. Therefore, the fluid is introduced into the second stage filter. By performing this sequentially, it is possible to suppress a decrease in the performance of the filter.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
In the figure, 1 is a reactor containment vessel, 2 is a reactor pressure vessel, 3 is a reactor core, 4 is a vent pipe, 5 is a suppression pool, 6 is an isolation valve, 7 is a filter, and 8 is an emergency core cooling system.

At the time of a nuclear reactor accident, aerosol containing steam and radioactive materials is generated in the reactor containment vessel 1. Therefore, the pressure inside the containment vessel increases. Steam and aerosol are discharged from the vent pipe 4 into the suppression pool. The steam is condensed by the suppression pool water, and a portion of the aerosol is transferred into the water due to the scrubbing effect. Furthermore, when the pressure rises, the isolation valve 6 is opened and the air is released to the atmosphere via the filter 7.

FIG. 2 shows an example of a filter structure. Fluid is introduced into the filter through holes remote from the inlet. Therefore, the fibrous fill material performs vapor condensation and aerosol collection. Even if the holes become clogged on the way, fluid will be introduced through the holes near the inlet.

Therefore, the filter performance does not deteriorate due to clogging.

The filter material should preferably be one that does not corrode, such as glass fiber, from the viewpoint of use under high temperature and high pressure, and from the viewpoint of maintenance.

An example of another filter structure is shown in FIG. 3, where the filter has a multi-layer structure, with each layer separated by a Lavoucha disk. −
When the fill in the tiers becomes clogged and the pressure increases,
The Lovecha disk breaks and the second stage filter works.
In this way, the performance of the filter is not degraded.

FIG. 4 shows an example in which a spring-loaded partition plate is used instead of the Labuture disk. In this case, too, when the pressure increases due to clogging, the partition plate opens.

In this way, even if clogging occurs, the filter performance will not be degraded.

In addition, this high concentration aerosol filter device.

It can be used with high reliability even in cases such as dry well venting.

〔Effect of the invention〕

According to the present invention, even if clogging occurs, the filter performance does not deteriorate, so that the containment vessel can be vented with high reliability in the event of an accident, and the release of radioactivity to the environment can be kept to a minimum. can.

[Brief explanation of drawings]

Figure 1 is a system diagram showing one embodiment of the present invention, Figures 2 and 3 are
4 is an explanatory diagram of an embodiment of the filter structure, and FIG. 5 is a system diagram of a French filter vent system. 1... Reactor containment vessel, 2... Reactor pressure vessel, 3
...Reactor core, 4...Vent pipe, 5...Suppression pool, 037 03G Figure 1 Figure Figure Figure Figure

Claims (1)

[Scope of Claims] 1. A filter device for high concentration aerosol, characterized in that it collects high concentration aerosol particles in a nuclear reactor. 2. The filter device for high concentration aerosol according to claim 1, characterized in that pressure loss due to clogging is prevented. 3. A filter device for high concentration aerosol, which is characterized by introducing fluid through a large number of small-diameter holes and collecting aerosol and vapor using a fibrous filter material. 4. A filter device for high-concentration aerosol, characterized in that the filter has a multilayer structure, and there is a partition plate between each layer that opens when the pressure increases.