JPH02306196A - Reactor container vessel - Google Patents

Abstract

PURPOSE:To achieve a suppression of a pressure rise inside a container vessel by providing a drywell with a steam generator to keep a temperature and a steam partial pressure at a drywell gaseous phase section higher enough than the temperature and the steam partial pressure of a suppression pool. CONSTITUTION:A radiation shielding wall 4 is provided in the perimeter of a reactor pressure vessel 3. A pedestal cavity 5 is formed by the inside of the pedestal 2 and a lower part of the vessel 3. A container vessel is so arranged to comprise a wet well 8 having a dry well 7 housing the vessel 3 and the shielding wall 4 and a toroidal type suppression pool 9 in such a manner that an atmosphere thereof will not diffuse outside. A vent pipe 10 is connected to the dry well 7 and the wet well 8 and the tip thereof 10 is opened under water of the pool 9. Then, a steam generator 11 is set at the bottom of the shielding wall 11 to keep a temperature and a steam partial pressure of a gaseous phase section of the dry well 7 higher enough than the temperature and the steam partial pressure of the pool 9.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to a reactor containment vessel, in particular, to suppress the pressure rise in the reactor containment vessel during an accident to a low level, and also to inactivate the reactor containment vessel. Regarding applicable nuclear reactor containment vessels.

(Prior Art) In general, a reactor containment vessel in a boiling water reactor is composed of a dry well in which a reactor pressure vessel containing a nuclear reactor is installed, and a wet well having a suppression pool. and the wet well are connected with a vent pipe, and the tip of the vent pipe is released into the suppression pool.

Incidentally, the gas phase portion within the reactor containment vessel is inertized with N2 gas in preparation for the generation of slag that is expected to occur in the event of an accident. Furthermore, when the pressure in the dry well rises due to water vapor or H2 gas generation during an accident, the generated water vapor or H2 gas passes through the suppression pool and can be handled in the gas phase of the wet well. At this time, the water vapor is condensed in the suppression pool, thereby suppressing the pressure increase in the dry well.

(Problem to be solved by the invention) On the other hand, a dry well is filled with non-condensable gas such as N2 gas, and if water vapor or H2 gas is generated during an accident, non-condensable gas such as N2 gas will be released together with these gases. Condensable gas flows into the wet well through the absorption pool. In the suppression pool, the water vapor that flows in is condensed by the pool water, but non-condensable gas such as N2 gas does not condense in the suppression pool, so it passes through the suppression pool and accumulates in the gas phase of the wet well. . If this happens, the pressure in the wet well will rise, and it is expected that the pressure in the dry well will rise accordingly.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the amount of gas sealed in the dry well as much as possible.
An object of the present invention is to provide a reactor containment vessel configured to condense water vapor generated during an accident by scrubbing and reduce the pressure in a wet well.

[Structure 1 of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention provides an atomic system in which a dry well housing a reactor pressure vessel and a wet well having a suppression pool are connected by a vent pipe. In the reactor containment vessel, a water vapor generator is installed in the dry well so that the temperature and water vapor partial pressure of the dry well gas phase are sufficiently higher than the temperature and water vapor partial pressure of the suppression pool. It is something to do.

(Function) According to the reactor containment vessel of the present invention, since the temperature and water vapor partial pressure of the gas phase part of the dry well are made higher than the temperature and water vapor partial pressure of the suppression pool, N2 gas, 02 gas, etc. This reduces non-condensable gases, making it easier to deactivate the reactor containment vessel in the event of an accident, and condenses steam through scrubbing in a low-temperature suppression pool, keeping the pressure rise inside the reactor containment vessel low. It will be done.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of one embodiment of the present invention.

As shown in the figure, a pedestal 2 is constructed on a base 1, and a reactor pressure vessel 3 containing a reactor core (not shown) is installed at the upper end of the pedestal 2. A radiation shielding wall 4 is provided around the reactor pressure vessel 3. Further, a pedestal cavity 5 is formed between the inside of the pedestal 2 and the lower part of the reactor pressure vessel 3. It is composed of a dry well 7 that houses the reactor pressure vessel 3 and the radiation shielding wall 4, and a wet well 8 that has a torus-shaped suppression pool 9. The reactor containment vessel 6 is installed to prevent the atmosphere from dissipating to the outside. ing. The dry well 7 and wet well 8 are connected to the vent pipe 10.
The tip of the vent pipe 10 opens into the water of the suppression pool 9.

Therefore, in the present invention, the water vapor generator 11 is installed at an appropriate location in the dry well 7, in the figure below the radiation shielding wall 4, and the temperature and water vapor partial pressure of the gas phase of the dry well 7 are adjusted to the suppression pool 9. It is configured to be sufficiently higher than the temperature and water vapor partial pressure. There is a puddle at 12.

Next, the superior effect of the present invention will be explained in comparison with the conventional example with reference to FIG. Note that the temperature and water vapor partial pressure of both suppression pools are the same at 40° C. and 0%, respectively.

FIG. 2a is a diagram showing changes in the dry well pressure of the reactor containment vessel of the present invention, and the humidity is 100%.

The temperature and water vapor partial pressure of the gas phase of the dry well at approximately 1 atm were set to 95°C and 80%, respectively (N2.02 was 20%
%) shows the change in the dry well pressure of the reactor containment vessel after the accident occurred.

On the other hand, Figure 2 shows the change in dry well pressure in a conventional reactor containment vessel. This figure shows the change in the dry well pressure of the reactor containment vessel after the accident occurred under the conditions of C and 20% (N2°02 is 80%).

As can be seen from Figures 2a and b, the dry well pressure of the present invention increases more slowly after the accident than the conventional example, and the dry well pressure of the present invention after 5 hours is also lower than that of the conventional example. It was found that it was about 1/3 lower than that of the previous year.

[Effects of the Invention] As explained above, according to the present invention, the partial pressure and temperature of water vapor in the dry well are sufficiently higher than the partial pressure and temperature of water vapor in the suppression pool.
This reduces the amount of non-condensable gases such as 2 gases, which makes it easier to deactivate the reactor containment vessel in the event of an accident. It has the excellent effect of keeping the pressure rise low.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, and FIG. 2 is a graph comparing the pressure of the dry well of the reactor containment vessel of the present invention and a conventional example. 1... Base 2... Pedestal 3... Reactor pressure vessel 4... Radiation shielding wall 5... Pedestal cavity 6... Reactor containment vessel 7... Dry well 8... Wet Well 8 9...Napletion pool 10...Vent pipe 11...Steam generator 12...Water pool (8733) Agent Patent attorney Yoshiaki Inomata (Idiot)
1 person) Figure 1 (a) (b) Figure 2

Claims (1)

[Claims] (1) In a reactor containment vessel in which a dry well housing a reactor pressure vessel and a wet well having a suppression pool are connected by a vent pipe, the temperature and water vapor partial pressure of the dry well gas phase are controlled by the temperature and water vapor partial pressure of the suppression pool. A nuclear reactor containment vessel characterized in that a steam generator is installed so that the temperature and partial pressure of steam are sufficiently higher than that of the reactor containment vessel.