JPH02253193A - Vent system for steam condenser - Google Patents

Abstract

PURPOSE:To stabilize the condensation of steam by providing a steam condenser submerged in a cooling pool and providing a condensate line of the steam condenser with a jet scrubber. CONSTITUTION:In a vent system, a main steam pipe 5 is quickly cut off at the time of an accident of loss of a cooling material. Steam in a reactor pressure vessel 2 is led to a steam condenser 8 through a steam supply line 7 and is condensed and is returned to the nuclear reactor pressure vessel 2. When an emergency reactor core cooling system is operated, the reactor pressure is temporarily made negative, and the condensing function is reduced when nitrogen is mixed into the condenser 8. In this case, a second remote control valve 11 is closed and a third remote control valve 13 and a fourth remote control valve 14 are opened to supply condensate to a jet scrubber 16, and nitrogen flowed from a nitrogen vent line 15 is discharged to a header tank, and water is stored in the header tank 17, and nitrogen is discharged to the periphery. Thus, steam is stably condensed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a vent system for a steam condenser that condenses steam from a nuclear reactor pressure vessel during a loss of coolant accident.

(Prior Art) A conventional vent system for a steam condenser will be described with reference to FIG. In FIG. 3, a reactor pressure vessel 2 containing a reactor core 1 includes a recirculation line 4 having a recirculation pump 3;
is provided. Note that although the recirculation line 4 is shown in a broken state in the figure, it is normally not broken. Reference numeral 5 denotes a main steam pipe, which branches off from the main steam pipe 5 and is connected to a steam supply line 7.

The steam condensing device 8 branches from the main steam pipe 5 that leads steam to the turbine, and is connected to a remote control valve 6 via a steam supply line 7. The steam condenser 8 is submerged in a cooling pool 9. A condensate line 10 connected below the steam condensing device 8 is connected to the reactor pressure vessel 2 via a remote control valve 11.

(Problems to be Solved by the Invention) In the reactor pressure vessel 2 and the recirculation pump 3 and recirculation line 4 that circulate the coolant in the reactor, a coolant loss accident in which the recirculation line 4 is damaged as shown in the figure occurs. If this occurs, the main steam pipe 5 is immediately shut off by the main steam valve 12. Next, by opening the remote control valve 6, the steam in the reactor pressure vessel 2 is guided to the steam condensing device 8 via the steam supply line 7, where it is condensed. Return to pressure vessel 2. Furthermore, the emergency cooling system that cools the reactor core 1 is activated, and the inside of the reactor pressure vessel 2 temporarily becomes negative pressure.
When the nitrogen filling the area around the reactor flows into the reactor pressure vessel 2 from the damaged part and reaches the steam condensing device 8, the condensing capacity of the steam condensing device 8 decreases, and the heat removal capacity reaches the specified performance. become unable.

The present invention has been made to solve the above-mentioned problems, and when the main steam piping leading steam to the turbine is isolated in the event of a loss of coolant accident in a nuclear reactor, the present invention can be installed on a piping branched from the main steam piping. The steam is condensed by a steam condenser. In addition, we provide a vent system for steam condensers that maintains the condensing capacity of steam condensers by removing nitrogen using a jet scrubber when nitrogen gets mixed into the steam condensers, and ensures continued operation after a loss of coolant accident. It's about doing.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a steam condensing device submerged in a cooling pool with one base end connected to a reactor main steam pipe and the other base end connected to a reactor condensate line, and a steam condensing device submerged in a cooling pool. diene l- in the condensate line of the equipment.
A scrubber is provided, a nitrogen pen 1 line is connected via a remote control valve between the diene 1 scrubber and the gas phase of the steam condensing device, and a header tank is provided below the jet scrubber. It is characterized in that the lower part of the header tank is connected to the condensate line.

(Function) For example, in the event of a loss of coolant accident, the isolation valve in the main steam pipe closes, the remote control valve opens, and the steam in the reactor pressure vessel flows into the steam condensing device from the steam supply line. Water condensed in this steam condenser returns to the reactor pressure vessel through a condensate line, but if nitrogen gets mixed into the steam condenser, it can be removed by a jet scrubber through a nitrogen vent line.

(Example) A first embodiment according to the present invention will be described with reference to FIG.

Note that the same parts as in FIG. 3 are designated by the same reference numerals, and the explanation of the overlapping parts will be omitted. A first remote control valve 6 and a steam supply line 7 branch from the main steam pipe 5 that leads steam to the turbine.
It is connected to the steam condensing device 8 via. The steam condenser 8 is submerged in a cooling pool 9. A condensate line [0] from below the steam condensing device 8 is connected to the reactor pressure vessel 2 via a second remote control valve 11. The other end is connected to a jet scrubber 16 via a third remote control valve 13. A line] 5 is connected to the jet scrubber 16 from the lower side (gas phase part) of the steam condensing device 8 to the fourth remote control valve 14 and the nitrogen vent 1. A header tank 17 is provided below the diene 1 to the scrubber 14, and the header tank 17 is connected to the reactor pressure vessel 2 via a condensate line 18.

Diene 1 to scrubber 16 are of the type that inject pressurized water or an appropriate aqueous solution from a nozzle to suck in the exhaust gas, and discharge only the purified gas by dissolving it in the liquid into the atmosphere. The action is almost the same as that used for purification.

In the above vent system, the main steam piping 5 is promptly shut off by the main steam isolation valve 12 in the event of a loss of coolant accident. Next, by opening the first remote control valve 6, the steam in the reactor pressure vessel 2 is guided to the steam condensing device 8 via the steam supply line 7, where it is condensed, and passed through the condensate line 10 to the second
It returns to the reactor pressure vessel 2 via the remote control valve 1. After the emergency core cooling system is activated, the reactor pressure temporarily becomes negative, and if nitrogen enters the steam condensing device 8, the condensing capacity decreases.

In this case, by closing the second remote control valve 11 and opening the third remote control valve 13 and fourth remote control valve 14, condensate from the steam condenser M8 is supplied to the jet scrubber 16 and the nitrogen vent line 15 is supplied to the jet scrubber 16. It entrains the nitrogen flowing in from the header tank 17 and releases the water to the header tank 17.
7 and the nitrogen is released into the surrounding area. header tank 17
The water returns to the reactor pressure vessel 2 via the condensate line. In this way, nitrogen mixed into the steam condenser 8 can be vented.

A second embodiment according to the present invention will be explained with reference to FIG.

The difference from the previous embodiment is that nitrogen released from the jet scrubber 14 is collected in a chamber 19 and sent to a suppression pool 20. The other parts are the same as those in the first embodiment, so the explanation of the overlapping parts will be omitted.

〔Effect of the invention〕

According to the present invention, the nitrogen that has flowed into the steam condensing device can be smoothly removed, and the steam condensing device can stably condense steam by removing heat, so that it can operate quickly and smoothly after a loss of coolant accident. can be done.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a first embodiment of a vent system for a steam condensing device according to the present invention, and FIG. 2 is a system diagram showing a vent system for a steam conditioning device according to a second embodiment of the present invention.
FIG. 3 is a system diagram showing a conventional steam condensing device system.

Claims (1)

[Claims] (1) A steam condensing device submerged in a cooling pool with one base end connected to the reactor main steam pipe and the other base end connected to the reactor condensate line, and a jet scrubber attached to the condensate line of this steam condensing device. A nitrogen vent line is connected between the jet scrubber and the gas phase of the steam condensing device via a remote control valve, and a header tank is provided below the jet scrubber, and a header tank is provided below the header tank. A vent system for a steam condenser that is connected to a condensate line.