JP2012230057A - Decompression device of containment vessel and decompression method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decompression device or the like of a containment vessel capable of venting gas in the containment vessel at any pressure level and further of venting the gas in the containment vessel even when station blackout and loss of air pressure that is a driving source for air-operated valves occur.SOLUTION: A decompression device of a containment vessel includes: an exhaust pipe that transfers gas in the containment vessel to an exhaust tower and exhausts the gas; a self-opening type first isolating valve that performs opening operation by using gas pressure in the exhaust pipe as a driving source and allows the gas to be transferred through the exhaust pipe; a self-opening type first isolating valve driving line that has a pressure guiding pipe for introducing gas in the exhaust pipe to a driving part of the self-opening type first isolating valve and a valve driven by DC power supply; a self-opening type second isolating valve that is disposed downstream from the self-opening type first isolating valve of the exhaust pipe and performs opening operation by using the gas pressure in the exhaust pipe as the driving source; and a self-opening type second isolating valve driving line that has a pressure guiding pipe for introducing the gas in the exhaust pipe to a driving part of the self-opening type second isolating valve and a valve driven by DC power supply.

Description

  The present invention relates to a nuclear reactor, and in particular, when an alternative water injection to the reactor pressure vessel and the containment vessel is urgently required, the pressure inside the containment vessel where the pressure is increased is set to an arbitrary pressure level. The present invention relates to a reactor containment vessel decompression device and a decompression method that are decompressed and can be injected with a pump having a low discharge pressure.

  Conventionally, in a boiling water reactor (BWR), an electric valve and a rupture disk that bursts when the set burst pressure is reached are arranged in series in the exhaust pipe, and the pressure in the reactor containment vessel rises abnormally. At the same time, a mechanism for venting the gas in the reactor containment vessel to the atmosphere is known (for example, see Patent Document 1).

  FIG. 4 shows a schematic configuration of a Mark-I type BWR as an example of such a boiling water reactor (BWR). As shown in FIG. 4, the reactor pressure vessel 1 is built in a steel reactor containment vessel 2.

  The Mark-I type BWR reactor containment vessel 2 includes a reactor pressure vessel 1 and a flask-type dry well 3 surrounding a recirculation system (not shown), and a donut-type suppression chamber concentrically disposed below the flask-type dry well 3. 4, a plurality of vent pipes 5 that radially connect the dry well 3 and the suppression chamber 4, a donut-shaped vent header 6 connected to the tip of the vent pipe 5 in the internal space of the suppression chamber 4, and the vent header 6 It is comprised from the pressure suppression system, such as several downcomer pipes 7. FIG.

  The suppression chamber 4 is filled with pool water, and the tip portion of the downcomer pipe 7 is submerged below the surface of the water.

  The leading end of the main steam escape pipe 10 extending from the main steam relief safety valve 9 attached to the main steam system pipe 8 is also led to the surface of the suppression chamber 4.

  When the pressure in the reactor pressure vessel 1 rises excessively, the main steam relief safety valve 9 is operated to release a part of the steam from the reactor pressure vessel 1 into the pool water of the suppression chamber 4. Thus, the pressure rise in the reactor pressure vessel 1 is suppressed.

  The pool water in the suppression chamber 4 is cooled and circulated by the residual heat removal system (RHR), but this residual heat removal system does not function properly. After the main steam relief valve is opened, it is closed due to equipment failure. When accidents such as failure do not occur, the pressure and temperature in the reactor containment vessel 2 rapidly increase, and finally there is a risk of exceeding the design limit of the reactor containment vessel 2.

  An emergency gas processing system (SGTS) 14 is provided as a facility for safely processing a gas containing a radioactive substance released into the reactor containment vessel 2. The emergency gas treatment system 14 includes a moisture removal device, a high performance particle filter, an iodine charcoal filter, an exhaust fan, etc. (not shown).

  An exhaust pipe 12 that communicates between the suppression chamber 4 and the exhaust tower 15 is disposed in the suppression chamber 4 of the reactor containment vessel 2. The exhaust pipe 12 is for transferring the gas in the reactor containment vessel 2 to the exhaust tower 15 and releasing it to the atmosphere. In the exhaust pipe 12, a suppression chamber side first isolation valve 11, a motor operated valve (MO) 16, and a rupture disk 17 each including a pneumatically driven valve are arranged in this order from the upstream side.

  Further, a branch exhaust pipe 12a branched from the suppression chamber side first isolation valve 11 and the motor operated valve 16 of the exhaust pipe 12 and connected to the dry well 3 is disposed. Is provided with a dry well side first isolation valve 11a. The exhaust pipe 12 and the branch exhaust pipe 12a are pressure-resistant piping.

  Further, a purge pipe 18 branched from the suppression chamber side first isolation valve 11 of the exhaust pipe 12 and the motor operated valve (MO) 16 and connected to the exhaust tower 15 via the emergency gas processing system 14 is provided. The purge pipe 18 is provided with a second isolation valve 13 that is pneumatically driven. The purge pipe 18 is composed of a normal pipe having a lower pressure resistance than that of the pressure resistant pipe.

  When the pressure inside the reactor containment vessel 2 is normal and the inside of the reactor containment vessel 2 is purged with nitrogen gas, the suppression chamber side first isolation valve 11 and the second isolation valve 13 are opened remotely, After the gas in the suppression chamber 4 is processed by the emergency gas processing system 14 to remove radioactive substances and the like, it is discharged from the exhaust tower 15 at a high place.

  On the other hand, if there is a possibility that the pressure and temperature of the reactor containment vessel 2 will suddenly rise and damage the reactor containment vessel 2, the suppression chamber side first isolation valve 11 or the dry well side first isolation valve will be described. 11a and the motor-operated valve 16 are opened by remote control. As a result, when the pressure of the gas in the exhaust pipe 12 reaches the preset burst pressure of the rupture disk 17, the rupture disk 17 bursts and high pressure gas is rapidly released, and the reactor containment vessel 2 of the reactor containment vessel 2 due to overpressure is released. Damage is prevented.

  By the way, in such a reactor in which the conventional rupture disk 17 is ruptured so as to prevent overpressure leading to damage to the reactor containment vessel 2, the rupture set pressure of the rupture disc 17 is the maximum operating pressure of the reactor containment vessel 2. Since it is set to the above pressure, the gas in the reactor containment vessel 2 below this pressure cannot be vented.

  Therefore, in the event of an urgent need for alternative water injection to the reactor core, such as during a reactor coolant loss accident (LOCA), only pumps with discharge pressures greater than the maximum operating pressure of the containment vessel should be used. There was a problem that the pump procurement range was limited.

  The motor operated valve 16 is driven by an AC power source, and the suppression chamber side first isolation valve 11 and the dry well side first isolation valve 11a are driven by air pressure and controlled by a control power source (DC power source). For this reason, either the total AC power loss (SBO) in which the loss of the external power supply and the emergency power supply overlap, the loss of the air pressure that is the drive source of the air operated valve, or the loss of the control power supply (DC power supply) for valve control In the case where a stagnation occurs, there is a possibility that the gas in the reactor containment vessel 2 cannot be vented.

Japanese Patent Laid-Open No. 3-235093

  In the conventional technology for preventing damage to the reactor containment vessel due to overpressure by rupture of the rupture disk, the burst set pressure of the rupture disk is set to a pressure higher than the maximum use pressure of the containment vessel. When urgent alternative water injection was required, only pumps having discharge pressures higher than the maximum operating pressure of the containment vessel could be used, and there was a problem that the pump procurement range was limited.

  In addition, if either all AC power loss (SBO), loss of air pressure, which is the driving source of the air operated valve, or loss of control power supply (DC power supply) for valve control occurs, the reactor is stored. There was a possibility that the gas in the container 2 could not be vented.

  The present invention has been made to solve such a conventional problem, and can vent the gas in the reactor containment vessel at an arbitrary pressure level, and also loses all AC power and drives the air-operated valve. An object of the present invention is to provide a depressurization apparatus and depressurization method for a reactor containment vessel that can vent the gas in the reactor containment vessel even when air pressure loss occurs.

  One aspect of the pressure reduction device for a reactor containment vessel according to the present invention is connected to a suppression chamber of a reactor containment vessel that contains a reactor pressure vessel, and transfers the gas in the reactor containment vessel to an exhaust tower to the atmosphere. An exhaust pipe to be discharged, a self-opening / closing first isolation valve that opens by using the gas pressure on the reactor containment vessel side in the exhaust pipe as a driving source, and allows gas transfer through the exhaust pipe, and the exhaust pipe The first pressure guiding pipe for introducing the gas upstream from the self-closing on / off type first isolation valve to the drive part of the self-closing on / off type first isolation valve and the first pressure inserted into the first pressure guiding pipe A self-closing on / off type first isolation valve driving line having a DC power supply driving valve, and disposed on the downstream side of the self-closing on / off type first isolation valve of the exhaust pipe, on the reactor containment vessel side in the exhaust pipe Self-opening / closing type 2 that opens with gas pressure as the driving source A second pressure guiding pipe for introducing a gas upstream of the self-closing on / off type second isolation valve of the exhaust pipe into the driving unit of the self-closing on / off type second isolation valve; and the second pressure guiding pipe And a second isolation valve drive line having a second DC power supply drive valve interposed between the first and second power supply valves.

  One aspect of the method for depressurizing a reactor containment vessel according to the present invention is connected to a suppression chamber of a reactor containment vessel containing a reactor pressure vessel, and transfers the gas in the reactor containment vessel to an exhaust tower to the atmosphere. An exhaust pipe to be discharged, a self-opening / closing first isolation valve that opens by using the gas pressure on the reactor containment vessel side in the exhaust pipe as a driving source, and allows gas transfer through the exhaust pipe, and the exhaust pipe The first pressure guiding pipe for introducing the gas upstream from the self-closing on / off type first isolation valve to the drive part of the self-closing on / off type first isolation valve and the first pressure inserted into the first pressure guiding pipe A self-closing on / off type first isolation valve driving line having a DC power supply driving valve, and disposed on the downstream side of the self-closing on / off type first isolation valve of the exhaust pipe, on the reactor containment vessel side in the exhaust pipe A self-opening / closing second gap that opens using gas pressure as the drive source A valve, a second pressure guiding pipe for introducing a gas upstream of the self-closing on / off type second isolation valve of the exhaust pipe into a drive unit of the self-powering on / off type second isolation valve, and the second pressure guiding pipe A self-closing on / off-type second isolation valve driving line having a second DC power supply driving valve inserted therein, and energizing the first DC power supply driving valve and the second DC power supply driving valve. By opening the valve, the gas in the reactor pressure vessel is released to the atmosphere through the exhaust pipe.

  According to the present invention, it is possible to vent the gas in the reactor containment vessel at an arbitrary pressure level, and also when the loss of all the AC power supply and the loss of air pressure that is the drive source of the air operation valve occur. It is possible to provide a depressurizing device and a depressurizing method for a reactor capable of venting a gas in a reactor containment vessel.

The figure which shows typically the principal part structure of 1st Embodiment of this invention. The figure which shows typically the principal part structure of 2nd Embodiment of this invention. The figure which shows the structure of an isolation valve typically. The figure which shows typically the principal part structure of the conventional nuclear reactor.

  Next, an embodiment in which the present invention is applied to a Mark-I boiling water reactor will be described with reference to the drawings.

  FIG. 1 is a system diagram showing a schematic configuration of a main part of a nuclear reactor according to the first embodiment of the present invention. 1, parts corresponding to those of the conventional reactor containment decompression device shown in FIG.

  The nuclear reactor shown in FIG. 1 is a so-called Mark-I type BWR, and is composed mainly of a dry well 3 and a pressure suppression system such as a suppression chamber 4, a vent pipe 5, a vent header 6, and a downcomer pipe 7. ing.

  The reactor containment vessel 2 is provided with an exhaust pipe 12 that passes through the suppression chamber 4 and opens into the internal space, and a branch exhaust pipe 12a that branches from the exhaust pipe 12 and passes through the dry well 3 and opens into the internal space. Has been. The exhaust pipe 12 is provided with a suppression chamber side first isolation valve 11 made of a normal pneumatic drive valve. In addition, a purge valve 20 comprising a normal pneumatically driven valve and a self-closing on / off type first isolation valve 21 comprising a self-operating air-operating valve are arranged in parallel so as to bypass the suppression chamber side first isolation valve 11. Has been. The purge valve 20 has a smaller capacity than the suppression chamber side first isolation valve 11 and the self-operating first isolation valve 21, and is opened when purging the reactor containment vessel 2 with nitrogen gas during normal operation. It is.

  The self-opening / closing first isolation valve 21 opens by using the gas pressure on the reactor containment vessel 2 side in the exhaust pipe 12 as a driving source, and allows the gas to be transferred through the exhaust pipe 12. The self-opening / closing first isolation valve 21 has a pressure guiding pipe 22 a for introducing a gas upstream of the self-opening / closing first isolation valve 21 of the exhaust pipe 12 into the drive unit of the self-opening / closing first isolation valve 21. And a self-opening / closing first isolation valve driving line 22 having a direct current power supply valve 22b inserted in the pressure guiding pipe 22a and driven by a direct current power supply.

  A self-opening / closing second isolation valve 31 comprising a self-opening / closing air-operating valve is disposed downstream of the exhaust pipe 12 from the self-opening / closing first isolation valve 21. The self-closing on / off-type second isolation valve 31 opens by using the gas pressure on the reactor containment vessel 2 side in the exhaust pipe 12 as a drive source, and allows the transfer of gas through the exhaust pipe 12. In this self-closing on / off type second isolation valve 31, a pressure guiding pipe 32 a for introducing a gas upstream of the self-closing on / off type second isolation valve 31 of the exhaust pipe 12 into the drive part of the self-closing on / off type second isolation valve 31. And a self-opening / closing second isolation valve drive line 32 having a DC power supply drive valve 32b inserted in the pressure guiding pipe 32a and driven by a DC power supply.

  Further, the branch exhaust pipe 12a branched from the exhaust pipe 12 and opened to the internal space of the dry well 3 is opened by using the gas pressure in the branch exhaust pipe 12a on the dry well 3 side as a drive source, and the branch exhaust pipe 12a is opened. Also, a dry well side self-closing first isolation valve 23 that allows gas transfer through the exhaust pipe 12 is provided. In the dry well side self-closing first isolation valve 23, the gas upstream of the dry well side self-closing first isolation valve 23 of the branch exhaust pipe 12a is driven to drive the dry well side self-closing first isolation valve 23. A dry well side self-opening / closing first isolation valve driving line 24 having a pressure guiding pipe 24a for introduction into the section and a DC power supply driving valve 24b inserted in the pressure guiding pipe 24a is provided.

  Further, a purge side self-closing on / off type second isolation valve 33 comprising a self-opening / closing type air operating valve is provided in the purge pipe 18 branched from the exhaust pipe 12 and connected to the exhaust tower 15 via the emergency gas processing system 14. It is arranged. In the purge side self-closing on / off type second isolation valve 33, the gas upstream of the purge side self-closing on / off type second isolation valve 33 in the purge pipe 18 is introduced into the drive unit of the purge side self-closing on / off type second isolation valve 33. A purge side self-closing on / off type second isolation valve driving line 34 having a pressure guiding pipe 34a for connecting to the pressure guiding pipe 34a and a DC power source driving valve 34b that is driven by a DC power source is provided.

  A downstream side of the purge side self-closing on / off type second isolation valve 33 of the purge pipe 18 is a self-opening / closing type air operated valve, and the gas pressure on the purge side self-closing on / off type second isolation valve 33 side of the purge pipe 18 is driven. As shown, a purge pipe closing valve 37 that is closed is provided. The purge pipe blocking valve 37 includes a purge pipe blocking valve drive line 38 having a pressure guiding pipe for introducing a gas upstream of the purge pipe blocking valve 37 of the purge pipe 18 into the drive section of the purge piping blocking valve 37. Is arranged.

  The purge pipe closing valve 37 is normally open, and when the purge side self-closing second isolation valve 33 is opened, the pressure in the purge pipe 18 rises and exceeds the pressure resistance of the purge pipe 18. When the pressure is reached, the gas is automatically closed by the pressure of the gas.

  The purge pipe 18 is provided with a bypass pipe 18 a that bypasses the emergency gas treatment system 14 and is connected to the exhaust tower 15. The bypass pipe 18a is provided with a bypass-side self-closing on / off-type second isolation valve 35 made up of a self-opening / closing air-operating valve. In this bypass side self-closing on / off type second isolation valve 35, the gas upstream of the bypass side self-powering on / off type second isolation valve 35 of the bypass pipe 18a is introduced into the drive unit of the bypass side self-power on / off type second isolation valve 35. A bypass side self-closing on / off-type second isolation valve driving line 36 having a pressure guiding pipe 36a and a DC power supply driving valve 36b inserted in the pressure guiding pipe 36a and driven by a DC power supply is disposed.

  On the downstream side of the bypass side self-closing on / off type second isolation valve 35 of the bypass pipe 18a, a self-opening / closing type air operating valve is provided, and the gas pressure on the bypass side self-closing on / off type second isolation valve 35 side of the bypass pipe 18a is driven. As shown in FIG. The bypass pipe closing valve 39 includes a bypass pipe closing valve drive line 40 having a pressure guiding pipe for introducing a gas upstream of the bypass pipe closing valve 39 of the bypass pipe 18 a into the drive unit of the bypass pipe closing valve 39. Is arranged.

  The bypass pipe closing valve 39 is normally open. When the bypass side self-closing second isolation valve 35 is opened, the pressure in the purge pipe 18 rises and exceeds the pressure resistance of the purge pipe 18. When the pressure is reached, the gas is automatically closed by the pressure of the gas.

  In the first embodiment having the above-described configuration, a self-closing on / off type first isolation valve 21, a dry well side self-closing on / off type first isolation valve 23, a self-closing on / off type second isolation valve 31 and a purge-side self-powering unit comprising self-opening / closing type air valves The on / off-type second isolation valve 33 and the bypass side self-closing on / off-type second isolation valve 35 use the gas pressure in the reactor containment vessel 2 as the driving force. The DC power supply drive valves 22b, 24b, 32b, 34b, and 36b provided in these self-opening / closing air valves are driven by a DC power supply that is a control power supply. If the DC power supply is lost, the battery It can be driven by a DC power source supplied from (storage battery, dry battery).

  Therefore, even in the event of all loss of AC power supply (SBO), loss of air pressure as the drive source of the air operated valve, and loss of control power supply (DC power supply) for valve control in the event of an emergency, the DC power supply drive valve By switching the direct current power supplied to 22b, 24b, 32b, 34b, 36b to a direct current power source from a battery such as a dry cell, the above-mentioned first self-opening / closing first isolation valve 21 and drywell side self-opening / closing first isolation The valve 23, the self-closing second isolation valve 31, the purge-side self-closing second isolation valve 33, and the bypass-side self-closing second isolation valve 35 can be operated to vent the gas in the reactor containment vessel 2. Can be done.

  In the event of an emergency, when it becomes necessary to vent the gas from the reactor containment vessel 2, first, the gas from which the radioactive material has been removed to some extent is vented by passing through the pool water from the suppression chamber 4 side. In this case, when the pressure in the reactor containment vessel 2 is not high, the first self-opening / closing first isolation valve 21 and the purge side self-closing second isolation valve 33 are opened and the emergency gas treatment system 14 is passed through. Vent the gas. In this case, the gas that has been processed by the emergency gas processing system 14 and from which the radioactive material has been removed is sent to the exhaust tower 15 and released at a high place.

  On the other hand, when the pressure in the reactor containment vessel 2 is already high and the emergency gas treatment system 14 cannot be used due to pressure resistance, the self-opening / closing first isolation valve 21 and the self-operating opening / closing second By opening the isolation valve 31, the gas in the reactor containment vessel 2 is vented. Furthermore, when the water level in the suppression chamber 4 rises above a certain level, the dry well side self-closing first isolation valve 23 and the self-closing second isolation valve 31 are not the self-closing first isolation valve 21. Is opened, the gas in the reactor containment vessel 2 is vented.

  By venting the gas in the reactor containment vessel 2 as described above and reducing the pressure in the reactor containment vessel 2, water can be injected into the reactor pressure vessel 1 without using a high-pressure pump. Can be done. Therefore, as in the case of the loss of reactor coolant accident (LOCA), it is necessary to perform an urgent and large amount of alternative water injection into the reactor pressure vessel 1, but the discharge pressure is higher than the pressure in the reactor containment vessel 2. When sufficient water injection cannot be performed with only a high pump, the gas in the reactor containment vessel 2 can be vented under an arbitrary pressure without being limited to the burst pressure of the rupture disk as in the prior art. Water can be injected by a pump having a low discharge pressure.

  In the above description, when the air pressure for opening the suppression chamber side first isolation valve 11 and the purge valve 20 is secured, the suppression chamber side first isolation valve is not the self-opening / closing type first isolation valve 21. 11 or the purge valve 20 may be opened.

  Incidentally, as described above, the DC power supply drive valves 22b, 24b, 32b, 34b, and 36b are configured to be driven by a DC power supply supplied from a battery (storage battery, dry battery). 21, the dry well side self-closing first isolation valve 23, the self-closing second isolation valve 31, the purge side self-closing second isolation valve 33, and the bypass side self-closing second isolation valve 35 are kept open. Therefore, it is necessary to continue supplying DC power to the DC power supply drive valves 22b, 24b, 32b, 34b, and 36b.

  On the other hand, for example, as shown in FIG. 3, the self-standing open / close air valve includes a valve casing 101 that houses a valve body (not shown), a valve rod 102 that is provided with a valve body at the tip, and a valve rod 102. The main part is composed of a spring 103 for biasing, a diaphragm 104 to which driving air is introduced, and the like. Therefore, when the valve stem 102 moves and the valve body is in an open state, a locking member (so-called gag or the like) that keeps the positions of the valve casing 101 and the flange portion 105 of the valve stem 102 mechanically constant. ) When the DC power supply to the DC power supply drive valves 22b, 24b, 32b, 34b, and 36b is stopped by inserting 110, the self-opening / closing first isolation valve 21 and the drywell side self-opening / closing The first isolation valve 23, the self-closing second isolation valve 31, the purge side self-closing second isolation valve 33, and the bypass side self-closing second isolation valve 35 can be maintained in the open state.

  Further, if the locking member 110 is electrically driven so that it can be inserted and pulled out, the self-opening / closing first isolation valve 21 and the drywell side self-closing first isolation can be obtained by pulling out the locking member 110. The valve 23, the self-closing second isolation valve 31, the purge side self-closing second isolation valve 33, and the bypass side self-closing second isolation valve 35 can be closed.

  FIG. 2 is a system diagram showing a schematic configuration of a main part of a nuclear reactor according to the second embodiment. In FIG. 2, parts corresponding to those of the nuclear reactor according to the first embodiment shown in FIG.

  As shown in FIG. 2, in the second embodiment, the suppression chamber side first isolation valve 11 including the air-driven valve in the first embodiment is omitted, and the purge pipe closing valve 38 and the bypass pipe closing valve 39 are omitted. Is. Even in such a configuration, as in the case of the first embodiment, the loss of all AC power (SBO), the loss of air pressure, which is the drive source of the pneumatic valve, and the loss of the control power (DC power) for valve control Even when all of these occur, each self-closing first isolation valve 21, drywell side self-closing first isolation valve 23, self-closing second isolation valve 31, purge side self-closing second isolation valve 33, The bypass-side self-closing second isolation valve 35 can be operated, and the gas in the reactor containment vessel 2 can be vented.

  In addition, although the above embodiment demonstrated the case where this invention was applied to Mark-I type BWR, this invention should not be limited to this embodiment, The reactor of Mark-II type BWR or ABWR The same can be applied to the decompression device for the containment vessel.

  1 ... Reactor pressure vessel, 2 ... Reactor containment vessel, 3 ... Dry well, 4 ... Suppression chamber, 5 ... Vent pipe, 6 ... Vent header, 7 ... Downcomer pipe, 8 ... Main steam system piping, 9 ... Main steam relief safety valve, 10 ... Main steam relief pipe, 11 ... Suppression chamber side first isolation valve, 11a ... Dry well side first isolation valve, 12 ... Exhaust pipe, 12a ... branch exhaust pipe, 13 ... second isolation valve, 14 ... emergency gas treatment system (SGTS), 12a, 12b ... first isolation valve, 15 ... exhaust tower, 16 ... motorized valve, 17 ... ... Rupture disk, 18 ... Purge piping, 18a ... Bypass piping, 20 ... Purge valve, 21 ... Self-opening / closing first isolation valve, 22a, 24a, 32a, 34a, 36a ... Pressure guiding piping, 22b, 24b, 32b, 3 b, 36b... DC power supply drive valve, 22... Self-actuated first isolation valve drive line, 24... Drywell side self-actuated first isolation valve drive line, 31. Valve 32. Self-opening and closing second isolation valve drive line 33. Purge side self-opening and closing second isolation valve 34. Purge side self-opening and closing second isolation valve driving line 35 35 Bypass side. Self-opening / closing second isolation valve, 36 …… Bypass side self-closing on / off type second isolation valve drive line, 37 …… Purge piping blocking valve, 38 …… Purge piping blocking valve driving line, 39 …… Bypass piping blocking valve , 40 …… Bypass piping block valve drive line.

Claims (9)

An exhaust pipe connected to a suppression chamber of a reactor containment vessel containing a reactor pressure vessel, and transferring the gas in the reactor containment vessel to an exhaust tower and releasing it to the atmosphere;
A self-opening / closing first isolation valve that opens by using the gas pressure on the reactor containment vessel side in the exhaust pipe as a drive source and allows gas transfer through the exhaust pipe;
A first pressure guiding pipe for introducing gas upstream of the self-closing on / off type first isolation valve of the exhaust pipe to the drive unit of the self-powering on / off type first isolation valve is inserted into the first pressure guiding pipe. A first isolation valve driving line having a first DC power supply driving valve;
A self-opening / closing second isolation valve disposed downstream of the self-opening / closing first isolation valve of the exhaust pipe and opening with the gas pressure on the reactor containment vessel side in the exhaust pipe as a drive source;
The exhaust pipe is inserted into a second pressure guiding pipe for introducing a gas upstream of the self-closing on / off type second isolation valve to a drive unit of the self-powered on / off type second isolation valve, and the second pressure guiding pipe. A self-opening / closing second isolation valve driving line having a second DC power supply driving valve;
A depressurizing device for a reactor containment vessel, comprising: A branch exhaust pipe that branches from between the self-closing first isolation valve and the self-closing second isolation valve of the exhaust pipe and connected to a dry well of the reactor containment vessel;
A dry well-side self-closing first isolation valve that opens by using the gas pressure on the reactor containment vessel side in the branch exhaust pipe as a drive source and allows gas transfer through the branch exhaust pipe;
A third pressure guiding pipe for introducing a gas upstream of the dry well side self-closing first isolation valve of the branch exhaust pipe into the drive unit of the dry well side self-closing first isolation valve; A dry well side self-closing first isolation valve driving line having a third DC power supply driving valve inserted in the pressure guiding pipe;
The reactor containment vessel decompression device according to claim 1, comprising: A purge pipe branched from the self-closing first isolation valve and the self-closing second isolation valve of the exhaust pipe and connected to an emergency gas treatment system;
A purge-side self-closing second isolation valve that is inserted into the purge pipe and opens using the gas pressure on the reactor containment vessel side in the purge pipe as a drive source;
A fourth pressure guiding pipe and a fourth pressure guiding pipe for introducing a gas upstream of the purge side self-closing on / off type second isolation valve of the purge pipe to a drive portion of the purge side self-powering on / off type second isolation valve. A purge side self-closing on / off type second isolation valve drive line having a fourth DC power supply drive valve inserted in
The pressure reducing device for a reactor containment vessel according to claim 1 or 2, further comprising: a purge valve that is inserted into a pipe that bypasses the self-opening / closing first isolation valve and is driven by air pressure from the outside. A part of the exhaust pipe where the first self-closing on / off type isolation valve is disposed is a first isolation valve driven by air pressure from the outside in parallel with the self-powering on / off type first isolation valve and the purge valve. The reactor containment vessel decompression device according to claim 3, further comprising: A bypass pipe branched from the purge pipe and bypassing the emergency gas treatment system;
A bypass-side self-closing on / off-type second isolation valve that is inserted into the bypass pipe and opens using the gas pressure on the reactor containment vessel side in the bypass pipe as a drive source;
A fifth pressure guiding pipe and a fifth pressure guiding pipe for introducing a gas upstream of the bypass side self-closing on / off type second isolation valve into the drive unit of the bypass side self-closing on / off type second isolation valve. A bypass side self-closing on / off type second isolation valve drive line having a fifth DC power supply drive valve interposed in
The reactor containment vessel decompression device according to claim 3, wherein the reactor containment vessel pressure reduction device is provided. A purge pipe closing valve provided downstream of the purge side self-closing on / off type second isolation valve of the purge pipe and closing with the gas pressure on the purge side self-closing on / off type second isolation valve side of the purge pipe as a drive source When,
A purge pipe closing valve drive line having a sixth pressure guiding pipe for introducing a gas upstream of the purge pipe closing valve of the purge pipe into a drive portion of the purge pipe closing valve;
A bypass pipe closing valve provided downstream of the bypass side self-closing on / off type second isolation valve of the bypass pipe and closing with the gas pressure on the bypass side self-closing on / off type second isolation valve side of the bypass pipe as a drive source; ,
A bypass pipe closing valve drive line having a seventh pressure guiding pipe for introducing a gas upstream of the bypass pipe closing valve of the bypass pipe into a drive portion of the bypass pipe closing valve;
The reactor containment vessel decompression device according to claim 5, comprising: The decompression device for a nuclear reactor containment vessel according to any one of claims 1 to 6, wherein the first to fifth DC power supply drive valves are capable of being driven by a DC power supply from a battery. At least the first self-opening / closing first isolation valve and the second self-opening / closing isolation valve have a mechanism for mechanically restricting movement of the valve rod in the open state and maintaining the open state. Item 8. A reactor containment depressurization apparatus according to any one of Items 1 to 7. An exhaust pipe connected to a suppression chamber of a reactor containment vessel containing a reactor pressure vessel, and transferring the gas in the reactor containment vessel to an exhaust tower and releasing it to the atmosphere;
A self-opening / closing first isolation valve that opens by using the gas pressure on the reactor containment vessel side in the exhaust pipe as a drive source and allows gas transfer through the exhaust pipe;
A first pressure guiding pipe for introducing gas upstream of the self-closing on / off type first isolation valve of the exhaust pipe to the drive unit of the self-powering on / off type first isolation valve is inserted into the first pressure guiding pipe. A first isolation valve driving line having a first DC power supply driving valve;
A self-opening / closing second isolation valve disposed downstream of the self-opening / closing first isolation valve of the exhaust pipe and opening with the gas pressure on the reactor containment vessel side in the exhaust pipe as a drive source;
The exhaust pipe is inserted into a second pressure guiding pipe for introducing a gas upstream of the self-closing on / off type second isolation valve to a drive unit of the self-powered on / off type second isolation valve, and the second pressure guiding pipe. A self-opening / closing second isolation valve driving line having a second DC power supply driving valve;
The gas in the reactor pressure vessel is released to the atmosphere through the exhaust pipe by energizing and opening the first DC power supply drive valve and the second DC power supply drive valve. A depressurizing method for a reactor containment vessel.

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