JPS606897A - Fuel pool cooling and purifying system - 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 [Field of Application of the Invention] The present invention relates to improvements in fuel pool cooling and purification systems.

[Background of the invention]

The fuel pool installed inside the reactor building cools and stores spent fuel and fuel taken out from the reactor core in case of emergency, and maintains the quality of the pool water by removing impurities present in the water. There is a need.

Figure 1 is an overall system diagram showing a conventional example of a fuel pool cooling and purification system.
It is composed of a closed loop line and various valves that connect the sensor 6 and the above-mentioned parts.

Here, the cooling purification mode when spent fuel that is normally scheduled to be taken out is stored in the fuel pool 1 will be explained based on FIG. 2.

The pool water in the fuel pool 1 is heated by the decay heat of the spent fuel stored in the pool 1. After the heated pool water overflows into the skimmer surge tank 2, it is transported to the heat exchanger 5 by the pump 3 and cooled at the core. Note that the pool water is purified by a filter demineralizer 4 installed upstream of the heat exchanger 5. The pool water purified by the filtration demineralizer 4 and cooled by the heat exchanger 5 is returned to the fuel pool 1 through the line 7 and discharged to the bottom of the pool 1 via the sparger 6.

Next, the cooling purification mode when all the core fuel is stored in the fuel pool 1 in the event of a reactor emergency will be explained based on FIG. 3.

The heat exchanger 5 of the fuel pool cooling and purification system is designed to cool the spent fuel that is normally scheduled for removal. If the pool water temperature is stored at a temperature below the design value, the heat exchanger 5 of the fuel boule cooling and purification system described above cannot remove the decay heat of all the core fuel, and the pool water temperature cannot be kept below the design value.

However, conventionally, when all the core fuel is taken out into the fuel pool 1, the reactor residual heat removal system (reference numeral 100 in the figure)
200il-1゜ shows the pool water feed line from the fuel pool cooling and purification system to the reactor residual heat removal system, and the pool water return line from the reactor residual heat removal system to the fuel pool cooling and purification system) However, by guiding a portion of the pool water to the residual heat removal system, the insufficient capacity of the heat exchanger 5 is compensated for.

Figure 4 is an overall system diagram of the reactor residual heat removal system. This system is composed of a pump 8, a heat exchanger 9, etc., and is normally used to remove residual heat generated in the reactor core when the reactor is shut down. used. That is, by operating the pump 8 at the same time as the reactor is shut down, the reactor water is transported to the heat exchanger 9 through the line 10, and the reactor water that has been cooled by the heat exchanger 9 is transported through the line 11. ” - is returned to line 10.

On the other hand, in the event of a reactor emergency, if all the fuel taken out from the reactor core is stored in the fuel pool (numeral 1 in Figure 3), the fuel shown as numeral 5 in Figure 3 is The pool cooling and purification system heat exchanger alone cannot remove the decay heat of the entire core fuel. For this reason, conventionally, when all the core fuel was taken out into the fuel pool 1, the symbol 1 in FIG.
A portion of the pool water is sent from the line indicated by 00 to the line indicated by the same reference numeral (100) in FIG. 5, and the pool water is cooled by the heat exchanger 9 of the reactor residual heat removal system.

The pool water cooled by the heat exchanger 9 is shown at 20 in FIG.
The fuel is returned from the line indicated by 0 to the line indicated by the same reference numeral (200) in FIG. 3, and reaches the fuel pool 1.

As described above, conventionally, in the event of a nuclear reactor emergency, the heat exchanger of the reactor residual heat removal system is operated to compensate for the insufficient capacity of the heat exchanger of the fuel pool cooling and purification system.

However, as is clear from the above explanation, the reactor residual heat removal system has cooling capacity but not purification capacity, so it does not function to purify fuel pool water in the event of a reactor emergency. As always, they have no choice but to rely on the filtration and demineralizer of the fuel pool cooling and purification system.

[Purpose of the invention]

The present invention has been made in consideration of the following two points, and its purpose is to sufficiently provide not only the ability to cool the fuel pool water but also the ability to purify it in the event of an emergency in one nuclear reactor. The present invention seeks to provide an improved fuel bouquet cooling and purification system.

[Summary of the Invention] In order to achieve the above object, the present invention provides a fuel pool, a skimmer surge tank, a pump, a heat exchanger, a filtration demineralizer, and a closed loop line that connects these two parts. In the fuel pool cooling and purification system of nuclear power generation facilities,
In addition to the above-mentioned original fuel pool cooling and purification system, when all the fuel from the reactor emergency core is taken out to the fuel pool, the pool water of the fuel pool is sent to the reactor cooling and purification system and returned to the fuel pool again. The first feature is that the cooling purification back-up line is equipped with a cooling purification back-up line that allows for It also has a cooling backup line that sends the fuel to the furnace residual heat removal system and returns it to the fuel pool.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail based on an embodiment shown in FIGS. 6 to 8.

In Fig. 6, symbol A is a fuel pool cooling purification system, symbol B is a reactor cooling system (A purification system, fuel pool cooling purification system A is a fuel pool), skimmer surge tank 2, pump 3, filtration desalination. It consists of a container 4, a heat exchanger 5, a sparger 6, a closed loop line that connects each of the above parts, and various lubricants.

The reactor cooling 'A2/44 conversion system B is composed of a regenerative heat exchanger 12, a non-regenerative heat exchanger 13, a filtration demineralizer J4, and closed loop lines and various valves that connect the above parts. . 100 is the pool water feed line from the fuel pool cooling and purification system A to the reactor residual heat removal system (not shown)-8, 200d is the line from the reactor residual heat removal system to the fuel pool cooling and purification system A・＼ boule water return line, 30
0 is fuel water from fuel pool cooling purification system A to reactor cooling (pool water feed line to purification system B, 400 is reactor cooling) lA water from purification system 13 to fuel pool cooling purification system A) It shows the return line.

Here, the cooling purification mode when spent fuel that is normally scheduled to be taken out is stored in the fuel pool 1 will be explained based on FIG. 7.

The nord water in the fuel pool 1 is heated by the decay heat of the spent fuel stored in the pool 1. After the heated pool yJ It is purified by a filtration demineralizer 4 installed upstream.Pool water purified by the filtration demineralizer 4 and cooled by a heat exchanger 5 is returned to the fuel pool through a line 7. It is discharged to the bottom of the pool 1 via the snow cooler 6.

Next, the cooling purification mode when all the core fuel is stored in the fuel pool in case of a reactor emergency will be explained with reference to FIG.

Heat exchanger 5 (usually removed [
- Designed to cool the scheduled spent fuel/In case of a reactor emergency, if all the fuel removed from the core is stored in the fuel pool, the fuel pool cooling and purification system described above 80 Heat exchanger 5 excludes decay heat for each core condition! Therefore, the pool water temperature cannot be kept below the design value. For this reason, the whole core is burned out.
is removed into fuel pool 1 (line 30
0 is used to guide a portion of the pool water to the reactor cooling purification system B, thereby compensating for the lack of capacity of the heat exchanger 5. That is, in the event of a reactor emergency, since no fuel is installed in the reactor core, there is no need to cool and purify the reactor core with the reactor coolant purification system B, and in the present invention, the reactor cooling purification system J B is used as a hack-up system for the fuel MSI sol cooling and purification system A in the event of a reactor emergency. In Figure 8, when the reactor was shut down, a portion of the pool water that entered the reactor coolant purification system B via the inlet 300 is shown. It is cooled by a non-regenerative heat exchanger] 3) and purified by a filtration demineralizer 14. The non-fJf raw heat exchanger 1;
This pool water f/-j1 passes through Rain 400 to the fuel No. 1 sol cooling and purification system (returns to Pool 1. In the event of a reactor emergency, Ge-1 of Hay 1 Pool 1 is closed. If the heat load inside the node 1 after 11j is large,
It is also possible to open lines 100 and 200 and shut down the reactor residual heat removal system.

The present invention is as described above, and according to the present invention, in the event of a reactor emergency, the pool water of the fuel sol 1 is transferred to the filtration demineralizer 4 to the fuel pool cooling purification system and the reactor coolant purification system B. Purification is promoted by the filtration demineralizer 14,
The pool water purification ability can be improved compared to the previous system, which used a Banokanog system as the reactor residual heat removal system in case of an emergency.

In addition, when comparing the cooling capacities of the reactor residual heat removal system and the reactor cooling purification system, the relationship is that the reactor residual heat removal system is greater than the reactor coolant purification system; If a purification system is also installed, it is possible to select a backup system depending on whether to promote cooling or purification in the event of a reactor emergency.

Furthermore, if a reactor residual heat removal system and a reactor coolant purification system are installed together, maintenance and inspection of both systems can be performed alternately. For example, assume that the reactor residual heat removal system has been selected for the purpose of promoting cooling in the event of a reactor emergency. The reactor residual heat removal system's pumps and heat exchangers are divided into two systems, but if one of the pumps fails, the backup amplifier system of the fuel pool cooling and purification system will be replaced. By switching from the reactor residual heat removal system to the reactor coolant purification system, we can not only repair the failed pump and maintain and inspect the entire system, but also maintain and inspect the entire pump system that has not failed. - can be done at the same time.

FIG. 9 is a two-dimensional floor layout diagram of the fuel pool and its peripheral equipment located in the reactor building, and FIG. 10 is a two-dimensional floor layout diagram of the fuel pool and its peripheral equipment, which is different from FIG. 9.

In Figures 9 and 10, the symbol 1r↓fuel1''1 pool, 2 is the skimmer surge tank of the fuel pool], J5 is the fuel boule installation floor, 16 is the reactor well, 17 is the steam separator/steam drying The device bit, also in Figure 10,
18 is a sub fuel pool, 19 is a sub fuel pool 18
It shows the gap surge tank. Normally, one fuel pool is provided as shown in Figure 9, but if you want to make effective use of the building space and increase the fuel storage capacity, for example, as shown in Figure 10, a fuel pool is installed. 1
A steam/water separator that occupies less floor 15 than
A sub-combustion t1 pool 18 can be provided on the steam dryer pit 17 side.

As described above, the present invention can also be applied to a case where two fuel pools are installed.Next, the specific configuration thereof will be explained based on FIG. 11.

In FIG. 11, reference numeral 18 is a sub fuel pool attached to the fuel pool, 19 is a skimmer surge tank that overflows the pool water of the sub fuel pool 18, and 20 is a sparger installed near the bottom of the sub fuel pool 18. It shows.

Here, the cooling purification mode when spent fuel that is normally scheduled to be taken out is stored in the fuel pool 1 will be explained with reference to FIG. 12. At this time, no fuel is stored in the sub-fuel pool 18.

The pool water in the fuel pool 1 is heated by the decay heat of the spent fuel stored in the pool 1. After the heated pool water overflows into the skimmer surge tank 2, it is transported to the heat exchanger 5 by the pump 3 and cooled at the core. Note that the pool water is purified by a filter demineralizer 4 installed upstream of the heat exchanger 5. The pool water purified by the filtration demineralizer 4 and cooled by the heat exchanger 5 is returned to the fuel pool 1 through the line 7 and discharged to the bottom of the pool 1 via the sparger 6.

Next, in the event of a reactor emergency, all the core fuel is transferred to the subfuel pool 18.
The cooling purification mode in the case of storage inside the container will be explained based on FIG. 13. At this time, in the fuel pool 1,
Spent fuel that is normally scheduled for removal is stored.

In FIG. 13, the fuel sol 1 and the sub fuel pool 18
are completely separated through valves 30, 40 and 50, and the sol water C in the fuel pool J is cooled and purified by the fuel pool cooling and purification system A. In addition, the pool water 'rJ' of the sub-fuel pool 18 is cooled and purified by the reactor residual heat removal system (not shown) and the reactor cooling system B. The reactor residual heat removal system alone is sufficient to cool the pool water in the Zabumu T1 pool 18, but since the reactor residual heat removal system is not equipped with a filtration demineralizer, reactor coolant purification is required. The pool water of the sub fuel pool 18 is purified using the filtration demineralizer 14 of system B.

Below, the case of cooling and purifying the pool water of fuel pool 1,
The case of cooling and purifying the pool water of the sub fuel pool 18 will be explained separately.

(When purifying the pool water of the fuel pool J by cooling it) The pool water of the fuel pool 1 is heated by the decay heat of the spent fuel stored in the pool 1. After the heated pool water overflows into the skimmer surge tank 2, it is transported to the heat exchanger 5 by the pump 3 and cooled at the core. Note that the pool water is purified by a filter demineralizer 4 installed upstream of the heat exchanger 5. The pool water purified by the filtration demineralizer 4 and cooled by the heat exchanger 5 is returned to the fuel pool 1 through the entire line 7, and is discharged to the bottom of the pool 1 via the sparger 6.

(When pool water in the sub fuel pool 18 is cooled and purified) In a reactor emergency, the pool water in the sub fuel pool 18 is heated by the decay heat of the fuel taken out from the core. After the heated pool water flows into the skimmer surge tank 19, it is conveyed via lines 100 and 300 to the reactor residual heat removal system (not shown) and the reactor cooling port purification system B, where it is removed from the reactor residual heat. It is cooled by the heat exchanger of the removal system and the non-regenerative heat exchanger 13 of the reactor coolant purification system B. At this time, the pool water in the sub-fuel pool 18 is purified by the filtration demineralizer 14 of the reactor coolant purification system B. The pool water cooled by the heat exchanger of the reactor residual heat removal system passes through the line 200 to the sub-fuel pool 18.
is returned to the sub-fuel pool 18 via the sparger 20.
is discharged at the bottom of the tank. On the other hand, the pool water cooled by the non-regenerative heat exchanger 13 of the reactor cooling port purification system B and purified by the filtration demineralizer 14 passes through the line 400 to the sub-fuel pool 18.
is returned to the subfuel pool 18 via the sparger 20.
is discharged at the bottom of the tank. In the above embodiment, cooling of the pool water in the sub-fuel pool 18 is performed by the reactor residual heat removal system (
Although the case where the heat exchanger (not shown) and the non-regenerative heat exchanger 13 of the reactor coolant purification system B are used as an example, the cooling capacities of the reactor residual heat removal system and the reactor coolant purification system are compared. , reactor residual heat removal system> Since it is related to the reactor cooling port purification system, if the purpose is to accelerate cooling of the pool water in the sub-fuel pool 18 in a reactor emergency, the reactor coolant purification system It is also possible to suspend operation of B and operate only the reactor residual heat removal system.

On the other hand, if the main purpose is to purify the pool water in the sub fuel pool 18, the operation of the reactor residual heat removal system may be suspended and only the reactor coolant purification system B is operated. can.

In addition, in FIG. 11, when the fuel storage capacity of fuel pool 1 is large, in other words, the fuel storage capacity of fuel pool 1>the bulk of the total amount of spent fuel to be normally removed from the reactor emergency core If this is the case, either the spent fuel that is normally scheduled to be removed is stored in the fuel pool 1, and all the fuel that is to be removed from the reactor emergency core is stored with a large margin in the sub-fuel pool 18, or the spent fuel that is normally scheduled to be removed is stored in the sub-fuel pool 18 with a large margin. The fuel and all the fuel removed from the reactor emergency core are stored in fuel pool 1.
The cooling purification mode in the former case can be replaced by the cooling purification mode shown in FIGS. 12 and 13, and the cooling purification mode in the latter case can be explained as follows. The explanation can be replaced by the cooling purification mode shown in FIGS. 7 and 8.

〔Effect of the invention〕

As detailed above, according to the present invention, in the event of a nuclear reactor emergency,
It is possible to obtain an upgraded fuel pool cooling and purification system that has not only the ability to cool fuel pool water but also the ability to purify it, and the present invention has the following features:
It can be applied not only when there is one fuel pool but also when there are two fuel pools.

[Brief explanation of the drawing]

Figure 1 is an overall system diagram showing a conventional example of a fuel pool cooling and purification system, Figures 2 and 3 are mode explanatory diagrams of the cooling and purification system shown in Figure 1, and Figure 4 is a diagram showing reactor residual heat. FIG. 5 is an overall system diagram of the removal system, and FIG. 5 is a mode explanatory diagram of the residual heat removal system shown in FIG. Figures 7 and 8 are mode explanatory diagrams of the cooling and purification system shown in Figure 6, Figure 9 is a planar floor layout diagram of the fuel pool and its peripheral equipment located in the reactor building, and Figure 10 is a diagram showing the mode of the cooling and purification system shown in Figure 6. Fig. 11 is a plan view of the fuel pool and its peripheral equipment, which is different from Fig. 9, and Fig. 11 is another embodiment of the present invention. Fig. 12 is an overall system diagram of the fuel pool cooling and purification system. Figure 13 is the first
2 is a mode explanatory diagram of the cooling purification system shown in FIG. 1. FIG. A... Fuel pool cooling purification system, B... Reactor coolant purification system, 1... Fuel pool, 2... Skimmer surge tank, 3... Pump, 4... Filtration demineralizer , 5...
Heat exchanger, 6... Sparger, 7... Line, 8.
...Pump, 9...Heat exchanger, 10 and 11...
Line, 12... Regenerative heat exchanger, 13... Non-regenerative heat exchanger, 14... Filtration demineralizer, 15... Fuel pool installation floor, 16... Reactor well, 17...・Steam water separator ・Steam dryer pit, 18...Sub fuel punope 19...Skimmer surge tank, 20...Sparger, 30.40 and 50...Valve, 100,2
00, 300 and 400... lines. Figure 7 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A fuel pool, a skimmer surge tank, a pump,
In the fuel pool cooling and purification system of a nuclear power generation facility, which is equipped with a heat exchanger, a filtration demineralizer, and a closed loop line that connects the above-mentioned parts, in addition to the above-mentioned original fuel pool cooling and purification system, the reactor emergency core is characterized by being equipped with a cooling purification back-up in which, when all the fuel in the nuclear fuel pool is taken out to the fuel pool, the pool water of the nuclear fuel pool is sent to the reactor coolant purification system and returned to the fuel pool again. Fuel pool cooling purification system. 2 Fuel pool, skimmer surge tank, pump,
In the fuel pool cooling and purification system of a nuclear power generation facility, which is equipped with a heat exchanger, a filtration demineralizer, and a closed loop line that connects each part, in addition to the above-mentioned original fuel pool cooling and purification system, there is also a reactor emergency When all the fuel from the reactor core is removed to the fuel sol, there is a cooling purification backup line that sends the pool water of the fuel pool to the reactor coolant purification system and returns to the fuel pool again, and a cooling purification backup line that sends the pool water of the fuel pool to the reactor coolant purification system and returns it to the fuel pool. A fuel a+r+pool cooling and purification system is characterized in that it is equipped with a cooling backup line that sends the fuel to the reactor residual heat removal system and returns it to the fuel pool.