JPS59218993A - Bwr type reactor - 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] 1. Technical Field of the Invention] The present invention relates to a boiling water nuclear reactor, and particularly to a boiling water reactor equipped with a purification device for purifying water in a pressure suppression chamber housed in a pressure suppression chamber. About watercolor nuclear reactors.

[Technical review of the invention 1 and its problems] In general, in a boiling water reactor, steam from the IJI reactor 1r power vessel that houses the reactor core is released and introduced through a safety valve.
A pressure suppressor B111 is provided to condense this steam.

'71 In other words, this pressure suppression chamber condenses the steam introduced through the relief safety valve in order to alleviate the pressure rise in the reactor in the event of an accident in a boiling water reactor, and also condenses the steam contained in the steam. It has the function of dissolving various nuclear fission products in the pressure suppression chamber water and preventing the spread of radioactive materials. In particular, the gas-liquid partition coefficient of iodine, which is a fission product C, among the functions required of the pressure suppression chamber water in iJ3 at the time of an accident, has important implications for safety evaluation in various accidents, etc. The ratio of iodine is defined as the gas-liquid partition coefficient, which can be expressed by the following equation.

Gas-liquid partition coefficient - Iodine m in the liquid phase/Iodine amount in the gas phase It is generally known that the gas-liquid partition coefficient of iodine is greatly influenced by the characteristics of the liquid, and is shown in Figure 1. It has the characteristics shown below.

In Figure 1 (the horizontal axis is pl-1, the vertical axis is 21
As shown by straight line a in the figure, it can be seen that, for example, at point M, where the pH is higher than point L in the figure, the gas-liquid partition coefficient of iodine increases exponentially.

In the event of an accident, it is important to maintain a high gas-liquid partition coefficient of iodine in the pressure suppression city C and keep the separation of iodine into the gas phase as low as possible. There are things that are extremely important, and for that purpose I must always use Jf.
The right column is to maintain the force suppression chamber water p]-1 alkaline or weakly acidic η-.

C In a conventional boiling water reactor, the suppression chamber water C
I] Although F2 salt water is used, there are no facilities or devices in place to maintain water quality, and no water purification is performed.

However, it is known that the quality of the water in the pressure suppression chamber gradually changes due to the operation of the core cooling system Bonzo, which is carried out at a constant lft, or the dissolution of impurities from the gas phase. There is a need for a boiling water reactor that can maintain pressure suppression chamber water at a slightly acidic level.

[Objective of the Invention 1 The present invention has been made in response to such conventional circumstances.
Keeps pressure suppression chamber water alkaline or weakly acidic.
There are efforts to provide a boiling water reactor equipped with a purification system capable of reducing the amount of water used.

[Summary of the Invention 1 Zunawara Honzatomei has a pressure suppression chamber that releases steam from a reactor pressure vessel housing a reactor core, introduces it through a safety valve, and condenses the steam, and a pressure suppression chamber that condenses the steam. There is a boiling water nuclear reactor C which is characterized by being equipped with a purification device that maintains the contained pressure suppression chamber water to be alkaline or weakly acidic.

[Embodiment of the Invention] An embodiment of the present invention detailed in the drawings will be described below.

Figure 2 shows a boiling water reactor according to an embodiment of the present invention. lb
Therefore, in the figure, the reference numeral 1 indicates the reactor pressure vessel that houses the reactor core 2. This reactor pressure vessel 1 is housed in a reactor containment vessel 3, and a pressure suppression chamber 5 is arranged in Th of this reactor containment vessel 3, which communicates with the inside of the reactor containment vessel 3 through a connecting pipe 4. It has been t9. A main steam pipe 6 connected to a turbine (not shown) is installed in the upper part of the reactor pressure vessel 1, and a main steam recess 1 valve 7a, a main steam recess 1 valve 7a, and a reactor containment vessel 3 are sandwiched between the main steam pipe 6 and a turbine (not shown). 7b or C is placed. A relief safety valve 8 is provided upstream of the main steam isolation valve 7a, and an IC exhaust pipe 9 is branched, and the trachea 9 opens into the pressure suppression chamber water of the pressure suppression chamber 5. A core cooling system injection pipe 10 connected to the pressure suppressor 5 opens at the top of the reactor pressure vessel 1, and an injection valve 11 is connected to the core cooling fJI system injection pipe 10 in order from the reactor pressure vessel 1 side.
A core cooling system pump 12 is inserted. Soshi-
A core cooling system dest pipe 14a is provided, which branches out between the injection valve 11 of the C core cooling 1.11 system injection pipe 10 and the core cooling yield system pump 12 and is equipped with a test pipe valve 13 that connects to the pressure suppression chamber 5. 8reC is there. Core cooling IJ system injection arrangement? 't 10's core cooling uI system bonno 12 branched from the exit aide 1 and connected to i J convex '14
11S with 1 salt tower inlet valve 15 (salt tower entry [] arrangement 1
6 is installed and desalination is performed. For '+1/l, connect the 1;1 salt tower outlet valve 17, which is connected to the inlet side of the core cooling 7i11 system 6-man piping 10, to the inlet side of the core cooling J [system Bon-] 12. , 1. [I piping 18 is connected.

1. As shown in S1 (111), the main steam isolation valves 7a and 7b of the boiling water reactor C were fully opened at the time of the accident, and the pressure in the reactor 1 increased abnormally. in case of,
The relief safety valve 8 disposed inside the reactor containment vessel 3 is activated, and the steam inside the reactor pressure vessel 1 is guided into the pressure suppression chamber 5 through the exhaust pipe 9 and condensed, and as a result, the reactor 1. As the pressure inside the L-capacitor 1 decreases, nuclear fission products such as radioactive iodine are dissolved in the pressure suppression chamber water.

And C, the boiling water reactor C configured as above is
Maintaining the alkalinity or weak IF of the pressure suppression air water is carried out by the periodic reveiler of the core cooling IJl system pump 12>), (SUR
Vf: I1-LANCfE) 31 turn 11 is performed as follows.

In other words, during such a thermal injection operation, the injection 1711 installed in the core cooling system injection pipe 1o is fully opened, the test pipe valve 13 is fully opened, and the core cooling system test pipe FT 14a is used to Core cooling system pump 12
By reactor core? '4 f Pressure suppressing air water is circulated within the JI system Ejin piping 10.

Then C1 In this case, fII2 j9 j input valve 15
and Dl, i1; l'A J output 11 valves 17, IBJ I product IQ input 11 piping 16d5 and 1111
! Using the pipe 18 of "Hanawa Tower Outlet 1", the power of the CII Tower 14 (1F) can be suppressed by passing water through it.
Water is treated 1j11 times. Special) This IIf21 product tower 14
(The 11 force-inhibited 4g water loaded with only the anion A and the sulfuric resin and subjected to water flow treatment in the I5 state becomes noflukaline, and +13). It will be as follows.

As an example, if you go back and forth over the polymer part of the ion exchange resin, the 1tz ion exchange resin will be R・NO.
Ionic impurities in the pressure suppression chamber water are expressed as +-1,
For example, in the case of NaCρ, R-N0II+Na
C,g→RN-CI! , an ion exchange reaction of iNa 0f-1 occurs, and the process J! 1! ml of water becomes alkaline.

94L: In the boiling water reactor C configured as described above, a portion of the suppression chamber water is desalinated from the outlet side of the core cooling system pump 12. 'J14 DID salt treatment makes it easy to maintain the pH of the pressure suppression chamber water at an alkaline or slightly acidic level. The distribution coefficient can be sufficiently increased.Also, in the desalination tower 14, positive and negative A > mixed tree 1
Load the finger and treat the I'f force suppression and hydrous water C'
It is now possible to desalinate water in the liquid suppression chamber, making it possible to use repulsion suppression chamber water! 1. Is it possible to maintain corrosion and suppress the corrosion in the Song Dynasty?

δ et al. 11 force suppression air water/1 Removal of radioactive materials also iiJ
Noise, pressure suppression chamber 5 and core cooling IJI system pump 1
2. The effect of reducing the copper wire m rate of related piping is also 1! '7 is possible.

(Effects of the Invention) As described below, in the single-flow water reactor of the present invention, a portion of the pressure suppression chamber water can be used to cool the reactor core, for example.
During no-payance operation, it is possible to make the pressure suppression chamber water alkaline or weakly acidic by treating it with salt, and as a result, in the event of an accident, the iodine gas and liquid It is important to maintain the distribution coefficient sufficiently on the safe side.
), and at the same time, it is possible to maintain the quality of the water in the repulsion suppression chamber and reduce the radioactivity concentration.

[Brief explanation of drawings]

Fig. 1 is a graph showing the relationship between 11 + - 1 and the gas-liquid partition coefficient, and Fig. 2 is a graph showing the relationship between 11 + - 1 and the gas-liquid partition coefficient, and Fig. 2 is one example of the present invention. There is a piping system diagram C for the boiling water reactor in Example I. 1......Reactor pressure vessel 3...
・・・・・・Reactor containment vessel 5・・・・・・・・・
...Ll-Force suppression palm 6...Main steam piping 8...Relief safety valve 10...
......Core cooling uI system injection pipe 12...
......Core cooling system pump 14...
・・・・・・Demineralization tower 1/la・・・・・・・・・Core cooling 2J] Piping to system 16・・・・・・・・・・・・n; (Tower artificial piping 1
B・・・・・・・・・Desalination tower outlet piping agent Patent attorney Suyama I11- Figure 1 5.0 5.5 6.0 6.5
7. OI-1

Claims (1)

[Claims] (1) A pressure suppression chamber that releases steam from the reactor pressure vessel that houses the reactor core and introduces it through a safety valve to avoid condensation, and the pressure suppression chamber water contained in this pressure suppression chamber is made alkaline or weakly acidic. A boiling water type 1 (child furnace) characterized by being equipped with a purification device to maintain the boiling water temperature.