JP7418300B2 - Iodine behavior confirmation device, iodine behavior confirmation system, and iodine behavior confirmation method - Google Patents

Description

The present disclosure relates to an iodine behavior confirmation device, an iodine behavior confirmation system, and an iodine behavior confirmation method that recover iodine by irradiating a solution in which iodine is dissolved with radiation.

Pool water (hereinafter referred to as pool water) in a spent fuel pool (hereinafter referred to as SFP; Spent Fuel Pool) in which spent fuel is stored may contain iodine. When pool water is irradiated with gamma rays, some of the iodine in the pool water may react and be released as gaseous iodine molecules I ₂ (gas).

Patent Document 1 describes a main system activated carbon adsorption cylinder provided in a flow path of a processing fluid containing iodine, a bypass line adsorption cylinder provided in parallel with the main system activated carbon adsorption cylinder, and a main system activated carbon adsorption cylinder and a bypass line adsorption cylinder. A main system inlet sampling device connected to the inlet side piping of the main system activated carbon adsorption column, a main system outlet sampling device connected to the outlet side piping of the main system activated carbon adsorption cylinder, and a bypass line adsorption system connected to the outlet side piping of the bypass line adsorption cylinder. In the iodine adsorption/removal efficiency confirmation test device that has a sampling device on the outlet side of the cylinder, the iodine adsorption/removal efficiency of the activated carbon adsorption cylinder when the processing flow rate is suddenly changed is determined by the radioactive concentration of iodine in each sampling device. It is described that it can be determined by the ratio of .

Utility Model Publication No. 2-014095

It is required to appropriately evaluate gaseous iodine released from pool water in which iodine in SFP is irradiated with gamma rays.

The present disclosure has been made in view of such problems, and aims to provide an iodine behavior confirmation device, an iodine behavior confirmation system, and an iodine behavior confirmation method for appropriately evaluating iodine.

An iodine behavior confirmation device for solving the above problems includes a container containing a solution in which iodine is dissolved, a radiation source that irradiates the solution in the container with radiation, and iodine released from the solution by irradiation from the radiation source. The device includes a connecting pipe through which the gaseous iodine flows, and a collection section connected to the connecting pipe to collect the iodine.

An iodine behavior confirmation system for solving the above problem includes the iodine behavior confirmation device and a measuring device that measures iodine collected by the iodine behavior confirmation device.

A method for confirming iodine behavior to solve the above problem includes using the iodine behavior confirmation device to irradiate the solution in the container with radiation from the radiation source to remove gaseous gas from the container in the container. a step of releasing iodine; a step of reducing irradiation of the radiation to the solution in the container to a predetermined threshold value or less for a predetermined time; and collecting the iodine released from the solution in the collection unit. and a step.

FIG. 1 is a schematic diagram showing an iodine behavior confirmation system according to this embodiment. FIG. 2 is a block diagram of the measuring device according to this embodiment. FIG. 3 is a flowchart showing the iodine behavior confirmation method according to this embodiment. FIG. 4 is a schematic diagram showing the behavior of iodine in the SFP according to the present disclosure.

An embodiment of the iodine behavior confirmation system 10 according to the present disclosure will be described below using FIGS. 1 to 3. FIG. 1 is a schematic diagram showing an iodine behavior confirmation system according to this embodiment. FIG. 2 is a block diagram of the measuring device according to this embodiment. FIG. 3 is a flowchart showing the iodine behavior confirmation method according to this embodiment. Note that what is described in this disclosure is one embodiment of the present invention, and the present invention is not limited thereby.

<Iodine behavior confirmation system>
The iodine behavior confirmation system 10 according to the present disclosure includes an iodine behavior confirmation device 20 and a measuring device 30, as shown in FIG. The measuring device 30 may be installed in a different space from the iodine behavior confirmation device 20. Further, the iodine behavior confirmation device 20 and the measuring device 30 may be configured as one unit.

<Iodine behavior confirmation device>
The iodine behavior confirmation device 20 collects gaseous iodine released from the solution M in the container 150 when irradiated with radiation from the radiation source 100 . As shown in FIG. 1, the iodine behavior confirmation device 20 includes a radiation source 100, a gas recovery section 110, a drive section 120, a control section 130, and an inert gas supply section 140. The radiation source 100 can be moved relative to the gas recovery section 110 by a drive section 120. The iodine behavior confirmation device 20 may also include a display section and an output section (not shown).

<Radiation source>
The radiation source 100 irradiates the solution M in the container 150 with radiation. The radiation emitted from the radiation source 100 is, for example, a gamma ray having a wavelength shorter than 10 pm. In the following description, the radiation emitted from the radiation source 100 will be explained as gamma rays. Note that the radiation source 100 may irradiate the gas recovery section 110 including the container 150, the radiation source 100, the connecting pipe 160, and the collection section 170 with gamma rays.

<Gas recovery department>
The gas recovery unit 110 recovers iodine released from the container 150. The gas recovery section 110 includes a container 150, a connecting pipe 160, a check valve 162, a temperature adjustment section 152, a pH meter 154, and a collection section 170, as shown in FIG.

<Container>
Container 150 stores solution M. Container 150 stores a predetermined volume of solution M. The container 150 has a connection port connected to the connecting pipe 160 on the top surface. Container 150 is made of a material that transmits gamma rays. Further, the container 150 is made of a corrosion-resistant material. The portion of the container 150 that comes into contact with iodine is made of a glass-based material. Container 150 may be made of a glass-based material.

In solution M, iodine is dissolved in water (H ₂ O). Iodine dissolves in water mainly in the form of iodine ion I ^- . When the solution M is irradiated with gamma rays, some of the iodine ions I ^- react to form gaseous iodine molecules I ₂ (gas). A portion of the gaseous iodine molecules I ₂ (gas) is released from the solution M. As solution M, pool water in the actual SFP is used. Further, the solution M may be a solution generated by simulating the boron concentration, acidity, etc. of pool water.

<Connecting pipe>
Connecting pipe 160 connects container 150 and collection section 170. Specifically, as shown in FIG. 1, the connecting pipe 160 has one end connected to the container 150 and the other end connected to the collection section 170. Gas and liquid can flow through the connecting pipe 160. The connecting pipe 160 has a check valve 162. The connecting pipe 160 has, for example, a curved shape such that one end and the other end face in the same direction. Further, the connecting pipe 160 is made of a corrosion-resistant material. The portion of the connecting tube 160 that comes into contact with iodine is made of a glass-based material. The connecting pipe 160 may be made of a glass-based material.

<Check valve>
The check valve 162 closes off fluid flowing through the connecting pipe 160 from the collecting section 170 toward the container 150 . Furthermore, the check valve 162 allows fluid at a predetermined pressure (cracking pressure) or higher to flow from the container 150 toward the collecting section 170 . Here, the cracking pressure of the check valve 162 is sufficiently greater than the pressure of gaseous iodine released from the solution M. The check valve 162 is installed in the connecting pipe 160 between the container 150 and the collecting section 170, as shown in FIG. More desirably, the check valve 162 is installed at a portion where the container 150 and the connecting pipe 160 are connected. A portion of the check valve 162 that comes into contact with iodine is made of, for example, a glass-based material. Note that the check valve 162 may be constituted by a normal on-off valve. In this case, by operating the valve (162), switching is performed between an open state in which fluid can flow through the inside of the connecting pipe 160 and a closed state in which fluid can not flow through the inside of the connecting pipe 160.

<Collection section>
The collection unit 170 collects iodine released from the solution M in the container 150. The collection section 170 is connected to the other end of the connecting pipe 160. The collection section 170 is made of a material that is corrosion resistant. The portion of the collection unit 170 that comes into contact with iodine is made of a glass-based material. The collection section 170 may be made of a glass-based material.

The collection unit 170 collects gaseous iodine discharged from the other end of the connecting pipe 160. Gaseous iodine is collected by a so-called liquid collection method in which it is reacted with a collection liquid W. The collection liquid W is a strongly basic solution. The collection liquid W is preferably a potassium hydroxide solution KOH (aq). In addition, as the collection liquid W, a solution that can collect iodine and suppress release of the collected iodine into the gas phase even in an environment where gamma rays are irradiated can be used. Note that the method of collecting iodine by the collecting section 170 is not limited to the liquid collection method. The iodine collection method by the collection unit 170 may be, for example, a solid collection method.

The collection unit 170 can have a configuration as shown in FIG. 1, for example. According to FIG. 1, the collection section 170 includes a first collection section 170A, a second collection section 170B, a ventilation pipe 170C, and an exhaust pipe 170D. The first collecting section 170A collects the liquid component flowing through the connecting pipe 160 together with gaseous iodine. The second collecting section 170B collects gaseous iodine. Potassium hydroxide solution KOH (aq), which is the collection liquid W, is stored inside the second collection section 170B. The first collecting section 170A and the second collecting section 170B are, for example, beakers having an opening on the top surface, and the opening is closed with a cap. Further, the ventilation pipe 170C and the exhaust pipe 170D are glass pipes. The first collection section 170A is connected to the connecting pipe 160. Specifically, the connecting tube 160 is inserted through the cap of the first collecting section 170A, and the other end of the connecting tube 160 is arranged inside the first collecting section 170A. The ventilation pipe 170C connects the first collection section 170A and the second collection section 170B. Specifically, one end of the ventilation pipe 170C is placed inside the first collection section 170A, and after passing through the cap of the first collection section 170A and coming out, it is inserted into the second collection section 170B. The cap is inserted, and the other end of the vent pipe 170C is placed near the water surface of the collected liquid W in the second collecting section 170B. The exhaust pipe 170D allows the inert gas and the like in the second collection section 170B to flow out of the second collection section 170B.

<Temperature adjustment section>
The temperature adjustment unit 152 adjusts the solution M in the container 150 to a predetermined temperature. The temperature adjustment unit 152 includes a thermometer 152A that measures the temperature of the solution M, and a heater 152B that heats the solution M, as shown in FIG. The heater 152B heats the solution M according to the measurement result of the thermometer 152A. The heater 152B is configured by, for example, a mantle heater, and is used by being wrapped around the outer periphery of the container 150.

<pH measuring device>
The pH meter 154 measures the acidity of the solution M in the container 150. The pH measuring device 154 measures the iodine ion concentration contained in the solution M by measuring the acidity of the solution M in the container 150.

<Drive section>
The drive unit 120 moves the radiation source 100 relative to the container 150. The direction in which the drive unit 120 relatively moves the radiation source 100 is, as shown in FIG. 1, a horizontal direction, but is not limited thereto and may be a vertical direction. The drive unit 120 can arbitrarily set the distance D between the radiation source 100 and the container 150. Further, the drive unit 120 can adjust the speed of relative movement. The drive section 120 is driven based on instructions from the control section 130. The drive unit 120 is configured by, for example, a motor drive. Note that the drive unit 120 may be configured such that the gas recovery unit 110 moves relative to the radiation source 100.

The driving unit 120 moves the radiation source 100 relative to the container 150, thereby switching between a first state in which a predetermined dose of gamma rays is irradiated from the radiation source 100 to the container 150, and a state in which the container 150 is irradiated with gamma rays from the radiation source 100. and a second state in which a low dose is irradiated. In the first state, the solution M in the container 150 is irradiated with gamma rays at a predetermined dose γ1 from the radiation source 100 at a separation distance D1. The predetermined dose in the first state may be arbitrarily set, and may be determined based on, for example, the dose irradiated from the spent fuel stored in the actual SFP that is the simulation target. In the second state, the solution M in the container 150 is irradiated with gamma rays from the radiation source 100 at a dose γ2 lower than in the first state at a separation distance D2. For example, the dose γ2 of gamma rays with which the solution M is irradiated in the second state is equal to or less than γ2=(separation distance D1/separation distance D2) ² ·γ1. Here, the separation distance between the radiation source 100 and the container 150 is the separation distance D1<the separation distance D2, and the dose γ2 of gamma rays with which the solution M in the second state is irradiated is the same as that of the solution M in the first state. It is lower than the dose γ1 of gamma rays to be irradiated. The predetermined dose γ2 in the second state may be arbitrarily set, and may be determined, for example, by the dose irradiated from the spent fuel stored in the actual SFP that is the simulation target and the water level of the pool water. It's fine.

<Control unit>
The control section 130 controls the drive section 120. The control unit 130 controls the drive unit 120 to maintain a predetermined separation distance D and a predetermined moving speed. The control unit 130 may control the drive unit 120 according to a preset movement pattern.

<Inert gas supply section>
The inert gas supply unit 140 supplies an inert gas to purge the inside of the connecting pipe 160. The inert gas supply section 140 is connected to the container 150 side of the connecting pipe 160. Specifically, the inert gas supply unit 140 is connected between one end of the connecting pipe 160 connected to the container 150 and the check valve 162. The inert gas supply section 140 may be connected to the connecting pipe 160 via a check valve or the like. The inert gas supply section 140 has a main valve 142, and supplies inert gas by operating the main valve 142. Further, the inert gas supply unit 140 has a pressure reducing valve (not shown), and inert gas adjusted to a predetermined pressure by the pressure reducing valve is supplied. The supply pressure of the inert gas from the inert gas supply section 140 is preferably higher than the cracking pressure of the check valve 162. The inert gas used in the inert gas supply section 140 is, for example, nitrogen gas. Note that the inert gas is not limited to nitrogen gas.

<Measuring device>
The measuring device 30 measures the iodine collected by the iodine behavior confirmation device 20. As shown in FIG. 2, the measuring device 30 includes a measuring section 180, a control section 182, a display section 184, an output section 186, and a recording section 188. Note that the measuring device 30 may be configured as a part of the iodine behavior confirmation device 20.

The measurement unit 180 measures iodine contained in the collection liquid W. The measurement unit 180 measures the concentration of the collection liquid W containing iodine collected by the collection unit 170 using an electrode method. The collection liquid W can collect iodine contained in the solution M. In this case, the measurement unit 180 measures the potential difference of iodine contained in the collection liquid W collected by the collection unit 170 using, for example, an iodide ion electrode, and calculates the concentration. Note that the measurement of iodine in the measurement unit 180 is not limited to the electrode method, and may be performed using any method. The measurement results in the measurement section 180 are recorded in the recording section 188 by the control section 182. Furthermore, the measuring device 30 may display the measurement results on the display section 184 or output them to the output section 186.

The control unit 182 controls the entire measuring device 30. The control section 182 is connected to the measurement section 180, the display section 184, the output section 186, and the recording section 188. The control unit 182 is, for example, a CPU (Central Processing Unit).

The display unit 184 displays information on the screen. The display unit 184 displays various information acquired by the control unit 182 in the form of, for example, a time series graph. The display unit 184 is, for example, a monitor.

The output unit 186 outputs the information acquired by the control unit 182. The output unit 186 is, for example, a printer.

The recording unit 188 records data and programs. The recording unit 188 records the information acquired by the control unit 182, for example, as data for each time series. The recording unit 188 is an HDD (Hard Disk Drive) or the like. Further, the recording unit 188 may be a portable recording medium.

<How to check iodine behavior>
The method for confirming iodine behavior according to this embodiment will be described below with reference to FIGS. 1 to 3. The iodine behavior confirmation method is performed using the iodine behavior confirmation system 10. Note that, in the iodine behavior confirmation method, steps S10 to S16 are performed using the iodine behavior confirmation device 20, and S18 is an iodine behavior confirmation method performed using the measuring device 30. The iodine behavior confirmation method described below is explained as a continuous iodine behavior confirmation method for convenience, but the iodine behavior confirmation method related to S10 to S16 and the iodine behavior confirmation method related to S18 are independent iodine behavior confirmation methods. It can be implemented as a behavior confirmation method. Each step will be explained below.

In S10, the control unit 130 causes the radiation source 100 to irradiate the solution M in which iodine is dissolved in the container 150 with gamma rays for a predetermined period of time. S10 is the first state. In S10, the solution M is placed at a predetermined distance D1 from the radiation source 100. The solution M is adjusted to a predetermined temperature by the temperature adjustment section 152. The acidity of the solution M is obtained by the pH measuring device 154. Furthermore, inert gas is not being supplied from the inert gas supply section 140, and the check valve 162 of the connecting pipe 160 is in a closed state. By being irradiated with gamma rays, some of the iodine ions I ⁻ of the solution M in the container 150 react, and are released from the solution M as gaseous iodine molecules I ₂ (gas). Here, liquid components such as water vapor are also released from the solution M along with gaseous iodine molecules I ₂ (gas). The liquid component may include droplets of solution M that scatter from the container 150 when the inert gas is purged.

Gaseous iodine molecules I ₂ (gas) released from the solution M by irradiation with gamma rays from the radiation source 100 move between the container 150 and the connecting pipe 160 under the first condition in which a predetermined dose of gamma rays is irradiated. It exists between the check valve 162 (160A).

In S12, the solution M is cured for a predetermined period of time in a state in which the dose of gamma rays irradiated is equal to or less than a predetermined threshold value (the above-mentioned "second state"). Specifically, by relatively moving the radiation source 100 in a direction away from the container 150 to set the separation distance D2, the first state is changed to the second state, and the second state is maintained for a predetermined period of time. Here, the relative movement of the radiation source 100 is performed by the drive section 120. Further, the water surface of the container 150 and the check valve 162 of the connecting pipe 160 are in a closed state. That is, gaseous iodine released from the solution M exists between the water surface of the solution M in the container 150 and the check valve 162 (160A). The gaseous iodine molecules I ₂ (gas) existing between the container 150 and the check valve 162 of the connecting pipe 160 (160A) are in an equilibrium state under the second state. That is, in the second state, a part of the gaseous iodine molecules I ₂ (gas) released from the solution M is dissolved or redissolved in the solution M to become iodine ions I ⁻ .

Note that in this embodiment, the dose of gamma rays irradiated to the solution M in the container 150 is changed by changing the separation distance D, but the dose of gamma rays irradiated to the solution M in the container 150 is not limited to this. good. Furthermore, the dose of gamma rays irradiated from the radiation source 100 to the solution M can be kept below a predetermined threshold by, for example, installing a lead plate between the radiation source 100 and the container 150 to shield gamma rays. It's okay to be hurt. Everything after S12 is performed in the second state.

In S<b>14 , the control unit 130 opens the main valve 142 of the inert gas supply unit 140 to flow inert gas at a pressure higher than the predetermined cracking pressure inside the connecting pipe 160 , and closes the check valve 162 . leave it open. As a result, gaseous iodine moves from between the water surface of the solution M and the check valve 162 of the connecting pipe 160 (160A) to between the check valve 162 of the connecting pipe 160 and the collection part 170 (160B). It is distributed and sent to the collection section 170. Here, the liquid component released from the solution M along with the gaseous iodine is also sent to the collection section 170. Note that when the check valve 162 is replaced by a normal on-off valve, the valve (162) may be opened after the main valve 142 of the inert gas supply section 140 is opened.

In S16, the collection unit 170 collects iodine. Specifically, in the first collecting part 170A, the collecting part 170 collects the liquid component sent together with the gaseous iodine discharged from the connecting pipe 160, and then in the second collecting part 170B. , collects the iodine sent from the first collecting section 170A. The second collection unit 170B collects gaseous iodine using a liquid collection method. That is, the gaseous iodine sent to the second collection section 170B reacts with the potassium hydroxide solution, which is the collection liquid W, and is collected. The inert gas supplied from the inert gas supply unit 140 does not react with the collection liquid W and is exhausted from the exhaust pipe 170D.

The reaction formulas between gaseous iodine and potassium hydroxide solution are shown in formulas 1 and 2 below.
I ₂ (gas) + KOH (aq) → KIO ₃ + KI + H ₂ O... (Formula 1)
KI (aq) + I ₂ (gas) → I ₃ ^- +K ⁺ ... (Formula 2)
Equation 1 shows that gaseous iodine molecules I ₂ (gas) react with potassium hydroxide solution KOH (aq) to form potassium iodate KIO ₃ and potassium iodide KI. Equation 2 also shows that gaseous iodine molecule I ₂ (gas) becomes triiodide ion I ₃ ⁻ by reaction with potassium iodide solution KI (aq).

In S18, the measuring device 30 measures iodine in the collection liquid W collected by the collection unit 170. The measurement of iodine is performed by the measurement unit 180, for example, by measuring the potential difference of iodide ions (I ₃ ⁻ ) in the collection liquid W using an electrode method and calculating the concentration. The measurement results are recorded in the recording unit 188, for example.

<Status of iodine in SFP>
Below, changes in the state of iodine within the SFP (corresponding to the container 150) will be explained with reference to FIG. 4. As shown in FIG. 4, pool water (corresponding to solution M) in which iodine is dissolved is stored in SFP 150 in which spent fuel (corresponding to radiation source 100) is placed at the bottom. Here, the region 150A at the bottom of the SFP where the spent fuel is placed is irradiated with a high dose of gamma rays γ1 from the spent fuel 100. Furthermore, the region 150B on the water surface side of the SFP is irradiated with gamma rays γ2 at a dose that decreases in inverse proportion to the square of the distance from the spent fuel 100.

As described above, in the iodine in the pool water M, iodine ions I ⁻ , gaseous iodine molecules I ₂ (gas), and iodine molecules I ₂ (aq) dissolved in the pool water exist in an equilibrium state. The equilibrium state of iodine is determined by the dose of gamma rays irradiated from the spent fuel 100, the temperature, pressure, acidity, etc. of the pool water. That is, the equilibrium state of iodine in the pool water M1 in the region 150A at the bottom of the SFP is different from the equilibrium state of iodine in the pool water M2 in the region 150B on the SFP water surface side. Iodine ions I ⁻ dissolved in the pool water M1 in the area 150A at the bottom of the SFP partially react with the irradiation with high doses of gamma rays from the spent fuel, and become gaseous iodine molecules I ₂ (gas). becomes.

The region 150A at the bottom of the SFP is close to the spent fuel 100 and is a region where the dose of gamma rays irradiated is high. Here, the pool water M1 existing in the region 150A at the bottom of the SFP has a temperature T1 and a pressure P1, and is irradiated with gamma rays γ1 from the spent fuel 100. When the iodine ions I ^- in the pool water M1 present in the area 150A at the bottom of the SFP are irradiated with a high dose of gamma rays γ1, some of them react and become gaseous iodine molecules I ₂ (gas), which increases buoyancy. and rise through the pool water.

The gaseous iodine molecules I ₂ (gas) rising in the pool water reach the area 150B on the SFP water surface side. The pool water M2 in the area 150B on the SFP water surface side has a temperature T2 and a pressure P2, and is irradiated with gamma rays γ2. Here, temperature T2<T1 and pressure P2<P1. Further, the dose of gamma ray γ2 is sufficiently lower than the dose of gamma ray γ1. In addition to being released from the pool water M, gaseous iodine in the pool water M2 is partially dissolved in the pool water M2 as iodine molecules I ₂ (aq) or redissolved in the pool water to become iodine ions I ^-. form an equilibrium state.

In this way, the iodine in the pool water M in which iodine is dissolved in the SFP 150 forms an equilibrium state under the area 150A near the spent fuel in the area 150A at the bottom of the SFP, and is irradiated with a high dose of gamma rays γ1. After some of them become gaseous iodine molecules I ₂ (gas), they move to the region 150B on the water surface side of the SFP and form an equilibrium state again in an environment relatively far from the spent fuel 100. A part of it is released from the pool water M as gaseous iodine molecules I ₂ (gas).

The iodine behavior confirmation device 20 according to this embodiment can configure an environment that simulates the above-mentioned SFP. That is, the container 150 and the connecting pipe 160 of the iodine behavior confirmation device 20 simulate SFP, the solution M simulates pool water, and the radiation source 100 simulates spent fuel. In addition, by moving the radiation source 100 relative to the container 150, the dose of gamma rays irradiated is set to a predetermined threshold value or less, and the area 150A at the bottom of the SFP where the dose is high and the area 150B where the dose is low on the water surface side of the SFP are separated. to simulate. Here, the region 150A at the bottom of the SFP is simulated as a first state, and the region 150B on the water surface side of the SFP is simulated as a second state. Thereby, the iodine behavior confirmation device 20 can collect gaseous iodine released from the solution M by irradiating the solution M with radiation from the radiation source 100. This simulates the behavior of iodine from when gamma rays are irradiated to actual SFP pool water until gaseous iodine molecules I ₂ (gas) are released from the pool water. Since I ₂ (gas) can be collected, it becomes possible to appropriately evaluate gaseous iodine molecules I ₂ (gas) released from SFP pool water. Furthermore, it becomes possible to analyze the behavior of iodine within the SPF.

<Effects of each aspect>
The effects of the present disclosure will be explained for each aspect below. The iodine behavior confirmation device 20 according to the first aspect of the present disclosure includes a container 150 containing a solution M in which iodine is dissolved, a radiation source 100 that irradiates the solution M in the container 150 with gamma rays, and irradiation from the radiation source 100. It has a connecting pipe 160 through which gaseous iodine released from the solution M flows, and a collection section 170 connected to the connecting pipe 160 to collect the iodine.

Thereby, the iodine behavior confirmation device 20 irradiates the solution M in which iodine is dissolved in the container 150 with radiation from the radiation source 100 and causes the gaseous iodine released from the solution M to flow through the connecting pipe 160. The amount of gaseous iodine released from the solution M can be appropriately evaluated.

The iodine behavior confirmation device 20 according to the second aspect of the present disclosure is the iodine behavior confirmation device 20 according to the first aspect, in which the connecting pipe 160 includes a valve 162 that closes the flow from the collection section 170 to the container 150. has.

As a result, in the iodine behavior confirmation device 20, the flow from the collecting section 170 side of the connecting pipe 160 to the container 150 side is closed by the valve 162, so that the iodine behavior confirmation device 20 allows the flow from the collecting section 170 side of the connecting pipe 160 to the container 150 side. There's nothing to do. Moreover, it becomes possible to easily switch between a closed state in which the connecting pipe 160 is closed by the valve 162 and an open state.

The iodine behavior confirmation device 20 according to the third aspect of the present disclosure is the iodine behavior confirmation device 20 according to the second aspect, in which the valve 162 has a predetermined cracking rate for the flow from the container 150 to the collection section 170. This is a check valve 162 having pressure.

As a result, when inert gas is supplied from the inert gas supply section 140 into the inside of the connecting pipe 160, the iodine behavior confirmation device 20 opens the check valve 162 with the inert gas having a cracking pressure or higher, and connects the connecting pipe. It is possible to circulate the inside of the pipe 160 in the direction from the container 150 to the collecting section 170 .

An iodine behavior confirmation device 20 according to a fourth aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to third aspects, in which the collection unit 170 is connected to the connecting pipe 160. A first collecting section 170A is connected to collect the liquid component flowing through the connecting pipe 160 together with gaseous iodine, and a strong basic collecting section is connected to the first collecting section 170A and contains a collecting liquid therein. It includes a second collection section 170B in which the solution is stored.

Thereby, the iodine behavior confirmation device 20 prevents the liquid component released from the solution M in the container 150 from mixing into the strong basic solution that is the collection liquid W stored in the second collection section 170B. Since there is no iodine, the iodine behavior confirmation device 20 can appropriately measure iodine.

An iodine behavior confirmation device 20 according to a fifth aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to fourth aspects, in which the strong basic solution contains potassium hydroxide. It is a solution.

As a result, the iodine behavior confirmation device 20 can collect gaseous iodine by well dissolving it in potassium hydroxide, since the strong basic solution that is the collection liquid W is a solution containing potassium hydroxide. . Thereby, by measuring the collection liquid W, it becomes possible to appropriately measure gaseous iodine released from the solution M.

An iodine behavior confirmation device 20 according to a sixth aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to fifth aspects, in which the radiation source 100 includes a container 150, a connecting pipe 160 and the gas recovery section 110 including the collection section 170 are irradiated with radiation.

Thereby, the iodine behavior confirmation device 20 can cause the radiation source 100 to irradiate the iodine present in the container 150, the connecting pipe 160, and the collection section 170 that constitute the gas recovery section 110. This can prevent the iodine in the connecting pipe 160 from being redissolved in the solution M in the container 150.

In the iodine behavior confirmation device 20 according to the seventh aspect of the present disclosure, in the iodine behavior confirmation device 20 according to any one of the first to sixth aspects, the radiation irradiated from the radiation source 100 is They are gamma rays.

Thereby, the iodine behavior confirmation device 20 can irradiate the solution M in which iodine is dissolved in the container 150 with gamma rays from the radiation source 100.

The iodine behavior confirmation device 20 according to the eighth aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to seventh aspects, in which the container 150 and the radiation source 100 are moved relative to each other. By doing so, a first state in which a predetermined dose of radiation is irradiated from the radiation source 100 to the solution M in the container 150, and a lower dose of radiation from the radiation source 100 than in the first state are irradiated in the container 150. It is possible to switch between the second state and the second state in which the solution M is irradiated.

Thereby, the iodine behavior confirmation device 20 allows the container 150 and the radiation source 100 to move relative to each other to change the separation distance D, so that a predetermined dose of radiation is delivered from the radiation source 100 to the solution M in the container 150. Since the first state in which the solution M in the container 150 is irradiated and the second state in which the solution M in the container 150 is irradiated with a lower dose of radiation from the radiation source 100 than in the first state, the solution M in the container 150 can be switched. The dose of radiation irradiated to the solution M can be varied. This reproduces the state of the SFP bottom region 150A, which is irradiated with high doses of gamma rays from spent fuel, and the state of the SFP water surface region 150B, which is irradiated with low doses of gamma rays, in the actual SFP. becomes possible.

An iodine behavior confirmation device 20 according to a ninth aspect of the present disclosure is the iodine behavior confirmation device 20 according to the eighth aspect, in which the drive unit 120 adjusts the speed of relative movement between the container 150 and the radiation source 100. It is possible.

Thereby, the iodine behavior confirmation device 20 can change the moving speed when the container 150 and the radiation source 100 move relative to each other. As a result, the iodine that has been irradiated with gamma rays and has become gaseous in the area 150A at the bottom of the SFP where the spent fuel is stored in the actual SFP rises in the pool water M and moves to the area 150B on the water surface side of the SFP. It becomes possible to reproduce the situation.

An iodine behavior confirmation device 20 according to a tenth aspect of the present disclosure adjusts the temperature of the solution M in the container 150 in the iodine behavior confirmation device 20 according to any one of the first to ninth aspects. A temperature adjustment section 152 is provided.

Thereby, the iodine behavior confirmation device 20 can adjust the temperature of the solution M in the container 150.

An iodine behavior confirmation device 20 according to an eleventh aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to tenth aspects, in which the acidity of the solution M in the container 150 is determined. A pH measuring device 154 is provided.

Thereby, the iodine behavior confirmation device 20 can acquire the acidity of the solution M in the container 150.

An iodine behavior confirmation device 20 according to a twelfth aspect of the present disclosure is the iodine behavior confirmation device 20 according to any one of the first to eleventh aspects, in which the connecting pipe 160 is It has an inert gas supply section 140 that supplies inert gas for purging.

Thereby, the iodine behavior confirmation device 20 purges the inside of the connecting pipe 160 with the inert gas supplied from the inert gas supply unit 140, and captures gaseous iodine inside the connecting pipe 160 in the collection unit 170. Therefore, iodine can be collected appropriately.

An iodine behavior confirmation device 20 according to a thirteenth aspect of the present disclosure includes a container 150, a connecting pipe 160, and a collection tube. The portion of the portion 170 that comes into contact with iodine is made of a glass-based material.

Thereby, each part of the iodine behavior confirmation device 20 is not corroded by iodine, so that the gaseous iodine released from the solution M can be appropriately collected.

The iodine behavior confirmation system 10 according to the fourteenth aspect of the present disclosure includes the iodine behavior confirmation device 20 according to any one of the first to thirteenth aspects, and the iodine behavior confirmation device 20 that collects iodine. and a measuring device 30 for measuring iodine.

Thereby, the iodine behavior confirmation system 10 can measure the iodine collected by the iodine behavior confirmation device 20 with the measuring device 30.

A method for confirming iodine behavior according to a fifteenth aspect of the present disclosure includes a method for confirming iodine behavior from a radiation source 100 into a container 150 using the apparatus 20 for confirming iodine behavior according to any one of the first to thirteenth aspects. A step (S10) of irradiating the solution M with radiation to release gaseous iodine from the container 150 in the container 150, and controlling the dose of radiation to the solution M in the container 150 for a predetermined time. (S12), and a step (S16) of collecting iodine released from the solution M in the collection unit 170.

Thereby, the iodine behavior confirmation method can achieve the same effects as the first aspect.

In the iodine behavior confirmation method according to the 16th aspect of the present disclosure, in the iodine behavior confirmation method described in the 15th aspect, iodine collected by the collection unit 170 is measured (S18).

Thereby, the iodine behavior confirmation method can achieve the same effects as the fourteenth aspect.

10 Iodine behavior confirmation system 20 Iodine behavior confirmation device 30 Measuring device 100 Radiation source 110 Gas recovery section 120 Drive section 130, 182 Control section 140 Inert gas supply section 150 Container 152 Temperature adjustment section 152A Thermometer 152B Heater 154 pH measuring device 160 Connecting pipe 160A Between the water surface of the solution and the check valve of the connecting pipe 160B Between the check valve of the connecting pipe and the other end in the collection section 162 Check valve, valve 170 Collection section 170A First collection section 170B Second collection section 170C Vent pipe 170D Exhaust pipe 180 Measurement section 184 Display section 186 Output section D Separation distance M Solution P1, P2 Pool water pressure T1, T2 Pool water temperature W Collection liquid γ1, γ2 Gamma ray dose

Claims (15)

A container containing a solution containing dissolved iodine,
a radiation source that irradiates the solution in the container;
a connecting pipe through which the gaseous iodine released from the solution by irradiation from the radiation source flows;
a collection unit connected to the connecting pipe and collecting the iodine;
has
The radiation source is an iodine behavior confirmation device that irradiates a gas recovery section including the container, the connecting pipe, and the collection section with radiation . A container containing a solution containing dissolved iodine,
a radiation source that irradiates the solution in the container;
a connecting pipe through which the gaseous iodine released from the solution by irradiation from the radiation source flows;
a collection unit connected to the connecting pipe and collecting the iodine;
has
A first state in which the solution in the container is irradiated with a predetermined dose of radiation from the radiation source by relatively moving the container and the radiation source; and a first state in which the solution in the container is irradiated with a predetermined dose of radiation from the radiation source. An iodine behavior confirmation device capable of switching between a second state in which a lower dose of radiation is irradiated to the solution in the container . The iodine behavior confirmation device according to claim 2 , wherein the speed of relative movement between the container and the radiation source can be adjusted. The iodine behavior confirmation device according to any one of claims 1 to 3, wherein the connecting pipe includes a valve that closes flow from the collection section to the container. The iodine behavior confirmation device according to claim 4 , wherein the valve is a check valve having a predetermined cracking pressure for flow from the container to the collection section. The collecting section is connected to the connecting pipe and collects the liquid component flowing through the connecting pipe together with the gaseous iodine;
The iodine behavior confirmation device according to any one of claims 1 to 5 , further comprising a second collection unit connected to the first collection unit and storing a strong basic solution therein. The iodine behavior confirmation device according to claim 6 , wherein the strongly basic solution is a solution containing potassium hydroxide. The iodine behavior confirmation device according to any one of claims 1 to 7 , wherein the radiation emitted from the radiation source is a gamma ray. The iodine behavior confirmation device according to any one of claims 1 to 8 , wherein the connecting pipe includes an inert gas supply section that supplies an inert gas for purging the inside of the connecting pipe. The iodine behavior confirmation device according to any one of claims 1 to 9 , further comprising a temperature regulator that adjusts the temperature of the solution in the container. The iodine behavior confirmation device according to any one of claims 1 to 10 , comprising a pH meter that measures the acidity of the solution in the container. The iodine behavior confirmation device according to any one of claims 1 to 11 , wherein portions of the container, the connecting pipe, and the collecting section that come into contact with the iodine are made of a glass-based material. An iodine behavior confirmation system comprising: the iodine behavior confirmation device according to any one of claims 1 to 12 ; and a measuring device that measures the iodine collected by the iodine behavior confirmation device. The iodine behavior confirmation device according to any one of claims 1 to 12 is used to irradiate the solution in the container with radiation from the radiation source to remove gas from the container in the container. releasing the iodine of
For a predetermined period of time, the irradiation of the radiation to the solution in the container is below a predetermined threshold;
A method for confirming iodine behavior, comprising the step of collecting the iodine released from the solution in the collecting section. The method for confirming iodine behavior according to claim 14 , wherein the iodine collected by the collecting section is measured.

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