JPS5844012B2 - Isotope exchange reactor - Google Patents

Description

[Detailed description of the invention] The present invention relates to an isotope exchange reaction device.

In particular, it relates to an isotope exchange reactor having a low temperature bath and a high temperature column.

Since heavy water reactors use heavy water as a moderator, tritium T is easily generated by the action of neutrons ((n, r) reaction).

Tritium is a radioactive isotope of hydrogen, and its behavior is very similar to that of hydrogen.

In heavy water, it exists in the form of tritium oxide (tritiated water).

If the proportion of such tritiated water increases, when heavy water containing tritiated water leaks from the heavy water reactor system or during maintenance and inspection of the heavy water reactor (particularly when replacing system piping), workers may absorb tritium into their bodies. There is a risk of

To avoid such a situation, it is safe to install a tritium removal device in a heavy water reactor.

Isotope exchange reactions are generally used as a method for separating and recovering deuterium and tritium T as hydrogen isotopes contained in light water (H2O).

One such method is the dual temperature exchange method. The dual temperature exchange method combines a low-temperature column and a high base in a cascade, and has high hydrogen isotope separation efficiency and can recover hydrogen isotopes at a high concentration.

In this double temperature exchange method, a method using light water and hydrogen sulfide gas (hereinafter referred to as the G-8 method) is appropriately +-j L,
A heavy water production process has been proposed.

(' Nuclear Chemical Engine
, :ering //.

P 459-4.62. Published in 1957).

In the G-8 method, a low-temperature column with a perforated plate inside and a high base are placed in a direct column (1), and light water containing deuterium is transferred from the low-temperature column to the high base, and hydrogen sulfide gas is transferred from the high-base to the low base. During hot bath σζ flow, light water and hydrogen sulfide gas are brought into countercurrent contact in each column to perform an isotope exchange reaction.

Hydrogen sulfide gas flowing out of the cryotower is fed back to the high base.

In the low-temperature column, isotope exchange reactions of the following formula (1) and in the case of a high base, the following formula (2) are carried out.

HO+ )-(DS→HDO+ 1.(2S
・・・・・・(1) FIIDO+H2S-+F■20+
FIDS ・・・・・・(2) The above-mentioned 'Nu
clearChemicalEngineeri
ng“.

P460, Fig 11.21. As described in , deuterium in light water is concentrated in a cryogenic column, and deuterium in light water is diluted in a high base.

A portion of the light water with a high content of heavy water discharged from the low-temperature tower is taken out.

The remaining light water is fed to the high base.

The operating conditions of the isotope exchange reactor for the G-8 method are that the reaction temperature of the low-temperature column is approximately 30°C, and the reaction temperature of the high base is approximately 130°C.
The pressure inside one device is 20 atm.

The isotope exchange method performed between liquid water and hydrogen sulfide gas, such as the G-8 method, has the advantage that the reaction rate of the isotope exchange reaction is fast.

However, it has the disadvantage that the hydrogen isotope element separation coefficient determined from chemical equilibrium is small.

On the other hand, an isotope exchange reaction between liquid water and hydrogen gas has been considered.

This isotope exchange reaction using liquid water and hydrogen gas has the excellent advantage of having a large separation coefficient for hydrogen isotopes and being able to concentrate hydrogen isotopes to a high concentration.

On the other hand, it has the disadvantage that the reaction rate of the isotope exchange reaction is low.

The drawbacks of this isotope exchange reaction using liquid water and hydrogen gas have been improved through the development of catalysts.

However, it is desired to further improve the reaction efficiency of isotope exchange reactions using liquid water and hydrogen gas.

In view of the above circumstances, an object of the present invention is to improve the reaction efficiency of an isotope exchange reaction using liquid water and hydrogen gas.

The present invention is characterized in that the low-temperature tower includes a mist generation section that turns treated water containing hydrogen isotopes into a mist, and a process in which a reaction gas containing at least one of hydrogen gas and deuterium gas is discharged from the mist generation section. A steam generating section that converts high base or treated water into steam, consisting of a first catalyst filling section to which a water mist is supplied to promote the isotope exchange reaction, and a mist removing section that removes the mist from the reaction gas. a second catalyst filling section for promoting an isotope exchange reaction to which a reaction gas containing at least one of hydrogen and deuterium gas and steam discharged from the steam generation section are supplied; and steam for removing steam from the reaction gas. and a removing section.

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 5 show a preferred embodiment of the present invention; Figure 1 is a system diagram of a tritium removal device for a heavy water reactor to which the isotope exchange reaction device is applied; Figure 1 shows a detailed system diagram of the low-temperature column in the tritium removal equipment, Figure 3 shows a detailed system diagram of the high base in the tritium removal equipment shown in Figure 1, and Figure 4 shows the treated water and isotope exchange reaction rate in the low-temperature tower. FIG. 5 is a characteristic diagram showing the relationship between treated water and isotope exchange reaction rate in a high base.

FIG. 6 shows a system diagram of a tritium removal apparatus according to another embodiment of the present invention.

In the present invention, by turning water into mist-like fine particles in a low-temperature tower and entraining it with hydrogen gas, and by turning water into steam in a high base and entraining it with hydrogen gas, the gas-liquid contact is made uniform and the treatment is carried out. At the same time, increase in quantity should be achieved.

Mist refers to a liquid that exists in a state suspended in a gas.

FIG. 1 shows the system of a tritium removal device for a heavy water reactor.

1 is a heavy water reactor. The tritium removal apparatus includes an isotope exchange reactor 2 having a low temperature bath 3 and a high base 20, and an isotope exchange reactor 3 having a low temperature bath 40 and a high base 41.
9.

One isotope exchange reaction device 2 is a tritium enrichment section, and the other isotope exchange reaction device 39 is a tritium removal section.

Pipes 42 and 43 through which heavy water flows connect the heavy water reactor 1, the low temperature bath 3, and the high base 20, respectively.

Pipes 45 and 46 through which heavy water flows connect the low temperature bath 40, the high base 41, and the heavy water reactor.

Piping 44 connects low temperature bath 20 and piping 45, and piping 52 connects piping 46 and high base 40, respectively.

Pipes 60 and 61 through which hydrogen gas flows form a closed loop connecting low temperature bath 40 and high base 41.

Pipes 48, 49 and 50 through which hydrogen gas flows sequentially connect the high base 20, the low temperature bath 3 and the pipe 45.

47 is a heavy water extraction pipe.

The structure of the low temperature bath 3 will be explained in detail based on FIG. 2.

The low-temperature bath 3 has a 14-stage low-temperature column section composed of a pair of a reaction column 4 and a mist generator 7.

That is, the low temperature bath 3 has 14 reaction towers 4A, 4B, .
..., 4N and mist generator 7A.

7B, . . . , 7N.

The mist generator 7 is arranged upstream of the reaction tower 4 with respect to the flow of the mixed fluid of hydrogen gas and mist.

A hydrophobic catalyst layer 5 and a mist separator 6 are provided in each reaction column 4.

The hydrophobic catalyst layer 5 is located upstream of the mist separator 6 with respect to the flow of the mixed fluid of hydrogen gas and mist.

An ultrasonic oscillator 9 is provided within a container 8 of the mist generator 7.

Heavy water 51 is accumulated in the reaction tower 4 and container 8.

Although not shown, a mist generator 7C1, a reaction tower 4C1, a mist generator 7 is provided between the reaction tower 4B and the mist generator 7N.
D, reactor 4D1..., mist generator 7L.

Reaction Tower 4L1 Eleven mist generators 7 and eleven reaction towers 4 are arranged alternately in the order of mist generator 7M and reaction tower 4M.

Mist generators 7A and 7B. ..., spaces 14A, 14B, ... above the liquid level 13 of heavy water 51 in the 7N container 8.
. . , 14N are formed, respectively.

The spaces 16A, 16B, . . . , 16N are located above the hydrophobic catalyst layer 5 and form the reaction towers 4A, 4B.

, 4N, respectively.

Space 17A. 17B, .
B...

4N respectively.

Piping 10A connects space 14A and space 16A to piping 10B.
connects the space 14B and the space 16B, and the respective connections are made in the same manner, and the pipe 1ON connects the space 14N and the space 16N.

Piping 11A connects the bottom of reaction column 4A and container 8 of mist generator 7B.

Similarly, the pipe 11B connects the bottom of the reaction tower 4B and the container 8 of the mist generator 7C, and similar connections are made thereafter, and the pipe 11M connects the bottom of the reaction tower 4M and the container 8 of the mist generator 7N, respectively. do.

Further, the pipe 12B connects the space 14A, the pipe 12C connects the space 17C and the space 14B, and similar connections are made thereafter, and the pipe 12N connects the space 17N and the space 14M, respectively.

The pipe 50 connects the space 17 of the reaction tower 4A that constitutes the low temperature bath 3.
A will be contacted.

Next, the detailed structure of the high base 20 will be explained based on FIG.

The high base 3 has a 12-stage high-temperature column section constituted by a pair of a reaction column 21 and a steam condensation section 25.

The vapor condensation section 25 is located downstream of the reaction tower 21 with respect to the flow of the mixed fluid of hydrogen gas and steam.

A cooler 26 is inserted into a container 30 of the vapor condensation section 25, and heavy water 31 is present.

The steam generating section 22 and the hydrophilic catalyst layer 24 are connected to the reaction tower 21.
located within.

The hydrophilic catalyst layer 24 is located downstream of the steam generation section 22 with respect to the flow of the mixed fluid of hydrogen gas and water vapor.

The steam generator 22 is provided with a heater 23 .

Heavy water 29 exists in the steam generation section 22 and the steam condensation section 25 .

Although not shown, the reaction tower 21B and the steam condensing section 25L
Between the steam condensing section 25C1 reaction tower 21C1 steam condensing section 25D1 reaction tower 21D1..., steam condensing section 25J
The steam condensing section 25 and the reaction tower 21 are arranged alternately in the following order: 1 reaction column 21J1 steam condensing section 25 and the reaction column 21.

Spaces 32A, 32B, . . . , 32L are formed above the hydrophilic catalyst layer 24 within the reaction towers 21A, 21B, . . . , 21L, respectively.

Spaces 33A, 33B. ..., 33L is the reaction tower 21
between the liquid level of heavy water 29 in the reactor tower 21A and the hydrophilic catalyst layer 24.

21B, . . . , 21L, respectively.

Spaces 34A, 34B, . . . , 34L are formed in the containers 30 of the steam condensing sections 25A, 25B, .

Piping 27A connects the steam condensing section 25A and the steam generating section 22 of the reaction tower 21A, and piping 27B connects the steam condensing section 25B and the reaction tower 2.
1A is connected to the steam generating section 22, and the same piping is used thereafter, and the piping 27L is connected to the steam condensing section 25L and the reaction column 2.
The 1L steam generating sections 22 are connected to each other.

Piping 28A connects the steam generating section 22 and steam condensing section 25B of the reaction tower 21A, and piping 28B connects the reaction tower 21B.
The steam generating section 22 and the steam condensing section 25C are connected, and similar connections are made thereafter to connect the steam generating section 22 and the steam condensing section 25L of the reaction tower 21 to the piping 28, respectively.

The pipes 29A, 29B, ..., 29K connect the space 33A and the entire space 34B, the space 33B and the space 34C, and thereafter perform the same communication to connect the space 34 and the space 34L, respectively. .

The piping 31A connects the steam condensing part 25A and the space 32A, the piping 31B connects the steam condensing part 25B and the space 32B, and the same communication is performed thereafter, and the piping 31L connects the steam condensing part 25L and the space 32L, respectively.

Piping 31A. One end of each of 31B, ..., 31L is
Space 34A.

The steam condensing section 25A passes through 34B, . . . , 34L.

25B, . . . , are inserted into heavy water 29 in a 25L container 30.

Therefore, the heavy water 29 in the container 30 is removed from the pipes 31A and 31.
B,..., does not flow back into 31L.

A pipe 43 connected to the bottom of the reaction column 17N of the low temperature bath 3 is connected to the steam condensing section 25A of the high temperature bath 20.

A pipe 49 connected to the space 14N existing in the mist generator 7N of the low temperature bath 3 is connected to the steam condensing section 25A of the high temperature bath 20.
It is connected to the space 34A inside.

The aforementioned pipes 44 and 48 are connected to the reaction tower 2 of the high temperature bath 20.
It is connected to the steam generating section 22 and the space 33L within 1L, respectively.

The configurations of low temperature baths 40 and 41 are the same as those of low temperature bath 3 and high temperature bath 20.

The aforementioned tritium removal device is 1001. /hr of heavy water, and has the characteristics of a concentration level of 10 and a decontamination coefficient of 10.

The separation factor per column for the low and high temperature baths is 10.

The operation of this tritium removal device will be explained below.

Heavy water with a tritium concentration of 1 is taken out from the heavy water reactor 1,
The mist generator IA of the low temperature bath 3 is supplied through the pipe 42.

The heavy water 29 in the mist generator TA is turned into a mist by vibrating an ultrasonic oscillator (plate-shaped with a diameter of 50 mm) 21 made of barium titanate.

The particle size of the mist is approximately 1 μ.

The flow diameter of the mist can be adjusted in the range of 0.1 to 50μ by changing the frequency of the ultrasonic oscillator 21.

The mist of heavy water containing tritium generated in the mist generator 7A is supplied to the mist generator IA through the pipe 12B together with the deuterium gas containing tritium in the pipe 10A.
, and is supplied to the space 16A in the reaction tower 4A.

Deuterium gas has the function of transporting mist.

The deuterium gas containing the heavy water mist reaches the hydrophobic catalyst layer 17 of the reaction tower 4A, where an isotope exchange reaction as shown in equation (3) is carried out.

D20 (mist) + DT (gas) → DTO (mist) ” D2 (gas) ・・・・
...(3) The temperature of the reaction tower 4A is 30°C.

The temperature of the other reaction tower 4 in the low temperature bath 3 is also 30°C.

The pressure within the low temperature bath 3 is latm.

The heavy water mist with increased tritium concentration due to the isotope exchange reaction passes through the hydrophobic catalyst and then passes through the mist separator 6.
removed by

The deuterium gas with a reduced tritium concentration flows into the pipe 50.

The heavy water mist removed by the mist separator 6 falls into the liquid layer of heavy water 29 at the bottom of the reaction tower 4A.

The heavy water 29 present at the bottom of the reaction tower 4A and having an increased tritium concentration flows out to the pipe 11A.

After that, the heavy water is supplied to the mist generator 7B1, the reaction tower 4B1, and the mist generator 7C.

Reaction tower 4C,..., mist generator 7N and reaction tower 7
It passes through them in order of N.

As a result, the operations of forming heavy water into a mist, mixing the heavy water mist into the deuterium gas, the isotope exchange reaction of equation (3), and removing the heavy water mist from the deuterium gas as described above are repeated, and the low temperature bath 3 The concentration of tritium in the heavy water passing through increases gradually.

Deuterium gas (containing 9 ppm tritium) discharged from the steam condensing section 25A of the high temperature bath 20 into the pipe 49 is first introduced into the mist generator 7N of the low temperature bath 3.

This deuterium gas is then sent to a reaction tower 4N and a mist generator 7M.

Reaction tower 4M1 mist generator? L,... Mist generator 7B, reaction tower 4B1, mist generator 7A, and reaction tower 4A
It passes through them in this order.

This causes the contamination of heavy water mist like the one mentioned above, (3)
The three operations of isotope exchange reaction and removal of heavy water mist in the formula are repeated, and the tritium concentration in the deuterium gas passing through the low temperature bath 3 gradually decreases.

By performing the isotope exchange reaction in each low-temperature column section in this way, the tritium concentration in the deuterium gas discharged from the low-temperature bath 3, that is, the deuterium gas discharged from the reaction column 4A to the pipe 50, is It becomes 0.9 pμ.

Further, the tritium concentration in the heavy water discharged from the low-temperature bath 3, that is, the heavy water discharged from the reaction tower 7N to the pipe 43, is 101]IM11.

Heavy water containing ioppm tritium flowing through the pipe 43 is taken out through the pipe 47 and stored.

The remaining heavy water is introduced into the steam condensing part 25A of the high base 20 through the pipe 43, and the heavy water 29 in the steam condensing part 25A is
mixed into the

The temperature of the heavy water 29 in the container 30 of the steam condensing unit 25 is maintained at 80° C. by the cooling unit 26 .

Heavy water in the steam condensing section 25A is supplied to the steam generating section 22 of the reaction tower 21A through a pipe 27A.

The heavy water present in the steam generating section 22 is heated by the heater 23 and becomes steam at 100°C.

The pressure within the high temperature bath 20 is latm.

This water vapor is mixed with deuterium gas containing tritium, which is supplied from the steam condensing section 25B to the space 33A in the reaction tower 21A through the pipe 29A.

The heavy water vapor present in the space 33A is transferred to the hydrophilic catalyst layer 2 by a superheater (not shown) installed in the space 33A.
It is heated to about 250° C., which is the reaction temperature of No. 4.

Although the superheater is not shown, the space 33 of the reaction tower 21B
B, . . . are respectively installed in the space 33L of the reaction tower 21L.

A mixed fluid of deuterium gas and heavy water vapor is introduced into the hydrophilic catalyst layer 24 from the space 33A.

Within the hydrophilic catalyst layer 24, the isotope exchange reaction of formula (4) is performed.

DTO (water vapor) 10 D2 (gas) → D20 (water vapor) 10 DT (gas) ・・・・・・(
4) The mixed fluid of deuterium gas with increased tritium concentration and heavy water vapor with decreased tritium concentration is stored in space 32.
A and pipe 31A, and is discharged into heavy water 29 in steam condensing section 25A.

The heavy water vapor is completely condensed by the heavy water 29 in the steam condensing section 25A.

Deuterium gas reaches the space 34A and is discharged into the pipe 49.

The heavy water present in the steam generation section 22 of the reaction tower 21A is divided into steam condensation section 25B1 reaction tower 21B1 steam condensation section 25C1 reaction tower 21C1..., one in the steam generation section 25, one in the reaction tower 21, and one in the reaction tower 21.
It passes through the steam condensing section 25L and the reaction tower 21 in this order.

At that time, the heavy water flows while repeating steam generation in the steam generation section 22 of each reaction tower 21, an isotope exchange reaction with deuterium gas in the hydrophilic catalyst layer 24, and condensation of the heavy water vapor in the steam condensation section 25. do.

The tritium concentration in heavy water gradually decreases as it approaches the reaction tower 21K! 0, 911 flowing in the pipe 48
Deuterium gas containing tritium P is supplied into the reaction tower 21L of the high base 20.

This deuterium is supplied to the reaction tower 21L1, the steam condensing section 25L1, the reaction tower 21, the steam condensing section 25, the reaction tower 21B1, etc.
Steam condensing section 25B1 reaction tower 21A and steam condensing section 25
Pass through these areas in the order of A.

Deuterium gas gradually increases the tritium concentration while repeating the mixing of heavy water vapor, isotope exchange reaction, and heavy water vapor separation.

By supplying deuterium gas containing 0.9 ppm of tritium to the high base 20, the tritium concentration in the heavy water discharged from the high base 20, that is, the heavy water discharged from the reaction tower 21L into the pipe 44, is reduced to 1 m. descend.

The heavy water in the pipe 44 is mixed with 1 m of tritium-containing heavy water discharged from the low temperature bath 40 into the pipe 45 and supplied to the high base 41 .

Further, the high base 41 is supplied with deuterium gas which is discharged from the low-temperature bath 40 into the pipe 61 and contains tritium at 9 ppm and 9 ppm.

Between these heavy water and deuterium gas, the above-mentioned high base 20
The isotope exchange reaction is carried out in a similar manner.

Through the isotope exchange reaction, the tritium concentration in the heavy water discharged from the high base 41 to the pipe 46 is reduced to o, i ppm, and the tritium concentration in the deuterium gas discharged from the high base 41 to the pipe 60 is 0.9 ppI11. rises to.

The heavy water with a low tritium temperature flowing through the pipe 46 is returned to the heavy water reactor 1.

A portion of the heavy water flowing through the pipe 46 is supplied into the low temperature bath 40 through the pipe 52.

A portion of the deuterium gas discharged from the high base 41 into the pipe 60 flows into the pipe 48 .

Deuterium gas discharged from the low temperature bath 3 is mixed into the remaining deuterium gas flowing through the pipe 60.

These deuterium gases (tritium concentration: 0.9 ppm)
flows into the low temperature zone 40.

An isotope exchange reaction is carried out in the low temperature zone 40 in the same manner as in the low temperature bath 3.

Heavy water containing 1p￥U of tritium is discharged from the low temperature bath 40 into the pipe 45, and further into the pipe 61 at 0.09ppm.
Heavy water containing tritium is discharged.

In this example, heavy water mist and deuterium gas are subjected to an isotope exchange reaction in a hydrophobic catalyst layer in a low-temperature tower, and heavy water vapor and deuterium gas are isotopically exchanged in a hydrophilic catalyst layer in a high-temperature tower. Because the exchange reaction is carried out, the isotope exchange reaction efficiency is high.
The throughput of heavy water per unit volume of catalyst is increased in each of the low temperature bath and the high temperature tower.

FIGS. 4 and 5 are graphs of experimental results showing the relationship between the isotope exchange reaction rate and the flow rate of treated water in the low temperature bath and high temperature tower of the above-described example.

In this experiment, tritium 10 parts and light water 90 parts
% of the treated water was fed into the cold bath, and pure hydrogen gas was fed into the hot column.

The treated water flowing out from the low-temperature bath was led to the high-temperature tower, and the hydrogen gas flowing out from the high-temperature tower was led to the low-temperature bath.

As a hydrophobic catalyst in the low-temperature column, a porous tetrafluoroethylene tube (diameter 5 cm, length 5 cm, wall thickness 1 cm, porosity 5
A material in which platinum was supported at a weight of 0.5 weight was used.

As the hydrophilic catalyst in the high-temperature column, a nickel-chromium sponge metal plated with palladium at a plating amount of 8 Vl was used.

The temperature of the hydrophobic catalyst layer in the low temperature column was 30°C, and the temperature of the hydrophilic catalyst layer in the high temperature column was 250°C.

The hydrogen gas flow rate in the low temperature bath and high temperature tower is 1.2N.
m/h.

The isotope exchange reaction rate R (mo4/cc-cat-h) is expressed by the following equation as the number of moles of tritium transferred per unit time into hydrogen gas per unit volume of catalyst.

However, you is the tritium concentration in the hydrogen gas at the catalyst bed outlet, Yin is the tritium concentration in the hydrogen gas at the catalyst bed inlet, yeq is the tritium concentration in the hydrogen gas when the treated water and hydrogen gas reach equilibrium, and G is the flow rate of hydrogen gas, and ■ is the volume of the catalyst layer.

As is clear from FIG. 4, the isotope exchange reaction rate in the low-temperature bath of this example, indicated by characteristic (2), is significantly high.

Characteristic (■) indicates the reaction rate when the isotope exchange reaction with hydrogen gas is performed without turning the treated water into a mist.

Characteristic ■ is 10 times as large as characteristic ■.

This is based on the fact that the gas-liquid contact is made more uniform by turning the treated water into a mist.

The linear velocity of the isotope exchange reaction rate in the high-temperature column is twice that of the isotope exchange method in which the treated water is brought into countercurrent contact with hydrogen gas in liquid form, but since the treated water is vaporized, the characteristics shown in Figure 5 are as follows. As shown in ■, it is in a significantly high state.

Characteristic ■ is even higher than characteristic I.

The reaction efficiency of the hot column is higher than that of the cold bath.

From the above experimental results, it can be seen that the reaction efficiency in the low temperature bath and high temperature tower of this example is significantly increased.

The quantitative effects of the isotope exchange reaction apparatus 2 of the embodiment shown in FIG. 1 will be explained below.

The specifications of the isotope exchange reactor are: throughput of heavy water containing tritium: 1001/h; flow rate of deuterium gas: 15ON/h
, low temperature bath concentration 10. The decontamination coefficient of the high temperature tower is 101, the temperature of the low temperature tower is 30°C, and the temperature of the high temperature tower is 2'50°C.

In the case of tritium removal under such specification conditions, the shapes of the low temperature bath and high temperature column of the isotope exchange reactor 2 are as shown in the following table.

As is clear from this table, the isotope exchange reaction apparatus 2 of this example is an isotope exchange reaction apparatus that simply brings tritium-containing heavy water into countercurrent contact with deuterium gas in a low temperature bath having a catalyst layer and a high temperature column. Compared to X, the amount of catalyst packed can be significantly reduced, and the throughput per unit volume of catalyst can be significantly increased.

Furthermore, since the amount of catalyst is small, the device can be made compact.

In the latter isotope exchange reaction device

However, the operating pressure in this embodiment may be latm, and the risk of tritium leaking into the external region is significantly reduced.

The reason why the operating pressure can be set to latm in this example is that the reaction efficiency of the isotope exchange reactor 2 is extremely high.

The number of stages of the low temperature bath in the isotope exchange reactor 2 can be made smaller than that in the isotope exchange reactor X because 'Nuclea
rChemical Engineering”.

P460 Figll, 22. This is because the slope of the operating line (operating I 1ne) of the low temperature bath shown in can be increased.

Even when the isotope exchange reaction apparatus 39 shown in FIG. 1 uses the isotope exchange reaction apparatus X shown in Table 1, it is necessary to provide an isotope exchange reaction apparatus Y having the same shape as the isotope exchange reaction apparatus X.

In the above examples, a sponge metal catalyst was used as the hydrophilic catalyst, but in the present invention, a hydrophilic catalyst using a porous material such as ceramic or activated carbon, which has been commonly used as a carrier, may be used.

However, in this case, if the water vapor partial pressure in the reaction tower becomes supersaturated due to incorrect operation, water may condense in the pores of the catalyst carrier, resulting in a wet state and deactivation.

Furthermore, there is a problem that after getting wet with heavy water, water is strongly adsorbed, so dehydration and drying take a long time.

Therefore, when using such a catalyst, although the operating pressure is set below the saturated vapor pressure of the liquid in the high base, the risk of oversaturation of the partial pressure can be reduced.

Furthermore, if dry vapor is used as the highly basic liquid vapor, it is possible to prevent a decrease in catalytic performance due to wetting due to condensation.

Note that the sponge metal catalyst has the advantage that strong water aggregation does not occur because the carrier is not porous.

Another embodiment of the invention is shown in FIG.

Components that are the same as those in the embodiment shown in FIG. 1 are designated by the same reference numerals.

In this embodiment, independent closed-loop deuterium gas circulation lines are provided in the isotope exchange reactors 2 and 39, respectively.

That is, the isotope exchange reactor 39 has a deuterium gas circulation line formed by pipes 60 and 61.

The isotope exchange reactor 2 has a deuterium gas circulation line formed by pipes 49 and 62.

The pipe 62 communicates the space 17A in the reaction tower 4A of the low temperature bath 3 with the space 33L in the reaction tower 21L of the high base 20.

In this embodiment as well, the same effects as in the above-mentioned embodiments can be obtained.

Furthermore, in this embodiment, since the flow rate of deuterium gas in each of the isotope exchange reactors 2 and 39 can be adjusted independently,
It becomes easy to adjust the deuterium gas flow rate.

The present invention can be applied not only to tritium removal as described above, but also to the production of heavy water.

That is, by using the embodiment shown in FIG. 1 or FIG. 6 described above, the concentration of heavy water can be increased by performing an isotope exchange reaction between natural light water with a low content of heavy water and hydrogen gas.

That is, according to the present invention, as described above, the treated water is turned into mist in a low-temperature bath, and the treated water is vaporized with a high base to perform the isotope exchange reaction, so the reaction efficiency of the isotope exchange reaction is significantly increased. This effect can be achieved.

It should be noted that, as a matter of course, the illustrated embodiments are merely illustrative, and the present invention is not limited thereto.

[Brief explanation of drawings]

1 to 5 show an example of the implementation of the present invention, FIG. 1 is a system diagram of a tritium removal device for a heavy water reactor to which the isotope exchange reaction device is applied, and FIG. 2 is a tritium removal device shown in FIG. 1. Figure 3 is a detailed system diagram of the low-temperature bath of the removal equipment; Figure 3 is a detailed diagram of the high-temperature column of the tritium removal equipment shown in Figure 1; Figure 4 shows the relationship between the treated water in the low-temperature tower and the isotope exchange reaction rate. FIG. 5 is a characteristic diagram showing the relationship between treated water and isotope exchange reaction rate in a high-temperature column. FIG. 6 shows a system diagram of a separate tritium removal device of the present invention. 2... Isotope exchange reaction device (tritium enrichment section), 39... Isotope exchange reaction device (tritium enrichment section), 3.40... Low temperature tower, 20, 4...
...High temperature tower, 4゜4A, 4B, ..., 4N...
...First catalyst packed section (reaction tower, 6...Mist removal section (mist separator), 7°7A, 7B, ...,
7N...Mist generation section (mist generator), 21
．． 21A, 21B,..., 21L... Second catalyst packed section (reaction tower), 22... Steam generation section, 2
5... Steam removing section (steam condensing section).

Claims (1)

[Scope of Claims] 1. In an isotope exchange reaction apparatus having a low temperature bath and a high temperature column, the low temperature bath includes a mist generation section that turns treated water containing hydrogen isotopes into a mist, and a mist generation section that turns treated water containing hydrogen isotopes into a mist, and a first catalyst filling section for promoting an isotope exchange reaction to which a reaction gas containing at least one of hydrogen gas and deuterium gas and a mist of treated water discharged from the mist generating section are supplied; a mist removal section that removes the mist from the bath, a steam generation section in which the high-temperature tower converts treated water discharged from the low-temperature bath into steam, and a reaction gas containing at least one of hydrogen gas and deuterium gas. Consisting of a second catalyst filling section that promotes the isotope exchange reaction to which the steam of the treated water discharged from the steam generation section is supplied, and a steam removal section that removes the steam of the treated water from the reaction gas. An isotope exchange reaction device characterized by: 2. According to claim 1, the mist removing section is arranged downstream of the first catalyst filling section with respect to the flow direction of the mixed fluid of the treated water mist and the reaction gas. isotope exchange reactor. 3. Claim 1 or 2, characterized in that the catalyst present in the first catalyst filling section is a hydrophobic catalyst, and the catalyst present in the second catalyst filling section is a hydrophilic catalyst. The isotope exchange reaction device described in . 4. Claim 1 or 4, characterized in that the steam removing section is disposed downstream of the second catalyst filling section with respect to the flow direction of the mixed fluid of the steam of the treated water and the reaction gas. The isotope exchange reaction device according to item 2. 5. The isotope according to claim 4, wherein the catalyst present in the first catalyst filling part is a hydrophobic catalyst, and the catalyst present in the second catalyst filling part is a hydrophilic catalyst. Body exchange reaction device. 6 A first isotope exchange reaction element is constituted by the low temperature bath and the high temperature column, a second isotope exchange reaction element is constituted by the low temperature bath and the high temperature column, and the A first passage is provided for guiding treated water discharged from the high temperature column to the high temperature column of the second isotope exchange reaction element, and a portion of the treated water discharged from the high temperature column of the second isotope exchange reaction element is provided. Claim 1, characterized in that a second passage is provided for guiding the isotope exchange reaction element to the low temperature bath of the second isotope exchange reaction element.
The isotope exchange reaction device described in Section.