HUT54247A - Method and apparatus for processing waste solutions of nuclear power plants - Google Patents

Abstract

Low- and medium activity wastes comprising max. 50kg/m3 are treated by chemical pptn., filtration, pH adjustment, treatment of the soln. by selective reverse osmosis (boric acid/nitrates) followed by ion exchange sepn. of nitrate impurities from the radioactive boric acid portion, which can be returned to the chemical pptn. The recovered nitrate soln. can be used again

Description

The present invention relates to a process and an apparatus for the treatment of low and intermediate level radioactive waste solutions in nuclear power plants.

Low and intermediate level radioactive waste is defined as radioactive waste solutions of 3.7 x 105 Bq / dm ^ and 3.7 x 10 ^ Bq / dm ^ according to the guidelines of the International Atomic Energy Agency.

In addition to the trace amounts of radioactive impurities mentioned above, the radioactive wastes mentioned above are primarily boric acid, alkaline nitrates, alkaline hydroxides, colloids from corrosion products and other sources, calcium-magnesium salts causing water hardness,. sometimes organic materials - oxalic acid, citric acid, etc. as well as their salts, permanganate reduction degradation products, and other inorganic salts such as sulfates, phosphates, carbonates. The pH of the waste solutions is generally alkaline (pH 8-9) but may also be acidic.

It is obvious that the processing of liquid radioactive waste of very complex and variable composition and concentration is not an easy task, considering that the volume of liquid radioactive waste generated during operation of two VVER-440 reactor units can reach 40 000 m per year, according to design data. .

Liquid radioactive waste requires special handling, storage, embedding in solid matrix / solidification / and final disposal / burial, which is required for health and environmental reasons. Special treatment costs enormous costs, international data • · ·

- 3 rint 1 nr processing and storage cost of reinforced concrete waste approx. 3,000 ¢, which is rising rapidly at the current rate of investment and other costs, which is why nuclear power plants have a strong interest in reducing the volume of radioactive waste.

Methods known in the art and practiced employ evaporation or possibly minor chemical interventions (Hungarian Patent Nos. 185,105,105 and 192,209) to reduce the volume of liquid radioactive waste. However, the efficacy of these methods is limited, namely that the saline content of the waste solution limits the minimum amount of solidified final product available, since the salt concentration of the solidified final product is very limited due to mechanical properties and the tendency to % may.

On the basis of this finding, for the purposes of further reduction of volume, 3434/84. Hungarian Basic Patent Application No. 5,123,198, discloses the reduction of the salt content of radioactive waste solutions / non-radioactive / inactive *. The above process, as one of the most modern and commonly used processes, combines various otherwise known separation methods - precipitation separation, evaporation, filtration, ultrafiltration, ion exchange purification, crystallization and reverse osmosis - to produce three product streams of radioactive waste, namely radioactive industrial salt waste and radioactive waste containing up to half of the salinity of the initial waste.

Hungarian Patent No. 195,967 relates to the recovery of purified boric acid from nuclear power plant waste solutions by a three-step, only-linked, three-step reverse osmosis apparatus and special anion exchange columns operating at least two tanks in a hydrocarbonate cycle. The disadvantage of the process is that it can only be applied to virtually completely suspended solids solutions containing up to 10 g / dnr of boric acid and alkaline nitrate, which are the rarest in nuclear power plant practice. A disadvantage of this process is that the radioactive waste to be concreted contains 20-25-9% of the total nitrate and boric acid, thereby increasing the weight of the concrete and the risk of pitting.

It is an object of the present invention to overcome the above disadvantages, i.e., to reduce the weight of concrete required by improving the separation between radioactive waste and inactive salt.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for efficient treatment of nuclear power station radioactive waste, in particular, reducing chemical demand, more efficient separation of radioactive precipitation, material stream reduction, eliminating cumbersome separation steps such as crystallization and economically and economically combination.

The present invention relates to a process for the treatment of low and intermediate level nuclear radioactive waste solutions by chemical precipitation, filtration and selective reverse osmosis separation of the soluble salts.

5 and by ion exchange, so that a waste solution containing not more than 50 kg / m 2 of boric acid is required after pre-evaporation in step (i). precipitating, settling and decanting, then filtering and, after adjusting the pH, decomposing it into a boric acid and a nitrate stream in a boric acid / nitrate selective reverse osmosis separator; separating residual radioactive and nitrate contamination of the boric acid stream in an ion exchanger and draining the pure boric acid stream; dividing the nitrate stream into a radioactive stream and a purified nitrate stream in a reverse osmosis separator selective for divalent and polyvalent ions; returning the radioactive stream to chemical attack; removing the remaining radioactive contamination of the purified nitrate stream in an ion exchanger; and discharging the stream of radiochemically pure nitrate.

The invention further relates to an apparatus for carrying out the above process, characterized in that a distillate is connected to the waste solution receiving container, which is connected in part to a storage vessel and partly to a control vessel via a cation and anion exchanger; a reactor vessel, filter, pH adjusting ion exchanger, microfilter and reverse osmosis separator unit are connected to the storage vessel; the reverse osmosis separation unit is connected on the one hand to a cation and anion exchanger, on the other hand to a temporary storage tank and to a second reverse osmosis separation unit; the second reverse osmosis separation unit being connected to a selective ion exchanger, a complexing ion exchanger and a second control vessel on the one hand and a second temporary storage vessel connected to the storage vessel on the other.

• ············································································································································································································································ ·

The apparatus according to the invention is shown in Figure 1, the symbols used in the figure being as follows:

receiving tank evaporator storage tank reactor vessel filter pH adjusting ion exchanger microfilter reverse osmosis separator cation exchanger anion exchanger temporary storage tank second reverse osmosis separator selective ion exchanger complexing ion exchanger second checker

Product B stream

BE waste solution

BP residual current

B0 pure boric acid current

Cs 4 -Cs 2 precipitate

E ^, E ₂ industrial waste

I CS-1, ICS-2 exhausted ion exchanger

_{Χ χ} nitrate current 2 2 radioactive current

KO condensate

L - ^ - Lj Lugoldat

NI United Nitrate Stream

^P 1 Boric acid current ^P 2 purified nitrate stream R radioactive waste acid regenerate ^R 3 alkaline regenerate REC-1 - REC-3 return current ^S 0 partial flow δ-. , So acid solution SÜ concentrate SÜD sedimented waste solution TK, TK _± , TK2 dilution solution ^V 1 ··· V _n chemicals

The units in the illustration do not represent a device. In order to increase capacity or clean without stopping, it is possible to integrate several identical devices in one unit, either in series or in parallel.

The readioactive waste solutions generated during operation of the nuclear power plant have different origins in their bulk:

solutions resulting from organoleptic leakage resulting from changes in the boron concentration and containing essentially boric acid and corrosion products activated in the primary circuit; acidic, alkaline, alkaline nitrate and boric acid containing radioactive solutions derived from loosening, regeneration and washing of ion exchange filters; decontamination of NaOH, KMnO 4 and its reduction products, HNO, H-jBO, oxalic acid and / or citric acid, and their slurry salt solutions;

· ·················· · · · · · · · · · · · · · · · · · · · · · · · · · ·

- solutions of various compositions of inorganic leaks and other sources,

Separate collection of the above solutions, thus selectively, can result in a significant cost / chemical cleanup, the cost of which is higher tank space requirements.

Our method is suitable for the processing of both collectively and selectively collected radioactive waste solutions, the first step of which is to adjust the salt concentration of the waste solution for further processing;

The concentration of dilute boric acid in the receiving container 1, preferably selectively collected in the receiving vessel 1 of Fig. 1, and / or at a salt concentration of above, is concentrated in the evaporator 2 by evaporation, preferably from 10 to 15 kg / m 2, boric acid concentration range, thereby significantly reducing the mass of radioactivity-binding precipitates, while reducing the capacity of the processing equipment,

The concentrate / IU / is collected in the storage tank 3.

The condensate / KO / is fed through the cation exchanger 17 and the anion exchanger 18 to the control tank 19, depending on the degree of radioactivity, the condensate is returned to the receiving tank 1 on the branch indicated by stream REC-1, otherwise the clean condensate is disposed of ^ industrial waste / or part of it / TK stream / diluent and rinse water / TK ^, TK ₂ /.

Liquid radioactive waste solution concentrate is transferred from the storage vessel to the reactor vessel 4; So, regardless of the operations in the 4 reactor vessels, the 3 storage tanks. Collect the concentrate in a smooth · · · · · · container. In the case of a sufficiently large storage tank with a volume of 250-500 m 3, practical experience shows that the fluctuations in the composition of the hig waste solution give a dull, generally slightly alkaline, concentrate having a pH of 7-9. If the concentrate pH different from the pH adjustment chemical treatment is initiated and carried out V- ^, _V2, ··· ^{Vn V} 3 w ^ve adding ^agents as required as follows:

adjusting the pH to 7-9, preferably to pH 8, by adding alkali, preferably NaOH or mineral acid, preferably H ₂ SO 4 and / or HNO 4, if necessary;

for example, to decontaminate and decontaminate the solution, the following precipitating chemicals are added in a specific order and amount:

Order Precipitation, chemical mmole / rn Note limits

K ^ Mey / Εβ / 0Ν / θ7 0-200

Fe / OH / ₃ 0-200

BaS0 ₄ 0-1000

Mn0 / 0H / _z 200-4000

1-4

H ₂ 0 ₂ 0-100000 nonionic 0-50 polyelectrolyte preferably wherein: x = 0-2 y = 1-2

Me = Cu | ^, Co ²⁺ , Zn ^

200

1100 where: z = 1-2 and a precipitant on the one hand, KMnO. On the other hand a reducing agent, preferably oxalic acid, citric acid, h ₂ o ₂

2000 * concentration in g / m · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ««

- 10 AK ^ / Fe / CN / θ7 ^x 5H ₂ 0 / yellow blood salt / precipitates with Co, Fe, Mn ions in the radioactive waste solution, the decontaminating effect being Fe / III /, preferably

It is enhanced by the addition of Fe / NO 2/4 x 9H ₂ 0, which mainly promotes the separation of Fe and Co isotopes and ¹¹⁰ Ag. Copper / II /

ions, preferably CuSO 4 x 5H ₂ O, to precipitate Cu ₂ / Fe / CN / g7, which binds the

Cs-ions from an otherwise alkaline medium.

The sárgavérlugsóból substantially separated from a mixed FIey ^ K / Fe / CN / ^ Z precipitate ferrocyanide, which is ^^ "^^ Fe, θ ^" ^ θΟο, ^^ Mn, 1 ^ _S 4-1370, 110radioaktív ioztópokat or it binds at least 98% of these from the waste solution with high efficiency. The addition of a Ba salt, preferably BaCl ₂ x 2H ₂ O, or Ba / NO 2/2 and the addition of sulfate ions, precipitates a solution of BaSO 4 in the solution, which is capable of binding to the dioactive isotope.

Depending on the composition of the waste solution, if no dissolved Ca, Mg salt is present in the solution, the addition of oxalic acid is unnecessary.

KMnO ₂ oxidizes the excess oxalic acid, which does not form a precipitate, to CO ₂ . In H ₂ 0 ₂ alkaline media quickly,

Within 10-15 minutes, it reduces KMnO ^ and χη0 / 0Η / _χ precipitates with a high specific surface area, which also traps radioactive isotopes from the solution and traps the colloidal particles suspended in the solution.

To facilitate precipitation / coagulation / precipitation, a nonionic polyelectrolyte is added to the waste solution.

During the chemical treatment, the solution is stirred,

1 to 5 air / solution per hour air volume ··· * * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · also helps. After addition of the polyelectrolyte and homogenization of the solution, the stirring, i.e. the air supply, is stopped and the precipitate is settled. The sedimentation rate of the precipitate produced as above

1.5-2 m / h.

The sedimented precipitate (Cs 4, Cs 4) containing at least 98% of the radioactivity, except tritium, is discharged into the radioactive waste R as a stream.

The sedimented waste solution (SUD) is filtered from the floating material through a 3 micron pore filter 5 so that the pH adjuster 6 does not clog the precipitate if part of it is trapped by the liquid stream.

The precipitate remaining on the filter is flushed back into the reactor vessel 4 as a stream of Cs 2.

Given that the radioactive waste solution concentrate has been found to be optimal for alkaline and precipitate decontamination at pH 8, the boric acid / nitrate separation is optimal at pH 4-5, therefore the filtration performance of the 5 filters is optimal. The pH should be adjusted from 8 to pH 4-5. Adding a strong mineral acid to the solution to adjust the pH would result in a multiplication of the amount of alkali nitrate contaminants inherent in boric acid and make subsequent purification operations more difficult. Therefore, the pH adjustment is carried out on the cation exchange resin brought to the hydrogen form. A portion of the SÜD current is applied to the BR bypass and combined with this alkaline solution to obtain a pH of 99 99 9. acidic S _Q partial current coming from a setting ion exchanger. Adjusting S and _Q BP volume ratios, which depend upon the waste solution concentrate alkalinity, the desirable pH value is adjusted to 4-5.

The pH adjuster 6 is required for regeneration of the ion exchanger

An acidic solution, preferably nitric acid, is introduced into the combined nitrate stream NI via the regenerate line without impinging the BO boric acid stream.

Prior to the reverse osmosis separator 8, a microfilter 7 having a pore size of 1 to 0.1 microns is required for membrane protection. This removes crumbled ion-exchange resin particles, microcolloids, bacteria, which can be detrimental to membrane function and life.

Due to the ion exchange pH adjustment, a one or two stage 8 reverse osmosis separation unit was sufficient to separate the boric acid / nitrate. In the product stream B fed to the boric acid / nitrate selective 8 reverse osmosis separation unit, the water in the product stream is about 10%. 90% as permeate / P ^ boric acid current / membrane permeate, and the permeate contains 78-80% of boric acid, while only ^ 18 $ of nitrate. This makes it possible to recover boric acid economically from the waste solution. Thus, essentially with the reverse osmosis separation unit 8, a stream of boric acid-rich P1 and a nitrate-rich material is produced from the waste solution.

The P ^ boric acid stream is applied to the R-H Form Cation 9 or R-OH Form Anion Exchanger 10 for further purification and the boric acid is final ”, N0 ^ <0.1% / m / m / nitrate • · ····

- 13 discharges are implemented with an ion exchanger. / The membrane pre-purification is required because otherwise regeneration of too Sc.sup.2 R2, Rs. Would be required, but only the residual nitrate should be transferred to the ion exchangers 9, 10.

The BO pure stream of boric acid coming from the ion exchangers is a usable boric acid solution.

The cation exchanger 9 is regenerated with acid solution Sg, preferably HNO2, and the anion exchanger 10 is regenerated with L2 alkaline solution, preferably KOH, preferably countercurrent.

The streams AR1, K2, R8, R3 are combined in the N1 pooled nitrate stream and collected in the transitional storage tank 11, where the acidic regenerates R1, R8 react with the alkaline regenerator R1 and the pH fluctuation due to the intermittent nature of the regenerations , but ultimately the acidic effect of the NI pooled nitrate stream will be strongly acidic, so the solution is neutralized to pH 4-5 by addition of Lg lug solution, preferably NaOH, then the NI stream using up to 15 kg / m 2 salt concentration using pure TKg diluted.

The polyvalent ions are separated by the second reverse osmosis separator 12. This second reverse osmosis separation unit has at least 90%, preferably as high as possible percent rejection, for the divalent and polyvalent ions, while also having the lowest possible dispersion of alkali nitrates and boric acid.

The separation of trace amounts of polyvalent ions, typically Mn ^ ⁺ , Fe ^ ⁺ , ^ο ^ ⁺ , Sr ^ ⁺ , Ca ^ ⁺ , Mg ^ ⁺ , is required because of the better utilization of the complexing ion exchange capacity, i. • ·

- 14 ρ.

since the majority of Μη, Fe ^ ⁺ , Ca ^ ⁺ ions are non-radioactive, and ions derived from the water hardness of Ca ²⁺ , Mg would also unduly burden the complexing ion exchanger.

The combined nitrate stream NI is decomposed into a single-stage 12 reverse osmosis separator unit into a radioactive stream and a P1 purified nitrate stream. The concentrate / K i contains about 10% of the NI flow rate, with at least $ 90 of polyvalent radioactive and non-radioactive ions, with about 20% of the boric acid and nitrates / inactive salts entering. The permeate (P ₂ ) contains inactive salts, boric acid and nitrates entering the stream. 80% and approximately 90% of the NI flow rate.

The final decontamination, i.e. removal of traces of radioactivity, of purified nitrate stream 2, which is mainly nitrate and boric acid-free, is accomplished by selective ion exchangers 13 and 14. The inorganic ion exchanger 13 is an inorganic ion exchanger, which is also selective in alkaline medium for monovalent ions, especially Cs ⁺ and Ag ⁺ , and has been found to be optimal in the pH range of 4-6.

2+ 3+ 2+

Trace amounts of divalent and polyvalent ions such as Co, Pe 1, Sr are bound on 14 complexing ion exchangers. The operation of the resin has been found for ^ ° Sr ²⁺ is as extremely dangerous radioactive impurity optimal pH of about 8 surroundings, so lugadagolással, preferably NaOH al pH of the solution was adjusted to about pH 8.

Selective ion exchangers 13, 14 can be used to ensure that the required activity levels are lowered.

- the radioactivity of the purified nitrate stream P _{2 is} 15.

After collection and inspection into the 15 control tanks, the purified nitrate stream P _{2 is} discharged from the system as a non-radioactive E ₂ industrial waste below the appropriate activity level, and if its activity does not meet the standard due to some technical failure, the REC-2 the solution is returned to the storage tank 3

The spent ion exchanger ICS-1 and ICS-2 is disposed of in radioactive waste R. Due to the high selectivity and prior decontamination of the precipitate and the insertion of 12 units, the volume of the exhausted resin is 1-2 ng / year for a standard 1000 MW z power plant.

The radioactive stream K ₂ , which contains some of the radioactive isotopes in a concentrated form, is fed to the second temporary storage tank 16 where the salt concentration of the solution is diluted with pure condensate, if necessary, and adjusted to about 15 kg / nr. The solution with the appropriate salt concentration is fed through the REC-3 branch into the storage tank 3 at the beginning of the processing, whereby it is subjected to repeated precipitation decontamination as described above.

While the above steps are known per se, a preferred combination of these in accordance with the present invention results in a novel process which reduces the mass of radioactive waste to be embedded in an unpredictable manner to a person skilled in the art, thereby substantially exceeding the technical and economic performance of prior art is also supported by the following example.

- 16 • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

Example

Using empirical data from a VVER-type nuclear power plant / 2 units of Unit 44O, annual liquid radioactive waste is characterized by:

volume: 40,000 m ³ / year Concentrate of boric acid: 1.2 kg / m ³ NO ^ “- Concentration: alkaline ion concentration: 150 g / m ³ 7.2 moles / m ³ pH / v 8 total activity: ÍO ^ Bq / dm ³

/ 5 ⁸ - ⁶ ° Co, ⁵ Sta, ^110m Ag, ⁵⁹ Pe /

The waste solution is transferred from the receiving vessel 1 to the evaporator 2 and concentrated by evaporation to a concentration of 4000 m ³ , thereby concentrating the initial waste solution 10 times. The Sti concentrate of about 4000 m ³ / year is fed to the storage tank 5 and then to the reactor vessel 4.

Steam or condensate formed in the 2 evaporators is • z

It is passed through ion exchangers 17, 18 and used as a pure condensate at 56000 nr / year for dilution of TK = TK ₁ + TK ₂ , or it can be recycled elsewhere in the waste treatment system / E ^ /. The two evaporator decontamination factor DF = 10 around ^{the fifth}

Chemical treatment of the IU concentrate, decontamination by precipitation, is carried out in the reactor vessel 4 with stirring at a flow rate of about 50 N / h. The purpose of the chemical treatment, respectively, / V- ^ ... V _Q / chemicals are added to the süritményhe z

^V 1 44.2 g / m ⁵ K ₄ / Fe / CN / ₆ 7 x 3H ₂ 0 say 176.8 kg / year ^V 2 24.2 g / m ⁵ Fe / NO _5/5 x 9H ₂ 0, say 96.8 kg / year ^T 5 30 g / m ⁵ CuSO 4 x 5H ₂ O, say 120.0 kg / year ^V 4 50 g / m ⁵ Ba / NO _5/2, say 208.0 kg / year ^V 5 20 • z g / ur h ₂ so ₄ , say 80.0 kg / year ^V 6 187.4 g / m ⁵ KMn0 ₄ , say 749.6 kg / year ^V 7 0.2 DMW H ₂ 0 ₂ /30% /, say 800.0 dm ⁵ / year ^V 8 3 • z g / nr polyelectrolyte say 1.2 kg / year 8 Γ = 2232.4 kg / year

i = l

The resulting chemicals are formed from:

104 g / m ⁵ Mn0 / 0H / _z g / m ⁵ K ^ ey / Ée / CN / g?

g / m ⁵ BaSO ^

194 g / m ⁵ precipitation / radioactive /

CSj- + CSg + Cs ^ = 194 g / m ⁵ x 4000 m ⁵ / year = 776 kg / year; the

Thus, the radioactive concentration of about 10 10 Bq / dm ³ was reduced to close to 2000 Bq / dm ⁵ in the IU concentration.

After decontamination by precipitation, the SÜ concentrate is characterized by:

volume 4000 m ⁵ / year boric acid concentration 12 kg / m ⁵ alkali nitrate concentrate • 1.8 kg / m 2 free base 52.7 gmol / nr activity «> ^ 2 x 10 ⁵ Bq / dm ⁵

The precipitate is settled in the reactor vessel 4, the solution is filtered through 5 filters, the Cs ₂ filtrate is occasionally transferred ···

18 is vented into reactor vessel 4. The SUD sedimented waste solution is acidified with a hydrogen form pH adjusting ion exchanger and the S _Q solution is combined with the BP bypass to adjust the pH to 4-5.

For the regeneration of the pH adjusting ion exchanger 6, 343.7% (w / w) of S-HNO 2 is used at an annual rate of 1.3 times the chemical excess. Taking into account the rinse water, Rj = 770 m <3> / year regenerate which contains 17.85 t NaNO2 and 3.97 t HNO2.

The S + _Q BP solution was filtered and applied to the microfilter 7 egyfokozatu, boric acid / nitrate selective 8 reverse osmosis separation cartridge. The filtrate was rinsed back into reaction vessel 4. The operation of the 8 reverse osmosis separators is described in Table 1.

Table 1

Intake ^P 1 ^K 1 volume, m 4000 3600 400 • z concentration of boric acid, kg / nl 12 10.34 26.9 • z NaNO4 concentration, kg / nr 1.8 0.36 14.76 activity, Bq / dm ^ ^ 2000 ~ 400 ^ 16400

The P 4 boric acid stream / permeate is transferred to the ion exchanger 9, 10 and the residual alkali nitrate is removed from the solution to produce a pure pure boric acid stream BO in the primary circuit; 10.34 kg H 2 O 4 / m 2 x 3600 m 2 = 37.2 t / 77% / boric acid is recovered.

• · ···

- 19 9% cationic regenerating 28.8 m ^ / m / m / s per year using ₂ nitric acid 1.5-fold excess chemicals, which produce the IL, regenerate a volume of 70 t 1.29 m ^ cent NaNO and 0.48 t HNO0.

5

The anion exchanger 10 is regenerated with 25.6 m ^ / 5% / m / m KOH solution per year, resulting in a volume of 90 m regener, 1.5 t KNO ^ and 0.43 t KOH.

The Rj- + K- ^ + R ₂ + material streams form the NI single action nitrate stream, which is diluted in the temporary storage tank 11 and with TK ₂ condensate at 1546 µg / year. The acid

The NI nitrate stream was neutralized to pH 4-5 with 2.5 t / year L ₂ NaOH. The nitrate stream is then fed to the polyvalent ion separator 12 reverse osmosis separator. The operation of the apparatus is described in Table 2.

Table 2

Power supply P ₉

^ 2400

2424

268 activity

4.5

11.6

28.9 ~ 480 ~ 197β0

and then returned to REC 5 in storage tank 5 (768 nr.) and subjected to the above precipitation treatment. At this time, a Cs 4 = 149 kg radioactive precipitate was collected. Mass of total precipitation ··· ♦ • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·. · ·

- 20 Cs-j + Cs ₂ + Cs ^ + Cs ^ = 149 + 768 = 917 kg / year.

P ₂ purified nitrate stream / permeate is applied to the 13 selective ion exchanger and then 1.1 t / year L? NaOH was added as a pH of 8 and subsequently the purified nitrate stream was fed to the complexing ion exchanger 14. After the complexing ion exchanger 14, the activity of the pure nitrate stream is less than 50 Bq / dm, i.e., below the release limit. From the second control vessel 15, after the activity control E _2, the nitrate stream is discharged from the waste treatment system as industrial waste. If the activity of the solution is greater than 50 Bq / dm, it is fed back to storage tank 3 on the REG-2 branch.

Exhausted ion exchangers with ICS ^ = 1.2 t / y and ICS ₂ = 0.8 t / y with the radioactive product stream R = ICS ^ + ICS ₂ + Cs + Cs ₂ + Gs ^ + + Cs ^ = 2.92 t / years together for solidification - cementation.

From the examples of applications it is clear that the radioactive waste solution fed to BE contains a total of / 48 t H ^ BO ^ + 6.8 t NaNO ^ + + 8 t NaOH / 62.8 t salt which, without processing according to the invention, is a radioactive waste. should be embedded in a solid matrix / cement and stored under special conditions in an isotope cemetery.

In contrast, the radioactive product stream R / 0.912 t precipitate + 2 t ion exchanger / only 2.92 t, i.e. the mass of radioactive waste was reduced to 4.65% / m / m /.

With the BO pure boric acid stream, 37.2 tons of boric acid is recycled from the waste stream to provide a pure condensate / 36000-500-1360 / about 3415 .mu.m.

• · · · · · · · · · · · · · ·

- Eg = 21 2 ^{+ L} 5 á ^ram nitrate / no radioactive / industrial sóhulladékot / 10.8 t mainly BO ^ H ^ + ^ + NaNO 28.1 NaOH 1.1 t /, this salt is approximately 40 t much cheaper and easier to handle than radioactive, environmentally hazardous waste.

Claims (6)

It is desirable to concentrate the diluted waste solution collected in the receiving vessel to a concentration of up to 50, preferably 10-15 kg boric acid / m, and concentrate the resulting concentrate. - collecting 25 threaded storage tanks (3), while collecting the resulting condensate (KO / via cation and anion exchange columns (17, 18) and control vessel (19)) partly in the process as dilution water / TK, TK ^, TK ₂ /, condensate / E ^ / is recovered or recycled above the allowable activity level to the receiving container / REC-1 /. A process for the processing of a low and intermediate level nuclear radioactive waste solution by chemical precipitation, filtration, selective reverse osmosis separation and ion exchange of the soluble salt, characterized in that a precipitate of up to 50 kg / m 2 subjecting it to filtration and, after adjusting the pH, separating it into a boric acid and a nitrate stream in a boric acid / nitrate selective reverse osmosis separator; separating residual radioactive and nitrate contamination of the boric acid stream in an ion exchanger and draining the pure boric acid stream; decomposing the nitrate stream into a radioactive stream and a purified nitrate stream in a reverse osmosis separator selective for divalent and polyvalent ions; returning the radioactive stream to chemical attack; the remaining radioactive contamination of the purified nitrate stream is separated off in an ion exchanger and the pure nitrate stream is discharged, Method according to claim 1, characterized in that the concentrate (IU) obtained by evaporation of the waste solution (BE) is collected in a transitional collection container with the recycled radioactive streams (REC-2, REC-3), in a reactor vessel / 4 / by chemical addition in a specific order and concentration range of pH = 7-9 / Vp Vg ··· chemical precipitation, air homogenization and oxidation, coagulation, sedimentation and decantation / 5 /, ···· - pass through 23 hydrogen-form cation exchangers / 6 / in a partial stream / S _Q / and combine with the remaining partial stream / BP / to pH 4-5 and filter through a microfilter (7), then the product stream is / B / boric / nitrate selective and decomposing it into a boron acid stream (P - ^) and a nitrate stream (K - ^) in a one or two stage reverse osmosis separator (8); separating residual radioactive and nitrate contamination of the boric acid stream in cation and anion exchangers (9, 10) and removing the pure boric acid stream (BO); after temporary storage, the nitrate stream is adjusted to pH 4-5 by addition of alkali / lg / and diluted to a maximum of 15 kg / nr, then in a reverse osmosis separator selective for divalent and polyvalent ions (12) per radioactive stream (Kg) and a purified nitrate current (Pg) decomposed; combining the radioactive stream with the concentrate after temporary storage (REC-3); residual radioactive contamination of the purified nitrate stream in the inorganic ion exchanger characterized by the formula KgMe / Pe / CN / g7 selective for Cs ⁺ and Ag ⁺ ions (13) and after adjusting to ^ jpH = 8/1 ^ / in the complexing ion exchanger for divalent or polyvalent cations (14); and discharging the pure nitrate stream into a control tank (15) after collection and control as industrial waste (Eg) or combining it with the concentrate above the permissible level of activity (REC-2). Process according to claims 1 and 2, characterized in that the reactor vessel (4) is treated with the radioactive concentrate in the following manner with stirring, oxidation and coagulation with an air flow rate of 1-5 air / solution per hour: · · · · · · · · · · · · · · · Adjusting the pH to 7-9, preferably about 8, by adding Ing or acid, preferably NaOH or HNO 4; decontamination of the concentrate and construction of the colloidal compound by addition of precipitating chemicals and other chemicals in a given sequence and specific dosage: 1-4. in the order K _x Me _y / Fe / CN / g7 O-2000, preferably 70 mmol / m, where x = 0-2, y = 1-2; Fe (OH) 0-200, preferably 70 mmol / m 2; BaSO ^ 0-1000, preferably 200 mM; MnO / 0H / _z 200-4000, preferably 1100 mmol / m 2, where z = 1-2, on the one hand KMnO 2, on the other hand, reducing agent, preferably oxalic acid, citric acid, H 2 O 2 4. Process according to claims 1 to 3, characterized in that the hydrogen and hydroxide cationic anion exchange columns are regenerated by the addition of (6, 9, 10) acid and alkali (S, S, S, L), preferably countercurrent, and the regeneration solutions thus obtained / R ^, combined with the nitrate stream / K i / N / N, while the spent selective ion exchange column packing / ICS-1, ICS-2 / radioactive waste / R / is treated. 5. The method of claims 1 to 5, wherein 5, respectively, at a concentration of H2O2 of 0 to 10000, preferably of 2000 mmol / m, and of a nonionic polyelectrolyte of 0 to 50, preferably of 3 g / m 2; the air was then stopped to allow the precipitate to settle. 6. Equipment for processing low- and intermediate-level nuclear power plant waste solution from a reactor vessel, storage, filter, reverse osmosis separator and ion exchange unit, characterized in that it is connected to the receiving solution tank (1) / evaporator / 2 / which is partly a storage tank, and connected via an anion exchanger (17, 18) to a control vessel (19); a reactor vessel (4), a filter (5), a pH-adjusting ion exchanger (6), a microfilter (7) and a reverse osmosis separation unit (8) are connected to the storage vessel; the reverse osmosis separation unit coupled to a cation and anion exchange unit (9, 10) on the one hand and a temporary storage container (11) and a second reverse osmosis separation unit (12) on the other; the second reverse osmotic separation unit being connected to a selective ion exchanger (13), a complexing ion exchanger (14) and a second control vessel (15), and to a second temporary storage vessel (16) connected to the storage vessel (3).