阅读说明：本技术 一种评估核电厂事故后化学效应的台架试验系统及方法 (Bench test system and method for evaluating chemical effect of nuclear power plant after accident ) 是由 陈志刚 鲍一晨 苏豪展 石秀强 张乐福 刘晓强 程怀远 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种评估核电厂事故后化学效应的台架试验系统及方法,涉及核电安全评估领域,包括：溶解反应系统；设置于所述溶解反应系统内的若干反应罐；所述反应罐的罐体为不锈钢；所述不锈钢罐体的上方设置有五个贯穿件；所述五个贯穿件为热电偶、电导液位计、注液口、取样口、压力管道接口；还包括：通过所述注液口与所述反应罐连接的进样系统；通过所述取样口与所述反应罐连接的取样系统；与所述反应罐连接的沉淀系统；可对所述溶解反应系统和所述取样系统进行控制的控制系统。借助本发明所提供的系统及方法可获得事故后安全壳内材料在特殊水化学条件下的溶解和沉淀的试验数据。(The invention discloses a bench test system and a method for evaluating chemical effects of a nuclear power plant after an accident, which relate to the field of nuclear power safety evaluation and comprise the following steps: a dissolution reaction system; a plurality of reaction tanks arranged in the dissolution reaction system; the tank body of the reaction tank is made of stainless steel; five penetrating pieces are arranged above the stainless steel tank body; the five penetrating pieces are a thermocouple, a conductivity liquid level meter, a liquid injection port, a sampling port and a pressure pipeline interface; further comprising: the sample injection system is connected with the reaction tank through the liquid injection port; the sampling system is connected with the reaction tank through the sampling port; a sedimentation system connected to the reaction tank; a control system capable of controlling the dissolution reaction system and the sampling system. By means of the system and the method provided by the invention, test data of dissolution and precipitation of the material in the containment vessel under special water chemical conditions after an accident can be obtained.)

1. A bench test system for assessing post-accident chemical effects of a nuclear power plant, comprising:

a dissolution reaction system;

a plurality of reaction tanks arranged in the dissolution reaction system;

the tank body of the reaction tank is made of stainless steel;

five penetrating pieces are arranged above the stainless steel tank body;

the five penetrating pieces are a thermocouple, a conductivity liquid level meter, a liquid injection port, a sampling port and a pressure pipeline interface;

further comprising:

the sample injection system is connected with the reaction tank through the liquid injection port;

the sampling system is connected with the reaction tank through the sampling port;

a sedimentation system connected to the reaction tank;

a control system capable of controlling the dissolution reaction system and the sampling system.

2. The bench test system for assessing chemical effects after a nuclear power plant accident of claim 1, wherein the reaction tank is jacketed with a heating belt through which temperature control of the reaction tank is achieved.

3. The bench test system for assessing chemical effects of a nuclear power plant post-accident as recited in claim 1, wherein an open polytetrafluoroethylene inner tank is attached to an interior of said reaction tank.

4. The bench test system for assessing post-nuclear power plant accident chemical effects of claim 1, wherein the reaction tank further comprises: the reaction tank comprises reaction tank fixing clamping plates, reaction tank cover plates, O-shaped vacuum rubber sealing rings, connecting nut blocks, bolt sleeves, equal-length studs and I-shaped hexagon nuts.

5. The bench test system for assessing post-nuclear power plant accident chemical effects of claim 1, wherein the dissolution reaction system further comprises: the device comprises a fixed seat, a motor, an eccentric hub, a connecting rod, a connecting shaft, a check ring, a threaded push rod, a tray connecting block, a reaction tank carriage, a cast aluminum heating plate, a heat insulation wood plate and ceramic fiber cotton.

6. The bench test system for assessing chemical effects after a nuclear power plant accident of claim 1, wherein the sample injection system is provided with a plurality of sets of water tanks, each set of water tanks comprising a plurality of water tanks; the water tank is provided with a heater; the water tank is connected with the liquid injection port through a water separator and a water supply electromagnetic valve.

7. The bench test system for assessing chemical effects after a nuclear power plant accident of claim 1, wherein the sampling system is connected to the sampling port via a sampling solenoid valve and a peristaltic pump; the sampling system is connected with the PLC console of the control system and samples at a preset sampling time point.

8. The bench test system for assessing chemical effects after a nuclear power plant accident of claim 7, wherein the precipitation system comprises a plurality of precipitation reaction cones, and wherein the solution in the reaction tank is pumped into the precipitation reaction cones for precipitation through a loop outlet line and the peristaltic pump.

9. The bench test system for assessing chemical effects after a nuclear power plant accident of claim 8, wherein the loop outlet line uses 1/8 tubing; and the outlet pipeline of the loop is soaked in a constant-temperature water bath environment at 60 ℃.

10. An evaluation method of a bench test system for evaluating a chemical effect after a nuclear power plant accident based on any one of claims 1 to 9, the method comprising the steps of:

step one, putting a material to be detected into the dissolution reaction system;

step two, respectively adding a boric acid solution with pH4, a sodium hydroxide solution with pH 8 and a sodium hydroxide solution with pH 12 into the dissolution reaction system through the sample injection system;

step three, enabling the reaction temperature in the dissolution reaction system to be adjustable between 25 ℃ and 200 ℃ through the control system and simultaneously carrying out dissolution reaction;

step four, periodically sampling the solution in the dissolution reaction system through the sampling system and analyzing the chemical composition of the solution to obtain a dissolution release curve of the element in the material to be detected;

step five, after the dissolution reaction in the step three is finished, introducing the solution into the precipitation system, and respectively carrying out water-cooling precipitation, trisodium phosphate regulation precipitation, sodium hydroxide precipitation and mixed precipitation among different dissolution material solutions;

taking out the dissolved material to be detected, analyzing the change of the quality and obtaining a dissolution rate curve;

and step seven, analyzing the chemical composition of the precipitate and evaluating the interaction effect between the chemicals after the accident.

Technical Field

The invention relates to the field of nuclear power safety assessment, in particular to a bench test system and method for assessing chemical effects of a nuclear power plant after an accident.

Background

A nuclear power station containment pit is an important component of a pressurized water reactor nuclear power station safety injection system and a Containment Spray System (CSS). The containment pit is used for collecting liquid released by a safety injection system and a containment spraying system when a loss of coolant accident (LOCA) occurs, and providing a standby cooling water source for special safety facilities when a refueling water tank is used up.

The containment pit is provided with a filter screen for filtering various fragments and sundries which flow into the pit along with scouring and falling after a serious accident. After the LOCA accident occurs, a large number of electrical components, auxiliary equipment and the like in the containment vessel are soaked and leached by coolant, spray liquid and buffering agent in the accident to generate various chemical reactions, so that chemical fragments are formed. On the one hand, the chemical fragments of large particles cover on the filter screen, increase the head loss of pit filter screen, influence the recirculation function of pit to influence the long-term cooling of reactor core. On the other hand, small-particle chemical fragments enter a primary coolant through a circulating pump, so that the operation safety of the reactor is affected.

Chinese patent CN 104934081B reports a method for evaluating chemical effects after an accident in a pressurized water reactor nuclear power plant, which uses a theoretical model to theoretically calculate the type and yield of chemical precipitates after the accident in the pressurized water reactor nuclear power plant, and provides a theoretical evaluation basis for the performance of a pit filter, the reliability of the recirculation function of an emergency reactor cooling system and a containment vessel spraying system. Chinese patent CN 108361375B reports a visual segmented sealing cylinder used for chemical effect research of nuclear power plants, and the cylinder can be used for observing test phenomena at the front end and the rear end of a pit filter screen.

However, the test data of the dissolution and precipitation of the materials in the containment under special water chemical conditions after accidents still lack in China. How to design a test system and analyze the chemical reaction of dissolution and deposition after an accident through test data is an urgent problem to be solved.

Therefore, those skilled in the art are dedicated to develop a bench test system and method for evaluating chemical effects of a nuclear power plant after an accident, and the problem of test data loss of dissolution and precipitation of a material in a containment vessel under a special water chemical condition after the accident in the prior art is solved.

Disclosure of Invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to obtain reliable test data to evaluate the dissolution and precipitation performance of electrical components and auxiliary equipment in a containment vessel under a simulated containment accident environment.

To achieve the above object, the present invention provides a bench test system for evaluating chemical effects after a nuclear power plant accident, comprising:

a dissolution reaction system;

a plurality of reaction tanks arranged in the dissolution reaction system;

the tank body of the reaction tank is made of stainless steel;

five penetrating pieces are arranged above the stainless steel tank body;

the five penetrating pieces are a thermocouple, a conductivity liquid level meter, a liquid injection port, a sampling port and a pressure pipeline interface;

further comprising:

the sample injection system is connected with the reaction tank through the liquid injection port;

the sampling system is connected with the reaction tank through the sampling port;

a sedimentation system connected to the reaction tank;

a control system capable of controlling the dissolution reaction system and the sampling system.

Furthermore, a layer of heating belt is sleeved outside the reaction tank, and the temperature of the reaction tank is controllable through the heating belt.

Furthermore, an opening polytetrafluoroethylene inner tank is attached to the inner part of the reaction tank.

Further, the reaction tank further comprises: the reaction tank comprises reaction tank fixing clamping plates, reaction tank cover plates, O-shaped vacuum rubber sealing rings, connecting nut blocks, bolt sleeves, equal-length studs and I-shaped hexagon nuts.

Further, the dissolution reaction system further comprises: the device comprises a fixed seat, a motor, an eccentric hub, a connecting rod, a connecting shaft, a check ring, a threaded push rod, a tray connecting block, a reaction tank carriage, a cast aluminum heating plate, a heat insulation wood plate and ceramic fiber cotton.

Furthermore, the sample introduction system is provided with a plurality of groups of water tanks, and each group of water tanks comprises a plurality of water tanks; the water tank is provided with a heater; the water tank is connected with the liquid injection port through a water separator and a water supply electromagnetic valve.

Further, the sampling system is connected with the sampling port through a sampling electromagnetic valve and a peristaltic pump; the sampling system is connected with the PLC console of the control system and samples at a preset sampling time point.

Further, the precipitation system comprises a plurality of precipitation reaction cones, and the solution in the reaction tank is pumped into the precipitation reaction cones through a loop outlet pipeline and the peristaltic pump for precipitation.

Further, the loop outlet line uses 1/8 tubing; and the outlet pipeline of the loop is soaked in a constant-temperature water bath environment at 60 ℃.

The invention also provides an evaluation method of the bench test system for evaluating the chemical effect of the nuclear power plant after the accident based on any one of the items 1 to 9, which comprises the following steps:

step one, putting a material to be detected into the dissolution reaction system;

step two, respectively adding a boric acid solution with pH4, a sodium hydroxide solution with pH 8 and a sodium hydroxide solution with pH 12 into the dissolution reaction system through the sample injection system;

step three, enabling the reaction temperature in the dissolution reaction system to be adjustable between 25 ℃ and 200 ℃ through the control system and simultaneously carrying out dissolution reaction;

step four, periodically sampling the solution in the dissolution reaction system through the sampling system and analyzing the chemical composition of the solution to obtain a dissolution release curve of the element in the material to be detected;

step five, after the dissolution reaction in the step three is finished, introducing the solution into the precipitation system, and respectively carrying out water-cooling precipitation, trisodium phosphate regulation precipitation, sodium hydroxide precipitation and mixed precipitation among different dissolution material solutions;

taking out the dissolved material to be detected, analyzing the change of the quality and obtaining a dissolution rate curve;

and step seven, analyzing the chemical composition of the precipitate and evaluating the interaction effect between the chemicals after the accident.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

1. by providing a set of bench test system capable of simulating chemical effects of post-accident containment pit of a nuclear power plant and an analysis method of dissolution and precipitation performance of post-accident containment materials, dissolution and release behaviors of the post-accident containment materials in boric acid solution with pH4 at different temperatures (25-200 degrees C) of the post-accident containment pit early-stage materials in the nuclear power plant can be simulated, and dissolution and release behaviors of the materials sprayed by a spraying system (with pH 8 and pH 12) at different temperatures (25-200 degrees C) can be simulated, so that test data of dissolution of post-accident containment materials under special water chemistry conditions can be obtained.

2. The experimental data of the precipitation of the materials in the containment under special hydrochemical conditions after an accident are obtained by partly simulating different precipitation behaviors in the system precipitation reaction, such as natural cooling precipitation behaviors (pH 4, 8 and 12) of a solute under a single working condition, cooling precipitation behaviors (precipitation of a solution with pH4 and pH 12/pH 8 mixed together) under a complex working condition, and precipitation behaviors after triggering a safe shell TSP (trisodium phosphate) adjusting basket (TSP adjusts the pH of the precipitation solution to 7-8).

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is an assembly view of a preferred embodiment of the present invention;

FIG. 2 is a schematic view of the embodiment shown in FIG. 1;

FIG. 3 is a schematic diagram of the embodiment shown in FIG. 1;

FIG. 4 is a pictorial representation of the embodiment of FIG. 1;

FIG. 5 is a schematic diagram of a reaction tank according to a preferred embodiment of the present invention;

FIG. 6 is a schematic view of a dissolution reaction system of the embodiment shown in FIG. 5;

FIG. 7 is a schematic view of a precipitation system according to a preferred embodiment of the present invention;

fig. 8 is a dissolution release profile of carbon steel at 75 ℃ in boric acid solution at pH 4;

FIG. 9 is a water-cooled precipitation diagram of carbon steel extract at pH 4;

FIG. 10 is a graph showing the precipitation of carbon steel eluate after pH adjustment by TSP;

FIG. 11 is a graph of the precipitation of carbon steel eluate at pH4 mixed with boron-containing silicone resin eluate at pH 12.

Wherein, 1-a dissolution reaction system, 1001-a reaction tank fixing splint, 1002-a reaction tank cover plate, 1003-O type vacuum rubber sealing ring, 1004-a connecting nut block, 1005-a bolt sleeve, 1006-equal length stud, 1007-I type hexagon nut, 1008-a reaction tank, 1009-a reaction tank inner container, 1010-a fixing seat, 1011-a motor, 1012-an eccentric hub, 1013-a connecting rod, 1014-a connecting shaft, 1015-a retainer ring, 1016-a threaded push rod, 1017-a tray connecting block, 1018-a triangle fixing block, 1019-a reaction tank dragging plate, 1020-a cast aluminum heating plate, 1021-a fixing track, 1022-a heat insulation wood plate, 1023-ceramic fiber cotton, 2-a system bracket and an automatic feeding/sampling system, 3-a precipitation system, 3001-water bath water tank, 3002-precipitation reaction cone, 3003-reaction precipitation cone fixing support, 3004-40X 240 section bar, 3005-40X 40 corner fitting, 3006-40X 80X 800 section bar, 3007-ground support, 3008-40X 1640 section bar, 3009-40X 1120 section bar and 4 control system.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.