Comprehensive Performance Verification Method for Evaporators in Nuclear Power Plants

Abstract

The invention provides a comprehensive performance verification method for a nuclear power station evaporator, and the method comprises the following steps: additionally installing a distillate reuse branch pipe, connected with a material incoming pipeline of a return evaporator, on a distillate drainage pipe of the evaporator, and preparing boron-containing test material solution with proper concentration; starting the evaporator, and enabling the test material solution with the boron concentration being not less than the maximum boron concentration of a reactor core at the beginning of the lifetime to be serve as incoming material solution. During testing, distillate cannot be discharge outwards, and is returned to the material incoming pipeline to serve as incoming material solution for reuse, thereby enabling the boron concentration of the incoming material solution to be reduced continuously, simulating the process of evaporation, separation and decontamination of waste liquid which is discharged in the lifetime of a nuclear power station and has different boron concentrations, and taking a condition that the boron concentration of distillate and the distillate of concentrated solution reach a standard value as an acceptance index of qualified testing. Compared with the prior art, the method simulates the demands of separation and decontamination of boron-containing radioactive waste liquid in the lifetime of the nuclear power station, so the qualified evaporator can operate at the nuclear power station stably for a long time.

Description

technical field [0001] The invention belongs to the field of performance verification of evaporation devices of nuclear power plants. More specifically, the invention relates to a method for comprehensive performance verification of evaporation devices of nuclear power plants. Background technique [0002] Nuclear power plants will produce a large amount of boron-containing radioactive waste liquid during normal operation and under expected accident conditions. If all these waste liquids are directly discharged into the environment, it will bring great radiation hazards to the environment, and excessive boric acid will be released into the environment. It can also affect the health of animals and plants. The evaporation device is a device that uses evaporation technology to treat boron-containing radioactive waste liquid. It sends the waste liquid to the heater through natural circulation or forced circulation to raise the temperature, and then enters the evaporation tower f...

AI Technical Summary

Problems solved by technology

[0005] 1) Insufficient representativeness: The boron concentration of the boron-containing radioactive waste liquid discharged from the nuclear power plant is different under different reactor lifetimes. The current verification method can only perform evaporation separation simulation on the waste liquid with a fixed boron concentration, and cannot verify the evaporation device. For the evaporation separation and decontamination effect of waste liquids with different boron concentrations, there is a deviation between the verification process and the actual operating conditions of the evaporation device, so the representativeness is insufficient;

[0006] 2) Waste of resources: During the verification period, the processing capacity of the evaporation device of the nuclear power plant is about 3.5t / h, and the continuous operation stability test is carried out for a maximum of 100h, and the amount of desalinated water consumed is about 350t. The distillate obtained by evaporation during the verification process is directly discharged. caused a lot of waste;

[0007] 3) The verification is not comprehensive: The known test methods are insufficient in the content and depth of the comprehensive performance verification of the newly developed evaporation device, and have not verified other important factors that affect the comprehensive performance of the evaporation device, such as: the operating energy consumption of the evaporation device cannot be measured , no high boron concentration operation test, unable to test the optimum operating liquid level, etc.

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