RESEARCH ON ROBOTS AND INTELLIGENT EQUIPMENT IN NUCLEAR INDUSTRY

RESEARCH ON ROBOTS AND INTELLIGENT EQUIPMENT IN NUCLEAR INDUSTRY

Dou Xiangping

Master, St. Petersburg State Electrotechnical University,

Russia, St. Petersburg

ABSTRACT

With the acceleration of my country's industrial structure adjustment, transformation and upgrading, it has greatly driven the demand of my country's intelligent equipment industry market represented by robots and the rapid development of the industry, and has become an important symbol of scientific and technological innovation in the new era. As a high-tech strategic industry, the nuclear industry is inseparable from the support of robotics and intelligent equipment in all aspects of the industrial chain.

Keywords: spent fuel processing technology and related equipment, PUREX technology, nuclear industry equipment.

Introduction:

In the field of nuclear industry applications, due to the radioactive nature of the equipment itself or its operating environment, there are certain safety risks or limited operations in personnel operations, and the use of robots for equipment maintenance, radioactive waste treatment, emergency response, etc. Due to the cost and management cost of artificial protective equipment, on the other hand, it reduces the radiation dose and labor intensity of the staff. With the continuous expansion of the installed capacity of nuclear power plants, the demand for robot applications will become increasingly urgent.

Purpose of spent fuel processing:

Under the background of "carbon neutrality", nuclear power will become an important part of future baseload energy by virtue of its advantages of high energy efficiency, low pollution, large unit capacity, and stable power generation. The nuclear fuel cycle is a link that cannot be ignored in the development of nuclear power. Under the background of increasing installed capacity, how to deal with the increasing amount of nuclear power spent fuel and ensure the safe and stable operation of the industrial system is an urgent problem to be solved in the current nuclear power development.

The main purpose of spent fuel processing is to improve resource utilization and reduce the threat to the environment, which is closely related to the composition of spent fuel. Spent fuel is mainly composed of uranium, plutonium, and their fission products. The closed cycle of spent fuel can improve the utilization rate of uranium and plutonium. Spent fuel reprocessing can reduce the threat to the link. After spent fuel reprocessing, the volume of high-level radioactive waste will be reduced to a quarter of its original volume, and its long-term radiotoxicity will be reduced by more than an order of magnitude.

Spent fuel treatment process and related equipment:

There are two main ways of disposing of spent fuel in countries operating nuclear power in the world. One is the open fuel cycle route: after simple shearing and packaging, it is transported to a suitable location and buried directly; the other is the closed fuel cycle, that is, the uranium, plutonium and other elements in the spent fuel are separated for reuse. , reduce its activity and radioactivity, and landfill high-level radioactive waste. At present, France, Russia and China have adopted this technical route.

1.Store in heap

There is also a temporary disposal method, which is temporary storage in the reactor, before final landfilling. Generally, nuclear power plants are equipped with spent fuel storage pools, which are used to temporarily store the spent fuel unloaded from the core, and the new fuel to be loaded during refueling is also temporarily stored in it. Generally, the service life of a nuclear power plant is 40-60 years, and the design capacity of the in-reactor storage pool is 10-20 years of spent fuel discharge. deal with.

2. PUREX technology and equipment

PUREX is currently the mainstream technology route for spent fuel reprocessing. The spent fuel reprocessing plant has high technical difficulty, and the processing technology can be divided into dry method and wet method. Among them, using tributyl phosphate (TBP) as the extractant is the most mature mainstream technology at present.

Spent fuel reprocessing can be divided into head-end treatment, extraction separation and tail-end treatment according to the procedures.

a) The main supply and demand of head-end treatment includes the cutting of spent fuel assemblies, decladding, fuel pellet dissolution, filtration, seasoning, and exhaust gas treatment.

b) The purpose of the extraction and separation process is mainly to separate and purify uranium, plutonium and radioactive fission products.

c) The uranium and plutonium intermediate products obtained by solvent extraction, separation and purification cannot meet the application requirements in terms of purity and form. Therefore, after the extraction and purification of the main body of uranium and plutonium, purification is still required to further remove impurities in plutonium and convert it into metal plutonium or stable compounds. A complete set of process steps from uranium or plutonium intermediates for supplementary purification, enrichment and conversion to final product form is called tail end treatment.

Summarize:

In general, some technologies are mature and ready for commercial use, such as neutron absorption materials and conventional mechanical and electrical equipment. Some products need to be adaptively developed or improved on the basis of existing nuclear power, such as remote-operated valves, manipulators, hot cells, etc. However, the main equipment of the process flow of PUREX technology is technically difficult. For example, shears, dissolution reactors, centrifugal clarifiers, pulse filters, extractive separators, vitrification units, and the like.

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