Analysis And Improvement On Usual Fault Of Demineralized Water System Of Tianwan Nuclear Power Station

According to the current state of the energy structure and development planning, nuclear energy will be an important source of energy in the future. But after Japan’s fukushima nuclear accident in March 2011, how to guarantee the safe and stable operation of nuclear power plant and nuclear power development of China’s energy medium to long term planning is of vital significance. In addition to the demineralized water system as an important system of nuclear power plant operation, is a power plant, startup and operation of RCS and the secondary circuit. With the enlargement of the scale of production, now is becoming more and more strict to the requirement of water quality. In addition to the demineralized water system as an important chemical water treatment system, the running stability and reliability for the safety in production is more and more important.Analysis and discussion on the functions, composition and operating principles of the demineralized water systemof Tianwan Nuclear Power Station. In the process of the operation of the system, along with the water inlet water quality deterioration and equipment aging problems, such as system appeared some common fault, initial design flaws, such as cation bed ion exchange frequent fault and other issues. At the same time, due to the particularity of TNPS use the Russian technology, some initial design in production run in the future also exposed many shortcomings. This chapter, the construction of TNPS unit 1 and 2, in addition to the common faults of demineralized water system are analyzed, and find out the cause of the problem, and the corresponding technical improvement.Make-up water desalination technology adopted by the cation exchanger of countercurrent regeneration cation exchanger, for this kind of countercurrent regeneration of resin bed, born again need to use 180 tons/hour traffic from the bottom of the resin on the compaction, and into the regeneration of resin bed regeneration, the resin is by disturbance phenomenon at this time. In order to thoroughly solve the problem of disturbance of resin regeneration, improve the reliability of system operation, further energy conservation and emissions reduction, transformed cation bed into elastic full chamber fixed bed countercurrent regeneration ion exchanger. Due to frequent ion exchanger failure, in addition to the system often shutdown overhaul by ion exchanger failure, seriously affected the reliability of the system, at the same time because maintenance repeatedly regeneration and flush the filter also caused many unnecessary economic loss, through research and analysis to find out for ion exchanger water cap material unqualified cause, therefore, will be the overall water cap to replace. Through production practice and the standard peer units, found that acid dosing pump is not available in the system time on the high side, thus find out the cause of the problem lies in the pipeline resistance and export electric valve fault, after the implementation of the relevant modification to solve the problem.Pointed out the common fault during the time of unit construction, commissioning and manufacturing operations, put forward the corresponding solutions, and implemented a series of improvements to ensure the safe and stable operation of the system, to enhance the economic and environmental benefits.