Research On The Defect Evaluation Of Tianwan Nuclear Power Plant Reactor Pressure Vessel

The most serious incident in nuclear power plant of light-water reactor (PWR and boiling water reactor) may be the catastrophic breakdown of the reactor pressure vessel, which leads to the release and disclosure of a large quantity of radioactive. The staff, the public and the environment will be damaged seriously. Good and conservative design can protect the safty of nuclear power plants. But poor design or chaotic managment will bring the potential consequences of the accident, which will lead to serious disastrous consequences. Therefore, accurate assessment of defects of nuclear reactor pressure vessels in service is a very important subject.Tianwan Nuclear Power Plant belongs to Russian-based AES-91 pressurized water reactor nuclear power plant units. It is based on WWER-1000/V320 design, and designed by international regulations and the introduction of advanced technology and matural technology. Tianwan Nuclear Power Plant is a "turnkey" project. The overall technical responsibility for nuclear power plants belongs to Russian commitment. The transfer of technology is limited. China does not have a large number of detailed technical design information. In addition, because the specificity of the Russian standards, the formation of nuclear power standards is lagging. There is still a gap in some respects,such as the design and operated management of current international advanced nuclear power plant. By now, there has been no specific formulation of the Russian WWER nuclear power plant in service acceptance criteria for defects inspection standards. Tianwan in the current implementation of service standards is nHA3F-07-010-89 "nuclear power plant equipment and pipes welded joints and surfacing of the test order" manufacturing phase of the inspection and acceptance criteria. It is not economic not reality that if the same acceptance criteria out only used in the manufacture of nuclear equipment, but also used in-service inspection. Therefore, China must draw up the in-service inspection acceptance criteria of Tianwan Nuclear Power Plant for ourselves. The RPV is the key equipment of nuclear power plant. In this paper, the study focuses on the nuclear RPV.The purpose of this paper is giving a general evaluation methods suit for Tianwan NPP RPV defect analysis to provide technical basis for drawing up the acceptance criteria of Tianwan NPP RPV In-service inspection.The object of this paper is Tianwan NPP RPV. Based on the study and guidelines of Russian existing methods for the theoretical ,based on the theory of fracture mechanics, based on the project of "Drawing on the inspection acceptance criteria of Tianwan NPP in service", the paper carried out the following aspects of the study:(1)Prove the applicability of fracture toughness curve to Tianwan NPP RPV;(2)Prove the applicability of stress intensity factor to Tianwan NPP RPV;(3) Based on the conclusions of (1) and (2) ,it studies the pressure thermal shock for Tianwan NPP RPV 2 # weld .Through this analysis, the paper can provide a theoretical basis for giving suitable methods to evaluate the finding the defects in servive of Tianwan NPP RPV WWER1000 type.