The operation data of PWR nuclear power plant show that after the unit implements large flow degassing operation,the specific activity of fission products of primary coolant oscillates violently in a short time,which makes the fuel damage prediction method based on the average core state fission release-to-birth ratio(R/B)have prediction bias.Based on the parameters of degassing system and the mechanism of inert gas release in PWR nuclear power plant,this paper establishes a modified prediction and analysis model of inert gas release in degassing operation,gives the calculation method of degassing factor and inert gas release rate under degassing conditions,and optimizes the traditional prediction method of fuel rod break size based on R/B.The modified prediction method of degassing operation has been applied and verified in a PWR nuclear power plant.The maximum relative deviation of specific activities of six common inert gas nuclides predicted is 33.4%,and the others are less than 20%.The predicted fuel rod break size is large,which is consistent with the inspection results after shutdown.
关键词
燃料棒破损/除气运行/裂变产物比活度/压水堆
Key words
Fuel rod failure/Degassing operation/Fission product activity/PWR
维普
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