CAJ | 학술논문

严重事故下熔融物与下封头间球形窄缝通道的存在对于下封头结构的完整性有一定的积极意义。本工作通过理论分析，在汽液两相间逆向对流限制机理的基础上提出了球形窄缝通道内的CHF机理模型和预测关系式，预测结果与实验数据符合较好，验证了所建模型的正确性，并进一步分析了系统压力、熔融物半径、间隙尺寸等关键参数对临界热流密度的影响规律。利用本工作的预测模型对三哩岛（TMI-2）事故后堆芯熔融物特性进行了计算分析，结果表明，熔融物与下封头内壁面间的球形窄缝可有效带走堆芯余热，保证了下封头的完整性。
엄중사고하용융물여하봉두간구형착봉통도적존재대우하봉두결구적완정성유일정적적겁의의。본공작통과이론분석，재기액량상간역향대류한제궤리적기출상제출료구형착봉통도내적CHF궤리모형화예측관계식，예측결과여실험수거부합교호，험증료소건모형적정학성，병진일보분석료계통압력、용융물반경、간극척촌등관건삼수대림계열류밀도적영향규률。이용본공작적예측모형대삼리도（TMI-2）사고후퇴심용융물특성진행료계산분석，결과표명，용융물여하봉두내벽면간적구형착봉가유효대주퇴심여열，보증료하봉두적완정성。
The existence of the hemispherical narrow gap between the molten corium and the lower head during severe accidents is very significative to the integrity of the lower head .Based on the counter current flow limitation between the vapour phase and liquid phase ,a mechanism model and a predicting formula of CHF in hemispherical narrow gap were proposed .The established model was validated by comparing the predicted results with the test data ,which showed good agreement between them .Furthermore ,the effects of key parameters including the system pressure ,the radius of molten corium and the gap size on the critical heat flux were also analyzed .Besides ,the accident of TMI-2 was also calculated by using the predicting formula .The results indicate that the narrow gap between the molten corium and the lower head can take away the afterheat of the reactor core effectively and ensure the integrity of the lower head .