堆芯损伤评价中安全壳内放射性核素浓度的计算

Calculation of Containment Radionuclide Concentration in Core Damage Assessment

安全壳内放射性核素浓度的计算是确定安全壳辐射剂量率的重要环节,而安全壳辐射剂量率是堆芯损伤评价的重要参数之一。本文利用ORIGEN2程序,采用简化分析法和间接计算法分别对事故后3种典型核素在安全壳内的浓度进行分析计算,并对两种方法的可用性进行了讨论。根据分析可知,间接计算法能够更好的模拟核素的释放、衰变以及相互转化过程,建议在事故早期堆芯损伤评价过程中使用。但是若考虑事故发生较长时间后的安全壳内核素浓度,短半衰期核素影响已经很小,简化分析法是可用的。

Calculation of containment radionuclide concentration is an important part of estimating containment radiation dose rate ,and the latter is a primary parameter for core damage assessment .This paper provides the calculation of concentration of three typical nuclides within containment post-accident in both simplified analyt-ical method and indirect method with ORIGEN 2 code .The results show that the indirect method can simulate the release and decay of radionuclides and the transformation among them ,and suggests it can be used in the early core damage assessment .But if the containment radionuclide concentration is evaluated after a long time since the accident ,when the nuclides with short half-lives have little effects on the result ,the simplified meth-od is appropriate .