Preliminary study on inversion model of radioactive release source terms

Objective Based on the monitoring data, Gaussian plume model and optimization algorithm, the inversion model of radioactive release source term was preliminarily studied. Methods By comparing the application conditions and performance of several optimization algorithms, the accuracy of source term inversion results of different algorithms under the same conditions was compared and verified. Results The preliminary study of radioactive release source term inversion model shows that it is feasible to use the least square method to optimize the inversion model based on Gaussian plume. The accuracy of the optimized model is 0.92 times of the measured value for flat terrain, and 1.5 times of the measured value for complex terrain, whose error is relatively large because of the limitation of the model itself. Conclusion The results show that the optimized source term inversion model based on Gaussian plume and least square method can better meet the needs of nuclear accident consequence assessment and emergency decision-making in terms of computational performance and accuracy. 摘要： 目的 基于监测数据、高斯烟羽模型和优化算法, 初步研宄放射性释放源项反演模型。 方法 通过比较几种优 化算法的适用条件和性能, 并对相同条件下不同算法源项反演计算结果的准确性进行比较验证。 结果 通过对放射 性释放源项反演模型初步研宄, 发现基于高斯烟羽的反演模型, 采用最小二乘法优化后进行释放源项反演计算是可行 的。该优化模型对于简单地形下的模拟结果精度较高, 为实测值的 0.92 倍; 对于复杂地形条件下的模拟结果受模型本 身限制误差相对较大, 为实测值 1.5 倍。 结论 研宄表明高斯烟羽结合最小二乘法的优化源项反演模型在计算性能和 精度上可更好地满足核事故后果评价和应急决策需求。