铀、钚浓度是乏燃料后处理工艺控制分析的关键参数，研究铀、钚样品分析方法对Purex流程工艺控制安全和改善至关重要。本项目拟采用高能量分辨率透射谱获取技术和信号反卷积分析方法、样品试验和MCNP建模相结合的研究手段，对铀、钚样品L边界分析方法开展系统深入地研究。首先，研发适用于高计数率环境和高浓度样品的透射谱获取系统，研究透射谱能量沉积特征，确定最优滤波成形算法及最佳达峰时间参数。其次，采用模拟、实际样品试验和MCNP建模，揭示测量系统特征参数对L边界分析方法的影响规律，建立测量准确度、精密度及检出限影响因子数学模型。最后，利用能量外推和归一化参考谱，提出高/低原子序数基体校正方法；确定透射谱本底来源，建立透射谱本底数学模型。结合Purex流程中铀、钚样品应用分析，建立铀、钚样品L边界分析方法，为乏燃料后处理工艺控制分析提供有力的技术支撑和保障。

The concentrations of uranium and plutonium are significant parameters in process control and analysis of spent fuel reprocessing. Thus, study on the analysis methods of uranium and plutonium concentrations are curial for process control safety and improvement of the Purex process. Several research methods, including transmission spectrum detection technique, signal deconvolution analysis, experimental tests and MCNP modeling, are adopted to study the L-edge analysis method systematically. Firstly, a detection system, which is capable of high counting-rate situation and high concentration sample, is developed for transmission spectrum acquisition. The optimal pulse shaping algorithm and peaking time parameter of the system are obtained by studying the energy deposition characteristics of the transmission spectrum. Then, surrogate / actual samples tests and MCNP modeling are carried out to reveal the influence of the characteristic parameters of the measurement system on the L-edge analysis method. And the influence law of the system parameters is used to make mathematical models of performance indicators, including accuracy, precision and detection limits, and their factors. Finally, extrapolation and normalization to reference spectrum are applied for matrix correction of both high z number and low z number materials. And the background mathematical model is also built by analyzing the background sources. Based on the analysis of actual samples of the Purex process, the system of the L-edge analysis method of uranium and plutonium samples is established. It can provide powerful technical support and guarantee to process control and analysis of spent fuel reprocessing.