放化分离-液闪测量联合分析核电厂废树脂中的^(55)Fe和^(63)Ni北大核心CSCD

建立了一种核电厂放射性废离子交换树脂中^(55)Fe和^(63)Ni的联合分析方法。将废树脂样品经芬顿氧化消解后,先用氢氧化钠沉淀法沉淀^(55)Fe和^(63)Ni,再用阴离子交换树脂联合丁二酮肟沉淀对杂质离子进行分离纯化,纯化后用液体闪烁计器测量。本方法对废树脂中^(60)Co、^(65)Zn、^(54)Mn等干扰核素的去污因子均大于10^(3)。本方法对^(55)Fe和^(63)Ni的平均化学回收率分别为86%和90%,对废树脂中^(55)Fe和^(63)Ni的检测限分别为5.7 Bq/g、6.8 Bq/g。用加标样品对分析方法进行验证,预期值和测量值的偏差小于±10%。实验测得某核电厂一组一回路实际废树脂样品中^(55)Fe和^(63)Ni的平均活度浓度分别为(76.2±1.4)kBq/g和(120.0±5.1)kBq/g。

Determination of 55Fe and 63Ni in spent resin of nuclear power plant using radiochemical separation and liquid scintillation counting

In this work, a method for sequential determination of ⁵⁵Fe and ⁶³Ni in spent resins of nuclear power plants was developed. After decomposing the spent resin sample, ⁵⁵Fe and ⁶³Ni ions were first precipitated in the form of hydroxide and subsequently purified by anion exchange chromatography and dimethylglyoxime precipitation. After purification, ⁵⁵Fe and ⁶³Ni were determined by liquid scintillation counting (LSC). The average chemical recovery rate of ⁵⁵Fe and ⁶³Ni was 86% and 90% respectively. The decontamination factors of interfering radionuclides such as ⁶⁰Co, ⁶⁵Zn and ⁵⁴Mn by the sequential determination method were higher than 1 000. The deviation of expected and measured values was less than ±10% through the validation of the analytical method with spiked samples. The measured average activities of ⁵⁵Fe and ⁶³Ni in a set of spent resin samples from its primary loop of a nuclear power plant were (76.2±1.4) kBq/g and (120.0±5.1) kBq/g, respectively.