Effect of kinetic model parameters on fission product (I-129) activity from fuel to coolant in PWRs has been studied in this work. First a computational model was developed for fission product release into primary coo...Effect of kinetic model parameters on fission product (I-129) activity from fuel to coolant in PWRs has been studied in this work. First a computational model was developed for fission product release into primary coolant using ORIGEN-2 as subroutine. The model is based on set of differential equations of kinetic model which includes fuel-to-gap release model, gap-to-coolant leakage model, and Booths diffusion model. A Matlab based computer program FPAPC (Fission Product Activity in Primary Coolant) was developed. Variations of I-129 activity in Primary Heat Transport System were computed and computed values of i-129 were found in good agreement and deviations were within 2% - 3% of already published data values. Finally, the effects of coolant purification rate, diffusion constant and gas escape rate on I-129 activity were studied and results indicated that the coolant purification rate is the most sensitive parameter for fission product activity in primary circuit. For changes of 5% in steps from −10% to +10% in the coolant purification rate constant (Β), the activity variation after 200 days of reactor operation was 23.1% for the change.展开更多
本研究建立了AMS(Accelerator mass spectrum,加速器质谱)测定海水中129 I的气载分离制样方法:对加入载体的海水样品进行氧化还原处理,在加热的条件下将生成的单质碘吹出,并使用吸收装置吸收,后经阴离子交换树脂富集纯化,最后生成用于AM...本研究建立了AMS(Accelerator mass spectrum,加速器质谱)测定海水中129 I的气载分离制样方法:对加入载体的海水样品进行氧化还原处理,在加热的条件下将生成的单质碘吹出,并使用吸收装置吸收,后经阴离子交换树脂富集纯化,最后生成用于AMS分析的AgI沉淀,本方法全程回收率50%~70%,在相对密闭的体系中进行,减少了碘的损失,相对于萃取-反萃取的制样方法具有可操作性强,避免有机试剂使用等优点,可用于固态、液态和气态样品中129 I的AMS分析制样。展开更多
中国辐射防护研究院(China Institute for Radiation Protection,CIRP)引进一台300 kV多核素低能加速器质谱仪(Multi-Isotope Low-Energy Accelerator mass spectrometry,MILEA),可用于各种基体样品中超低含量的^(14)C、^(129)I和锕系核...中国辐射防护研究院(China Institute for Radiation Protection,CIRP)引进一台300 kV多核素低能加速器质谱仪(Multi-Isotope Low-Energy Accelerator mass spectrometry,MILEA),可用于各种基体样品中超低含量的^(14)C、^(129)I和锕系核素(Pu同位素、^(237)Np、Am同位素、Cm同位素及U同位素)的测量。在对该系统进行现场验收及调试测量中,通过对稳定核素从低能端到高能端的传输效率及高能端的电流强度、空白样品中稀有放射性核素与其稳定核素的比值及丰度灵敏度、标准样品中单个样品及多个样品测量的弥散度等关键参数的测试,结果显示:^(14)C/^(12)C最小比值为(1.3±0.1)×10^(-15),测量精度为0.2%;WWI^(129)I/127I最小比值为(3.76±0.2)×10^(-14),测量^(129)I/127I比值为10-12的样品,测量精度为0.41%;针对超铀核素的测量,239/238的丰度灵敏度为(1.5~2.7)×10^(-13),Pu同位素、^(237)Np和^(244)Cm的最低探测限低至10^(-18)g水平。证明该系统已具备对^(14)C、^(129)I和锕系核素的超灵敏测量能力,所获得的测量水平与高能加速器质谱仪(Accelerator Mass Spectrometry,AMS)系统相比具有竞争力。展开更多
文摘Effect of kinetic model parameters on fission product (I-129) activity from fuel to coolant in PWRs has been studied in this work. First a computational model was developed for fission product release into primary coolant using ORIGEN-2 as subroutine. The model is based on set of differential equations of kinetic model which includes fuel-to-gap release model, gap-to-coolant leakage model, and Booths diffusion model. A Matlab based computer program FPAPC (Fission Product Activity in Primary Coolant) was developed. Variations of I-129 activity in Primary Heat Transport System were computed and computed values of i-129 were found in good agreement and deviations were within 2% - 3% of already published data values. Finally, the effects of coolant purification rate, diffusion constant and gas escape rate on I-129 activity were studied and results indicated that the coolant purification rate is the most sensitive parameter for fission product activity in primary circuit. For changes of 5% in steps from −10% to +10% in the coolant purification rate constant (Β), the activity variation after 200 days of reactor operation was 23.1% for the change.
文摘本研究建立了AMS(Accelerator mass spectrum,加速器质谱)测定海水中129 I的气载分离制样方法:对加入载体的海水样品进行氧化还原处理,在加热的条件下将生成的单质碘吹出,并使用吸收装置吸收,后经阴离子交换树脂富集纯化,最后生成用于AMS分析的AgI沉淀,本方法全程回收率50%~70%,在相对密闭的体系中进行,减少了碘的损失,相对于萃取-反萃取的制样方法具有可操作性强,避免有机试剂使用等优点,可用于固态、液态和气态样品中129 I的AMS分析制样。
文摘中国辐射防护研究院(China Institute for Radiation Protection,CIRP)引进一台300 kV多核素低能加速器质谱仪(Multi-Isotope Low-Energy Accelerator mass spectrometry,MILEA),可用于各种基体样品中超低含量的^(14)C、^(129)I和锕系核素(Pu同位素、^(237)Np、Am同位素、Cm同位素及U同位素)的测量。在对该系统进行现场验收及调试测量中,通过对稳定核素从低能端到高能端的传输效率及高能端的电流强度、空白样品中稀有放射性核素与其稳定核素的比值及丰度灵敏度、标准样品中单个样品及多个样品测量的弥散度等关键参数的测试,结果显示:^(14)C/^(12)C最小比值为(1.3±0.1)×10^(-15),测量精度为0.2%;WWI^(129)I/127I最小比值为(3.76±0.2)×10^(-14),测量^(129)I/127I比值为10-12的样品,测量精度为0.41%;针对超铀核素的测量,239/238的丰度灵敏度为(1.5~2.7)×10^(-13),Pu同位素、^(237)Np和^(244)Cm的最低探测限低至10^(-18)g水平。证明该系统已具备对^(14)C、^(129)I和锕系核素的超灵敏测量能力,所获得的测量水平与高能加速器质谱仪(Accelerator Mass Spectrometry,AMS)系统相比具有竞争力。
