为了促进激光诱导击穿光谱技术在核工业领域中的应用与发展,利用飞秒激光对高纯石墨中的钍(Th)元素开展了定量分析研究。采用标准加样法制备了钍含量在0.35%~35.15%范围内的9个分析样品,以类比钍基核燃料中的钍含量。通过改变光谱采集...为了促进激光诱导击穿光谱技术在核工业领域中的应用与发展,利用飞秒激光对高纯石墨中的钍(Th)元素开展了定量分析研究。采用标准加样法制备了钍含量在0.35%~35.15%范围内的9个分析样品,以类比钍基核燃料中的钍含量。通过改变光谱采集方式、延时条件及调节飞秒激光脉冲能量对实验条件进行优化。在优化的实验条件下,对所有样品进行激发以采集等离子体光谱信息用于定量分析研究。得出以下结果:对比定点激发采集光谱结果,采用靶面连续移动式的光谱重复性好,钍原子(Th I 396.21 nm)谱线强度获得大约2倍的增强,重复测量的相对标准偏差由20.4%降至5.7%;高含量区间内钍元素谱线存在明显的自吸收效应,采用指数函数对整个含量区间与分析线(Th I 394.42 nm、396.21 nm和766.53 nm)强度进行非线性拟合,可以有效获取分析线的饱和阈值;基本定标法适用于饱和阈值以下的含量区间,分析线对较低含量的未知样品的预测分析具有较高的精确度;采用内标法(以C I 247.85 nm线为内标线),可以实现积分强度和峰值强度与整个区间含量的线性拟合,其中,基于高饱和阈值分析线(766.53 nm)的积分强度能够较好地实现高含量未知样品的含量预测。实验结果说明:飞秒激光诱导击穿光谱技术具有钍基核燃料循环过程中钍含量监测分析的潜力。展开更多
Study on the behavior of thorium based fuel in a fuel bundle is the aim of this Simulation.check the spectrum flux in theoretical sample Shown that(Th,U)and(Th,Pu)cycle can work in one fuel bundle.
The possibility of utilizing thorium as a fuel in a pressurized water reactor(PWR)has been proven from the neutronic perspective in our previously published work without assessing the thermal hydraulic(TH)and solid st...The possibility of utilizing thorium as a fuel in a pressurized water reactor(PWR)has been proven from the neutronic perspective in our previously published work without assessing the thermal hydraulic(TH)and solid structure performances.Therefore,the TH and solid structure performances must be studied to confirm these results and ensure the possibility of using a thorium-based fuel as an excellent accident-tolerant fuel.The TH and solid structure performances of thorium-based fuels were investigated and compared with those of UO_(2).The radial and axial power peaking factors(PPFs)for UO_(2),(^(232)Th,^(235)U)O_(2),and(^(232)Th,^(233)U)O_(2)were examined with a PWR assembly to determine the total PPF of each one.Both Gd_(2)O_(3)and Er_(2)O_(3)were tested as burnable absorbers(BAs)to manage the excess reactivity at the beginning of the fuel cycle(BOC)and reduce the total PPF.Er_(2)O_(3)resulted in a more significant reduction to the total PPF and,therefore,a greater reduction to the temperature distribution compared to Gd_(2)O_(3).Given these results,we analyzed the effects of adding Er_(2)O_(3)to thorium-based fuels on their TH and solid structure performances.展开更多
The purpose of the paper is to study the performance of the CANDU(Canada Deuterium Uranium)reactor when the reactor core is loaded with thorium fuel mixed with plutonium isotopes with ratio 3 and 5%.A three dimensiona...The purpose of the paper is to study the performance of the CANDU(Canada Deuterium Uranium)reactor when the reactor core is loaded with thorium fuel mixed with plutonium isotopes with ratio 3 and 5%.A three dimensional model is designed for the core of CANDU reactor.The computer code MCNPX(Monte Carlo N–Particle Transport)is used to calculate the processes in its core.The results are compared with natural UO2 case which is the typical fuel of the reactor.The results show that the multiplication factor of the reactor is higher even in the case of thorium fuel mixed with 3%plutonium isotopes,which indicates longer neutron life cycle length and more economic utilization of the reactor.展开更多
钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐...钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐堆相关重大技术挑战,研制出工业示范级钍基熔盐堆,实现钍资源的有效使用和核能的综合利用。钍基核燃料具有232Th/233U转换效率高、在热中子堆中也能增殖、产生较少的高毒性放射性核素、有利于防核扩散等优点,但也面临燃料制备困难、232U衰变子核的强γ辐射给乏燃料处理和燃料再加工带来的困难、钍铀转换反应链中间核233Pa会吸收堆内中子从而影响233U产量。核燃料利用的工作模式有开环模式、改进的开环模式和闭环模式。熔盐堆是第四代反应堆的6个候选堆型之一,非常适合用作钍铀燃料循环,熔盐堆加上干法在线分离技术有可能实现完全的钍铀燃料闭式循环。本世纪初提出的氟盐冷却高温堆(Fluoride salt-cooled High temperature Reactors,FHRs),用氟化熔盐作为冷却剂,采用TRISO燃料颗粒作为核燃料,其中球床型氟盐冷却高温堆可以在改进的开环模式实现钍铀燃料循环。熔盐堆良好的高温特性使其成为核能非电应用主要候选者之一,反应堆产生的高温热可直接用于页岩油开采和高温制氢等工业领域。展开更多
文摘为了促进激光诱导击穿光谱技术在核工业领域中的应用与发展,利用飞秒激光对高纯石墨中的钍(Th)元素开展了定量分析研究。采用标准加样法制备了钍含量在0.35%~35.15%范围内的9个分析样品,以类比钍基核燃料中的钍含量。通过改变光谱采集方式、延时条件及调节飞秒激光脉冲能量对实验条件进行优化。在优化的实验条件下,对所有样品进行激发以采集等离子体光谱信息用于定量分析研究。得出以下结果:对比定点激发采集光谱结果,采用靶面连续移动式的光谱重复性好,钍原子(Th I 396.21 nm)谱线强度获得大约2倍的增强,重复测量的相对标准偏差由20.4%降至5.7%;高含量区间内钍元素谱线存在明显的自吸收效应,采用指数函数对整个含量区间与分析线(Th I 394.42 nm、396.21 nm和766.53 nm)强度进行非线性拟合,可以有效获取分析线的饱和阈值;基本定标法适用于饱和阈值以下的含量区间,分析线对较低含量的未知样品的预测分析具有较高的精确度;采用内标法(以C I 247.85 nm线为内标线),可以实现积分强度和峰值强度与整个区间含量的线性拟合,其中,基于高饱和阈值分析线(766.53 nm)的积分强度能够较好地实现高含量未知样品的含量预测。实验结果说明:飞秒激光诱导击穿光谱技术具有钍基核燃料循环过程中钍含量监测分析的潜力。
文摘Study on the behavior of thorium based fuel in a fuel bundle is the aim of this Simulation.check the spectrum flux in theoretical sample Shown that(Th,U)and(Th,Pu)cycle can work in one fuel bundle.
文摘The possibility of utilizing thorium as a fuel in a pressurized water reactor(PWR)has been proven from the neutronic perspective in our previously published work without assessing the thermal hydraulic(TH)and solid structure performances.Therefore,the TH and solid structure performances must be studied to confirm these results and ensure the possibility of using a thorium-based fuel as an excellent accident-tolerant fuel.The TH and solid structure performances of thorium-based fuels were investigated and compared with those of UO_(2).The radial and axial power peaking factors(PPFs)for UO_(2),(^(232)Th,^(235)U)O_(2),and(^(232)Th,^(233)U)O_(2)were examined with a PWR assembly to determine the total PPF of each one.Both Gd_(2)O_(3)and Er_(2)O_(3)were tested as burnable absorbers(BAs)to manage the excess reactivity at the beginning of the fuel cycle(BOC)and reduce the total PPF.Er_(2)O_(3)resulted in a more significant reduction to the total PPF and,therefore,a greater reduction to the temperature distribution compared to Gd_(2)O_(3).Given these results,we analyzed the effects of adding Er_(2)O_(3)to thorium-based fuels on their TH and solid structure performances.
文摘The purpose of the paper is to study the performance of the CANDU(Canada Deuterium Uranium)reactor when the reactor core is loaded with thorium fuel mixed with plutonium isotopes with ratio 3 and 5%.A three dimensional model is designed for the core of CANDU reactor.The computer code MCNPX(Monte Carlo N–Particle Transport)is used to calculate the processes in its core.The results are compared with natural UO2 case which is the typical fuel of the reactor.The results show that the multiplication factor of the reactor is higher even in the case of thorium fuel mixed with 3%plutonium isotopes,which indicates longer neutron life cycle length and more economic utilization of the reactor.
文摘钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐堆相关重大技术挑战,研制出工业示范级钍基熔盐堆,实现钍资源的有效使用和核能的综合利用。钍基核燃料具有232Th/233U转换效率高、在热中子堆中也能增殖、产生较少的高毒性放射性核素、有利于防核扩散等优点,但也面临燃料制备困难、232U衰变子核的强γ辐射给乏燃料处理和燃料再加工带来的困难、钍铀转换反应链中间核233Pa会吸收堆内中子从而影响233U产量。核燃料利用的工作模式有开环模式、改进的开环模式和闭环模式。熔盐堆是第四代反应堆的6个候选堆型之一,非常适合用作钍铀燃料循环,熔盐堆加上干法在线分离技术有可能实现完全的钍铀燃料闭式循环。本世纪初提出的氟盐冷却高温堆(Fluoride salt-cooled High temperature Reactors,FHRs),用氟化熔盐作为冷却剂,采用TRISO燃料颗粒作为核燃料,其中球床型氟盐冷却高温堆可以在改进的开环模式实现钍铀燃料循环。熔盐堆良好的高温特性使其成为核能非电应用主要候选者之一,反应堆产生的高温热可直接用于页岩油开采和高温制氢等工业领域。
