A burnup calculation was performed to analyze the Apr`es ORIENT process, which aims to create highlyvaluable elements from fission products separated from spent nuclear fuels. The basic idea is to use nuclear transmut...A burnup calculation was performed to analyze the Apr`es ORIENT process, which aims to create highlyvaluable elements from fission products separated from spent nuclear fuels. The basic idea is to use nuclear transmutation induced by a neutron capture reaction followed by a β-decay, thus changing the atomic number Z of a target element in fission products by 1 unit. LWR(PWR) and FBR(MONJU) were considered as the transmutation devices. High rates of creation were obtained in some cases of platinum group metals(44Ru by FBR,46 Pd by LWR) and rare earth(64Gd by LWR,66 Dy by FBR). Therefore, systems based on LWR and FBR have their own advantages depending on target elements. Furthermore, it was found that creation rates of even Z(= Z + 1) elements from odd Z ones were higher than the opposite cases. This creation rate of an element was interpreted in terms of "average 1-group neutron capture cross section of the corresponding target element σc Z defined in this work. General trends of the creation rate of an even(odd) Z element from the corresponding odd(even) Z one were found to be proportional to the 0.78th(0.63th) power of σc Z, however with noticeable dispersion. The difference in the powers in the above analysis was explained by the difference in the number of stable isotopes caused by the even-odd effect of Z.展开更多
IT’S more than a month from Christmas, but 26-year-old Chen Yu has been thinking for quite a while about what gifts she should buy for her family, friends and boyfriend. Meanwhile, her father has tried to dissuade he...IT’S more than a month from Christmas, but 26-year-old Chen Yu has been thinking for quite a while about what gifts she should buy for her family, friends and boyfriend. Meanwhile, her father has tried to dissuade her, "There’s no point for a Chinese to observe a foreign holiday." Ironically, her father Chen Rui has been racking his brain for similar solutions- what gifts to buy for his relatives and friends, not for Christmas but for New Year and Spring Festival. The problem is not a lack of options, either for occasions to celebrate or how to do it. Excessive choice is what has complicated everyone’s decision-making.展开更多
文摘A burnup calculation was performed to analyze the Apr`es ORIENT process, which aims to create highlyvaluable elements from fission products separated from spent nuclear fuels. The basic idea is to use nuclear transmutation induced by a neutron capture reaction followed by a β-decay, thus changing the atomic number Z of a target element in fission products by 1 unit. LWR(PWR) and FBR(MONJU) were considered as the transmutation devices. High rates of creation were obtained in some cases of platinum group metals(44Ru by FBR,46 Pd by LWR) and rare earth(64Gd by LWR,66 Dy by FBR). Therefore, systems based on LWR and FBR have their own advantages depending on target elements. Furthermore, it was found that creation rates of even Z(= Z + 1) elements from odd Z ones were higher than the opposite cases. This creation rate of an element was interpreted in terms of "average 1-group neutron capture cross section of the corresponding target element σc Z defined in this work. General trends of the creation rate of an even(odd) Z element from the corresponding odd(even) Z one were found to be proportional to the 0.78th(0.63th) power of σc Z, however with noticeable dispersion. The difference in the powers in the above analysis was explained by the difference in the number of stable isotopes caused by the even-odd effect of Z.
文摘IT’S more than a month from Christmas, but 26-year-old Chen Yu has been thinking for quite a while about what gifts she should buy for her family, friends and boyfriend. Meanwhile, her father has tried to dissuade her, "There’s no point for a Chinese to observe a foreign holiday." Ironically, her father Chen Rui has been racking his brain for similar solutions- what gifts to buy for his relatives and friends, not for Christmas but for New Year and Spring Festival. The problem is not a lack of options, either for occasions to celebrate or how to do it. Excessive choice is what has complicated everyone’s decision-making.
