Systems Analysis of Spent Fuel Management in Japan, (I)

Spent fuel accumulation in the future and its appropriate management strategy for Japan is analyzed by “SFTRACE” (Spent Fuel Storage, TRAnsportation and Cost Evaluation System) is introduced, which consists of 3 sub-models; (1) the economic cost data base for spent fuel storage technologies, (2) the long-range simulation of reactor mix and plutonium (Pu) utilization, and (3) the detailed simulation of spent fuel management strategies.

The long-range simulation sub-model presents a macroscopic overview on how much amount of spent fuel stockpile should be addressed nationwide at a certain time point. A preliminary calculation shows that the spent fuel storage needs in Japan to the year 2050 will vary significantly, from a decrease towards zero or a continuous increase up to 20,000–25,000 tHM. The sub-model for spent fuel management simulation is the tool to demonstrate nationwide strategies to deal with spent fuel accumulation, either at each power station site or a number of centralized facilities in the given time horizon, with associated needs of transportation. An illustrative analysis shows trade-off relationship among factors involved in spent fuel management strategies, such as between “away from reactor (AFR)” storage capacity and overall transportation requirements, which vividly demonstrates the usefulness of the integrated analytic tool.     

Oxidation and Gas Release Behavior of UC,U(C,N) and UN at High Temperature

A study was made of the oxidizing behavior at high temperature (800°–1,800°C) in vacuum of UC, UN and U(C,N) samples containing added oxygen in excess amounts, through observations of gas release, X-ray diffraction analysis, and microphotography.

The oxidation in vacuum of UC and U(C,N) was found to proceed above 1,200°C by stepwise reactions from one temperature interval to the next, the process differing however according to the chemical state of the oxygen present in the samples. In the temperature range below 1,200° C, the UC and U(C,N) samples reacted violently with the free oxygen present in dissolved state, to form UO₂. Between 1,200° and 1,400° C the UO₂ thus produced reacted with the UC or U(C,N), forming solid solutions of U(C,O) and U(C,N,O) respectively: Above 1,600°C, these solid solutions gradually decomposed back into UC and U(C,N), and U. In all stages of oxidation, large amounts of CO—and N₂ in the case of U(C,N)—evolved from the samples as reaction products. In the case of UN, no reaction was observed below 1,200°C, and only oxidized above that temperature to form UO₂ and N₂ by the action of the dissolved oxygen present.

These results indicate that in the case of UC and U(C,N), the quantity of gases evolving from the oxidation is dictated by the total amount of oxygen contained in the samples, while that from UN is dependent on the amount of molecular oxygen alone.     

LaNi5Dx(x=0, 0.3)型贮氢材料的微观结构研究

简要介绍了LaNi5型贮氢材料的贮氢原理,处理了LaNi5Dx(x＝0, 0.3)的中子衍射数据,得到了该材料的部分微观结构信息,通过Material studio(MS)程序建立了其理论模型,并用MS中的Castep模块对该材料进行了第一性原理计算,得到了结构优化后的晶格常数、能量等参数信息,通过对这些参数的比较,找到了LaNi5D0.3中D原子的占位位置,结果与实验精修的结果是一致的.     

^176Hf（n,2n）^175Hf和^185Re（n,2n）^184Re^m,g反应截面研究

用中国原子能科学研究院ＨＩ－１３串列加速器,高压倍加器和北京大学４．５ＭＶ静电加速器分别获得能量为１０－１２,１４和１８ＭｅＶ的中子,了＾１７６Ｈｆ（ｎ,２ｎ）和＾１８５Ｒｅ（ｎ,２ｎ）的反应堆面,并与现有的实验数据作了比较,初步搞清了分歧的主要原因和激发函数的走向。     

山西省城市放射性废物库周围辐射环境监测(2016—2019)

山西省核技术利用项目产生的放射性固体废物(源)暂存于山西省城市放射性废物库。2016—2019年,废物库废旧放射源存量增加近千枚。2016—2019年,对废物库库区周围辐射环境(包括:库区周围γ辐射剂量率,库区α、β表面污染水平,气溶胶总β水平,库区及周围水中总α、总β水平,库区及周围居民点土壤中γ核素水平等项目)的监测结果显示,废物库周边辐射水平处于天然辐射水平范围内,未见可察觉的改变。     

Model-based cross section calculations on production of ~(43,34)Sc,~(45)Ti,~(51)Cr,~(54)Mn,and ~(55)Fe radioisotopes

A cross section database on excitation functions of reactions produced by charged particles is essential for many areas of nuclear research. Particularly, accurate knowledge on nuclear cross sections for the cyclotron production of radioisotopes is very important for nuclear medicine. In the present paper, the cross section calculations for the production of~(43),~(34)Sc,~(45)Ti,~(51)Cr,~(54)Mn, and~(55) Fe radioisotopes were carried out by the use of ALICE/ASH code using the Fermi gas model, Kataria Ramamurthy Fermi gas model, and superfluid nuclear model for nuclear level density. Thereby, these model calculations were compared with the available measured data.     

我国膳食中~(90)Sr、~(137)Cs、~(226)Ra、~(228)Ra、~(210)Pb 和~(210)Po含量及其所致内照射剂量

作为1990年全国总膳食调查的放射性物质部分,本文报道了组成我国膳食的各类食品中~(90)Sr、~(137)Cs、~(226)Ra、~(228)Ra、~(210)Pb 和~(210)Po 含量的测定结果;按调查所得膳食组成和食品中核素含量,估算了我国居民(成年男子)当前这些核素经食入所致年摄入量和待积有效剂量当量。结果表明,每年食入所致总待积有效剂量当量约为0.24 mSv,贡献较大的食品是蔬菜、水产品和谷类,贡献较大的核素为~(210)Pb、~(210)Po 和~(228)Ra。这些结果更新了我国膳食中这些核素的资料,补充了来自饮水的数据。文中还讨论了我国膳食组成的地区差异及其对居民摄入量和所致内照射剂量的影响。     

~(107)Ag(d,2n)~(107)Cd和~(109)Ag(d,2n)~(109)Cd反应的激发函数

用13.4MeV的氘束轰击天然银迭靶,银箔前后用铝箔作捕集减能膜。实验确定了~(107)Ag(d,2n)~(107)Cd和~(109)Ag(d,2n)~(109)Cd反应的激发函数,同时作了理论计算。由结果可见,实验值与理论值吻合得很好。     

Isospin Distribution of Fragments in Reaction ~(96)Ru ~(96)Ru, ~(96)Ru ~(96)Zr,~(96)Zr ~(96)Ru,and ~(96)Zr ~(96)Zr at Beam Energy 400 AMeV

The isospin distribution of particles and fragments in collisions 96Ru 96Ru, 96Ru 96Zr, 96Zr 96Ru, and 96Zr 96Zr at beam energy 400 AMeV is studied with isospin dependent QMD model. We find the rapidity distribution of difference between neutron-proton number in neutron rich nucleus-nucleus collisions at intermediate energies is sensitive to the isospin dependent part of nuclear potential. The study of the N/Z ratio of nucleons, light charged particles (LCP) and intermediate mass fragments (IMF) shows that the isospin dependent part of nuclear potential drives IMF to be more isospin symmetric and emitted nucleons to be more neutron rich. We also study the time evolution of the isospin distribution     

用于束流输运线设计的专家系统OPTRAN（Ver1.0）及其应用

介绍了一套用于束流输运线设计的专家系统ＯＰＴＲＡＮ（Ｖｅｒ１．０）。详细阐述了组成其智能化部分的知识库和推理机，利用ＯＰＴＲＡＮ完成了Ｃｙｃｌｏｎｅ３０回旋加速器束流引出输运线的设计。     

^179Hf（n,2n）^178Hf^m2和^209Bi（n,2n）^208Bi反应截面的测量

用活化法测量相对于~(93)Nb(n,2n)~(92)Nb~m反应的~(179)Hf(n,2n)~(178)Hf~(m2)的反应截面和相对于~(27)Al(n,2n)~(24)Na反应的~(209)Bi(n,2n)~(208)Bi的反应截面。在中子能量为14.4 MeV处~(179)Hf(n,2n)~(178)Hf~(m2)反应的测量截面为(6.04±0.32)×10~(-31)m~2。在中子能量为14.6 MeV处~(209)Bi(n,2n)~(208)Bi反应的测量截面为(2279±173)×10~(31)m~2。在这些测量中,中子能量是用~(90)Zr(n,2n)~(89)Zr~(m+8)反应和~(93)Nb(n,2n)~(92)Nb~m反应的截面比法测定的。     

石油亚砜萃取U(Ⅵ)、Th(Ⅳ)的研究

报道了石油亚砜(PSO)-煤油从硝酸介质中萃取铀(Ⅵ)、钍(Ⅳ)的实验结果。系统研究了硝酸浓度、PSO浓度、盐析剂浓度、铀(Ⅵ)浓度以及温度等对铀(Ⅵ)、钍(Ⅳ)萃取分配比的影响,发现PSO萃取规律与磷酸三丁酯(TBP)和二正辛基亚砜(DOSO)相类似。实验表明:当硝酸浓度在5—6mol/1间,D_v有一极大值,而D_(Th)极大值则出现在3—4mol/1之间。用斜率法测得铀(Ⅵ)、钍(Ⅳ)的溶剂化数为2和3。还计算了它们的萃取平衡常数和焓变。     

Measurement of (d,p) and (d,α) differential cross-sections for N

The differential cross-sections for ¹⁴N(d,p₀)¹⁵N, ¹⁴N(d,p₁₊₂)¹⁵N, ¹⁴N(d,α₀)¹²C and ¹⁴N(d,α₁)¹²C have been measured in the energy range from 0.7 to 2.2 MeV at the laboratory angle of 150°. The obtained results are compared with data published in the literature. Discrepancies between new and previously acquired data are discussed. The cross-sections measured in the present work were uploaded to the IBANDL data base <http://www-nds.iaea.org/ibandl/>.     

~(238)U,~(235)U和~(93)Nb的次级中子能谱和双微分截面计算

一、引言自1966年Griffin提出激子模型以来,经过人们多年的工作,激子模型在计算次级中子能谱方面取得了一定的成功,用于角分布计算也有所进展。但迄今预平衡计算和平衡(蒸发)计算不能统一,计算结果不能定量地符合实验。其一个主要的原因是激子态     

(n,2n)和(n,3n)激发函数的计算

本文从入射中子能量为E=14MeV的σ_(n,2n)实验值出发,应用复合核模型,计算了十三种无分支比复合核衰变的非裂变重核(A>169)的(n,2n)、(n,3n)激发函数。与实验激发曲线比较,讨论了计算的合理性和可靠性。     

~(89)Y(n,2n)~(88)Y反应截面测量

利用活化法的基本原理和相对测量方法,测量得到13.5～14.8MeV的D-T中子作用下的89Y(n,2n)88Y反应截面。89Y(n,2n)88Y反应截面为629～1053mb,相对不确定度为1.7%。并与采用大液闪测量的实验结果和ENDF/B-6库的截面数据进行了比较,当中子能量为14.1MeV处ENDF/B-6数据与实验值的比值为0.99。     

Yield ratio of neutrons to protons in ~(12)C(d,n)~(13)N and ~(12)C(d,p)~(13)C from 0.6 to 3 MeV

The neutron yield in the~(12)C(d,n)~(13)N reaction and the proton yield in the~(12)C(d,p)~(13)C reaction have been measured using deuteron beams of energies 0.6-3 MeV.The deuteron beam is delivered from a 4-MeV electrostatic accelerator and bombarded on a thick carbon target.The neutrons are detected at 0°,24°,and 48°and the protons at135°in the laboratory frame.Further,the ratio of the neutron yield to the proton yield was calculated.This can be used to effectively recognize the resonances.The resonances are found at 1.4 MeV,1.7 MeV,and 2.5 MeV in the~(12)C(d,p)~(13)C reaction,and at 1.6 MeV and 2.7 MeV in the~(12)C(d,n)~(13)N reaction.The proposed method provides a way to reduce systematic uncertainty and helps confirm more resonances in compound nuclei.