辐照加工宝石的放射性测量研究

利用辐照进行天然宝石改色,能显著提升宝石的观赏价值和商业价值。但经反应堆辐照后的宝石含有人工放射性核素,会对相关人员产生照射。本文利用γ能谱分析方法对辐照宝石进行了直接放射性测量。采用实验和蒙特卡罗模拟相结合的方法分析了辐照宝石的几何结构、密度对其γ能谱测量准确性的影响,得到探测效率与能量、样品质量的修正公式,从而实现了无需磨制过程的辐照宝石放射性的γ能谱准确测量。     

Determination of Heat Capacity of Simulated Radioactive Waste Glasses by Drop Calorimetry

The enthalpies of two kinds of simulated radioactive waste glasses have been measured with an ice isothermal calorimeter at temperatures of 424~875 K by means of drop calorimetry. The fitting functions for the enthalpies per gram have been determined by the least squares fitting. Specific heat and average molar heat capacity have been obtained. It is likely that heat capacity of waste glass remarkably depends on its composition especially above its glass transition temperature.     

双探测位置分段γ扫描系统研究

本文以双探测位置的分段γ扫描技术为基础,建立了环放射源探测效率的理论计算方法,其能根据放射源所处的实际位置实时计算出探测效率。在此基础上研发了一套探测系统,实现了对废物桶的自动化探测。使用该系统对单个及多个60 Co和137 Cs及聚氨酯和木头组成的模拟桶进行测量。测量单个及多个放射源活度相对误差平均值分别为10%和7.9%,优于使用传统分段γ扫描技术的探测结果,最后根据测量环境估算了探测系统的最小探测限。     

核技术利用项目环保验收中的放射性流出物监测问题探讨

建设项目竣工后应该进行环境保护验收监测,对于向环境排放放射性物质的建设项目,在验收监测过程中需要进行放射性流出物监测。本文总结了北京市核技术利用项目在环保验收中放射性流出物（废水、废气）监测所遇到的困难和解决措施,为今后解决这些问题提出了针对性建议。     

富氢水对60Co照射比格犬急性血液系统损伤的保护作用研究

本文研究了富氢水对⁶⁰Co γ 射线照射后Beagle犬急性血液系统损伤的保护作用。雄性Beagle犬随机分为对照组、单纯照射组和富氢水干预组。动物经单次2.0 Gy γ射线全身照射后,分别于第2天、第7天,采集动物外周血,检测血液学指标、抗氧化指标、淋巴细胞凋亡率及8-羟基脱氧鸟苷酸(8-OHdG)等。结果表明,在照后第7天,富氢水组红细胞计数(RBC)、血红蛋白含量(HGB)、红细胞压积(HCT)均高于单纯照射组(p＜0.01、p＜0.05、p＜0.05);在照后第2天、第7天,富氢水组血清中总抗氧化能力(T-AOC)均高于单纯照射组(p＜0.01,p＜0.05),丙二醛(MDA)均低于单纯照射组(p＜0.01,p＜0.05);在照后第2天、第7天,富氢水组淋巴细胞凋亡率均低于单纯照射组(p＜0.05,p＜0.01);在照后第7天,富氢水组8-OHdG浓度低于单纯照射组(p＜0.05)。以上结果说明,富氢水可通过抗氧化应激、抗凋亡机制改善照后Beagle犬血液系统损伤。     

2013—2018年山西省放射性废物库库区环境γ辐射水平监测

为了进一步加强对放射性废物库的安全管理,确保辐射环境安全,对2013—2018年山西省放射性废物库库区环境γ辐射剂量率的监测结果进行了分析。结果表明,库区环境γ辐射水平满足《核技术利用放射性废物库选址、设计与建造技术要求(试行)》中有关库房内源坑盖板上方0.5 m处γ辐射剂量率不超过20μGy/h、源库墙外表面0.2 m处γ辐射剂量率不超过2.5μGy/h的规定要求,各年度间环境电离辐射水平处于本底涨落范围内,未对周围环境产生辐射影响,辐射环境质量总体良好。此外,健全的库区安全防范也为促进我省核技术利用和安全、健康、可持续发展提供了坚强保障。     

高放废物玻璃固化体的辐照效应研究进展

本文概述了国内外针对玻璃辐照效应所开展的研究及其进展。介绍了α、β、γ射线在玻璃中产生的微观缺陷类型、相对应的表征手段、不同微观损伤与吸收剂量的关系及其在不同温度条件下的稳定性。介绍了玻璃宏观性质随辐照剂量的改变以及饱和现象,提出了宏观性质的改变和无序度的联系来解释实验结果。最后,介绍了玻璃固化体研究所面临的问题和挑战。     

解读IAEA新放射性废物分类草案

本文介绍了国际原子能机构（IAEA）发布的新放射性废物分类草案的背景和内容,综述了新废物分类图的特点以及笔者对分类草案的几点考虑。     

GRM在轨标定探测器的设计和实现

伽马射线监视器（GRM）上搭载的在轨标定探测器（GCD）用于在轨探头的增益控制,对于探测器在轨探测性能的研究具有重要意义。本文对其各部分电子学的原理设计、偏压补偿电路的高低温实验验证及结果分析、投产加工及镶嵌源灌封设计等研制过程进行了描述,对设计中出现的问题加以验证及改进。实验和测试结果表明,探测器的功能正确,且探测效率、峰位漂移变化等性能指标均满足任务要求,从而表明该设计可保证GCD在轨功能的可靠实现。     

分层γ扫描定量分析中层内放射性非均匀分布影响分析

分层γ扫描(SGS)测量分析方法是核废料与放射性废物定量测量的重要手段,被测样品层内放射性均匀分布是SGS分析方法的基本假设之一。本文采用蒙特卡罗方法模拟计算与实验验证相结合,研究了样品层内放射性非均匀分布对SGS测量分析误差的影响趋势和影响程度。研究表明,当实际样品的层内放射性分布偏离均匀假设时,会导致SGS分析结果偏离实际含量。这一结论与实际测量结果一致。     

对法国高放废物处置安全审评的分析研究

介绍了法国高放废物处置研究现状和规划,对法国高放处置场的审评技术单位法国核与辐射安全研究院（IRSN）所开展的高放处置安全研究和审评工作及其提出的审评原则和审评要点进行了分析研究,并对我国的高放处置安全审评工作提出了建议。     

Proposal for selective isotope transmutation of long-lived fission products using quasi-monochromatic γ-ray beams

We have proposed a new selective isotope transmutation method using photonuclear reactions with quasi-monochromatic γ-ray beams. This method is based on the fact that the particle threshold of a long-lived fission product (LLFP) such as ⁹³Zr, ¹⁰⁷Pd, or ⁷⁹Se is lower than those of stable isotopes of the same chemical element. Therefore, this method has the excellent advantage that LLFPs cannot, in principle, be produced newly even if the target materials include stable isotopes in addition to LLFPs. Furthermore, this method is effective for ¹²⁶Sn, ^{135, 137}Cs, ⁹⁰Sr, and ³H. The nuclear data involved and suitable γ-ray sources are discussed. Laser Compton scattering γ-ray sources and neutron capture γ-rays in nuclear reactors are candidates for this method.     

分层γ扫描层间串扰影响研究

分层γ扫描(SGS)测量分析方法是核废料与放射性废物定量测量分析的重要手段。其中,由于分层形成的临近层对当前层测量的干扰（层间串扰）是分析结果误差的来源之一。本工作研究了串扰及测量和计算误差对串扰方程组解的影响,并通过实验测量和Monte-Carlo模拟计算予以印证。结果表明：在测量和计算误差存在的条件下,适当的串扰对样品中物料总含量分析结果的影响较小。如果希望得到每一分层中物料含量的准确数据,则需对串扰及测量和计算误差有更严格的要求。     

Enrichment of the Uranium Isotopes by Electromigration in a Cation Exchange Membrane

The γ-radiolysis of water subjected to gas bubbling has been studied using a specially desinged gasloop. During the irradiation, N₂ gas was bubbled from the bottom of the irradiation vessel. As the N₂ gas feed rate was raised, the apparent G(H₂) value increased in keeping therewith, from 5 × l0^?3 to 0.26. However in the presence of a sufficient amount of O₂ or H₂O₂, G(H₂) was raised almost to the level of the molecular yield. With reasonable assumptions, it could be concluded that 3～5 × 10^?6 mol/l of H₂O₂ was sufficient to reduce the back reaction of molecular products to less than 10% under the present experimental conditions. It was also found that the G(H₂) value increased with CH₃OH concentration roughly in proportion to log(CH₃OH), and reached 3.1 with 0.1 mol/l CH₃OH.     

Effects of Heat-Treatment and Gamma-Ray Irradiation on the Etch-Pit Formation in Allyl Diglycol Carbonate Resin

Allyl diglycol carbonate resin plates possessing alpha tracks were etched after heat-treatment, or after gamma-ray irradiation. The strong heat-treatment and irradiation brought similar effects to two indicators: etch-pit diameter and bulk etching rate. The heat-treatment above 120°C lasting for 1h and irradiation above 4.0x10² Gy increased the indicators and caused the etch-pits to disappear faster. On the other hand, mild heat-treatment brought the opposite effects to under-cured resin. A reduction of the etch-pit diameter was observed in the resin exposed to heat-treatments between 80°C and 120°C lasting for 1h. These phenomena were observed in the study of plates in which alpha tracks were made after the above mentioned heat-treatment or irradiation. These results suggest not only the conditions under which the resin may be used, but also the possibility of enhancement or suppression of etching speed, and of estimation of thermal history or measurement of gamma-ray dosage.