兰州重离子研究装置（HIRFL）感生放射性剂量率的测量

本文报道兰州重离子研究装置（ＨＩＲＦＬ）实验终端钢筒表面和实验靶处的感生放射性外照射剂量率测量的方法和结果，分析了感生放射性剂量率的衰减规律。根据实测数据评估了操作人员所受的外照射剂量，并提出了为降低操作人员受照剂量而采取的防护措施。     

数字减影血管造影术施术者受照剂量的影响因素

探讨DSA术者受照剂量的影响因素,为优化辐射防护提供思路。介入手术施术者的受照剂量与手术难度、检查或治疗类别、手术熟练程度和工作量等诸多因素有关,透视时间与入射点空气比释动能和剂量面积乘积相关性较差。缩小照射野、降低脉冲频率、手动设定管电压均可有效降低施术者的受照剂量。穿戴个人防护用品虽能有效降低施术者受照剂量,但对眼晶体(特别是左眼)和手部的防护效果欠佳。因此,除进行针对性辐射安全培训外,还应常规监测这些部位的受照剂量。     

适用于放射性样品的小冲杆试验装置

<正>由于小冲杆试验样品较小,很难通过在热室中使用机械手操作完成试验。为了对放射性样品进行小冲杆试验,设计了1套针对放射性试样的小冲杆试验装置,以减少操作人员的受照剂量。试验装置示意图如图1所示。试验前,将顶丝旋紧固定住冲杆,将球漏斗置于下夹模上表面,用球勺(前段有φ1mm×1mm小孔)取出φ1mm陶瓷球并放入球漏斗中,陶瓷球即可落入下夹模     

紫芝多糖对辐射所致小鼠骨髓有核细胞微核效应的防护作用

本文报道了紫芝多糖对不同剂量~(60)Coγ射线诱发小鼠骨髓有核细胞微核细胞率影响的观察结果。结果表明,紫芝多糖对受照小鼠骨髓有核细胞的微核效应具有明显的防护作用。对瑞士白变种小鼠,受照剂量为0—4.728Gy 范围时,剂量减低系数(DRF)为1.72;对 LACA 小鼠,受照剂量在0—3.152Gy 范围时,DRF 为1.73,和L-半胱氨酸的防护效果很接近。     

江苏省常州地区医疗机构放射工作人员个人剂量监测

为了解常州地区非军队医疗机构的放射工作人员的受照剂量情况,对2017—2018年放射工作人员的外照射个人剂量监测结果进行回顾性分析。结果表明:(1)常州地区非军队医疗机构医学放射工作人员的年均受辐射剂量均低于国家标准限值(5 mSv/a);(2)市级管理医疗机构监测率及防护有效性高于区级管理医疗机构;(3)年度剂量平均值比较:核医学>其他X射线影像诊断相关>X射线影像诊断>口腔X射线影像诊断相关>介入放射学>放射治疗。结论认为,常州地区非军队医疗机构医学放射工作人员的防护措施比较完善,但区级管理的基层医疗机构及私立医疗机构仍需加强管理,并应提高放射工作人员的自我保护意识。     

铀作业人员外周血T淋巴细胞微核的初步观察

本文报道了86名铀作业人员和80名菲放射性工作人员外周血T淋巴细胞微核细胞率、微核率,以及职业受照人员的T淋巴细胞微核细胞率与累积剂量,放射工龄关系的研究结果。结果表明。职业受照人员的T淋巴细胞微核细胞率、微核率较对照组有统计学意义的增加;而且似有随着剂量与累积剂量、放射工龄的增加而增高的趋势。但经相关检验,相关性不显著。认为T淋巴细胞微核测定法也是评价职业受照者群体辐射效应的一种简便而有价值的细胞遗传学指标。     

125I种籽源植入手术中工作人员的电离辐射防护

为探讨操作125I种籽源应采取适当防护措施的必要性,阐述了125I种籽源植入手术各阶段的电离辐射监测结果,并对无防护条件下手术医生可能受到的辐射剂量做出估算:对于总活度为925 MBq的40粒种籽源,在开源、核对及装源入植源器操作时,操作距离30 cm,操作时间10 min,则操作者受照剂量为70 μSv;对于手术医生,从辐射防护角度进行估计,一例手术,包括插植和带源缝合操作,医生在其操作位置的受照剂量可达184 μSv.并对125I种籽源植入手术中工作人员的电离辐射防护提出了建议.     

“医疗照射中的放射防护”专题介绍

由于医疗照射是公众所受到的非天然电离辐射中的最主要部分 ,而近几十年来新的放射性诊断和治疗设备不断出现 ,并且很快地被投入临床使用之中 ,因此“医疗照射中的放射防护”专题成为了 IRPA-1 0大会的主要内容。会议中各国学者分别就在放射诊断学 (包括介入放射学 )、核医学和放射治疗临床工作中 ,病人与工作人员受照剂量的测量、降低其照射剂量的方法、对健康状况的评价、质量保证 /控制工作等等问题发表了各自的论文并进行了广泛的讨论。     

运输中的要求（第6章讲解）

1.运输中的隔离6.1条引自205、206(指 IAEA6号丛书)条,规定了放射性货包在运输中与人员及未感光胶片应有的隔离限值,即在运输中利用距离防护方法来减少受照剂量。Ⅰ级货包与人员之间不必考虑隔离。因为Ⅰ     

职业性急性放射性皮肤损伤病例诊断评价

采取问卷调查形式,收集并统计、分析2016—2019年确诊的6例职业性急性放射性皮肤损伤病例。结果表明,工业辐照和工业探伤是导致工人职业性急性放射性皮肤损伤的重点工种,放射单位应加强放射工作人员的培训,尤其是岗前培训,提高防护意识;工人进入放射工作场所,应佩戴常规剂量计,并在关键岗位佩戴报警式剂量计;诊断职业性急性放射性皮肤损伤涉及诊断医师对标准的熟悉程度和严格把握采用,关键在于明确的受照剂量和临床表现。     

医源性电离辐射损伤及其生物医学防护

随着核与辐射技术在医学检查、诊断和治疗领域运用的增加,世界范围受照人群不断增多,医源性辐射已成为人类最主要的人工辐射来源之一。医疗机构和个人在选择利用放射手段获取诊断和治疗利益的同时,需要注意和防护伴随的辐射损伤效应。本文介绍了医源性辐射及其危害、机体组织的辐射损伤特性和类型、辐射生物效应分子及效应调节研究的进展,简要概述目前临床已经使用或最具应用潜力的辐射防护策略。     

Development and diversity and defense-in-depth application of ABWR feedwater pump and controller model

This work developed an advanced boiling water reactor (ABWR) feedwater pump and controller model, which was incorporated into Personal Computer Transient Analyzer (PCTran)-ABWR, a nuclear power plant simulation code. The feedwater pump model includes three turbine-driven feedwater pumps and one motor-driven feedwater pump. The feedwater controller includes a one-element/three-element water level controller and a specific feedwater speed controller for each feedwater pump. The performance tests, including step change of dome pressure, feedwater pumps transfer, inadvertent closure of all turbine control valves, and one feedwater pump trip at 100% power, demonstrate the feasibility of dynamic response of stand-alone model and incorporated model. Furthermore, a diversity and defense-in-depth analysis is performed to demonstrate the feasibility for motor-driven feedwater pump as an emergency core cooling system (ECCS) automatic diverse back-up. In Lungmen nuclear power plant (NPP), a diverse manual initiation means for the high pressure core flooder (HPCF) loop C is designed as the back-up of digitalized engineered safety features actuation system (ESFAS). If the motor-driven feedwater pump (MDFWP) can be an automatic digital diverse back-up for ESFAS, Lungmen NPP would be more robust to defend against software common-cause failure (CCF).     

核与辐射风险的认知与沟通

面对公众对核与辐射风险极度敏感的现象,本文阐述了对风险的认知及影响认知程度的因素,介绍了风险沟通的发展阶段和四种类型,并给出了若干有效的风险沟通策略建议。     

Sorption methods of separating barium and radium,aluminum and gallum,and zirconium and hafnium

Chromatographic methods of separating elements with very similar properties have now been developed. However, a number of these methods are difficult to use industrially as their throughput is low. The efficiency of chromatographic separation methods could be increased considerably by using appropriate complex formers, which decrease the effective concentration of the ions being separated, and,in the first approximation, this is equivalent to a decrease in the amount of elements being separated. The difference in the formation constants of the complex compounds increases the separation coefficient. By investigating chromatographic separation with the use of various complex formers, we found the optimal conditions for separating barium and radium, zirconium and hafnium, and aluminum and gallium. The throughput of these methods, with respect to the macroelement was 15–60 kg/hr per m² of column cross section.     

Thermophysical and mechanical properties of CrB and FeB

ABSTRACT

Fuel debris in the Fukushima Daiichi nuclear power plant is thought to contain borides that are generated from B₄C control material. In order to successfully devise methods to effectively remove the debris material, characterization of the properties of the fuel debris is essential. This paper presents some of the thermophysical and mechanical properties of two types of borides, FeB and CrB, and compares them with those of Fe₂B and ZrB₂. These are the representative borides that might have been generated in the Fukushima Daiichi (1F) nuclear power plant accident. We observed that the thermal conductivity values of both CrB and FeB are much lower than that of ZrB₂, and are similar to that of Fe₂B. Moreover, the Vickers hardness and fracture toughness of FeB and CrB are almost identical to each other, and similar to those of ZrB₂ and Fe₂B.     

Distribution and Fixation of Cesium and Strontium in Zeolite A and Chabazite

The selective removal and fixation of Cs and Sr have been studied in zeolite A and chabazite. Cesium ion was preferentially distributed into chabazite with a high distribution coefficient (K _Cs>10³ cm³·g^?1) in the presence of NaCl (10^?1 mol·dm^?3). The K _Sr values for zeolite A attained about 10³ cm³·g^?1 in the pH range of 8～10, and they gradually decreased with an decrease in pH.

The initial rate of Cs adsorption was fairly fast in chabazite, and the adsorption ratio reached almost 100% within a few hours. The adsorption ratio of Sr in binderless A zeolite reached almost 100% after 15 h. The adsorption of Cs and Sr on these zeolites was followed by Langmuir-type isotherm. Cesium forms of these zeolites recrystallized to pollucite (CsAlSi₂O₆) above 900°C for zeolite A and above 1,200°C for chabazite. As for Sr forms, these zeolites changed to SrAl₂Si₂O₆ above 900°C.

These recrystallized phases were suitable hosts for the immobilization of Cs and Sr in the nuclear waste solutions.     

全国核与辐射安全监管信息系统的研究和建议

文章简要介绍了全国核与辐射安全监管信息系统的前期规划建设情况,包括基本建设内容、系统总体架构、以及工作中发现的影响和制约工作开展的主要问题,并提出了建议。     

测温热电偶拔出回收技术及回收处理装置

核电站反应堆测温热电偶回收装置是堆芯热电偶检修、更换、回收的专用设备。本文结合３００ＭＷ反应堆型，介绍了一种结构简单、操作方便、使用安全可靠的热电偶拔出回收技术及回收处理装置。     

核电与常规电的异同——浅议从常规电向核电工作转变的体会和认识

随着国家"积极推动核电发展"指导思想的贯彻落实,尤其是2006年国家确定引入美国西屋AP1000核电技术路线之后,以常规电为背景的一些电力集团均不同程度地参与了核电前期开发、工程建设等方面的工作,传统的核电企业如中核集团、中广核集团也大量地招聘、招收了一定比例的常规电从业人员。这些长期从事常规电工作的人员从事核电工作以后,如何能够尽快实现工作转变,早日适应核电的工作要求,做到从工作的转变到观念的转变,知识的转变,思维方式的转变,熟练驾驭的转变,从而成为一名合格的核电工作者。本文从核电的技术特点、管理特点、文化特点和从事核电工作应关注的几个方面问题进行阐述,以期为这一特定时期的核电发展贡献一份力量。     

Mechanical and thermal properties of Zr-B and Fe-B alloys

ABSTRACT

After the core meltdown in the Fukushima Daiichi (1F) nuclear power plant, various compounds in metal boride systems could potentially form as a result of the reactions between B₄C (control material) and Fe, Zr alloys (control-blade sheaths, zircaloy claddings, channel box, etc.). Some previous studies have focused on the properties of intermetallic compounds of the Zr-B and Fe-B systems, such as ZrB₂, FeB, and Fe₂B. However, during the solidification of fuel debris, composites of these intermetallics rather than large chunks of single-phase intermetallics will form. This situation makes the understanding of the composition dependence of the mechanical and thermal properties of these metal borides a major task before debris retrieval takes place. In this study, we first investigated the temperature-dependent thermal conductivity of Fe-B and Zr-B eutectics from room temperature up to 900^°C. We were then able to evaluate the composition-dependent indentation hardness of these metal borides at room temperature. Based on our experimental data, we concluded that the hardness and thermal conductivity of the Fe-B, Zr-B composites can be well estimated using the properties of the composites’ corresponding components, with Rule of Mixtures and Effective Medium Theory (EMT) calculations, respectively.