The collective dose equivalent in evaluated region of bone-coal power stations and bone-coal shafts

1 Introduction The reserve of bone-coal in Hubei, Hunan, Ji-angxi, Zhejiang and Anhui Provinces accounts for about 90% of total reserve in China. More than two hundred years ago, local people spontaneously started to mine the bone-coal on a small scale. At present, the bone-coal is not only used to make lime and then the lime used as a building material or to improve the soil, but also used as a kind of fuel for generating electric-ity. However, the chimney’ exhaust of the bone-coal power …     

Protection of the public in situations of prolonged radiation exposure. The application of the Commission's system of radiological protection to controllable radiation exposure due to natural sources and long-lived radioactive residues

This report provides guidance on the application of the ICRP system of radiological protection to prolonged exposure situations affecting members of the public. It addresses the general application of the Commission's system to the control of prolonged exposures resulting from practices and to the undertaking of interventions in prolonged exposure situations. Additionally, it provides recommendations on generic reference levels for such interventions. The report also considers some specific situations and discusses a number of issues that have been of concern, namely: natural radiation sources that may give rise to high doses; the restoration and rehabilitation of sites where human activities involving radioactive substances have been carried out; the return to 'normality' following an accident that has released radioactive substances to the environment; and the global marketing of commodities for public consumption that contain radioactive substances. Annexes provide some examples of prolonged exposure situations and discuss the radiological protection quantities, radiation-induced health effects and aspects of the Commission's system of radiological protection relevant to prolonged exposure. Quantitative recommendations for prolonged exposures are provided in the report. They must be interpreted with extreme caution; Chapters 4 and 5 stress the upper bound nature of the following values: Generic reference levels for intervention, in terms of existing total annual doses, are given as < approximately 100 mSv, above which intervention is almost always justifiable (situations for which the annual dose threshold for deterministic effects in relevant organs is exceeded will almost always require intervention), and < approximately 10 mSv, below which intervention is not likely to be justifiable (and above which it may be necessary). Intervention exemption levels for commodities, especially building materials, are expressed as an additional annual dose of approximately 1 mSv. The dose limit for exposures of the public from practices is expressed as aggregated (prolonged and transitory) additional annual doses from all relevant practices of 1 mSv. Dose constraints for sources within practices are expressed as an additional annual dose lower than 1 mSv (e.g. of approximately 0.3 mSv), which could be approximately 0.1 mSv for the prolonged exposure component. An exemption level for practices is expressed as an additional annual dose of approximately 0.01 mSv.     

江西省修水县石煤矿区放射性环境调查与评价

石煤的开发和综合利用对环境有可能造成一定的污染,其中影响环境放射性水平增高和居民受照剂量增加等辐射方面的污染问题较为敏感以及突出。本次研究对江西省主要石煤资源区——修水县一处典型石煤矿的放射性环境进行调查,通过多介质采样分析以及现场监测γ辐射空气吸收剂量率和地面γ能谱相结合,综合研究该区放射性核素分布与环境γ剂量率之间的关系,利用公式估算石煤矿区居民辐射剂量并评价其环境辐射情况。结果表明,调查范围内的石煤矿区地面γ辐射空气吸收剂量率的平均值达到了662 nGy/h,该处铀矿主要形式为碳硅泥岩型,区内石煤、石煤渣、土壤、水样放射性核素测量值都高于省内相应介质的本底值,石煤矿的开采需接受专业的监管。     

Survey of radon concentrations in bone-coal mining areas and inside BCCB houses in five provinces

1 Introduction According to the National Investigation of Natu- ral Radioactive Level (abbreviated as “the investiga- tion of levels” below) during 1983-1990, the specific activities of radionuclides in bone-coal are relatively high. It is a man-made activity which may signifi- cantly increase the radioactive level of environment and the public dose, when the local peasants sponta- neously mine the bone-coal, produce bone-coal cinder bricks (BCCB, commonly called as carbide brick) with bo…     

Radioactivity level of the ambient environment of Anren bone—coal power station

The radioactivity level of the ambient environment of Anren Bone-coal Power Station(BCPS) was investigated systematically.The γ radiation dose rate level in the environment ,the content of ^238U and ^226Ra in the ambient soil and the farmland in the direction of downwind,the concentrations of ^238U,^232Th,^226Ra,^40K and ^222Rn,as well as α potential energy in air,and the concentrations of natural U and Th in effluent are all higher than the corresponding values of the reference site.The additional annual effective dose equivalent to the residents living in the houses made of bone-coal cinder brick is 2.7mSv.     

Present status and practical issues on dosimetry for the lens of the eye at JAEA MOX fuel facilities

ABSTRACT

At Japan Atomic Energy Agency (JAEA) MOX fuel facilities, a worker usually wears a protective lead apron; therefore, the dose to the lens of the eye (lens dose) outside the apron is higher than that to the torso. To estimate the potential impact on the current facility operation of the International Commission of Radiological Protection (ICRP)-proposed lens dose limit reduction from 150 mSv/y to average 20 mSv/y, the authors carried out an analysis on the past dose records for the workers over the last 18 years. Of a total of 4,312 workers’ records analyzed, two workers’ annual lens doses exceeded the lowered limit of 20 mSv (23.3 mSv and 20.7 mSv), although the maximum effective dose was below 10 mSv in each case. These compiled dose data reveal that in the glovebox and related operations the lens dose will be a limiting factor in radiological control under the newly lowered dose limit. To ensure that the number of workers with an annual lens dose greater than 15 mSv (approximately 0.6% of the workers) is kept to a minimum, the implementation of an administrative control level for the lens dose is considered.     

中国成年男子摄入原生放射性核素所致内照射剂量估算

本文依据近年来对膳食摄入量和人体器官组织含量研究结果和有关文献进展，采用直接法和间接法估算了我国当前成年男子摄入原生放射性核素(氡与子体除外)所致年待积有效剂量约为O．484mSv，比UNSCEAR世界估算值高约69％；^238u放射系的约为估算值的2．6倍；钍放射系的约为3．6倍。这些差异可归因于我国土壤铀、钍浓度都高于世界均值和特定膳食组成等因素。采用直接法估算40K年有效剂量为O．168Msv，接近于世界估算值(O．165Msv)。^z38U系和^232Th系核素按直接法和间接法估算值分别为O．22mSv和O．3mSv，都比UNSCEAR世界相应估算值高。这些结果为推荐我国天然辐射剂量参考值、我国参考人相应参数和辐射监测背景值提供了有用依据。最后，对我国今后研究提出了一些建议。     

燃料组件修复过程中单根燃料棒损坏影响分析

以核电厂燃料组件修复过程中单根燃料棒损坏释放的放射性物质为分析对象,就放射性物质释放对组件修复的工作人员产生的累积有效剂量进行评估,对向环境释放的气态流出物的放射性总活度进行计算,并对气态流出物排放监测的影响开展分析。分析结果表明单根燃料棒损坏后,执行燃料组件修复的每位工作人员接受的累积有效剂量为12.2 mSv,低于GB 18871—2002规定的工作人员职业照射年平均有效剂量限值20 mSv;向环境释放的气态流出物中惰性气体与碘的放射性总活度分别为3.51×10¹¹ Bq和2.17×10⁸ Bq,远小于GB 6249—2011规定的年排放控制值6.0×10¹⁴ Bq和2.0×10¹⁰ Bq。燃料棒损坏后40 min烟囱排气惰性气体测量仪的读数小于1.0×10¹¹ Bq/h,核电厂无需进入应急待命状态。     

中国核工业三十年辐射环境质量评价

本文主要介绍我国核工业三十年环境辐射影响评价的内容、方法及其主要结果。总的来说,我国核工业对环境的辐射影响是很小的。各单位关键居民组所受剂量均小于5mSv/a;且在关键居民组所受剂量中,有77.1%的单位·年低于0.25mSv/a;核工业对其厂址周围半径80km范围内居民所致的集体有效剂量当量低于天然辐射的万分之一。但矿山、水冶厂产生的集体剂量占整个核燃料循环中总集体剂量的比例较高,达91.5%。     

香港地区土壤和建筑材料中天然放射性水平及天然辐射所致居民剂量估算

本文报道了香港地区土壤、常用建材及路基体中~(238)U、~(226)Ra、~(232)Th 和~(40)K 含量的测量结果,由此估算了空气γ吸收剂量率和室内氡浓度,并且与初步实测值进行了比较。最后估算出天然本底辐射所致香港居民人均年有效剂量当量为3.24 mSv。     

Fission product release and its environment impact for normal reactor operations and for relevant accidents

The radioactive concentration in the primary loop and the radioactive release for both normal operations and accidents for the HTR-10 are calculated and presented in the paper. The coated-particle fuel is used in the HTR-10, which has good performance of retaining fission products. Therefore the radioactive concentration in the primary loop of the HTR-10 is very low, and the amount of radioactive release to the environment is also very small for both normal operation and accident conditions. The radiation doses to the public caused by radioactive release for both normal operations and accidents are given in the paper. The results show that the maximum individual effective dose to the public due to the release of airborne radioactivity during normal operations is only 1.4×10⁻⁴ mSv a⁻¹, which is much lower than the dose limit (1 mSv a⁻¹) stipulated by Chinese National Standard GB8703-86. For depressurization accident and water ingress accident, the maximum individual whole-body doses to man are only 7.7×10⁻² and 2.0×10⁻¹ mSv, thyroid doses only 1.7×10⁻¹ and 1.1 mSv, respectively. They are much lower than the prescribed minimum of emergency intervention level (whole-body dose: 5 mSv, thyroid dose: 50 mSv) for sheltering measures stipulated by the Chinese Nuclear Safety Criterion HAD002/03. The conclusion is that the environmental impact is very small for normal operations and accidents for the HTR-10, and the requirements stipulated in the Chinese Nuclear Safety Criterions are satisfied perfectly.     

Studies of the radiation environment on the Mars surface using the Geant4 toolkit

The radiation environment on the surface of Mars is a potential threat for future manned exploration missions to this planet.In this study,a simple geometrical model was built for simulating the radiation environment on the Mars surface caused by galactic cosmic rays;the model was built and studied using the Geant4 toolkit.The simulation results were compared with the data reported by a radiation assessment detector （RAD）.The simulated spectra of neutrons,photons,protons,a particles,and particle...     

Investigation of environmental activity levels of bone-coal mining area in five provinces

During 1991-1993, the activity levels of the bone-coal mines were investigated in Zhejiang, Hubei. Hunan,Jiangxi and Anhui Province, respectively, where the reserve of bone-coal is about 90% of our country‘s total reserve.The average ofγ radiation doserate level measured for bone-coal, bone-coal cinder (BCC) and bone-coal cinder brick (BCCB) in these provinces is about 500 nGy/h, 400 nGy/h and 700 nGy/h respectively, while that for fields, roads and houses made of BCCB in corresponding regions of these provinces is about 200 nGy/h, 260 nGy/h and 300 nGy/h respectively. It is shown that the environmental activity level of bone-coal mining area is about 3 times higher than the reference spots.     

包头市建筑主体材料天然放射性水平

采用低本底多道NaIγ能谱仪测定了建筑主体材料天然放射性核素40K、232Th和226Ra的比活度,并根据国家标准和欧盟放射卫生防护原则进行分析评价。结果表明,建筑主体材料中40K、232Th和226Ra的放射性比活度分别为218.82 1145.92、19.75 132.50和11.46 82.66 Bq/kg;其内照射指数IRa为0.06 0.41,外照射指数Iγ为0.28 0.70;年有效剂量率为0.41 0.97 mSv/y,内、外照射指数均小于1,本文所采集和测定的建筑主体材料的天然放射性水平都在允许范围内,故可销售和使用。然而,灰渣砖所致的居民的年有效计量率(0.97mSv/y)接近最大允许限值1 mSv/y。因此,应有效地监管建筑材料中工业废渣的用量,避免给居民带来不必要的照射。     

重庆市工业探伤和密封源应用辐射工作人员2006～2008年个人剂量监测

报道重庆市工业探伤和密封源应用辐射工作人员的2006-2008年个人剂量监测结果。监测结果表明：接受监测的辐射工作人员2006-2008年个人年有效剂量范围为0.01-6.77 mSv;工业探伤工作人员个人有效剂量范围为0.01-6.77 mSv,密封源应用工作人员个人年有效剂量范围为0.01-0.54 mSv。     

Radiological impact of transport of radioactive material in UK by road and rail

Abstract

A survey has been carried out on the transport of radioactive materials by road and rail in the UK by the Health Protection Agency's Radiation Protection Division. This survey, carried out in 2004, is the latest in a series of periodic studies on the transport of radioactive materials by all modes of transport. Questionnaires were sent to hospital departments, radionuclide manufacturers, suppliers, and carriers, and to the nuclear and other industries, in order to obtain data on shipments of radioactive materials. Visits were made to hospitals, suppliers, carriers and some railway premises in order to observe working practices and radiological surveys were made while packages were handled. Assessments of individual doses to workers and members of the public were made, and occupational dosimetry data were also obtained. It was found that ～500 000 package movements take place by road annually in the UK, with ～4000 package movements annually by rail. Radiation doses to most transport workers are low, with an average dose of 0·6 mSv to general workers transporting medical and industrial sources. Doses to individual members of the public are very low, with average annual doses of less than 0·02 mSv.     

某医院2019—2021年放射工作人员个人剂量监测结果分析

目的 了解空军军医大学第二附属医院核医学科放射工作人员职业性外照射个人剂量情况。方法 以该院核医学科全体工作人员为研究对象,对其2019—2021年间所受外照射个人剂量进行监测并分析。结果 (1)2019、2020、2021年人均年有效剂量分别为1.04、1.22和1.19 mSv/a,其中,医师为0.85 mSv/a...     

中国核动力院外围空气中7Be、40K、60Co、131I、137Cs分布特征及所致公众年有效剂量评价

基于2015—2017年中国核动力院外围空气中⁷Be、⁴⁰K、⁶⁰Co、¹³¹I、¹³⁷Cs监督性监测数据,对综合楼、南坝工会和木城水厂监测点附近居民组三种途径的有效剂量进行了粗略估算。结果表明:随距核设施距离增加,⁶⁰Co、¹³¹I、¹³⁷Cs平均年摄入量和所致年有效剂量减小;综合楼附近居民组中成人、青少年、儿童、幼儿、婴儿经吸入⁷Be、⁴⁰K、⁶⁰Co、¹³¹I、¹³⁷Cs平均年摄入量分别为29.25、26.48、20.16、11.49、6.79 Bq/a;综合楼附近居民组中青少年、儿童、成人、幼儿、婴儿,经吸入、浸没和地面沉积途径⁶⁰Co、¹³¹I、¹³⁷Cs所致年有效剂量分别为133.58、130.98、128.61、120.20、118.61 nSv/a,⁶⁰Co所致剂量分数达到95.6%,其次是¹³⁷Cs;地面沉积途径所致剂量分数达到54%,其次是吸入;综合楼附近居民组中青少年组成员⁶⁰Co、¹³¹I、¹³⁷Cs所致有效剂量最大为133.58 nSv/a,但此有效剂量也仅占评价剂量目标值(0.25 mSv)的1‰以下。由此可以得出,核基地核设施正常运行工况下,⁶⁰Co、¹³¹I、¹³⁷Cs对核基地外围空气的影响很小。     

我国放射性物质运输概况

本文介绍了我国放射性物质运输概况(除台湾省外)。目前,全国放射性物质货包的年运输最约10万件,总放射性活度为1.8PBq,运输的放射性同位素主要是~(131)I、~(32)P 和~(198)Au 等。承运人员的年剂量当量是相当低的,一般小于5mSv。由于十分重视放射性物质的安全运输,所以没有发生过严重事故。文中还讨论了放射性物质运输中的防护问题。     

Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste. ICRP Publication 81

The present publication deals with the radiological protection of members of the public following the disposal of long-lived solid radioactive waste using the 'concentrate and retain' strategy. It covers options including shallow land burial and deep geological disposal. The recommendations made in this report apply to new disposal facilities.The main protection issue concerns exposure that may or may not occur in the far future, i.e. a situation of potential exposure. Constrained optimisation is the central approach to evaluating the radiological acceptability of a waste disposal system. In this context optimisation of protection is a judgmental process with social and economic factors being taken into account and should be conducted in a structured essentially qualitative way.Two broad categories of exposure situations have to be considered: natural processes and human intrusion. Application of the radiological protection criteria to these two categories of exposure situations is different.In the first case, assessed doses or risks arising from natural processes should be compared with a constraint of no more than about 0.3 mSv per year or its risk equivalent of around 10(-5) per year. With regard to human intrusion, understood here as inadvertent human intrusion, the consequences from one or more plausible stylised scenarios should be considered in order to evaluate the resilience of the repository to such events. The Commission considers that in circumstances where human intrusion could lead to doses to those living around the site sufficiently high that intervention on current criteria would almost always be justified, reasonable efforts should be made at the repository development stage to reduce the probability of human intrusion or to limit its consequences. In this respect, the Commission has previously advised that an existing(1) annual dose of around 10 mSv per year may be used as a generic reference level below which intervention is not likely to be justifiable. Conversely, an existing(1) annual dose of around 100 mSv per year may be used as a generic reference level above which intervention should be considered almost always justifiable. Similar considerations apply in situations where the thresholds for deterministic effects in relevant organs are exceeded.The conclusion of the report is that in the Commission's view, provided reasonable measures have been taken both to satisfy the constraint for natural processes and to reduce the probability or the consequences of inadvertent human intrusion, and technical and managerial principles have been followed, then radiological protection requirements can be considered to have been complied with.