γ-γ法的理论基础及其应用——对“关于γ-γ密度计问题”和“利用γ

一、引言自1959年以来,在“原子能科学技术”上已先后发表了曾繁超、李业彬和刘雨人等提出的三篇关于γ-γ法问题的文章。从这些文章里可以看出,近年来γ-γ法在我国生产实践上的应用已有相当成绩,而且对γ-γ法的具体应用也有了新的发展。但是也不能否认,γ-γ法在实际应用上还存在一些重要问题,许多作者对这些问题的看法也还存在一些分歧,这就需要今后对该法继续进行深入的研究。这里,笔者仅在力所能及的范围内提出下列几个问题,和大家讨论。     

洁净核能系统中的复杂性与束晕—混沌的控制

在原子能科学技术领域,历来广泛存在十分复杂的各种问题。例如,热核聚变及其高温等离子体是当今最复杂物理和工程问题之一,各种复杂性（包括分岔、混沌和湍流）无所不在。经几代科学家和工程师等的努力,已取得了重大进展,原理性问题已经证明,但还没有达到或解决可利用的商业发电的程度,根据估计,可能要推迟到新世纪的后半叶。因此,从裂变能的商业应用到聚变能的商业应用是一个相当长的时期,估计裂变能的商业应用还有近百年的“独占”地位。目前,核裂变能仍然是核电主要发展方向。但核裂变能还存在一些     

美国关于核废物管理国际合作的基本考虑

确保乏燃料与放射性废物安全的最终责任应由国家承担。最新的动向是，在乏燃料和放射性废物的安全有效管理方面有了进展，即通过国家间的协议，使一国设施的应用能分惠于其他国家。总的说来。美国赞成一个地区内的各国携起手来共同解决其核废物问题，尽管关于区域处置库的任何提案均必须对其自身优缺点进行逐一评价。国际原子能机构(IAEA)和《乏燃料管理安全与放射性废物安全公约》建立了放射性废物和乏燃料转移的有关技术规范，但还存在一些政治上的考虑，而这些考虑最终还必须由国家来决策。     

系统培训方法（SAT）在秦山核电厂的应用

系统培训方法是核电厂人员培训之有效的方法，本文介绍了其主要特点和它在秦山核电厂人员培训方面的应用情况。文章还提出了在应用该方法时值得认真研究的几个问题。     

^252Cf自发裂变中^114Pd累计裂变产额测定及质量分布轻峰…

应用放化法首次测量了＾２５２Ｃｆ自发裂变中＾１１４Ｐｄ的累计裂变产额，其值为（２．５０±０．１１）％。为了解决有关＾２５２Ｃｆ自发裂变质量分布精细结构方面存在的分歧，还测定敢＾１１２Ｐｄ和１１３Ａｇ＾ｇ的累计产额，并应用最新的核参数对献中其它作的数据进行了重新处理和评价。结果表明，在质量分布Ａ－１１３处存在精细结构。     

核电厂一回路源项和排放源项框架体系研究

我国核电机组堆型众多,来源广泛,这些引进堆型的源项在我国应用中还存在一些问题。源项设计是否合理,直接影响到排放源项的准确性和环境影响评价源项的合理性。本文通过分析不同堆型源项在我国应用中存在的问题,研究如何构建我国核电厂通用的一回路源项和排放源项框架体系,为解决国内核电厂源项计算中长期存在的问题,也为我国华龙一号和CAP1400堆型的源项计算提供技术基础。     

我国核技术和放射性同位素应用中几个辐射防护问题的讨论

本文简述了我国核技术和放射性同位素应用中的辐射防护状况,笔者认为,与有关《标准》和先进国家相比,我国在辐射防护方面还存在较多的问题。诸如职业性受照剂量较高、监测不健全、管理不严格等。建议迅速采取管理措施和技术措施,以减少事故发生,使这项应用技术获得更大效益。     

从设计和安审角度看核电厂实体保卫系统

本文从设计和安审角度对我国目前核电厂实体保卫系统存在的问题进行了简要论述，提出了核电厂实体保卫系统还需要正规化、系统化，标准化。     

关于ICRU39号报告中的辐射量的讨论

本文介绍了 ICRU39号报告中提出的用于场所监测和个人剂量监测的四个辐射量的概念和特性,分析了它与以往的用剂量当量指数量方案的差别和改进之处,指出了它在实用中还存在的一些困难和应用中尚须注意的问题。     

高频交流电子镇流技术发展与应用

本文主要讨论了高频交流电子镇流技术的发展，应用、典型电路、存在问题及发展方向，介绍了典型应用集成电路和相关设计软件。     

拟将颁布的国际基本安全标准（BSS）中的豁免值的推导条件

各种豁免值都是根据一定的假设条件（适当偏保守）推导出来的，由于国情可具体假设条件不同，推出的豁免值及其应用范围也将不同，因此为了防止误用，豁免也是要求经过审批的，本文扼要介绍了已经过７稿修改可能会在近期内颁布的国际基本安全标准所列豁免值的推导用假设条件，以利于对这些豁免值的正确理解的应用，虽然ＢＳＳ将来正式颁布时，某些地方还可能会有某些修改，但估计本文涉及的内容不会有原则变动。     

Practical judgment of exemption by applying isotope specific exemption levels for surface contamination

Abstract

In terms of applying the concept of exemption to safety standards for surface contamination, we have derived isotope specific exemption levels for surface contamination (Bq cm^–2) by developing an original dose assessment model for surface contamination to develop reasonable radiation protection systems that reflect the radiological properties of nuclides and avoid excessive regulatory procedures. These exemption levels can be applied to the radiation, waste and transport safety fields by assuming a universal scenario and by applying radiation protection systems consistent with the current International Atomic Energy Agency (IAEA) Basic Safety Standards, safety series no. 115 and safety guide RS-G-1·7. In the case of materials containing a mixture of nuclides, the exemption can generally be judged on the basis of whether the condition ΣD/C<1 is satisfied (where D represents an actual measurement result and C represents the exemption level), and the estimation of the surface contamination density of key nuclides such as ⁶⁰Co, which are easily measured and dominant nuclide components, can be practically applied to the judgment of exemption. In this study, the contribution of nuclides to the summation defined in terms of relative importance was assessed using the exemption levels for surface contamination derived in previous Central Research Institute of Electric Power Industry (CRIEPI) studies and the technical data of nuclide composition ratios contributing to contamination assumed to occur in Japanese nuclear power plants. Important nuclides, whose relative importance was >0·1, were extracted following the 10% summation rule described by the European Commission in its document Radiation Protection 134. It was found that ⁶⁰Co was the only important nuclide in most of the cases and other nuclides can be ignored according to the reasonable exemption levels for surface contamination derived in CRIEPI's previous study, where the α emitter was the most important nuclide in the case of estimating fuel damage by applying the exemption levels for surface contamination derived from the dose conversion factors given in IAEA TECDOC-1449. It is expected that the resulting reasonable exemption levels for surface contamination will be applied practically to future regulation and that consistent radiation protection systems will then be realised throughout the radiation, waste and transport safety fields.     

Transport of low-level NORM – a case for consistency and practicality

Abstract

In 1996 the International Atomic Energy Agency (IAEA) adopted a system for exemption of lowlevel radioactive material from transport regulations based on the principle that exemption values should be commensurate with the risk posed by the material as represented by the maximum potential radiation dose to individuals. For many naturally occurring radionuclides the derived dose-based, radionuclide-specific exemption concentrations were substantially lower than the previous radionuclide-independent definition of radioactive material (70 Bq g^–1) [1900 pCi g^–1] due to the stringent dose criterion applied. It was recognised that this would bring large quantities of previously unregulated naturally occurring radioactive material (NORM) handled in industry into the scope of the transport regulations. To minimise the economic impact of the dose-based values, a special provision was included to provide for a 10-fold increase in exemption values for radionuclides in natural material provided the material is not intended to be, and has not previously been, processed for recovery of its radionuclides (the wording regarding previous use was added in 2003). This '10 times' or '10×' provision for certain natural material reflects a second concept underlying IAEA guidance, namely, that a dose criterion may be relaxed within cautious bounds to achieve a balance between practical issues and radiological concerns. On the other hand, restriction of the provision on the basis of past or intended use of the material is inconsistent with the basic principle underlying the Transport Regulations in that there is no risk basis for assigning different exemption values to identical materials on the basis of their past or anticipated use. In fact, the same material can move in and out of the scope of regulatory control as its anticipated use changes. As a practical matter, safety guidelines for potentially hazardous material should be based on measurable properties of the material and not the whims of human intentions. To improve the practicality as well as the consistency of the Transport Regulations as applied to NORM, the 10× provision should be revised to apply to all natural materials, regardless of their intended use.     

辐射防护新概念对放射性废物管理的启发意义

本文通过对源项、途径、剂量、效应的讨论，进一步明确放射性废物管理的地位和作用；通过对实践、干预、豁免和潜在照射的讨论，增强在放射性废物管理中正确使用辐射防护原则的认识；通过对市管体系、现场防护体系、事故应急体系的讨论，促进国际放射防护委员会的建议在放射性废物管理中的实施。     

Scope of radiological protection control measures

In this report, the Commission recommends approaches to national authorities for their definition of the scope of radiological protection control measures through regulations, by using its principles of justification and optimisation. The report provides advice for deciding the radiation exposure situations that should be covered by the relevant regulations because their regulatory control can be justified, and, conversely, those that may be considered for exclusion from the regulations because their regulatory control is deemed to be unamenable and unjustified. It also provides advice on the situations resulting from regulated circumstances but which may be considered by regulators for exemption from complying with specific requirements because the application of these requirements is unwarranted and exemption is the optimum option. Thus, the report describes exclusion criteria for defining the scope of radiological protection regulations, exemption criteria for planned exposure situations, and the application of these concepts in emergency exposure situations and in existing exposure situations. The report also addresses specific exposure situations such as exposure to low-energy or low-intensity adventitious radiation, cosmic radiation, naturally occurring radioactive materials, radon, commodities, and low-level radioactive waste. The quantitative criteria in the report are intended only as generic suggestions to regulators for defining the regulatory scope, in the understanding that the definitive boundaries for establishing the situations that can be or need to be regulated will depend on national approaches.     

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.     

当前我国含放射性物质消费品辐射安全监管探讨

本文针对含放射性物质消费品的监管现状,对我国现行法规和标准进行了梳理和解读,对此类消费品的正当性、豁免管理、监管机构职责、法规与标准、监测与评估等方面存在的问题进行了讨论,提出了改善这类消费品辐射安全监督管理的建议。     

清洁解控和退役若干动向与新发展

对国际辐射防护协会第 1 0届大会 ( IRPA-1 0 )涉及的清洁解控和退役问题作了论述 ,包括排除、豁免、清洁解控和废物最少化 ;退役工程技术的发展 ,包括去污技术、切割解体技术、探测技术 ;介绍了一个研究堆退役例子和加速器退役 ;最后 ,还论及了退役中受关注的一些问题 ,如 :石墨废物、混凝土废物、重水堆退役的氚防护、退役时间和退役废物量等。     

放射性废物安全的主题分类和部分成果评介

将放射性废物安全初步分类为废物处理与整备设施安全,废物贮存设施安全,废物与废放射源处置设施安全,流出物排放安全,污染物料回收利用安全,退役与环境整治安全,排除、豁免、解控,废物优化管理和废物最少化,废物管理政策法规标准和规划,废物安全监管和安全文化素养等10个主题.按照上述主题分类,对我国放射性废物安全领域近年来的研发进展做了述评.     

轻微放射性污染金属再循环再利用中的剂量评价

根据GB18871—2002所规定的豁免剂量准则和国际原子能机构所推荐的相关方法,对钢铁、铝、镍和铜4种轻微放射性污染金属的再循环再利用中的剂量评价方法作了介绍。所得计算结果合理可信,已作为修订相关国家标准的基础。保护环境和实现再循环经济是我国科学发展的基本国策,标准颁布后可发挥很好的社会效益和经济效益。