International law obligations for the disposal of Fukushima nuclear-contaminated water under the principles of nuclear safety

The disposal of contaminated water from Japan’s Fukushima nuclear power plant is a significant international nuclear safety issue with considerable cross-border implications.This matter requires compliance not only with the law of the sea but also with the principles of nuclear safety under international law.These principles serve as the overarching tenet of international and China’s domestic nuclear laws,applicable to nuclear facilities and activities.The principle of safety in nuclear activities is fully recognized in international and domestic laws,carrying broad legal binding force.Japan’s discharge of nuclear-contaminated water into the sea violates its obligations under the principle of safety in nuclear activities,including commitments to optimum protection,as low as reasonably practicable,and prevention.The Japanese government and the International Atomic Energy Agency(IAEA)have breached the obligation of optimum protection by restricting the scope of assessments,substituting core concepts,and shielding dissenting views.In the absence of clear radiation standards,they have acted unilaterally without fulfilling the obligation as low as reasonably practicable principle.The discharge of Fukushima nuclear-contaminated water poses an imminent and unpredictable risk to all countries worldwide,including Japanese residents.Japan and the IAEA should fulfill their obligations under international law regarding disposal,adhering to the principles of nuclear safety,including optimum protection,the obligation as low as reasonably practicable,and prevention through multilateral cooperation.Specifically,the obligation to provide optimum protection should be implemented by re-evaluating the most reliable disposal technologies and methods currently available and comprehensively assessing various options.The standard of the obligation as low as reasonably practicable requires that the minimization of negative impacts on human health,livelihoods,and the environment should not be subordinated to considerations of cutting costs and expenses.Multilateral cooperation should be promoted through the establishment of sound multilateral long-term monitoring mechanisms for the discharge of nuclear-contaminated water,notification and consultation obligations,and periodic assessments.These obligations under international law were fulfilled after the accidents at the Three Mile Island and Chernobyl nuclear power plants.The implications of the principles of nuclear safety align with the concept of building a community of shared future for nuclear safety advocated by China.In cases of violations of international law regarding the disposal of nuclear-contaminated water that jeopardize the concept of a community of a shared future for nuclear safety,China can also rely on its own strength to promote the implementation of due obligations through self-help.

Nuclear Safety Functions of ITER Gas Injection System Instrumentation and Control and the Concept Design

The ITER Gas Injection System（GIS） plays an important role on fueling, wall conditioning and distribution for plasma operation. Besides that, to support the safety function of ITER, GIS needs to implement three nuclear safety Instrumentation and Control（I＆C） functions.In this paper, these three functions are introduced with the emphasis on their latest safety classifications. The nuclear I＆C design concept is briefly discussed at the end.

Nuclear Safety Education for Non-nuclear Engineering Students

The new situations were analyzed for nuclear industry development and security. Besides nuclear wars and terrorism, reactor runaway and un-ruled radioactive source are the main nuclear accidents in peacetime. With the active development of the nuclear industry in China, the existing nuclear education system is becoming deficient or defective. Human factors play an important role in nuclear accident prevention and emergency response in the nuclear engineering system, non-nuclear professional staff are often the subject of personnel in most nuclear projects. In order to ensure the sustainable and efficient accord development of nuclear industry, general nuclear education is necessary for correlative non-nuclear professionals, such as technologies, management, safety, culture and ethic. The nuclear safety education should be included into the national education system.

Rough Sets and Nuclear Safety

It is well-known that rough set theory can be applied successfully to rough classification and knowledge discovery. Our work is concerned with finding methods for using rough sets to identify classes in datasets, finding dependencies in relations and discovering rules which are hidden in databases by means of decision tables and algorithm D. We use these methods to analyze and control aspects of nuclear energy generation.

Establishing a mechanism for international cooperation for Fukushima nuclear-contaminated water monitoring

The Japanese government’s unilateral decision to discharge the nuclear-contaminated water from the Fukushima nuclear power plant into the ocean has caused immense nuclear safety risks.Monitoring the unclear contaminated water is a starting point to combat these risks and seek remedies for the rights and interests of all concerned parties.The establishment of a mechanism for international cooperation in this respect is necessary to handle the risks of the Fukushima nuclear-contaminated water and to lay the foundation of a framework for tackling any future disposal of nuclear-contaminated water following Japan’s example.At present,the international legal systems in the spheres of nuclear safety and security,marine environmental protection,and other areas,as well as the questioning of the monitoring reports of the International Atomic Energy Agency(IAEA)by the relevant parties,the monitoring practices of historical nuclear accidents,and numerous radioactivity monitoring mechanisms have provided the institutional and practical basis for constructing such a mechanism.The mechanism can be promoted by the IAEA through its existing mechanisms or be jointly initiated by China,the Russian Federation,the Republic of Korea,the Democratic People’s Republic of Korea,and the Pacific Island countries,among other stakeholders.Specifically,this mechanism should consist of three levels:first,the framework of the basic legal system,including the cooperative principles of national sovereignty,interest-relatedness,and procedural fairness,and the signing of the Framework Convention on the Monitoring of Fukushima’s nuclear-contaminated water and its Optional Protocol;second,the organizational structure and its responsibilities,which may include the Conference of Parties as the decision-making body,the Secretariat as the central coordinating body,and the monitoring committees in various fields as specific implementing agencies;and third,specific administrative arrangements,which involve the standardization of monitoring,the management system of monitoring networks and stations,the rules for monitoring procedures,and the rules for the utilization of the monitoring data,etc.With the urgent need for the scientific and fair monitoring of Fukushima’s nuclear-contaminated water,China,as a stakeholder country,can promote the establishment of such a mechanism for monitoring nuclear-contaminated water through the following paths:①It is necessary to clarify the factors affecting the construction of an international cooperation mechanism for monitoring nuclear-contaminated water so as to ascertain the standpoints of the stakeholders,claims of their interests,contents of their cooperation,and the relevant international relations.②On the basis of existing practices,China should consider improving the monitoring mechanism to cope with the risks of the discharge of Fukushima’s nuclear-contaminated water by formulating targeted policies and systems,setting up specialized monitoring institutions,and establishing a systematic monitoring network system.③This is an effective way for China to actively promote the participation of stakeholders in the construction of an international cooperation mechanism for monitoring nuclear-contaminated water in Fukushima by further innovating the dissemination mechanism to address the risk of Fukushima’s nuclear-contaminated water discharging into the sea and facilitating the identification of issues for international cooperation in monitoring Fukushima’s nuclear-contaminated water based on the concept of a community with a shared future for mankind.

Safety and effective developing nuclear power to realize green and low-carbon development

This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety,environmental protection, enhancement of nuclear power technology, nuclear waste treatment, and disposal, as well as nuclear power plant decommissioning. Based on the safety record and situation of the existing power plants in China, the current status of the development of world nuclear power technology, and the features of the independently designed advanced power plants in China, this paper aims to demonstrate the safety of nuclear power. A nuclear power plant will not cause harm either to the environment and nor to the public according to the real data of radioactivity release, which are obtained from an operational nuclear plant. The development of nuclear power technology can enhance the safety of nuclear power. Further, this paper discusses issues related to the nuclear fuel cycle, the treatment, and disposal strategies of nuclear waste, and the decommissioning of a nuclear power plant, all of which are issues of public concern.

Reflections on nuclear safety culture from the perspective of traditional Chinese culture

Nuclear safety is a major concern given the rapid development of nuclear power in the modern era.Fostering a nuclear safety culture is an important means of ensuring nuclear safety.In China,a country with a rich historical and cultural heritage,traditional culture will influence the development of a nuclear safety culture.This study explored the origin and levels of nuclear safety culture and reflected on nuclear safety culture from the perspective of traditional Chinese culture.The purpose of this study is to integrate the essence of traditional culture into the nuclear safety culture and foster a nuclear safety culture with Chinese characteristics.

Ensuring Nuclear Safety

The Fukushima accident precipitates overall safety inspection by China Guangdong Nuclear Power Holding Corp The Fukushima nuclear accident in Japan had barely made headlines around the world when China Guangdong Nuclear Power Holding Corp.(CGNPC),a nuclear power magnate in China。

Status of Severe Accident Management Guidelines at Kozloduy Nuclear Power Plant

The objective of this paper is to present the current organization of the Emergency Procedures including Emergency Operating Procedures (EOP) and Severe Accident Management Guidelines (SAMG) in Kozloduy Nuclear Power Plant (KNPP) as a function of the severity of the accident conditions. Special attention is paid to SAMG. It is described when the SAMG are used and at which conditions in a transition between the EOPs and the SAMG should be made. The Critical Safety Function Restoration Guidelines and their connections with SAMGs and EOPs are also discussed. The arrangement of SAMG is described in detail, since in the KNPP exist 2 types of SAMGs for Main Control Room (MCR) and for the Accident Management Centre (AMC) and they contain the same strategies, but they are different in format. Both types are symptom oriented procedures, but those for MCR are in 2-column-format with interconnections, whereas those for the AMC are developed in a logical manner and simplified for people, who take decisions. In the paper, they are also discussed the adopted strategies in existing SAMG that should be followed to recover from a damaged core condition and to prevent or mitigate the release of fission products. In the paper, they are also described a number of technical measures for management and mitigation of severe accidents, which are implemented in KNPP before and after the Fukushima accident. Many of them are common for WWER-1000 type of reactors, but some of them are unique and plant specific. This information can be useful for operators of other WWER type reactors or even PWR reactors.

Assessment of Axial Power Peaking Factors in GHARR-1 LEU Core: A Decadal Simulation Analysis

This study aims to thoroughly investigate the axial power peaking factors (PPF) within the low-enriched uranium (LEU) core of the Ghana Research Reactor-1 (GHARR-1). This study uses advanced simulation tools, like the MCNPX code for analysing neutron behavior and the PARET/ANL code for understanding power variations, to get a clearer picture of the reactor’s performance. The analysis covers the initial six years of GHARR-1’s operation and includes projections for its whole 60-year lifespan. We closely observed the patterns of both the highest and average PPFs at 21 axial nodes, with measurements taken every ten years. The findings of this study reveal important patterns in power distribution within the core, which are essential for improving the safety regulations and fuel management techniques of the reactor. We provide a meticulous approach, extensive data, and an analysis of the findings, highlighting the significance of continuous monitoring and analysis for proactive management of nuclear reactors. The findings of this study not only enhance our comprehension of nuclear reactor safety but also carry significant ramifications for sustainable energy progress in Ghana and the wider global context. Nuclear engineering is essential in tackling global concerns, such as the demand for clean and dependable energy sources. Research on optimising nuclear reactors, particularly in terms of safety and efficiency, is crucial for the ongoing advancement and acceptance of nuclear energy.

Modeling of Operators' Workload in a Nuclear Power Plant

Accidents in a nuclear power plant are coped with by operators in the main control room (MCR). An analysis of the workload of operators in a MCR after the happening of initiating events is helpful to the alleviation of human errors and to the promotion of training efficiency. This paper establishes a framework of how man is located in a man-machine interface of a nuclear power plant (NPP) as well as a simulation of the man-machine scenario in accidents in NPPs, including the simulation of the operators' task and cognitive work and the establishment of task analysis. On the basis of the above, a model of the dynamic changes of the operators' tasks is constructed and a computation of operators' workload is conducted.

Towards Safer and More Sustainable Ways for Exploiting Nuclear Power

Future electricity systems are challenged by deep decarbonization and concurrently increasing demand and there are growing concerns that renewables cannot shoulder this alone. Starting from the proven principle of diversity, we argue for keeping the nuclear option open or even for expanding its use. However, the perspectives are dim for the current technology as safety concerns and social aversion remain as fundamental problems. While looking for future revolutionary safe and more sustainable nuclear concepts we first review the main characteristics of civil nuclear energy, as well as its safety records and technical progress. We then list the key requirements for innovative nuclear systems designs which are less dependent on active safety systems and human performance as well as social stability. This allows us to provide a concept by concept comparison and assessment of existing and novel technologies and designs including different coolants and neutron spectra. The results indicate a high potential for far-reaching improvements compared to most advanced LWRs, although none of the candidate concepts meets all requirements convincingly, yet, helium cooled, small modular reactors (HTR-PM) come closest. We end by stressing the need for future research and development, and keeping human capital and know-how in nuclear energy;we call for an urgent increase in government and international RD&D funding by the order of a few hundreds of billions of USD per year, which will likely lead to breakthroughs that will restart productivity growth in severely affected stagnating modern economies.

A Study on the Public Perception in Nuclear Area in Brazil

During the course of the last years the need for the increase in the electric energy production in Brazil as well as in the rest of the world, has raised the tone of the debate about the environment impact of such production. As a result of these debates, both the several levels of government and some of the NGOs （Non-Governmental Organizations） have commissioned innumerous opinion researches aiming at measuring and evaluating the knowledge and perception of the public in relation of the best non-polluting energy sources. Prior to 2001 these researches would not make any sense in Brazil., however due to that year＇s drought, the competent authorities were faced with the necessity of developing a plan, the PNE2030 （Piano Nacional de Energia） aiming, among others objectives, at finalizing the construction of the Angra three plants and implementing new nuclear plants in places still to be determined. Allowing for the complexity of the subject, this paper presents a field research conducted from September 28th, 2010 to October 28th, 2010 assessing the current level of perception of the Brazilian population about the nuclear area, in particular of the residents of three cities of Rio de Janeiro. As a result of this work, the authors suggest how the competent authorities should proceed to reach in an efficient manner a greater understanding of the population about the proposed subject, through communication campaigns being both informative and educational.

Components Qualification for the Safe Operation of Nuclear Power Plants

AREVA operates a world-wide unique thermal hydraulic platform to ensure high safety standards in the nuclear industries. This platform is operated as an accredited test and inspection body according to ISO 17025 and 17020 to grant a high and independently confmned quality standard. The accreditation also ensures the independency of the organization and confidentiality to the individual stakeholders, for example research centers, utilities, components suppliers, engineering companies and vendors. Especially for nuclear power plants, it is very relevant to consider that reliability depends on the integrity of its components during its life time-from design through construction, operation and maintenance. For example, a typical NPP （nuclear power plant） has 1,000 to 2,000 large valves and 7,500 to 12,500 small valves, of which about 200 to 400 are designated Safety Class 1. The qualification of these Safety Class 1 components is relevant for reactor new builds but also for installed plants. This paper explains newly established qualification tasks, the corresponding testing infrastructure, and the state of the art of testing technology. By way of example, the paper describes the program and possible sequence of qualifying NPP safety-related components.

中法关于核能与环境的联合研究

本文聚焦核能的环境影响问题,将解决如下核能发电相关的主要环境问题:(1)控制正常运行条件下核设施的放射性排放,评估其非放射性环境影响(取水与非放射性水的排放);(2)乏燃料与放射性废物的长期管理,主要是通过地质处置库处理的乏燃料或放射性废物;(3)防止和缓解严重核事故以及核事故的放射性释放;(4)改善核安全水平,以限制核能的环境影响,提升公众的核能接受度。核能的温室气体排放水平非常低,可以根据需求供应大规模、可调度电力,在此方面核能具有独特的优势。在正常运行工况下,核电站每年释放到周围公众的有效辐射剂量可以忽略不计。国际社会已经开展了大量的努力,以确定可持续管理地质处置条件下高放长寿命放射性废物的方法。过去几次严重核事故中获得的经验为核能生产相关的安全问题提供了经验,也促成了重要的安全改进,其中包括反应堆的设计和运行管理方面的改善以及事故管理指导方针的制定等。事实证明,这些经验是非常宝贵的。严重事故的环境风险已经被大幅降低,相关的规约也已经建立起来,以最大限度地减少严重核事故条件下放射性物质的释放,并避免大规模的人员疏散。还需要继续采取措施,改善反应堆的安全性,提升核工业与核监管机构的透明度,以进一步降低核能的环境影响。

Fast nuclide identification based on a sequential Bayesian method

The rapid identification of radioactive substances in public areas is crucial.However,traditional nuclide identification methods only consider information regarding the full energy peaks of the gamma-ray spectrum and require long recording times,which lead to long response times.In this paper,a novel identification method using the event mode sequence(EMS)information of target radionuclides is proposed.The EMS of a target radionuclide and natural background radiation were established as two different probabilistic models and a decision function based on Bayesian inference and sequential testing was constructed.The proposed detection scheme individually processes each photon.When a photon is detected and accepted,the corresponding posterior probability distribution parameters are estimated using Bayesian inference and the decision function is updated.Then,value of the decision function is compared to preset detection thresholds to obtain a detection result.Experiments on different target radionuclides(137Cs and 60Co)were performed.The count rates of the regions of interest(ROI)in the backgrounds between[651,671],[1154,1186],and[1310,1350]keV were 2.35,5.14,and 0.57 CPS,respectively.The experimental results demonstrate that the average detection time was 6.0 s for 60Co(with an activity of 80400 Bq)at a distance of 60 cm from the detector.The average detection time was 7 s for 137Cs(with an activity of 131000 Bq)at a distance of 90 cm from the detector.The results demonstrate that the proposed method can detect radioactive substances with low activity.

Activation characteristics of candidate structural materials for a near-term Indian fusion reactor and the impact of their impurities on design considerations

Activation analyses play a vital role in nuclear reactor design.Activation analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance strategies.Activation analyses also help in the selection of materials for a nuclear reactor,by providing the radioactivity and dose rate levels after irradiation.This information is important to help define maintenance activity for different parts of the reactor,and to plan decommissioning and radioactive waste disposal strategies.The study of activation analyses of candidate structural materials for near-term fusion reactors or ITER is equally essential,due to the presence of a highenergy neutron environment which makes decisive demands on material selection.This study comprises two parts; in the first part the activation characteristics,in a fusion radiation environment,of several elements which are widely present in structural materials,are studied.It reveals that the presence of a few specific elements in a material can diminish its feasibility for use in the nuclear environment.The second part of the study concentrates on activation analyses of candidate structural materials for near-term fusion reactors and their comparison in fusion radiation conditions.The structural materials selected for this study,i.e.India-specific Reduced Activation Ferritic-Martensitic steel（IN-RAFMS）,P91-grade steel,stainless steel 316 LN ITER-grade（SS-316 LN-IG）,stainless steel 316 L and stainless steel 304,are candidates for use in ITER either in vessel components or test blanket systems.Tungsten is also included in this study because of its use for ITER plasma-facing components.The study is carried out using the reference parameters of the ITER fusion reactor.The activation characteristics of the materials are assessed considering the irradiation at an ITER equatorial port.The presence of elements like Nb,Mo,Co and Ta in a structural material enhance the activity level as well as the dose level,which has an impact on design considerations.IN-RAFMS was shown to be a more effective low-activation material than SS-316 LN-IG.

Secondary and activated X(γ)radiation of SPHIC particle therapy facility

We report the secondary X(γ)radiation from the accelerator in a normal operating state and activated X(γ)radiation from the accelerator devices when the accelerator stops operating in the cancer treatment facility of the Shanghai Proton and Heavy Ion Center(SPHIC).These radiation measurements show us the structural radiation distribution along the beam lines and devices inside the accelerator room when the beam is on and off and can support the radiation protection design of the accelerator facility used for cancer treatment and help evaluate the accumulated radiation dose in the case of an emergency,such as a personal safety system failure or a radiation accident.The radiation dose rate measured in this facility shows that the facility is safe from the radiation protection point.After shooting the quality assurance(QA)beam,the radiation dose rate in the treatment room was also measured to investigate the radiation dose space distribution and decay time dependence.In addition,the time period before safely entering the treatment room after determining the shooting of the QA beam is recommended to be approximately 5 min.

An old issue and a new challenge for nuclear reactor safety

Nuclear reactor safety(NRS)and the branch accident analysis(AA)constitute proven technologies:these are based on,among the other things,long lasting research and operational experience in the area of water cooled nuclear reactors(WCNR).Large break loss of coolant accident(LBLOCA)has been,so far,the orienting scenario within AA and a basis for the design of reactors.An incomplete vision for those technologies during the last few years is as follows:Progress in fundamentals was stagnant,namely in those countries where the WCNR were designed.Weaknesses became evident,noticeably in relation to nuclear fuel under high burn-up.Best estimate plus uncertainty(BEPU)techniques were perfected and available for application.Electronic and informatics systems were in extensive use and their impact in case of accident becomes more and more un-checked(however,quite irrelevant in case of LBLOCA).The time delay between technological discoveries and applications was becoming longer.The present paper deals with the LBLOCA that is inserted into the above context.Key conclusion is that regulations need suitable modification,rather than lowering the importance and the role of LBLOCA.Moreover,strengths of emergency core cooling system(ECCS)and containment need a tight link.

RETHINKING NUCLEAR POWER SAFETY

The Fukushima nuclear accident sounds alarm bells in China’s nuclear power industry In the wake of the Fukushima nucleara ccident caused by the earthquake andt sunami in Japan,the safety of nuclearp ower plants and the development of nuclear power have raised concerns,