Western European Nuclear Regulators Association Research Articles

International legal regulation of ensuring energy and nuclear security of Ukraine during war

The article examines the issues of international legal regulation of energy and nuclear security of Ukraine in wartime conditions. Peculiarities and problems of normative and legal regulation of energy security of Ukraine in peacetime and martial law are analyzed. The modern conditions of the full-scale war of the Russian Federation against Ukraine on the energy front, where “special operations” are conducted against the energy system, which combines thermal, hydro and nuclear power plants, are investigated. The main areas of ensuring Ukraine's energy and nuclear security in wartime conditions are considered through international legal regulation of energy and nuclear security protection in the world, as well as through the role played by international organizations, which are effective means of global energy security in world nuclear energy. The outlined conceptual provisions and mechanisms for ensuring global nuclear safety are in the field of view of the most influential international organizations such as: International Atomic Energy Agency (IAEA); UN; NATO; Western European Nuclear Regulators Association (WENRA) and EuropeanNuclear Safety Regulators Group (ENSREG); European Nuclear Safety Regulators Group (ENSREG) at the European Commission; Nuclear Energy Agency of the Organization for Economic Cooperation and Development (Nuclear Energy Agency at OECD – NEA/OECD); European Organization for Nuclear Research (CERN); World Association of Nuclear Power Plant Operators (WANO) World Nuclear Association (WNA); European Atomic Forum (Foratom); International project on innovative nuclear reactors and fuel cycles within the framework of the IAEA (INPRO/INPRO); Forum on cooperation of IAEA regulatory bodies (FSRO/RCF). The methodology for ensuring Ukraine's energy and nuclear security in the conditions of a full-scale war is characterized, which must ensure the necessary level of protection of the critical infrastructure of the sovereign state as a whole from obvious and potential internal and external threats, their timely detection, prevention and neutralization, which will guarantee the stable functioning of the energy complex.

Review of Design Extension Conditions Experiments and Analyses for Non-degraded Core

The second generation nuclear power plants were designed and built to withstand without loss to the systems, structures, and components necessary to ensure public health and safety during design basis accidents (DBAs). In the transient and accident analysis the effects of single active failures and operator errors were considered. There are also accident sequences that are possible but were judged to be too unlikely and therefore were not fully considered in the design process of second generation reactors. In that sense, they were considered beyond the scope of design-basis accidents that a nuclear facility must be designed and built to withstand. Such accident sequences have been analysed in the past to fully understand the capability of a design. The requirements to analyse such sequences for existing reactors have been introduced after Fukushima Dai-ichi accident. In 2012 the design extension conditions (DECs) were introduced in the International Atomic Energy Agency (IAEA) requirements for the design of nuclear power plants (NPPs). Western European Nuclear Regulators Association (WENRA) requirements of existing reactors for DEC were introduced in 2014. The purpose of considering DEC is to further improve safety by enhancing the plant’s capability to withstand the conditions generated by accidents that are more severe than DBAs. This concept by IAEA and WENRA (WENRA definition of DEC is consistent with IAEA definition from 2012, in which DEC with prevention of core melt is called DEC A) is not completely new, since some multiple failures have already been considered in the design of existing reactors, for example anticipated transients without scram and station blackout. The research for beyond design basis accidents with non-degraded core (i.e. DEC A) for existing reactors has been already done in 80’s and 90’ of the previous century. The purpose of this paper is to review that research. The tests performed include total loss of feedwater, station blackout, small break without high pressure safety injection, steam generator tube rupture with no high pressure safety injection etc. Besides review of experiments performed on integral test facilities, examples of DEC A tests, which have been analysed at Jožef Stefan Institute using RELAP5 or TRACE computer code in the last three decades, will be presented too.

Safety Method for the Pre-conceptual Phase of Sodium-cooled Fast Reactors

Abstract The ESFR-SMART European project (Contract number: 754501) focuses on the development of innovative safety design options for future Sodium-cooled Fast Reactors (SFRs). The goal of this paper is to show how the Objective Provision Tree (OPT) method, which is part of the Integrated Safety Analysis Methodology (ISAM) developed by Generation IV Forum (GIF), can help in defining safety guidelines for the definition and the study of ESFR-SMART innovative design options. The OPT method provides a view of the implementation of main safety functions in accordance with defence-in-depth principle and has been adapted to ESFR-SMART needs. Guidance for a consistent and homogeneous application has been developed. The method is applied to each safety function with a specific adaptation for the confinement function. Beyond the allocation of the main equipment ensuring the safety functions to the different levels of defence-in-depth, the adapted method proposes a systematic identification of the mechanisms likely to degrade them. Then, safety features to cope with these mechanisms are investigated as well as the potential common cause failures of main equipment belonging to different levels of defence-in-depth. This adapted method allows to study and then to improve the independence between the levels of defence-in-depth as required for future reactors in Europe by Western European Nuclear Regulators' Association (WENRA). The paper provides the outline of guidance for OPT method adaptation to ESFR-SMART project needs, examples of application and main outcomes of the use of the method.

Advanced Technology and Safety Features of VVER-1200 Nuclear Power Plant

AbstractVVER-1200 (AES-2006) reactor is the latest evolution of VVER plant. It meets the advanced technology and the international safety requirements for G III+ nuclear power plants, which were consistent with IAEA International Nuclear Safety Group (INSAG) recommendations. The Russian general safety requirements are also consistent with the safety objectives specified by WENRA (Western European Nuclear Regulators Association) for new nuclear power plants.The VVER-1200 is based on state of art design, which takes into account of Design Extension Conditions (DEC), in accordance with the current IAEA Safety Standards, and Fukushima lessons learned, as;- The inherent safety: based on feedback control processes,- Defense in depth: using successive barriers concept,The main design concept for providing fundamental safety functions are:- Passive systems: to deal with design extension conditions and beyond design basis accidents (BDBA), (e.g., passive SG cooling system, passive containment cooling system), and provide back- up for active safety systems.- Multiple train redundancy: for control systems,- Diversity: the back - up systems for providing the basic safety functions,- Physical separation: all the four trains of safety systems and their control systems are physically separated. Also, the main control room and emergency control room are physically separated.

Signaled and Silenced Aspects of Nuclear Safety: A Critical Evaluation of International Nuclear Safety Thinking

This article provides a critical analysis of safety-related assumptions and practices in international nuclear safety regulation, together with an overview of those aspects of safety that have been either signaled or silenced. The data consist of safety reports from the IAEA, OECD NEA and Western European Nuclear Regulators Association (WENRA), as well as from the national stress tests reports of the United Kingdom and Finland. For theoretical tools, we draw on the concept of a dominant co-operative scheme, and on some parts of Luhmann's Theory of Social Systems. The method is content analysis. We argue that the prevailing thoughts on safety by the international nuclear safety organizations, which are based on the field of engineering sciences' understanding of safety, affected what was learned from the Fukushima Daiichi nuclear accident and the way the stress tests were conducted. Moreover, the learning, even though it is still ongoing, has been constrained by some emphasized aspects of safety, which tend to ignore other relevant aspects of safety. Therefore, the stress tests and teachings from Fukushima failed to provide as many improvements in nuclear safety as could have been possible if a broader analysis of the Fukushima nuclear accident was used.

To Regulate or Not to Regulate: The Conundrum of Taiwan’s Nuclear Power

AFTER THE FUKUSHIMA NUCLEAR DISASTER IN 2011, THE WESTERN European Nuclear Regulators Association (WENRA) and the European Nuclear Safety Regulators Group (ENSREG) jointly developed a Common Comprehensive and Transparent Risk and Safety Assessment, also known as the Stress Test, in May 2011. Taiwan's nuclear regulating agency, the Atomic Energy Council (AEC), requested to participate in the ENSREG peer-reviewed Stress Test in November 2011, which was formally agreed to in January 2013. Following the requirements of the EU Stress Test program, the AEC prepared the Taiwan Stress Test National Report for Nuclear Power Plants in May 2013 (AEC 2013). As part of the transparency requirements, members of nongovernmental organizations were also invited to evaluate the National Report.The general impression of the National Report was that it looked more like a licensee's report than a report from a regulator. The more critical issue was the geological information provided in the National Report. First, the fault lengths near nuclear power plants were much shorter than those the AEC already knew about, as its chair reported to Taiwan's Legislative Yuan on April 17, 2013 (Hsu 2013; Tsai 2013). Distances between nearby faults and the nuclear reactors were either overlooked or excluded from the report. Nevertheless, the AEC maintained that everything in the Taiwan Stress Test National Report was properly prepared according to the Stress Test procedures.It is quite intriguing that Taiwan invited overseas experts to conduct the assessment, but did not provide them with the most up-to-date information at the same time. Meaningful assessments cannot be achieved using incomplete and inaccurate information. One would like to believe that the AEC did understand the importance of nuclear safety and was capable of acting accordingly. It may be that those in charge of the AEC have been trying to manage conflicting roles simultaneously, and apparently achieving nuclear safety was not often high on its list of priorities. For those trained as nuclear engineers, promoting and expanding nuclear power still prevails over safety and waste management issues. Moreover, the culture of secrecy, deceit, and denial established from day one within the secret nuclear program still prevails to this day.I present several examples in this article to illustrate current disquieting conditions in Taiwan. I start by describing the early secret nuclear weapons program in order to help understand the power distribution and the psychology behind the scenes. Next, I describe the devolution to peaceful applications, the fourth nuclear power plant controversy, and its current status and challenges. Thereafter, I outline nuclear waste problems, the discovery of numerous radioactive apartments, the low-level waste storage facilities on Orchid Island, and recent spent fuel reprocessing issues. In the final section of the article I discuss why unfortunate incidents occurred and how Taiwan policymakers can prevent history from repeating itself.Taiwan's Early Nuclear Weapons ProgramThe Israeli Connection and US OppositionThe nuclear weapons program originated in the arms race between the ruling Kuomintang (KMT, Nationalist Party) and China. In March 1962, President Chiang Kai-shek learned from US intelligence images of a nuclear weapons program being undertaken in northwest China. Generalissimo Chiang, not wishing to fall behind the communists, decided to pursue a nuclear weapons program of his own. Taiwan sought help from Israel. Dr. Ernst Bergmann, chair of the Israeli Atomic Energy Commission, in response to an invitation by General Tang Chun-po, paid a secret visit to Taiwan in 1963 and spent three days at Sun Moon Lake Resort with President Chiang and General Tang (Wang 2010).Soon thereafter, a new research institute for nuclear energy, rocket propulsion, and electronics was proposed. In spring 1964, preparations for creating a military-controlled Chung Shan Science Institute (CSSI) were formally announced, with General Tang serving as chair of its preparatory bureau and Dr. …

Westinghouse AP1000 Plant, a Generation III+ Reactor

In a first part, this paper describes the AP1000® pressurized water reactor (PWR) design and how the AP1000 plant fundamental objectives of safety, simplification and standardization were applied throughout the design of the AP1000 plant.The second part of this paper focuses on specific safety and licensing topics: the AP1000 plant robustness for extreme events that may lead to catastrophic loss of infrastructure (such as the event that occurred at Fukushima Dai-ichi in March 2011) and the AP1000 plant compliance with the safety objectives for new plants released by the Western European Nuclear Regulators’ Association (WENRA).

Contribution of European Nuclear Licensees toward Harmonisation of Regulations for Nuclear Installations

Liberalisation of the European energy market has led to the deregulation of electricity generation and supply. More and more nuclear industry and utilities evolve in an international framework. Diversity of national regulations can seriously distort competition. Undoubtedly, harmonizing regulations is the best way of ensuring that the industry can evolve within a stable legal framework. Consequently, European nuclear license holders supported the work of the Western European Nuclear Regulators Association (WENRA) on the harmonization of European safety standards for existing nuclear power plants, as well as for waste and decommissioning.This support led to the creation, within FORATOM, of the ENISS (European Nuclear Installations Safety Standards) Initiative, in May 2005, in Brussels. The principal mission of ENISS is to bring together decisionmakers, operators and specialists from the nuclear industry with national regulators in order to identify and possibly agree upon the scope and substance of harmonized safety standards.ENISS currently represents the nuclear utilities and operating companies from 16 European countries with nuclear power programme. ENISS above all provides the nuclear industry with the platform that it needs to express its views, provides expert input and interacts fully with regulators throughout the harmonization process. ENISS first task has been to present a common industry position with regards to the Safety Reference Levels that WENRA has proposed. By engaging in a constructive debate with WENRA and playing a dynamic role in the process, ENISS also defends the industry’s interests in a proactive way.Another task of ENISS is to strengthen the industry influence in the revision work of the IAEA Safety Standards. In February 2007, the IAEA and ENISS launched their cooperation agreement. ENISS as an NGO is actively involved in the IAEA safety standards revision process in providing comments on draft safety standards, in particular as regards those where the industry has particular competence or interest. Those areas are NPP design and operation, management systems, waste management/treatment, decommissioning and radiation protection with respect to nuclear safety. ENISS send also experts to participate in IAEA drafting groups and attend the meetings of the IAEA Safety Standards Committees (NUSSC, WASSC, and RASSC) as an observer.At the European level, ENISS is also monitoring the work of the European Commission on regulatory issues in the area of nuclear safety, waste management, decommissioning and radiation protection and participate in ENEF groups.