[en] Full text: First we present EDF Group nuclear safety policy. Then, after an overview of the EDF SA nuclear fleet and of its Management of safety, we present the verification line: an in-house independent nuclear safety assessment function put in place at power station level, Company level, and Group level. Lastly, after a short presentation of human resources management and corporate communication on safety, we develop EDF policy about international peer reviews. (author)

[en] Full text: WANO international Peer Reviews aim to help members compare their operational performance against their standards of excellence through in-depth, objective operational reviews by an independent team from outside their utility. These reviews are important because as we all know, peer judgment is an excellent and perhaps unique means of improving ourselves both as single plants and utilities but also collectively. Since the Fukushima severe accident in 2011, international peer reviews have become even more important. At the WANO board level we have revisited the Peer Review framework and the way we use them with our members and also outside our own organization. I believe this session will enable the audience to understand what we have tried to achieve and what we have accomplished so far. (author)

[en] Full text: Full text: Safe restart of nuclear power plants in Japan is now the primary concern of the Japanese nuclear power operating companies. At the same time, the Nuclear Regulation Authority of Japan (NRA) has stated that “ we will be tireless in our efforts to improve our regulatory measures so that Japan's nuclear regulation standards will be among the world's highest.” The new regulations are a challenge to the operating companies, involving new analyses and, in many cases, costly back-fits. This paper will discuss our direct experience working with several operating companies in Japan to help make the reactors safe for operation under the new regulations. We believe that our work in Japan will be of great interest to the nuclear operating companies of other countries, as well as the methods and techniques we use to ensure nuclear safety. Our main activities are centered on fire protection analysis and safe shutdown; capable fault analysis; probabilistic fault displacement analysis (PFDHA); tornado hazard analysis; plant process computers for emergency control rooms, and probabilistic risk assessments (PRA) to measure the effectiveness of changes to the operating plants. We have performed fire protection analyses at the Sendai NPP and the Genkai NPP for Kyushu Electric Power Company; the Shimane NPP for Hokuriku Electric Power Company; and we are now beginning the same type of analysis for the Tsuruga NPP for the Japan Atomic Power company. The NRA has approved our work at the Sendai NPP and given their approval for the Sendai restart. In several cases we were able to show that costly replacement of cables was not necessary. While tornados in Japan are rare, the new regulations stipulate that tornado hazards must be considered. We have done a tornado hazard assessment at the Genkai NPP. The new NRA regulations for declaring a fault capable are quite stringent: the operating companies must show that there has been no movement on a fault for the last 120,000 – 130,000 years. We have put together international teams with acknowledged experts in geology, seismology, and PRA and done detailed analyses at the Higashidori NPP for Tohoku EPCo and the Tsuruga NPP. While PFDHA is not required under the new regulations, we are now doing a PFDHA at the Tsuruga NPP to consider movements of the Urasoko fault and subsequent sympathetic movement of the D1 crush zone. While not directly related to restart, our plant process computer installed at Fukushima Daiichi Unit 2 survived the earthquake and tsunami on 3.11.11 and is still be used to monitor the reactor in its shutdown state. Because of the proven hardness of our installation, we are now in discussions with operating companies for use in the required emergency control rooms. This paper will review our work with an emphasis on methodology and techniques and their effectiveness in increasing safety. (author)

[en] After the accident at the Fukushima Daichi nuclear power plant, the stability of nuclear power plants against external influences were tested all around the world with stress tests, and it was declared that a high level of operational safety had been reached, in accordance with “international standards.” However, given the experience of two accidents - the Armenian power plant in 1982 and Chernobyl in 1986 (in the aftermath of which the author took part) - we shouldn’t declare such things with confidence because there remain hidden, internal factors that are outside the field of view that don’t lend themselves to being known before a specific situation, and because some documents such as “Probability Safety Analysis” or “Safety Analysis Report” haven’t been taken into account. Many of these hidden factors could be discovered safely if performed at the modular/block level with In-core Monitoring Systems (IcMS), with early forecasting and detection of anomalies in the technical process of the reactor station. For this, it’s necessary to raise its status and quality; above all, it’s in formativeness, the reliability of metrological characteristics, and the stability of its mathematical software. In this sense, as was shown by an analysis, the majority of stationary In-core Monitoring Systems are based on neutron (for example, rhodium Rh-103) detectors that don’t meet today’s requirements for any of these indicators. The root cause of this failure is the need to account for burnout processes, neutron flux depression, and the change in the spectrum of neutrons. Accounting for these requires regular recalibration of integral balance reactor indicators and the existence in stationary In-core Monitoring Systems of interprocess communications with cumbersome computational operations. All of which can result in the failure of a stationary system to provide the information needed to avoid a crisis. In order to achieve the above-mentioned level of control (in-core monitoring), a new concept was introduced by us, and in 1985 an IcMS system project was conducted on the second block of the Armenian nuclear power plant, the physics of which were based on monitoring the gamma-field of the core, and on calorimetric gamma-detectors developed as primary incore sensors. The theoretical and experimental results of this project were presented in a report, including: — The concept and principles for building the system; — The construction of gamma-detectors and measurement channels (probes); — A description of physical processes and control algorithms; — The results of metrological, operational and resource/endurance tests; — The results of system control algorithms and programs in general.

[en] Full text: As part of the evaluation of national and international operating experience, for events with safety significance for other plants GRS prepares German Information Notices by order of the BMUB (German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety). In these, the facts of the event are described, the cause of the event is identified and GRS assesses the safety significance of the event to the German nuclear power plants (NPPs). Based on these assessments, GRS gives recommendations to prevent similar events in German NPPs. The Information Notices are distributed to the nuclear supervisory authorities, the operators of NPPs and research reactors, the Technical Inspection Authorities and to component manufacturers. In response to the Information Notices GRS receives a plant-specific feedback about the measures taken by the German NPPs. This feedback is evaluated by GRS to gain further experience and to make this available to the supervisory authorities and the BMUB. In the aftermath of the Fukushima Daiichi Nuclear Power Station accident, GRS was requested by the BMUB to analyse the events in Fukushima for potential applicability to German NPPs and to prepare an Information Notice. GRS has written an Information Notice with recommendations derived from the events in Fukushima. In the regime of electrical power supply, these include mobile diesel generators with corresponding, redundant feeding points, an enhanced coping time for station blackouts with only DC-power left and measures to ensure restarting AC-power within the coping time. In this presentation the authors give an overview over the recommendations given in the Information Notice concerning the Fukushima accident and the retrofitting activities which took place at exemplary German NPPs to fulfil the given recommendations in order to enhance the robustness of them. (author)

[en] In compliance with the requirements of the Russian regulations in the field of nuclear energy use, the Beyond- Design-Basis Accidents Management Guide shall be developed for every NPP unit. Following the results of the stress-tests of the Russian NPPs carried out upon Fukushima-Daiichi NPP accident , the development of a Safely Guide by the regulatory authority was recognized as expedient to establish recommendations to the structure and content of u Beyond-Design-Basis Accidents Management Guide. The Safety Guide that has been drafted for two years covers both the accident management issues at the stage of severe core damage prevention, and at the stage of severe accident progression. One of the key issues to be solved in the course of the Safety Guide drafting was the synergy of the knowledge-based approach and the approach based 011 the beyond-design-basis accident management rules. As is welt-known, most actions shall be implemented within a limited time period, and-availability of a step-by-step procedure for such actions implementation may significantly facilitate the challenge of timely accomplishment of the required actions. On the other hand, if personnel follow the prescribed step-by-step procedures without deep insight into the accident processes, there is a risk to face a situation of ''trampling on-the spot'' or ''circle-wise wandering'', in case there occurs an unforeseen emergency situation, when the proposed step-by-step procedures will not allow to manage the accident effectively and recover the controlled steady state of a nuclear power plant.

[en] Full text: The assessment of Safety Culture has a great importance among all organizations in nuclear sector. To the extent that, the measurability of safety culture is an issue arises which have to be taken care of. In this study, a method has been proposed to measure safety culture within the organizations, which includes the use of inspection tools to detect the existence of the safety culture characteristics, their related attributes and the fulfillment of provisions of these attributes. Using the safety culture characteristics, attributes and provisions listed in Appendix-1 of IAEA safety standard series ''GS-G- 3.5-The Management System for Nuclear Installations'', a questioner form has been generated for use of regulatory inspectors. The questions in the form are designed to determine whether the provisions of safety culture attributes are fulfilled or not. The inspection method to collect information regarding fulfillment of provisions has been determined according to the nature of scope of provisions. The inspection methods might be one or more of the followings: direct observation, interview with personnel and document review. After filling out the questioner form, an evaluation methodology is performed. According to the answers of questions, the level of fulfillment of provisions has been decided; and according to the level of fulfillment of provisions, the existence of related attributes has been decided. The number of attributes exist are counted and according to resulting number, a grade has been assigned as excellent, good, fair or poor safety culture. Although this questioner form is mainly developed for regulatory inspections of operating organizations; it can also be used, with small modifications, for regulatory body itself (for self-assessment purposes) and for other parties. (author)

[en] The civil nuclear power industry changed forever on 11 March 2011. As the people of Japan came to terms with the devastating effects of a large undersea earthquake and a destructive tsunami, the world watched the evolution of a nuclear accident at the Fukushima-Daiichi Nuclear Power Plant. The effects of that accident are still evident, over four years later, well beyond the areas immediately affected. Public and investor confidence has been eroded. Several existing and proposed nuclear power programmes were stopped or curtailed. However the industry has set out on a rigorous path to ensure the lessons from the event are learned and defences strengthened to make operational safety more robust. The IAEA and its member states unanimously agreed to a Nuclear Safety Action Plan with a comprehensive set of improvements across a wide range of activities. Regulators, utilities and designers of nuclear plants came together to demand, find and implement improvements to nuclear plants and their safe management. And now, in 2015 more than 70 new nuclear units are under construction and several countries have announced their intention to embark on new or expanded nuclear power programmes. This diverse situation poses a number of operational safety challenges to governments, regulators and operators involved in the nuclear industry. It was in this context that the IAEA’s 2015 international conference on operational safety was conceived. The purpose of the conference was to review the progress of operational safety improvements being introduced in the light of the Fukushima Daiichi accident and to foster the exchange of information on operational safety performance and operating experience at nuclear power plants.

[en] Full text: Development of guidelines for severe accident management (SAMG) for Ukrainian NPPs are carried out on the basis of: - An updated national action plan on the results of the ''stress tests''; - ''Comprehensive safety improvement programme of Ukrainian NPPs'' (CSIP) approved by the Cabinet of Ministers of Ukraine; - Working programme for the analysis of severe accidents and development of SAMGs, approved by State Inspectorate for Nuclear Regulation of Ukraine, which establishes general principles, the order and sequence analysis of severe accidents, including design, with the ultimate goal of SAMG development and subsequent SAMG verification and validation for pilot units. At present, SAMGs are developed and implemented only for pilot units, such as: — ZNPP-1 (V-320) - 06.16.2014; SUNPP-1 (B-302) - 28.10.2013; — Rivne NPP-1 (B-213) - 09.04.2014. The SAMGs are applicable to the conditions of intact primary circuit and the Containment. During 2014 and 2013 the State Enterprise ''NAEC'' Energoatom'' performed self-assessment of preparation of NPPs in the areas of Severe Accident Management and Emergency Preparedness. The results of the self-assessment were distributed within WANO-MC members According to the results of SAMG self-assessment, the following conclusions can be made: (a) Several issues were assessed as ''Awaiting Implementation'' as a result of the development of the guidelines for the ''pilot'' Ukrainian NPPs with the subsequent distribution to the ''non-pilot''. According to the CSIP’s schedule for Khmelnitsky NPP, the SAMG are planned to be introduced in 2015 on all power units, that explains why, compared to other nuclear power plants, already having SAMGs, the KNPP has the greatest number of grade ''AI - Awaiting Implementation''. (b) Most issues were assessed as ''Satisfactory progress to date'' received at the South Ukraine NPP, as confirmed by the results of the SUNPP peer review in October 2014. In accordance with the NAEC ''Energoatom'' inspections schedule, similar test was performed at the Rivne nuclear power plant in April 2015. (author)

[en] Full text: After the Fukushima accident EDF has launched a post-Fukushima modification program. An important part of this program consists in strengthening of the Emergency Preparedness Response and the associated means. After a short presentation of all these new equipment and human resources, we make a zoom on the Nuclear Rapid Response Force (FARN): staff and equipment off site able to intervene within the first 24 hours following an alert. We also present the Group Intra created in 1988 by AREVA, CEA and EDF, which can intervene permanently with different sorts of robots able to work in severe radiological conditions. (author)