201,847 research outputs found
Coordination Under Uncertain Conditions: An Analysis of the Fukushima Catastrophe
No full textThis paper analyzes the impacts of the 11 March 2011 earthquake and tsunami at the Fukushima nuclear power plant in Japan, which were amplified by a failure of coordination across the plant, corporate, industrial, and regulatory levels, resulting in a nuclear catastrophe, comparable in cost to Chernobyl. It derives generic lessons for industrial structure and regulatory frame of the electric power industry by identifying the two shortcomings of a horizontal coordination mechanism: instability under large shock and the lack of “defense in depth.”fukushima catastrophe; nuclear power; earthquake and tsunami
Organizations under Large Uncertainty: An Analysis of the Fukushima Catastrophe
No full textThis paper analyzes the impacts of the March 11, 2011, earthquake and tsunami at the Fukushima nuclear power plant in Japan, which were amplified by a failure of coordination across the plant, corporate, industrial, and regulatory levels, resulting in a nuclear catastrophe comparable in cost to Chernobyl. It derives generic lessons for industrial structure and regulatory frame for the electric power industry by identifying the two shortcomings of a horizontal coordination mechanism: instability under large shocks and the lack of defense in depth.The suggested policy response is to harness the power of Òopen-interface-rule-based modularity by creating an independent nuclear safety commission and an independent system operator owning the transmission grid module in Japan. We propose a transitory price mechanism that can restrain price volatility while providing investment incentives.horizontal coordination, modularity, nuclear power, regional monopoly, electricity regulation, safety regulation, public ownership, independent system operator
German energy market fallout from the Japanese earthquake
No full textThe German response to the Fukushima nuclear power plant incident was possibly the most significant change of policy towards nuclear power outside Japan, leading to a sudden and very significant shift in the underlying power generation structure in Germany. This provides a very useful natural experiment on the impact of changing proportions of conventional fuel inputs to power production, helping us to see how changed proportions in future as a result of policy moves are likely to impact. We find through use of a conventional demand- supply framework that despite the swift, significant change, the main impact was a relatively modest increase in prices occasioned by a shift of the supply curve; there were no appreciable quantity effects on the market, such as power outages, despite some views that the impacts would be significant
Design Safety Considerations for Water Cooled Small Modular Reactors Incorporating Lessons Learned from the Fukushima Daiichi Accident
No full textThe global future deployment of advanced nuclear reactors for electricity generation depends
primarily on the ability of nuclear industries, utilities and regulatory authorities to further
enhance their reliability and economic competitiveness while satisfying stringent safety requirements. The IAEA has a project to help coordinate Member State efforts in the development and deployment of small and medium sized or small modular reactor (SMR) technology. This project aims simultaneously to facilitate SMR technology developers and potential SMR users, particularly States embarking on a nuclear power programme, in identifying key enabling technologies and enhancing capacity building by resolving issues relevant to deployment, including nuclear reactor safety.
The objective of this publication is to explore common practices for Member States, which will be an essential resource for future development and deployment of SMR technology. The accident at the Fukushima Daiichi nuclear power plant was caused by an unprecedented combination of natural events: a strong earthquake, beyond th
e design basis, followed by a series of tsunamis of heights exceeding the design basis tsunami considered in the flood analysis for the site. Consequently, all the operating nuclear power plants and advanced reactors under development, including SMRs, have been incorporating lessons learned from the accident to assure and enhance the performance of the engineered safety features in coping with such external events.
In response to the Fukushima Daiichi accident, the IAEA established an Action Plan on Nuclear Safety. The preparation of this publication was carried out within the framework of the IAEA Action Plan on effectively utilizing
research and development. The main objective of this publication is to present technology developers and user
s with common considerations, approaches and measures for enhancing the defence in depth and operability of water cooled SMR design concepts to cope with extreme natural hazards. Indicative requirements to prevent such an accident from recurring are also provided for States planning to adopt water cooled SMR designs and technologies.
The IAEA gratefully acknowledges the information on technology and safety aspects provided by SMR design organizations and information regarding technical requirements provided by several Member States. The IAEA officers responsible for this publication were M.H. Subki of the Division of Nuclear Power and M. Kim of the Division of Nuclear Installation Safety
Report on the 23rd Fukushima Dialogue “Thinking together about issues of Fukushima Daiichi treated water”
No full textOn 27 November 2021, the non-profit organization (NPO) Fukushima Dialogue held the 23rd Fukushima Dialogue meeting in Naraha Machi, Fukushima Prefecture. The theme was “Sharing the situation surrounding Fukushima Daiichi treated water”. It was the 23rd meeting since the International Commission on Radiological Protection (ICRP) launched the ICRP Dialogue in Fukushima Prefecture in 2011, which the NPO Fukushima Dialogue took over in 2019. Held in a hybrid form, it was open to the public and has gathered up to 120 participants. The first part was devoted to presentations related to the theme of the meeting: technical aspects, testimonies about local (institutional or not) and foreign (Korea) perception, experiences from abroad of stakeholder involvement in the nuclear field. The second part was devoted to a structured dialogue between a panel of local citizens. The audience was participatory. This article summarizes the fruitful exchanges during these two days
Analysis of accident progression of Fukushima Dai-ichi with SAMPSON Code - (3) UNIT 3
No full textOn March 11th 2011 at 14:46 an extremely high magnitude earthquake struck the East coast of Japan. One minute later, at Fukushima Daiichi, all reactors started scram as design operation. Later on, due to the struck of tsunami AC power, provided by diesel generators, stopped and Residual Heat Removal (RHR) system failed to be activated in all the operating units. The follow-up of the transients highly depended on the plants' availability of DC power and on valve operability. DC power given by batteries provides energy for valve operation of those safety systems which do not directly necessitate AC power, that is to say: Isolation Condenser (Unit 1), RCIC and HPCI (Unit 2 and 3). At Unit 3 measurements of the two main parameters from Tokyo Electric Power Company (TEPCO) are available until the hydrogen explosion which occurred on March 14th. However, measurement data are often incoherent between activation of SR Vs, water level and core pressure, frequently missing and likely to become more and more imprecise following the accident progression due to measurement tools degradation. Severe accident codes such as SAMPSON are therefore crucial tools to provide information about the accident, in order to fill the incompleteness of the available measurements, give prediction of the current plant conditions and enhance understanding of the events. The analysis of Unit 3 is here presented through the severe accident code SAMPSON until termination of HPCI. At this time the core is predicted to be always abundantly covered by water and providing high confidence about the availability of emergency systems like RCIC and HPCI for Unit 3. The present analysis represents an effort to reconstruct the accident progression and show the ability and improvements of the modules employed in SAMPSON for severe accident analysis
Fine scale eddies in turbulent Taylor-Couette flow up to Re 25 000
No full textReynolds number effects on fine scale eddies in the turbulent Taylor-Couette flow have been investigated by high accuracy direct numerical simulations from Re = 8000 to 25 000. The Reynolds number dependency of the mean torque changes near Re = 10 000, and the transition is closely linked to the turbulence characteristics. As the Reynolds number increases, the fine scale eddies are more densely populated and take more various tilting angles. The joint probability density function of the tilting angle and the radial position exhibits a preferential pattern corresponding to the large scale motion of Taylor vortices. The present results suggest that in this Reynolds number range, the fine scale eddies progressively prevail a large part of the domain, and their contribution to the fundamental statistics such as the Reynolds shear stress becomes more evident
Hydrodynamic Model of Fukushima-Daiichi Site Flooding
No full textПри проектировании и строительстве АЭС Fukushima-Daiichi максимальная
высота цунами на основе анализа статистических данных (с учетом
землетрясения в Чили в 1960 г.) оценивалась приблизительно в 3 м. Проектная
высота площадки АЭС составила 10 м. Дальнейшие детерминистические оценки
TEPCO — JSCE подтвердили невозможность затопления промплощадки
Fukushima-Daiichi цунами. Однако в результате запроектного землетрясения
11.03.2011 высота цунами у побережья АЭС Fukushima-Daiichi достигла 15 м, что
привело к затоплению и возникновению тяжелых аварий.
В данной работе предложена гидродинамическая модель возникновения
и распространения цунами на основе консервативных допущений. В результате
численного моделирования установлена возможность достижения высоты волны
15 м у побережья АЭС Fukushima-Daiichi при значении приведенного
коэффициента гидродинамического сопротивления 1,8. Согласно разработанной
модели возможность затопления определяется не только высотой промплощадки,
мощностью и расстоянием землетрясения, но и продолжительностью
сейсмических толчков, условиями диссипации энергии, размерами эпицентра
и другими факторами.У процесі проектування й будівництва АЕС Fukushima-Daiichi максимальна висота
цунамі на основі аналізу статистичних даних (з урахуванням землетрусу в Чилі
у 1960 р.) оцінювалася приблизно в 3 м. Проектна висота майданчика АЕС
становила 10 м. Подальші детерміністичні оцінки TEPCO — JSCE підтвердили
неможливість затоплення проммайданчика Fukushima-Daiichi цунамі. Проте
внаслідок позапроектного землетрусу 11.03.2011 висота цунамі у побережжя АЕС
Fukushima-Daiichi досягла 15 м, що призвело до затоплення й виникнення важких
аварій.
У даній роботі запропоновано гідродинамічну модель виникнення
й розповсюдження цунамі на основі консервативних допущень. У результаті
чисельного моделювання встановлено можливість досягнення висоти хвилі 15 м
у побережжя АЕС Fukushima-Daiichi при значенні приведеного коефіцієнта
гідродинамічного опору 1,8. Згідно з розробленою моделлю можливість затоплення
визначається не тільки висотою проммайданчика, потужністю і відстанню
землетрусу, але й тривалістю сейсмічних поштовхів, умовами дисипації енергії,
розмірами епіцентра та іншими чинниками.Based on analysis of statistics (including the Chile earthquake in 1960), the maximum
height of a tsunami was evaluated at about 3 m in the design and construction of
Fukushima-Daiichi. The design level of the NPP site was 10 m. Further TEPCO–JSCE
deterministic evaluations confirmed that the Fukushima-Daiichi site could hardly be
flooded in a tsunami. However, the beyond design basis earthquake on 11 March 2011
caused a tsunami that reached 15 m on the Fukushima-Daiichi coastline and led to
flooding and severe accidents.
Based on conservative assumptions, this paper proposes a hydrodynamic model to
describe the occurrence and spread of a tsunami. Numerical simulation has shown that a
wave can reach 15 m on the Fukushima-Daiichi coastline with the reduced
hydrodynamic resistance factor being 1.8. According to the developed model, the
likelihood of flooding is determined not only by the site level, earthquake intensity and
distance, but also by the duration of seismic impacts, conditions of energy dissipation,
epicenter size and other factors
MESA-REDONDA MASANORI FUKUSHIMA
No full textMesa-redonda Masanori Fukushima. Participantes: Ana González; Cristina Mendes; Fernando Bini; Geraldo Leão. Mediação: Tânia Bloomfield. Departamento de Comunicação Social, UFPR, em 26/05/2023. Vídeo: 82 m
Hydrodynamic Model of Fukushima-Daiichi Site Flooding
No full textПри проектировании и строительстве АЭС Fukushima-Daiichi максимальная
высота цунами на основе анализа статистических данных (с учетом
землетрясения в Чили в 1960 г.) оценивалась приблизительно в 3 м. Проектная
высота площадки АЭС составила 10 м. Дальнейшие детерминистические оценки
TEPCO — JSCE подтвердили невозможность затопления промплощадки
Fukushima-Daiichi цунами. Однако в результате запроектного землетрясения
11.03.2011 высота цунами у побережья АЭС Fukushima-Daiichi достигла 15 м, что
привело к затоплению и возникновению тяжелых аварий.
В данной работе предложена гидродинамическая модель возникновения
и распространения цунами на основе консервативных допущений. В результате
численного моделирования установлена возможность достижения высоты волны
15 м у побережья АЭС Fukushima-Daiichi при значении приведенного
коэффициента гидродинамического сопротивления 1,8. Согласно разработанной
модели возможность затопления определяется не только высотой промплощадки,
мощностью и расстоянием землетрясения, но и продолжительностью
сейсмических толчков, условиями диссипации энергии, размерами эпицентра
и другими факторами.У процесі проектування й будівництва АЕС Fukushima-Daiichi максимальна висота
цунамі на основі аналізу статистичних даних (з урахуванням землетрусу в Чилі
у 1960 р.) оцінювалася приблизно в 3 м. Проектна висота майданчика АЕС
становила 10 м. Подальші детерміністичні оцінки TEPCO — JSCE підтвердили
неможливість затоплення проммайданчика Fukushima-Daiichi цунамі. Проте
внаслідок позапроектного землетрусу 11.03.2011 висота цунамі у побережжя АЕС
Fukushima-Daiichi досягла 15 м, що призвело до затоплення й виникнення важких
аварій.
У даній роботі запропоновано гідродинамічну модель виникнення
й розповсюдження цунамі на основі консервативних допущень. У результаті
чисельного моделювання встановлено можливість досягнення висоти хвилі 15 м
у побережжя АЕС Fukushima-Daiichi при значенні приведеного коефіцієнта
гідродинамічного опору 1,8. Згідно з розробленою моделлю можливість затоплення
визначається не тільки висотою проммайданчика, потужністю і відстанню
землетрусу, але й тривалістю сейсмічних поштовхів, умовами дисипації енергії,
розмірами епіцентра та іншими чинниками.Based on analysis of statistics (including the Chile earthquake in 1960), the maximum
height of a tsunami was evaluated at about 3 m in the design and construction of
Fukushima-Daiichi. The design level of the NPP site was 10 m. Further TEPCO–JSCE
deterministic evaluations confirmed that the Fukushima-Daiichi site could hardly be
flooded in a tsunami. However, the beyond design basis earthquake on 11 March 2011
caused a tsunami that reached 15 m on the Fukushima-Daiichi coastline and led to
flooding and severe accidents.
Based on conservative assumptions, this paper proposes a hydrodynamic model to
describe the occurrence and spread of a tsunami. Numerical simulation has shown that a
wave can reach 15 m on the Fukushima-Daiichi coastline with the reduced
hydrodynamic resistance factor being 1.8. According to the developed model, the
likelihood of flooding is determined not only by the site level, earthquake intensity and
distance, but also by the duration of seismic impacts, conditions of energy dissipation,
epicenter size and other factors
- …
