- Unit 1 experienced an automatic shutdown with damaged core and fuel integrity, decreasing reactor pressure vessel temperature, and severe building damage. - Units 2 and 3 remained in service with stable temperatures but damaged cores, slight building damage in Unit 2 and severe damage in Unit 3, and around half of the fuel uncovered. - Unit 4 was in outage with no fuel in the reactor.
The document reports on the status of 6 nuclear power plant units in the aftermath of an earthquake (EQ). Units 1-4 were in service or undergoing outage at the time. They suffered varying levels of damage to components and structures. All units had lost off-site power but have since had mobile generators connected. Fresh water injection is being provided to reactor pressure vessels and spent fuel pools via portable pumps with off-site power. Core cooling is maintained where possible but fuel damage occurred in some reactors.
This document is the September 2011 issue of the IAEA Bulletin published by the International Atomic Energy Agency (IAEA). It focuses on water issues around the world and how nuclear techniques and IAEA programs are helping to address water challenges. The IAEA serves as an intergovernmental forum for scientific cooperation on peaceful nuclear technology. It helps member states pursue development goals by supporting responsible nuclear planning and facilitating technology transfer. The IAEA also verifies that member states comply with non-proliferation commitments through its inspection system.
The document discusses several international legal instruments related to nuclear safety established by the IAEA: 1) Key conventions include the Convention on Nuclear Safety (CNS), Joint Convention on the Safety of Spent Fuel Management, and conventions on early notification of nuclear accidents and assistance in case of accidents. 2) The conventions establish requirements for contracting parties to report on their implementation of safety obligations and are overseen by a peer review process. 3) The document also discusses non-binding Codes of Conduct for radioactive sources and research reactors that provide guidance to harmonize national laws and policies. 4) The IAEA Safety Standards Series establishes fundamental safety principles and requirements covering various fields of nuclear safety.
This document summarizes radiological monitoring and consequences from the Fukushima Nuclear Accident as of June 2, 2011. Key findings include: - Gamma dose rates were highest in Fukushima prefecture at 1.5 microSievert/hour and decreasing levels in surrounding prefectures. - Low levels of radioactive iodine-131 and cesium-137 were detected in a few prefectures over a few days. - Over 800 food samples from 18 prefectures were tested, with less than 7% exceeding Japanese regulation values for radioactive cesium and/or iodine. Restrictions remained on some foods from Fukushima and Ibaraki.
1) Radioactive contamination from the Fukushima Daiichi nuclear accident spread to the marine environment through atmospheric fallout and discharge of contaminated water into the sea. 2) Monitoring shows contamination levels decreasing in sea water near the plant but remaining relatively constant further offshore due to ongoing water discharge. 3) Sediment near discharge areas shows higher radioactivity, indicating particle adsorption and removal from the water column. Traces of radionuclides may disperse across the northern Pacific ocean over the coming years.
1) The reactor at Fukushima Daiichi Nuclear Power Plant is subcritical and stable, with no significant neutron flux or power increase detected. However, boric acid injection is still being considered to ensure subcriticality is maintained. 2) Residual heat removal is not fully achieved, as a long-term closed-loop cooling system has not been established. Actions are ongoing to install primary and secondary closed-loop cooling systems. 3) Containment integrity is also not fully achieved, as pressure and hydrogen levels continue to be monitored for risks of explosions. The condition of the reactor pressure vessel is unknown.
- The spent fuel pool at Fukushima Daiichi Nuclear Power Plant Unit 4 has partially achieved necessary safety functions, but further actions are needed. - TEPCO assumes the spent fuel assemblies are intact based on water sampling, but more assessment is required. Fresh water is being sprayed into the pool to cool it. - The pool temperature on May 9th was reported as 81°C after spraying, though no recent data was available. Continued water spraying and makeup is needed to fully cool the pool.
The document summarizes the status of fundamental safety functions for Unit 2 at the Fukushima Daiichi nuclear power plant on 18 May 2011. It finds that stable cooling and containment integrity had not been achieved, and that radioactive releases were not fully contained. Water levels in the reactor core were low and the containment was likely damaged. Off-site power and backup generators provided electricity but a long-term closed-loop cooling system had not been established. TEPCO's roadmap included pursuing additional countermeasures to cool the reactor, prevent further releases, and monitor radiation levels.
The document provides an assessment of the status of fundamental safety functions for Unit 1 of the Fukushima Daiichi Nuclear Power Plant as of May 18, 2011. It finds that stable cooling is not achieved and long-term closed-loop heat removal capability has not been established. Containment integrity is achieved but the reactor pressure vessel is assumed to be leaking. Radiation monitoring is available but additional releases are anticipated and radioactive releases should be limited and monitored.
This document summarizes the status of Unit 3 reactor at Fukushima Daiichi nuclear power plant on May 11, 2011 according to TEPCO. It finds that while fresh water is being injected, a closed-loop heat removal system has not been established, and the reactor temperature and pressure remain high. The containment vessel is believed to be damaged based on pressure readings, and intermittent radiation releases continue. Analysis of water from the spent fuel pool detected high levels of cesium-134 and -136, indicating damage to stored fuel rods.
The document summarizes the status of Unit 2 at the Fukushima Daiichi nuclear power plant on May 11, 2011 in terms of achieving four fundamental safety functions: control of reactivity, residual heat removal, containment integrity, and limiting effects of releases. It finds that only reactivity control had been achieved, while the other three functions had not been achieved. In particular, residual heat removal had not been established through a long-term closed-loop system, containment was likely damaged and leaking, and intermittent radioactive releases were still being observed.
The document provides an assessment of the status of fundamental safety functions at Fukushima Daiichi Nuclear Power Plant Unit 1 as of May 11, 2011. It finds that reactivity control and containment integrity have been achieved, but residual heat removal and confinement of radioactive material are only partially achieved. Radiation monitoring and limiting effects of releases are also only partially achieved due to intermittent releases observed and assumed leaks from the reactor pressure vessel and containment vessel. TEPCO's roadmap includes countermeasures to establish closed-loop cooling and reduce radiation levels.
This document provides information on 6 nuclear power plant units in the aftermath of an earthquake. Unit 1 experienced damage to its core and fuel integrity and was decreasing in reactor pressure vessel (RPV) temperature. Units 2 and 3 also showed damaged cores and fuel but stable RPV temperatures. Unit 4 was in outage so no fuel was present. Unit 5 was also in outage with no immediate concerns reported. Unit 6 was in cold shutdown with water levels and pressures being maintained using off-site power and equipment.
The document summarizes monitoring data from the marine environment near Fukushima, Japan following the nuclear accident. Contaminated water was discharged into the sea through the facility and through atmospheric deposition. Sampling shows decreasing levels of radioactive isotopes like I-131 and Cs-137 farther offshore but some contamination of fish. Modeling predicts the plume will disperse into the northern Pacific ocean over the next few years. Atmospheric monitoring in Monaco detected some radioactive isotopes but at much lower levels than following Chernobyl. Ongoing sampling will continue to assess the marine environment and track the plume's movement.
The document summarizes radiological monitoring and consequences from the Fukushima Nuclear Accident. Gamma dose rates were measured in 47 prefectures from March 24th to May 4th, with Fukushima prefecture recording a rate of 1.7 μSv/h. I-131 and Cs-137 were detected in drinking water samples from 2-6 prefectures respectively at levels below restriction levels. Internal and external radiation doses received by emergency workers through the end of March 2011 included 2 workers receiving 200-250 mSv and 8 receiving 150-200 mSv.
The document provides a technical briefing on the status of reactor units 1-3 at the Fukushima Daiichi nuclear power plant as of May 5th, 2011. It assesses the current status of each unit and efforts to achieve a safe shutdown state after the earthquake and tsunami in March 2011. It also includes videos of the spent fuel pool at unit 4 from May 5th, 2011.
This technical briefing from Miroslav Lipar on April 19th, 2011 summarizes reactor unit status and the total deposition and layer concentration of Iodine-131 and Cesium-137 according to regional and global models from March 14th to April 13th, 2011. The briefing includes data on Iodine-131 and Cesium-137 deposition and concentration from regional models analyzing specific areas as well as global models looking at broader trends.
The document summarizes monitoring of radioactive contamination in the marine environment near Fukushima, Japan following the nuclear accident. It notes that contamination has occurred through atmospheric fallout and discharge of contaminated water. Sample results show decreasing levels of iodine-131 and cesium-137 over time, with the highest levels near shore. Japanese authorities are continuing sampling of seawater, biota, and performing an environmental impact assessment under direction of NISA. The IAEA is collaborating and ready to assist Japan if requested.
This document summarizes radiological monitoring and consequences from the Fukushima Nuclear Accident in Japan between March 19th and April 18th, 2011. Gamma dose rates were highest in Fukushima prefecture at 1.9 microsieverts per hour, above natural background levels. Daily deposition of radioactive iodine-131 and cesium-137 were monitored. Foodstuff samples from 8 prefectures did not detect radioactive materials above regulation values. Drinking water in all prefectures was far below restriction levels for iodine-131 and cesium-137, though one village in Fukushima had precautions for infants due to detected iodine-131.
The document reports on the status of 6 nuclear power plant units in the aftermath of an earthquake. Unit 1 experienced damaged core and fuel integrity with a high but stable reactor pressure vessel temperature. Fresh water was being injected into the reactor pressure vessel and spent fuel pool via mobile pumps. Unit 2 had severe core damage and an increasing reactor pressure vessel temperature but fresh water injection was restoring cooling. Units 3 and 4 had damaged cores but stable reactor conditions and were receiving fresh water injection to cooling systems. Units 5 and 6 were in cold shutdown during maintenance and remained stable using off-site power.
The IAEA's Technical Cooperation Programme aims to maximize the contribution of nuclear technology to the world while verifying its peaceful use. It has six departments and works through partnerships with UN organizations in areas like human health, food and agriculture, water and the environment, and nuclear energy and safety. The programme operates in over 125 countries and focuses on achieving the Millennium Development Goals by 2015 through projects like improving disease treatment, increasing crop and livestock production, and supporting sustainable water and environmental resources.
The IAEA's Technical Cooperation Programme works to promote peaceful uses of nuclear technology through projects in member states. It was established in 1957 to accelerate contributions of atomic energy to peace, health and prosperity worldwide. The programme supports projects in areas like agriculture, health, water resources and more. In 2010, it disbursed over $114 million to projects in 129 countries and territories.
The document summarizes seawater sampling data from off the coast of Fukushima, Japan following the Fukushima Daiichi nuclear disaster. Sampling was conducted by Japanese authorities MEXT and TEPCO at various distances from the coastline. The highest levels of radioactive iodine-131 and cesium-137 were found close to shore, with concentrations decreasing further offshore and over time. If no additional radioactive releases occur, concentrations measured 30 km offshore are expected to continue decreasing significantly through dilution and dispersion by ocean currents. An expert from the IAEA visited Japan to review marine sampling and measurements.
The document summarizes the status of fundamental safety functions for Unit 2 at the Fukushima Daiichi nuclear power plant on 18 May 2011. It finds that stable cooling and containment integrity had not been achieved, and that radioactive releases were not fully contained. Water levels in the reactor core were low and the containment was likely damaged. Off-site power and backup generators provided electricity but a long-term closed-loop cooling system had not been established. TEPCO's roadmap included pursuing additional countermeasures to cool the reactor, prevent further releases, and monitor radiation levels.
The document provides an assessment of the status of fundamental safety functions for Unit 1 of the Fukushima Daiichi Nuclear Power Plant as of May 18, 2011. It finds that stable cooling is not achieved and long-term closed-loop heat removal capability has not been established. Containment integrity is achieved but the reactor pressure vessel is assumed to be leaking. Radiation monitoring is available but additional releases are anticipated and radioactive releases should be limited and monitored.
This document summarizes the status of Unit 3 reactor at Fukushima Daiichi nuclear power plant on May 11, 2011 according to TEPCO. It finds that while fresh water is being injected, a closed-loop heat removal system has not been established, and the reactor temperature and pressure remain high. The containment vessel is believed to be damaged based on pressure readings, and intermittent radiation releases continue. Analysis of water from the spent fuel pool detected high levels of cesium-134 and -136, indicating damage to stored fuel rods.
The document summarizes the status of Unit 2 at the Fukushima Daiichi nuclear power plant on May 11, 2011 in terms of achieving four fundamental safety functions: control of reactivity, residual heat removal, containment integrity, and limiting effects of releases. It finds that only reactivity control had been achieved, while the other three functions had not been achieved. In particular, residual heat removal had not been established through a long-term closed-loop system, containment was likely damaged and leaking, and intermittent radioactive releases were still being observed.
The document provides an assessment of the status of fundamental safety functions at Fukushima Daiichi Nuclear Power Plant Unit 1 as of May 11, 2011. It finds that reactivity control and containment integrity have been achieved, but residual heat removal and confinement of radioactive material are only partially achieved. Radiation monitoring and limiting effects of releases are also only partially achieved due to intermittent releases observed and assumed leaks from the reactor pressure vessel and containment vessel. TEPCO's roadmap includes countermeasures to establish closed-loop cooling and reduce radiation levels.
This document provides information on 6 nuclear power plant units in the aftermath of an earthquake. Unit 1 experienced damage to its core and fuel integrity and was decreasing in reactor pressure vessel (RPV) temperature. Units 2 and 3 also showed damaged cores and fuel but stable RPV temperatures. Unit 4 was in outage so no fuel was present. Unit 5 was also in outage with no immediate concerns reported. Unit 6 was in cold shutdown with water levels and pressures being maintained using off-site power and equipment.
The document summarizes monitoring data from the marine environment near Fukushima, Japan following the nuclear accident. Contaminated water was discharged into the sea through the facility and through atmospheric deposition. Sampling shows decreasing levels of radioactive isotopes like I-131 and Cs-137 farther offshore but some contamination of fish. Modeling predicts the plume will disperse into the northern Pacific ocean over the next few years. Atmospheric monitoring in Monaco detected some radioactive isotopes but at much lower levels than following Chernobyl. Ongoing sampling will continue to assess the marine environment and track the plume's movement.
The document summarizes radiological monitoring and consequences from the Fukushima Nuclear Accident. Gamma dose rates were measured in 47 prefectures from March 24th to May 4th, with Fukushima prefecture recording a rate of 1.7 μSv/h. I-131 and Cs-137 were detected in drinking water samples from 2-6 prefectures respectively at levels below restriction levels. Internal and external radiation doses received by emergency workers through the end of March 2011 included 2 workers receiving 200-250 mSv and 8 receiving 150-200 mSv.
The document provides a technical briefing on the status of reactor units 1-3 at the Fukushima Daiichi nuclear power plant as of May 5th, 2011. It assesses the current status of each unit and efforts to achieve a safe shutdown state after the earthquake and tsunami in March 2011. It also includes videos of the spent fuel pool at unit 4 from May 5th, 2011.
This technical briefing from Miroslav Lipar on April 19th, 2011 summarizes reactor unit status and the total deposition and layer concentration of Iodine-131 and Cesium-137 according to regional and global models from March 14th to April 13th, 2011. The briefing includes data on Iodine-131 and Cesium-137 deposition and concentration from regional models analyzing specific areas as well as global models looking at broader trends.
The document summarizes monitoring of radioactive contamination in the marine environment near Fukushima, Japan following the nuclear accident. It notes that contamination has occurred through atmospheric fallout and discharge of contaminated water. Sample results show decreasing levels of iodine-131 and cesium-137 over time, with the highest levels near shore. Japanese authorities are continuing sampling of seawater, biota, and performing an environmental impact assessment under direction of NISA. The IAEA is collaborating and ready to assist Japan if requested.
This document summarizes radiological monitoring and consequences from the Fukushima Nuclear Accident in Japan between March 19th and April 18th, 2011. Gamma dose rates were highest in Fukushima prefecture at 1.9 microsieverts per hour, above natural background levels. Daily deposition of radioactive iodine-131 and cesium-137 were monitored. Foodstuff samples from 8 prefectures did not detect radioactive materials above regulation values. Drinking water in all prefectures was far below restriction levels for iodine-131 and cesium-137, though one village in Fukushima had precautions for infants due to detected iodine-131.
The document reports on the status of 6 nuclear power plant units in the aftermath of an earthquake. Unit 1 experienced damaged core and fuel integrity with a high but stable reactor pressure vessel temperature. Fresh water was being injected into the reactor pressure vessel and spent fuel pool via mobile pumps. Unit 2 had severe core damage and an increasing reactor pressure vessel temperature but fresh water injection was restoring cooling. Units 3 and 4 had damaged cores but stable reactor conditions and were receiving fresh water injection to cooling systems. Units 5 and 6 were in cold shutdown during maintenance and remained stable using off-site power.
The IAEA's Technical Cooperation Programme aims to maximize the contribution of nuclear technology to the world while verifying its peaceful use. It has six departments and works through partnerships with UN organizations in areas like human health, food and agriculture, water and the environment, and nuclear energy and safety. The programme operates in over 125 countries and focuses on achieving the Millennium Development Goals by 2015 through projects like improving disease treatment, increasing crop and livestock production, and supporting sustainable water and environmental resources.
The IAEA's Technical Cooperation Programme works to promote peaceful uses of nuclear technology through projects in member states. It was established in 1957 to accelerate contributions of atomic energy to peace, health and prosperity worldwide. The programme supports projects in areas like agriculture, health, water resources and more. In 2010, it disbursed over $114 million to projects in 129 countries and territories.
The document summarizes seawater sampling data from off the coast of Fukushima, Japan following the Fukushima Daiichi nuclear disaster. Sampling was conducted by Japanese authorities MEXT and TEPCO at various distances from the coastline. The highest levels of radioactive iodine-131 and cesium-137 were found close to shore, with concentrations decreasing further offshore and over time. If no additional radioactive releases occur, concentrations measured 30 km offshore are expected to continue decreasing significantly through dilution and dispersion by ocean currents. An expert from the IAEA visited Japan to review marine sampling and measurements.
Summary of Reactor Unit Status (8 April 2011, 07:00 UTC)
1. 04/08/2011 07:00 UTC Unit 1 2 3 4 Power (MWe /MWth) 460/1380 784/2381 784/2381 784/2381 Type of Reactor BWR-3 BWR-4 BWR-4 BWR-4 Status at time of EQ In service – auto shutdown In service – auto shutdown In service – auto shutdown Outage Core and fuel integrity Damaged Severe damage Damaged No fuel in the Reactor RPV & RCS integrity RPV temperature high but stable RPV temperature stable RPV temperature stable Not applicable due to outage plant status Containment integrity No information Damage suspected Damage suspected AC Power AC power available - power to instrumentation – Lighting to Central Control Room AC power available – power to instrumentation – Lighting to Central Control Room AC power available – power to instrumentation – Lighting to Central Control Room AC power available – power to instrumentation – Lighting to Central Control Room Building Severe damage Slight damage Severe damage Severe damage Water level of RPV Around half of Fuel is uncovered Around half of Fuel is uncovered Around half of Fuel is uncovered Not applicable due to outage plant status Pressure of RPV Increasing Stable Stable CV Pressure Drywell Increasing Stable Stable Water injection to RPV Injection of freshwater – via mobile electric pump with off-site power Injection of freshwater – via mobile electric pump with off-site power Injection of freshwater – via mobile electric pump with off-site power Water injection to CV No information No information No information Spent Fuel Pool Status Fresh water spraying completed by concrete pump truck Freshwater injection to the Fuel Pool Cooling Line Freshwater injection via Fuel Pool Cooling Line and Periodic spraying Fresh water spraying completed by concrete pump truck
2. 04/08/2011 07:00 UTC Unit 5 6 Power 784/2381 1100/3293 Type of Reactor BWR-4 BWR-5 Status at the EQ occurred Outage Outage Core and Fuel Cold Shutdown Being maintained using off-site electrical power and existing plant equipment. Cold Shutdown Being maintained using off-site electrical power and existing plant equipment. RPV & RCS integrity Containment int. AC Power Building Water level of RPV Pressure of RPV Containment Pressure Water injection to RPV Water injection to CV Spent Fuel Pool Status Severe condition Concern No immediate concern