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Technical Briefing on Radiological Situation in Japan - 21 March 2011

International Atomic Energy Agency
International Atomic Energy Agency

The document summarizes the current radiological situation at the Fukushima Daiichi nuclear power plant based on measurements taken by the IAEA monitoring team on March 20th and 21st. It reports gamma dose rates ranging from 2-160 microsieverts per hour and beta-gamma contamination levels ranging from 0.2-0.9 MBq per square meter at locations between 16-58 km from the plant. Very high contamination levels were measured within 20 km of the plant. The IAEA will continue monitoring efforts and is seeking additional data from Japan on radioactivity measurements across the country.

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Opening Remarks Technical Briefing (21/3/2011) 1. Current Situation We are seeing some steady improvements, but the overall situation at the Fukushima Daiichi nuclear power plant remains very serious. High levels of contamination have been measured in the locality of the plant. The restoration of electrical power to Unit 2, which we reported yesterday, is good news. AC power is available and an electrical load check to pumps etc. is currently on-going. Work on the restoration of off-site power to Units 3 and 4 is also underway. Seawater is still being injected into the reactor pressure vessels of Units 1, 2 and 3. Pressure in the reactor pressure vessel and the containment vessel drywell at Unit 3, which had been rising yesterday, has again fallen. Water is being sprayed periodically into the spent fuel pools at Units 2, 3 and 4. The Agency still lacks data on water levels and temperatures in the spent fuel pools at Units 1, 2, 3 and 4. Following the restoration of cooling at Units 5 and 6, temperatures in the spent fuel pools continue to decline. 2. Radiation Monitoring As I reported yesterday, the IAEA radiation monitoring team took measurements at distances from 56 to 200 km from the Fukushima nuclear power plant. At two locations in Fukushima Prefecture gamma dose rate and beta-gamma contamination measurements have been repeated. These measurements showed high beta-gamma contamination levels. Measurements by the IAEA and the Japanese authorities were taken at the same time and locations. The Japanese and independent IAEA measurements gave comparable results. Measurement of gamma dose rate and beta-gamma contamination were taken on 20 March at more locations. The dose-rate results ranged from 2-160 microsieverts per hour, which compares to a typical natural background level of around 0.1 microsieverts per hour. High- levels of beta-gamma contamination have been measured between 16-58 km from the plant. Available results show contamination ranging from 0.2-0.9 MBq per square metre. Further measurements are needed to assess possible contamination beyond the area currently monitored both closer to the facility and further way. We have no contamination measurements showing that that contamination levels are high at greater distances than 58 km from the plant, but this cannot be excluded. I have no further information available regarding the measurement of alpha radiation. As I reported yesterday, from the measurements taken within the evacuation zone (20 km), no significant alpha radiation had been detected at that time. In the coming days, the IAEA monitoring team will continue to take measurements in the Fukushima prefecture. We are seeking data from Japan on radioactivity contamination measurements for the rest of Japan.
Some results on the monitoring of foodstuffs have been made available by Japan to the IAEA and FAO. Results provided recently by the Japanese authorities range up to 55,000 Bq per kg of I-131 in samples of Spinach taken in in the Ibaraki Prefecture. These high values are significantly above Japanese limits for restricting food consumption (i.e. 2,000 Bq/kg). I understand that the Japanese Government is actively considering relevant precautionary measures and has instructed four Prefectures (Ibaraki, Totigi, Gunma, Fukushima) to refrain, for the time being, from distributing two types of vegetables (spinach and kakina) from these Prefectures and milk from Fukshima. 3. Agency Activities The Director General briefed the Board of Governors today on the outcome of his visit to Tokyo.
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 In service auto In service auto In service auto Status at time of EQ Outage shutdown shutdown shutdown Core and fuel integrity Damaged Damaged Damaged No fuel in the Reactor RPV & RCS integrity Unknown Unknown Unknown Not applicable due to Containment integrity Not Damaged Damage suspected No information outage plant status AC Power available AC Power Substation connected Not available Not available Load check is ongoing Building Severe damage Slight damage Severe damage Severe damage Around half of Fuel is Around half of Fuel is Around half of Fuel is Water level of RPV uncovered (Stable) uncovered (Stable) uncovered (Stable) Pressure of RPV Stabilized Unreliable Readings Decreased Not applicable due to CV Pressure Drywell Stable Stable Decreased outage plant status Water injection to RPV Seawater Seawater Seawater Water injection to CV No information No information No information Periodic spraying from Periodic spraying from Periodic spraying Spent Fuel Pool Status No information outside outside from outside 3/21/2011 07:00 AM
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 Cold Shutdown Severe condition RPV & RCS integrity Intact Intact Containment int. No damage expected No damage expected Concern AC Power 2nd Emergency diesel from Emergency diesel Unit 6 Off-site power being restored No immediate concern Building No damage reported No damage reported Water level of RPV Above fuel Above fuel Pressure of RPV Cooling restored Cooling restored Containment Pressure No information No information Water injection to RPV Injection in Progress Injection in Progress Water injection to CV Not needed now Not needed now Spent Fuel Pool Status Cooling restored Cooling restored 3/21/2011 07:00 AM
Technical Briefing on the Radiological Situation in Japan 21 March 2011 IAEA International Atomic Energy Agency
Daiichi NPP On-Site gamma dose rate (updated) IAEA
Evolution of gamma dose rates after radioactive releases surrounding Daiichi NPP since 15 March 2011 (Selected monitoring posts) IAEA Information provided by MEXT-Japan
Gamma dose rates North of Daiichi NPP Japan (microSv/h), 15-20 March IAEA
Gamma dose rates between Tokyo and Daiichi NPP (microSv/h), 15-20 March IAEA
Gamma dose rates close to Tokyo, (microSv/h), 15-20 March IAEA
Measurements by the IAEA monitoring team on 20 March 2011 Location Distanc Time,JST Doserate Alpha beta+ Contamination eto (24h) micro (counts gamma Becquerelper Mega NPP Sv/h per (countsper cm 2 Becquerel (km) second) second) perm2 MiniStopnear Kawamata Hospital 58 10:32 5.7 0 3440 58.5 0.585 NihonmatsuTowa cho 52 10:55 4.2 0 2368 40.3 0.403 Towacho Michino eki 49 11:05 3.1 0 1270 21.6 0.216 AtcrossingofRoad 349andRoad50 46 11:30 1.9 0 1973 33.5 0.335 Suichuji busstop 43 11:42 2 0 2260 38.4 0.384 JATamura 39 11:57 2.6 0 2265 38.5 0.385 Borderbetween Kuzuomura and 34 12:09 11.7 0 3152 53.6 0.536 Tamurashi Kuzuo villageoffice 29 13:47 11.2 0 4874 82.9 0.829 Road50 28 15:25 7.2 0 5030 85.5 0.855 Borderbetween Namie townand 20 14:55 161 0 overload na na Kuzuo village GateofOgakidam managementoffice 16 14:31 83 0 overload na na IAEA 7
Measurements by the IAEA monitoring team on 19 March 2011 Location Time, Distance Dose Alpha beta+ Contamination JST from rate (counts gamma (24h) Fukushim (micro per (countsper a Sv/h) second) second) Becquerel Mega Daiichi percm2 Becquerel NPP(km) perm2 Saitama Prefecture Hasuda 17:00 200 0.04 0 27 - Tochigi Prefecture Sano 17:27 180 0.16 0 150 2.5 0.03 Kamikochi 18:17 140 0.18 0.2*) 240 4.1 0.04 Nasukogem 20:17 220 2.9 0 2300 39.3 0.39 Fukushimi Prefecture Abukuma 21:05 60 3.5 0.08*) 3750 64 0.64 Gohyakugawa 21:58 56 3 0 3900 66.3 0.66 IAEA 8
Maps with prefectures where foodstuffs were measured IAEA 9
Ibaraki: Results from measurements of radionuclides in foodstuffs Name SamplingDate Spniach&otherleafyvegs SpringOnion Milk(unprocessed) UNITS JST I131 Cs137 I131 Cs137 I131 Cs137 Cs134 Kitaibaraki 18Mar 24000 690 350 ND (Bq/kg) Kamisu 17Mar 56 ND (Bq/kg) Yachiyo 17Mar 78 21 (Bq/kg) Takahagi 19Mar 11,000 586 (Bq/kg) Hokota 19Mar 1900 71 (Bq/kg) Hokota 19Mar 480 81 (Bq/kg) Hitachi City 18Mar 54100 1931 (Bq/kg) Hitachi City 18Mar 25200 1105 (Bq/kg) Hitachi Omiya 18Mar 19200 1040 (Bq/kg) Hitachi Omiya 18Mar 17800 908 (Bq/kg) Naka 18Mar 16100 911 (Bq/kg) Naka 18Mar 13500 966 (Bq/kg) Hokota 18Mar 7710 407 356 9 (Bq/kg) Moriya 18Mar 2100 121 590 21 (Bq/kg) Moriya 18Mar 26 ND (Bq/kg) Moriya 18Mar ND ND (Bq/kg) Koga 18Mar 4200 270 (Bq/kg) Sakai 18Mar 140 ND (Bq/kg) Sakai IAEA 18Mar 120 ND (Bq/kg)

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Technical Briefing on Radiological Situation in Japan - 21 March 2011

  • 1. Opening Remarks Technical Briefing (21/3/2011) 1. Current Situation We are seeing some steady improvements, but the overall situation at the Fukushima Daiichi nuclear power plant remains very serious. High levels of contamination have been measured in the locality of the plant. The restoration of electrical power to Unit 2, which we reported yesterday, is good news. AC power is available and an electrical load check to pumps etc. is currently on-going. Work on the restoration of off-site power to Units 3 and 4 is also underway. Seawater is still being injected into the reactor pressure vessels of Units 1, 2 and 3. Pressure in the reactor pressure vessel and the containment vessel drywell at Unit 3, which had been rising yesterday, has again fallen. Water is being sprayed periodically into the spent fuel pools at Units 2, 3 and 4. The Agency still lacks data on water levels and temperatures in the spent fuel pools at Units 1, 2, 3 and 4. Following the restoration of cooling at Units 5 and 6, temperatures in the spent fuel pools continue to decline. 2. Radiation Monitoring As I reported yesterday, the IAEA radiation monitoring team took measurements at distances from 56 to 200 km from the Fukushima nuclear power plant. At two locations in Fukushima Prefecture gamma dose rate and beta-gamma contamination measurements have been repeated. These measurements showed high beta-gamma contamination levels. Measurements by the IAEA and the Japanese authorities were taken at the same time and locations. The Japanese and independent IAEA measurements gave comparable results. Measurement of gamma dose rate and beta-gamma contamination were taken on 20 March at more locations. The dose-rate results ranged from 2-160 microsieverts per hour, which compares to a typical natural background level of around 0.1 microsieverts per hour. High- levels of beta-gamma contamination have been measured between 16-58 km from the plant. Available results show contamination ranging from 0.2-0.9 MBq per square metre. Further measurements are needed to assess possible contamination beyond the area currently monitored both closer to the facility and further way. We have no contamination measurements showing that that contamination levels are high at greater distances than 58 km from the plant, but this cannot be excluded. I have no further information available regarding the measurement of alpha radiation. As I reported yesterday, from the measurements taken within the evacuation zone (20 km), no significant alpha radiation had been detected at that time. In the coming days, the IAEA monitoring team will continue to take measurements in the Fukushima prefecture. We are seeking data from Japan on radioactivity contamination measurements for the rest of Japan.
  • 2. Some results on the monitoring of foodstuffs have been made available by Japan to the IAEA and FAO. Results provided recently by the Japanese authorities range up to 55,000 Bq per kg of I-131 in samples of Spinach taken in in the Ibaraki Prefecture. These high values are significantly above Japanese limits for restricting food consumption (i.e. 2,000 Bq/kg). I understand that the Japanese Government is actively considering relevant precautionary measures and has instructed four Prefectures (Ibaraki, Totigi, Gunma, Fukushima) to refrain, for the time being, from distributing two types of vegetables (spinach and kakina) from these Prefectures and milk from Fukshima. 3. Agency Activities The Director General briefed the Board of Governors today on the outcome of his visit to Tokyo.
  • 3. 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 In service auto In service auto In service auto Status at time of EQ Outage shutdown shutdown shutdown Core and fuel integrity Damaged Damaged Damaged No fuel in the Reactor RPV & RCS integrity Unknown Unknown Unknown Not applicable due to Containment integrity Not Damaged Damage suspected No information outage plant status AC Power available AC Power Substation connected Not available Not available Load check is ongoing Building Severe damage Slight damage Severe damage Severe damage Around half of Fuel is Around half of Fuel is Around half of Fuel is Water level of RPV uncovered (Stable) uncovered (Stable) uncovered (Stable) Pressure of RPV Stabilized Unreliable Readings Decreased Not applicable due to CV Pressure Drywell Stable Stable Decreased outage plant status Water injection to RPV Seawater Seawater Seawater Water injection to CV No information No information No information Periodic spraying from Periodic spraying from Periodic spraying Spent Fuel Pool Status No information outside outside from outside 3/21/2011 07:00 AM
  • 4. 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 Cold Shutdown Severe condition RPV & RCS integrity Intact Intact Containment int. No damage expected No damage expected Concern AC Power 2nd Emergency diesel from Emergency diesel Unit 6 Off-site power being restored No immediate concern Building No damage reported No damage reported Water level of RPV Above fuel Above fuel Pressure of RPV Cooling restored Cooling restored Containment Pressure No information No information Water injection to RPV Injection in Progress Injection in Progress Water injection to CV Not needed now Not needed now Spent Fuel Pool Status Cooling restored Cooling restored 3/21/2011 07:00 AM
  • 5. Technical Briefing on the Radiological Situation in Japan 21 March 2011 IAEA International Atomic Energy Agency
  • 6. Daiichi NPP On-Site gamma dose rate (updated) IAEA
  • 7. Evolution of gamma dose rates after radioactive releases surrounding Daiichi NPP since 15 March 2011 (Selected monitoring posts) IAEA Information provided by MEXT-Japan
  • 8. Gamma dose rates North of Daiichi NPP Japan (microSv/h), 15-20 March IAEA
  • 9. Gamma dose rates between Tokyo and Daiichi NPP (microSv/h), 15-20 March IAEA
  • 10. Gamma dose rates close to Tokyo, (microSv/h), 15-20 March IAEA
  • 11. Measurements by the IAEA monitoring team on 20 March 2011 Location Distanc Time,JST Doserate Alpha beta+ Contamination eto (24h) micro (counts gamma Becquerelper Mega NPP Sv/h per (countsper cm 2 Becquerel (km) second) second) perm2 MiniStopnear Kawamata Hospital 58 10:32 5.7 0 3440 58.5 0.585 NihonmatsuTowa cho 52 10:55 4.2 0 2368 40.3 0.403 Towacho Michino eki 49 11:05 3.1 0 1270 21.6 0.216 AtcrossingofRoad 349andRoad50 46 11:30 1.9 0 1973 33.5 0.335 Suichuji busstop 43 11:42 2 0 2260 38.4 0.384 JATamura 39 11:57 2.6 0 2265 38.5 0.385 Borderbetween Kuzuomura and 34 12:09 11.7 0 3152 53.6 0.536 Tamurashi Kuzuo villageoffice 29 13:47 11.2 0 4874 82.9 0.829 Road50 28 15:25 7.2 0 5030 85.5 0.855 Borderbetween Namie townand 20 14:55 161 0 overload na na Kuzuo village GateofOgakidam managementoffice 16 14:31 83 0 overload na na IAEA 7
  • 12. Measurements by the IAEA monitoring team on 19 March 2011 Location Time, Distance Dose Alpha beta+ Contamination JST from rate (counts gamma (24h) Fukushim (micro per (countsper a Sv/h) second) second) Becquerel Mega Daiichi percm2 Becquerel NPP(km) perm2 Saitama Prefecture Hasuda 17:00 200 0.04 0 27 - Tochigi Prefecture Sano 17:27 180 0.16 0 150 2.5 0.03 Kamikochi 18:17 140 0.18 0.2*) 240 4.1 0.04 Nasukogem 20:17 220 2.9 0 2300 39.3 0.39 Fukushimi Prefecture Abukuma 21:05 60 3.5 0.08*) 3750 64 0.64 Gohyakugawa 21:58 56 3 0 3900 66.3 0.66 IAEA 8
  • 13. Maps with prefectures where foodstuffs were measured IAEA 9
  • 14. Ibaraki: Results from measurements of radionuclides in foodstuffs Name SamplingDate Spniach&otherleafyvegs SpringOnion Milk(unprocessed) UNITS JST I131 Cs137 I131 Cs137 I131 Cs137 Cs134 Kitaibaraki 18Mar 24000 690 350 ND (Bq/kg) Kamisu 17Mar 56 ND (Bq/kg) Yachiyo 17Mar 78 21 (Bq/kg) Takahagi 19Mar 11,000 586 (Bq/kg) Hokota 19Mar 1900 71 (Bq/kg) Hokota 19Mar 480 81 (Bq/kg) Hitachi City 18Mar 54100 1931 (Bq/kg) Hitachi City 18Mar 25200 1105 (Bq/kg) Hitachi Omiya 18Mar 19200 1040 (Bq/kg) Hitachi Omiya 18Mar 17800 908 (Bq/kg) Naka 18Mar 16100 911 (Bq/kg) Naka 18Mar 13500 966 (Bq/kg) Hokota 18Mar 7710 407 356 9 (Bq/kg) Moriya 18Mar 2100 121 590 21 (Bq/kg) Moriya 18Mar 26 ND (Bq/kg) Moriya 18Mar ND ND (Bq/kg) Koga 18Mar 4200 270 (Bq/kg) Sakai 18Mar 140 ND (Bq/kg) Sakai IAEA 18Mar 120 ND (Bq/kg)