Radioactive water removal underway, fresh seawater pollution found
Mar. 28, 2011
Work to remove highly radioactive water from inside buildings at the troubled Fukushima Daiichi nuclear plant continued Monday, in an effort to enable engineers to restore the power station's crippled cooling functions, while high radioactive concentrations were again detected in the nearby sea.
The plant operator Tokyo Electric Power Co. said early Monday that the concentration of radioactive substances of a pool at the No. 2 reactor was 100,000 times higher than usual for water in a reactor core, correcting its earlier analysis of 10 million times higher.
Chief Cabinet Secretary Yukio Edano told a press conference that the highly radioactive water found at the basement of the No. 2 reactor's turbine building is ''believed to have temporarily had contact with fuel rods (in the reactor's core) that have partially melted.''
The Nuclear Safety Commission of Japan, a government panel, said Monday in its recommendations to Prime Minister Naoto Kan that highly radioactive water in the No. 2 reactor's containment vessel could have directly leaked, raising concerns that polluted water could spread to the building's underground and to the sea.
The government's Nuclear and Industrial Safety Agency also said Monday radioactive iodine-131 at a concentration 1,150 times the maximum allowable level was detected Sunday in a seawater sample taken around 1.5 kilometers north of the drainage outlets of the troubled No. 1-4 reactors.
Hidehiko Nishiyama, a spokesman for the nuclear agency, said it is highly likely that the polluted water spotted near the No. 5-6 reactors flew from the sea area near the No. 1-4 reactors along the coastline.
Nishiyama said there were no health concerns so far because fishing would not be conducted in the evacuation-designated area within 20 kilometers of the plant and radioactive materials would be ''significantly diluted'' by the time they are consumed by marine species and then by people.
Removal of highly radioactive water in the Nos. 1-4 reactors at the Fukushima plant is necessary to reduce the risk of more workers being exposed to radioactive substances. The number of workers who have been exposed to radiation exceeding 100 millisieverts at the plant came to 19 as of Monday, the utility known as TEPCO said.
Exposure to 100 millisieverts is the legal limit for nuclear plant workers dealing with an emergency, but the limit has been raised to 250 millisieverts during the ongoing crisis, the worst Japan has seen, at the plant some 220 kilometers northeast of Tokyo.
Among the 19, three received treatment at a radiation research center in Chiba Prefecture after they were exposed to radiation of 173 to 180 millisieverts Thursday. They were discharged Monday, with officials of the center saying the exposure has not affected their health.
Since Sunday, TEPCO has been trying to move the radioactive water in the basement of the No. 1 reactor's turbine building to a tank in the unit by using three pumps.
But the operator has yet to start such works at the remaining three reactor buildings due to difficulties in securing enough space at tanks to accommodate the polluted water, according to the nuclear agency.
Following TEPCO's correction of radioactive water analysis, which has undermined the credibility of the company's assessments, Edano as well as the nuclear safety agency cautioned the plant operator over its errors and instructed it to take necessary measures to avoid repeating such mistakes.
Edano said at a news conference such errors ''can never be allowed'' as radiation measurement data ''serve as the major premises to ensure safety.''
The top government spokesman also urged evacuees from the 20-km exclusion area around the plant not to temporarily return home to collect household belongings, citing ''great risks of radiation contamination'' in the zone.
Earlier in the day, a strong earthquake with a preliminary magnitude of 6.5 jolted Miyagi Prefecture and its vicinity in northeastern Japan, but TEPCO said the quake was unlikely to affect work to restore the reactors' key cooling functions.
(Distributed by Kyodo News on March 28, 2011)
The plant operator Tokyo Electric Power Co. said early Monday that the concentration of radioactive substances of a pool at the No. 2 reactor was 100,000 times higher than usual for water in a reactor core, correcting its earlier analysis of 10 million times higher.
Chief Cabinet Secretary Yukio Edano told a press conference that the highly radioactive water found at the basement of the No. 2 reactor's turbine building is ''believed to have temporarily had contact with fuel rods (in the reactor's core) that have partially melted.''
The Nuclear Safety Commission of Japan, a government panel, said Monday in its recommendations to Prime Minister Naoto Kan that highly radioactive water in the No. 2 reactor's containment vessel could have directly leaked, raising concerns that polluted water could spread to the building's underground and to the sea.
The government's Nuclear and Industrial Safety Agency also said Monday radioactive iodine-131 at a concentration 1,150 times the maximum allowable level was detected Sunday in a seawater sample taken around 1.5 kilometers north of the drainage outlets of the troubled No. 1-4 reactors.
Hidehiko Nishiyama, a spokesman for the nuclear agency, said it is highly likely that the polluted water spotted near the No. 5-6 reactors flew from the sea area near the No. 1-4 reactors along the coastline.
Nishiyama said there were no health concerns so far because fishing would not be conducted in the evacuation-designated area within 20 kilometers of the plant and radioactive materials would be ''significantly diluted'' by the time they are consumed by marine species and then by people.
Removal of highly radioactive water in the Nos. 1-4 reactors at the Fukushima plant is necessary to reduce the risk of more workers being exposed to radioactive substances. The number of workers who have been exposed to radiation exceeding 100 millisieverts at the plant came to 19 as of Monday, the utility known as TEPCO said.
Exposure to 100 millisieverts is the legal limit for nuclear plant workers dealing with an emergency, but the limit has been raised to 250 millisieverts during the ongoing crisis, the worst Japan has seen, at the plant some 220 kilometers northeast of Tokyo.
Among the 19, three received treatment at a radiation research center in Chiba Prefecture after they were exposed to radiation of 173 to 180 millisieverts Thursday. They were discharged Monday, with officials of the center saying the exposure has not affected their health.
Since Sunday, TEPCO has been trying to move the radioactive water in the basement of the No. 1 reactor's turbine building to a tank in the unit by using three pumps.
But the operator has yet to start such works at the remaining three reactor buildings due to difficulties in securing enough space at tanks to accommodate the polluted water, according to the nuclear agency.
Following TEPCO's correction of radioactive water analysis, which has undermined the credibility of the company's assessments, Edano as well as the nuclear safety agency cautioned the plant operator over its errors and instructed it to take necessary measures to avoid repeating such mistakes.
Edano said at a news conference such errors ''can never be allowed'' as radiation measurement data ''serve as the major premises to ensure safety.''
The top government spokesman also urged evacuees from the 20-km exclusion area around the plant not to temporarily return home to collect household belongings, citing ''great risks of radiation contamination'' in the zone.
Earlier in the day, a strong earthquake with a preliminary magnitude of 6.5 jolted Miyagi Prefecture and its vicinity in northeastern Japan, but TEPCO said the quake was unlikely to affect work to restore the reactors' key cooling functions.
(Distributed by Kyodo News on March 28, 2011)
