March 27, 2011
TOKYO: Radiation in seawater inside quake-damaged reactors at the Fukushima Daiichi power plant might be rising, Japan's nuclear watchdog said yesterday.
Radiation levels showed signs of climbing, Nuclear and Industrial Safety Agency spokesman Hidehiko Nishiyama said.
Readings of between 200 and 300 millisieverts per hour were recorded in water at the No. 2 reactor, he said, equivalent to the maximum exposure permitted for workers during the crisis.
Advertisement: Story continues below Repairs focused on restoring power and cooling fuel rods at the site of the worst nuclear disaster since Chernobyl have been hampered by explosions and radiation leaks. Yesterday the Tokyo Electric Power Company switched to fresh water for dousing the No. 1 and No. 3 reactors to avoid further corrosion.
Radioactive nuclides including caesium-136 and yttrium-91 were found in water at the turbine building of No. 1 reactor, the nuclear agency said on its website yesterday.
Two workers suffered radiation burns to their legs on Thursday from stepping in water at the No. 3 unit, which indicated a possible breach to the reactor core, it said.
''We're trying to prevent a deterioration of the situation,'' Prime Minister Naoto Kan said in a public address on Friday evening. ''We must continue to work with a high sense of alertness.''
The nuclear agency said it did not believe there was a crack in the pressure vessel or containment vessel around the core at the No. 3 reactor.
On Friday the government advised more people living close to the nuclear site to evacuate because basic goods were in short supply, while assuring them that radiation levels had not risen.
The death toll from the quake and tsunami rose to 10,151, with 17,053 people missing, according to the National Police Agency in Tokyo.
The spread of radiation to food and water supplies prompted bulk-buying of bottled drinks.
Bloomberg
_____________
Japan: UN agencies offer food safety help in nuclear contamination crisis
Nuclear power plant in Fukushima, Japan, experienced system failure after the massive quake and tsunami
23 March 2011 – United Nations agencies today pledged their “knowledge and expertise” to help Japan tackle food safety issues arising from radioactive contamination spewed out by the nuclear power plant that was severely damaged by a devastating earthquake and tsunami 12 days ago.
In joint documents issued in response to “some of the growing international concerns over the safety of food produced in Japan,” the Food and Agriculture Organization (FAO), International Atomic Energy Agency (IAEA) and World Health Organization (WHO) said that while some foods produced in Japan are likely to be contaminated by radionuclides at levels unsuitable for human consumption, there is no evidence food has been contaminated in any other country.
“Since the events of 11 March, thousands of lives have been lost, and many homes and buildings have been damaged or destroyed by the earthquake and tsunami,” said a statement issued by FAO Director General Jacques Diouf, IAEA Director General Yukiya Amano and WHO Director General Margaret Chan. “Food safety issues are an additional dimension of the emergency.”
The agencies noted that radioactivity from the stricken Fukushima Daiichi power plant has been detected in some vegetables and milk, with radioactive iodine present in concentrations above Japanese regulatory limits and caesium showing up at lower concentrations.
Radioactive iodine, the main contaminant detected so far, can accumulate in the body, of ingested, particularly the thyroid gland, increasing the risk of thyroid cancer, particularly in children. But it has a half-life of eight days and decays naturally within weeks. Taking potassium iodide is an established method to prevent the accumulation of radioactive iodine in the thyroid.
Ingestion of food contaminated with radioactive caesium can have long-term health effects. In contrast to radioactive iodine, it can linger in the environment for many years and present a longer-term problem for food production, threatening human health. The situation has to be monitored carefully, the agencies said.
General advice to food consumers and producers include protecting food and animal fodder stored in the open by covering them with plastic impermeable tarpaulins; closing ventilation in greenhouses; bringing livestock in from pastures and move them into barns; and harvesting ripe crops and covering them before fallout has been recorded; after which they should not be harvested.
The agencies advise that people avoid the following longer-term actions in areas confirmed to be seriously contaminated: consuming locally produced milk or vegetables; slaughtering animals; consuming and harvesting aquatic animals and plants, including fish, shellfish, and algae; hunting; and gathering mushrooms or other wild or collected foods.
In a daily briefing on the crisis, IAEA Special Adviser on Scientific and Technical Affairs Graham Andrew cited some positive developments with regard to electrical power, which is now available at units one, two and four; while unit three has lighting but no power for its equipment or instruments. Power lines and emergency diesel back-up engines were knocked out by the quake and tsunami.
As in the past, he said no significant risk to human health has so far been identified, but warned that the overall situations “remains of serious concern.” A second IAEA monitoring team in now on the ground to help check on radiation.
News Tracker: past stories on this issue
Japan: UN reports some improvements in ‘still very serious’ nuclear crisis
________________
Japan: UN reports some improvements in ‘still very serious’ nuclear crisis
IAEA Special Adviser on Scientific and Technical Affairs Graham Andrew
22 March 2011 – The United Nations agency that coordinates global nuclear safety today reported “some improvements” in the Japanese nuclear power plant crisis, but warned that the overall situation remains very serious and said it had not received information on certain crucial aspects.
“High levels of contamination have been measured in the locality of the plant… The highest concern remains the spent fuel in the storage ponds of each reactor unit, particularly unit four,” International Atomic Energy Agency (IAEA) Special Adviser on Scientific and Technical Affairs Graham Andrew told a news briefing at agency headquarters in Vienna on the crisis spawned by the earthquake- and tsunami-stricken Fukushima Daiichi power plant.
“Reactors one to three remain of concern, particularly unit two. We have not received validated information for some time related to the containment integrity of unit one so we are concerned that we do not know its exact status,” he said, adding that no information is available for the spent fuel pool of unit one and the agency still lacks data on water levels and temperatures in the spent fuel pools at units one, three and four.
Japanese emergency workers are racing to restore water cooling systems to prevent a total meltdown of the fuel rods and a major release of radioactive plumes in the worst civilian nuclear crisis since the deadly Chernobyl power plant explosion in the then Soviet Union 25 years ago. They have pumped in sea water, sprayed additional water from helicopters, and have now reconnected electricity power that was knocked out by the quake.
Mr. Andrew said IAEA continues to receive data about high radiation levels in food, notably spinach, in samples taken in 37 locations in five cities to the south of Fukushima. “This indicates that in four prefectures some food products are above permissible levels,” he noted.
An IAEA radiation monitoring team took measurements at additional locations between 35 and 68 kilometres from the plant, and it plans to have two teams up and running in the coping days, one in the Fukushima area and one in Tokyo and surrounding areas.
Mr. Andrew began his briefing by saying: “There continue to be some improvements at the Fukushima Daiichi power plant but the overall situation remains very serious.”
Positive developments he cited concerned units five and six, which were already in cold shut down. Offside power is now is now being used in unit five, the pressure of the reactor pressure vessel of both units has decreased and water is being injected into the reactor pressure vessel as needed, he noted.
On the ground in Japan, the UN World Food Programme (WFP) has launched a logistics operation to support the Government’s delivery of relief items to victims of the devastating 11 March quake and tsunami, which killed some 10,000 people, with a further 13,000 still missing, according to media reports.
WFP’s experts are helping to move relief items swiftly to the areas that were laid waste by the enormous waves, where some 350,000 people are estimated to be staying in 2,100 shelters. The agency is also arranging the delivery of mobile warehouses to store relief items to help those worst affected by the disaster.
News Tracker: past stories on this issue
Nuclear emergency response must be upgraded in light of Japanese crisis – UN atomic chief
No comments:
Post a Comment