Inquiry launched into nuclear disaster as studies reveal contamination more widely spread than first thought
by Justin McCurry
TOKYO – The amount of radiation released by the Fukushima Daiichi nuclear power plant in the days after the 11 March tsunami could have been more than double that originally estimated by its operator, Japan’s nuclear safety agency has said.
By the end of last week, radiation levels inside the reactor had risen to 4,000 millisieverts per hour, the highest atmospheric reading inside the plant since the disaster.
In a possible sign that the contamination is more widespread than previously thought, a university researcher said at the weekend a small amount of plutonium had been identified a mile from the front gate of the Fukushima plant.
Denis Flory, deputy director of the IAEA, said that his primary concern was to rebuild public confidence in nuclear power following the disaster at Fukushima.
The report praised the openness of the Japanese government and TEPCO in “answering the many questions of the mission to assist the world in learning lessons to improve nuclear safety.”
The report stressed that there had been no recorded health effects from the release of radioactive material from Fukushima. It states: “To date, no health effects have been reported in any person as a result of radiation exposure from the nuclear accident.”
The health of workers on site was being safeguarded by “highly-professional back up”, the report claims.
The preliminary report merely refers to “severe damage of the fuel”. But TEPCO, which owns the stricken Fukushima plant, admitted last month that a meltdown took place in three of the reactors soon after the tsunami hit the plant, knocking out emergency power systems. A triple meltdown has never happened at any other nuclear facility.
“The problem is that too much policy has been focused on protecting TEPCO and not enough on the public”, said Dr. Kiyoshi Kurakawa, who was previously a Japanese government health adviser.
- his primary concern was to rebuild public confidence in nuclear power
- IAEA admits that its concern lies with the future of the nuclear power industry and not with human lives or the health of the Japanese biosystem or that of the planet.
- praised the openness of the Japanese government and TEPCO
- The results of the soil survey show that dangerous levels of contamination have spread beyond the official exclusion established by the Japanese government around the Fukushima plant. Levels of contamination inside the exclusion zone are not known because only government scientists are allowed access. They have not published the results of any tests on soil contamination.
- no health effects have been reported in any person
- The full extent of the workforce’s exposure to radiation is not known. Workers involved in the recovery operations are still not subject to routine testing. Some 7,800 workers have been employed at Fukushima since the disaster, but only 1,800 have been checked for radiation exposure, according to the newspaper Asahi Shimbun.
- The health of workers on site was being safeguarded
- Two male workers, one in his 30s and the other in his 40s, have been exposed to more than the 250 millisieverts level legally allowed for nuclear workers in Japan. The government raised the limit from its previous level of 100 millisieverts after the disaster. Exposure to more than 100 millisieverts of radiation is thought to increase the lifetime risk of developing cancers.
Previously, three workers were found to have been exposed to over 1000 millisieverts after working in flooded tunnels under the Fukushima plant. This new revelation points once again to the dangers faced by workers on the site.
The IAEA is obviously working in the interests of the nuclear industry, as are the Japanese government, TEPCO, and the MSM worldwide, and all are purposefully ignoring the ever increasing threat to human lives in Japan and to the Japanese and oceanic biosphere.
At the same time, waterborne contamination is continuing. The water that has flooded the trenches and underground tunnels at the Fukushima plant is thought to be more heavily contaminated than that released into the atmosphere.
The water is reaching maximum depths and is expected to start overflowing within the next few days. Alternative storage and treatment facilities have still not been completed. A decontamination plant is unlikely to be ready until June 15 and an underground storage facility for contaminated water is scheduled to be completed by mid-August. Even when it is finished, the storage unit will be inadequate. There are already 105 million litres of radioactive water on the site and the storage tank will take only 10 million litres.
Water levels are rising because Japan is in its rainy season. Typhoon Songda, which recently passed through the area, increased the levels of water at the Fukushima plant dramatically. “We may have between five and seven days before the water levels reach the top of the trenches,” Hikaru Kuroda, a TEPCO spokesperson said. The Bloomberg news agency was sceptical of this projected timeframe and suggested the overflow could begin as early as June 6.
Quite apart from the risk of overflow, radioactive water is still leaking into the sea. By April 5, 10 million litres of contaminated water had been dumped into the sea. Efforts to fix a leak have not been successful. Fish in the waters off the plant have been found to contain dangerously high levels of caesium.
Tokyo – High levels of radioactive materials were detected on the Pacific seabed in a 300-kilometer stretch off a damaged nuclear plant in north-eastern Japan, news reports said Saturday.
The government said radioactive materials up to several hundred times higher than normal were found ranging from Miyagi prefecture to Chiba prefecture and warned that the contamination could affect the safety of seafood.
The science ministry detected iodine and caesium on the seabed at a dozen locations 15 to 50 kilometres from the coast between May 9 and 14, the Kyodo News agency reported.
Since the Fukushima Daiichi Nuclear Power Station was crippled by a magnitude-9 earthquake and tsunami on March 11, it has leaked radioactive materials into the environment.
The effort to regain control of the plant relies on pumping massive quantities of water to cool the three reactors that suffered meltdowns and storing the contaminated water in an improvised storage facility. Tepco officials said, however, that the water level in the storage facility had dropped, suggesting a leak.
Unit 1′s containment is leaking. They can’t put nitrogen into it to maintain it’s pressure. Unit 2′s has been leaking and filling trenches off site. Unit 3′s is now leaking as well and filling trenches off away from the reactor. So all three nuclear containments are leaking… Unit 4 is leaning. The structure is… tilting at the top and that’s not good. If there is a seismic aftershock as a result of the first earthquake, Unit 4 could collapse… [a]nd finally, all the reactors are continuing to emit radiation. The containments have failed. So it’s going down as water and it’s going up in steam and there is no plan in site to prevent that from happening in the future.
…[T]he situation at the Fukushima Dai-ichi nuclear plant in Japan remains, in the words of the International Atomic Energy Agency’s weekly bulletin, “very serious”.
Workers entered the reactor building last week… in order to restore ventilation and reduce the ongoing high levels of radiation inside the structure. Having achieved those initial steps, engineers repaired an important gauge used to measure water levels inside the reactor’s pressure vessel.
Previous readings had shown the water level at 1.6 metres below the top of the fuel rods in the reactor core. As it turned out, these measurements were false. The actual water level was five metres below the top of the fuel rods, leaving them fully exposed.
At the same time, temperature readings inside the pressure vessel have stabilised at between 100 and 120 degrees centigrade. If the fuel rods were still largely in place, the temperature would be far higher. As a result, TEPCO engineers now believe that at the height of the crisis, when the reactor’s cooling systems failed, molten fuel fell to the bottom of the pressure vessel.
TEPCO has been pumping water into the pressure vessels of reactors 1, 2 and 3 for weeks in a bid to lower temperatures. The low level of water in reactor 1 indicates that the molten fuel might have created a hole in the bottom of the steel pressure vessel.
TEPCO general manager Junichi Matsumoto told a press conference yesterday: “There must be a large leak… The fuel pellets likely melted and fell, and in the process may have damaged… the pressure vessel itself and created a hole.”
The situation could be far worse if some of the molten fuel has fallen through the pressure vessel into the base of the reactor’s primary containment vessel—a thick concrete structure that surrounds the steel pressure vessel.
US nuclear expert Gene Corley told Reuters: “If it is assumed the fuel did melt through the reactor, then the most likely solution is to encapsulate the entire unit. This may include constructing a concrete wall around the unit and building a protective cover over it. Because of the high radiation that would be present if this has happened, the construction will take many months and may stretch into years.”
In comments to Bloomberg.com, American physicist Paul Padley said: “What this means is this is probably going to be a much more difficult cleanup than they originally planned for… [they] have consistently appeared to be underestimating the severity of the situation”.
The discovery of the faulty water gauge highlights the fact that engineers working to stabilise the reactors at the Fukushima plant still do not know the full scale of the disaster…
Late last month, TEPCO revised its estimates of the damage to the reactor cores as follows: for reactor 1, it was lowered from 70 to 55 percent; for reactor 2, it was raised from 30 to 35 percent; and for reactor 3, from 25 to 30 percent. In light of the latest information, the figure for unit 1 will have to be lifted sharply, and the estimates for the other two reactors are just as dubious. Workers have yet to enter reactors 2 and 3, where extensive damage has also taken place.
Last month TEPCO was compelled to take emergency measures to prevent highly radioactive water in a maintenance trench associated with reactor 2 from spilling into the sea. The source is still not known.
On Wednesday, TEPCO announced that it had sealed a new leak, near a seawater intake, of highly contaminated water found in a pit associated with reactor 3. It was not clear where the water had come from or if it had been leaking into the sea.
[W]orkers were sent back into building 1 for the first time since 11 March. Twelve engineers worked in shifts of 10 minutes for about an hour. The intention is to re-establish the reactor’s cooling system.
Shortly after it was announced that workers had been sent into the plant, TEPCO admitted that the radiation levels in building 1 were 700 millisieverts per hour. This was far higher that had been anticipated on the basis of earlier readings taken by robots.
The source of the high levels of radiation is not known. Video of the inside of the plant taken by the robots confirmed that there were no water leaks.
The threat is not confined to those on site. The effect of opening up building 1 was to release large amounts of radioactivity into the atmosphere…
Arnie Gundersen of Fairewinds Associates in the US, a nuclear engineer who served as an expert witness in the investigation of the Three Mile Island accident, has warned that while the major leak allowing contaminated water to enter the sea has been plugged other leaks continue. Ground water contamination is continuing and it appears to be moving northwards in the water table. Fukushima, Gundersen predicts, may well prove to be the worst example of ground water contamination in nuclear history.
In a recent video Gundersen noted that radioactivity has been detected in sewage sludge from the Fukushima area, suggesting that contamination from groundwater or rainwater runoff is now extensive. Some of this sludge has been incorporated into cinder blocks that are used as building material and have been shipped out of the area, widening the possible zone of contamination.
Workers have entered the Unit 1 reactor building of Japan’s damaged Fukushima Daiichi nuclear plant for the first time since a hydrogen explosion hit the facility a day after the devastating March earthquake and tsunami.
Twelve staff members stepped in to install duct pipes to six ventillation machines that will filter out the radioactive material in the air, Tokyo Electric Power Company (TEPCO), the plant operator, said on Thursday.
“Groups of four will go in one by one to install the ducts. They’ll be working in a narrow space,” Junichi Matsumoto, TEPCO’s spokesman, said.
High radiation levels inside the plant have kept workers from entering the facility to repair the plant’s cooling systems. No one has entered the reactor building since the March 12 explosion.
The workers, equipped with protective suits, masks and air tanks, went through a special tent set up at the entrance to prevent radiation leaks.
They will work for 10 minutes inside the building. The operation is expected to take about four or five days.
Robots sent into the Number 1 reactor building have recorded the highest reading of radioactivity so far found at the Fukushima Dai-ichi plant since the emergency began almost two months ago. Two robots found 1,120 millisieverts of radiation an hour was being emitted from the stricken reactor. This level of radiation is more than enough to cause immediate radiation sickness if a human being were exposed to it. The Tokyo Electrical Power Company (Tepco) which runs the Fukushima facility has begun to use robots because it has become impossible to send workers into the plant for long enough to take accurate readings.
View Google Map click on the blue markers above for news specific to reactors 1,2,3 and 4
26 April 2011 – The damage to the cores of units 1, 2 and 3 is still unknown; the normal reactor cooling systems are not operating; large amounts of highly radioactive water still have to be removed.
Efforts to stabilise the reactors are being impeded by large amounts of highly radioactive water.
In all, TEPCO has to remove an estimated 67,500 tonnes of water from the three damaged units. It has to find safe places to store the radioactive water before it is treated by a processing plant being built by the French nuclear corporation Areva. The construction of the Areva unit is likely to take at least two months.
The removal of the contaminated water is a first step to restarting the plant’s power supply and cooling systems. According to NISA spokesman Nishiyama, however, TEPCO is also considering a potentially faster alternative to bring down the reactor temperatures—installing an air-cooling system rather than repairing the existing water-cooling system.
I think there can be an end to our troubles. The first step in Thailand is voting out the Thai Army which, in addition to its massacres and aggressive wars, ‘authorized’ the construction of two nuclear reactors in Thailand, which the amaat is dutifully following through on now, even as we weep.
At Fairwind Associates Gundersen Postulates Unit 3 Explosion May Have Been Prompt Criticality in Fuel Pool, which would account for the anomalous high reading of 50µSv/hr near a kindergarten playground around Koriyama detected by Safecast in their first mobile outing : pieces of the plutonium/uranium fuel expelled by the explosion of the spent fuel from reactor unit 3 may be spread all around the area.
Fifty microsieverts per hour amounts, over the course of a year, to more than four times the annual radiation limit allowed for reactor workers prior to the explosion, when the Japanese government arbitrarily multiplied that level by two and a half.