The world’s worst nuclear disaster in 25 years is also raising concern over safety in the United States, which has more atomic reactors than any other country, especially at one plant which is similar to the one in Fukushima wrecked by last month’s 9.0 magnitude earthquake and tsunami.
Engineers, who sealed a leak this week that had allowed highly radioactive water into the sea, are now pumping nitrogen into one reactor to prevent the risk of a hydrogen gas explosion, and want to start the process in another two reactors.
Test results for California have not yet been released, so it’s impossible to assess the exact dangers here. TheU.S. Environmental Protection Agency plans to publish those results within the next day or so, according to Mike Bandrowski, chief of indoor air and radiation for the EPA’s Region 9, which includes California.
TOKYO ELECTRIC DETECTS 5 TYPES OF RADIOACTIVITY, NHK SAYS
No surprise there: by now everyone is well aware that the fuel rods are if not completely then certainly partially destroyed. However, the real danger, and explains why we have been following atmospheric conditions over Japan so closely, is that as Kyodo just reported, the rain is now pouring radioactive cats and dogs. But the most troubling development is that instead of being proactive and finally warning its citizens about the dangers, the Japanese government has just raised the decontamination threshold by nearly 20 times from 6,000 cpm to a stunning 100,000 cpm. Is is rather safe to assume that this number was not picked arbitrarily.
Far greater amounts of radioactive iodine and cesium were found in rain, dust and particles in the air in some areas over a 24-hour period from Sunday morning due to rainfall, the science ministry said Monday.
”Considering the results of a separate test, radioactive materials in the air and drinking water are confined to levels that would not affect health,” an official of the Education, Culture, Sports, Science and Technology said. ”The impact on agricultural crops needs to be examined mainly by the Health, Labor and Welfare Ministry.”
In a notice to the nation’s 47 prefectures, the health ministry called on local governments on Monday to advise residents to stop giving babies water in forms such as baby formula if radioactive iodine is found in drinking water at levels greater than 100 becquerels per kiloliter.
”Babies can easily absorb radioactive iodine in their thyroid glands,” a ministry official said, explaining the reason for issuing the notice. The intake limit set by the central government is 300 becquerels per kiloliter of water.
The science ministry said separately traces of the substances were detected in drinking water sampled Sunday in nine prefectures but they were all below the intake limits set by the government.
The nationwide survey showed both radioactive iodine and cesium were found in Ibaraki, Tochigi and Gunma prefectures, while iodine alone was found in Saitama, Chiba, Tokyo, Kanagawa, Niigata and Yamanashi.
In Fukushima Prefecture, where the stricken Fukushima Daiichi nuclear power plant is located, the prefectural government said 23 becquerels of iodine was found per kiloliter of water.
Yamanashi appeared in the latest iodine list, after not being listed in the previous survey based on samples taken Saturday.
The health ministry has instructed water purification plants nationwide to temporarily stop taking in rainwater to prevent tap water being contaminated from radiation leaking from the crippled Fukushima No. 1 nuclear plant, ministry officials said Sunday.
While calling on the plants to keep tap water supplies stable, the Health, Labor and Welfare Ministry also proposed covering the water pools at the plants with tarps to keep rainwater out or using powdered activated carbon to help get rid of radioactive materials. The instruction came after abnormal radiation levels were found in tap water at multiple purification plants in Fukushima, Tokyo and other prefectures.
Although Tepco said late Monday the amount detected, based on soil samples taken a week ago, is extremely small and not enough to harm human health, the latest finding indicated not just heavy damage to fuel rods but also that strong radioactive materials may be leaking from at least one reactor containment vessel.
A Tepco spokesman told reporters Tuesday the utility will continue to monitor plutonium levels in the soil in the plant but has no plans to expand its checks to beyond the premises for the time being.
“Plutonium is emitted only when the temperature (inside a reactor’s core) is really high. That shows how badly (the fuel rods) were damaged and how serious this accident is,” Nuclear and Industrial Safety Agency official Hidehiko Nishiyama said Tuesday. “Still, the amount is not an immediate threat to human health.”
According to Tepco, the plutonium levels were around the same as those detected in Japan after the United States and the Soviet Union conducted nuclear tests in the past.
Radioactive material originating from the troubled Fukushima nuclear power plant in Japan has been detected at various sites in the UK – almost 6,000 miles away.
The Scottish Environment Protection Agency (SEPA) said Tuesday that an air sampler in Glasgow had recorded the presence of radioactive iodine 131 associated with events at the quake-stricken Fukushima nuclear facility. However, radiation levels were “extremely low” and should not cause any concern amongst the public.
The measured radiation level of 300 micro-becquerels per cubic metre is much lower than the natural background radiation dose in the UK and poses no harm.
The measurements were consistent with those made at other stations including one in Oxfordshire as well as locations across Europe such as Iceland and Switzerland.
The UK’s Health Protection Agency (HPA) confirmed the current radiation levels were safe. “The dose received from inhaling air with these measured levels of iodine 131 is minuscule and would be very much less than the annual background radiation dose”, the agency said in a statement. However, it added that levels of radioactive iodine “may rise in the coming days and weeks” – but clarified the concentration would still be significantly below any level that would pose a health risk.
Seoul, South Korea, March 29, 2011 /WNCNews/ – Nuclear radiation from Fukushima nuclear power plant in Japan continues to expand. After the Chinese authorities found traces of nuclear radiation from Fukushima, Japan in some areas in China, traces of radioactive iodine were also found in Seoul and other areas in South Korea.
Even, South Korean authorities have also begun to conduct examination to the fish caught in waters of the country.
The Korea Institute of Nuclear Safety (KINS) claimed to have detected traces of iodine-131 in Seoul and seven other places in South Korea. According to the South Korean agency, the amount of radioactivity which was found is very small so that it does not pose a risk to public health or the environment.
South Korean authorities have begun to examine the fish that were caught in to ensure the possibility of nuclear radiation contamination.
“No traces of radiation found so far in our fish or fish imported from Japan,” said a South Korean Agriculture Ministry official told AFP news agency on Tuesday (3/29).
He said that the South Korean government is currently testing the fish once a week. But, the frequency will be increased if the nuclear crisis in Japan continues to deteriorate.
Nor people are sure about dumping nuclear waste into the sea.
TOKYO – Workers discovered new pools of radioactive water leaking from Japan’s crippled nuclear complex, officials said Monday, as emergency crews struggled to pump out hundreds of tons of contaminated water and bring the plant back under control.
Officials believe the contaminated water has sent radioactivity levels soaring at the coastal complex, and caused more radiation to seep into soil and seawater.
The Fukushima Dai-ichi power plant, 140 miles (220 kilometers) northeast of Tokyo, was crippled March 11 when a tsunami spawned by a powerful earthquake slammed into Japan’s northeastern coast. The huge wave engulfed much of the complex, and destroyed the crucial power systems needed to cool the complex’s nuclear fuel rods.
Since then, three of the complex’s six units are believed to have partially melted down, and emergency crews have struggled with everything from malfunctioning pumps to dangerous spikes in radiation that have forced temporary evacuations.
Confusion at the plant has intensified fears that the nuclear crisis will last weeks, months or years amid alarms over radiation making its way into produce, raw milk and even tap water as far away as Tokyo.
The troubles at the Fukushima complex have eclipsed Pennsylvania‘s 1979 crisis at Three Mile Island, when a partial meltdown raised fears of widespread radiation release, but is still well short of the 1986 Chernobyl disaster, which killed at least 31 people with radiation sickness, raised long-term cancer rates, and spewed radiation for hundreds of miles (kilometers).
The spent fuel rods from a nuclear reactor are the most radioactive of all nuclear wastes. When all the radiation given off by nuclear waste is tallied, the fuel rods give off 99% of it, in spite of having relatively small volume. There is, as of now, no permanent storage site of spent fuel rods. Temporary storage is being used while a permanent site is searched for and prepared.
When the spent fuel rods are removed from the reactor core, they are extremely hot and must be cooled down. Most nuclear power plants have a temporary storage pool next to the reactor. The spent rods are placed in the pool, where they can cool down. The pool is not filled with ordinary water but with boric acid, which helps to absorb some of the radiation given off by the radioactive nuclei inside the spent rods. The spent fuel rods are supposed to stay in the pool for only about 6 months, but, because there is no permanent storage site, they often stay there for years. Many power plants have had to enlarge their pools to make room for more rods. As pools fill, there are major problems. If the rods are placed too close together, the remaining nuclear fuel could go critical, starting a nuclear chain reaction. Thus, the rods must be monitored and it is very important that the pools do not become too crowded. Also, as an additional safety measure, neutron-absorbing materials similar to those used in control rods are placed amongst the fuel rods. Permanent disposal of the spent fuel is becoming more important as the pools become more and more crowded.
Another method of temporary storage is now used because of the overcrowding of pools. This is called dry storage (as opposed to “wet” storage which we outlined above). Basically, this entails taking the waste and putting it in reinforced casks or entombing it in concrete bunkers. This is after the waste has already spent about 5 years cooling in a pool. The casks are also usually located close to the reactor site.
Permanent Fuel Storage/Disposal:
There are many ideas about what to do with nuclear waste. The low-level (not extremely radioactive) waste can often be buried near the surface of the earth. It is not very dangerous and usually will have lost most of its radioactivity in a couple hundred years. The high-level waste, comprised mostly of spent fuel rods, is harder to get rid of. There are still plans for its disposal, however. Some of these include burying the waste under the ocean floor, storing it underground, and shooting it into space. The most promising option so far is burying the waste in the ground. This is called “deep geological disposal”. Because a spent fuel rod contains material that takes thousands of years to become stable (and non-radioactive), it must be contained for a very long time. If it is not contained, it could come in contact with human population centers and wildlife, posing a great danger to them. Therefore, the waste must be sealed up tightly. Also, if the waste is being stored underground, it must be stored in an area where there is little groundwater flowing through. If ground water does flow through a waste storage site, it could erode the containment canisters and carry waste away into the environment. Additionally, a disposal site must be found with little geological activity. We don’t want to put a waste disposal site on top of a fault line, where 1000 years in the future an earthquake will occur, releasing the buried waste into the environment.
The waste will probably be encapsulated in large casks designed to withstand corrosion, impacts, radiation, and temperature extremes. Special casks will also have to be used to transfer fuel rods from their holding pools and dry storage areas next to the reactor to the permanent geological storage site.
Highly radioactive iodine seeping from Japan’s damaged nuclear complex may be making its way into seawater farther north of the plant than previously thought, officials say, adding to radiation concerns as the crisis stretches into a third week.
Mounting problems, including badly miscalculated radiation figures and no place to store dangerously contaminated water, have stymied emergency workers struggling to cool down the overheating plant and avert a disaster with global implications.
The coastal Fukushima Daiichi power plant, 220 kilometres northeast of Tokyo, has been leaking radiation since a magnitude-9.0 quake on March 11 triggered a tsunami that engulfed the complex. The wave knocked out power to the system that cools the dangerously hot nuclear fuel rods.
On Monday, workers resumed the laborious yet urgent task of pumping out the hundreds of tons of radioactive water inside several buildings at the six-unit plant. The water must be removed and safely stored before work can continue to power up the plant’s cooling system, nuclear safety officials said. That process alone could take weeks, experts say.
Already-grave conditions at the Fukushima Daiichi nuclear plant worsened Sunday with the highest radiation readings yet, compounding both the risks and challenges for workers trying to repair the facility’s cooling system.
Leaked water sampled from one unit Sunday was 100,000 times more radioactive than normal background levels — though the Tokyo Electric Power Co., which operates the plant, first calculated an even higher, erroneous, figure that it didn’t correct for several hours.
Tepco apologized Sunday night when it realized the mistake; it had initially reported radiation levels in the leaked water from the unit 2 reactor as being 10 million times higher than normal, which prompted an evacuation of the building.
After the levels were correctly measured, airborne radioactivity in the unit 2 turbine building still remained so high — 1,000 millisieverts per hour — that a worker there would reach his yearly occupational exposure limit in 15 minutes. A dose of 4,000 to 5,000 millisieverts absorbed fairly rapidly will eventually kill about half of those exposed.
Tests also found increased levels of radioactive cesium, a substance with a longer half-life, the Japanese safety agency said.
“Because these substances originate from nuclear fission, there is a high possibility they originate from the reactor,” said Hidehiko Nishiyama, the agency’s deputy director-general, at a news conference. He said that it was likely that radiation was leaking from the pipes or the suppression chamber, and not directly from the pressure vessel, because water levels and pressure in the vessel were relatively stable.