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Nuclear events taking place in Japan.

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GeordieBoy

Sat Mar 26 2011, 10:40PM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

Well, I'd say when a nuclear plant explodes, catches fire, three different colours of smoke are coming from a hole in the wreckage about where the spent fuel pool is, and everyone is wading around in radioactive water, the situation has become really bad.

I'd agree.

This is all getting quite worrying. My brother lives with his partner in Tokyo, and i've visited Japan several times.

Aftershocks are still a daily occurance there and much of the mobile phone network is still down. He managed to get his first pint of milk in over a week the other day! Japan is a beautiful country with fantastically resourceful people and it is very sad to see what has and is continuing to happen there. I just wish their collective minds and those of the flown-in nuclear experts could come up with a solution to draw this catastrophe to an end as quickly as possible.

For what it's worth this is a common source of english news for UK citizens in Jpn:

I don't know how this compares with other sources of info, metely adding it to the list.

-Richie,

Proud Mary

Sun Mar 27 2011, 10:11AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Japan nuclear plant: workers evacuated after radiation levels soar

Tests at Fukushima No 2 reactor reveal radiation at 10 million times normal levels amid warnings crisis could last months

Justin McCurry in Tokyo
guardian.co.uk,
Sunday 27 March 2011

Radioactivity levels in one part of the stricken Fukushima Daiichi nuclear plant are 10 million times higher than normal, Japanese officials have said, amid warnings that the operation to avert disaster at the facility could last for months..

Tests on the surface of a pool of water that has formed in the No 2 reactor revealed radioactivity of 1,000 millisieverts (mSv) per hour â€“ four times the level deemed safe by the government. The worker carrying out the test reportedly fled before taking a second reading.

Hidehiko Nishiyama, a spokesman for Japan's nuclear and industrial safety agency [Nisa], said, "This is quite a high figure," adding that the water "is likely to be coming from the reactor".

The discovery prompted another evacuation of workers at the site, halting work to pump and store radioactive water that has built up in the turbine buildings of three of the plant's six reactors.

Evidence of dangerous contamination in the No 2 reactor emerged after three workers were exposed to high levels of radioactivity while repairing the cooling system at the No 3 reactor. Two of the men received suspected beta ray burns after stepping into water with radiation levels 10,000 times higher than normal. Reports said the workers were due to be discharged from hospital on Monday.

Modest progress was made over the weekend to remove contaminated water and step up work to cool the reactors with fresh water, rather than corrosive seawater. But Yukiya Amano, the director general of the International Atomic Energy Agency (IAEA), warned that Japan's nuclear emergency could go on for weeks, and possibly months. "This is a very serious accident by all standards," he told the New York Times. "And it is not yet over."

With just one pump currently being used to extract radioactive water, two more will be taken to the site, while the US military is also sending barges loaded with 500,000 gallons of fresh water to nearby Onahama Bay, the US 7th fleet said.

Two of the six reactors at the plant, owned and operated by Tokyo Electric Power (Tepco), are considered safe, having achieved "cool shutdown", but the remaining four have yet to be brought under control. Nisa said that temperature and pressure inside all six reactors had stabilised.

The unusually high levels of radioactivity in the puddles "almost certainly" indicated that water had seeped from a reactor core, Yukio Edano, the chief government spokesman. Edano denied the situation was deteriorating, but conceded that the myriad problems facing the power plant workers were no closer to being resolved.

"We are preventing the situation from worsening," he said. "We have restored power and pumped in fresh water, and we are making basic steps towards improvement. But there is still no room for complacency."

The deterioration in the state of the reactors is the latest in a string of complications to have hit the Fukushima operation since the plant was seriously damaged by the 11 March earthquake and tsunami along Japan's north-east coast.

The nuclear crisis has raised fears about the safety of food in the area, while Tokyo, 150 miles to the south, experienced a brief rise in radioactivity in tap water that prompted a one-day ban on consumption by infants.

Bans have been imposed in the shipment of milk and leafy vegetables from the Fukushima region, while several countries introduced restrictions on Japanese food imports. Last week, the US became the first country to ban the import of milk and some vegetables from contaminated areas.

Growing concern over food safety spread to the fishing industry over the weekend, when officials said seawater samples taken 30km off the coast of the Fukushima plant contained 1,850 times the normal level of radioactivity. But Nisa said the tainted seawater posed no risk to health. "Ocean currents will disperse radiation particles and so it will be very diluted by the time it is consumed by fish and seaweed, and even more by the time they are consumed by humans," Nishiyama said. "There is no need to worry about health risks,"

Officials said on Friday they suspected one or more of the reactors had been damaged, leading to water leakages and raising the possibility of large amounts of radiation finding their way into the environment. Tepco has yet to determine the source of the leak.

A Nisa spokesman said the length of time workers spend inside units is being closely monitored. "It is definitely a severe environment, but the amount of time workers are allowed in there is strictly controlled so that their exposure does not exceed the limit," Minoru Ogoda said. He added that most of the radioactivity found in the No. 2 came from iodine-134. The substance has a half-life of just 53 minutes, meaning it dissipates quickly.

The setbacks have fueled criticism of Tepco's handling of the crisis in recent days, and heightened concerns over the safety of up to 600 workers at the plant. The government urged the company to be more transparent after it emerged that Tepco knew radiation levels had risen dramatically days before the workers were injured.

"Regardless of whether there was an awareness of high radioactivity in the stagnant water, there were problems in the way work was conducted," Nishiyama said.

The men were exposed to radiation of between 173 and 180 mSv, lower than the upper limit of 250 mSv per year introduced by the health ministry soon after the disaster.

Steve Conner

Sun Mar 27 2011, 10:53AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Martin King wrote ...

Another article that tries to put things into poerspective

The Radiation and Reason guy does have a point. There are so many other environmental carcinogens (many of which are caused by other industries, but that's beside the point) and even if there weren't, you have a chance of getting cancer anyway. Occasional DNA corruption is a fact of life, and the self-repair/self-destruct mechanism evolved to handle it isn't quite 100% effective. I suppose the problem is that the protection mechanism is necessarily a piece of DNA code itself.

I've seen it said that the health effects of the panic and disruption caused by mass evacuations at Chernobyl were orders of magnitude worse than the effects of the actual radiation. For a real nasty nuclear event, you have to look at the Kyshtym disaster of 1957: the radioactive release was less than Chernobyl, but because the top-secret plant wasn't even supposed to exist, the Soviets never bothered to tell anyone that it blew up. In 1968, the contaminated area was cynically designated as a "nature reserve".

However, as a die-hard hippie I think the strict limits on radioactive emissions are good to stop the nuclear industry getting too successful.

If they could just throw spent nuclear fuel into a pit in the back yard, the cost of nuclear power would plummet.

Here's a link to the World Nuclear Association technical report:

Ash Small

Mon Mar 28 2011, 12:16AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

I hear they've had to pull the workers out due to high radiation levels at reactor two.

If this continues the situation could get serious. Without cooling things will only get worse. Even if there isn't an explosion releasing plutonium etc into the atmosphere, how long will it be before it gets into the drinking water supply?

19.00 GMT: Plutonium found in the soil surrounding the reactors.

Proud Mary

Tue Mar 29 2011, 11:39AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Japan nuclear plant: plutonium found in Fukushima soil
Plutonium has been detected in soil samples taken from around the crippled Fukushima nuclear plant, reinforcing fears that the operator of the facility still does not have a firm grasp of scale of the problem.

By Julian Ryall, in Tokyo
Telegraph co.uk
29 Mar 2011

Tokyo Electric Power Co has said that it was not clear where the plutonium has come from but that the levels of plutonium 238, 239 and 240 were not in concentrations that are dangerous to human health.

He added that emergency teams trying to bring the four damaged reactors under control were still working.

"I apologise for making people worried," Sakae Muto, vice president of the company, said at a press conference in Tokyo.

"It is not at levels that are harmful to human health."

As well as being used in nuclear reactors, plutonium 239 is used in the production of nuclear weapons and has a half-life of more than 24,000 years.

Experts fear the plutonium may have come from spent fuel rods that were stored in pools at the plant. The March 11 earthquake and tsunami damaged the pools and exposed the rods, which rapidly surpassed safe temperature levels. Alternatively, the plutonium may be leaking from reactor No. 3, the only one at the plant that uses the element.

The Japanese government has already confirmed that levels of radioactivity in water seeping from the plant are 100,000 times normal levels. Elevated levels of radioactivity have already been found in the ocean close to the facility and in vegetables in prefectures surrounding the plant.

The Nuclear and Industrial Safety Agency has vowed to increase monitoring in the plant and beyond the 12-mile exclusion zone imposed by the government around the nuclear facility.

And while it remains unclear just how serious this latest discovery is, NISA officials have stated that the detection of plutonium at the site indicates there has been "certain damage to fuel rods."

Hidehiko Nishiyama, a spokesman for the agency, told Kyodo News that it is "deplorable" that accident safeguards at the plant had failed so dramatically.

Traces of radioactivity from the stricken plant have been found in rain that has fallen in the northeast United States, although authorities there have been quick to point out that the levels are "very low," as well as across large swathes of southeastern China and in South Korea.

In northern Japan, which bore the brunt of the earthquake and tsunami, the death toll has surpassed the 11,000 figure with a further 17,339 listed as missing.

According to police overseeing the recovery of the dead, more than 4,000 bodies found in the shattered remains of towns and villages along the north-east coast have still to be identified.

Proud Mary

Tue Mar 29 2011, 06:26PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Japan may have lost race to save nuclear reactor

Fukushima meltdown fears rise after radioactive core melts through vessel â€“ but 'no danger of Chernobyl-style catastrophe'

* Ian Sample , science correspondent
* guardian.co.uk, Tuesday 29 March 2011 16.53 BST

The radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor below, experts say, raising fears of a major release of radiation at the site.

Richard Lahey, who has worked on the plant at Fukushima, told the Guardian officials seemed to have "lost the race" to save the reactor, but added that there was no danger of a Chernobyl-style catastrophe.

His warning came as Nick Clegg, the deputy prime minister, signalled that Britain could take a step back from nuclear power in the wake of the disater.

Speaking on a trip to Mexico, Clegg said the resulting uncertainty for the nuclear industry could make it more likely the industry would need a public subsidy, which the coalition would be unable to provide.

"We have always said there are two conditions for the future of nuclear power [the next generation of power stations] have to be safe and can not let the taxpayer be ripped off," he said.

Eight new nuclear plants are due for construction in the UK.

Meanwhile the Health Protection Agency said that traces of radioactivity believed to come from the Fukushima disaster had been detected across the UK by emergency monitoring stations in Oxfordshire and Glasgow.

The agency that "the minutest" levels of radioactive iodine had been detected at its air monitoring stations over the last nine days, but they posed no risk to health.

At Fukushima, workers have been pumping water into three reactors in a desperate bid to keep the fuel rods from melting down. But Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at the plant, said his analysis of radiation levels suggested these attempts had failed at reactor two.

He said at least part of the molten core, which includes melted fuel rods and zirconium alloy cladding, seemed to have sunk through the steel "lower head" of the pressure vessel and on to the concrete floor below.

"The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell," Lahey said. "I hope I am wrong, but that is certainly what the evidence is pointing towards."

The major concern when molten fuel breaches a containment vessel is that it will react with the concrete floor of the drywell, releasing radioactive gases into the surrounding area. At Fukushima, the drywell has been flooded with seawater, which will cool any molten fuel that escapes from the reactor and reduce the amount of radioactive gas released.

Lahey said: "It won't come out as one big glob; it'll come out like lava, and that is good because it's easier to cool."

The drywell is surrounded by a secondary steel-and-concrete structure designed to keep radioactive material from escaping into the environment. But an earlier hydrogen explosion at the reactor may have damaged this.

"The reason we are concerned is that they are detecting water outside the containment area that is highly radioactive and it can only have come from the reactor core," Lahey added. "It's not going to be anything like Chernobyl, where it went up with a big fire and steam explosion, but it's not going to be good news for the environment."

The radiation level at a pool of water in the turbine room of reactor two was measured recently at 1,000 millisieverts per hour. At that level, workers could remain in the area for just 15 minutes, under current exposure guidelines.

A less serious core meltdown happened at the Three Mile Island nuclear plant in Pennsylvania in 1979. During that incident, engineers managed to cool the molten fuel before it penetrated the steel pressure vessel. The task is a race against time, because as the fuel melts it forms a blob that becomes increasingly difficult to cool.

In the light of the Fukushima crisis, Lahey said all countries with nuclear power stations should have "Swat teams" of nuclear reactor safety experts on standby to give swift advice to the authorities in times of emergency, with international groups co-ordinated by the International Atomic Energy Authority.

The warning came as the Japanese authorities were being urged to give clearer advice to the public about the safety of food and drinking water contaminated with radioactive substances from Fukushima.

Robert Peter Gale, a US medical researcher who was brought in by Soviet authorities after the Chernobyl disaster, in 1986, has met Japanese cabinet ministers to discuss establishing an independent committee charged with taking radiation data from the site and translating it into clear public health advice.

"What is fundamentally disturbing the public is reports of drinking water one day being above some limit, and then a day or two later it's suddenly safe to drink. People don't know if the first instance was alarmist or whether the second one was untrue," said Gale.

"My recommendation is they should consider establishing a small commission to independently convert the data into comprehensible units of risk for the public so people know what they are dealing with and can take sensible decisions," he added.

Patrick

Tue Mar 29 2011, 10:03PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Proud Mary wrote ...

Japan may have lost race to save nuclear reactor

Fukushima meltdown fears rise after radioactive core melts through vessel â€“ but 'no danger of Chernobyl-style catastrophe'

Holy Crap!!! This is just getting worse.

At the fukushima diachi, I see on the talking head media, that there are 6 reactors at this site, and that 4 are in excursion. But I only see 4 reactor buildings (1-4) on the precious TV screen. Where are the other two reactor sites?

Proud Mary

Tue Mar 29 2011, 10:17PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Patrick wrote ...

I shan't be at all surprised if one or more of the damaged reactors end up encased in concrete like the Windscale Atomic Pile, still too dangerous to 'decommission' after 50 years.

GluD

Tue Mar 29 2011, 11:10PM

Registered Member #1221 Joined: Wed Jan 09 2008, 06:17PM
Location: Odense, Denmark
Posts: 196

I only see 4 reactor buildings (1-4) on the precious TV screen. Where are the other two reactor sites?

This picture from the wikipedia, seems to show that there is a considerable distance betwen the reactors 1-4 and 5,6.

Patrick

Wed Mar 30 2011, 02:17AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

GluD wrote ...

I only see 4 reactor buildings (1-4) on the precious TV screen. Where are the other two reactor sites?

This picture from the wikipedia, seems to show that there is a considerable distance betwen the reactors 1-4 and 5,6.

I saw that picture before I posted, but failed to realized the caption pointed out 6 under contruction. TY Glud.

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