Sunday, March 20, 2011
THE DISASTER CONTINUES Japan Atomic Emergency Bulletin #4
[RUSH TRANSCRIPT, MAY CONTAIN SPELLING ERRORS]
[Early March 21st, 2011 in North America]
Now that the bombing of Libya has started, we can all forget about the on-going nuclear disaster. People are getting bored with news out of Japan. More than half the media is reporting the damaged Fukushima Dai-ichi Reactor is under control, or the authorities are making "good progress".
Is it all over?
Time to move along folks, nothing to see here. Our attention span is only about a week long anyway.
Except one of the world's worst nuclear accidents is far from over.
This is Radio Ecoshock. I'm Alex Smith with Japan Atomic Emergency Bulletin #4, dated March 21st. We will explore information coming in, reactor by reactor. The story changes by the hour, and much depends on who you believe.
We can say several Fukushima Reactors, and their spent fuel pools are still out of operator control, some are still emitting dangerous radiation, and a more serious accident could still occur at any time.
Quickly, there are six nuclear reactors set side-by-side at the Fukushima site, on the Eastern coast of Japan 220 kilimeters, or 136 miles, north of Tokyo.
Three of them, units four to six, were shut down for periodic maintenance, which happens often for such old reactors. As we'll see, even shut down, Japanese reactors pose a serious danger.
Reactors one to three were operating at the time the earthquake struck on March 11th. Rods to quell the nuclear reaction were dropped automatically, but within an hour a tsunami knocked out all power to all six reactors at the Fukushima site. Various out-buildings and pumps were also washed away or damaged.
What is the situation, as March Monday March 21st begins in North America?
The most reliable data seems to be published in a graph from the Japan Atomic Industrial Forum, and republished in part by the Guardian newspaper in the UK. The date is March 20th.
RADIATION LEVELS AT THE PLANT
First of all, the radiation level at The West Gate of the plant was 269 microsiverts, while radiation north of the Service Building was 3,054 microsiverts. In American measurements, 1 Sivert is about 100 rem. A chest X-ray is anywhere from 6 to 18 microsiverts. The lowest clearly carcinogenic level is 100 microsiverts per year. So at over 3,000 microsiverts, parts of the Fukushima plant are extremely dangerously radioactive.
Let's look at each reactor.
REACTORS #5 AND #6 SPENT FUEL POOLS UNDER CONTROL - GOOD NEWS
Reactors #5 and 6 were out of service at the time of the earthquake. Although their spent fuel pools heated up after the tsunami, power was restored to these reactors using backup generators several days ago. Neither of these reactors had their outer shells destroyed by ane explosion. A power company official reported the roofs were intentionally punctured in both #5 and #6 out buildings to prevent hydrogen gas build-up.
Tepco now says the spent fuel pools at #5 and #6 are below the boiling point, and under control, with water being pumped in.
This is the good news emphasized in many recent news reports.
Tepco now says that measurements from drone overflights show temperatures in all the spent fuel cooling ponds are below 100 degrees C. - that is, they have stopped boiling off, following days of dumping tons of sea water on various reactors. Some pools may still be leaking. American authorities announced that some fuel rods were exposed, were seriously damaged, and emitted dangerous radiation.
We'll talk more about that shortly.
According to the March 20th report of the Japan Atomic Industrial Forum (JAIF) the inner reactors of #5 and #6 have kept their intregrity. Tepco is keeping a vent open in the outer containment buildings of both reactors, to avoid a hydrogen explosion.
REACTOR #4 - FUEL PONDS
JAIF reports no problems with the reactor vessel of #4, which was down for maintenance. However, in a procedure apparently unique to Japan, all the hot fuel rods from the reactor had been switched out to the spent fuel ponds, which have no solid containment system.
The fact that the outer building was not blown off, made it more difficult to see what was happening in the spent fuel pool. While some experts say that pool boiled down, and could not be replenished by dropping water from above, on March 20th JAIF reports only "water level low, sea water spray continue, hydrogen from the pool exposed."
Further down in the same chart, JAIF says the operator Tepco has been unable to measure water temperature in the #4 reactor spent fuel pools since March 14th, a week ago.
The situation there remains dangerous. There is no power to the building, the built-in pool cooling pumps are no operational, Tepco is trying to spray in sea water through a hole in the side of the outer containment building.
The fuel rods within the pool are highly radioactive, since they were taken from a live reactors. This remains a dangerous situation.
REACTOR #3 - THE CURRENT DANGER
Over the weekend, the situation at reactor #3 flared up again. JAIF reports, quote, "the pressure at the containment level of Unit 3 increased this morning (20th). The pressure became stable at higher level after this increase."
At first operators suggested they would have to release more radioactive steam from reactor 3, to lower pressure. But currently they are holding at a higher pressure, saying they may have to vent radiation later. British newspaper The Independent reported late Sunday that work on reactor #3 was suspended, due to fears of explosive pressure within the reactor.
If steam is vented from reactor number 3, it would contain iodine 131, cesium 137 and other radioactive by-products.
Within the reactor, JAIF says the core and fuel integrity have been damaged, a situation they picture as red, the most serious. The reactor vessel integrity is not known. There have been reports of cracks, from other sources.
There is no power to cool the reactor core. Nuclear fuel rods have been exposed, but JAIF says sea water is being pumped into the core. According to JAIF, the water level in the spent fuel pond of Reactor #3 is low, while being sprayed for long periods with sea water.
Tepco announced on Sunday March 20th that it may take several more days to connect power to reactors #3 and #4.
The core and fuel of reactor #2 have been damaged, a situation red, according to JAIF. Damage is suspected to the containment vessel. Despite news reports of electric power arriving at the Reactor #2, even to "a switchboard", there is no power running cooling of the reactor core or the spent fuel ponds, as of March 20th.
Reactor fuel has been exposed, with unknown damage. Sea water is being pumped to the core continuously. JAIF says the pressure level of Reactor #2 is "unknown." That is
serious, but at least the pressure in the outer containment vessel is listed as low, and containment venting has been temporarily stopped.
Even with power, no one knows whether the instrumentation, or the cooling pumps will work in this reactor. It is still possible that just turning on the electricity will spark one or multiple fires, especially now that the entire building has been nearly flooded by salt sea water for several days.
Water injection to the containment vessel is being considered. Sea water injection to the spent fuel pool of reactor #2 just started Sunday, Monday in Japan.
Both the core and the nuclear fuel rods of reactor #1 are listed as damaged (red) by JAIF. The reactor pressure vessel integrity is "unknown". There is no core cooling by the built-in pumps, nor any working electrical power to the building, except to some outer connections. Previously, the power lines to reactor #1 came through reactor #2.
The building was severely damaged, in all three events: the earthquake, the tsunami, and the following hydrogen explosion which blew off the roof and other parts.
Fuel was exposed in reactor #1, according to JAIF. The reactor pressure level is supposed to be stable, but the containment vessel pressure is "unknown". Containment venting has been "temporarily stopped."
Sea water is being pumped into the core. As of March 20th, Tepco is still considering whether to inject sea water into the spent fuel pool of reactor #1.
As with reactor #2, and this is a caution raised by the International Atomic Energy Agency, the IAEA, no one knows if the pumps or other functions of the reactor will function, even if and when power is restored in a few days.
That is the latest situation, always changing, at the Fukushima reactors as of very early Monday March 21st.
NHK World Japanese television is reporting "a high level of radiation observed across the plant property". Large chucks of radioactive debris has prevented some of the fire trucks from reaching the best positions for spraying the spent fuel ponds.
On Monday, the Japanese Defense force brought in a tank with a bull-dozer blade to clear some areas.
In the same report, NHK World says the operator Tepco has given the highest priority to restoring power to reactor #2. Because the outer building is still intact, they had trouble getting water to the reactor from outside. The big concern there is the heating fuel rods inside the reactor.
There is still no power hooked up to the central control room of reactor #2, and so the company has few measurements of what is going on inside this reactor. That makes it difficult to know what to do, according to NHK TV experts.
THE REST OF THE NEWS ABOUT THIS ACCIDENT
This is Radio Ecoshock. I'm Alex Smith. Now I'm going to quickly run down some of the other news about this accident at Fukushima Dai-ichi reactor in Japan.
As you no doubt heard, low levels of radioactive iodine were detected in Tokyo tap water. This was above safe limits, but the government assured about 30 million people in the region that there was no health concern. Bottled water has sold out in Tokyo, and many people have already left the city.
Radioactivity has also been found in vegetables and milk in two prefectures.
An investigation by the Wall Street Journal shows the Fukushima Dai-ichi plant had more serious incidents than any other large nuclear facility in Japan, even before the Earthquake. It was aging, and the original design was poor.
Also, Japanese power companies handle reactor fuel differently than their American counterparts. When it comes time to service a reactor, U.S. nuclear operators move only some of the still active fuel rods to the spent fuel pool, while keeping most within the much more protected reactor vessel. At Fukushima Dai-ichi reactor #4, as with most Japanese reactors, all the hot rods were placed in the cooling pools, which have no safe outer containment, and depend completely on water pumping to stop a nuclear reaction.
The less safe practice contributed to the serious fears about overheating in the spent fuel pools of reactors #5 and #6, but especially reactor #4. It is called "full core discharge", and that practice may have to be reexamined in light of this accident.
On Sunday, Gregory Jaczko, chairman of the U.S. Nuclear Regulatory Commission says radiation levels athe power plant are still high, but may be coming down. He said, quote,
"It's difficult to obtain accurate information." adding, "It's premature to make any assessment about the most severely affected reactors."
The Los Angeles Time reported Sunday night, quote: " The reactor containment vessel at No. 2 may be cracked and venting some radioactive gases into the environment. Reactor No. 3 is the only reactor at the site that contains plutonium in the fuel rods and its escape would be extremely dangerous because it is carcinogenic in even minute doses."
That article also concludes that at least the top halves of the fuel rods of reactors 1 through 3 were exposed for several days. Damage to the fuel rods may make them harder to cool, even if the reactor pumps can be made to work again.
Keep in mind, that the chlorine in sea water, now being pumped into reactors and spent fuel ponds, is very corrosive to the stainless steel pipes running all through these reactors.
That may mean further damage has occured.
Both the New York Times and the Wall Street Journal are reporting the Tokyo Electric Power Company hesitated to use sea water, a delay that may have increased both damage to the reactors and fuel, and an increase in radiation released. The private company was reportedly concerned that once sea water was used, the big investment in the plant, and all the much-needed power it produced, would all be lost.
On March 20th, Japanese authorities acknowledged that the Fukushima Dai-ichi plant would never be reopened. If a further nuclear melt-down can be averted, some of the most extreme radioactive materials might be removed, and then the site may be encased in cement, as Chernobyl was. The plant is definitely finished, but just how it can be contained is still undecided.
Tepco announced at least two dozen members of the Japanese Self-Defence Force have been exposed to unsafe levels of radiation. More than 20 workers have been injured. One crane opertor was declared dead at the site early in the accident, and two workers remain missing. We have heard little about the 50 workers who stayed inside the plant in the early days, and no reports on the health of firemen and helecopter pilots working at the site.
Meanwhile, the head of the International Atomic Energy Agency, Yukiya Amano, said on leaving Japan, quote: "I hope that safety, stability will be recovered as soon as possible... but I still don't think it is time to say that I think they are going in a good direction or not."
I believe that.
Thank you for keeping your ears and eyes on this continuing serious situation - a multiple reactor accident in Japan, one of the world's most advanced nuclear nations.
I'm Alex Smith. This is Radio Ecoshock.
Keep tuned to our podcast. Subscribe at our main page, ecoshock.org
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Posted by Alex Smith at 11:43 PM
Labels: accident, environment, Japan, nuclear, nuclear power, radiation, reactors
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