When does Tepco trot out their version of an Idiot Defense ?
http://www.japantimes.co.jp/news/2013/05/21/reference/fukushima-no-1-cant-keep-its-head-above-tainted-water/#.UZpXQ2fYGTc
http://www.japantimes.co.jp/news/2013/05/21/reference/fukushima-no-1-cant-keep-its-head-above-tainted-water/#.UZpXQ2fYGTc
CONTAMINATED WATER IN FUKUSHIMA
Fukushima No. 1 can’t keep its head above tainted water
BY REIJI YOSHIDA
STAFF WRITER
More than two years into the triple-meltdown crisis at the Fukushima No. 1 power plant, workers continue to wage a desperate battle to keep the stricken reactors cool while trying to contain the 400 tons of radioactive water produced by the process each day.
Tokyo Electric Power Co. must decommission the three reactors, but the water is thwarting the effort. The decommissioning, if it ever starts, will take decades.
Here are some questions and answers on the encroaching problem and its implications for public health and the environment:
Why is radioactive water accumulating and how much is there?
As of May 7, Tepco had routed 290,000 tons of radioactive water into some 940 huge tanks at the complex, but 94,500 tons remain inside the basement floors of the reactor buildings and other facilities.
Tepco must perpetually pour water over the melted cores of reactors 1, 2, and 3 via makeshift systems to prevent the fuel from melting and burning again.
But the cores’ containment vessels were damaged by the meltdowns, allowing the highly radioactive coolant water to leak and flow into the basements. The dangerous radiation levels have prevented workers from getting close enough to fully assess the damage, let alone start the decommissioning process.
Compounding the problem is some 400 tons of groundwater that is also entering the basements of the tsunami- and explosion-damaged buildings, mixing with the leaking coolant water.
Tepco has been operating a water-recycling system to drain the basements that is supposed to extract cesium before recirculating the water back to the reactors. But the added inflow of the groundwater is exacerbating the threat.
In response, all Tepco has been able to do is build more storage tanks.
What problems will the water eventually pose?
Tepco says there is a limit to how many tanks the complex can accommodate before the site runs out of storage space.
Tepco said it can boost storage capacity from 430,000 tons from this year to 700,000 tons by mid-2015 by clearing a forest and other space in the compound. The move is expected to buy them about three years’ time.
Tepco is proposing some of the water be dumped into the sea after processing it to remove most, but not all, radioactive isotopes. Local fishermen strongly oppose the plan as it will taint the image of their produce.
Previous discharges into the Pacific have effectively contaminated the sea. Failure to store it means it will probably flood the whole compound and end up in the ocean anyway.
Neither Tepco nor government experts have come up with any other viable solutions.
Will the processed water pose health or environmental risks?
According to Tepco, the processed water could theoretically be safe, but fishermen and consumers disagree.
Tepco has been using an advanced liquid processing system made by Toshiba Corp. to decontaminate the coolant water.
ALPS can bring the density of 62 main radioactive substances below detectable levels, including strontium and plutonium.
Tritium is the exception, however. Tepco says the tritium level in the contaminated water is between 1 million and 5 million becquerels per liter. The legal limit is 60,000.
Tepco thus wants to dilute the water to bring the tritium density below the legal limit by dumping it into the sea. It has promised not to dump any without gaining the nod of local fishermen first.
Tritium, a common hazard at nuclear plants, can increase the risk of cancer if ingested and has a half life of 12.3 years. It is about 1,000th as radioactive as cesium-134 and -137.
Are there other concerns over water-related facilities?
Tepco revealed on April 5 that radioactive water stored in makeshift cisterns with coamings and surface covers were leaking into the soil.
This forced the utility to stop using the reservoirs, which were basically lined trenches with lids, and pump some 24,000 tons of tainted water out of them and into aboveground tanks.
The transfer is expected to be finished later this month.
Experts also are worried about the integrity of the 940 aboveground tanks built as of April 1, since 280 of them are considered “temporary” because they can only be used for up to five years. These are made of steel plates bolted together with waterproof packing to seal the seams, unlike welded steel tanks that offer a longer-term solution.
Tepco will need to start repairing or replacing the temporary tanks in spring 2016.
Tepco has dug 12 wells to intercept groundwater before it seeps into the reactor building basements. Will this work?
Yes, but only to a certain extent.
The wells were dug on the mountainside above the damaged buildings. Tepco plans to pump up as much groundwater as possible to keep it from entering the basements as it heads to the sea.
But Tepco estimates the wells can only pump up 100 of the 400 tons leaking into the buildings every day.
Tepco was going to release the well water into the sea because its radioactivity is much lower than the safety standards for drinking water set by the World Health Organization.
It suspended the plan on May 13 after the local fisheries association vetoed the idea, fearing any further discharge would only worsen the already marred image of local seafood.
M5.9 caused further overflow of contaminated water, Tepco “The tank was full since yesterday”
Posted by Mochizuki on May 18th, 2013
At 14:48 5/18/2013, M5.9 hit Fukushima offshore. (cf, M5.9 hit Fukushima offshore at 14:48 5/18/2013 (JST) [URL]) According to Tepco, this quake caused another overflow of contaminated water. On 5/17/2013, Tepco had 27.5 m3 of contaminated water overflow from the tank of reactor5&6. (cf, 27.5 m3 of contaminated water overflowed from tank of reactor5&6, “Forgot [...]
Remote-control heavy equipment leaked flammable oil on debris removal of reactor3, Tepco “Far enough from SFP”
Posted by Mochizuki on May 18th, 2013
According to Tepco, a remote-control heavy equipment leaked oil. Around 14:08 5/18/2013 (Before M5.9), a Tepco employee in the operating room found the remote-control heavy equipment leaking oil. The heavy equipment was removing the debris from the top of the reactor3 building. At 14:33, they reported it to Tomioka fire station. Tepco is assuming the [...]
27.5 m3 of contaminated water overflowed from tank of reactor5&6, “Forgot to switch the tanks”
Posted by Mochizuki on May 17th, 2013 · 1 Comment
According to Tepco, they had 27.5 m3 of contaminated water overflowed from the tank of reactor5 and 6.
Tepco states Cs-137 and total β were lower than the detectable levels, and the water didn’t reach the Pacific ocean because the tank is 100m from the sea, which is supposed to be far enough for some reason. Cs-134 level and other nuclide levels are not reported.
They forgot to switch the tanks to cause overflow, they report.
The press release is below,
Reactor1 temperature rised after nitrogen gas injection
Posted by Mochizuki on May 17th, 2013 · No Comments
Since 5/14/2013, Fukushima Diary has been reporting the unusual increase of temperature in reactor1.
(cf, Reactor1 reaching 49℃, increased by 3℃ within 24 hours [URL])
On 5/17/2013, Tepco reported the temperature increased just after they injected nitrogen gas into PCV.
(cf, Tepco to restart nitrogen gas injection into reactor1 [URL 2])
However last year, reactor1 temperature decreased when they injected nitrogen gas, which is the opposite reaction from now.
According to the minutes of mid/long term Fukushima measures meeting held on 10/22/2012, Tepco is aware of this strange connection between nitrogen gas injection and the temperature but doesn’t know how it affects.
(cf, Tepco reported they don’t know why nitrogen injection decreases the temperature of reactor1 [URL 3])
Radiation level jumped over 7 times much around multiple nuclide removing system 6 weeks after test operation
Posted by Mochizuki on May 17th, 2013 · No Comments
In order to purify the increasing contaminated water, Tepco is planning to install ALPS (Advanced Liquid Processing System).
The system is to remove 62 sorts of multiple radionuclides including Sr-90.
They started the test operation on 3/30/2013.
6 weeks have passed and the radiation level is significantly increasing around the facility already.
According to Tepco, the atmospheric dose was lower than 1μSv/h before the performance test.
On 5/14/2013, they measured 20 ~ 70 μSv/h beside the equipment.
On 5/16/2013, they measured 20 μSv/h on the North East side of the area.
Tepco states it doesn’t affect the works around the facility.
Related article..[Checkmate] Atmospheric dose in plant area jumps up by 6.4mSv/y for direct radiation from contaminated water [URL 2]
[Mysterious reactor2] Tepco couldn’t purge hydrogen gas from suppression chamber
Posted by Mochizuki on May 17th, 2013 · No Comments
Tepco injected nitrogen gas into the suppression chamber of reactor2 from 5/14 to 5/17/2013.
(cf, Tepco to start nitrogen gas injection into reactor2 for the first time, “Not knowing the hydrogen gas concentration” [URL])
(cf, [Reactor2] Air pressure of Suppression Chamber was lower than Dry Well, “can’t purge hydrogen gas” [URL])
In order to purge hydrogen gas from suppression chamber, which may cause hydrogen gas explosion, Tepco has been injecting nitrogen gas into reactor1 however this is their first time to attempt injecting nitrogen gas into reactor2 suppression chamber.
Because they don’t even know the hydrogen gas concentration in suppression chamber of reactor2, Tepco tried to purge it to dry well.
However, they didn’t detect any change in hydrogen gas concentration after nitrogen gas injection. Now even the presence of hydrogen gas in suppression chamber is questionable.
By this moment of 5/17/2013, still it’s a mystery how the inside of reactor2 is.
In order to purify the increasing contaminated water, Tepco is planning to install ALPS (Advanced Liquid Processing System).
The system is to remove 62 sorts of multiple radionuclides including Sr-90.
They started the test operation on 3/30/2013.
6 weeks have passed and the radiation level is significantly increasing around the facility already.
According to Tepco, the atmospheric dose was lower than 1μSv/h before the performance test.
On 5/14/2013, they measured 20 ~ 70 μSv/h beside the equipment.
On 5/16/2013, they measured 20 μSv/h on the North East side of the area.
Tepco states it doesn’t affect the works around the facility.
Related article..[Checkmate] Atmospheric dose in plant area jumps up by 6.4mSv/y for direct radiation from contaminated water [URL 2]
[Mysterious reactor2] Tepco couldn’t purge hydrogen gas from suppression chamber
Posted by Mochizuki on May 17th, 2013 · No Comments
Tepco injected nitrogen gas into the suppression chamber of reactor2 from 5/14 to 5/17/2013.
(cf, Tepco to start nitrogen gas injection into reactor2 for the first time, “Not knowing the hydrogen gas concentration” [URL])
(cf, [Reactor2] Air pressure of Suppression Chamber was lower than Dry Well, “can’t purge hydrogen gas” [URL])
In order to purge hydrogen gas from suppression chamber, which may cause hydrogen gas explosion, Tepco has been injecting nitrogen gas into reactor1 however this is their first time to attempt injecting nitrogen gas into reactor2 suppression chamber.
Because they don’t even know the hydrogen gas concentration in suppression chamber of reactor2, Tepco tried to purge it to dry well.
However, they didn’t detect any change in hydrogen gas concentration after nitrogen gas injection. Now even the presence of hydrogen gas in suppression chamber is questionable.
By this moment of 5/17/2013, still it’s a mystery how the inside of reactor2 is.
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