The operator of the crippled Fukushima Daiichi nuclear power plant says it has finished removing highly radioactive water from underground tunnels linked to the reactor buildings.
More than 10,000 tons of highly contaminated water flowed into the tunnels outside the buildings for reactors No.2 and 3. Experts feared that the water might seep into the sea.
The concern led the plant operator, Tokyo Electric Power Company, to try and block any more tainted water from entering the tunnels.
The firm has been filling the tunnels with cement to pump out contaminated water since November.
It finished draining the No.2 reactor building’s tunnels late last month. The company says it also completed similar work on the tunnels connected to the No.3 reactor building on Thursday.
The firm will continue the work to fill the tunnels with cement until sometime late next month.
The utility initially attempted to freeze radioactive water in sections where the tunnels connect to the reactor buildings. But this did not work.
The government and TEPCO had placed top priority on addressing the highly radioactive water in the tunnels due to a fear that it might badly pollute the sea near the plant. The latest achievement will significantly reduce that risk.
TEPCO announced that they have completed the concreting of the unit 3 seawater piping trench system. Two vertical shafts are being filled currently to complete the last of this project.
Tepco reports that contamination levels in the unit 1 discharge canal has been rising significantly….
*Cesium 137 was at 91,000 bq/liter Beta radiation was at 110,000 bq/liter Both readings taken July 24th.
*Cesium 137 was at 79,000 bq/liter Beta radiation was at 94,000 bq/liter Both readings taken July 22th.
*Cesium 137 was at 28,000 bq/liter Beta radiation was at 36,000 bq/liter Both readings taken July 15th.
*Cesium 137 was at 29,000 bq/liter Beta radiation was at 37,000 bq/liter Both readings taken July 13th.
*Cesium 137 was at 20,000 bq/liter Beta radiation was at 26,000 bq/liter Both readings taken July 10th.
Tepco also admitted that subdrain pit #16 has seen a rise in contamination since May
Why either of these locations are now rising does not yet have a definitive cause. Work to concrete in the sea front trenches at the plant could be pushing contaminated water to take other routes. The freezing in progress of the frozen wall could be having an impact on the migration of contaminated water.
Workers at the Fukushima Daiichi nuclear power plant on Sunday will start the removal of a fuel exchanger inside the Number 3 reactor building. The 20-ton device fell into the fuel pool during the 2011 disaster.
The device has since been a major obstacle for workers at Tokyo Electric Power Company in the start of removal of extremely radioactive rubble left in the storage pool. 566 fuel rods remain inside the spent fuel pool.
Workers cannot directly take part in the process as the site is highly radioactive. The work will require 2 remote-controlled cranes that will lift and remove the device, which is some 14 meters long.
The work poses a challenge as spent fuel may suffer damage if the device falls back into the pool during removal.
Workers accidentally dropped a 400-kilogram device into the pool last August. Though none of the rods suffered damage, removal was postponed for 4 months.
TEPCO has been preparing for the removal by developing equipment tailored to grip the device. Cushions have also been placed on top of the fuel rods.
TEPCO officials say all other work to decommission the plant will be suspended while the removal takes place as a hydrogen explosion in 2011 left the pool without a roof.
Source : NHK http://www3.nhk.or.jp/nhkworld/english/news/20150730_05.html
Tepco handout (pdf), summary translation by Fukushima Diary, Jul 21, 2015 (emphasis added): Tepco announced Fukushima plant area has irregularly sunk since 311… The report reads Reactor 1 turbine building sank by 730 mm [2.40 ft], Reactor 2 by 725 mm, Reactor 3 by 710 mm, Reactor 4 by 712 mm.
IAEA Headquarters (pdf), 2015: We know that the buildings will decay and become less stable… there is the dilemma of 1) gathering more information… and 2) acting earlier and maybe not having enough information to make good decisions.
IAEA Nuclear Energy Series (pdf), 2014: The impact of the salt on the corrosion of structural materials had to be assessed and measures taken accordingly to retain integrity.
Lake Barrett, Tepco adviser (pdf): Reactor building structure has likely been degraded… Explosions Weaken RB Structure… Aftershock May Cause Building Failure… — Issues: … Aftershock Structural Integrity… — Safety Challenges: … Containment Degradation
US National Research Council, 2014: Substantial structural damage occurred… particularly Units 3 and 4… The explosions [were] extremely destructive. The complex structure of the lower part of the reactor buildings is well suited to cause flame acceleration… Ironically, having a strong structure with multiple compartments can greatly enhance the damage… this result, although not intuitive, is now well established.
Kazuhiro Suzuki, IRID managing director (pdf), 2014: Estimation of structural strength decline by sea water inflow; Evaluating device/structural integrity and remaining life…
Sugiura Machine Design Office: We obtained results [using a] flying robot. We already have started to work on plant deterioration investigation with major manufacturer.
p. 94: Assessing structural integrity of RPV/PCV… data on corrosion rate will be collected… to evaluate aseismatic strength, taking into consideration long-term wall thinning by corrosion… stainless steel [components] may already be cracked
p. 95: Overall structural integrity… Building behavior analysis (building damage simulation)… Influence of corrosion [and] high-temperature strength deterioration
p. 98: Structural integrity of PCV structures… Corrosion wall thinning… Estimated thinning of Unit 1 dry well [and] suppression chamber… Generated stress… of the suppression chamber support structures was higher [than allowable]… reinforcement (such as burying the torus chamber with cement materials, etc.) will be studied
p. 99: Structural integrity of RPV pedestal… influences of corrosion by molten fuel debris are not taken into account and further study is needed
Part 6: “One more important point I need to cite is to assure the stability of the site… because of the presence of the ocean water, corrosion could take place… preventative measures against the corrosion need to be taken.“
Part 85-87: “Next is assessing structural integrity of RPV and PCV [and] get qualitative data of corrosion rate. There is sea water injected so corrosion may gradually proceed… To be prepared against future possible earthquakes we have to evaluate whether this is tolerant or not… We must consider corrosion.”
Part 91: “PCV [integrity] is generally alright, but in some parts — for instance the column support of the suppression chamber — it [doesn’t meet standards].”
Part 92: “This is the pedestal of RPV… The molten debris may be causing corrosion.”
Source:
Status of R&D Projects Related to Debris Fuel removal
Hey Tepco. You have made steady profits since 2012 when the Taxpayers bailed you out. How about you spend that money and DO something about your 3 melting reactors? Or give it to the hundreds of thousands of people whos lives you have totally destroyed. No. That would be the proper thing to do. Can’t have that.
Tepco is making steady profits since 2012 while still receiving money from the Japanese Government, shouldered by the Japanese Taxpayers:
Japan approves increase in Fukushima compensation to $57 billion
TOKYO (Reuters) – Japan on Tuesday approved an increase in compensation payments for the Fukushima crisis to 7.07 trillion yen ($57.18 billion), as tens of thousands of evacuees remain in temporary housing more than four years after the disaster.
Tokyo Electric Power Co (Tepco), the operator of the wrecked Fukushima Daiichi nuclear station, will receive 950 billion yen more in public funds on top of the 6.125 trillion agreed earlier, the utility and the government said.
Tepco’s Quarterly Profit Triples as Fuel Prices Plunge
Tokyo Electric Power Co., operator of the wrecked Fukushima Dai-Ichi nuclear plant, said first-quarter operating profit tripled as a drop in fuel prices helped cut costs.
Tepco, as Japan’s biggest utility is known, posted an operating profit of 228.3 billion yen ($1.85 billion) for the three months ended June 30, compared with 70.7 billion yen a year ago, the company said in a statement Wednesday.
The company benefited from a more than 45 percent plunge in liquefied natural gas prices after crude oil fell to a record low. More than a third of Tepco’s power generation capacity comes from LNG, compared with 14 percent from oil and 8 percent from coal.
Factoring in the impact of a weaker yen, the plunge in oil prices alone boosted current profit by 276 billion yen, Tepco said.
“With the drop in the price of crude and a minimization of costs, the operating profit is in the black for the second year in a row,” the company said in the statement.
Fuel Spending
Tepco spent 35 percent less on LNG purchases in the first quarter, while consumption of the fuel fell by 5 percent. The company’s spending on crude oil rose by 7.5 percent, while its use was up 25 percent, the company said.
The utility’s purchases of coal rose 4.9 percent to 1.75 million metric tons, resulting in a 3.9 percent increase in spending on the fuel.
Indonesia was Tepco’s largest crude supplier last year, while Australia was the top coal provider.
Total sales dipped 1.1 percent to 1.55 trillion yen as the company generated 6 percent less capacity in the quarter.
Japan’s power consumption dropped 1.8 percent in the quarter from a year earlier, the fifth straight quarterly decline, to 189 terawatt hours, according to industry figures. That’s the lowest quarterly use since 2000.
With Tepco struggling to win approval to restart its nuclear reactors, the drop in fuel costs provides relief.
In June, the price of LNG imported into Japan dropped to $7.60 per million British thermal units, the lowest level in two years. Power utilities with a high ratio of LNG will see an increase in profits, Syusaku Nishikawa, an analyst at Daiwa Securities Co., said by e-mail.
Tepco’s first-quarter net income was 203.3 billion yen, compared with a net loss of 173 billion yen a year ago. The company’s net income is influenced by costs related to the payout to those affected by the Fukushima nuclear accident more than four years ago.
According to Tepco, they started removing the main part of cover of Reactor 1 on 7/28/2015.
They announced that there was no significant change in dust monitoring data and radiation monitoring post readings.
The former Fukushima worker “Happy11311″ commented on Twitter that the high level of contamination might be retained on the ground floor with rain after they take the cover away.
Tepco on Tuesday began dismantling the temporary shroud covering the wrecked reactor 1 building at the Fukushima No 1 nuclear plant.
Tokyo Electric Power Co. installed the cover in October 2011 to keep radioactive materials from dispersing.
Workers used a crane Tuesday to remove one of the six panels that form the shroud’s roof. Each panel is about 7 meters wide and about 42 meters long.
As the panel came off, the upper part of the reactor building could be seen for the first time since December, when part of the cover was temporarily removed. The building’s exterior was shattered in a hydrogen explosion in March 2011, in the first few days of the crisis.
Tepco plans to complete removing the shroud in fiscal 2016 and to clear debris and install equipment for the sensitive process of removing the 392 spent fuel assemblies currently lying in the building’s storage pool. That procedure is expected to begin in fiscal 2020.
Takao Kikori, a senior nuclear safety official in the Fukushima Prefectural Government, called for care to be taken in the dismantling work to ensure the safety of local people.
The utility plans to remove the second panel in early August or later and complete the removal of all six panels by the end of this year. Later it will remove the side panels and install windbreaker sheets ahead of clearing the debris.
The cover was installed as an emergency measure to keep radioactive dust from scattering. Tepco initially planned to dismantle it in fiscal 2013 or 2014 but was forced to delay the work to take additional dust control and other measures.
The operator of the Fukushima Daiichi nuclear plant says the equipment to build an underground ice wall has stopped working due to power failure.
Tokyo Electric Power Company has been conducting trials to create a barrier of frozen soil around the reactor buildings that will keep groundwater from seeping into them.
An alarm was set off on Tuesday morning signaling trouble with a power panel at the plant. Workers then found white smoke rising from a power cable.
Officials at TEPCO also found that part of a system to send nitrogen into the containment vessels of 3 reactors had stopped working.
The equipment has been building the subsoil ice wall by pumping liquid coolant of minus 30 degrees Celsius into pipes installed in the ground around the reactor buildings.
The officials say they do not know when they can restart the equipment. But they say the ice wall will not melt for several days, even without coolant running from the equipment.
The operator of the damaged Fukushima Daiichi nuclear plant has resumed building an underground ice wall after a brief equipment failure.
Tokyo Electric Power Company has been conducting trials to create a barrier of frozen soil around the reactor buildings to keep groundwater from seeping into them.
On Tuesday morning, workers responding to an alarm found smoke rising from a power cable.
They confirmed that all the equipment to build the ice wall had stopped working due to a power failure.
The staff found no problems with the equipment and resumed work in the afternoon using another power system.
The power failure also partially stopped a system that sends nitrogen into the containment vessels of 3 reactors. That work has been resumed as well.
TEPCO says the power cable that was emitting smoke had short-circuited.
The utility is investigating what may have triggered the problem.
The interior of the No. 1 reactor building of the Fukushima No. 1 nuclear power plant can be seen from above after a canopy panel was removed on July 28.
OKUMA, Fukushima Prefecture–Tokyo Electric Power Co. on July 28 started removing a canopy covering a damaged reactor building at the Fukushima No. 1 nuclear plant to prepare for the eventual extraction of spent nuclear fuel inside.
Around 7 a.m., workers using a giant crane lifted away the first of six canopy panels, each measuring 40 meters long and 7 meters wide, from the No. 1 reactor building.
The 30-minute removal of the panel left a large hole in the canopy through which steel beams on the damaged upper part of structure could be seen from above. Workers closely monitored radiation levels in the surrounding areas during the removal process.
The utility plans to remove the remaining five panels from next week.
The removal of the canopy will allow TEPCO to clear debris inside the building, possibly in the latter half of fiscal 2016. That process should pave the way for the removal of nuclear fuel rods from the spent fuel pool in the building.
Before removing the canopy panel, the utility sprayed the inside of the reactor building with liquid resin through holes drilled in the cover to prevent radioactive materials from being stirred up during the dismantling work.
TEPCO initially planned to start removing the canopy panels from the No. 1 reactor building in summer 2014, but the schedule was delayed because a large amount of radioactive substances was released into the environment when the utility removed debris from the No. 3 reactor building in August 2013.
Even after the anti-scattering resin was sprayed into the No. 1 reactor building in May, removal of the canopy panel was postponed by a problem inside the building.
SOMA, Fukushima Prefecture–Fishermen in northern Fukushima Prefecture gave Tokyo Electric Power Co. the green light on July 27 to release radioactive groundwater from the crippled Fukushima No. 1 nuclear power plant into the ocean after it undergoes decontamination treatment.
The Soma-Futaba fisheries cooperative association approved TEPCO’s “subdrain plan” at a board member meeting after earlier approval by the Iwaki fisheries union, which brings together fishermen operating on the southern Fukushima coast, to back the plant operator’s plan.
After the decisions by the two fisheries unions, the Fukushima Prefectural Federation of Fisheries Cooperative Associations is expected to formally approve the subdrain plan in mid-August at the earliest.
To deal with the accumulation of contaminated groundwater at the plant, TEPCO and the central government implemented from May last year a “groundwater bypass” that intercepts clean groundwater before it flows into contaminated reactor buildings and reroutes it safely around the facility into the ocean.
Under the subdrain plan, the utility will pump 500 tons of water from 41 subdrain wells around the premises of the plant’s four crippled reactors each day. It expects that the amount of groundwater flowing into the reactor buildings will be drastically reduced, and the amount of contaminated water generated at the plant will be halved from the current levels.
The water will be released into the sea after it undergoes decontamination treatment to reduce cesium levels to below 1 becquerel and beta ray-emitting radioactive materials to less than 3 becquerels.
Because the decontamination equipment cannot remove tritium, water contaminated with the radioactive isotope that emits 1,500 becquerels or more of radiation will not be released into the sea.
TEPCO has sought the fisheries cooperatives’ approval of the subdrain plan.
But TEPCO’s delay in disclosing the flow of radioactive water into the ocean whenever it rained–which came to light in February–hampered negotiations with the fisheries unions, which felt the incident undermined their confidence in the utility.
At the meeting of the board members of the Soma-Futaba fisheries union, TEPCO officials explained that the subdrain plan was essential in reducing the flow of contaminated water into the ocean, according to Hiroyuki Sato, the union president.
The members who had remained strongly opposed eventually recognized the need for the subdrain plan and agreed to approve it, Sato said.
Based on requests from the two local fisheries cooperatives, the prefectural federation of fisheries unions will demand that TEPCO and the central government conduct periodic checks on waters emitted from the subdrain program.
The prefectural union will also request that a third-party watchdog monitor the process to prevent contaminated water from flowing into the ocean.
It will also request that TEPCO and the government to continue to provide compensation to local fishermen, while taking effective measures when the subdrain project causes harmful rumors about their products.
Toru Ogawa, a 64-year-old nuclear research expert, has been entrusted with probably the most challenging task facing Japan — leading the decommissioning process at the Fukushima No. 1 nuclear plant.
This April, Ogawa, a professor at Nagaoka University of Technology in Niigata Prefecture, was installed as the first chief in the Collaborative Laboratories for Advanced Decommissioning Science, a government-funded research center supporting the decommissioning.
“Our research and development must be flexible based on our analysis of the (March 2011) accident and information collected by robotic probes (in the reactor buildings),” Ogawa said during a recent interview.
The center started out with a workforce of 80 within the Japan Atomic Energy Agency based in Tokai, Ibaraki Prefecture, as a research base for decommissioning the plant, which is plagued by increasing amounts of contaminated water.
Looking back on the disaster, which was triggered by the powerful Great East Japan Earthquake and tsunami in March 2011, Ogawa said, “The government and the agency should have envisioned the worst-case scenario, in which all multiple layers of defense are destroyed.”
When the plant lost nearly all of its power sources and consequently the ability to cool the reactors and spent fuel pools, units 1, 2 and 3 suffered core meltdowns, while hydrogen explosions damaged the buildings housing reactors 1, 3 and 4.
“We will certainly need technological support from abroad,” Ogawa said.
He added that “we can’t carry out the decommissioning task” unless the center receives support and expertise from the United States, which experienced a meltdown at its Three Mile Island power plant in 1979, and other countries that have disposed of military nuclear waste.
Ogawa said he wants to increase the total workforce at the center to some 150 by inviting around 10 Japanese and foreign experts each year.
The center will be moved closer to Fukushima No. 1 during fiscal 2016, which begins next April 1.
A native of Yokohama, Ogawa studied nuclear engineering at Tohoku University in Sendai.
The focus of his research was on high-temperature gas reactors — the next generation reactor known to have a lower risk of core meltdowns, rather than commercial light-water reactors like the ones at Fukushima No. 1.
In researching what will be needed to complete the decommissioning project, which will take several decades, he is currently assessing the state of the melted fuel in reactors 1, 2 and 3, putting together a puzzle with small scraps of information obtained by robotic probes in the reactor buildings.
On 7/25/2015, the former Fukushima worker “Happy11311″ posted on Twitter that Tepco is going to start removing the largest debris from SFP 3 (Spent Fuel Pool of Reactor 3) on 2nd August. “Joint communications” published the news followed by other mass media but Tepco has made no official announcement on their website.
Joint communications reported that the debris to be removed weighs 20 t, but “Happy11311″ commented on Twitter that it is the 35 t of fuel handling machine. He added this is one of the most risky processes in decommissioning of Fukushima plant as fuel removal from SFP 4 (Spent Fuel Pool of Reactor 4).
More than four years after the plant was hit by a massive earthquake and tsunami, Fukushima Daiichi’s operator Tokyo Electric Power said it would start work on the critical task this week using a specially designed crane.
“The debris will be pulled out using two cranes, but we had to create a specially designed hook with a unique shape for it to securely hold on to the object,” a Tepco spokesman told Japan Real Time on Monday.
The object is what remains of a fuel handling machine originally located above the surface of the water. The debris is preventing Tepco from removing the spent fuel rods to a safer location. It is the largest object requiring removal inside the power plant’s reactor No. 3, according to the company.
The removal will be conducted at the slowest possible speed to ensure safety. The pool’s water level, as well as any signs of a jump in radiation levels, will be monitored closely with multiple cameras during the procedure. The debris must be lifted so that it won’t swing or cause damage to the spent fuel pool’s gates.
While it is unlikely that any water from the pool will leak even if the object comes into contact with the gate, Tepco said it will be ready to add water in case of a drawdown. Reduced water levels or exposure to air could cause the radioactive fuel rods to heat up.
All other procedures at Fukushima Daiichi will be halted while the debris is being removed, according to the company.
It’s impossible to even slightly decontaminate the area damaged by the Fukushima nuclear disaster because of the mountains and dense forests in that region, says Mycle Schneider, independent analyst on energy and nuclear policy.
Tokyo’s preparing to declare some parts of the evacuation zone around the crippled Fukushima nuclear plant, a safe place to live. However environmentalists warn many areas still show radiation levels 20 times the globally accepted limit.
RT: Do you think people will take the advice of the Japanese government and move back to the area? Do you personally think its safe?
Mycle Schneider: A number of opinion polls, surveys have shown that the percentage that is decided to go back might be around a fifth of all people evacuated, many people are still undecided and about half decided not to go back. People have to imagine – besides the radiation situation – what are they going back to. We should not forget that many of the homes in Japan are made of wood and they are basically in extremely bad shape and would have to be completely redone. There is not much to go back to and on top of it there is the radiation issue. There is also the issue of going back to their homes but what about their neighbors, what about collectivity, what about the services? So there are all kinds of other social issues besides the pure health issue.
RT: What could be the potential consequences of returning to the area? How long does it take to actually clean the area from nuclear contamination?
MS: I don’t think it is possible to clean up in the real sense of the word, meaning that you take away the added radioactivity that has been contaminating the soil, the roofs, everything. It’s impossible. So what you can do is you can reduce the radioactive contamination in some of the areas. You can take off soil; you can decontaminate what has been done by water sprayed. But keep in mind that 80 percent of Japan is mountains and in this area as well there is a lot of mountains, there is a lot of dense forest, there is absolutely no way even to slightly decontaminate that region. So you will not have a stable situation of contamination but it will move all the time and a new radiation will wash down from the mountains and forests into the other lands.
RT: Why do you think Tokyo wants people back in the area?
MS: It’s not very complicated. According to a partial estimate – there is no total public estimate of the cost of Fukushima disaster so far – but a partial estimate says it’s about $100 billion. Sixty percent of that has been spent for compensation measures. So compensating people for their loss of land and jobs is very expensive to the government and since the government has bailed out the company that ran the Fukushima reactors it’s basically now the government that is liable. So it’s a matter of reducing the overall cost of the disaster.
RT: Are there other cases where people have returned to the region of a nuclear disaster?
MS: Not really. Everybody knows about the Chernobyl disaster and the 30-kilometer exclusion zone remains. There are people that have returned to that zone, but without authorization. So it wasn’t a government measure of massively allowing people to go back. There are other areas that have been touched by nuclear disasters, but there is nothing really comparable of a densely populated area like in Japan.
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