TV: Only ‘some’ of Fukushima melted fuel is now solid — Nuclear Expert: Molten core ‘re-melts’, even with enough cooling water — Japan Engineer: “The Fukushima accident was the first of its kind” (VIDEO) http://enenews.com/tv-only-fukushimas-melted-fuel-solid-nuclear-expert-molten-core-will-melt-enough-cooling-water-japan-engineer-fukushima-accident-first-kind-video?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+ENENews+%28Energy+News%29
NHK, Jan 27, 2015 (emphasis added): Groundwater entering the facility becomes tainted when it mixes with melted fuel inside the reactor containers. Tepco engineers believe some of the fuel has cooled down and turned into solid debris. But they don’t know the exact situation, so they’re hoping to take a look inside… Scientists have figured out a way of using muons to help them see substances hidden from views — like magma… When particles hit a high-density object like magma, they lose energy or are absorbed… it’s like an x-ray. Researchers are hoping to use the technique to get a better idea of what’s inside the reactors… Engineers will… try and determine the state of the melted fuel… Engineers say knowing what’s inside will help them figure out a way to decommission the plant.
Asahi Shimbun, Jan 24, 2015: [TEPCO] will use cosmic rays… to identify sites with melted fuel… They will first study the No. 1 reactor… by the end of this fiscal year, estimating how much fuel remains in the reactor[and] intend to extract the melted fuel after surrounding it with water… the plant operator will need to repair damaged sections of the containers to prevent water leaks… However… nuclear fuel at the base of the container cannot be seen using the muon technique…
Dr. Ing. Mazzini, Ph.D. Nuclear & Industrial Safety (pdf): Severe Accident Phenomenology…Milestones of Nuclear Safety: 2011 Fukushima Accident (1st for an External Event)
- Ex-Vessel Accident Phenomena:
-> The molten debris falls into the reactor cavity. This produces boiling off of whatever water is there. If sufficient water is present, the core would be cooled and solidify, and would subsequently re-melt.
-> Steam explosions may also occur at this time as the molten fuel falls onto water in the reactor cavity. This can disperse fuel, create radioactive aerosols, and increase the rate of heat transfer to the containment atmosphere.
-> Molten corium attacks the concrete basement, which proceeds to penetrate, and creates a cauldron that releases aerosols and gases [and] containment pressure rises.
DPA, Jan 28 2015: More delays expected in Fukushima nuclear plant clean-up… More delays in treating contaminated water from Japan’s crippled Fukushima nuclear power plant are likely, a senior official of a company involved in the clean-up said Wednesday. “Some schedule(s) would be delayed because the contaminated facility did not operate as planned,” [said] Yoshiki Ogata, director of the global nuclear project department of Mitsubishi… “The situation in the building is not clear,” he told dpa on the sidelines of a nuclear energy conference. Mitsubishi, along with Toshiba and Hitachi, are the three companies helping… Ogata said that the Fukushima accident was the first of its kind so there were a lot of challenges… “So, first stop the underground water from entering and also leakage to the sea…”
Watch the NHK broadcast here
Jan. 29, 2015
Japan’s environment ministry plans to soon start building initial facilities for storing radioactive waste stemming from decontamination work in Fukushima Prefecture, northern Japan.They are part of the intermediate storage complex to be built in a 16-square-kilometer area straddling the towns of Futaba and Okuma.The government earlier planned to start moving the waste to the site by the end of this month. But it canceled the plan due to delays in purchasing land and building facilities.The government now plans to start the transport by March 11th, the 4th anniversary of the earthquake and tsunami that led to the nuclear accident in 2011.
The ministry says construction of 2 initial storage facilities, each 10,000 square kilometers, will start next Tuesday at industrial parks in the intermediate site.The waste is to be kept there until intermediate storage facilities are completed. It remains unclear when their construction will begin, due to lack of progress in purchasing land.Huge amounts of radioactive soil and other waste stemming from decontamination work have been kept in each municipality of the prefecture.
Municipalities are asking the government to provide a concrete schedule for transporting the waste.
January 27, 2015
On 1/27/2015, Tepco announced they measured high density of Strontium-90 from groundwater in the seaside of Reactor 2.
It was 31,000,000 Bq/m3. The sampling point was the boring well, which is the closest to Reactor 2.
This is the highest density measured from this boring well, which is 10% more than the previous highest record.
The sampling date was last December. No Sr-90 data of January has been published.
Source: Fukushima Daiichi
January 28th, 2015
Study: Global consequences from Fukushima-like nuclear disaster; Many nations at risk of ‘great exposure’ — Transport of hot particles to US was especially effective during worst releases after reactor explosions — Radioactivity confined ‘close to surface’ due to seasonal factors
T. Christoudias and Y. Proestos of The Cyprus Institute, J. Lelieveld of Max Planck Institute of Chemistry (Germany), Dec 12, 2014 (emphasis added):
- We estimate the contamination risks from the atmospheric dispersion of radionuclides released by severe nuclear power plant accidents… We present an overview of global risks… [These] risks exhibit seasonal variability, with the highest surface level concentrations of gaseous radionuclides in the Northern Hemisphere during winter [Fukushima crisis began with 10 days left in winter].
- The model setup was evaluated… using emission estimates from… Fukushima
- The risk posed from nuclear power plant accidents is not limited to the national or even regional level, but can assume global dimensions. Many nations may be subjected to great exposure after severe accidents.
- Our model shows increased surface-level concentrations throughout the Northern Hemisphere during the boreal winter months compared to the summer… Not only the expected risk magnitude is higher, but the geographical extent of the high concentrations of transported radionuclides is more pronounced towards the north… Horizontal advection [i.e. transfer] is more efficient in winter due to relatively stronger winds, and the concentrations are highest near the surface [and] surface level concentrations in the summer tend to be more localized in the emission region.
- Our results illustrate that accidents… could have significant trans-boundary consequences. The risk estimate [shows] increased surface level concentrations of gaseous radionuclides in the Northern Hemisphere during winter and a larger geographical extent towards the north and the east… This is related to the relatively shallow boundary layer in winter that confines the emitted radioactivity to the lowest part of the atmosphere close to the surface…It is the view of the authors that it is imperative to assess the risks from the atmospheric dispersion of radioactivity from potential NPP accidents [for] emergency response planning on national and international levels.
JAMSTEC, Univ. of Tokyo, etc.: We show a numerical simulation for the long-range transport from the [Fukushima] plant to the US… Large-scale updraft [over] Japan from March 14 to 15 was found effective in lifting the particles [to the] jet stream that could carry the particles across the Pacific within 3 to 4 days [See study: On Mar. 15, Fukushima reactors emitted 100 quadrillion Bq of cesium into air — This one day was equal to total lifetime release from Chernobyl]… Some of the particles [had a] long-range atmospheric transport over — 10,000 km within 3 to 4 days… [R]adioactive materials were detected in that period over the east and west coasts of the U.S… In order for the particles to be transported with the jet stream, they must be lifted up from the surface boundary layer to the mid- or upper troposphere. Large-scale updraft was indeed observed… on March 14 through 15… [T]he westerlies in mid-March were thus particularly effective in the trans-Pacific transport of the radioactive materials…
Watch the numerical plume simulation here http://www.docin.com/p-773002550.html
Fukushima Watch: Tepco Two Months Behind on Cleaning Tainted Water http://blogs.wsj.com/japanrealtime/2015/01/26/fukushima-watch-tepco-two-months-behind-on-cleaning-tainted-water/ By MARI IWATA Tokyo Electric Power Co. says it will need an additional two months to process all the highly contaminated water in storage at the Fukushima Daiichi nuclear plant.
The power company previously said it would clean all the water by the end of March. A Tepco spokesman said Friday that the process had been slowed down by the need for workers to frequently clean the filters of the water processing system. He also said the system needed more initial adjustments than first expected when it came into use.
Tepco plans to give a more detailed outline of the water processing schedule in March, the spokesman said.
A large amount of groundwater keeps flowing underneath the reactors, creating about 300 to 400 tons a day of highly contaminated water. The water has been stored in about 1,000 tanks set up at the site.Tepco has been processing the water to remove most of the radioactive materials to reduce the contamination to a low level. The system is unable to remove tritium, a less harmful material.
The company now says it won’t finish processing the stored water until May. After that it will have sufficient capacity to deal with the daily inflows of groundwater.
Tepco suspends Fukushima No. 1 cleanup to probe fatal accidents Japan Times STAFF WRITER JAN 23, 2015 Tokyo Electric Power Co. has said it will suspend decommissioning work at the wrecked Fukushima No. 1 power plant until it completes safety checks related to two fatal accidents at its facilities in the prefecture this week……http://www.japantimes.co.jp/news/2015/01/23/national/tepco-suspends-fukushima-no-1-cleanup-to-probe-fatal-accidents/#.VMWMHtKUcnm
Japan’s deadly game of nuclear roulette, Japan Times, BY LEUREN MORET MAY 23 2004 Of all the places in all the world where no one in their right mind would build scores of nuclear power plants, Japan would be pretty near the top of the list.
The Japanese archipelago is located on the so-called Pacific Rim of Fire, a large active volcanic and tectonic zone ringing North and South America, Asia and island arcs in Southeast Asia. The major earthquakes and active volcanoes occurring there are caused by the westward movement of the Pacific tectonic plate and other plates leading to subduction under Asia.
Japan sits on top of four tectonic plates, at the edge of the subduction zone, and is in one of the most tectonically active regions of the world. It was extreme pressures and temperatures, resulting from the violent plate movements beneath the seafloor, that created the beautiful islands and volcanoes of Japan.
Nonetheless, like many countries around the world — where General Electric and Westinghouse designs are used in 85 percent of all commercial reactors — Japan has turned to nuclear power as a major energy source.
In fact the three top nuclear-energy countries are the United States, where the existence of 118 reactors was acknowledged by the Department of Energy in 2000, France with 72 and Japan, where 52 active reactors were cited in a December 2003 Cabinet White Paper.
The 52 reactors in Japan — which generate a little over 30 percent of its electricity — are located in an area the size of California, many within 150 km of each other and almost all built along the coast where seawater is available to cool them.
However, many of those reactors have been negligently sited on active faults, particularly in the subduction zone along the Pacific coast, where major earthquakes of magnitude 7-8 or more on the Richter scale occur frequently. The periodicity of major earthquakes in Japan is less than 10 years. There is almost no geologic setting in the world more dangerous for nuclear power than Japan — the third-ranked country in the world for nuclear reactors.
“I think the situation right now is very scary,” says Katsuhiko Ishibashi, a seismologist and professor at Kobe University. “It’s like a kamikaze terrorist wrapped in bombs just waiting to explode.”……..
Yoichi Kikuchi, a Japanese nuclear engineer who also became a whistle-blower, has told me personally of many safety problems at Japan’s nuclear power plants, such as cracks in pipes in the cooling system from vibrations in the reactor. He said the electric companies are “gambling in a dangerous game to increase profits and decrease government oversight.”
Sugaoka agreed, saying, “The scariest thing, on top of all the other problems, is that all nuclear power plants are aging, causing a deterioration of piping and joints which are always exposed to strong radiation and heat.”
Like most whistle-blowers, Sugaoka and Kikuchi are citizen heroes, but are now unemployed…….
It is not a question of whether or not a nuclear disaster will occur in Japan; it is a question of when it will occur. http://www.japantimes.co.jp/life/2004/05/23/to-be-sorted/japans-deadly-game-of-nuclear-roulette/#.VMMMH9KUcnk
January 22, 2015
Japan’s nuclear watchdog gave the green light to the operator of the wrecked Fukushima nuclear power plant to discharge pumped up groundwater into the sea if radioactive substances in the water are within safety standards.
The Jan. 21 decision by the Nuclear Regulation Authority concerns groundwater from 41 wells, called subdrains, close to the No. 1 to No. 4 reactor buildings at the Fukushima No. 1 plant.
Operator Tokyo Electric Power Co. will be obliged to remove radioactive substances in the groundwater at its decontamination facilities.
The water must meet certain criteria before it is released into the sea.
The conditions per liter of water are: that radioactive cesium is less than 1 becquerel; radioactive substances that emit beta rays are less than 3 becquerels; and the level of tritium is less than 1,500 becquerels.
Although TEPCO does not have the means to remove tritium at its decontamination facilities, the levels of contamination must be within safety limits.
The NRA said the volume of groundwater that flows into the reactor buildings will be reduced by one-half.
However, it remains unclear if the plan will be implemented as TEPCO is keen to get the approval of local residents, many of whom depend on fishing for their livelihoods.
The utility has been holding meetings with local fishery cooperatives since the summer to explain what it involved. Some members of the cooperatives seemed receptive to the plan, but others were not.
Source: Asahi Shimbun
Jan 22, 2015
Tokyo Electric Power Co. on Thursday said it will suspend the decommissioning of the Fukushima No. 1 power plant until it completes safety checks related to two fatal accidents at its facilities in the prefecture earlier this week.
“The most important thing is to thoroughly conduct safety checks,” Tepco spokesman Shinichi Kawamura told a news conference in Fukushima.
Decommissioning the wrecked plant involves many processes, but “we can’t tell when we will finish the checks for all work at this point,” Kawamura said, adding that it won’t take weeks.
On Monday, a 55-year-old subcontractor hired to work at the Fukushima No. 1 plant fell into a 10-meter-deep water tank during an inspection Monday. He was taken to a hospital but died the following day. Although the man was wearing a safety belt, he did not appear to be using it at the time.
On Tuesday, a subcontractor in his 40s died at the nearby Fukushima No. 2 plant after his head got crushed by an object during a concentrator inspection. The object was supposed to be held in place by a crane.
Kawamura said Tepco wants to pinpoint potentially unsafe places at the site, improve employee safety habits and ensure the procedures they are performing are safe.
For instance, Tepco will check whether adequate safety steps are being taken when handling heavy objects.
Since decommissioning work often requires the use of special industrial tools, workers must follow the required procedures to ensure their safety, Kawamura added.
The suspension will not affect the fuel-cooling and water-filtering operations, the utility said.
Source: Japan Times
January 21st, 2015
TV: Gov’t approves plan to ‘drain’ Fukushima nuclear waste into ocean — Professor: Monitoring necessary to detect ‘worrisome signals’ —
NHK, Jan 21, 2015 (emphasis added): Regulators approve Fukushima wastewater drainage — Japan’s nuclear regulator has approved a plan by [TEPCO] to drain filtered wastewater from the firm’s crippled Fukushima Daiichi plant into the sea… The firm also plans to reduce the level of radioactive material in the water before releasing it into the nearby Pacific. On Wednesday, the Nuclear Regulation Authority approved TEPCO’s plan to install drainpipes and a pumping system and to reduce the level of radioactive cesium-137 to less than one becquerel per liter.
NHK Transcript, Jan 21, 2015: Japanese regulators have approved a controversial plan by [TEPCO]. They say TEPCO officials can flush filtered waste water into the ocean… Fisherman: “We can’t trust Tepco… If they proceed with their plan the situation will surely go back to how it was before. I’m worried the government and Tepco will act to suit themselves.”
Wall St Journal, Jan 21, 2015: Japan’s nuclear regulator has officially called on [Tepco] to work toward discharging low-level contaminated water… just two days after a worker fell into [a tank] used to store contaminated water… Tepco is using a processing system [that] is unable to take out the tritium [and] is reluctant to release it into the ocean to avoid… criticism from neighboring countries and some nations with a Pacific Ocean coastline… there is no detailed study about tritium’s long-time effect on animal genes. Mamoru Takata, a Kyoto University professor and expert on radiation’s long-term effects, said monitoring would be necessary to detect any worrisome signals.
TEPCO: [ALPS] is designed to remove most remaining radioactive contaminants
TEPCO (pdf): (ALPS) — Removal capacity: Reduce 62 nuclides below the density limit
Asahi Shimbun in Jan. 2012: “To prevent a further contamination of the sea [Tepco] plans to remove about 1,000 kinds of radioactive materials from water”
Japan Atomic Energy Agency (pdf), Feb 2014: TOPICS Fukushima — [W]e carried out detailed calculations… for 1,200 radionuclides, and the results were incorporated into a database.
Dr. Gordon Edwards, court-certified nuclear expert, Aug 8, 2014 (50:00 in): It can’t be dumped into the ocean, because it’s completely unsafe because of these fission products. They have built over 1,000 large tanks, huge tanks… that contain this very, very radioactively contaminated water. At the moment they’re trying to filter out these fission products… It’s impossible for them to remove all those hundreds of radioactive materials. They know how to remove about 62 of them, but there’s other ones that they cannot.
January 20, 2015
Fission Stories #180
In early August 2014, the Tokyo Electric Power Company (TEPCO) announced that its latest analysis revealed the meltdown of the Unit 3 reactor at Fukushima Daiichi was worse than previously estimated.
Recall children’s books with dots and numbers? Children connect the dots to reveal pictures of clowns and puppies and spaceships and such.
TEPCO is essentially painting pictures using very few dots with no numbers. They keep running computer studies that put numbers almost randomly on the few dots they have to see what picture emerges. “Lo and behold” to quote a professor I had in college, different pictures emerge.
TEPCO doesn’t know when the Unit 3 core damage began
Or how much of the reactor core was damaged.
Or how and when the damaged core relocated after melting.
Or how, when, and where the molten burned through the reactor pressure vessel.
Or how it moved after it fell onto the containment’s concrete floor.
And they don’t know how much water, if any, was on the containment floor when the molten core joined it.
TEPCO fills in these information gaps with guesses. And they keep revising their results because they keep revising their guesses.
I choose not to play rate-a-guess. It would take me away from helping my nephew finish his connect-the-dots drawing. Only seven numbers remain to be connected. While it resembles a race car now, it might yet turn out to be a giraffe. Or maybe even a kitten.
Before I decide which TEPCO picture I most prefer, they are going to have to fetch more dots and put real numbers on as many of them as possible.
At some point in the next few years, TEPCO will maneuver a robot into the reactor area. That will reveal what the former reactor core looks like now. This information won’t answer all the questions, but it’ll number several more dots to support a meaningful analysis of what happened when.
Until then, TEPCO is just keeping their computer jockeys busy. They could get results of similar value using Ouija boards—and it would reduce their carbon footprint.
Source: Union of Concerned Scientists
“Implicates radiological hazard at distances otherwise overlooked”
January 21st, 2015
International Journal of Environmental Research and Public Health (pdf), University of Florida College of Medicine, Weill-Cornell Medical College, etc. (2014):
- The Fukushima Dai-ichi nuclear power plant accident is an example of a contemporary nuclear plant accident with serious implications.
- The Fukushima NPP accident has had health implications due to the high levels of radiation released and vast area over which the radiation has disperse.
- The significant radiation release, as likened to Chernobyl, reflects the context and severity of the Fukushima accident.
- The level of 137Cs that was released is likened to Chernobyl levels, with 100,000 TBq released.
- Radioactive plume dispersion occurs worldwide, far exceeding 300 miles previously mentioned. This should implicate radiological hazard at distances otherwise overlooked.
Potassium Iodide Distribution
- Radioactive plumes from the Chernobyl accident containing 131I caused benign and malignant thyroid nodules to develop, especially in children within a 310 miles radius of the incident.
- The current recommendation is for KI [potassium iodide] availability to people 200 miles from a NPP. Plume radii for nuclear events have been shown to exceed 300 [miles]. Extension of KI availability to 300 miles only further underscores the inadequacy of current preparedness plans.
- In regard to KI prophylaxis, TEPCO utilized 17,500 KI tablets for 2,000 onsite workers… with one individual receiving and taking 85 tablets.
- Radiological plumes containing 131I cause benign and malignant thyroid nodules to develop within a 300 mile radius… This necessitates KI pre-distribution to all schools, hospitals and other of-interest sites extending 300 miles from any nuclear reactor. Evacuation or sequestering is impossible in congested urban areas… There is currently virtually no compliance with [the] 20 miles radius KI pre-distribution law, section 127 of the Bioterrorism Act of 2002. In fact, there is little compliance with the 10 miles Ki pre-distribution radius law in the United States.
- Japan did not utilize KI for prophylaxis of the general public, acknowledging it was not prepared to act accordingly.
Jan. 21, 2015
Japan’s nuclear regulator has approved a plan by Tokyo Electric Power Company, or TEPCO, to drain filtered wastewater from the firm’s crippled Fukushima Daiichi plant into the sea.
TEPCO officials plan to pump up contaminated groundwater through wells built around structures housing the plant’s damaged reactors. The firm also plans to reduce the level of radioactive material in the water before releasing it into the nearby Pacific.
On Wednesday, the Nuclear Regulation Authority approved TEPCO’s plan to install drainpipes and a pumping system and to reduce the level of radioactive cesium-137 to less than one becquerel per liter. It also agreed with the firm’s policy of starting the drainage system gradually.
The regulator asked the utility to ensure that no wastewater leaks and to fully disclose measurements for radioactive material.
Tokyo Electric said it will not drain filtered wastewater until local residents agree to the plan.
The timing of such agreement is unclear, as local fishermen are worried that rumors of tainted seawater would affect their business.
Water tanks storing contaminated water at Fukushima Daiichi nuclear plant are seen in this photo from November
Jan 21, 2015
By Mari Iwata
Japan’s nuclear regulator has officially called on Tokyo Electric Power Co.9501.TO +0.63% to work toward discharging low-level contaminated water into the ocean from the Fukushima Daiichi nuclear plant.
The call on Wednesday comes just two days after a worker fell into one of the hundreds of tanks used to store contaminated water at the plant during an inspection, a fatal accident that has refocused attention on the need for improved safety measures and a longer term solution for the huge amounts of water in storage.
“Tokyo Electric Power must consider whether it (storing the water) is really necessary,” said Shunichi Tanaka, chairman of the Nuclear Regulation Authority, at a regular board meeting Wednesday. “It is surely harmful if it leads to the death of workers.”
The regulator discussed Wednesday a draft timetable for action by Tepco to address risks at the plant that sets out a 2017 start for discharging the water. The draft is likely to be approved next week.
The International Atomic Energy Agency already recommended more than a year ago that Tepco consider releasing water with low level tritium contamination in a controlled way so that it could focus on other issues.
A Tepco spokesman, speaking after Mr. Tanaka’s remarks, said the company wasn’t currently considering releasing the water into the ocean.
Contaminated water has been a constant headache for the operator of the plant since the triple meltdowns in March 2011. A large amount of groundwater is flowing into the site, adding 300 to 400 tons to the amount of highly contaminated water at the plant on a daily basis.
Tepco is using a processing system to remove radioactive material from the highly contaminated water, but the system is unable to take out the tritium. Tepco has been storing the tritium-contaminated water in about 1,000 tanks, but is reluctant to release it into the ocean to avoid adding to tension with local communities and criticism from neighboring countries and some nations with a Pacific Ocean coastline.
But the power company is close to running out of space to build new tanks at the plant and workers are increasingly under pressure to juggle their other duties with the ever-increasing workload of tank management, prompting the IAEA call in late 2013.
Tritium is considered one of the least harmful radioactive materials at nuclear plants. Water contaminated with tritium is discharged from plants elsewhere in the world after dilution.
However, there is no detailed study about tritium’s long-time effect on animal genes. Mamoru Takata, a Kyoto University professor and expert on radiation’s long-term effects, said monitoring would be necessary to detect any worrisome signals.
Plan OK’d for dumping Fukushima’s water into ocean after treatment
TOKYO (Kyodo) — The Nuclear Regulation Authority on Wednesday gave the green light to Tokyo Electric Power Co.’s plan to dump toxic groundwater pumped up at the stricken Fukushima Daiichi nuclear complex into the Pacific Ocean after removing almost all radioactive materials from it.
The plan is one of the measures aimed at curbing the amount of contaminated water building up at the seaside complex. But it remains uncertain when the operator may actually release the water.
Local fishermen have registered strong concerns that dumping the water will heighten consumer apprehension about marine pollution, and TEPCO has said it will not release the water unless it obtains consent from the locals.
The company plans to treat water pumped up through 42 of its wells at a water treatment facility at the plant. After treatment, the water will be temporarily stored in tanks to check whether the amount of radioactive materials left in it is within levels deemed safe for release into the sea.
According to TEPCO, the amount of radioactive water at the complex is believed to be increasing by some 350 tons every day as fresh, untainted groundwater is seeping into reactor buildings and mixing with toxic water generated in the process of cooling the reactors that suffered meltdowns in the 2011 nuclear disaster.
Separately, TEPCO is running a groundwater bypass that is aimed at pumping up untainted groundwater before it mixes with radioactive water. Since the earthquake- and tsunami-triggered disaster, the operator has dumped such water into the Pacific numerous times after confirming its safety.
Jan 20, 2015
Two workers died Tuesday in separate incidents at the Fukushima No. 1 power plant and the nearby No. 2 complex.
The fatality at No. 1 was first there since March, although there has been a rise in the number of industrial accidents at the site as Tokyo Electric Power Co. stepped up cleanup efforts and brought in more workers.
Tepco has said at least 40 workers were involved in accidents at No. 1 from last April to November, prompting labor inspectors last week to call for thorough preventive measures.
The utility has routinely pledged to improve work conditions at the site.
A 55-year-old worker at No. 1 fell into a 10-meter-high water tank during inspections Monday. He was taken to a hospital but was confirmed dead in the early hours of Tuesday.
Later, a worker in his 40s at the No. 2 plant, which escaped severe damage in the 2011 earthquake and tsunami, died after equipment fell on him.
In a statement, Akira Ono, manager of the No. 1 plant, expressed sorrow for the death of the first worker, who was not named but was identified as an employee of construction company Hazama Ando Corp.
“We are deeply sorry for the death of the worker and express our deepest condolences to the family,” Ono said. “We promise to implement measures to ensure that such tragedy does not occur again.”
Hazama Ando had no immediate comment.
The number of accidents at Fukushima No. 1 has almost doubled this fiscal year to 55. The increase came as Tepco ramped up cleanup efforts and doubled the number of workers at the site to nearly 7,000.
In March, a worker died after being buried in gravel while digging a ditch.
Tepco has been widely criticized for its handling of the cleanup. Until last year it struggled to contain leaks of radioactive water from hastily built tanks at the site, and it has repeatedly promised to improve working conditions.
Most workers inside the plant are contract laborers hired by multiple layers of construction companies. Reporters in 2013 revealed widespread labor abuses, including workers who said their pay was skimmed and that there was little scrutiny of working conditions.
“It’s not just the number of accidents that has been on the rise. It’s the serious cases, including deaths and serious injuries that have risen,” said Katsuyoshi Ito, a local labor inspector overseeing Fukushima No. 1. “We have asked Tepco to improve the situation.”
Source: Japan Times