Tag Archives: Fukushima Dai-ichi nuclear-power plant

Forever Fukushima: Cleaning Up the Huge Mess

By the end of 2019, Japan further delayed the removal of thousands of spent fuel units that remain in cooling pools since the 2011 disaster The government and the plant operator, Tokyo Electric Power Co., are keeping a 30- to 40-year completion target.

More than 4,700 units of fuel rods remain at the three melted reactors and two others that survived the 2011 earthquake and tsunami. They pose a high risk because their storage pools are uncovered and a loss of water in case of another major disaster could cause the fuel rods to melt, releasing massive radiation. Their removal at Units 1 and 2, after repeated delays, is now postponed by up to 10 years from the initial target of 2018, with more preparation needed to reduce radiation and clear debris and other risks.

Fuel rod removal at the Unit 1 reactor pool will begin sometime in 2027-2028, after debris is cleaned up and a huge rooftop cover installed to contain radioactive dust. Fuel removal at Unit 2 pool is to begin in 2024-2026. Work at the Unit 3 reactor pool began in April 2019 and all 566 units will be removed by March 2021. TEPCO has emptied the pool at Unit 4, which was offline and only suffered building damage, and aims to have all remaining rods in reactor pools removed by 2031 for safer storage in dry casks.

TEPCO has been unable to release the 1.2 million tons of treated but still radioactive water kept in nearly 1,000 tanks at the plant, fearing public repercussions and the impact on the area’s struggling fishing and agriculture. The amount of water is growing by 170 tons daily because it is used to cool the melted fuel inside the reactors.

The Ministry of Economy, Trade and Industry recently drafted a proposal to release the water to the sea or the air, or a combination of both. TEPCO says it can only store up to 1.37 million tons, or until the summer of 2022. Time is limited because preparation is needed before any water release. TEPCO and the government say the tanks pose risks if they were to spill their contents in another major earthquake, tsunami or flood…. The water is still somewhat contaminated, but TEPCO says further treatment can remove all but radioactive tritium to levels allowed for release. Experts say tritium is not harmful to humans in small amounts and has been routinely released from nuclear plants around the world.

Removing an estimated 880 tons of molten fuel from Fukushima’s three melted reactors is the toughest and unprecedented challenge. It’s six times the amount dealt with in the aftermath of the 1979 Three Mile Island partial core melt in the United States.  Removal is to begin in 2021 at Unit 2, where robotic probes have made more progress than at Units 1 and 3. A robotic arm was developed to enter the reactor from the side to reach the melted fuel, which has largely fallen to the bottom of the primary containment vessel… The first decade through 2031 is a crucial phase that will affect future progress…

Japan has yet to develop a plan to dispose of the highly radioactive melted fuel and other debris that come out of the reactors. TEPCO will compile a plan for those after the first decade of melted fuel removal. Managing the waste will require new technologies to reduce its volume and toxicity. TEPCO and the government say they plan to build a site to store waste and debris removed from the reactors, but finding one and obtaining public consent will be difficult.

Additionally, there will be an estimated 770,000 tons of solid radioactive waste by 2030, including contaminated debris and soil, sludge from water treatment, scrapped tanks and other waste. They will be sorted, treated and compacted for safe storage under a plan to be compiled by 2028.

The government says Fukushima’s decommissioning cost is estimated at 8 trillion yen ($73 billion), though adding compensation, decontamination of surrounding areas and medium-term storage facilities would bring the total to an estimated 22 trillion yen ($200 billion). The Japan Center for Economic Research, a think tank, estimates that decommissioning alone would cost 51 trillion yen ($470 billion) if the water is not released and tritium removal technology is pursued.

More than 10,000 workers will be needed annually in coming years, about one third assigned to work related to the radioactive water. 

Excerpts from MARI YAMAGUCHI,  Japan revises Fukushima cleanup plan, delays key steps, Associated Press, Dec. 27, 2019

A Huge Headache: the Radioactive Water at Fukushima

What to do with the enormous amount of radioactive  water, which grows by around 150 tons a day at Fukushima, is a thorny question, with controversy surrounding a long-standing proposal to discharge it into the sea, after extensive decontamination.  The water comes from several different sources: Some is used for cooling at the plant, which suffered a meltdown after it was hit by a tsunami triggered by a massive earthquake in March 2011.  Groundwater that seeps into the plant daily, along with rainwater, add to the problem.

A thousand, towering tanks have now replaced many of the cherry trees that once dotted the plant’s ground. Each can hold 1,200 tons, and most of them are already full.  “We will build more on the site until the end of 2020, and we think all the tanks will be full by around the summer of 2022,” said Junichi Matsumoto, an official with the unit of plant operator TEPCO in charge of dismantling the site.

TEPCO has been struggling with the problem for years, taking various measures to limit the amount of groundwater entering the site.  There is also an extensive pumping and filtration system, that each day brings up tons of newly contaminated water and filters out as many of the radioactive elements as possible.

The hangar where the decontamination system runs is designated “Zone Y” — a danger zone requiring special protections.  All those entering must wear elaborate protection: a full body suit, three layers of socks, three layers of gloves, a double cap topped by a helmet, a vest with a pocket carrying a dosimeter, a full-face respirator mask and special shoes.  Most of the outfit has to burned after use.

“The machinery filters contain radionuclides, so you have to be very protected here, just like with the buildings where the reactors are,” explained TEPCO risk communicator Katsutoshi Oyama.  TEPCO has been filtering newly contaminated water for years, but much of it needs to go through the process again because early versions of the filtration process did not fully remove some dangerous radioactive elements, including strontium 90.

The current process is more effective, removing or reducing around 60 radionuclides to levels accepted by the International Atomic Energy Agency (IAEA) for water being discharged.  But there is one that remains, which cannot be removed with the current technology: tritium.

Tritium is naturally present in the environment, and has also been discharged in its artificial form into the environment by the nuclear industry around the world.  There is little evidence that it causes harm to humans except in very high concentrations and the IAEA argues that properly filtered Fukushima water could be diluted with seawater and then safely released into the ocean without causing environmental problems.

But those assurances are of little comfort to many in the region, particularly Fukushima’s fishing industry which, like local farmers, has suffered from the outside perception that food from the region is unsafe.

Karyn Nishimura, At Fukushima plant, a million-ton headache: radioactive water, Japan Times, Oct. 7, 2019
 

Can Nuclear Power Beat Climate Change?

The 2019 World Nuclear Industry Status Report (WNISR2019) assesses the status and trends of the international nuclear industry and analyzes the potential role of nuclear power as an option to combat climate change. Eight interdisciplinary experts from six countries, including four university professors and the Rocky Mountain Institute’s co-founder and chairman emeritus, have contributed to the report.

While the number of operating reactors has increased over the past year by four to 417 as of mid-2019, it remains significantly below historic peak of 438 in 2002.  Nuclear construction has been shrinking over the past five years with 46 units underway as of mid-2019, compared to 68 reactors in 2013 and 234 in 1979. The number of annual construction starts have fallen from 15 in the pre-Fukushima year (2010) to five in 2018 and, so far, one in 2019. The historic peak was in 1976 with 44 construction starts, more than the total in the past seven years.

WNISR project coordinator and publisher Mycle Schneider stated: “There can be no doubt: the renewal rate of nuclear power plants is too slow to guarantee the survival of the technology. The world is experiencing an undeclared ‘organic’ nuclear phaseout.”  Consequently, as of mid-2019, for the first time the average age of the world nuclear reactor fleet exceeds 30 years.

However, renewables continue to outpace nuclear power in virtually all categories. A record 165 gigawatts (GW) of renewables were added to the world’s power grids in 2018; the nuclear operating capacity increased by 9 GW. Globally, wind power output grew by 29% in 2018, solar by 13%, nuclear by 2.4%. Compared to a decade ago, nonhydro renewables generated over 1,900 TWh more power, exceeding coal and natural gas, while nuclear produced less.

What does all this mean for the potential role of nuclear power to combat climate change? WNISR2019 provides a new focus chapter on the question. Diana Ürge-Vorsatz, Professor at the Central European University and Vice-Chair of the Intergovernmental Panel on Climate Change (IPCC) Working Group III, notes in her Foreword to WNISR2019 that several IPCC scenarios that reach the 1.5°C temperature target rely heavily on nuclear power and that “these scenarios raise the question whether the nuclear industry will actually be able to deliver the magnitude of new power that is required in these scenarios in a cost-effective and timely manner.”

Over the past decade, levelized cost estimates for utility-scale solar dropped by 88%, wind by 69%, while nuclear increased by 23%. New solar plants can compete with existing coal fired plants in India, wind turbines alone generate more electricity than nuclear reactors in India and China. But new nuclear plants are also much slower to build than all other options, e.g. the nine reactors started up in 2018 took an average of 10.9 years to be completed. In other words, nuclear power is an option that is more expensive and slower to implement than alternatives and therefore is not effective in the effort to battle the climate emergency, rather it is counterproductive, as the funds are then not available for more effective options.

Excerpts from WNISR2019 Assesses Climate Change and the Nuclear Power Option, Sept. 24, 2019

Where to Go? 1 Million Tons Radioactive Water at Fukushima

In August 2019, Tepco projected that storage of radioactive water at the Fukushima nuclear plant would reach full capacity by around summer 2022 even after the expansion — the first time it has issued such a precise estimate.  According to Tepco, the Fukushima No. 1 plant had 960 massive tanks containing 1.15 million tons of treated water as of July 18, 2019. Water that has touched the highly radioactive melted fuel debris has been cleaned up through water treatment machines and is stored in the tanks, but the high-tech treatment machines are able to remove most radionuclides except tritium. The plant currently sees an increase of contaminated water by 170 tons a day, Tepco says.

Releasing tritium-tainted water into the sea in a controlled manner is common practice at nuclear power plants around the world, and it was generally considered the most viable option as it could be done quickly and would cost the least.  The head of the Nuclear Regulation Authority, Toyoshi Fuketa, has long said that releasing the treated water into the sea is the most reasonable option, but people in Fukushima, especially fishermen, fear it will damage the region’s reputation.

Addressing those concerns, the government panel, launched in November 2016, has been looking for the best option in terms of guarding against reputational damage. Injecting it into the ground, discharging it as steam or hydrogen, or solidification followed by underground burial have all been on the table. Under the current plan, Tepco is set to increase the tank space to store 1.37 million tons of water a total, but estimates show that will only last until summer 2022.  But the more space it creates, the bigger the decommissioning headache becomes.

Excerpts from KAZUAKI NAGAT, Fukushima nuclear plant to run out of tanks to store tritium-laced water in three years, Tepco says, Japan Times, Aug. 9, 2019
BY KAZUAKI NAGATA

Never-Ending CleanUp: Fukushima

 The operator of Japan’s wrecked Fukushima nuclear plant completed in April 2019 the removal of the first fuel rods from a cooling pool high up in a badly damaged reactor building, a rare success in the often fraught battle to control the site.  The batch of 22 unused fuel assemblies, which each contain 50-70 of the fuel rods, was transferred by a trailer to a safer storage pool, the last day of a four-day operation, Tokyo Electric Power Co, or Tepco, said in a statement.

The company must carefully pluck more than 1,500 brittle and potentially damaged assemblies from the unstable reactor No.4., the early stages of a decommissioning process following the 2011 earthquake and tsunami that wrecked the site.

Tepco estimates removing the damaged assemblies from reactor No.4 alone will take a year. Some experts say that timeline is ambitious.  Still, it is an urgent operation. They are being stored 18 meters (59 feet) above ground level in a building that has buckled and tilted and could collapse if another quake strikes.  Carefully plucking the damaged fuel assemblies from the reactor building is being seen as a test of Tepco’s ability to move ahead with decommissioning the whole facility – a task likely to cost tens of billions of dollars and take decades.  The removal has to be conducted under water. If the rods are exposed to air or if they break, huge amounts of radioactive gases could be released into the atmosphere. Each assembly weighs around 300 kg (660 pounds) and is 4.5 meters (15 feet) long.  The hazardous removal operation has been likened by Arnie Gundersen, a veteran U.S. nuclear engineer and director of Fairewinds Energy Education, to trying to pull cigarettes from a crushed pack

Exerpts from In Start of Long Operation, Fukushima Removes First Fuel Rods, Reuters, April 2019

A Never-Ending Disaster: radioactive water at Fukushima

A Greenpeace report details how plans to discharge over 1 million tonnes of highly contaminated water into the Pacific Ocean was proposed by a Japanese government task force.  According to Greenpeace.

“The decision not to develop water processing technology that could remove radioactive tritium was motivated by short term cost cutting not protection of the Pacific ocean environment or the health and livelihoods of communities along the Fukushima coast,” said Kazue Suzuki, Energy Campaigner at Greenpeace Japan. “  The report concludes that the water crisis remains unresolved, and will be for the foreseeable future. The only viable option to protect the environment and the communities along the Fukushima coast being long term storage for the contaminated water.

The discharge option for water containing high levels of radioactive tritium was recommended as least cost by the Government’s Tritiated Water Task Force and promoted by Japan’s Nuclear Regulation Authority (NRA). The Task Force concluded in 2016 that “sea discharge would cost 3.4 billion yen (US$30 million) and take seven years and four months to complete. It concluded that this was cheapest and quickest of the five methods.” However, technical proposals for removing tritium were submitted to the same Government Task Force by multiple nuclear companies with estimated costs ranging from US$2-US$20 billion to US$50-US$180 billion depending on the technology used. These were dismissed as not viable but without detailed technical consideration.

TEPCO has claimed since 2013 that its ALPS technology would reduce radioactivity levels “to lower than the permissible level for discharge.” However, in September 2018 TEPCO admitted that the processing of over 800,000 tons of contaminated water in 1000 storage tanks, including strontium, had failed to remove radioactivity to below regulatory limits, including for strontium-90, a bone seeking radionuclide that causes cancer. TEPCO knew of the failure of the technology from 2013. The Greenpeace report details technical problems with the ALPS system.

The Fukushima Daiichi site, due its location, is subject to massive groundwater contamination which TEPCO has also failed to stop. Each week an additional 2-4000 tonnes of contaminated water is added to the storage tanks.

Excerpts from Technical failures increase risk of contaminated Fukushima water discharge into Pacific, Greenpeace Press Release,  Jan. 22, 2019

Devil’s Idea for Tokyo’s End: Fukushima

By late March 2011… after tsunami struck the Fukushima Daiichi plant—it was far from obvious that the accident was under control and the worst was over. Chief Cabinet Secretary Yukio Edano feared that radioactive material releases from the Fukushima Daiichi plant and its sister plant (Fukushima Daini) located some 12 km south could threaten the entire population of eastern Japan: “That was the devil’s scenario that was on my mind. Common sense dictated that, if that came to pass, then it was the end of Tokyo.”

Prime Minister Naoto Kan asked Dr. Shunsuke Kondo, then-chairman of the Japanese Atomic Energy Commission, to prepare a report on worst-case scenarios from the accidenta .  Dr. Kondo led a 3-day study involving other Japanese experts and submitted his report (Kondo, 2011) to the prime minister on March 25, 2011. The existence of the report was initially kept secret because of the frightening nature of the scenarios it described. An article in the Japan Times quoted a senior government official as saying, “The content [of the report] was so shocking that we decided to treat it as if it didn’t exist.” …

One of the scenarios involved a self-sustaining zirconium cladding fire in the Unit 4 spent fuel pool. Radioactive material releases from the fire were estimated to cause extensive contamination of a 50- to 70-km region around the Fukushima Daiichi plant with hotspots significant enough to require evacuations up to 110 km from the plant. Voluntary evacuations were envisioned out to 200 km because of elevated dose levels. If release from other spent fuel pools occurred, then contamination could extend as far as Tokyo,…There was particular concern that the zirconium cladding fire could produce enough heat to melt the stored fuel, allowing it to flow to the bottom of the pool, melt through the pool liner and concrete bottom, and flow into the reactor building.

Lessons Learned from the Fukushima Daiichi Accident for Spent Fuel Storage: The U.S. nuclear industry and its regulator should give additional attention to improving the ability of plant operators to measure real-time conditions in spent fuel pools and maintain adequate cooling of stored spent fuel during severe accidents and terrorist attacks. These improvements should include hardened and redundant physical surveillance systems (e.g., cameras), radiation monitors, pool temperature monitors, pool water-level monitors, and means to deliver pool makeup water or sprays even when physical access to the pools is limited by facility damage or high radiation levels….

[At nuclear power plants there must be…adequate separation of plant safety and  security systems so that security systems can continue to function independently if safety systems are damaged. In particular, security systems need to have independent, redundant, and protected power sources…]

Excerpts from Lessons Learned from the Fukushima Accident for Improving
Safety and Security of U.S. Nuclear Plants: Phase 2, US National Academies, 2016