Tagged: TEPCO

IAEA Delivers Final Report on Decommissioning Efforts at Fukushima Daiichi

IAEA Delivers Final Report on Decommissioning Efforts at Fukushima Daiichi

TEPCO Fukushima Daiichi Nuclear Power Station

IAEA experts visiting TEPCO’s Fukushima Daiichi Nuclear Power Station on 27 November 2013 looked at the fuel assembly removal process in Reactor Unit 4. Last week, TEPCO began moving nuclear fuel assemblies from Reactor Unit 4 to the Common Spent Fuel Pool. (Photo: G. Webb/IAEA)

The International Atomic Energy Agency (IAEA) delivered a report on 12 February 2014 to the government of Japan describing the findings of a two-part review of the nation’s efforts to plan and implement the decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Station (NPS).

At Japan’s request, the IAEA organized two expert teams to provide an independent review of Japan’s Mid-and-Long-Term Roadmap towards the Decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Station Units 1-4. The first team visited Japan from 15 to 22 April 2013 and the second from 25 November to 4 December 2013.

“Japan has established a good foundation to improve its strategy and to allocate the necessary resources to conduct the safe decommissioning of Fukushima Daiichi,” said team leader Juan Carlos Lentijo, IAEA Director of Nuclear Fuel Cycle and Waste Technology.” The situation, however, remains very complex, and there will continue to be challenging issues that must be resolved to ensure the plant’s long-term stability.”

The expert teams examined a wide variety of issues relating to decommissioning the power plant, including Tokyo Electric Power Company’s (TEPCO’s) efforts to remove fuel assemblies from Reactor Unit 4’s Spent Fuel Pool and to manage the growing volume of contaminated water at the site.

The teams held extensive discussions with senior officials from the Ministry of Economy, Trade and Industry (METI) and TEPCO. The teams also visited the nuclear accident site twice to gain first-hand information on the conditions at the power plant and the progress made toward decommissioning the facility.

Read more here http://www.iaea.org/newscenter/news/2014/decommissioning.html

Source: IAEA

 

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All systems ready for Fukushima fuel removal

All systems ready for Fukushima fuel removal

Engineers at Fukushima Daiichi have done final checks before they begin removing fuel from unit 4’s storage pond, the highest priority safety-related task in the site’s decommissioning.

Checks within Fukushima Daiichi 4 cover, November 2013 (Tepco) 460x306

Technicians within the new building cover. The empty reactor vessel is beneath the circular section, the rectangular part is the used fuel pool (Image: Tepco)

A fuel transport container will be placed in the pool using the main crane. Workers will then use the smaller refuelling crane to move fuel assemblies one by one from their vertical storage racks to the container. When this is full it will be sealed, lifted from the water by the main crane, placed on the service floor for decontamination and then taken through a special route to a vehicle that will move it across the site to be unloaded at the site’s shared storage facility. This process will be repeated until the pool is empty.

With a total of 1533 fuel assemblies in the pool (1331 used, 202 unused) this is expected to take until the end of 2014. Tepco will move the fuel during the day and clean dust and debris from the pool water during the night. Two containers will be used in relay.

Fuel transport container at Fukushima Daiichi 4, November 2013 (Tepco) 460x306

The Nuclear Regulatory Authority granted its approval for the security and radiological protection aspects of the work yesterday, and Tepco engineers conducted final functional checks of the cranes using non-radioactive dummy fuel today. One more round of feedback from local people is required before the operations begin, perhaps as soon as next week.

One of the fuel containers pictured during training tests (Inage: Tepco)
Checking a crane at Fukushima Daiichi 4, November 2013 (Tepco) 460x306
Inspecting the controls of newly-installed cranes (Image: Tepco)

Unit 4 was off line for maintenance at the time of the 2011 accident with its full core load of fuel, as well as used fuel from previous operation, stored in a fuel pool at the top of the reactor building. Although this meant there was no possibility of a reactor accident at unit 4, there was a risk of the pool overheating. The stability of the pool was then reduced by major structural damage to the building caused by the ignition of hydrogen that leaked through ventilation systems shared with unit 3.

The building has since been reinforced, and thousands of tonnes of debris and rubble have been removed from its roof. The new cover has been constructed with all the fuel handling equipment of a normal nuclear power plant and inspections of the pool have shown the fuel to be undamaged and not suffering from corrosion.

Source: World Nuclear News

Fukushima nuclear operator Tepco ‘should split up’

Fukushima nuclear operator Tepco ‘should split up’

File photo: Workers wearing protective suits and masks are seen next to the number four reactor at Tokyo Electric Power Company's (Tepco) tsunami-crippled Fukushima Daiichi nuclear power plant in Fukushima prefecture, 6 March 2013

The operator of Japan’s stricken Fukushima nuclear power plant should be broken up, a committee is set to propose according to unnamed sources.

The ruling party panel wants part of the Tokyo Electric Power Company in charge of cleaning to be separated.

Fukushima has been beset by problems – including toxic water leaks – since it was damaged by the earthquake and tsunami of March 2011.

The clean up is expected to take 40 years and cost at least $100bn (£62bn).

Nearly 100,000 people are still unable to return to their homes because of high levels of radiation.

Previous Fukushima problems

  • 9 Oct Six workers at Japan’s Fukushima nuclear plant have been doused in radioactive water, Tepco says
  • 7 Oct A plant worker accidentally switches off power to pumps used for cooling damaged reactors
  • 3 Oct Tepco says there is a radioactive water leak after workers overfill a storage tank
  • 21 Aug Japan’s nuclear agency upgrades Fukushima alert level
  • 20 Aug Tepco says 300 tonnes of radioactive water has leaked from a storage tank into the ground
  • July Tepco for the first time admits radioactive water is going into the sea
  • June Tepco says radioactive water leaking from a storage tank to the ground
  • April Tepco suspects a fresh radioactive water leak at Fukushima
  • March Tepco suspects a rodent may have been behind a power cut that shut down cooling systems
  • Dec 2011 Contaminated water leaks from a treatment system, caused by a crack in the foundation

Cooling systems for reactors at Fukushima were knocked out during the disaster, causing meltdowns at three of them.

Water is being pumped in to cool the reactors. However, this creates large amounts of contaminated water that must be stored securely.

Some of the water has leaked from the tanks, pipes and damaged structures, leading to concerns contaminated water is mixing with groundwater that is flowing into the sea.

Workers have been batting to contain the toxic water leaks and there are reports that they are suffering from low morale and exhaustion.

The panel from the Liberal Democratic Party (LDP) is tasked with the recovery of areas devastated by the earthquake and tsunami.

The panel says Japan’s Fukushima disaster needs to be dealt with by a small, specialist company focused entirely on the clean-up operation, local media report.

It is expected to hand their proposals to Prime Minister Shinzo Abe next week, Reuters news agency says, citing a source familiar with the matter.

It will recommend “creating a clear and realistic organisation” for operations at Fukushima, the source added.

The proposals come after months of intense criticism of Tepco, which owns the plant and is currently responsible for the clean-up.

The idea is that the part of Tepco responsible for the clean-up would be split off, while the rest of the corporation would be allowed to return to its core business of generating electricity, says the BBC’s Rupert Wingfield-Hayes in Tokyo.

Source: BBC News 

Fukushima nuclear plant: Radioactive water leak found

Fukushima nuclear plant: Radioactive water leak found

Aerial photo taken on 9 July 2013 of the Fukushima Dai-ichi nuclear power plant in Fukushima prefecture, northern Japan
(The tsunami knocked out cooling systems to the reactors at Fukushima)

Radioactive water has leaked from a storage tank into the ground at Japan’s Fukushima plant, its operator says.

Tokyo Electric Power Company (Tepco) said the leak of at least 300 tonnes of the highly radioactive water was discovered on Monday.

The plant, crippled by the earthquake and tsunami in 2011, has seen a series of water leaks and power failures.

The tsunami knocked out cooling systems to the reactors, three of which melted down.

An employee discovered the leak on Monday morning, Tepco said in a statement.

Officials described the leak as a level-one incident – the lowest level – on the International Nuclear and Radiological Event Scale (Ines), which measures nuclear events.

This is the first time that Japan has declared such an event since the 2011 earthquake and tsunami, however.

Under the Ines, events have seven levels starting with Level 0 (“without safety significance”), and Levels 1-3 denoting “incidents” and Levels 4-7 denoting “accidents”.

A puddle of the contaminated water was emitting 100 millisieverts an hour of radiation, Kyodo news agency said.

Masayuki Ono, general manager of Tepco, told Reuters news agency: “One hundred millisieverts per hour is equivalent to the limit for accumulated exposure over five years for nuclear workers; so it can be said that we found a radiation level strong enough to give someone a five-year dose of radiation within one hour.”

More monitoring

A Tepco official told a press conference on Tuesday that the water probably leaked from a tank after escaping a concrete barrier.

Workers were pumping out the puddle and the remaining water in the tank and would be transferring it to other containers, Kyodo added.

Water is being pumped into the reactors, after cooling systems were knocked out by the tsunami.

Hundreds of tanks were built to store the contaminated water. Some of them had experienced similar leaks since 2012, but not on this scale, a Tepco official said.

Tepco had been instructed to retrieve contaminated soil and to strengthen monitoring of the surrounding environment, a regulatory official told Agence-France Presse news agency.

No major changes in radiation levels outside the plant had been observed so far, the official added.

The incident comes days after Tepco admitted that as much as 300 tonnes of contaminated water a day was leaking from the damaged reactor buildings to the sea.

Source: BBC News

Japan oil use down as nuclear power boosted

Japan oil use down as nuclear power boosted

Japan oil use down as nuclear power boosted

Japan’s ten regional energy companies used less oil in July as more nuclear power was generated, according to new figures released today by the Federation of Electric Power Companies (FEPC) of Japan.

The group includes ten privately-owned firms including the owner of the ravaged Fukushima nuclear plant, Tokyo Electric Power Company (Tepco). Since the disaster in April 2011, most of the country’s nuclear plants closed, leaving a significant capacity gap which has had to be filled with more coal, oil and gas.

The companies’ use of heavy oil dropped to 1.09 million kilolitres, roughly a tenth less than in July 2012. In contrast nuclear capacity rose, with a year-on-year increase of 77.3% to 1.78 billion kWh.

Read the full article here http://www.energylivenews.com/2013/08/15/japan-oil-use-down-as-nuclear-power-boosted/

Source: Energy Live News

Fukushima radioactive water leak an ’emergency’

Fukushima radioactive water leak an ’emergency’

Aerial photo taken on 9 July 2013 of the Fukushima Dai-ichi nuclear power plant in Okuyama, Fukushima prefecture, northern Japan
(The crippled Fukushima plant has suffered water leaks and power cuts in recent months)

Japan’s nuclear watchdog has said the crippled Fukushima nuclear plant is facing a new “emergency” caused by a build-up of radioactive groundwater.

A barrier built to contain the water has already been breached, the Nuclear Regulatory Authority warned.

This means the amount of contaminated water seeping into the Pacific Ocean could accelerate rapidly, it said.

There has been spate of water leaks and power failures at the plant, devastated by the 2011 earthquake and tsunami.

Its operator, Tokyo Electric Power Company (Tepco), has been criticised heavily for its lack of transparency over the leaks.

‘Weak sense of crisis’

Tepco admitted for the first time last month that radioactive groundwater had breached an underground barrier and been leaking into the sea, but said it was taking steps to prevent it.

However, the head of a Nuclear Regulatory Authority task force, Shinji Kinjo, told the Reuters news agency on Monday that the countermeasures were only a temporary solution.

Tepco’s “sense of crisis is weak,” Mr Kinjo said. “This is why you can’t just leave it up to Tepco alone”

“Right now, we have an emergency,” he added.

If the underground barrier is breached, the watchdog warns, the water could start to seep through shallower areas of earth.

Once it reaches the surface, it could start to flow “extremely fast”, says Mr Kinjo.

Contaminated water could rise to the ground’s surface within three weeks, the Asahi newspaper predicted on Saturday.

The contaminated water is thought to have come from the 400 tonnes of groundwater pumped into the plant every day to cool the reactors.

Tepco ‘in trouble’

Tepco admitted on Friday that a cumulative 20 trillion to 40 trillion becquerels of radioactive tritium may have leaked into the sea since the disaster.

It has been clear for months now that the operators of the Fukushima plant are in deep trouble, says the BBC’s Rupert Wingfield-Hayes.

The only course of action, he continues, is to pump water out. But this has to be stored, and more than 1,000 giant holding tanks surrounding the plant are nearly all full, he adds.

Tepco said on Monday it plans to start pumping out a further 100 tonnes of groundwater a day.

 Source: BBC News

Fukushima nuclear plant: Steam seen at reactor building

Fukushima nuclear plant: Steam seen at reactor building

Aerial photo taken on 9 July 2013 of the Fukushima Dai-ichi nuclear power plant in Okuyama, Fukushima prefecture, northern Japan
(The crippled Fukushima plant has faced waters leaks and power cuts in recent months)
Steam has been seen rising from a reactor building at Japan’s Fukushima nuclear plant, its operator says.

Tokyo Electric Power Company (Tepco) said there was no emergency situation and there were no signs of increased radiation in the area.

It says it is investigating what is causing the steam at the damaged No 3 reactor building.

The plant, crippled by the earthquake and tsunami in 2011, has seen a series of water leaks and power failures.

The tsunami knocked out cooling systems to the reactors, three of which melted down.

Water is being pumped into the reactors to cool them, but that has left Tepco with the problem of storing the contaminated waste water.

‘Monitor closely’

A worker first noticed the steam after reviewing camera footage taken of the building, Tepco said.

The operator said in a statement there was a “steam-like gas wafting through the air near the central part of the fifth floor [equipment storage pool side]” of the No 3 reactor building.

The reactor water injection and the cooling of the spent fuel pool were “continuing stably”, Tepco said. There were also no significant change in the temperature of the reactor.

“We will continue to monitor the status closely,” the statement added.

“We do not believe an emergency situation is breaking out although we are still investigating what caused this,” a spokesman told Agence-France Presse news agency.

Mayumi Yoshida, another Tepco spokesperson, told Reuters news agency: “We think it’s possible that rain made its way through the reactor building and having fallen on the primary containment vessel, which is hot, evaporated creating steam.”

This is the latest in a series of problems that the Fukushima power plant has faced in recent months.

Last week, a sharp increase in radioactive cesium was detected in groundwater 25m (82ft) from the sea.

In June, radioactive water was also found to be leaking from a storage tank.

Experts say years of work lie ahead before the problems at the plant can be fully contained.

Source: BBC News