Far too unsafe to be dumped soon

29 Septembre 2018

September 29, 2018

Treated water at Fukushima nuclear plant still radioactive

https://mainichi.jp/english/articles/20180929/p2g/00m/0dm/055000c

TOKYO (AP) -- The operator of Japan's wrecked Fukushima nuclear plant said Friday that much of the radioactive water stored at the plant isn't clean enough and needs further treatment if it is to be released into the ocean.

Tokyo Electric Power Co. and the government had said that treatment of the water had removed all radioactive elements except tritium, which experts say is safe in small amounts.

They called it "tritium water," but it actually wasn't.

TEPCO said Friday that studies found the water still contains other elements, including radioactive iodine, cesium and strontium. It said more than 80 percent of the 900,000 tons of water stored in large, densely packed tanks contains radioactivity exceeding limits for release into the environment.

TEPCO general manager Junichi Matsumoto said radioactive elements remained, especially earlier in the crisis when plant workers had to deal with large amounts of contaminated water leaking from the wrecked reactors and could not afford time to stop the treatment machines to change filters frequently.

"We had to prioritize processing large amounts of water as quickly as possible to reduce the overall risk," Matsumoto said.

About 161,000 tons of the treated water has 10 to 100 times the limit for release into the environment, and another 65,200 tons has up to nearly 20,000 times the limit, TEPCO said.

Matsumoto said the plant will treat the water further to ensure contamination levels are reduced to allowable limits.

He was responding to growing public criticism and distrust about the status of the water.

More than 7 1/2 years since a massive March 2011 earthquake and tsunami destroyed three reactors at the plant, Japan has yet to reach a consensus on what to do with the radioactive water. Fishermen and residents oppose its release into the ocean. Nuclear experts have recommended the controlled release of the water into the Pacific as the only realistic option.

The release option faced harsh criticism at town meetings in Fukushima and Tokyo in late August, when TEPCO and government officials provided little explanation of the water contamination, which had been reported in local media days earlier.

TEPCO only says it has the capacity to store up to 1.37 million tons of water through 2020 and that it cannot stay at the plant forever.

Some experts say the water can be stored for decades, but others say the tanks take up too much space at the plant and could interfere with ongoing decommissioning work, which could take decades.

Treated water at Fukushima plant far too unsafe to be dumped soon

http://www.asahi.com/ajw/articles/AJ201809290029.html

THE ASAHI SHIMBUN

Steps to purify a radioactive water buildup at the stricken Fukushima No. 1 nuclear power plant have come to naught, forcing the operator, Tokyo Electric Power Co., to go back to the drawing board.

On Sept. 28, TEPCO acknowledged that about 80 percent of the water in giant storage tanks on the premises exceeded government standards for radioactive materials even though it had already been processed.

Some of the "processed" water showed concentrations of radioactive materials at more than about 20,000 times the standard used to determine if the water is safe enough to discharge into the ocean.

TEPCO has been treating the water with a device known as ALPS, or advanced liquid processing system. Water is accumulating at a rate of between 50,000 and 80,000 tons a year.

The latest study covered about 890,000 tons of the 940,000 tons of water that has gone through ALPS and is stored on-site.

Tests showed that strontium 90 was present in some tanks at levels of about 600,000 becquerels per liter of water, which is about 20,000 times the safety standard.

Strontium 90 has a half-life of about 29 years. It could lead to bone cancer or leukemia after being absorbed in the bones by breathing it, or ingesting it.

Until now, TEPCO had insisted that the ALPS device could remove 62 types of radioactive materials from the water. The only substance that could not be removed was tritium, a radioactive isotope of hydrogen.

When TEPCO decides on how to dispose of the contaminated water in the storage tanks, it plans to again process the water through the ALPS device before releasing it into the ocean.

This leaves TEPCO between a rock and a hard place as the device can currently process only 340 tons of water daily.

If once-processed water is sent through the device a second time, that would not only add to costs but require years of processing before all the water can be discharged safely.

TEPCO does not have the luxury of time as contaminated water continues to be generated at the rate of tens of thousands of tons annually in the form of either groundwater or water used to cool reactor cores that come into contact with the melted nuclear fuel in the three reactors that went into meltdown after the earthquake and tsunami disaster in 2011.

An additional problem is that so many storage tanks have been constructed on the grounds of the Fukushima plant that there will be no space for new ones by 2020.

TEPCO at least knows why so much of the stored water continues to register radioactive substances in alarmingly high concentrations.

It explained that a malfunction of the ALPS device in fiscal 2013 prevented processing of all highly contaminated water. Some of the water with high concentrations of radioactive materials likely mixed in with other water in the storage tanks.

Utility officials also pointed to a delay in the replacement of absorbent in the ALPS device used to remove the radioactive substances.

TEPCO promised to review the timing for the replacement of absorbent. However, it could not rule out the possibility that radioactive materials at levels exceeding safety standards would again be detected even if that step is taken.

The utility was also taken to task for releasing the measurement levels of radioactive materials on its website without providing an adequate explanation of what those figures actually meant.

At a public hearing in August in Fukushima Prefecture, local residents pointed out that the stored water contained radioactive materials other than tritium at levels exceeding safety standards.

In the seven-plus years since the triple meltdown at the Fukushima plant, TEPCO has released a voluminous amount of data about various measurements of radioactive materials, which has caused headaches for local residents who have no in-depth knowledge of what the figures mean.

The Ministry of Economy, Trade and Industry also bears some of the blame because it has been pushing TEPCO to accelerate the processing of contaminated water to show the world gathering in Japan for the 2020 Tokyo Olympics and Paralympics that the situation in Fukushima was under control and the region well on its way to rebuilding.

(This article was written by Yusuke Ogawa and Hiroshi Ishizuka. Noriyoshi Ohtsuki, a senior staff writer, and Chikako Kawahara contributed to the article.)

Treated water at Fukushima nuclear plant still radioactive: Tepco

https://www.japantimes.co.jp/news/2018/09/29/national/treated-water-fukushima-nuclear-plant-still-radioactive/#.W69CiPmYRLM

y Mari Yamaguchi

AP

Sep 29, 2018

The operator of the Fukushima No. 1 nuclear plant has said that much of the radioactive water stored at the plant isn’t clean enough and needs further treatment if it is to be released into the ocean.

Tokyo Electric Power Company Holdings Inc. and the government had said that treatment of the water had removed all radioactive elements except tritium, which experts say is safe in small amounts.

They called it “tritium water,” but it actually wasn’t.

Tepco said Friday that studies found the water still contains other elements, including radioactive iodine, cesium and strontium. It said more than 80 percent of the 900,000 tons of water stored in large, densely packed tanks contains radioactivity exceeding limits for release into the environment.

Tepco general manager Junichi Matsumoto said radioactive elements remained, especially earlier in the crisis when plant workers had to deal with large amounts of contaminated water leaking from the wrecked reactors and could not afford time to stop the treatment machines to change filters frequently.

“We had to prioritize processing large amounts of water as quickly as possible to reduce the overall risk,” Matsumoto said.

About 161,000 tons of the treated water has 10 to 100 times the limit for release into the environment, and another 65,200 tons has up to nearly 20,000 times the limit, Tepco said.

Matsumoto said the plant will treat the water further to ensure contamination levels are reduced to allowable limits.

He was responding to growing public criticism and distrust about the status of the water.

More than 7½ years since a massive March 2011 earthquake and tsunami destroyed three reactors at the plant, Japan has yet to reach a consensus on what to do with the radioactive water. Fishermen and residents oppose its release into the ocean. Nuclear experts have recommended the controlled release of the water into the Pacific as the only realistic option.

The release option faced harsh criticism at meetings in Fukushima and Tokyo in late August, when Tepco and government officials provided little explanation of the water contamination, which had been reported in local media days earlier.

Tepco only says it has the capacity to store up to 1.37 million tons of water through 2020 and that it cannot stay at the plant forever.

Some experts say the water can be stored for decades, but others say the tanks take up too much space at the plant and could interfere with ongoing decommissioning work that could take decades.