Possible Leak of Alpha and Beta Radiation Emitters at Transuranic Radioactive Waste Underground Storage Facility in New Mexico, DOE Official Doesn't Quantify the Leak

The facility, Waste Isolation Pilot Plant (WIPP), takes plutonium-contaminated waste from Los Alamos National Laboratory and other federal nuclear projects.

According to wiki,

The Waste Isolation Pilot Plant, or WIPP, is the world's third deep geological repository (after closure of Germany's Repository for radioactive waste Morsleben and the Schacht Asse II Salt Mine) licensed to permanently dispose of transuranic radioactive waste for 10,000 years that is left from the research and production of nuclear weapons.

(FYI, transuranic elements: the chemical elements with atomic numbers greater than 92 (the atomic number of uranium))

From Salon, quoting AP (2/16/2014; emphasis is mine):

Crews monitor NM nuclear repository for radiation

CARLSBAD, N.M. (AP) — Officials checking the presence of airborne radiation at an underground site in southeastern New Mexico where the U.S. government seals away low-grade nuclear waste say surface tests have detected no contamination.

Samples were taken at several sites around the Waste Isolation Pilot Plant after an air monitor found radiation on the underground levels of the facility around 11:30 p.m. Friday, the U.S. Department of Energy said in a news release.

No workers were underground at the time and no injuries or damages have been reported. A fire at the site earlier this month prompted an evacuation.

“Monitors at the WIPP boundary have confirmed there is no danger to human health or the environment,” the department said late Saturday night. “No contamination has been found on any equipment, personnel, or facilities.”

Energy Department spokesman Roger Nelson said that the 139 workers aboveground at the site near Carlsbad were told Saturday to stay where they were as a precaution. None of them tested positive for contamination, and all non-essential personnel were released, Nelson said.

The surface samples show no contamination has been detected, implying the leak was “not significant,” he said.

Nelson says the cause of the leak is not known yet. The devices that continuously monitor the air underground reached a threshold level that automatically switches the ventilation system into a filtered mode. He couldn’t quantify the level it takes to trigger the monitors, but says they’re sensitive. He says the monitors have been triggered in the past by radon fluctuations.

WIPP stores waste that emits alpha and beta radiation, which is in particulate form, so the risk is of inhalation not penetration, he said.

No one has been underground, and Nelson said he didn’t know when that would happen.

“We are going to take measurements and make sure we understand it” before sending in a team, he said.

U.S. Rep. Steve Pearce issued a statement saying, “WIPP has acted quickly and cautiously to ensure the safety of personnel and the local community.”

============================

The incident comes 10 days after an underground truck fire at the plant prompted an evacuation. Six people were treated for smoke inhalation on Feb. 5.

Nelson said the fire was in a different part of the site, about 1,000 feet away, from where the radiation was found.

Asked if the incidents were related, he said, “I just can’t think of a scenario where there would be a relationship.”

WIPP is the nation’s first and only deep geological nuclear waste repository. It takes plutonium-contaminated waste from Los Alamos National Laboratory and other federal nuclear projects.

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#Fukushima I NPP: TEPCO Now Admits Underestimation of Beta Nuclides in 167 Samples Since March 2011

The total number of samples for beta nuclide analyses from March 2011 to January 2014 is 20,866. It turns out that if the sample contains more than 200,000 Bq/Liter of beta nuclides, the instrument cannot accurately measure the radioactivity.

From Fukushima Minyu (2/15/2014):

167体で誤測定の可能性　ベータ線を出す放射性物質

Possibility of mistakes in measuring beta nuclides in 167 samples

東京電力が福島第１原発の汚染水測定でストロンチウム９０などベータ線を出す放射性物質の濃度を過小に推計していた問題で、東電は１４日、事故直後の２０１１（平成２３）年３月から今年１月末までに測定した試料１６７体について、正確な測定できず、測定値を過小に推計した可能性があるとする調査結果を発表した。いずれも実際の値はさらに上昇する見通し。

TEPCO underestimated the densities of beta nuclides including strontium-90 in the analyses of contaminated water at Fukushima I Nuclear Power Plant. On February 14, TEPCO announced the result of the investigation that says TEPCO underestimated [the densities of beta nuclides] in 167 samples taken and analyzed between March 2011 and the end of January 2014. The actual densities are expected to be much higher.

東電によると、１６７体は、海水や観測用井戸から採取した地下水や、敷地内の土壌など。

According to TEPCO, these 167 samples were taken from the seawater, groundwater from the observation wells, and soil inside the plant compound.

東電が原発事故直後から今年１月末までに測定したベータ線を出す放射性物質の件数は計２万８６６体。これまでの調査で、測定機器では１リットル当たり２０万ベクレルを超える試料は正確な値が測定されないことが判明しており、検体数を確認したところ１６７体に上った。東電は今後、これらの検体を測定し直し、正確な測定値を公表するとしている。

The total number of samples for beta nuclide analyses from immediately after the start of the nuclear accident and the end of January this year is 20,866. The investigation so far has revealed that the instrument [used by TEPCO] cannot accurately measure the samples with beta nuclides exceeding 200,000 Bq/Liter, and there are 167 such samples. TEPCO says the company will analyze these samples again, and publish the accurate results.

Only now TEPCO is allowed to admit to the mistake. Now that the 2020 Olympics will be held in Tokyo, and now that the Tokyo gubernatorial election is safely over, with the win by a pro-nuclear candidate with whom TEPCO is very comfortable working.

TEPCO correctly measured the sample with 5 million Bq/L of strontium-90, but they did not disclose the number because their measurement of all-beta including strontium-90 in the same sample was 0.9 million Bq/L, which was an impossibility. They sat on it, and sat on it until February 7, 2014.

According to tweets by nuclear experts, TEPCO has the analysis lab at Fukushima I Nuclear Power Plant with 30 staff members. According to these experts, it is barely adequate for the amount of work they have to do.

And where is the promise of "the national government at the forefront" by the Abe administration?

Now that the 2020 Olympics is in the bag and the governor of Tokyo is the highly blackmailable Masuzoe, Abe has moved on to his pet project - Constitutional amendment, which will be determined solely by him as the "CEO" of the nation.

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RO Waste Water Leak at #Fukushima: 2,200 mSv/Hr to 30 mSv/Hr Beta After Shielding Experiment

The images don't give you much confidence and may make you fear for the safety of workers from beta radiation exposure on skin who would be asked to perform this task on potentially over 350 huge tanks.

But the beta radiation (measured at 5 centimeter and expressed in 70 micrometer dose equivalent) did go down.

The experiment details, from TEPCO's Handout for the Press 9/5/2013 on H3 Area tank radiation shielding experiment:

1. Apply sealing material (which looks like putty) to the flange.

2. Place one to three acrylic sheets (15 x 10 x 1 centimeter).

3. Place two layers of rubber sheets (1.5m x 1m x 3mm) on the concrete (and put sand bags to hold them down).

Result:

2,200 mSv/hr --> 30 mSv/hr
500 mSv/hr --> 15 mSv/hr
70 mSv/hr --> 10 mSv/hr

TEPCO has already said they will replace these assembled tanks with the welded tanks, and these measures should be temporary. But in the process of containing the accident and decommissioning somehow, "temporary" measures tend to be permanently temporary until something bad happens.

Since the radiation here is almost all beta radiation, if workers are required to do this work of applying putty and placing the acrylic sheets on all high-radiation spots, I'm afraid the radiation exposure could be significant, despite several layers of gloves.

TEPCO may be the master of cheap (quasi-)solutions, but that, I'm afraid, is one of the characteristics of the Japanese. I'm sure it is shared by many other peoples in the world, but I've been seeing it repeatedly in the past two and a half years to deal with the nuclear accident and radiation contamination.

Construction of impermeable walls by freezing the soil around the reactor/turbine buildings is to be funded by the national government, but the debate among net citizens is almost all about the cost. There are many, supposedly engineers, who are claiming they can do other methods cheaply and quickly at a fraction of the cost of frozen walls.

There was a similar argument when AREVA's co-precipitation decontamination system and Kurion's cesium absorption system were first adopted soon after the start of the accident in March 2011. Many Japanese people, scientists, engineers and media questioned why the Japanese government was paying foreign companies a ton of money, and grumbled that an all-Japan team of companies like Hitachi, Toshiba with the help from Japanese scientists and engineers could do the same thing much better and much much cheaper.

Hitachi and Toshiba later delivered such systems. Hitachi built the Reverse Osmosis Apparatus that leaked high-beta water to the ocean (March 2012). Toshiba built SARRY, which is just as reliable as Kurion and prone to unexpected stoppage and leaks including pinhole leak from corrosion caused by the bad weld.

Price tags do not indicate the superiority or inferiority of technologies, of course.

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RO Waste Water Leak at #Fukushima I Nuke Plant: TEPCO Says the Leak May Have Started A Month Ago after Examining Beta-Radiation Exposure of a Worker

I see. TEPCO may not have a water gauge in every 1,000-tonne tank assembled from metal sheets, rivets and rubber packing, but TEPCO has workers as a radiation gauge.

I first learned of this information via the tweets (here's one from @macomelo) from people who either regularly attend TEPCO's press conference or watch the live cast of the press conference.

They said:

• TEPCO knew that the beta radiation exposure of workers had started to rise in July.

• So, TEPCO now thinks the contaminated RO waste water may have been leaking since July.

I found Asahi Shinbun article (8/27/2013) which has more details:

• The information was disclosed by TEPCO at a meeting of NRA's Working Group to deal with contaminated water at Fukushima I Nuclear Power Plant held in the evening of August 27, 2013.

• TEPCO examined the level of beta radiation exposure of a worker who was working at a radio relay station located at about 20 meters from the RO waste tank that leaked, and found that the beta radiation exposure had started to increase in mid July.

• The worker worked at the radio relay station for about 2.5 hours per day.

• TEPCO will examine the data for the previous months.

• TEPCO speculates that it was initially a minute leak but the amount gradually increased. There have been occasional rainfalls since mid July with 30 milliliter per day precipitation, and the leaked waste water was spread and absorbed in the soil with the rainfalls.

• NRA instructed TEPCO to conduct survey to determine the cause of the leak, and to dig observation wells in the areas around the leak to determine the spread of radioactive materials.

Many say "TEPCO lied again". I'm more inclined to say TEPCO couldn't connect the dots, as I do not believe any more that TEPCO is smart enough to come up with a lie.

(Or TEPCO dared not connect the dots because it didn't want to know.)

At Nuclear Regulatory Authority's site, there is a TEPCO document that contains charts that plot beta radiation exposure of workers who do the tank patrol, and of the worker who worked at the radio relay station (English labels are by me):

Location of the radio relay station (in red square) and the tank that leaked (No.5 in red circle, notation is mine):

The area where the relay station is located has been found with high beta radiation, up to 95.55 millisieverts/hour at 70-micrometer equivalent dose (to express the effect on skin and the crystalline lens (of the eye)).

TEPCO is being heavily criticized for "skimping" on the tank patrol by not assigning enough workers for the patrol and not doing the patrol long enough. After looking at the spikes August 19 in beta radiation exposure for workers who were doing the "hasty" patrol, I'm not inclined to blame TEPCO that much.

Maybe Minister of Economy, Trade and Industry and his subordinates can make themselves useful and show TEPCO a proper way by example to carefully examine the tanks daily that contain highly radioactive waste water.

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High Beta Radiation on Floor Surface in Reactor 2 Building at #Fukushima I Nuke Plant

As Toshiba workers splashed strippable paint on the floor at the Truck Bay Door of the Reactor 2 building (southwest corner) and stripped the paint to remove radioactive materials on the floor to lower the radiation for the future work (installing thermocouples), they were mostly removing the radioactive materials emitting beta radiation.

Outside Fukushima I Nuclear Power Plant, if the gamma radiation levels are measured in microsievert/hour in single or double-digit (i.e. 2 microsieverts/hour or 20 microsieverts/hour), they are considered high. The samples of the "black dust (thing, material, plant, dirt, etc.) measure anything from 0.6 microsievert/hour to over 50 microsieverts/hour depending on the locations, usually measuring gamma ray only.

At the entrance of the Reactor 2 building, the radiation levels on the floor are measured in millisieverts/hour. Of the four decon methods tried on the floor, vacuuming and strippable paint were somewhat effective in reducing the gamma radiation. Strippable paint was the most effective in reducing the beta radiation, and wet mopping and vacuuming were somewhat effective. Dry mopping spread the beta contamination, instead of reducing it.

10 millisieverts/hour is 10,000 microsieverts/hour.

I'm waiting to see if TEPCO does the nuclide analysis of the vacuumed dust or stripped paint, but TEPCO being TEPCO I don't have much hope. I'd love to know what kind of radioactivity by what nuclide would cause such high radiation levels.

From TEPCO's Working Group meeting reference material, pages 8 to 18 (I added English labels; 5/28/2012):

All this work is to later install thermocouples in the Containment Vessel, and that will have to be done by human workers. The Truck Bay Door is one of the two ways to get to the possible installation locations (there are two). Near one of the installation location candidates, there is a spot whose surface radiation exceeds 3,000 millisievert/hour (3 sieverts/hour or 3 million microsieverts/hour, take your pick). TEPCO's first choice is to install on top of the TIP Room by entering from the Truck Bay Door (access route 1, in blue). They may not be too keen to do the installation work near 3,000 millisievert/hour location...

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#Fukushima I Nuke Plant Waste Water Leak: TEPCO Insists It Was Only 150 Milliliters That Leaked into the Ocean

12 tonnes of waste water after the reverse osmosis leaked when the Kanaflex hose decoupled, but TEPCO says hardly any of that water reached the ocean. Rejoice.

150 milliliters is 150 cubic centimeters. One liter is 1,000 milliliters, or 1,000 cubic centimeters. 1 tonne is 1,000 liters.

So, TEPCO is telling us only 0.00125% of the waste water leaked into the ocean. OK, then. Where did the water go?

From Jiji Tsushin (4/6/2012):

海に流出「１５０ミリリットル」＝汚染水１２トン漏れ、東電試算－福島第１

TEPCO calculated the amount of the leak into the ocean as "150 milliliters", out of 12 tonnes of waste water that leaked at Fukushima I Nuclear Power Plant

　東京電力福島第１原発の汚染水処理システムで５日未明、配管から推定１２トンの水が漏れた問題で、東電は６日、海への流出は１５０ミリリットル程度にとどまるとの試算を発表した。

TEPCO announced on April 6 that only about 150 milliliters of the 12-tonne waste water that leaked from the pipe in early hours on April 5 from the contaminated water treatment system at Fukushima I Nuclear Power Plant made it to the ocean.

　東電によると、６日午前に１～４号機の南放水口付近の海水を採取し、検査した結果、ベータ線を出す放射性物質の濃度が検出限界値（１ミリリットル当たり０．０１８ベクレル）未満だった。

TEPCO collected samples of seawater at the south water discharge outlet for Reactors 1 through 4 in the morning of April 6 and measured the radioactivity. The result showed the density of beta nuclides was below the detection level (0.018 becquerels/1 milliliter [cubic centimeter]).

　５日午後の検査でも、検出限界値をわずかに上回る０．０２４ベクレルで、松本純一原子力・立地本部長代理は「トン単位で出たら、もっと濃度は高いはず」と主張。汚染水のうち海に流出したのは１５０ミリリットル程度とした。

In the sampling test done in the afternoon of April 5, it was 0.024 becquerels [per 1 millimeter], only slightly above the no-detection level. TEPCO's Matsumoto said the density would be much higher if the leak was in tonnes, and put the amount of the waste water that leaked into the ocean at about 150 milliliters.

Well, considering TEPCO is pouring 23 tonnes of water PER HOUR total into the broken reactors, 12 tonnes may not be much at all, except for concentrated beta nuclides.

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#Fukushima I Nuke Plant: 2 Sieverts/Hr Beta Radiation from Leaked Concentrated Water After Desalination

Gamma radiation was 20 millisieverts/hour. The leak stopped when they tighten the bolt of the tank.

(Ummm... So they are not welded?)

From Nikkei Shinbun (2/3/2012):

東京電力は３日、福島第１原子力発電所の汚染水貯蔵タンクから水漏れし、毎時２千ミリシーベルトの高いベータ線を検出したと発表した。微量で水たまりはできておらず、海への流出もないという。ボルトを増し締めし、漏水は止まった。アクリル板などで遮蔽し、ベータ線は毎時15ミリシーベルトまで下がった。

TEPCO announced on February 3 that the water leaked from one of the contaminated water storage tanks at Fukushima I Nuclear Power Plant. 2,000 millisieverts/hour beta radiation was detected. The amount of the leak was small, and there was no leak into the ocean. The leak stopped when the bolt was further tightened. The radiation was then shielded with acrylic plates, and the beta radiation dropped to 15 millisieverts/hour.

　淡水化装置で濃縮した汚染水の貯蔵タンクの継ぎ手部分の締め付けが緩み、漏水したとみている。水にはストロンチウムが多く含まれるという。直下のコンクリート周辺で、ベータ線のほかにガンマ線も毎時22ミリシーベルトを検出した。遮蔽によって１ミリシーベルトに低下した。

The bolt may have gotten loose at the joint of a storage tank that stores the contaminated water that was condensed by the desalination apparatus (Reverse Osmosis), letting the water leak. TEPCO said a large amount of radioactive strontium might be in the water. On the concrete where the leaked water was, 22 millisieverts/hour gamma ray was also detected in addition to the beta radiation. It dropped to 1 millisievert/hour after shielding.

　経済産業省原子力安全・保安院は３日、水漏れが相次ぎ見つかっていることを重視し、原因究明と再発防止策を報告するよう東電に指示した。

The Nuclear and Industrial Safety Agency instructed TEPCO on February 3 to submit a report on the causes of the leaks at the plant and on the measures to be taken to prevent the leaks from occurring again.

Here's the tank that leaked, and there are 100 more such tanks, from TEPCO (2/3/2012):

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Report from Fukushima (1) Minami Soma: 41.72 Microsieverts/Hr, γ+β+α Radiation Combined in a Municipal Apartment Complex

People live in that complex, including children. The city wants all residents to return to Minami Soma City now that the accident is officially "over".

Minami Soma City Mayor Katsunobu Sakurai became world-famous with his plea for help on Youtube in the early days of the crisis. At that time, not many people were even aware of the nuclear disaster that was progressing, but instead was focused only on the aftermath of the March 11 earthquake and tsunami.

Even after the extent of the radiation contamination resulting from the Fukushima I Nuke Plant accident became known, many cities inside Fukushima including Minami Soma continue to tell their residents that everything is under control, as if the nuke accident were a distant, inconvenient event. Minami Soma has been more realistic, or more aware, than others, as the city does provide more thorough testing of residents for radiation exposure and carries out "decontamination" of residences and public buildings from early on with the help from Professor Kodama of Tokyo University.

But something stopped adding up for me for Minami Soma, slowly over time. Why does the mayor and city officials insist on the residents to return? Why do they insist on "decontamination" even when they know it doesn't quite work (they have the measurement data of before and after)? Why do they punish the more unfortunate residents who lost their homes in the quake and tsunami by cutting off their public assistance and taxing the donation money they received?

With citizens' distrust of the government of all forms and sizes perhaps all-time high, as the Canadian Medical Association Journal article correctly points out, more people in Fukushima are starting to speak out openly about their situation, mostly in blogs. I have three of these I've just happened to read today, though I'm sure there are more others.

The first one is the blog titled "Night that never ends (消えない夜)", written by a man in Fukushima Prefecture. So he says, and looking through his posts I don't have a reason to doubt it.

In the post titled "Truth of Minami Soma City" on December 20, he reports the results of his radiation survey he conducted using his several personal survey meters at a public housing complex in part of Minami Soma City that was designated as "evacuation-ready zone", where the residents were supposed to evacuate at a moment's notice in case of a nuclear emergency, and where children and pregnant women "were not supposed to be there" (but they were, as there was no support from the city to evacuate).

From "Truth of Minami Soma City" post, at "Night that never ends" blog (12/20/2011):

Instead of words, photos are the best for people to see the fact.

The photos will be the irrefutable evidence.
Haramachi District of Minami Soma City in Fukushima Prefecture. It was once designated as "evacuation-ready zone" [since abolished, on September 30].

These are the photos taken today, December 20, 2011, at the municipal housing complex in Kita Nagano in Haramachi District.

I am asking the blogger if I can use his photos. While I wait for the answer (he has said no to other people), you can go to his post and view them. The information he gives in the post is the following:

People have lived in the complex since March 11, as the "evacuation-ready zone" does not require evacuation unless it is an nuclear emergency. According to the blog, most of the children have evacuated but there are several who have remained.

Radiation on the pavement just outside one of the apartment building.

• Gamma radiation: 10.83 microsieverts/hour

• Beta and Gamma radiation: 14 microsieverts/hour

• Alpha, beta and gamma radiation: 41.72 microsieverts/hour

Toward the end, he writes:

しかも住民が知らない数値だった。
高いとは思って居たが、これほど高いとは思わず避難先から週末に子供達が帰って来た時に外で遊ばせていたそうだ！
どこを測定しても高い放射線量が確認された。

The residents never expected to see these kind of numbers.
They thought the radiation levels could be high, but never suspected they were this high. When their children came back for the weekend, they told me they let the children play outside.
Everywhere I measured, the radiation was high.

これが南相馬市営の住宅で南相馬市の真実である！

This is the municipal housing run by Minami Soma City. This is the truth of Minami Soma City.

ここはﾁｪﾙﾉﾌﾞｲﾘか？
と錯覚する…

Is this Chernobyl?
I wonder.

He says he has informed the city government about the high radiation in the complex. Looking at the map, it is in the high radiation area in Minami Soma City where the city is going to reopen 2 elementary schools and one junior high school next February, now that the nuke plant has achieved "cold shutdown state" and "evacuation-ready zone" is no more.

What's even sadder, if it's true, is that these schools will reopen at the requests from the parents.

What's so important about sending their kids to school in an area that has over 40 microsieverts/hour total radiation?

"Night that never ends" - what a great title.

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AP Artricle on Fuku-I 45-Tonne Water Leak (No Mention of Strontium)

AP decided to focus only on relatively small numbers for radioactive cesium in the 45 tonnes of water that was found leaking from the evaporative condensation apparatus at Fukushima I Nuclear Power Plant on Sunday.

No mention of strontium, 100,000 becquerels/cubic centimeter or 100 million becquerels/liter, anywhere.

From AP via Washington Post (12/5/2011):

TOKYO — Japan’s crippled nuclear power plant leaked about 45 tons of highly radioactive water from a purification device over the weekend, its operator said, and some may have drained into the ocean.

The leak is a reminder of the difficulties facing Tokyo Electric Power Co. as it tries to meet its goal of bringing the tsunami-damaged Fukushima Dai-ichi nuclear power plant to a cold shutdown by year’s end.

pool of radioactive water was discovered midday Sunday around a decontamination device, TEPCO said in a statement on its website. After the equipment was turned off, the leak appeared to stop. Later, workers found a crack in a concrete barrier leaking the contaminated water into a gutter that leads to the ocean.

TEPCO estimated about 300 liters leaked out before the crack was blocked with sandbags.

Officials were checking whether any water had reached the nearby ocean.

The leakage of radioactive water from the Fukushima plant into the Pacific Ocean in the weeks after the March 11 accident caused widespread concern that seafood in the coastal waters would be contaminated.

The pooled water around the purification device was measured Sunday at 16,000 bequerels per liter of cesium-134, and 29,000 bequerels per liter of cesium-137, TEPCO said. That’s 270 times and 322 times higher, respectively, than government safety limits, according to the Citizens’ Nuclear Information Center in Tokyo.

Cesium-137 is dangerous because it can last for decades in the environment, releasing cancer-causing radiation. The half-life of cesium-134 is about two years, while the half-life of cesium-137 is about 30 years.

TEPCO is using the purification devices to decontaminate water that has been cooling the reactors. Three of the plant’s reactor cores mostly melted down when the March 11 tsunami knocked out the plant’s cooling system.

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#Fukushima I Nuke Plant: 45 Tonnes of Treated Water May Have Leaked to the Ocean

While that may not much (45 tonnes), the water may contain extremely high levels of beta-nuclides like strontium; according to TEPCO, the density of strontium could be as high as 100,000 becquerels per cubic centimeter. That's 100 million becquerels per liter.

The leak was found at the post-Kurion/SARRY treatment facility that condenses the treated water (TEPCO calls it "evaporative condensation apparatus).

Here's TEPCO's handout for the press on December 4, 2011.

Here's from Yomiuri Shinbun (12/4/2011; since I'm at the terminal in the public library I cannot quote the original Japanese as it won't allow copying. But Yomiuri Shinbun tends to retain the link for a long time):

TEPCO announced on December 4 that about 45 tonnes of contaminated water leaked at the water treatment facility at Fukushima I Nuclear Power Plant and part of the water has leaked outside the facility.

The water may have gone into the drains and leaked into the ocean, according to TEPCO, but "It would be a small amount even if the water had leaked, and very little effect [on marine life]", says the company.

The leak was found at the evaporative condensation facility, which the water goes after being treated to remove radioactive cesium [Kurion and SARRY]. The leaked water is 5 centimeter deep inside the facility. On the surface of the water, the radiation level measuring gamma rays is 1.8 millisievert/hr, but it is 110 millisieverts/hr measuring beta rays. In order to mop up the water in the facility, the workers would have to do it without coming in contact with the water to avoid exposure to beta-ray radiation.

According to TEPCO, 100,000 becquerels/cubic centimeter of strontium, a beta nuclide, may be in the water. The level is 100,000 to 1 million times the safety limit for seawater.

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