June 6, 2018 [with some additions in August 2018]
Releasing Fukushima Daiichi Nuclear Power Station Tritium to the Ocean– Getting the Issues Straight –Citizens' Commission on Nuclear Energy (CCNE)
Representative, Working Group on Safety Regulation of Nuclear Facilities, Tetsuro Tsutsui
1. Recent moves
Large amounts of radcontaminated water have been generated at the Fukushima Daiichi Nuclear
Power Station (FDNPS) site by the mixing of fuel debris cooling water and groundwater flowing into
the reactor and turbine buildings. This contaminated water is passed through radionuclides removal
systems and stored in makeshift tanks as “treated water,” which contains the non-removable tritium[plus other residual radionuclides]. In the last seven years, the accumulated total of this “treatedwater” has surpassed the one million cubic meter mark1 and the 1,000 m3 tanks stand like a forest on
the FDNPS site. As a result, it is reported that in just over three more years there will be no moreland available for putting more tanks.2 Thus the authorities involved have begun to scramble aroundto create a public-acceptance atmosphere for ocean release of this “treated water.”At the same time, this problem is one that was known about at an early stage, with the government(Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) establishing a
Tritiated Water Task Force under the Committee on Countermeasures for Contaminated Water
Treatment. The Task Force released “Tritiated Water Task Force Report” in June 2016.3
At the end of 2017, Chairman Fuketa of the Nuclear Regulation Authority, having said at a
meeting for an exchange of views with Fukushima Prefecture municipalities that there was noscientific problem with the ocean release of the treated water, stated his view that TEPCO shouldmake the decision on the discharge method within the year.4 Furthermore, at the regular press
conference on January 17, he indicated his concern that “the decommissioning of Fukushima Daiichi
reactors would come to a standstill” if the decision on the release was to be further postponed.5
The result of a joint Asahi Shimbun and Fukushima Broadcasting Co., Ltd. public opinion poll
conducted by telephone with respect to residents of Fukushima Prefecture on February 24 and 25 thisyear was that “when asked whether or not they agreed with the release of diluted treated water(accumulated in tanks on the FDNPS site) into the sea, those opposed outnumbered those in favor by
67% to 19%.”6
2. Who is responsible for the decision?
In the first place, it has not been clearly determined, in organizational terms, who is responsible
for the decisions on work guidelines for the cleanup in the aftermath of the FDNPS accident. The
composition of organizations for giving instructions and providing economic support to the TEPCO
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Fukushima Daiichi Decontamination and Decommissioning Engineering Company consists of theInter-Ministerial Council for Contaminated Water and Decommissioning Issues, the Nuclear Damage
Compensation and Decommissioning Facilitation Corporation and the Nuclear Regulation Authority,
but this is simply piling up one organization on top of another and very hard to understand.7
Quite predictably, it was reported that the TEPCO Chairman Takashi Kawamura and the former
chairman of the Nuclear Regulation Authority, Shunichi Tanaka, engaged in a puerile andunprofessional argument in July of last year.8 Both men made advertising-balloon-type statements,
but appeared to have the intention of avoiding any responsibility for decisions. From the standpointof taxpayers, we would like to demand that there is a clear indication of who is responsible. Without
that, there is no way a forum for serious discussion can be created.
The person in the highest position of responsibility in the TEPCO Fukushima Daiichi
Decontamination and Decommissioning Engineering Company, CDO Naohiro Masuda, in aninterview with the Nihon Keizai Shimbun in March this year, stated, “It has become our common
perception that tritium is not harmful. I would like to begin a dialog with local residents (on thedisposal method).”9 It was reported that “having stated that ‘(Ocean release) is one option,’ Mr.
Masuda reemphasized that ‘I will take responsibility for realizing this in line with the government’s
decision.’” From the way the article was written, it appears that there is an awareness that it is thegovernment who is responsible for making the policy decision. Just in the same way as the TEPCO
Chairman Kawamura and the former chairman of the Nuclear Regulation Authority Mr. Tanaka
engaged in their argument last summer, each insisting that the other should make the decision, CDO
Masuda and Chairman Fuketa are recently engaging in similar arguments.
3. Various views on toxicity(1) Factors impeding evaluation of the tritium risk
At issue with the tritium water ocean release is bioaccumulation in the ecosystem and the internal
exposure of the general public when they consume materials from this ecosystem. However, for thefollowing reasons, it is considered that there is almost no data available at present.
 In epidemiological studies, the subjects have very often ingested other nuclides at the same time,making it difficult to study the impacts of tritium alone.
 Experiments have been conducted on mice, etc. as an alternative means, but almost all of thesestudies have used high-dose exposures.10


There is no data that clearly explains the degree of impact of tritium on living organisms.

(2) The view that considers there is no need to be concerned about the effect on the human body
The notion that there is no problem as long as the tritium is released after diluting to the regulatory
standard concentration is as shown below.
Additionally, the concentration level at which it is necessary to report an ocean release is 60,000
Bq/L, and naturally the government and power plant operator premise the diluted release on this2

condition.
a. Ministry of Health, Labour and Welfare11
 It is considered that since tritium exists as water in seawater, even if it is ingested byhumans or fish and shellfish, etc. it will be rapidly excreted and does not (bio)accumulate.
 Impacts of tritium on living organisms are very small, being about one-thousandth of thatof radioactive cesium, which is used as the standard for radioactive substances in food.
 As far as can be seen from the results of measurements of the seawater carried out thus far
in the waters around TEPCO’s FDNPS, there is no cause for concern about the effects oftritium on marine products distributed to the market.
b. Shunichi Hisamatsu (Head of the Department of Radioecology, Institute for Environmental
Sciences, Rokkasho, Aomori)12
There are no reports thus far of serious health effects (from the release of tritium into the sea)
from any country.
c. Japan Nuclear Fuel Limited13
Supposing 18,000 terabecquerels are released into the ocean each year, local fishermen go out
fishing every day and eating the marine products, and even if one keeps staying for the wholeyear around the release outlet, the annual exposure dose would be 0.022 mSv, which is lower
than the annual 1 mSv dose from the natural environment in Japan.
(3) Opinions expressing concern about the effects on the human bodya. Chihiro Kamisawa14
There are concerns about internal exposure from internal ingestion. When tritium is taken into
the human body as tritium water, a part of that is incorporated into cell nuclei, and there is apossibility that it will replace hydrogen atoms that make up DNA (genes). In this case, the low
energy level and the short distance of penetration of the beta radiation released by tritium isextremely effective at damaging genes and there is research that indicates that the dangers of
this should be seen as greater than gamma radiation. It is thought that this becomes more
serious when the tritium behaves as organic tritium. When tritium is part of an organic
compound, it is considered to be more easily absorbed into the human body, more easily
incorporated into cell nuclei where it may remain for long periods of time.
b.

Toshiyuki Umata (Radioisotope Research Center, University of Occupational andEnvironmental Health)15
The modality of tritium exposure is thought to be low dose and low dose rate internal
exposure, but tritium water taken into the body orally, by inhalation, or by absorption throughthe skin is thought to have impacts that are not insignificant due to an even distribution
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throughout the body. Moreover, tritium taken into organic bonds accumulates in the form of
the body’s biomolecules, and as these result in long-term exposure it is important to take thechemical form of the tritium in the body into account.
c.

Junichi Kowaka (Editor of Food and Safety in Daily Life)16
When tritium is taken into cells, and, furthermore, enters the nucleus, as it approaches closer
to the DNA, in the same way as radioactive cesium and strontium, it attacks the DNA.
(Tritium emits radiation to become helium; the part of the DNA which has changed to heliumis then broken and the gene with then “malfunction.” Since this malfunction adds to otherexisting risks, the rate of occurrence of cancer becomes higher with tritium.

(4) Tritium ingestion standard17
Japan has no standards for tritium in drinking water. However it has been pointed out that as aresult of a lack of regulation, 60,000 Bq/L is the default standard for drinking water.18 There is awide range of standards issued by regulatory agencies around the world, with WHO at 10,000 Bq/L,
Canada at 7,000 Bq/L (Ontario Drinking Water Advisory Council recommends 20 Bq/L)19, USA at
740 Bq/L and the EU at 100 Bq/L.
4. Cases of the handling of tritium in Japan and overseas20
As shown in the previous section, there is no accepted theory – each country has taken a prudent
stance toward tritium, as shown below.
(1) The case of the Three Mile Island nuclear accident
In the Three Mile Island accident, roughly 2.43×1013 Bq of tritium (approximately 8,700 m3) was
disposed of by steam release to the atmosphere.
(2) The case of France
The annual releases of tritium from the La Hague reprocessing plant are roughly 1.2×1016 Bq ofliquid and roughly 7.0×1013 Bq of gas. As the necessity for an evaluation of organic tritium
within France was pointed out, the Nuclear Safety Authority (ASN) produced a report known as
the “Tritium White Paper” in 2010. Subsequently, the nuclear facilities operators have preparedand published regular reports.
(3) The case of the UK
The EU fusion experimental reactor JET at the Culham Centre for Fusion Energy (CCFE) burns
deuterium and tritium. It has a system which recovers tritium from cooling water, etc. that
contains a high concentration of tritium, using methods such as electrolysis, cryogenic separation,etc.
45. Options for the handling of tritium water and their evaluation(1) Tritiated Water Task Force Report
Broadly divided, the Task Force Report mentioned above gives the following five kinds ofdisposal methods along with their concept designs and approximate cost estimates. The most
severe conditions are an original concentration of 4.2 million Bq/L, a treatment speed of 400
m3/day and an original amount of 800,000 m3 (to compare the evaluations below for the case of
one million m3 of tritium water, the evaluations are increased by roughly 25%).
--

Injection into geological strata: (in the case of injection following dilution)
For just the injection cost, if surveys for injection wells were to be carried out for about 20
locations, this would require around 620 billion yen, but the long-term monitoring cost is
unknown (new R&D would be necessary)
Ocean release: (in the case of ocean release following dilution)
Around 3.4 billion yen
Steam release: (steam release without pre-treatment)
Around 34.9 billion yen
Hydrogen release: (hydrogen release without pre-treatment)
Around 100 billion yen
Subsurface burial: (deep subsurface burial without pre-treatment)
Around 253.3 billion yen(2) Report of the Japan Center for Economic Research
The Japan Center for Economic Research has released a report entitled “The Fear that the
Accident Cleanup will Cost 50 to 70 Trillion Yen”.21
The report presents two trial calculations for the cost of the disposal of tritium water.
- Disposal of the stored tritium water at a unit cost of 20 million yen/m3 would amount to 20
trillion yen. The report does not give details of any process specifications.
- In the case that all the tritium water is disposed of by ocean release, the cost is not given as it
is small. However, 300 billion yen is allocated for compensation for ‘harmful rumors’(consume caution regarding consumption of marine products from the area) over a period of
40 years. The calculation is based on giving compensation of ten million yen per year to eachof 1500 people related to the Fukushima fishermen’s association in the first year, which is
reduced each year until it reaches zero in 40 years’ time.
(3) Citizens’ Commission on Nuclear Energy Report
The authors, the Citizens’ Commission on Nuclear Energy (CCNE) have issued a Special Report 1
entitled “Settlement After 100+ years of Shielded Isolation” (revised edition, 2017).22
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The report proposes that since at present there are various theories about the hazardous effects oftritium, ocean release not be forcibly implemented but the tritium be stored permanently in tanks
until the dangers of tritium have been fully examined.
Specifically, ten 100,000-ton large-scale tanks, of the kind currently being used in the national oil
reserve base, should be constructed and the tritium water stored for 123 years, when it is expectedthat the radiation will have decayed to one-thousandth of its current value. Thus it is proposed thatthe tritium be managed in this way in order to wait till the radiation has sufficiently decayed. To
implement an inspection by opening the tanks and removing the tritium water about once every 20
years, if one extra tank is constructed, at a unit cost of three billion yen per tank, 11 tanks would cost
33 billion yen, which is very similar to the 34.5 billion yen paid for the frozen barrier around the
FDNPS buildings. Moreover, the design specifications could apply tried and tested methods alreadyused in the national oil reserve base, such as constructing a retention dike around the facility toprovide against accidents. If a further degree of decay is required, more storage tanks of a similar
specification can be constructed to replace those whose lifetime has expired, following which thetritium water is stored in the tanks for a further 123 years, during which time the radiation can be
expected to have decayed a further order of one-thousandth.
Let us consider around how much, when compared with amounts of tritium released when FDNPS
was operating normally, is represented by the current amount of stored tritium if it is managed for
123 years.
a. Accumulated volume of tritium in tanks
As of March 24, 2016, the accumulated amount of tritium in the water stored in the tanks wasroughly 7.6E+14 Bq.23 If this is reduced to one-thousandth, the amount is around 7.6E+11 Bq.
b. Annual amount released to the ocean before the accident24
Prior to the accident, during fiscal years (FY) 2002 to 2009, the actual annual amount released
to the ocean from FDNPS reactor units 1 to 6 (all the units at the site) was 7.8E+11 to 2.6E+12
Bq, or an annual average of 1.5E+12 Bq.
From this result, it can be expected that the amount of tritium would be less than the minimum
actual annual amount that was released to the ocean in the period FY2002 to FY2009.
Regarding safety measures against earthquakes, the construction of a retention dike would be
realistic, using existing tried and trusted methods to prevent any possible leaks. It is thought that it
would be possible to utilize the proposed construction site for FDNPS reactor units 7 and 8 toconstruct this large-scale tank facility. In addition, since these large-scale tanks use space much more
efficiently, their volume stored per unit area of land required is much higher than the 1,000-ton tanks
currently being used on the FDNPS site and it is thought that if the construction of the new tanks
were implemented in parallel with the removal of the current tanks, the new tanks could beconstructed on the area covered by the existing tanks.
Furthermore, what currently known as “tritium water” has been passed through water treatment
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radioactive substance removal apparatuses to remove the radioactivity due to other nuclides, but theauthors have no information as to whether or not these have been 100% completely removed or not.
If there are uncertain factors regarding this point, there would surely be no loss from waiting for theradioactivity of these other nuclides to decay.
6. Conclusion
The toxicity of radioactive substances is not yet fully understood. That is also true of harm fromtritium. Rather than disperse toxic materials into the environment, the fundamental lesson learned
from many years of the country’s serious industrial pollution is that toxic materials should becentrally managed and released into the environment only after they have lost their toxicity. The
CCNE proposal outlined in (3) above is technologically and economically viable, using well-provenengineering at the current industrial level, and is the most stable and safe solution of all those
proposed.
As stated at the outset, in the present situation, where an opinion poll has shown that 67% of
Fukushima residents are opposed to ocean release, it is morally reprehensible that a unilateraldecision to discharge radioactive water into the ocean be taken by those who are responsible andliable for the nuclear accident, the government and TEPCO.

Endnotes: (All in Japanese except when indicated with an asterisk *)1. 1.11 million m3 as of April 2018. “Purification treatment of contaminated water,” TEPCO website:
http://www.tepco.co.jp/decommision/planaction/alps/index-j.html
2. “Treated contaminated water – time for a decision draws near,” Nihon Keizai Shimbun, February 23, 2018
3. Tritiated Water Task Force Report, June 2016:
http://www.meti.go.jp/earthquake/nuclear/osensuitaisaku/committtee/tritium_tusk/pdf/160603_01.pdf (Japanese)
http://www.meti.go.jp/english/earthquake/nuclear/decommissioning/pdf/20160915_01a.pdf (English)
With explanations: “Regarding the Tritiated Water Task Force Report,” November 11, 2016, and others:
http://www.meti.go.jp/earthquake/nuclear/osensuitaisaku/committtee/takakusyu/pdf/001_03_00.pdf
4. “TEPCO urged to discharge or dispose of treated water,” Denki Shimbun, January 16, 2018
5. “Judgment required for release of Fukushima Daiichi treated water,” Denki Shimbun, January 18, 2018
6. “66%‘feel anxious’about radioactive substances - Fukushima Prefecture poll,” Asahi Shimbun, March 3, 2018
7. “Our Path to a Nuclear-Free Japan 2017”, p.97

http://www.ccnejapan.com/?page_id=8000

Tetsuro Tsutsui, “Delay in ‘the government coming the forefront’: Disorderly establishment of organizations
obstructs contaminated water treatment,” Kagaku, Vol.83 No.11 (2013) p.1203
8. “TEPCO Chairman, ‘We are making a judgment on the ocean release of the treated water’,” Nihon Keizai
Shimbun, July 19, 2017
“Repercussions from the TEPCO chairman’s statement – backlash from fishermen and regulatory commission on
release of treated water,” Nihon Keizai Shimbun, July 21, 2017
9. “Treated water release: ‘Dialog with local residents’,” Nihon Keizai Shimbun, March 5, 20187

10. Toshiyuki Umada, Megumi Sasatani, Akira Tachibana, “Evaluation of Impacts of Tritium on Living Organisms,”
Journal of Plasma and Fusion Research, Vol.88, No.3 March 2012
11. “Frequently asked questions,” Ministry of Health, Labour and Welfare website
12. “Removing radioactive substances from contaminated water,” Sankei Shimbun, September 23, 2013
13. “Tritium removal difficult,” Nihon Keizai Shimbun, September 8, 2013
14. Chihiro Kamisawa, “The Tritium Contaminated Water at Fukushima Daiichi Nuclear Power Station,” Kagaku,
Vol.83, No.5 (2013) p.505
15. “Evaluation of Impacts of Tritium on Living Organisms,” Magazine of the University of Occupational andEnvironmental Health, Vol.31, No.1 (2017) p.25
16. “Don’t release tritium (tritiated hydrogen) contaminated water – steam is also frightening!” Food and Safety in
Daily Life, No.275, March 1 (2012) p.5
17. *Canadian Nuclear Safety Commission, “Tritium in Drinking Water,” August 20, 2009http://nuclearsafety.gc.ca/eng/resources/health/tritium/tritium-in-drinking-water.cfm
18. Masako Sawai, “Current State of Fukushima Daiichi Nuclear Power Station,” Medical Treatment for Workers
and Residents, February 2018, p.11
19. *“Report and Advice on the Ontario Drinking Water Quality Standard for Tritium,” May 21, 2009
20. Tritiated Water Task Force Report, p.6 (See Endnote 3)
21. “Future of Energy and Environmental Choices (Extra Editoin) – Public Financial Burden of the Fukushima
Nuclear Accident,” March 7, 201722. Published on November 11, 2017, p.7

http://www.ccnejapan.com/?p=7900

23. Tritiated Water Task Force Report, p.5 (See Endnote 3)
24. Japan Nuclear Energy Safety Organization, “Yearbook of Nuclear Energy Facility Operation and Management,”
2012 Edition, p.608 http://www.inaco.co.jp/isaac/shiryo/pdf/genpatu/jnes_24.pdf

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