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NAIIC report: Fukushima manmade; minor loca due to earthquake

Nuclear Monitor Issue: 
WISE Amsterdam

Early July the National Diet of Japan published the official report of the Fukushima Nuclear Accident Independent Investigation Commission (NAIIC). The report states that although triggered by the earthquake and tsunami, the March 11, 2011 accident at the Fukushima Daiichi nuclear power plant cannot be regarded as a natural disaster but a "profoundly manmade disaster". Evidence that the reactors were severely damaged before the tsunami hit the coast is mounting.

"The earthquake and tsunami of March 11, 2011 were natural disasters of a mag-nitude that shocked the entire world. Although triggered by these cataclysmic events, the subsequent accident at the Fukushima Daiichi Nuclear Power Plant cannot be regarded as a natural disaster. It was a profoundly manmade disaster – that could and should have been foreseen and prevented. And its effects could have been mitigated by a more effective human response."  

These are the first lines of the 'Message of the Chairman' in the official report of the Fukushima Nuclear Accident Independent Investigation Commission (NAIIC). On October 30, 2011, the NAIIC Act (officially, the Act regarding Fukushima Nuclear Accident Independent Investigation Commission) was enacted, creating an independent commission to investigate the Fukushima accident with the authority to request documents and request the legislative branch to use its investigative powers to obtain any necessary documents or evidence required. This was the first independent commission created in the history of Japan’s constitutional government.

The report (published early July by National Diet of Japan) reveals several chronic issues and contradicts reports by the Japanese government and Tepco. But as always it was cherrypicking for different players. While the general public opinion said the accidents was 'handmade', the nuclear industry PR did not hesitate to show that it was a 'Japa-nese accident': Japanese culture was the main culprit, implying the causes of the accident were solely Japanese and nuclear power as such has nothing to do with it. In the July 5, World Nuclear News report on the NAIIC-report, is not once mentioned that the earthquake was an important factor in how the ac-cident started: "Japanese culture itself" was the culprit. 

And indeed the collusion between the Japanese government and Tepco is an important factor why the plant was so vulnerable. But that is only partly to blame on 'Japanese culture'. But, as the UK daily The Guardian points out (July 6) by claiming the disaster was 'made in Japan', the official report reinforces, yet does not explain, unhelpful stereotypes. Bringing out the "made in Japan" argument is not helpful. It panders 
to the uniqueness idea and does not explain, but rather reinforces, existing stereotypes. Moreover, the supposedly Japanese qualities that the report outlines, such as obedience, reluctance to question authority, "sticking with the program" and insularity, are not at all unique to Japan, but are universal qualities in all societies. Putting a cultural gloss on the critical investigative report sends a confusing message to the global community particularly when it comes from a country that is a world leader in technological sophistication.

It is almost inherent of the nuclear industry to have close ties with regulators. For instance in the Netherlands, regulating and promoting nuclear power were placed under the same Ministry in 2010. Or, internationally the IAEA's main task is to promote nuclear power ('The Agency shall seek to accelerate and enlarge the contribution of atomic energy') while at the same time monitoring safeguards and enhancing 'standards of safety for protection of health and minimization of danger to life and property'. But even important: it is obvious that nuclear po-wer thrives in countries with exactly that same 'culture': a centralised society, with the tendecy to critize alternative views, suppress dissent, and maintain 'reflexive obedience'; and a government bodies relying too much on assurances and complacency than true oversight. 

Record radiation detected at Fukushima reactor. 
Tepco said record amounts of radiation had been detected in the basement of
reactor number 1 on June 28, further hampering clean-up operations. Tepco took samples from the basement after lowering a camera and surveying instruments through a drain hole in the basement ceiling. Radiation levels above radioactive water in the basement reached up to 10,300 millisievert an hour, a dose that will kill humans within a short time after making them sick within minutes. The annual allowed dose for workers at the stricken site is reached in only 20 seconds.
AFP, 28 June 2012

LOCA result of earthquake
Another finding, not frequently mentioned in headlines, and contrary to all previous statements by Tepco and the Japanese government is the fact that the Fukushima-reactors were already severely damaged after the earthquake and before the tsunami hit the Japanese east-coast. A Loss-Of-Coolant-Accident (LOCA) was in progress. The Nuclear Monitor published about it several times (for the first time in the May 27, 2011 issue), but now the official report confirms this. What is important to realise (and what the NAIIC-report –or at least the executive English summary- fails to mention) is that although the earthquake was 9.0 magnitude, the epicentre was 110 miles (172 km) out at sea.

The accident is clearly attributable to the natural phenomena: the earthquake and resulting tsunami. Yet a number of important factors relating to how the accident actually evolved remain unknown, mainly because much of the critical equipment and piping relevant to the accident are inside the reactor con-tainment facility and are thus beyond the reach of inspection or verification for many years to come.

In spite of this, Tepco specified in its interim investigation report that equipment providing key safety features was not damaged by the earthquake, and that the main cause of the accident was the tsunami. Included in the report was a disclaimer that the report is based on findings “to the extent confirmed.” The government also wrote a similar accident report that was submitted to the International Atomic Energy Agency (IAEA).

However, the report states, "it is impossible to limit the direct cause of the accident to the tsunami without substantive evidence." The Commission believes that this is an attempt by Tepco to avoid responsibility by putting all the blame on the unexpected (the tsunami), as Tepco wrote in their midterm report, and not on the more foreseeable earthquake.

Although there were a number of external power lines to the plant, there were only two source stations, and both were put out of commission by the earthquake, resulting in a loss of external power to all the units. The diesel generators and other internal power equipment, including the power distribution buses, were all located within or nearby the plant, and were inundated by the tsuna-mi that struck soon after. The assumptions about a normal station blackout (SBO) did not include the loss of DC power, yet this is exactly what occurred. (DC is the abbreviation for 'direct cur-rent', which is a type of electrical current that travels through a circuit in only one direction. AC stands for 'alternating current', which is an electrical current that frequently reverses direction.)

Investigate and verify causes
The Commission conducted its investigations and hearings carefully, 'conscious of not jumping to conclusions based on preordained policy'. The Commission recognizes the need for the regulators and Tepco to investigate and verify causes of the accident based on the following facts: 

  1. The emergency shut-down feature, or SCRAM (Rapid shutdown of a nuclear reactor where fission is halted by inserting control rods into the core), went into operation at Units 1, 2 and 3 immediately after the commencement of the seismic activity. Strong tremors at the facility began 30 seconds after the SCRAM and the plant shook hard for more than 50 seconds. That does not mean, however, that the nuclear reactors were incapable of being impacted by the seismic movements. It is thought that the ground motion from the earthquake was strong enough to cause damage to some key safety features, because seismic backchecks against the earthquake design basis and anti-seismic reinforcement had not been done.
  2. The reactor pressure and water levels make it obvious that a massive loss of coolant (LOCA) did not occur in the time period between the earthquake and the tsunami. However -as has been published by the Japan Nuclear Energy Safety Organization (JNES) in the “Tech-nical Findings” composed by NISA- a minor LOCA, from a crack in the piping and a subsequent leak of coolant would not affect the water level or pressure of a reactor, and could have occurred without being apparent to operators. If this kind of minor LOCA were to remain uncontrolled for 10 hours, tens of tons of coolant would be lost and lead to core damage or core melt.
  3. The government-run investigation committee’s interim report, NISA’s “Technical Findings,” and specifically Tepco’s interim report, all concluded that the loss of emergency AC power -that definitely impacted the progres-sion of the accident- “was caused by the flooding from the tsunami.” Tepco’s report says the first wave of the tsunami reached the site at 15:27 and the second at 15:35. However, these are the times when the wave gauge set 1.5km offshore detected the waves, not the times of when the tsunami hit the plant. This suggests that at least the loss of emergency power supply A at Unit 1 might not have been caused by flooding. Based on this, some basic questions need to be logically explained before making a final determination that flooding was the cause of the station blackout.
  4. Several Tepco vendor workers who were working on the fourth floor of the nuclear reactor building at Unit 1 at the time of the earthquake witnessed a wa-ter leak on the same floor, which houses two large tanks for the isolation conden-ser (IC) and the piping for IC. The Com-mission believes that this was not due to water sloshing out of the spent fuel pool on the fifth floor. However, since we cannot go inside the facility and per-form an on-site inspection, the source of the water remains unconfirmed. 
  5. The isolation condensers (A and B2 systems) of Unit 1 were shut down automatically at 14:52, but the operator of Unit 1 manually stopped both IC systems 11 minutes later. TEPCO has consistently maintained that the explanation for the manual suspension was that “it was judged that the per hour reactor coolant temperature excursion rate could not be kept within 55 degrees (Celsius), which is the benchmark provided by the operational manual.” The government led investigation report, as well as the government’s report to IAEA, states the same reason. However, according to several workers involved in the manual suspension of IC who responded to our investigation, they stopped IC to check whether coolant was leaking from IC and other pipes because the reactor pressure was falling rapidly. While the operator’s explanations are reasonable and appropriate, TEPCO’s explanation is irrational.
  6. There is no evidence that the safety relief (SR) valve was opened at Unit 1, though this should have taken place in the case of an accident. (Such records are available for Units 2 and 3.) We found that the sound of the SR valve opening for Unit 2 was heard at the Central Control Room and at Unit 2, but no one working at Unit 1 heard the sound of the Unit 1 SR valve opening. It is therefore a possibility that the SR valve might not have worked in Unit 1. In this case, a minor LOCA caused by the seismic motion could have taken place in Unit 1.

In short: The damage to Unit 1 was caused not only by the tsunami but also by the earthquake, a conclusion made after considering the facts that: 1) the largest tremor hit after the automatic shutdown; 2) JNES confirmed the possibility of a small-scale LOCA; 3) the Unit 1 operators were concerned about leakage of coolant from the valve, and 4) the safety relief valve was not operating.
Additionally, there were two causes for the loss of external power, both earthquake-related: there was no diver-sity or independence in the earthquake-resistant external power systems, and the Shin-Fukushima transformer station was not earthquake resistant.

Development of civil society
The 'Message of the chairman' in the report ends with a message for change: "The consequences of negligence at Fukushima stand out as catastrophic, but the mindset that supported it can be found across Japan. In recognizing that fact, each of us should reflect on our responsibility as individuals in a democratic society. As the first investigative commission to be empowered by the legislature and independent of the bureaucracy, we hope this initiative can contribute to the development of Japan’s civil society."
Well, despite the hundred of thousand protesting the restart of nuclear reactors and trying to build a civil society, Japanese government gave the permission for the restart of the Ohi-reactors. That decision denied the fact that all ele-ments of this catastrophe are still present in Japanese society: the tendency of relying too much on assurances and complacency than true oversight (as in many societies) as well as the chance of earthquakes.

The executive summary of the NAIIC-report is available at:
Contact: Citizens' Nuclear Information Center (CNIC), Akebonobashi Co-op, 2F-B, 8-5, Sumiyoshi-chp, Shinjuku-ku, Tokyo, 162-0065, Japan.
Tel: +81-3-3357-3800
Email: cnic[at]