Fault lines in Japanese nuclear regime

30 December 2011

The Japanese government's response as the Fukushima nuclear accident developed saw flawed organisation and communication, while the site was inadequately prepared and operators made mistakes.

The conclusions come from an interim report from the investigation committee on the crises at the Fukushima Daiichi and Daiini nuclear power plants after the 11 March earthquake and tsunami. A provisional English translation of the executive summary explained how government agencies were meant to have interacted and cases in which this broke down. It also explained some operational mistakes made by Tokyo Electric Power Company (Tepco) during the accident sequence.

Emergency centres

Japanese law requires the quick establishment of a local nuclear emergency headquarters in the vicinity of the affected site. For Fukushima this meant the assembly of key staff at a facility about five kilometres away, but two factors prevented this from working as expected: One was the devastation of the natural disasters that took out communications links while also preventing timely travel and the provision of food and water. The other was the lack of radioactivity filters at the building, which actually made it useless for a serious emergency of the kind that developed at Fukushima Daiichi.

The report noted gravely that the Nuclear and Industrial Safety Agency (NISA) had been recommended in February 2009 to install proper filters at the facility but "did not take concrete steps" to do so. It added that, "It was not assumed that nuclear disasters may strike simultaneously with the outbreak of earthquake."

Another mismatch between the management of nuclear emergencies and natural disasters emerged at the prime minister's office, where the main nuclear emergency headquarters was situated. This top-level group was headed by the prime minister and meant to absorb information passed on from various agencies and departments before making fast, flexible decisions. It was established on the fifth floor of the prime ministers office, while the national response to the earthquake and tsunami were headed from the basement. "When the integrated responses by the entire government set-up are of critical importance, there was insufficient communication," said the interim report.

This communication failure was exacerbated by the lack of "pro-active" information gathering by NISA and the Ministry of Economics Trade and Industry. They were meant to report the latest information from Tepco to the national response headquarters, but did not act to establish proper lines of communication, such as Tepco's effective teleconferencing system. They also failed to send staff to collect information in person in what the report called "a major concern" when considered with the overall failure of the government in communicating with the public.

Regarding the government's public communication, "The following tendency was observed: transmission and public announcement of information on urgent matters were delayed, press releases were withheld, and explanations were kept ambiguous. Whatever the reasons behind this, such tendencies were hardly appropriate, in view of the communication of an emergency."

At the site

Criticism of Tepco came regarding two potential operating mistakes during the accident sequence. The first was misjudgement of the status of unit 1's isolation condensers, which operators thought were working normally, but were later switched off when more information was gained from instrumentation. This action "was not necessarily incorrect," said the report, "but the decision was not properly reported to, or consulted with, the emergency response headquarters."

It was also "quite inappropriate" that Tepco's emergency centre was in possession of information that would have revealed the malfunction of the isolation condensers more quickly, "but they failed to notice." Moves to begin water injection began as soon as the failure of the isolation condensers was realised, meaning that an opportunity was missed to bring in effective cooling more quickly.

At unit 3 operators had been running the high pressure coolant injection (HPCI) system at low speed while the reactor remained at lower pressure. They became concerned about insufficient water injection by the system and decided to turn it off - but before the alternative injection method of seawater injection was ready and before reducing pressure enough for this to work. This move was made by shift operators and a small number of staff at the local emergency headquarters, without advice from managers, whose own report on the matter was also delayed. The report said this caused a delay of about six hours in the onset of seawater injection.

At the same time, operators did not realise the speed that the batteries powering unit 3's HPCI had been depleting. Overall, there was a "lack of recognition of the necessity and urgency of alternative water injection into unit 3."

An overall failing of Tepco, NISA, METI and its predecessors was to fail to plan for very large tsunamis. The site was licensed in the 1960s and 1970s on the basis of a 3.1 metre tsunami wave and although later studies indicated that much larger waves were possible, no concrete steps were taken by any of the bodies to plan for that eventuality. Furthermore, external risks like tsunami and earthquake were not part of a government analysis of measures against severe accident made most recently in 2002 - and the recommendations from that were voluntary and not part of regulatory requirements.

In this context it was noted that Tepco had put in place inadequate measures to cope with station blackouts, and had no plans for the seawater injection technique on which it relied.

Radiation detection systems were noted to have suffered badly in the earthquake. Many monitoring posts lost power or were washed away by the natural disasters, but that was only one aspect of the problems in radiation monitoring. The government "lacked an attitude of making the monitoring data promptly available to the public. Even when some data were made public, it was only partial disclosure."


Japan had established the System for Prediction of Environmental Emergency Dose Information (SPEEDI) for exactly the kind of nuclear emergency presented by the Fukushima accident. Although the earthquake disrupted SPEEDI's operation so that it could not give full results on radiation doses at various places near the accident site, it was still accurately predicting the path of the radioactivity.

Once the local emergency headquarters lost its functionality, said the report, it should have been either NISA or the national headquarters that communicated SPEEDI's results to the local governments and the public. Neither body did this, nor did the competent department - the Ministry of Education, Culture, Sports, Science and Technology - which was not even present in its SPEEDI capacity at the national response headquarters.

As a result, this excellent information was not used by local governments to plan their evacuations. Those bodies were largely left to plan on their own because neither the government or power companies had "tackled fully" the issue of large scale evacuation.


Researched and written
by World Nuclear News