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Home arrow Environment arrow Reflections on the Fukushima Daiichi Nuclear Accident

Level 5

Level 5 in the defense-in-depth concept concerns Offsite Emergency Response.

8.2.3.1 Identified Problems During the Course of Accident

Although overall offsite actions (Emergency Response) helped reduce health risks associated with radiation, many problems have been identified and mentioned in detail, especially in Diet's Investigation Committee's report [3]. The problems include:

• Loss of offsite center's function (coordination of offsite action) due to damage by earthquake to communication line and habitability under radiation environment,

• Confusion and lack of necessary actions due primarily to lack of knowledge and

drills,

• Confusion in the line of command including Prime Minister, Government, and TEPCO.

A different perspective [48] has been presented that, since evacuation significantly degrades quality of life of evacuees and even may lead to physical and mental health problems, the necessity of extended evacuation could be better evaluated (not necessarily at the time of accident but before anything happens) objectively by not singling out risk of radiation but by using multi-criteria decision analysis such as J-value technique developed from a life-quality index.

There is also an argument by some experts that reduction of acute and chronic effects of radiation are not well balanced, and that evacuation was unnecessary beyond 3 km from the NPS to reduce health risk [49]. On the contrary, it increased health risk by forcing evacuees into a stressful life and reportedly even brought about death to more than 60 patients in hospitals. According to the UNSCEAR report on the Fukushima Accident [50] “No discernible increased incidence of radiationrelated health effects are expected among exposed members of the public or their descendants. The most important health effect is on mental and social well-being.”

Recognizing but setting these discussions aside, this Sect. 8.2.3 of the chapter focuses on practical problems that surfaced during the course of the accident in the area of the fifth layer of defense-in-depth.

A report on implementation of the Emergency Plan from the association of municipalities having NPPs [51] provides valuable details of how the Emergency Plan was implemented (or not implemented), what information source local residents depended on in deciding to evacuate, etc.

A Japanese Health Physics Society's (JHPS) report [52] covers comprehensively, based on information including accident investigation reports [2, 3], the issues in Emergency Plan and post-accident health physics issues, including monitoring and ingestion control, computerized projection system, evacuation, radiation protection standards, exposure to the public and its assessment, exposure to the workers and its assessment, and risk communication. It is appropriate to list some of the identified problems raised by JHPS to help consider what causes were behind the issues.

Monitoring and Ingestion Control

• 23 of 24 radiation monitoring posts were rendered unusable due to tsunami (physically lost) and loss of transmission line;

• Mobile survey systems faced difficulties (road, fuel, transmittal of data, etc.);

• Aerial survey was not available (not planned and needed modification of helicopter), while U.S. Department of Energy (DOE)'s “drone” survey started 6 days after the accident;

• Problems of contaminated beef were caused by feeding contaminated rice straw (Government alerted only cattle farmers and not suppliers of rice straw); and

• Management system for monitoring and ingestion control was not fully pre-

planned (procedures and devices).

Computerized Projection System

• Computerized tool was not available or not used, while Emergency Preparedness and Response (EPR) depended on computerized tool (ERSS/SPEEDI) developed by the Government;

• Emergency Response Support System (ERSS) was based on Safety Parameter

Display System (SPDS) data coming from the plant but they were not available due to loss of DC power in the plants;

• SPEEDI (Dose Prediction System) was usable by assuming unit release due to

loss of ERSS, but calculated results were not released from the Government (Cabinet Office staffers) to the public to help their evacuation;

• Calculation using SPEEDI was sent to the prefectural government of

Fukushima after March 12. However, the staffers in the local government did not consider the use of this calculation in EPR. Consequently, out of 86 emails including SPEEDI calculation results they had received, 65 were deleted without sharing even within the organization;

• Simulation of radioactivity diffusion in the ocean was not planned, conse-

quently not available; and

• Even though measurement was done for seawater by taking samples, nothing was done to check the level of radioactivity deposit on the seabed, whereas this deposit led to contaminated fish (flounder, sole, and other fishes according to food chain).

Evacuation

• Offsite center did not function for coordination of offsite activities including evacuation due to loss of communication and insufficient design for radiation protection;

• Local municipality and residents decided on evacuation based on different

sources [3, 51] (Prime Minister's Office, municipality, commercial media);

• Area of evacuation was changed many times as the accident evolved, which forced some evacuees to change place of settlement more than six times (for residents in townships of Namie and Futaba located north, more than 70 % of residents had relocated more than four times) [3];

• Due to lack of information from SPEEDI to local authorities or residents, evacuees headed northwest where the plume was spreading (leeward) on the morning of March 15, when release of radioactivity was largest;

• Questions had already been raised before the accident from experts on the use

of atmospheric diffusion of released radioactivity and subsequent dose prediction system in emergency response. The argument is that basically the basis of precautionary offsite action should be on plant condition rather than measured or predicted dose. The fact is that codes are not technically mature enough (ERSS cannot predict well timing and magnitude of containment failure. SPDS does not necessarily cover all the parameters that describe the plant condition leading to core damage. SPEEDI cannot predict well diffusion under condition of precipitation.)[1];

• There was no drill before the accident assuming that information from ERSS or SPEEDI is unavailable;

• There was no clear pre-plan for the evacuation path and where to settle;

• Residents experienced difficulty living in sheltering zone due to stoppage of incoming food;

• Evacuees considered this to be temporary evacuation, and did not imagine it

would end up becoming de facto relocation;

• Evacuation of hospitalized patients was diffi and ended up in more than 60 deaths. Hospitals were supposed to establish evacuation plan on their own (according to the plan by the local government), but it was revealed they had not; and

• JHPS report raised the role of local government as one of the key points to be

scrutinized in light of the Fukushima case where lack of its capability faced with combined disaster of earthquake, tsunami, and nuclear accident became evident.

Radiation Protection Standards

• There was confusion about taking iodine tablets. Recommendation from NSC was handled by the recipient local governments inappropriately, and local governments did not release orders, while certain municipalities instructed, on their own decision, the taking of iodine tablets.

• There were some cases of denial by hospital staffers to see contaminated evacu-

ees; and

• Standards have been changed by facing reality such as

– Screening level (for decontamination of residents),

– Exposure to school for pupils to play (from 20 to 1 mSv/year), and

– Allowable level of radioactivity in foods.

Risk Communication

• Government frequently used the phrase “no immediate threat,” which was ambiguous. Recipients of this message may think “there is no risk” or may think “not immediate effect but, in the long run, there will be a health effect”;

• There had been cases of delay of disclosure (intended or not) of information or

release of unclear messages from the Government and TEPCO, which fueled distrust from the public;

• According to opinion polls, 70 % of the public distrust information from the

Government;

• Disparity in the level of knowledge between experts and lay people was occasionally completely neglected in communication;

• Delay of notice to neighboring countries on release of slightly contaminated water (3,000 m3) to the ocean, though intended to avoid larger risk of spill-over of heavily contaminated water, invited distrust from them;

• Need for mental health care and for education on risk of low level radiation were raised after the accident; and

• The role played by the Social Media System (SMS) was highlighted in the

Fukushima accident. There were cases of disguised authoritative information sources, which led the public authority to use authentication. TEPCO delayed starting the use of Twitter and heavily used PDF files in release of information, which frustrated the public. Generally speaking, neither the Government nor TEPCO had enough SMS-savvy staffers.

8.2.3.2 Technical Lessons

The following issues need revisiting and changes:

• Delineation of responsibility,

• Command line, coordination,

• Design and function of “offsite center,”

• Offsite emergency plan (zoning, drills, and others), and

• Mental health care of evacuees.

In particular, training of staff members to understand what obtained information or data mean, especially, preparedness for accidents by frequent drills, using realistic scenario and education/training, would improve capability. Amendment of relevant laws by addressing the issue of delineation of responsibility and to increase national capability in emergency response is needed.

Evacuation forces evacuees significant degradation of their quality of life and may lead to physical and mental health problems. Prior careful thinking of the value of evacuation such as by the use of J-value as a tool could have assisted minimization of overall risk associated with the nuclear accident.

8.2.3.3 Possible Cultural Attitude Issue in the Background

The fact that serious “reality drills” and education/training were not in place indicates that those involved were not seriously thinking “an accident can happen here.”

8.2.3.4 Possible Institutional and Societal Issues in the Background

Operators' tendency to assure to local residents that no such accident could happen here to avoid uneasiness with NPS deprived residents of an opportunity for realistic drills involving them.

There is no such organization like U.S. Federal Emergency Management Agency (FEMA) or Nuclear Emergency Planning Delivery Committee (NEPDC), which coordinates activities across different agencies in the Government for concerted actions. The Cabinet's Crisis Management team in the Japanese Government did not function in confronting the nuclear accident. In an environment where ministries and agencies did not communicate with each other very well, coordinated action was difficult.

Education and training of staffers in local and central governments involved in Emergency Response could have enabled them to understand what actions to take and what is the significance of information they had received from experts or Operator.

Although a group of experts was functioning to provide advice to the Cabinet Office and meetings had been held on a daily basis with participation of politicians [6], it is not clear to what extent the recommendations from this group (such as on the use of SPEEDI information) was used in decision-making. There is a similarity with the case of TEPCO in the handling of information from senior advisory groups mentioned relevant to the 4th layer of defense-in-depth.

  • [1] IAEA Safety Standard [53] requires offsite precautionary actions be taken on the basis of conditions at the facilities, before release of radioactive material occurs.
 
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