Collection of Lessons Learned fromthe Fukushima Daiichi Accident

MM 2021

Japan Nuclear Safety Institute
Please consult JANSI before reproducing any part of this publication.

Contents
1. Introduction ....................................................................................................................1
2. Overview .......................................................................................................................3
3. Knowledge ....................................................................................................................4

Knowledge 1. Things that are possible happen. Things that are thought not possible also happen................ 4
Knowledge 2. You cannot see things you do not wish to see. You can see what you wish to see. ................. 6
Knowledge 3. Assume to the extent possible and make full preparations. .......................................................... 7
Knowledge 4. Creating a framework alone does not mean it will function. Frameworks can be constructedbut goals not collectively shared. .................................................................................................... 9
Knowledge 5. Everything changes, respond flexibly to changes. ........................................................................ 11
Knowledge 6. Acknowledge that risks exist, and create a culture in which it is possible to debate the risks
head on. ............................................................................................................................................. 11
Knowledge 7. It is vital to be conscious of the importance of making decisions and taking action while seeing
with your own eyes and thinking with your own head, , and vital to cultivate such faculties. 14
Knowledge 8. Other: Create an environment for employees to respond in an emergency. Make appropriate
public statements and engage in appropriate public relations, and take care also when
responding to overseas inquiries. .................................................................................................. 16

4. Lessons ......................................................................................................................17

Lesson 1-1 (Preconditions, occurrence probability, and establishment of knowledge) (Serial no. 1) ..................... 17
Lesson 1-2 (Learning from incidents and experiences) (Serial no. 2) ..................................................................... 18
Lesson 1-3 (Assess risks logically) (Serial no. 3) ................................................................................................ 19
Lesson 2-1 (Attitude of confronting that which you do not want to see) (Serial no. 4) ............................................. 20
Lesson 2-2 (Development of a system for reducing omissions) (Serial no. 5) ........................................................ 22
Lesson3-1 (Improvement of facility and system reliability) (Serial no. 6) ................................................................. 23
Lesson3-2 (Meticulous formation of facilities in preparation for the worst) (Serial no. 7) ................................ 25
Lesson3-3 (External monitoring as well as firm securing and decentralized management/control of external facilities)(Serial no. 8) .............................................................................................................................................. 26
Lesson3-4 (Training to be able to respond to unforeseen situations) (Serial no. 9) ............................................... 27
Lesson3-5 (Operations with crisis management in mind) (Serial no. 10) ........................................................... 29
Lesson 4-1 (Members’ awareness) (Serial no. 11) ................................................................................................ 30
Lesson4-2 (Division of roles between on-site headquarters and support organizations) (Serial no. 12) ............... 31
Lesson4-3 (The job of the top individual in the hierarchy) (Serial no. 13)................................................................. 32
Lesson4-4 (Communication during an emergency) (Serial no. 14) ..................................................................... 33
Lesson 5-1 (Attitude toward accommodating new knowledge and environmental changes) (Serial no. 15) ...... 34
Lesson 6-1 (Culture where discussions can be held facing risks head on) (Serial no. 16) ................................... 35
Lesson7-1 (Adaptability to be able to respond to the unexpected) (Serial no. 17) ........................................... 35
Lesson7-2 (Reinforcement of resilience) (Serial no. 18) .......................................................................................... 37
Lesson7-3 (Develop the temperament and ability to face emergencies) (Serial no. 19)....................................... 39
Lesson8-1 (Improvement of the working environment) (Serial no. 20) ............................................................... 41
Lesson8-2 (Public announcements) (Serial no. 21)............................................................................................... 42
Lesson 8-3 (Public relations) (Serial no. 22)............................................................................................................. 43
Lesson 8-4 (International relations) (Serial no. 23)................................................................................................ 44<Attachments omitted for the following>

5. Precepts
1-1-1

Periodically verify plant design requirements in relation to natural phenomena as well as
preconditions about natural phenomena. (Precept 1) ........................................................................... 17
1-1-2 Confirm the pre-plant construction topography and foundation as well as history of any disasters.
(Precept 2) .................................................................................................................................................. 17
1-1-3 Events with a low probability of occurrence as well as uncertain events do occur. (Precept 3) .... 17
1-2-1 Endeavor to acquire cutting-edge information about research relating to safety. (Precept 4) ........ 18

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1-2-2 Verify the appropriateness of recurrence prevention measures from multiple aspects. (Precept 5)...................................................................................................................................................................... 18
1-2-3 Extensively utilize your own company’s experiences, other companies’ experiences, andinternational safety trends in improvement activities. (Precept 6) ...................................................... 18
1-2-4 Discern essential threats from cases experienced by other companies and analyze these
realistically as if they may also happen at your own plant. (Precept 7) ............................................. 18
1-3-1 Employ workable assessment methods and conduct no-holds-barred comprehensive risk
assessments. (Precept 8) ......................................................................................................................... 19
2-1-1 Confirm the limits of safety in relation to uncertain events and those with a low probability ofoccurrence, and implement countermeasures. (Precept 9)................................................................. 20
2-1-2 Give priority to the extent of the damage and prepare effective impact mitigation measures. (Precept10) ................................................................................................................................................................ 20
2-1-3 Honestly accept assessment results and link these to preventing and reducing any damage thatmight occur. (Precept 11) .......................................................................................................................... 20
2-1-4 Coordinate safety and security measures to prepare for a terrorist attack. (Precept 12) ................ 20
2-2-1 Systematically prepare systems, response procedures, facilities and other elements based on theconcept of defense in depth. (Precept 13) .............................................................................................. 22
2-2-2 Develop practical procedures systematically for responding as necessary during an emergency.
(Precept 14)................................................................................................................................................. 22
2-2-3 Construct a systematic education and training framework so that personnel may acquire knowledge
and skills for emergency response. (Precept 15) .................................................................................. 22
3-1-1 Consider waterproofing measures and inundation countermeasures when installing power sourcesand other important facilities. (Precept 16) ............................................................................................ 23
3-1-2 Enhance reliability by improving seismic performance, multiplexing, diversifying, ensuring
independence, and other measures. (Precept 17) ................................................................................ 23
3-1-3 Diversify telecommunication systems and also consider measures for recovery of such systems.
(Precept 18) ................................................................................................................................................ 23
3-1-4 From multiple perspectives, assess whether any risks are present in safety systems. (Precept 19)...................................................................................................................................................................... 23
3-2-1 Provide a full complement of spare parts and prepare various adapters for effectively utilizing
support facilities. (Precept 20) ................................................................................................................. 25
3-2-2 Establish a structure so that human beings are able to operate important valves and monitor key
parameters during an emergency. (Precept 21).................................................................................... 25
3-3-1 Strengthen the emergency response headquarters’ external monitoring functions and functions forverifying media coverage. (Precept 22) .................................................................................................. 26
3-3-2 Securely fasten outdoor facilities and decentralize management of heavy machinery and other items
outdoors. (Precept 23)............................................................................................................................... 26
3-4-1 For training, make use of severe scenarios, such as complex disasters, multiple simultaneous
disasters, etc. (Precept 24) ...................................................................................................................... 27
3-4-2 For training, develop rigorous configurations, such as a station blackout, loss of computer function,etc. (Precept 25) ......................................................................................................................................... 27
3-4-3 In training, assume a variety of obstacles arise during an emergency. (Precept 26)....................... 27
3-4-4 If part of an organization does not function in the emergency response framework, replace themissing entity. (Precept 27) ...................................................................................................................... 27
3-4-5 Agree on a support structure with relevant organizations that includes the specific details of support
to be provided during an emergency, support procedures, transport processes, and other elements.
(Precept 28) ................................................................................................................................................ 27
3-4-6 Construct a system for receipt of relief supplies that sorts necessary materials and delivers them tolocal sites. (Precept 29) ............................................................................................................................ 28
3-5-1 Conduct training where alternative measures are first secured and then the switchover operation
executed. (Precept 30).............................................................................................................................. 29
3-5-2 Even in normal times, understand the significance of procedures and operations, appropriately
apply these, and take action during an emergency. (Precept 31) ....................................................... 29
4-1-1 Conduct training in which trainees cope with scenarios while sharing objectives and confirming
basic policies. (Precept 32) ....................................................................................................................... 30
4-1-2 Training and competency evaluation systems are needed for understanding facilities and systems.
(Precept 33) ................................................................................................................................................ 30
4-1-3 Understand your own obligations, be aware of the weight of the responsibility, and takeresponsibility for your duties. (Precept 34) ............................................................................................. 30
4-1-4 Each functional team surveys the situation to gain an overall understanding and executes thenecessary support operations in coordination with other teams. (Precept 35) ................................. 30
4-2-1 Clarify that judgments about matters concerning the on-site response are to be entrusted to on-site
personnel. (Precept 36) ............................................................................................................................ 31
4-2-2 In good faith, on-site personnel shall judge the situation and execute actions to be taken. (Precept

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4-2-3 Clearly define the roles of support organizations. (Precept 38) .......................................................... 31
4-3-1 The top leader and executives give priority to measures that enable the organization to function
during an emergency situation. (Precept 39) ......................................................................................... 32
4-3-2 The base/stronghold for the emergency response is to be effective in terms of both personnel andenvironment. (Precept 40) ........................................................................................................................ 32
4-3-3 Authority is to be delegated to divide up the chain of command and allow the top leader to think.
(Precept 41)................................................................................................................................................. 32
4-4-1 Teams on-site check with the emergency response headquarters about operations that are very
important in terms of safety. (Precept 42) .............................................................................................. 33
4-4-2 The on-site team (main control room) and on-site headquarters properly share their recognition andunderstanding. (Precept 43)..................................................................................................................... 33
4-4-3 Be sure to utilize communication tools during an emergency. (Precept 44) ..................................... 33
5-1-1 In cases where the impact of the latest knowledge or a change in environment is considerable,
promptly link that to continuous improvements. (Precept 45) .............................................................. 34
5-1-2 The top leader conveys a strong commitment and utilizes reviews and other critiques provided byoutside organizations in order to continually enhance safety. (Precept 46)....................................... 34
5-1-3
Each individual maintains a stance of questioning and learning, and creates an organization inwhich there is good communication. (Precept 47) ................................................................................ 34
6-1-1 Do not get caught up in a safety paradox, but strive to enhance safety. (Precept 48)..................... 35
6-1-2 Disaster prevention plans that take the community residents’ perspective into account as well asasking the community for its understanding about the control of hazardous materials and other suchaspects leads to a sense of satisfaction and security among community residents. (Precept 49) . 35
6-1-3 In discussions about safety, eliminate the logic of numbers and the authority gradient within theorganization. (Precept 50) ........................................................................................................................ 35
7-1-1 Enhance inventiveness that goes beyond following procedures step-by-step. (Precept 51)........... 36
7-1-2 Think quickly and nimbly, and make use of all available people and things. (Precept 52).............. 36
7-1-3 Stipulate in advance workarounds (management) for unexpected work. (Precept 53) .................... 36
7-2-1 Train in a manner that contributes to making proper decisions in extreme situations. (Precept 54)...................................................................................................................................................................... 37
7-2-2 Link safety improvement activities carried out by each and every individual to continuous
improvements. (Precept 55) ..................................................................................................................... 37
7-2-3 Even in confusing situations, be sure to attend to important facilities within the context of the entire
system. (Precept 56) .................................................................................................................................. 37
7-2-4 Bring out people’s adaptability and enhance resilience through training. (Precept 57) ................... 37
7-3-1 During an emergency, give priority to time factors and adopt a feasible means within the limited
time. (Precept 58) ...................................................................................................................................... 39
7-3-2 Prepare procedures for work that requires special skills and secure operation personnel. (Precept59) ................................................................................................................................................................ 39
7-3-3 To improve the ability to manage crises, repeatedly conduct training and verification premised on
the assumption that a severe situation will actually arise. (Precept 60)............................................. 39
7-3-4 Appropriately grasp changes in the environment and give priority to making sure that relevant
personnel (within the company, country, and overseas) share information. (Precept 61) ............... 39
7-3-5 Anticipate changing conditions and prepare a system for sharing information that does not place agreater burden on teams in the field. (Precept 62) ................................................................................ 40
8-1-1 Protect employees from the disaster and do everything possible to bring the accident to a resolution
with a long-term safety and health management framework. (Precept 63) ....................................... 41
8-1-2 Establish a system in preparation for a prolonged response that includes water, food, hygiene
maintenance, health management, and other such elements. (Precept 64)..................................... 41
8-1-3 When an emergency arises, ascertain the safety of the families of responders. (Precept 65) ....... 41
8-2-1 Focus on risk communication on a daily basis and aim, when making public announcements, for
information “to be conveyed.” (Precept 66) ............................................................................................ 42
8-2-2 Reach an agreement within the organization and among relevant organizations on improving theefficiency of preliminary understandings during an emergency. (Precept 67) .................................. 42
8-3-1 Minimize accommodation of visitors that are obligated to come to inspect or enter the station during
an emergency. (Precept 68)..................................................................................................................... 43
8-3-2 In cases of humanitarian public relations, place top priority on ensuring the safety of the visitors.
(Precept 69) ................................................................................................................................................ 43
8-4-1 In cases where there are differences between international rules and national rules, ascertain
clearly what those differences are. (Precept 70) ................................................................................ 44
8-4-2 Ascertain the necessary procedures regarding measures for dealing with hazardous materials andother events that might emerge as an international issue. (Precept 71) ........................................... 44

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< Attachments >Attachment 1.1

Reflections on the “Outline of the Central Disaster Prevention Council” and “Expert
Examination Committee on Earthquake and Tsunami Using Lessons Learned from theGreat East Japan Earthquake”.................................................................................... 327
Attachment 2.1 Jogan earthquake and long-term assessments.............................................................. 332
Attachment 2.2
Record of the Jogan earthquake and tsunami: Veritable Records of Three Reigns ofJapan.......................................................................................................................... 336
Attachment 3.1 History behind revision of seismic durability guidelines and overview of the new seismic
durability guidelines.................................................................................................... 338
Attachment 3.2 Explanation of terms relating to seismic design review guidelines ........................................ 341
Attachment 3.3 Steps in seismic safety assessments............................................................................ 344
Attachment 3.4 Root causes underlying SA measures, tsunami countermeasures, and accident
response..................................................................................................................... 347
Attachment 3.5 Impact of earthquakes on important equipment and piping systems............................. 351
Attachment 4.1 Hydro-zirconium reaction….......................................................................................... 356
Attachment 5.1 Blowout panels…........................................................................................................... 360
Attachment 5.2 Did the rupture disc function? ….................................................................................. 362
Attachment 5.3 Role of rupture discs…................................................................................................ 366
Attachment 5.4 There was bypass flow in the Unit 1 fire engine coolant injection. ...............................369
Attachment 6.1 Overview of JANSI’s data analysis and evaluation activities........................................ 375
Attachment 6.2 Reflections on the use of operating experience and initiatives to address external
reviews....................................................................................................................... 378
Attachment 6.3 There are limits to disaster prevention measures that are only accumulations of recurrence
prevention................................................................................................................... 385
Attachment 7.1 Description of B.5.b…................................................................................................... 388
Attachment 7.2 Description of investigation conducted by the NRC to verify the status of responses to
B.5.b........................................................................................................................... 392
Attachment 7.3 Awareness of issues pertaining to the inability to obtain B.5.b information and inability to
implement antiterrorism measures autonomously....................................................... 395
Attachment 7.4 Cases where information about operating experiences in other countries was unable to be
utilized: Blayais, M’anshan, and Madras...................................................................... 401
Attachment 7.5 Weaknesses in the system for screening information about operating experiences...... 405
Attachment 8.1 Reflections of people involved with nuclear power and how to approach nuclear power inthe future.................................................................................................................... 407
Attachment 8.2 Awareness of issues relating to risk management ....................................................... 417
Attachment 8.3 Consideration did not extend to a loss of power station function caused by a massive
tsunami (risk management before the accident in relation to earthquakes and tsunamis)………………………………………………………………………………………………... 425
Attachment 8.4 Summary of efforts to address shortcomings in safety design..................................... 428
Attachment 9.1 Promptly implementing feasible countermeasures when hazard analysis reveals highpotential for cliff edge effect........................................................................................ 434
Attachment 9.2 Overview of the Japan Society of Civil Engineers’ tsunami assessment technology.... 437
Attachment 9.3 Was the height of the tsunami caused by the Great East Japan Earthquake unable to be
estimated?……………………………………………………………………….………….. 440
Attachment 9.4 Awareness of issues relating to tsunami response....................................................... 448
Attachment 9.5 TEPCO’s basic stance toward the accident .................................................................. 454
Attachment 9.6 Conditions when the tsunami struck (tsunami height indicator observation results) ..... 457
Attachment 10.1 FLEX strategies in the United States........................................................................... 460
Attachment 10.2 Cost of FLEX strategies in the United States and cost of accommodating new regulatory
requirements in Japan ................................................................................................ 464
Attachment 10.3 Awareness of issues relating to not having adopted tsunami countermeasures........... 466
Attachment 10.4 Reasons why the backfits were not implemented......................................................... 470
Attachment 10.5 AM measure steps in Japan......................................................................................... 472
Attachment 11.1 Was a massive tsunami unexpected? .......................................................................... 479
Attachment 11.2 Reinforcement of seals on the sea water pump motor can hardly be considered aneffective and sufficient tsunami countermeasure......................................................... 483
Attachment 12.1 In order to respond to terrorism................................................................................... 486
Attachment 12.2 Anti-terrorism measures that also work as severe accident countermeasures............. 494
Attachment 12.3 Nuclear power plants and cybersecurity ...................................................................... 498
Attachment 13.1 Need for risk management that enhances resilience …................................................ 501

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Attachment 13.2 Awareness of issues about objections to regulation of accident management….......... 506
Attachment 13.3 Root cause analysis results of the accident.................................................................. 509
Attachment 13.4 Comprehensive view of facility (tangible) countermeasures and shortcomings in design
diagram documents .................................................................................................... 513
Attachment 14.1 System diagram of containment vessel vents.............................................................. 521
Attachment 14.2 System diagram of alternate coolant injection line….................................................... 523
Attachment 15.1 Systematic approach to training (SAT) ....................................................................... 526
Attachment 16.1 Inundation damage differing depending upon the level on which power supply facilities
are installed and differences in inundation pathways................................................. 529
Attachment 17.1 Power supply systems that avoided inundation damage as a system......................... 534
Attachment 17.2 Emphasis on diversity................................................................................................. 538
Attachment 18.1 Communication systems that ensure diversity............................................................ 541
Attachment 19.1 Necessity for enhancing safety by means of design modifications ............................. 546
Attachment 19.2 System diagram of isolation condenser (IC) and illustration of IC isolation valve
operation…………………………………………………………………...………………... 549
Attachment 19.3 Operation and design of Oyster Creek isolation condenser (fail-safe function) .......... 553
Attachment 20.1 Success of emergency procurement and transport of relief equipment and materials for
Fukushima Daini ....................................................................................................... 556
Attachment 20.2 FLEX strategies in the United States.......................................................................... 562
Attachment 21.1 Process for improving operators and maintenance personnel’s technical capabilities... 565
Attachment 21.2 On-site hardships: operation of suppression chamber (S/C) vent valves ..................... 568
Attachment 22.1 Acquisition of external information at the power station response headquarters (baseisolated building) ....................................................................................................... 571
Attachment 22.2 Installation of monitoring cameras to ascertain situation on-site.................................. 574
Attachment 23.1 Heavy oil tanks swept away in the tsunami................................................................... 577
Attachment 23.2 Storage locations for portable severe accident management equipment....................... 580
Attachment 24.1 Necessity for training plans anticipating complex disasters and simultaneous disasters at
multiple units.............................................................................................................. 586
Attachment 24.2 Passive stance toward nuclear emergency response training anticipating complex
disasters .................................................................................................................... 590
Attachment 24.3 Number of personnel required for response organizations .......................................... 593
Attachment 24.4 Matters that may have turned into risk factors in the accident response...................... 598
Attachment 25.1 Overview of the Safety Parameter Display System (SPDS) ......................................... 604
Attachment 25.2 Methods of coping when information sharing systems are unavailable: utilization of data
templates................................................................................................................... 608
Attachment 25.3 Overview of Emergency Response Support System (ERSS) and System for Protection ofEnvironmental Emergency Dose Information (SPEEDI) ............................................. 611
Attachment 26.1 Numerous passage hindrances due to earthquake and tsunami.................................. 616
Attachment 26.2 Number of aftershocks and their effect in Futaba town................................................. 620
Attachment 27.1 Overview of nuclear emergency response-related organizations and composition oforganizations at off-site centers ................................................................................. 625
Attachment 28.1 Achievements in procuring power generation vehicles and fire engines...................... 636
Attachment 28.2 Roles of emergency response organizations assuming a temporal transition.............. 645
Attachment 29.1 Mechanisms for selecting support that does not hinder accident resolution or response
and is truly necessary................................................................................................. 651
Attachment 29.2 Status of support from other countries......................................................................... 657
Attachment 30.1 Goals in the initial reponse........................................................................................... 661
Attachment 30.2 System diagram of the reactor core isolation cooling (RCIC) system and illustration of theoperating principles of the main steam release safety (SR) valve................................ 664
Attachment 30.3 Organizational factors in the on-site response confusion............................................. 672
Attachment 30.4 Misunderstanding of operating status of the emergency isolation condenser (IC) ......... 675
Attachment 30.5 Factors leading to success at Fukushima Daini: recovery strategy prioritization andleadership.................................................................................................................. 679
Attachment 30.6 Views on differences between Fukushima Daiichi and Fukushima Daini in the abilities ofstation personnel....................................................................................................... 683
Attachment 31.1 Switchover of water sources supplying the RCIC at Fukushima Daini......................... 685
Attachment 32.1 Awareness of the issue that power station headquarters was swamped with inquiries fromthe Head Office headquarters.................................................................................... 689
Attachment 34.1 Police officers and fire brigade members who acted with a sense of duty during theearthquake................................................................................................................. 693
Attachment 34.2 Problem of not wearing active personal dosimeters (APD) equipped with alarms....... 698
Attachment 35.1 Background of the decision to continue injecting seawater........................................... 703
Attachment 35.2 Emergency response headquarters as a vertical compartmentalized organization....... 708
Attachment 36.1 Roles of the head office response headquarters......................................................... 715

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Attachment 36.2 Roles of the shifts, power station response headquarters, and head office response
headquarters………………………………………………………………………………. 718
Attachment 36.3 Approach for emergency response organizations at the head office in line with the Incident
Command System (ICS) approach........................................................................... 722
Attachment 36.4 Clarification of division of responsibilities granting decision-making authority to fieldcommanders (Incident Command System (ICS)) ...................................................... 726
Attachment 37.1 Impact of Prime Minister’s statement about withdrawing on TEPCO personnel.............. 728
Attachment 38.1 Diagram outlining the entire organization, including of those the central government,
prefecture, and operator, during the Fukushima Daiichi accident............................... 732
Attachment 38.2 What is the Incident Command System (ICS)? ........................................................... 736
Attachment 39.1 Setting supervisory limits based on the Incident Command System (ICS) .................... 745
Attachment 39.2 Reflections of Superintendent Yoshida on misunderstanding the operating status of theemergency isolation condenser (IC) .......................................................................... 749
Attachment 39.3 Emergency organizations adopting the Incident Command System (ICS) .................. 760
Attachment 40.1 Diagram of entire coolant injection system, including alternate coolant injection ........... 764
Attachment 40.2 Switchover from high-pressure coolant injection system to low-pressure coolant injection
system at Unit 3.......................................................................................................... 769
Attachment 40.3 Problems relating to loss of coolant injection function at Unit 3 (HPCI manual shutdown
and SRV failure to depressurize) ............................................................................... 774
Attachment 41.1 Views on procedures for manual shutdown of high-pressure coolant injection (HPCI)
system at Unit 3......................................................................................................... 780
Attachment 42.1 Misunderstanding of operating status of the emergency isolation condenser (IC) ........ 784
Attachment 42.2 Background behind misunderstanding operating status of the emergency isolation
condenser (IC) ........................................................................................................... 788
Attachment 42.3 Views on questioning shift crew judgments about manually shutting down the Unit 3 highpressure coolant injection (HPCI) system .................................................................. 796
Attachment 42.4 Authorities and roles of main control room and power station response
headquarters.............................................................................................................. 802
Attachment 43.1 Views on containment vessel vents and coolant injection delay: impact of
misunderstanding IC operating status......................................................................... 809
Attachment 43.2 System diagram of alternate coolant injection system and operating conditions of
DDFP......................................................................................................................... 813
Attachment 43.3 System configuration of isolation condenser (IC) and power configuration of IC isolation
valve........................................................................................................................... 818
Attachment 44.1 Human performance improvement tools...................................................................... 823
Attachment 45.1 Assumptions about massive earthquakes occurring in long-term assessments............ 829
Attachment 45.2 Awareness of issues concerning passive efforts for new knowledge............................ 831
Attachment 46.1 Seven Principles of JANSI’s Safety Culture.................................................................. 838
Attachment 46.2 Comparison between the degree of deterioration in IAEA safety culture and TEPCO’s
behavior..................................................................................................................... 844
Attachment 46.3 Expectations for JANSI activities................................................................................. 848
Attachment 47.1 Importance of a questioning and learning attitude........................................................ 854
Attachment 48.1 Why was the accident scenario unable to be anticipated? ......................................... 858
Attachment 48.2 Views on not having publicly announced the risk of a tsunami strike exceeding
expectations............................................................................................................... 864
Attachment 48.3 Structuring of nuclear public relations that leads to formation of the myth of safety..... 867
Attachment 48.4 Problems pertaining to delays that occurred in severe accident countermeasures....... 869
Attachment 48.5 Factors underlying the failure to adopt tsunami countermeasures............................... 873
Attachment 49.1 3 Views about directly releasing radioactive materials from the Unit 3 primary containment
vessel......................................................................................................................... 878
Attachment 49.2 Development of risk communication........................................................................... 880
Attachment 50.1 Case of adverse impact of the authority gradient (airline industry) ............................. 883
Attachment 51.1 Line for simultaneous cooling of suppression chamber (S/C) and reactor................... 888
Attachment 52.1 On-site photos (main control room temporary lighting and temporary batteries) ......... 892
Attachment 52.2 Illustration of the operating principle of an air-operated value (AO valve) ...................... 897
Attachment 53.1 Significance of composition of the fire protection (FP) system alternate coolant injection
line set up early by shift personnel .............................................................................. 901
Attachment 53.2 About coolant injected using fire engines that were shut down after fuel was
exhausted.................................................................................................................. 906
Attachment 54.1 Statements by on-site teams: severe conditions on-site during the accident............... 909
Attachment 54.2 Leadership of Superintendent Yoshida during the hydrogen explosions..................... 916
Attachment 55.1 Approaches to the application of countermeasures for important facilities.................. 921
Attachment 55.2 Proposal system for maintaining awareness about enhancing safety......................... 928
Attachment 55.3 Problems with QMS.................................................................................................... 931

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Attachment 55.4 Improvements in QMS................................................................................................ 936
Attachment 56.1 System diagram of high-pressure coolant injection (HPCI) system............................ 940
Attachment 56.2 Proper understanding of conditions for core cooling in the United States................... 944
Attachment 56.3 Distinguishing features of the Incident Command System (ICS) (as pertains to information
sharing)…………………………………………………………………………………..... 946
Attachment 57.1 Necessity for training in anticipation of a severe accident so as to strengthen
resilience................................................................................................................... 950
Attachment 57.2 Measures making use of directly-managed work to enhance technical capabilities..... 954
Attachment 58.1 FP system coolant injection by means of fire engines should be prioritized over that using
the SLC………………………………….…………………………………………………... 956
Attachment 58.2 SLC power restoration work, RCIC operating conditions, and HPCI operating
conditions................................................................................................................... 961
Attachment 58.3 Phased approach to modifying the response as time allows....................................... 968
Attachment 59.1 Operation of heavy equipment, etc. (reflections of Superintendent Yoshida), andmovement of people starting on the 12th..................................................................... 971
Attachment 59.2
Description of directly-managed work for operators and maintenancepersonnel................................................................................................................... 976
Attachment 59.3 Partner company support and division of roles............................................................. 981
Attachment 60.1 Illustration of isolation condenser (IC) isolation valve.................................................... 984
Attachment 60.2 Isolation valve requirements, drive power supply, control power supply, and control
circuits……………………………………………………..…………………………………. 988
Attachment 60.3 Mechanism of reactor water level gauges and reactor pressure gauges, and factors
resulting in erroneous reactor water level gauge measurement or display................. 993
Attachment 60.4 Plan for practical training............................................................................................ 999
Attachment 60.5 Critique of the central government’s general emergency drills, TEPCO’s efforts to address
severe accidents, and efforts to address emergency response training.....................1002
Attachment 61.1 Number of resident foreign nationals and foreign visitors to Japan............................1005
Attachment 62.1 Achievements of reinforcements from both inside and outside the company in responding
to the Fukushima Daiichi during the initial stage of the disaster.................................1008
Attachment 62.2 Scale and other attributes of personnel necessary for the initial response based on thenumber of operating units........................................................................................1014
Attachment 63.1 Condition of the main administrative building after the earthquake...........................1017
Attachment 63.2 Handrails in the main control room...........................................................................1020
Attachment 64.1 Need for long-term response readiness, the state of employees’ health, and conditions
for permanently stationing a physician.....................................................................1022
Attachment 64.2 Efforts to reduce exposure dose and exceedance of dose limits in the base-isolatedbuilding and main control room................................................................................1026
Attachment 64.3 Logistic support activities as one factor in the success at Fukushima Daini..............1034
Attachment 64.4 Amount of food stockpiled and other conditions at power plants hit by disaster.............1037
Attachment 65.1 Statements by on-site teams: statements concerning families...................................1040
Attachment 65.2 Importance of ascertaining the safety of families: Ministry of Defense business continuity
plan..........................................................................................................................1044
Attachment 66.1 Views on comments made about concealing information, not acknowledging core
meltdown, and trivializing the situation......................................................................1047
Attachment 66.2 Reflections on public relations activities during the accident......................................1052
Attachment 66.3 Factual record concerning the withdrawal issue.........................................................1056
Attachment 66.4 Stance toward public disclosure: emphasizing operator’s reputation in relation to thegovernment rather than information transparency.....................................................1062
Attachment 67.1 Views on factors requiring time in disclosing information and inadequate explanations bymanagement ............................................................................................................1067
Attachment 67.2 Awareness of systemic issues and problems in public disclosure of information during an
emergency………………………………………………...……………………………......1072
Attachment 68.1 Prime Minister’s visit to Fukushima Daiichi during the accident: local reaction…........1075
Attachment 69.1 Acceptance of local Onagawa town evacuees at Onagawa Nuclear Power Station...1082
Attachment 70.1 Examination of evacuation order standards...............................................................1085
Attachment 70.2 Ministry of the Environment’s view on evacuation order standards............................1088
Attachment 70.3 Protective measures during a nuclear emergency.....................................................1093
Attachment 71.1 Ocean release of radioactive materials......................................................................1105< Appendices >Appendix 1 Overview of accident at Fukushima Daiichi Nuclear Power Station .................................1110
Appendix 2 Overview of Fukushima Daiichi Nuclear Power Station (from JANTI report) .....................1126

C-8

Appendix 3 Overview of the Great East Japan Earthquake and accompanying tsunami......................1131
Appendix 4 Mechanism of nuclear power generation.........................................................................1136
Appendix 5 Measures based on the new regulatory requirements (examples) ...................................1141
Appendix 6 Glossary (from JANTI report) ..........................................................................................1148
Appendix 7 Abbreviations (from JANTI report) …...............................................................................1168

Please consult JANSI before reproducing any part of this publication.

C-9

Reclassification of Lessons and Other Wisdom Gained fromthe Fukushima Daiichi Nuclear Power Station Accident andConstruction of a Search System－Focusing on Facility Operation－

1. Introduction
It has been 10 years since the Fukushima Daiichi Nuclear Power Station accident (“theaccident”) and nuclear power stations have been striving to make many improvements not
only to their facilities, but also in their operations.
JANSI was established in 2012 with the purpose of encouraging operators’ efforts tovoluntarily and continually engage in safety enhancement activities. JANSI has worked toreflect lessons that we have learned so far from the accident in voluntary safety efforts.
In marking the 10th year since the accident, JANSI decided to prepare this publication,
which is based on lessons extracted so far, to help users easily verify and utilize relevantcases and matters indicated among the tremendous volume of reports compiled about theaccident. This will allow operators to routinely learn and actually apply the lessons of theaccident. JANSI has reclassified the lessons from the various reports and other publications,which were released after the accident, and constructed a search system that traces backto the actual events and facts upon which the lessons are based.
In this reclassification of lessons learned, JANSI has drawn upon the seven areas
presented in the Chairperson’s Remarks of the Final Report of the Investigation Committee
on the Accident at the Fukushima Nuclear Power Stations of Tokyo Electric Power
Company (“Japanese Government’s Investigation Committee Report”) that serve here as
seven facets of knowledge for re-examining what has been learned from a broader
perspective. These seven facets of knowledge apply not only to nuclear power, but may
also be regarded as an arrangement of universal elemental knowledge. It is hoped that use
and application of the seven facets will have the following effects.
① To serve as a foundation when reclassifying lessons relating to facility operation.
② To provide a uniform organization no matter what lessons or matters have been
pointed out in any report.
③ To enable a systematic arrangement in a manner current not only for the nuclear
industry, but other industries as well.
JANSI has reclassified and organized all available material and data into seven facets ofknowledge (classified for convenience into eight categories), 23 lessons learned, 71
precepts, as well as 175 related attachments and 7 appendices compiled into a databaseon the accident.
In addition, two search guides were prepared: one that enables users not only to find theknowledge, lessons, and precepts, but also go back to pinpoint the events and facts uponwhich these are based, and another allowing users to identify the actual relevant
documentation. The former is searchable using the No. or keyword of the relevant Q,
knowledge, etc.. The latter is searchable by document title to find the actual document (both1full text and excerpts).
As progress is made in clarifying facts, additional lessons will likely be learned. It is also
conceivable that, as we take a fresh perspective in examining documents referenced here
as well as other documentation, we may discover additional lessons to be learned. The
search system will need to be continually improved as well.

22. Overview
Based on the 7+1 facets of knowledge, 71 precepts were extracted. These 71 precepts
have been classified and organized into 23 lessons.
Looking at these 23 lessons and 71 precepts, one again realizes that each and every oneof these is reasonable, natural, proper, and familiar. In the process of arranging these lessons
and precepts, a solid realization emerged that “if ordinary tasks or work are not performed ona daily basis, then ordinary tasks or work can never be executed in an emergency.” Thesolution is “to simply practice the ordinary on a daily basis and continually train to carry out
such work in preparation for an emergency.” Still, many barriers are present in organizations
to doing ordinary things. It should be clearly understood that it is difficult to establish such apractice unless the organization’s top leader, executives, mid-level management, andpractitioners share a common understanding that ordinary tasks should be properly done.
While it is a given that the Fukushima Daiichi Nuclear Power Station accident must neverbe repeated, the lessons learned from this accident are not necessarily specific to nuclear
power. Again, there is a sense that everyone engaged in any of the many industries working
with hazardous materials should find these values worthy of consideration.
When using this collection of lessons for training power station personnel, it should be kept
in mind that staff must not memorize these lessons in the belief they are correct as dictated.
Even though lessons appropriate to a variety of circumstances have been arranged in asearchable format and it is hoped that progress will be made in utilizing these lessons, it isimportant for individuals to think for themselves about what course of action should be taken sothat they can acquire and demonstrate resilience and adaptability during an emergency. JANSI
asks users to consider combining this collection of lessons with a variety of other training
materials so that the lessons may be utilized in a balanced and unbiased manner.

3

3. Knowledge
Knowledge 1. Things that are possible happen. Things that are thought notpossible also happen.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks pp.
444-445(1) Things that are possible happen. Things that are thought not possible also happen.
【Excerpt】
The direct cause of this accident can be traced back to the fact that everything was built andoperated based on the premise that “an extended station blackout will not happen.” Themindset should be that “things that are possible happen.” Furthermore, there is a need to beaware at the same time that phenomena that are not even adequately recognized – in thesense that “we consider it impossible” – can happen as well. To put it another way:
“Phenomena that have never even been thought about can also happen.”【Full text】
The direct cause of this accident can be traced back to the fact that everything was built andoperated based on the premise that “an extended station blackout will not happen.” However,by rights the mindset should be “things that are possible happen.” In February 2012, after thisInvestigation Committee had compiled its Interim Report, an international meeting withparticipation of the foreign experts was held. At that meeting, experts from France and othercountries pointed out that in the nuclear power sector “you have to think that the improbablemay also happen (improbable est possible).” In considering what sorts of things should bethought about, the most important point is to think based on experience and logic. This involves
learning about incidents and experiences that have taken place in the past both at home andabroad and considering all the elements involved, to discover the things that could logicallyoccur. The fact that something has a low probability of occurrence does not mean it will notoccur. It is a mistake to believe that events with a low probability of occurrence or events thatare not established as knowledge do not need to be considered and that responses to them do
not have to be made.
Furthermore, there is a need to be aware at the same time that phenomena that are noteven adequately recognized – in the sense that “we consider it impossible” – can happen as
well. To put it another way: “Phenomena that have never even been thought about can also
happen.”Key sentences The direct cause of this accident can be traced back to the fact that everything was built andoperated based on the premise that “an extended station blackout will not happen.”4 This involves learning about incidents and experiences that have taken place in the past
both at home and abroad.
 and considering all the elements involved, to discover the things that could logicallyoccur.
 It is a mistake to believe that events with a low probability of occurrence or events that are
not established as knowledge do not need to be considered and that responses to them do nothave to be made.

5

Knowledge 2. You cannot see things you do not wish to see. You can see
what you wish to see.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks p.
445(2) You cannot see things you do not wish to see. You can see what you wish to see.
【Excerpt】
When people see and think about things, they tend to view only what they themselves
consider agreeable and only the course they are trying to take; they cannot see things they
do not want to see or things that are inconvenient. There is a need to be constantly selfaware that one’s views are biased not only by one’s own interests but by the various
influences of the organization, society and the times that surround one, and to be consciousthat something is always overlooked.
【Full text】
When people see and think about things, they tend to view only what they themselves
consider agreeable and only the course they are trying to take; they cannot see things
they do not want to see or things that are inconvenient*. The impact of this kind of human
psychology can be glimpsed in TEPCO’s natural disaster preparedness, which were notoutfitted with AM measures for tsunami, and did not provide for a situation involving asimultaneous and complete loss of power at several reactor facilities. To prevent
situations like this, there is a need to be constantly self-aware that one’s views are biased
not only by one’s own interests but by the various influences of the organization, society
and the times that surround one, and to be conscious that something is always overlooked.
This is even applicable to this Investigation Committee’s reports. This Committee has
not shed light on the complete picture of the Fukushima NPS accident – it is simply one
milestone on the road to clarifying the facts of the accident. I do urge that the people
striving to clarify the causes of the Fukushima NPS accident carry out follow-up checks
from here on to see if there were omissions or errors, and based on those findings makeongoing efforts toward further clarifying the facts and preventing accidents.
* In Volume III, Chapter 18 of the “The Gallic Wars,” Julius Caesar’s account of
the successful ploy waged by his legate Sabinus against the Veneti, Caesar wrotethat “fere libenter homines id quod volunt credunt” (“Men readily believe what theywant to believe”). This phrase has been liberally translated as “people only see
what they themselves want to see” or “people only see what they desire and want
to see” and has come to be known as one of Caesar’s maxims.
[Supplement] AM: Accident managementKey sentences6 [t]hey tend to view only what they themselves consider agreeable and only the course
they are trying to take; they cannot see things they do not want to see or things that areinconvenient*.
 …there is a need to be constantly self-aware that one’s views are biased…and to
be conscious that something is always overlooked.

Knowledge 3. Assume to the extent possible and make full preparations.
Commentary Japanese Government’s Investigation Committee Report (Final) Chairperson’s
Remarks pp. 445-446(3) Assume to the extent possible and make full preparations.
【Excerpt】
It is vital to take preventative measures for accidents and disasters by constantly
reviewing what is possibly assumable, without adhering tenaciously to assumptions madeat a previous point in time. It is likewise essential to make adequate preparations basedon the mindset that circumstances that have not even been thought of up to now canoccur.
【Full text】
It is important to assume to the extent possible and to prepare fully. It is also necessary
to acknowledge the possibility that things may happen that have not even been thoughtof and make provisions so that they do not reach the point of becoming worst-casescenarios. In the Fukushima NPS accident, the result of investigations show that
substantial provisions had been made against earthquakes and it was not possible toconfirm that key facilities had stopped functioning as a result of the earthquake itself, but
it is conceivable that because preparations were not in place for a scenario in which thesite was struck by a tsunami that exceeded assumptions, responses to the situation could
not be made, and this resulted in the major accident. If new knowledge – even if not fully
confirmed – had been taken on board, with tsunami assumptions revised and adequate
preparations made accordingly, or if adequate preparations had been made for the adventof unforeseen circumstances, there is a possibility the situation would not have escalated
into a major accident of this level.
It is easy to say things like this in hindsight, but extremely difficult to adopt this mindset
at a time when nothing is actually happening. Nonetheless, it is vital to take preventative
measures for accidents and disasters by constantly reviewing what is possibly assumable,
without adhering tenaciously to assumptions made at a previous point in time, such as at
the design stage. It is likewise essential to make adequate preparations based on themindset that circumstances that have not even been thought of up to now can occur.

7Key sentences It is important to assume to the extent possible and to prepare fully. It is also
necessary to acknowledge the possibility that things may happen that have not evenbeen thought of and make provisions so that they do not reach the point of becoming
worst-case scenarios.

8Knowledge 4. Creating a framework alone does not mean it will function.
Frameworks can be constructed but goals not collectively shared.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks(4) Creating a framework alone does not mean it will function. Frameworks can be constructedbut goals not collectively shared.
【Excerpt】
Operators, regulatory-related institutions and regional municipalities had each createdframeworks to respond to nuclear accidents in a formal sense, but when an accident
ultimately occurred those responses were found to be flawed in places. Conceivably, thatwas because the members of those organizations were not fully conscious of what thoseframeworks’ goals were, and what they had been entrusted with by society. It is necessary
to create an atmosphere in which each member of an organization is constantly thinking
about what they have been entrusted with by society, what position they occupy in theorganization overall, and how their job affects the organization overall.
【Full text】
Operators, regulatory-related institutions and regional municipalities had each createdframeworks to respond to nuclear accidents in a formal sense, but when an accident
ultimately occurred those responses were found to be flawed in places. Conceivably, thatwas because the members of those organizations were not fully conscious of what thoseframeworks’ goals were, and what they had been entrusted with by society. Without
creating an environment in which each member is conscious of what they have to do as apersonal issue, even if a framework is created it will not function as one whole. That is
because its goals are not collectively shared. The fact that SPEEDI’s system, constructed
for times of emergency, was not used for the evacuation strategy is most certainly an
example of this.
In order to ensure sharing goals by all members of an organization, it is necessary tocreate an atmosphere in which each member is constantly thinking about what they havebeen entrusted with by society, what position they occupy in the organization overall, andhow their job affects the organization overall. Furthermore, education and training areneeded in order to maintain that atmosphere. Social management must be undertaken to
ensure that each member is precisely aware of the matters that society has entrusted
them with.
Key sentences
Without creating an environment in which each member is conscious of what they haveto do as a personal issue, even if a framework is created it will not function as one whole. Thatis because its goals are not collectively shared.
In order to ensure sharing goals by all members of an organization, it is necessary tocreate an atmosphere in which each member is constantly thinking about what they have been
entrusted with by society, what position they occupy in the organization overall, and how theirjob affects the organization overall.

Furthermore, education and training are needed in order to maintain that atmosphere.
Social management must be undertaken to ensure that each member is precisely aware of the9matters that society has entrusted them with.

10

Knowledge 5. Everything changes, respond flexibly to changes.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks pp.
446-447(5) Everything changes, respond flexibly to changes.
【Excerpt】
When given conditions are considered to be fixed, then detailed and (superficially atleast) commendable responses are possible. However, given conditions are constantly
changing, and unless responses that meet those changes are constantly sought out,
they become inconsistent with the actual circumstances. The only way is to consider that
all matters will change, pay scrupulous attention to observation, show humility in being
open to external ideas, and continue to respond appropriately.
【Full text】
When given conditions are considered to be fixed, then detailed and (superficially atleast) commendable responses are possible. However, given conditions are constantly
changing, and unless responses that meet those changes are constantly sought out, they
become inconsistent with the actual circumstances. For example, as a result of progressthat had been made in investigative research on earthquakes and tsunami, a theory had
emerged that it was possible an earthquake and tsunami on a larger scale than had
previously been considered could occur off the coast of Fukushima Prefecture. Those
concerned were aware of this new theory, and had taken measures of sorts, but from thestandpoint of preventing the disaster, ultimately those measures came up short. From
here on, the only way to stop situations such as this from happening is to consider that all
matters will change, pay scrupulous attention to observation, show humility in being open
to external ideas, and continue to respond appropriately.
Key sentences
[G]iven conditions are constantly changing, and unless responses that meet thosechanges are constantly sought out, they become inconsistent with the actual
circumstances.

 [T]o consider that all matters will change, pay scrupulous attention to observation,
show humility in being open to external ideas, and continue to respond appropriately.

Knowledge 6. Acknowledge that risks exist, and create a culture in which it
is possible to debate the risks head on.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks p.
447

11

(6) Acknowledge that risks exist, and create a culture in which it is possible to debate the risks
head on.
【Excerpt】
Asserting that risks should be completely excluded despite the fact that no-one iscapable of foreseeing completely what type of situations may arise is dangerous in that it
may lead to creating “a safety myth” in which the existence of unlikely risks is ruled out.
Without creating a culture in which risks are acknowledged as risks, and in which it ispossible to debate those risks head on, major risks end up being shrouded in a veil ofsafety and left unresolved.
【Full text】
Refusing to permit the existence of risks and reasoning that they should be completely
excluded seems at a glance a sincere way of thinking, but on occasions this does notmatch reality. Asserting that risks should be completely excluded despite the fact that noone is capable of foreseeing completely what type of situations may arise is dangerous
in that it may lead to creating “a safety myth” in which the existence of unlikely risks is
ruled out. Nuclear power has an extremely high energy density, and is essentially
dangerous, yet it cannot be denied that in spite of that, attempts have been made topromote the use of nuclear power as an energy source with no risks in order to dispel
society’s unease. Nuclear emergency response manuals were not equipped to deal witha large-scale disaster such as this one, and emergency response drills prior to the event
were also insufficient, and in this and other ways the nuclear emergency preparedness
was inadequate. There is no denying that the misguided perception that a major accident
in which large quantities of radioactive material would be released could not happen at
Japan’s nuclear power stations formed a backdrop to that inadequacy.
Denying the existence of risks will not only lead to a rigid mindset that becomes outof sync with the actual situation, it also makes it impossible to take the disaster-prevention
and disaster-mitigation measures truly necessary. Trying to exclude risks completely
generates unnecessary costs, and it also becomes impossible to discuss and carry out
disaster-management measures in order to prevent damages from growing and alleviate
their impact once risks end up becoming actualized. Without creating a culture in whichrisks are acknowledged as risks, and in which it is possible to debate those risks headon, major risks end up being shrouded in a veil of safety and left unresolved, and this isa pattern not limited to nuclear power.
That being the case, when examining one matter it becomes necessary to look directly
and simultaneously at the benefits and risks it brings, and to make a judgment while
undertaking a balanced consideration of those factors. At that point, if opposing ideas arenegated and the matter in question is dealt with based on one side’s ideas alone without
genuine debate taking place, the worst path will be followed. This severe accident
demands that we Japanese change our mindset.

Key sentences Asserting that risks should be completely excluded…is dangerous in that it may lead tocreating “a safety myth” in which the existence of unlikely risks is ruled out.
 There is no denying that the misguided perception that a major accident in which large
quantities of radioactive material would be released could not happen at Japan’s nuclear
power stations formed a backdrop to that inadequacy.

12 Denying the existence of risks will not only lead to a rigid mindset that becomes out ofsync with the actual situation, it also makes it impossible to take the disaster-prevention anddisaster-mitigation measures truly necessary.
 Without creating a culture in which risks are acknowledged as risks, and in which it ispossible to debate those risks head on, major risks end up being shrouded in a veil of safety
and left unresolved, and this is a pattern not limited to nuclear power.
 [I]t becomes necessary to look directly and simultaneously at the benefits and risks it
brings, and to make a judgment while undertaking a balanced consideration of those factors.

13Knowledge 7. It is vital to be conscious of the importance of making
decisions and taking action while seeing with your own eyes and thinking
with your own head, , and vital to cultivate such faculties.
Commentary
Japanese Government’s Investigation Committee Report (Final) Chairperson’s Remarks pp.
447-448(7) It is vital to be conscious of the importance of making decisions and taking action while
seeing with your own eyes and thinking with your own head, and vital to cultivate such
faculties.
【Excerpt】
In dealing with an accident or disaster that is beyond the scope of assumption, it isnecessary to have an attitude of thinking for yourself in order to face up to a situation,
and a flexible and active way of thinking. It will be important to undertake organizational
management to boost qualities and faculties such as these during ordinary (nonemergency) times, along with carrying out training and drills.
【Full text】
In dealing with an accident or disaster that is beyond the scope of assumption and forwhich there is no manual to rely upon, the people concerned must consider the various
possibilities based on the information each has at-hand, decide how they should deal withthose possibilities, and take action. In this accident there were many cases in which
inappropriate action was taken, but at the same time there were also a large number ofcases in which people strove to overcome the situation using ingenuity and on-the-spot
judgment, such as gathering together the batteries of cars in the vicinity and using themas an emergency source of power for operating measuring instruments in order to collectthe minimum data in need. Responses such as this were made possible as a result of thepeople concerned thinking for themselves, making judgments and taking actions directed
toward the outcomes they wanted to achieve. To make the optimum actions possible in asituation in which there is nothing to rely on, it is necessary to have an attitude of thinking
for yourself in order to face up to a situation, and a flexible and active way of thinking. It
will be important to undertake organizational management to boost qualities and faculties
such as these during ordinary (non-emergency) times, along with carrying out training anddrills.
Key sentences
 In dealing with an accident or disaster that is beyond the scope of assumption and forwhich there is no manual to rely upon, the people concerned must consider the various
possibilities based on the information each has at-hand, decide how they should deal
with those possibilities, and take action.
 To make the optimum actions possible in a situation in which there is nothing to relyon, it is necessary to have an attitude of thinking for yourself in order to face up to asituation, and a flexible and active way of thinking.

14 It will be important to undertake organizational management to boost qualities andfaculties such as these during ordinary (non-emergency) times, along with carryingout training and drills.

15Knowledge 8. Other: Create an environment for employees to respond inan emergency. Make appropriate public statements and engage inappropriate public relations, and take care also when responding tooverseas inquiries.
CommentaryThis facet of knowledge could also have been incorporated into any of the preceding chapters.
However, it is of a somewhat different nature from the perspective assumed in areas oftechnical expertise on-site. So, out of concern the significance of this knowledge might be lostin the details of the preceding chapters, it has been compiled into a separate Chapter 8.

16

4. Lessons
Lesson 1-1 (Preconditions, occurrence probability, and establishment ofknowledge) (Serial no. 1)
Do not equate regulatory values and design values as conditions sufficient for
ensuring safety, but verify design assumptions and history of the location site, andbear in mind that events exceeding the given conditions, events having a low
probability of occurrence, and events for which knowledge has yet to be established
may also occur.
Precepts
1-1-1 Periodically verify plant design requirements in relation to natural phenomena as
well as preconditions about natural phenomena. (Precept 1)
Commentary: In order to understand the plant’s safety limits, periodically verify design
requirements of the plant in relation to natural phenomena as well as preconditions fornatural phenomena used in design. In doing so, conduct an extensive and thoughtful
exchange of views among specialized areas about the preconditions, relationship tohazards, and other aspects so as to share recognition of risks and link that tocontinuous improvement. Without realizing it, one might unexpectedly and at any time
fall into the trap of assuming that the plant is safe. The operator bears primary
responsibility for any accident and must not believe regulatory or design values to beconditions sufficient for ensuring safety.
1-1-2 Confirm the pre-plant construction topography and foundation as well as
history of any disasters. (Precept 2)
Commentary: The pre-plant construction topography and history of the site has aconsiderable effect on plant design. Confirm the pre-plant construction topography andfoundation as well as the history of any disasters to understand any environmental
weaknesses of the location where the plant is built as well as gain greater insight into
responses to natural phenomena.
1-1-3 Events with a low probability of occurrence as well as uncertain events do
occur. (Precept 3)
Commentary: Events with a low probability of occurrence as well as uncertain events
are things that actually do occur. If you close your eyes thinking that such events will
not happen, that shuts down the thought process. It is important to consider what will
happen if such an event arises. It is particularly necessary to bear in mind that natural
phenomena entail tremendous uncertainty. Be aware of the uncertainties andanticipate cases where events with a low probability of occurrence or uncertain
events happen so as to verify not only the frequency of core damage, but also
whether or not there is potential for cliff edge effects. With regard to natural
phenomena, superposition phenomenon needs to be fully understood. It isnecessary to confirm whether it is possible that common factors in an internal event
may simultaneously result in the loss of function of multiple components.

17

Lesson 1-2 (Learning from incidents and experiences) (Serial no. 2)
In order to respond to a variety of events, actively learn about past incidents andexperiences, and analyze these on the assumption that they may also happen at
your own plant. In addition, always pay attention to international trends as well as
the latest knowledge, and link this information to safety improvements.
Precepts
1-2-1 Endeavor to acquire cutting-edge information about research relating to safety.
(Precept 4)
Commentary: Endeavor to acquire cutting-edge information about research relating tosafety. If opinions are divided, make a judgment about whether the matter is importantfrom the perspective of safety. Although it is difficult to verify everything that is
produced including research papers published by scholarly associations and othergroups, it may be possible to efficiently obtain valuable information by forming tie-ups
with research institutes.
1-2-2 Verify the appropriateness of recurrence prevention measures from multiple
aspects. (Precept 5)
Commentary: Verify the appropriateness of recurrence prevention measures without
being restricted only to the event in question, but by considering safety assurancesfrom multiple aspects. Unless recurrence prevention measures are confirmed to beappropriate, reliably function, and lead to an overall reduction in risk for allconceivable assumptions, they may instead become a hindrance. One effective stepis also to research international trends or, if necessary, conduct extensive discussions
about important issues during international forums and on other occasions.
1-2-3 Extensively utilize your own company’s experiences, other companies’
experiences, and international safety trends in improvement activities. (Precept 6)
Commentary: In improvement activities, make extensive use of not only your own

company’s operating experiences, but also the operating experiences of othercompanies, including those in other countries and other industries as well asinternational safety trends. Nevertheless, it should be kept in mind that there arelimits to disaster prevention measures that only take the form of preventing eventsfrom recurring.
1-2-4 Discern essential threats from cases experienced by other companies andanalyze these realistically as if they may also happen at your own plant. (Precept 7)
Commentary: Discern essential threats to safety from among events that have occurredat your own company as well as other companies, and analyze these on the premisethat they may also occur at your own plant. The essence of the Fukushima Daiichi
accident was the loss of all power sources, which was caused by inundation due to thetsunami. When events occurred in other countries where flooding led to inundation thatcaused power supplied to be lost, it was believed that a tsunami exceeding expectations
would not actually strike in Japan. Therefore, attention was unable to be turned towardlooking for vulnerabilities that might result from inundation.

18

Lesson 1-3 (Assess risks logically) (Serial no. 3)
Endeavor to consider all sorts of elements about your own plant and logically detect
possible risks.
Precepts
1-3-1 Employ workable assessment methods and conduct no-holds-barredcomprehensive risk assessments. (Precept 8)
Commentary: Actively utilize assessment methods which are feasible at the current
stage and conduct comprehensive risk assessments in which nothing is considered
off-limits. Comprehensive risk assessments are a means of finding vulnerabilities in aplant and linking those to safety and disaster prevention measures, but
comprehensive risk assessments are not used to promote the idea that risks are low.
Also, safety goals are necessary for risk management. Confronting all risks,
formulating safety and disaster prevention measures particularly in cases wherethese risks may bring about severe damage, and training to implement thesemeasures may be able to eliminate or mitigate damage. This is risk management
and it ultimately protects not just the organization and its members, but also the livesof residents in the community.

19Lesson 2-1 (Attitude of confronting that which you do not want to see) (Serial
no. 4)
Confirm what the limits of safety are in regard to uncertain events and those with alow probability of occurrence, including terrorism, and honestly accept the results ofsuch assessments. Give priority to incidents where there might be significant
damage, prepare effective countermeasures, and link those to preventing or
reducing any damage that occurs.
Precepts
2-1-1 Confirm the limits of safety in relation to uncertain events and those with a low
probability of occurrence, and implement countermeasures. (Precept 9)
Commentary: Confirm the limits of safety in relation to events involving uncertainty as
well as those with a low probability of occurrence, and, if safety limits are exceeded,
adopt some sort of countermeasures from the perspective of defense in depth.
Uncertainty is inherent in natural phenomena and new knowledge, but, even so, it isimportant to discern the potential for a cliff edge effect. Performance goals need to bepart of the quantitative safety targets for verifying safety limits and, in addition to coredamage frequency, limits need to be also placed on radioactive material releaseamounts. Although everyone recognizes there is no assurance that incidents with a low
probability of occurrence will not rise, human beings tend to think that such events will
not happen.
2-1-2 Give priority to the extent of the damage and prepare effective impact mitigation
measures. (Precept 10)
Commentary: Impact mitigation measures are effective for responding to a variety of
unforeseen severe situations. Do not be inflexible in making determinations by turning
on and off the reasoning typified in the statement: “Financially, the situation is difficult,so we are unable to afford the cost of paying for something that might never happen, oreven if it does, is impossible to forecast the timing of.” Give priority to incidents where
there is likely significant damage and consider effective impact mitigation measures.
With impact mitigation measures, there are also cases where cost is not a substantial
burden.
2-1-3 Honestly accept assessment results and link these to preventing and reducing
any damage that might occur. (Precept 11)
Commentary: Honestly accept assessment results, and link these to preventing or
reducing any damage that might occur rather than looking for reasons not to do
anything. The effort of trying to find a variety of reasons to fit the results within thecurrent safety assessment framework might turn out to be something that puts yourorganization’s very existence in question. In cases where assessment results are harsh,
impact mitigation measures should, at the very minimum, be taken. From theperspective of disaster prevention as well as protecting the organization, it is important
to confirm the limits of safety, prioritize incidents in terms of the magnitude of damage
and difficulty of responding, and then make efforts to prevent or reduce any damage
that might occur.
2-1-4 Coordinate safety and security measures to prepare for a terrorist attack.
(Precept 12)
Commentary: The Fukushima Daiichi accident revealed the vulnerability of a nuclear
20

power plant to terrorism. Terrorism should be regarded as a reality, and dealing withinternal threats is even more serious. Safety and security need to be coordinated andpractical joint training also needs to be conducted with security authorities.

21Lesson 2-2 (Development of a system for reducing omissions) (Serial no. 5)
Assume to the extent possible and, based on the concept of defense in depth,
arrange systems, response procedures, facilities, and other aspects incrementallyaccording to the assumed progression. Systematically develop practicalprocedures for responding as necessary during an emergency and construct an
education and training system for shift crews and emergency responders to acquire
emergency response knowledge and skills.
Precepts
2-2-1 Systematically prepare systems, response procedures, facilities and otherelements based on the concept of defense in depth. (Precept 13)
Commentary: Even though a severe event may occur under any circumstances,
anticipate its progression and systematically prepare systems, response procedures,
facilities, and other elements in an incremental manner. Design basis events entail
uncertainty involved in any assumptions, and preparations are needed to address
events deviating from these. For management of a severe accident (Level 4),
countermeasures need to be considered from a standpoint independent of Level 3(design). Even though assumptions are made to the extent possible, there is the
chance that these assumptions may be exceeded. However, practical applications will
be feasible if we anticipate situations to the extent that they entail very severe
assumptions.
2-2-2 Develop practical procedures systematically for responding as necessaryduring an emergency. (Precept 14)
Commentary: Systematically prepare practical procedures that are closely integrated
with facility design for responding as necessary during an emergency. A system ofpractical procedures will serve as preparation for responding to events exceeding thedesign basis.
2-2-3 Construct a systematic education and training framework so that personnel
may acquire knowledge and skills for emergency response. (Precept 15)
Commentary: Construct a systematic education and training framework for shift
personnel and emergency responders to acquire emergency response knowledge
and skills. The preparation of training materials as well as provision of training andexercises using a systematic approach will make it possible for personnel to develop
the ability to respond to a variety of situations.

22Lesson3-1 (Improvement of facility and system reliability) (Serial no. 6)
Improve the reliability of important facilities as well as telecommunicationequipment so that, even if an unforeseen situation occurs, it will not turn into aworst-case scenario. Also, assess from multiple perspectives whether interlocks
and other safety systems might not conversely increase risk.
Precepts
3-1-1 Consider waterproofing measures and inundation countermeasures when
installing power sources and other important facilities. (Precept 16)
Commentary: Consider waterproofing measures and inundation countermeasureswhen installing power sources and other important facilities. At Fukushima Daiichi,
despite being on a belowground level, power distribution panels, which had been
installed in the basement and subbasement, as well as air intake louvers which wereinundation pathways, and other facilities escaped being flooded if they had been
installed higher than the flood level height. Also, do not forget the installation ofwaterproofing measures, portable power supplies, and other such measures anddevices. When not only tsunami but also typhoons, storm surge, and other suchsevere natural phenomena are considered, inundation countermeasures are essential
in cases where power supplies and other important facilities of a plant located along
the coastline are installed on a belowground level. Also, just because something is on
the first level (ground level) is not reason to feel at ease.
3-1-2 Enhance reliability by improving seismic performance, multiplexing, diversifying,ensuring independence, and other measures. (Precept 17)
Commentary: Enhance the reliability of systems, facilities, and equipment necessaryduring an emergency by improving seismic performance, multiplexing, diversifying,ensuring independence, and other measures. When enhancing reliability, improve thereliability of the system including related equipment as well. When multiplexing
systems, there is a tendency to arrange the systems in positions subject to similar
conditions. Placing equipment in similar conditions means creating vulnerabilities tocommon factors. Reliability is enhanced just by changing the level on which thefacility or equipment is installed.
3-1-3 Diversify telecommunication systems and also consider measures for recovery
of such systems. (Precept 18)
Commentary: Diversify telecommunications systems. Also, consider measures forrestoring telecommunication systems during an emergency disaster. Ensuring themeans to communicate during a disaster is a top priority. Telecommunication systems
may be diversified using pagers, landline telephones, mobile phones, PHS, VHSradio handsets, and other tools, but we tend to forget to consider recovery methods. It
is also necessary to develop communication systems and other tools for use when
wearing full face masks.
3-1-4 From multiple perspectives, assess whether any risks are present in safetysystems. (Precept 19)
Commentary: Assess safety systems from multiple perspectives, considering whether
there are any blind spots in safety systems as well as whether interlocks, valves, and23

other features installed for the benefit of safety conversely increase risk. Verify
premises assumed in safety systems and prepare the necessary impact mitigation
measures along with multiplexing and diversifying.

24Lesson3-2 (Meticulous formation of facilities in preparation for the worst)(Serial no. 7)
Ensure a diverse range of options for emergency response by securing a fullcomplement of spare parts, preparing various adapters for effectively utilizing
support facilities, arranging facility formations in which the operation of key
systems as well as checking of key parameters is possible by human power,
among other efforts.
Precepts
3-2-1 Provide a full complement of spare parts and prepare various adapters for
effectively utilizing support facilities. (Precept 20)
Commentary: Put in place procedures to present requests early on with outside
entities for assistance. Along with securing a full complement of spare parts, ensure
versatility by also preparing adapters for electrical, water, air and other connections toefficiently utilize support equipment provided from outside. It would be very regrettable
if such equipment is provided by external support but is unable to be used because noconnecters are available. It is important to make sure diverse options are available
during an emergency. Also, appropriately implement maintenance management, evenfor facilities and components used during emergencies.
3-2-2 Establish a structure so that human beings are able to operate important valvesand monitor key parameters during an emergency. (Precept 21)
Commentary: Develop a structure so that human beings are able to operate importantsafety solenoid valves, air-operated valves, as well as monitor key parameters, andtake measures, such as placing air cylinders and other necessary equipment andmaterials nearby. Properly keep in mind that, in the end, there will be no choice but tohave these items operated manually by human beings. Also, structure a facility
formation that is equipped with functions such as maintaining equipment open or
closed. Training also needs to be continuously conducted using emergency scenarios
in order to decrease human error.

25

Lesson3-3 (External monitoring as well as firm securing and decentralized
management/control of external facilities) (Serial no. 8)
Be able to quickly verify any external abnormalities. Also, decentralize themanagement of and firmly secure fire engines, portable equipment, heavyequipment, and other items necessary during an emergency as well as facilities
outdoors.
Precepts
3-3-1 Strengthen the emergency response headquarters’ external monitoring
functions and functions for verifying media coverage. (Precept 22)
Commentary: The emergency response headquarters is a sealed room, so install ITV
cameras capable of confirming tsunami arrival and other situations as well as TVs
allowing for confirmation of media coverage. The ability to directly verify the arrival ofa tsunami is effective in an environment cut off from the outside world. Also, if personnel
are unable to go out of the headquarters, it may also be possible that they learn aboutdamage for the first time through TV broadcasts.
3-3-2 Securely fasten outdoor facilities and decentralize management of heavymachinery and other items outdoors. (Precept 23)
Commentary: Anchor equipment outdoors securely to prevent it from falling over due
to earthquake or floating away in a tsunami. So that fire trucks, portable facilities, heavyequipment, and other items, which are set up outdoors and necessary during an
emergency, can be accessed by multiple routes, do not assemble all such items in one
location, but distribute and manage them in a decentralized manner. Also, takemeasures for resupplying fuel.

26

Lesson3-4 (Training to be able to respond to unforeseen situations) (Serial no.
9)
Conduct training in difficult scenarios and severe conditions. Also, establish a
support system in advance with relevant institutions so that support may beeffectively utilized.
Precepts
3-4-1 For training, make use of severe scenarios, such as complex disasters, multiple
simultaneous disasters, etc. (Precept 24)
Commentary: Plan training using complex disasters, multiple simultaneous disasters,
and other severe scenarios, and verify to what extent such disasters can be responded
to using human power. It is also conceivable that there may be a failure or loss offunction due not to a single failure, but to multiple simultaneous failures or common
factors. Also, experts and real-time updatable predictive analytics tools are also
necessary for training in order to correctly comprehend and predict conditions in severe
situations.
3-4-2 For training, develop rigorous configurations, such as a station blackout, loss ofcomputer function, etc. (Precept 25)
Commentary: Conduct training in rigorous environmental conditions, such as in

the dark cut off from AC and DC power, as well as scenarios where computers
are unable to be used. Also, conduct training that entails a high degree ofdifficulty, such as intentionally conveying inaccurate conditions. At ordinary
times, using computers is akin to breathing air. There may also be cases where
personnel do not even realize how dependent they are on computers.
3-4-3 In training, assume a variety of obstacles arise during an emergency. (Precept
26)
Commentary: Although emergency work is necessary to bring a severe accident toresolution, a variety of obstacles develop that hinder emergency work when a natural
disaster or a large-scale accident occurs. To overcome various obstacles to executing
and performing emergency work, there is no other way but to repeatedly conduct
training using scenarios in which impediments are configured, such as intentionallyconveying confusing information, and incorporating delays due to such obstacles.
3-4-4 If part of an organization does not function in the emergency response
framework, replace the missing entity. (Precept 27)
Commentary: During the Fukushima Daiichi accident, off-site centers did not function
and this created considerable confusion. In responding during an emergency onsite, crises are thoroughly managed so that the members of each team of theemergency response system are able to assemble without fail in the day-to-day
management structure. But, in preparation for a situation where part of theorganization goes missing, select personnel, coordinate, and train continuously sothat backup teams may be formed and respond by creating flexibility in themembership of each team.
3-4-5 Agree on a support structure with relevant organizations that includes the specificdetails of support to be provided during an emergency, support procedures, transport
processes, and other elements. (Precept 28)
Commentary: In the case of a nuclear accident, there is a risk of obstacles arising, such27

as the refusal to transport goods to areas contaminated by radiation as well as theinability to exit contaminated areas. Form agreements with relevant organizations abouta support structure, including the specific support to be provided during an emergency,
support procedures, transport processes, and other elements. Nevertheless, in cases
where an accident is combined with a natural disaster, situations may be anticipatedthat make it difficult to bring in equipment and materials for support from outside thearea, and training is necessary assuming scenarios of isolation and helplessness
where, from the onset of the accident, support is unable to be expected from outside or
public fire departments.
3-4-6 Construct a system for receipt of relief supplies that sorts necessary materials
and delivers them to local sites. (Precept 29)
Commentary: During an emergency, there is a rush of relief materials and support

accepted from both inside and outside the country. A system for receiving relief
supplies needs to be constructed that does the work of declaring what is needed,sorting necessary items from the relief supplies, and making sure these aredelivered to local sites. It is important that this type of work is coordinated with local
sites, so such a framework needs to be constructed in advance, which will allow
personnel responding to the accident to concentrate on bringing the accident
under control.

28

Lesson3-5 (Operations with crisis management in mind) (Serial no. 10)
During an emergency situation, anticipate crisis management even for one
operation and ensure alternative measures. In addition, understand the significanceof procedures and do not follow written procedures blindly, but appropriately apply
the procedures and take action.
Precepts
3-5-1 Conduct training where alternative measures are first secured and then theswitchover operation executed. (Precept 30)
Commentary: Predict that an unforeseen situation might occur and conduct training
where alternative measures are first secured and then a switchover operation
carefully executed. Executing a switchover operation is a means, not an objective. It
is important that the objective be achieved even if an unforeseen situation occurs andsecuring alternative measures is significant.
3-5-2 Even in normal times, understand the significance of procedures andoperations, appropriately apply these, and take action during an emergency. (Precept
31)Commentary: Not understanding the significance of operations and implementing

steps according to the procedures during an emergency is likely to lead to amajor error. Even in normal times, conduct education and training that
anticipates emergencies. If operators are familiar with operations during normal
times, they may be able to perform the same operation even during an
emergency. In situations where presuppositions are completely different fromthose held during normal times, the result could be fatal.

29

Lesson 4-1 (Members’ awareness) (Serial no. 11)
Construct a system for training the personnel in whom society places its trust andincrease incentives for improving skills. Each member also needs to be aware of hisor her own role during an emergency, share objectives and basic policies, and takeresponsibility for responding.
Precepts
4-1-1 Conduct training in which trainees cope with scenarios while sharing objectives
and confirming basic policies. (Precept 32)
Commentary: An emergency situation where a variety of events take place one after
another is a situation where responders are overwhelmed with the work right in front ofthem. Training is necessary in which personnel deal with scenarios while sharing
objectives and confirming basic policies so that they are able to make judgments and act
calmly even during an emergency. If responders are aware of objectives and policies, thelikelihood is lessened that they will confuse priorities or degrees of importance even if
external disturbance arises.
4-1-2 Training and competency evaluation systems are needed for understanding
facilities and systems. (Precept 33)
Commentary: So that personnel are able to properly understand plant behavior as wellas properly apply that knowledge and take action during an emergency, training systems
are needed for them to gain an essential understanding of facility and system functions.
In addition, it is necessary to have transparency in guidelines used in training as well as
the qualification system under which operator personnel are commonly evaluated (forstation superintendent, operations officer, chief reactor engineer, etc.).
4-1-3 Understand your own obligations, be aware of the weight of the responsibility,
and take responsibility for your duties. (Precept 34)
Commentary: Build awareness so that all personnel in the emergency response system
maintain a strong sense of responsibility for fulfilling their duties. All personnel should
understand their own obligations, be aware of the weight of that responsibility, andmaintain a strong sense of responsibility in executing their duties. Also, if people whohave not undergone training join the emergency response headquarters, it is necessary
to teach them what their minimum obligations are.
4-1-4 Each functional team surveys the situation to gain an overall understanding andexecutes the necessary support operations in coordination with other teams. (Precept
35)Commentary: Each functional team of the emergency response framework endeavors to
perform its duties, and surveys the situation to gain an overall understanding, arrays therole of its own team within that context, and executes necessary support operations.
Although there are inevitably organizational aspects that must be differentiated according
to specialization, when the top leader issues directions not specified in provisions during
an emergency, that individual shall make clear not just the details, but also the division of
responsibility, and each functional team shall actively cooperate and coordinate so thatno weaknesses manifest in the vertical compartmentalized structure of specialization.

30

Lesson4-2 (Division of roles between on-site headquarters and support
organizations) (Serial no. 12)
In making judgments relating to matters concerning the on-site response, give highregard to the judgment of on-site personnel. The roles played by the head office andother support organizations are to respond to requests for support from the field,
and, from a relatively calm perspective, monitor and assess changes anddevelopments, as well as provide appropriate advice and support.
Precepts
4-2-1 Clarify that judgments about matters concerning the on-site response are to be
entrusted to on-site personnel. (Precept 36)
Commentary: Put in place a framework that expressly specifies judgments about
matters extremely relevant to the on-site response shall be entrusted to on-site
personnel. Support organizations away from the site must not act in a way that holds
back the on-site teams. Only in cases where the head office or another support
organization deems the on-site response to be inappropriate or inefficient should suchorganizations communicate necessary measures to the site. Otherwise, theseorganizations will cause confusion on-site in a way that serves no purpose.
4-2-2 In good faith, on-site personnel shall judge the situation and execute actions to
be taken. (Precept 37)
Commentary: Only personnel on-site have the capability to comprehend conditions in
the field. Share the recognition that the site calmly grasps the degree of urgency, makes
judgments in good faith about the situation, and, while sharing that recognition withsupport organizations as needed, executes the actions that should be taken. The
personnel on-site need the firm conviction to simply dismiss irresponsible intervention
from outsiders.
4-2-3 Clearly define the roles of support organizations. (Precept 38)
Commentary: Clarify that the roles of support organizations are to respond to requests
for support from the site, take an overall bird’s-eye view of the response carried out by
on-site teams, monitor and assess changes and developments from a comparatively
calmer perspective, as well as provide appropriate advice and support. If support
organizations try to do everything as the personnel on-site are doing, then the support
organizations will be unable to fulfill their primary duty. In addition, a support framework
is needed that reviews predictions about how the accident might escalate andsubsequent countermeasures in a manner separate from on-site teams and the head
office response headquarters.

31

Lesson4-3 (The job of the top individual in the hierarchy) (Serial no. 13)
The top leader and executives establish an effective accident response base, andpromptly implement measures in emergency situations that enable the organization
to function in accordance with priorities. Also, when multiple emergency eventsoccur, authority is delegated, dividing up the chain of command to put in place a
flexible system that allows the top leader to think broadly about the situation andcircumstances. The effectiveness of such a system is verified through training.
Precepts
4-3-1 The top leader and executives give priority to measures that enable theorganization to function during an emergency situation. (Precept 39)
Commentary: The top leader and executives should clearly understand the standards
based upon which the organization is committed to accident management and maketheir top priority enabling the organization to function once the shift is made toaccident management. They must not be concerned with their own sense of personal
satisfaction, nor overlook any stagnation in measures that allow the organization tofunction. When an emergency arises, there tends to be a lack of information, butmatters that need to be prioritized must be properly implemented.
4-3-2 The base/stronghold for the emergency response is to be effective in terms ofboth personnel and environment. (Precept 40)
Commentary: When an actual event occurs, there is no other option but to respondwith the most effective system. The organization will simply not be able to do thatwhen form is emphasized over substance, so construct a system that is realistic fortimes of emergency. The base from which the emergency response is deployedneeds to be a location near the site. It must also be a location from which it is easy tofind out what is happening on-site and information is easily attainable to the greatest
extent possible. Also, people are needed who are understand actual conditions. It isnecessary to employ this perspective to verify whether the emergency response
system is realistic.
4-3-3 Authority is to be delegated to divide up the chain of command and allow the
top leader to think. (Precept 41)
Commentary: When multiple emergency events take place, if responsibility iscentered on one person, this presents limitations in the response as importantmatters will be missed. Delegate authority to flexibly divide the chain of command so
as to construct a system that allows the top leader to think. Train repeatedly to verify
the effectiveness of this system. Also, the authority and roles played by the chief
reactor engineer need to be reassessed so that the station superintendent is able to
make full use of the chief reactor engineer from a technical and specialized vantage
point.

32

Lesson4-4 (Communication during an emergency) (Serial no. 14)
Personnel on-site and the emergency response headquarters share a consistentrecognition by, among other efforts, utilizing common templates and communication
tools. The teams on-site check with the emergency response headquarters about
important safety operations that they will perform.
Precepts
4-4-1 Teams on-site check with the emergency response headquarters about
operations that are very important in terms of safety. (Precept 42)
Commentary: Even with operations where judgments are left to the main control room,
on-site teams check with the emergency response headquarters during an emergency
situation about operations that are very important in terms of safety. There is thepossibility a very important safety operation may determine the subsequent direction of
the response, so such response needs to be prudent.
4-4-2 The on-site team (main control room) and on-site headquarters properly share
their recognition and understanding. (Precept 43)
Commentary: In an emergency, the on-site team (main control room) and on-siteheadquarters share a consistent recognition and understanding. If a misunderstanding
emerges about how an important safety facility is perceived, this could result in aserious situation. Effectively using templates and embedding outside responders in theshift teams are regarded as ways to share recognition. If an outside responder is there,
the shift supervisor is able to concentrate on supervising the operators, and this ensuresa timely, accurate, and continuous flow of information.
4-4-3 Be sure to utilize communication tools during an emergency. (Precept 44)
Commentary: Reliably perform basic communication actions during an emergency.
Always try to engage in two-way communication at a minimum or add even moreparties to communication channels during an emergency. This applies to respondingby telephone, reporting, as well as checking on whether any faxes have arrived.
Also, personnel should make it a point in their daily routine not to use misleading
terms. As an example, a Japanese pronunciation of the term manual expressed as“shudo” as used to refer to a manual shutdown (“shudo teishi”) may be easily
confused with the Japanese pronunciation of the term automatic “jido” as used in
automatic shutdown (“jido teishi”), so personnel should make it a point to use thepronunciation “tedo” for manual rather than “shudo.”33

Lesson 5-1 (Attitude toward accommodating new knowledge andenvironmental changes) (Serial no. 15)
To appropriately respond to and accommodate new knowledge and environmental
changes, the top leader spearheads the commitment to fostering a safety culture. If
a safety culture is created, personnel will pay close attention, watching for the
discovery of new knowledge and changes in the environment, humbly listening towhat others are saying, and responding appropriately.
Precepts
5-1-1 In cases where the impact of the latest knowledge or a change in environment is
considerable, promptly link that to continuous improvements. (Precept 45)
Commentary: Strive to collect new knowledge and information about changes in theenvironment, assess the new knowledge and environmental changes from a holistic
perspective, and, if the impact is considerable, do not put off implementing temporary
or mitigating measures. After that, set about considering permanent measures. Even if
new knowledge is gained, it will turn out to be meaningless if reasons are sought for
not accommodating such new knowledge. Assess the magnitude of impact and link
such assessments to continuous improvements in accordance with the level of priority.
5-1-2 The top leader conveys a strong commitment and utilizes reviews and othercritiques provided by outside organizations in order to continually enhance safety.
(Precept 46)
Commentary: The number one priority of the top leader is to recognize risks inherent in
nuclear power and convey values that prioritize safety above all in a way that
demonstrates the individual’s own strong commitment. Also, since the Fukushima
Daiichi accident, the top leader must make everyone throughout the entire organization
aware that, since the accident, society has taken a stricter view of operators, and it isessential for operators not to be complacent and simply meet regulatory requirements,
but strive to enhance safety and, moreover, incorporate reviews and other critiques byoutside organizations into the framework for ensuring safety.
5-1-3 Each individual maintains a stance of questioning and learning, and createsan organization in which there is good communication. (Precept 47)
Commentary: To prevent accidents, build up the level of the safety culture within theorganization and individuals. In addition to an organizational perspective, the roles andduties of each individual in the organization are also important for ensuring safety.
Each individual maintains a stance of questioning and learning, humbly listens to what
others say, and acquires a keen sensitivity to risks. It is important that the individual
freely express his or her views within the organization so that those views are sharedeven with top management and appropriately addressed. Conversely, if you close youreyes to what is happening or try not to look at what is happening, then the company
will eventually face a crisis threatening its very survival.

34

Lesson 6-1 (Culture where discussions can be held facing risks head on)(Serial no. 16)
Share disaster prevention plans and the existence of any risks in handling hazard
materials or other such aspects with the community, and continually adopt
necessary disaster prevention and reduction measures without succumbing to thesafety paradox.
Precepts
6-1-1 Do not get caught up in a safety paradox, but strive to enhance safety. (Precept
48)
Commentary: There is a safety paradox in which the implementation of refinements
leads to a negation of past safety. However, if considered from the viewpoint of thevictim where one’s own family lives in the area, then we find it natural that there bevalue afforded to enhancing safety rather than getting caught up in the safety
paradox. Do not fall for this paradox with regard to safety, but place priority on
enhancing safety.
6-1-2 Disaster prevention plans that take the community residents’ perspective into
account as well as asking the community for its understanding about the control ofhazardous materials and other such aspects leads to a sense of satisfaction andsecurity among community residents. (Precept 49)
Commentary: It is necessary to establish monitoring and other systems that are
helpful for facilitating residents to safely evacuate. It is also necessary to clearly
define the roles relevant organizations play in the community disaster prevention planand gain the community’s understanding. A community disaster prevention plan
begins with sharing with the community the risks entailed in controlling hazardous
materials. Hazardous materials are not simply confined in containers, but there arealso cases where the containers in which such materials are placed rupture, resulting
in a much more serious situation. Ask for the community’s understanding, if
necessary, so that hazardous materials may be properly handled. Discussions withthe community lead to a sense of satisfaction and security among community
residents.
6-1-3 In discussions about safety, eliminate the logic of numbers and the authority
gradient within the organization. (Precept 50)
Commentary: As far as safety is concerned, there must not be a logic of numbers, nor
an authority gradient within the organization. If there is an authority gradient or logicof numbers as concerns safety issues, then no one will attempt to consider safety
seriously any longer. We should reflect on whether we ourselves have maintainedthat an authority gradient is a just and proper aspect of our organization.

Lesson7-1 (Adaptability to be able to respond to the unexpected) (Serial
no. 17)35

It is necessary to thoroughly understand the significance of systems andprocedures and become more adaptable so as to quickly and nimbly makejudgments and take action in response to unforeseen events, as well as possess
the ability to manage that makes it possible to appropriately make use of such
adaptability.
Precepts
7-1-1 Enhance inventiveness that goes beyond following procedures step-by-step.
(Precept 51)
Commentary: There may also be cases of emergency work where environmental
conditions make it such that no manual is able to be used as written. In such cases,
adaptability is needed to be able to piece together several manuals to create a new
manual. This adaptability needs to be enhanced by thoroughly understanding thesignificance of systems and the original manual procedures. This adaptability is notdeveloped simply by following manuals and implementing procedures step-by-step.
7-1-2 Think quickly and nimbly, and make use of all available people and things.
(Precept 52)
Commentary: In system design, an in-depth design will be required that extends
even to the purview of management, and management will be called upon toaddress all areas of defense in depth. Particularly in cases where permanentsystems no longer function, it will be necessary for management to think quickly andnimbly to make use of all available people and things. A comprehensive safetysystem is necessary that ranges from design to management, even including facility
designs and portable equipment, that may be operated with physical strength so as
to make use of the flexibility that human beings possess as well as ensuringcommunication tools and other aspects.
7-1-3 Stipulate in advance workarounds (management) for unexpected work. (Precept
53)
Commentary: Applied operations are naturally not part of procedures, so it is difficult
for the on-site teams and emergency response headquarters to develop a common
recognition and understanding about such operations. There are also cases where,
unless a common understanding is manifest, efforts will also be delayed or become
unsustainable. Although it may be sufficient in an emergency situation to use
workarounds in responding when unforeseen work arises, the management of suchcases needs to be stipulated in advance. Members (particularly the team leaders) ofan emergency response framework must understand their own individual roles aswell as the entire configuration, and provide appropriate information and support tothe person in charge when such management is exercised.

36

Lesson7-2 (Reinforcement of resilience) (Serial no. 18)
Strengthen resilience by continually raising awareness of safety, arranging facility
formations that can utilize the adaptability of people, implementing a system offollowing up throughout the organization, educating personnel to improve skills andknowledge, training under tense conditions, and other means.
Precepts
7-2-1 Train in a manner that contributes to making proper decisions in extreme
situations. (Precept 54)
Commentary: Generally, the training that industry offers does not involve
preparation for making life-and-death decisions, but the Fukushima Daiichi accident
showed us that there are cases where people are forced to act in such a situation.
In addition, even though instructions given in an extreme situation might be correct,
there is always the possibility that the receiver may refuse to do what is directed.
Decision-makers need the ability to calmly make determinations along with thestrength of character to be trusted.
7-2-2 Link safety improvement activities carried out by each and every individual tocontinuous improvements. (Precept 55)
Commentary: Continuous improvement is what bolsters nuclear safety and eachand every individual’s awareness of safety needs to be raised to continuously make
improvements. To raise each and every individual’s awareness of safety, it isimportant to have activities that encourage employees’ awareness of improving
safety on a daily basis and make a steady effort no matter how small the measure
may be. The Great East Japan Earthquake showed us that there is the slightest of
margins between an event turning into a catastrophe or not.
7-2-3 Even in confusing situations, be sure to attend to important facilities within thecontext of the entire system. (Precept 56)
Commentary: Even though people are normally careful, they may forget things in
confusing situations. Such a mistake in relation to an important system may prove
to be fatal, and multi-tiered countermeasures are needed. If the main control room
forgets, the emergency response headquarters must follow up and attend to theactivities at hand, and if the emergency response headquarters forgets as well, thehead office headquarters must follow up, too. Sharing the state of importantsystems within the entire framework and following up for other organizations
becomes a solid step toward resolving the situation. Also, there are two ways ofthinking about how to rank matters in order of priority: one is to prioritize responses
for dealing with matters of great urgency and the other is to be sure to save thatwhich is savable. In actuality, these are combined when responding to situations,but this is done on the assumption that personnel will be sure to keep abreast ofimportant systems.
7-2-4 Bring out people’s adaptability and enhance resilience through training.
(Precept 57)
Commentary: The ability of human beings to adapt to situations is important when37

seeking to address assumptions about the extent of what’s possible. In normal
times, engage in education and training integrating exercises to develop the ability
to adapt so as to augment resilience. For example, it is necessary to establish aframework in which there are systems for delegating responsibility and authority
according to how an event escalates, deploy systems including human-machineinterface capable of utilizing human adaptability, foster a sense of mission among
personnel, train to gain a profound understanding of facilities and the entire system,
as well as conduct exercises in demanding scenarios and drills where a variety of
obstacles emerge under rigorous conditions.

38Lesson7-3 (Develop the temperament and ability to face emergencies) (Serial
no. 19)Develop the temperament and ability to appropriately grasp changing conditions
and degrees of priority, and be able to overcome difficulties such as when special
work is unexpectedly manifested in the severe and fluid conditions of an
emergency.
Precepts
7-3-1 During an emergency, give priority to time factors and adopt a feasible means
within the limited time. (Precept 58)
Commentary: If no more water is fed to the reactor, the temperature of the fuel rods
will exceed 700°C in 2 to 3 hours and there will be a notable increase in the amount ofhydrogen generated in the hydro-zirconium reaction. If water is supplied within 2 to 3
hours after feedwater ceases, it may be possible to prevent a core meltdown. Even ifwater continues to be fed to the reactor, preparations need to be made as thefeedwater may shut down at any time. In such a situation where time is of theessence, it is important that the available means be employed within the limited timeeven if second-best. Even though a certain means may be functionally optimum, if too
much is expected of such a means and time is required to verify conditions andimplement the procedures, the situation may turn critical.
7-3-2 Prepare procedures for work that requires special skills and secure operation
personnel. (Precept 59)
Commentary: In order to respond properly during an emergency, secure personnel
possessing the skills and knowledge to operate heavy equipment and other special
equipment by concluding contracts with partner companies, and construct a system
for training employees. During a disaster, there are cases where work needs to be
performed which employees do not ordinarily carry out. It is necessary to consider
what sort of special skills are required to perform such work, prepare procedures forthat work, and secure operation personnel.
7-3-3 To improve the ability to manage crises, repeatedly conduct training andverification premised on the assumption that a severe situation will actually arise.
(Precept 60)
Commentary: The more severe a situation, the greater the probability for human error,and, without preparation and training, it will be difficult to appropriately respond tosuch situations. Recognize that the temperament and ability applicable to when amajor severe accident arises is not something that may be developed in a short time
during typical classroom training. Repeatedly conduct hands-on education, training,and verification that anticipates a severe scenario. Even if a severe situation isenvisioned, if the scope is limited or an attitude taken that, for example, such asituation will not actually arise, then training or other activities will not improve theability to manage crises.
7-3-4 Appropriately grasp changes in the environment and give priority to making surethat relevant personnel (within the company, country, and overseas) share information.
(Precept 61)

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Commentary: The central government response headquarters, head officeheadquarters, on-site headquarters and the field need to reliably share important
information. Even in poor conditions for communication systems, appropriately graspchanges in the environment and give priority to making sure that information isshared. Sharing information reduces the possibility of misjudgments. Although basic,
this is very important. In addition, the governments of other countries have an
obligation to tell their own citizens residing in Japan about safety measures, andJapan has an obligation to communicate information to the governments of othercountries. No matter what the situation is, the operator should actively endeavor toshare information with the central government.
7-3-5 Anticipate changing conditions and prepare a system for sharing informationthat does not place a greater burden on teams in the field. (Precept 62)
Commentary: In a constantly changing environment, strengthen the monitoring
system in anticipation of any changes, deploy liaison personnel for sharing
information, and establish other such systems. In a situation where on-site teams are
fully engaged in monitoring and operations, there is a tendency to postpone providing
information to the response headquarters. Delays in sharing information make it
impossible to stay ahead of any changes.

40Lesson8-1 (Improvement of the working environment) (Serial no. 20)
Take measures to ensure the safety of employees supporting the emergency
response and ascertain the safety of their families. In addition, establish a systemthat is also equipped for a prolonged response. This will ensure continuity of therecovery work.
Precepts
8-1-1 Protect employees from the disaster and do everything possible to bring theaccident to a resolution with a long-term safety and health management framework.
(Precept 63)
Commentary: Install handrails towards control panels, anchor furniture, personal
computers and other equipment, prevent objects from falling from the ceiling, prepare
helmets, and strengthen other countermeasures against earthquakes and othernatural disasters as well as enhance the long-term safety and health management of
employees. If personnel are critically injured, aspects of the emergency response will
become more difficult to perform.
8-1-2 Establish a system in preparation for a prolonged response that includes water,
food, hygiene maintenance, health management, and other such elements. (Precept 64)
Commentary: Establish a system in preparation for a prolonged response. For
example, give consideration to establishing points where access is controlled forworkers and supplies relayed, as well as measures for stockpiling and resupplying
extra food and water according to the number of personnel on-site, including those
who employed by partner companies. In addition, hygiene management, treatment of
illnesses and injuries, and mental health care are also necessary. It needs to kept inmind that, when an emergency actually arises, there will be more people thanpreviously anticipated gathering on-site.
8-1-3 When an emergency arises, ascertain the safety of the families of responders.
(Precept 65)
Commentary: Construct a framework that maintains morale, such as ascertaining thesafety of the families of responders when an emergency arises. Guidance that
includes checking on the safety of families is particularly necessary to maintain moraleof emergency responders permanently stationed on-site ever since the emergency
arose.

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Lesson8-2 (Public announcements) (Serial no. 21)
In public announcements, aim not to “convey information” but for information to “beconveyed” in a timely and accurate manner. Also, stipulate the manner in which priorapproval is given in cases where urgency is of the essence.
Precepts
8-2-1 Focus on risk communication on a daily basis and aim, when making publicannouncements, for information “to be conveyed.” (Precept 66)
Commentary: In an emergency, appropriately communicate the facts so that people
have a proper fear of the risks. Choose and supplement your words so that there is no
misunderstanding. Think through to how what you say will be understood by thelistener before you speak. Expressions that leave judgments up to the receiver are notappropriate. In addition, refraining from making public statements or embellishing facts
under an excuse such as “it is necessary to do so in order to avoid confusion” will leadto a loss of trust, which is the most important thing to maintain. It is more important for
information “to be conveyed” than “to convey” information, and it is particularly
necessary to pay attention to statements that might be interpreted as evading
responsibility. It is also important to practice risk communication on a daily basis sothat information is properly conveyed.
8-2-2 Reach an agreement within the organization and among relevant organizations on
improving the efficiency of preliminary understandings during an emergency. (Precept
67)
Commentary: In cases where conditions change from moment to moment, strive tocommunicate timely and accurate information. There may also be cases where
urgency is of the essence, so efficiently obtain prior understanding internally or withother organizations. It is important to share information with upper organizations andrelevant organizations. However, if all press releases need the prior consent of theseorganizations, there is a danger of creating a situation where urgent information
concerning the health and lives of residents is unable to be immediately released
publicly.

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Lesson 8-3 (Public relations) (Serial no. 22)
Set a policy for accommodating visitors whose visit to the power station during an
emergency is unavoidable.
Precepts
8-3-1 Minimize accommodation of visitors that are obligated to come to inspect orenter the station during an emergency. (Precept 68)
Commentary: In cases where inspections or visits during an emergency absolutely
cannot be refused, have visitors understand their arrival is preconditioned on theassurance of safety so as to minimize accommodating visitors. In preparation for avisit that is unavoidable during an emergency, verifying in advance that a standard
for accommodating such cases has been safety established will be useful inminimizing confusion during actual visits.
8-3-2 In cases of humanitarian public relations, place top priority on ensuring thesafety of the visitors. (Precept 69)
Commentary: Cases may also be anticipated where humanitarian public relations
are accommodated. In such a case, place top priority on ensuring visitors’ safety andaccommodate them flexibly. If a variety of scenarios are anticipated, staff will not berushing around making preparations, so any impact on the emergency response may
be minimized.

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Lesson 8-4 (International relations) (Serial no. 23)
Understand international rules so that no international friction is created. Also,
appropriately provide information to foreign governments.
Precepts
8-4-1 In cases where there are differences between international rules and nationalrules, ascertain clearly what those differences are. (Precept 70)
Commentary: If there are differences between international and national rules, thenascertain clearly what those differences are. Care needs to be taken as
announcements by international institutions have an impact and are broadly cited inmedia reports as well as other publications and broadcasts.
8-4-2 Ascertain the necessary procedures regarding measures for dealing withhazardous materials and other events that might emerge as an international issue.
(Precept 71)
Commentary: Ascertain in advance what sort of procedures are necessary as concerns
events that could become an international issue. In normal times, there is a tendency
to overlook international arrangements as not posing any particular issues, but avariety of activities will get underway outside Japan when a disaster occurs.
Unnecessary confusion may be avoided by ascertaining international frameworks andmethods for dealing with the hazardous materials in question.

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