Analysis on human and organizational factors regarding initial - PowerPoint PPT Presentation

Analysis on human and organizational factors regarding initial responses of shift teams and field workers to the Fukushima Daiichi NPP accident TECHNICAL MEETING ON MANAGING THE UNEXPECTED — FROM THE PERSPECTIVE OF THE INTERACTION BETWEEN INDIVIDUALS, TECHNOLOGY AND ORGANIZATION 25–29 June, 2012 IAEA Headquarters Vienna, Austria Hiroko KOIKE Takaya HATA Ryuji KUBOTA Japan Nuclear Energy Safety Organization (JNES) 1

Table of Contents 1.Introduction 2.JNES classification 3.Investivation approach step 1 : Make a chronology of event step 2 : Identify the problems related to human errors step 3 : Identify direct causes step 4 : Identify human and organizational factors 4.Results of approach 5.Conclusion 2

1. Introduction • JNES has developed taxonomy of human factors and “JNES Organizational Factor List” named JOFL. These are event analysis tools for DCA and RCA. A purpose of them is to review PSFs, good practices and lessons learned to be reflected to the regulatory activity. • • JNES analyzed on human and organizational factors JNES analyzed on human and organizational factors regarding initial responses of the shift teams and field workers to the Fukushima Daiichi NPP accident in order to improve these analysis tools. DCA : Direct Cause Analysis RCA : Root Cause Analysis PSFs : Performance Shaping Factors 3

2.JNES Classification We use two classifications: - Taxonomy of Human Factors - The classification of Organizational Factors named JOFL Factors named JOFL 4

Taxonomy of Human Factors Organizational Workplace Factors Task Factors -Team structure/organization - Task difficulties -Inadequacies in instruction and supervision - Work load inadequacies -Communication - Working time inadequacies -Team work / Workshop moral - Parallel / Unexpected tasks -Compliance Site Environmental Individual Factors Conditions Factors -Psychological stressor -HMI inadequacies -Physiological stressor -Work place inadequacies -Subjective factors Administrative -Work condition inadequacies -Work performance incapability Factors -Special equipment -Education and training -Provisions/Procedures Human Factor -Regulation/Work planning Organizational Factor 5

JOFL classification Key factors No. Intermedeate classification No. 1 1-1 economic status External Environmental Factors 1-2 regulatory response policy external communication 1-3 general reputation 1-4 2 Organizational Psychological Factors 2-1 organization climate 3 3-1 top management commitment Operational Management Factors 3-2 organizational administratin 3-3 human resource management 3-4 company policies and compliance criteria / standards 3-5 communication between head office and power station 3-6 self-evaluation (or the third party evaluation) 4 4-1 division-manager level organization administration Intermediate Management Factors 4-2 conformance to rules 4-3 continuous education of organization 4-4 personnel management 4-5 communication 4-6 procurement management 4-7 human resources management related to organizational structure 4-8 engineering control 4-9 work control 4-10 change control 4-11 non-conformance control 4-12 corrective action 4-13 documentation control 5 5-1 inter/intra-party communication Collective Factors 5-2 knowledge / education groupthink and decision-making based on principle of individuality 5-3 such as a senior manager 6 6-1 knowledge / skill Individual Psychological Factors 6-2 leadership 6-3 ambitiousness / carefulness for safety 6-4 ambitiousness for management 6 6-5 concern about field staffs 6-6 motivations, stress

3.Investigation approach Reference material Step 1 : Make a chronology 1.TEPCO’s Report of event 2.The Interim Report of investigation Committee on the Step 2 : Identify problems Accident at Fukushima Nuclear Power Stations related to human errors 3.The proceedings of the Fukushima Nuclear Accident Step 3: Identify direct causes Independent Investigation Commission (NAIIC) 4.Press release which the Step 4: Identify human and regulatory body and our group organizational factors conducted the on-site investigation. 7

Step1:Main Sequence of the accident of Fukushima Dai-ichi NPS (Friday,11 March) (1) The manual 14:46 Loss of external power stopping of IC supply due to earthquake at Unit 1 Core cooling system not using AC power (2) Switching off 14:47 Start-up of emergency (Unit1:IC(isolation condenser), Unit2: RCIC(reactor power generation the HPCI core isolation cooling system), Unit3: RCIC and HPCI (high pressure core injection system) system 15:37 ～ ～ ～ 15:42 All emergency ～ manually at manually at Stop of core cooling system Stop of core cooling system diesel power generators Unit 3 not using AC power stopped except for one (3) Insufficient generator in Unit6 due to recovery tsunami During this time without activities cooling, the fuel was exposed 15:37 related to and core melt started, Loss of all AC power supply generating hydrogen power-supply except for Unit6 And vehicles and Loss of DC power supply fire engines. Alternative water injection For Unit1,2 from a FP line after decreasing (Unit 5 took power supply from Unit6 on 13 March). RPV pressure 8

Investigation approach Step 1 : Make a chronology of event Step 2 : Identify problems related to human errors Step 3: Identify direct causes Step 4: Identify human and organizational factors 9

Step2: (1)The manual stopping of IC at Unit 1 (Friday, 11 March ) -15:03, The return pipe isolation valves(MO-3A,MO- 3B) of the IC were fully closed. -17:50, An operator found the indication lamps of MO-3A and MO-2A were closed state. -18:18, An operator performed the opening action of MO-3A the opening action of MO-3A and MO-2A . -18:25 , Considering that the piping needed to supply water for the shell side had not been formed, an operator set the return pipe isolation valve Problem No.1 (MO-3A) to a “closed” state . Lack of knowledge of IC functions and lack of experience in its operation 10

Step2:(2)Switching off the HPCI system manually at Unit 3 Main Steam Line 11 March CST -16:30 ,Reserve the reactor water Turbine level by using the RCIC and Stop Valve RPV the HPCI 12 March regulating -Alternative spraying of the S/C Control valve of flow using DDFP was studied. -12:35 HPCI started up PCV automatically (reactor water automatically (reactor water Problem No.2 level low). Supply Water Source Minimum flow Steam Line A failure to reduce pressure 13 March water Bypass valve Switching Line -02:00 ,The reactor pressure that of the RPV for the alternative system had remained stable at approx. water injection method using Minimum flow line 1MPa began to decline. the FP system, etc. after -02:42, An operator halted the switching off the HPCI HPCI. Injection line system manually at Unit 3. Suppression -02:45, DDFP had failed. Chamber As a result, water level went HPCI system diagram down, and the core was exposed. 11 DDFP: diesel-driven fire pump

Step2:(3)Insufficient recovery activities related to power-supply vehicles and fire engines Date Time Event Problem Site Superintendent ordered staff to study a method for 11-Mar 17:12 water injection through the FP line through fire engines. Licensees and workers from a contractor company started Before 12-Mar dawn clearing debris to find the outlet of the FP line . of the FP line . The power generation team and fire Problem No.3 brigade headed for the target area to Insufficient recovery find the outlet of the FP line outside activities related to fire the building. 2:00 Several operators who had been engines for water refueling the DDFP with light oil joined injection services. the work teams to find the outlet of the FP line, but were unable to do so. 12

Step2:(3)Insufficient recovery activities related to power-supply vehicles and fire engines Date Time Event Problem It was confirmed that one initially Problem No.3 11-Mar 22:00 dispatched HVPS car had arrived at the Power Station site. Insufficient recovery activities related to It was confirmed that 72 HVPS 10:15 cars had arrived at Fukushima power-supply vehicles for NPS. power source restoration A backhoe was used to clear obstacles that had washed onto work 13-Mar the road before parking a HVPS car. A backhoe was used to clear obstacles that had washed onto the road before parking an HVPS car. To reserve a cable laying route, the team requested a contractor to fetch compressed gas cylinders stored at the technical training facility in the Power Station site. The team then used the cylinders to fuse the closed shutter of the bulk delivery entrance of Unit 3 Turbine Building and the deformed fire door at the walk through of the control building between HVPS: High Voltage Power Supply 13 Units 3 and 4.

Investigation approach Step 1 : Make a chronology of event Step 2 : Identify problems related to human errors Step 3: Identify direct causes Step 4: Identify human and organizational factors 14