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©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.
Current Status of Fukushima Daiichi Nuclear Power Station& Lessons Learned from Experiences of the Great East Japan
Earthquake at Fukushima Daini Nuclear Power Station
These materials may contain sensitive information from TEPCO or other companies. Therefore, the usage of these materials outside of their intended goal is prohibited, alongside the showing or publication of these materials to third parties. TEPCO
July 18, 2016 @ Ottawa, Canada
Naohiro MasudaManaging Executive Officer
Fukushima Daiichi D&D Engineering Company PresidentChief Decommissioning Officer
Tokyo Electric Power Company Holdings, Inc.(Former Site Superintendent of Fukushima Daini Nuclear Power Station)
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.
Fukushima Daini NPS
Name: Naohiro MASUDA
Education: •B.S. in Electrical Engineering, Yokohama National University, 1980•Master’s Degree in Electrical Engineering, Yokohama National University, 1982
Experience:•Started the career as an electrical and I&C engineer at the Fukushima Daini NPS (2F) in 1982 and was in charge of Unit 2-4 construction works
•Manager of Electrical and I&C design group, Headquarters in 2000
•Plant manager at 2F site, 2005 through 2008
•Site superintendent at 2F site, 2010 through 2013, and achieved the successful recovery of all the 4 units responding to the earthquake and tsunami on March 11, 2011
•President of Fukushima Daiichi Decontamination and Decommissioning Engineering Company (FDEC), and Chief Decommissioning Officer since April 2014
Introduction
1
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.
Map of Japan and location of Fukushima Daini NPS
Fukushima Daiichi NPS
Fukushima Daiini NPS
J-village
2
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.
Fukushima Daini NPSCurrent Status of Fukushima Daiichi
Nuclear Power Station
3
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 4
State of Fukushima Daiichi Units 1~4
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 5
Sea Area MonitoringConcentration of Radioactive Materials has been Gradually Decreasing
Sea-SideImpermeable
Wall
Regulation Limit・Cesium 137: 90Bq/L・Cesium 134: 60Bq/L
Bq/lCompletion of Seaside
Impermeable Wall Closure(Oct 26,2015)
North of Units 5&6 Discharge Outlet
Bq/l
Front of Shallow Draft Quay
Near South Discharge Outlet
In Front of Unit 1-4 water-intake
Completion of SeasideImpermeable Wall
Closure(Oct 26,2015)About one-millionth compared with the one after the accidentOutside port are substantially below regulation limit
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 6
Worker Security and Improved Work Environment
Large rest house
Currently, more than 90% of orders fulfilled by negotiated contracts, which enables contractors to secure workers in a long term.
Number of workers per weekday (TEPCO employees and contractors) engaged in work during March assumed as approximately 6,390 people.
Percentage of locally born workers approximately 50% in Jan.
Large rest house with a capacity of approx. 1,200 workers (from May 2015)
→Convenience store “Lawson” opened on March 1, 2016New office building close to the field (from 2014)
Fukushima Revitalization Meal Service Center(from March 2015)
• Providing warm meals to Fukushima Daiichi
• Creation of employment opportunities
• Dispelling harmful rumors about Fukushima food
Changes in number of workers Improving work environment
Ensuring stable long-term employment
Trend of monthly exposure dose rate
Change in the average number of workers (actual value) per weekday in the months following 2013.
Efforts being made to secure personnel over long term while managing amount of worker radiation exposure.Further efforts made for continuous improvement of work environment while understanding worker needs.
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 7
Fuel Removal from the Spent Fuel Pool (Unit 4)
September 22, 2011 July 5, 2012
Process of removing fuel rods at SFP Unit 4
November 12, 2013: Completion of building steel framework (The volume of steel used is equivalent to those of Tokyo Tower.)
Fuel removal started on November 18, 2013Removal of 1535 fuel bundles completed on December 22, 2014 as scheduledNo risk from fuel remains at unit 4. This gives confidence to proceed to fuel removal at
units 1, 2 and 3
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.
Fukushima Daini NPSLessons Learned from Experiences of the Great East Japan Earthquake at
Fukushima Daini Nuclear Power Station
8
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 9
Response after the tsunami-- Recovery Actions toward Cold Shutdown --
1. Plant status• Plants “shutdown” safely• Loss of “cooling” function: pumps and motors on the sea side• Possible failure of “confining” function (PCV)
2. Strategy• Restoration of cooling function
3. Actions• Check equipment operability Walkdown on the sea side• Prioritize restoration targets• Replace motors, laying cables
4. Cooling function restored5. Cold shut down and keep that status
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 10
For Further Enhancement of SafetyRobustness
Improve robustness to decrease risks against external events
ResilienceImprove capability of flexible and efficient response
“Even if we have a flat tire, spare tires and tools are available, and the personnel have the skills to use them in order to replace the flat tire themselves”.
Safety Goals to minimize social impactFilter vent to minimize contamination
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 11
Recovery Actions toward Cold Shutdown• Walkdown to identify damage of equipment (Midnight, March 11)
• Under continuous tsunami alerts, walkdown must be done in the field where a lot of debris, openings and flooding areas existed in the dark.
• Emergency procurement of materials and equipment (March 12)• Emergency procurement of motors, cable, mobile power vehicles, fuel
oil and mobile transformers with close cooperation between site ERC and corporate ERC.
• Equipment and power restoration work in the field (March 13)• Motors were replaced.• Temporary cables were laid to supply power from undamaged power
cubicles.• Temporary cables of 9 km length were laid by about 200 employees
within a day.Usually this size of cable laying requires 20 employees and more than 1 month period.
Reactor cooling started with restored RHR pumps (March 14)
Procurement of Power Supply Vehicles
Replacement of a motor
Temp. Cable Laying
Various efforts enabled us to achieve cold shutdown at all units at 7:15 on March 15th, 2011.
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 12
Countermeasures reflecting the lessons learned from our restoration activities after the tsunami and the accident in Fukushima Daiichi
Debris on the road
・Enhancing emergency response capability ・Making routes for emergency response by
operating heavy machines by ourselves
Loss of Power Supplyand Cooling Function
・Staging spare motors, cables etc.・Deployment of power vehicles and GTG vehicles・Increase of operational speed with improved skills
Station Black Out・Deployment of power vehicles and GTG vehicles・Training site personnel for restoring power
Loss of cooling and water injecting functions
・Stand by fire engines as water injection ・Training site personnel for water injection
Lessons learned fromFukushima Daini
Lessons learned fromFukushima Daiichi