current status of fukushima daiichi nuclear power...

©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

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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)


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


Map of Japan and location of Fukushima Daini NPS

Fukushima Daiichi NPS

Fukushima Daiini NPS

J-village

2


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


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


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.


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


Fukushima Daini NPSLessons Learned from Experiences of the Great East Japan Earthquake at

Fukushima Daini Nuclear Power Station

8


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


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


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.


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

current status of fukushima daiichi nuclear power...

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