Decommissioning at Fukushima-Daiichi NPP at Fukushima-Daiichi NPP ... (October 2014) Fuel removing cover (Image) Roof Crane ... (FHM) Cask pit

All Rights Reserved 2015 The Tokyo Electric Power Company, Inc.
4 MAR 2014, Fukushima-Daiichi NPP (Source : Nikkei Inc.)
Decommissioning at Fukushima-Daiichi NPP
Takafumi IHARA

All Units maintain cold shutdown
RPV bottom temp. PCV internal temp. Fuel pool temp.
Unit 1 ~17 ~17 ~13
Unit 2 ~21 ~22 ~30
Unit 3 ~20 ~19 ~20
Unit 4 No fuel, so monitoring not requiredNo fuel, so monitoring
not required~9
Values as of 11:00 on January 11, 2016
1

! About one-100 thousandth compared with the one after the accident
! Outside port are substantially below notified concentration.
36 6
36
,
1 ,
0536 -, -
36
- 1-,
36 26
36
26
6
[Regulation limit] Cesium 137: 90 Bq/L Cesium 134: 60 Bq/L
Concentration level of radioactive materials in the sea
"The concentration level has been gradually decreased
15 km off the coast of NPS (Bq/L)
Sea Water Inlet at unit 4 (Bq/L)
Discharge outlet (South) (Bq/L)
Mar 2011 Oct 2015
May 2011
Oct 2015
Apr 2011 Sep 2015

" TEPCO continuously collects information from all contractors and arrange to assure the necessary number of workers for expected works
Number of workers
3
Average worker in weekday (man/day)
Month
(May,&2015)&
FY&2013& FY&2014& FY&2015&

Present Status
Water Inventory Issue
Decommissioning Roadmap
Improvement on work environment
Roles and responsibility among organizations for decommissioning
Main Contents
4

Present Status
5

Progress Made at 1F Unit 1
Remote-operated boat and robot identified leakage locations in torus room
Reactor Building (3/15/2011)
Reactor Building Cover (installed in Oct. 2011)
Torus Room (5/27/2014) Torus Room (11/13/2013)
6

Progress Made at 1F Unit 1 (contd)
Robot identified leakage from expansion joint of vacuum breaker piping (5/27/2014)
7

Reactor building are being dismantled in preparation for fuel removal
8

(Ref) Procedure of dismantling Unit1 building cover
Mitigation measures against dust dispersion are being conducted while building cover is dismantled. All the roof panels have been dismantled (5 Oct. 2015)
FY 2016 FY 2017 FY 2015 FY 2014
Rubble removal
Installation of fuel handling support etc.
Dismantling building cover
9

Conditions of the top of operating floor Reactor building cover removal
(October 2015)
"Building cover removal is in progress taking measures against dust stirring and of decontamination and shielding on the floor
"Many rubbles on the operating floor will be removed "Finally, the deck and fuel handling machine will be installed
Overview of refueling level (June 2012)

Rubble
Ceiling crane
Picture 1
Picture 2
Picture 3
Surface of fuel spent pool
Cover of reactor well
Ceiling crane
Cover of reactor well

Gamma Camera Image of Refueling Floor (2/21/2013)
Blow-out Panel Closed (3/11/2013)
Steam Coming Out From Blow-out Panel (4/10/2011)
Video images obtained inside primary containment 12

Robot retrieved core samples from refueling
floor (3/21-22/2014) 13

Spent Fuel Pool (2/14~18/2013)
Rubble Removal in Progress (5/29/2013)
Crippled Reactor Building (3/15/2011)
Robot found leakage location in reactor building 14

Rubble in spent fuel pool being removed by remote operation
15

Before large debris removal (March 24, 2011)
N
After removal of large debris
N
(April 19, 2014)
Rubble removal toward fuel removal from SFP in Unit 3 (1/2)
Installation of fuel removal cover and fuel handling facility planned Due to high radiation levels, dose reduction measures must be carried out safely and steadily with remote-controlled heavy machinery.
Current
Status tasks
" ALARA is kept in the Decontamination and shielding works " The taget of dose exposure for fuel removal is less than 1mSv/h
16

Decontamination work completed
"The dose rate on the Unit 3 refueling floor is high "Decontamination work is being conducted with remote-
controlled heavy machinery and decontamination devices.
Rubble collection device Suction device
Cutting device
Used for the collection of small debris
Used for suction removal of small debris and dust, etc.
Used for cutting the surfaces of concrete Decontamination work partially
completed
Unit 3 refueling floor
Decontamination toward fuel removal from SFP in Unit 3 (2/2)
17

(Ref) Dose difference between Unit 4 and 3
Measured : ~February 2014
18

(Ref) Dose difference between Unit 4 and 3 (contd)
19
Unit3 Reactor Building 5F

Current Condition (May 2014) Photo Damage to concrete surface
Photo Condition of north side of R/B
Photos Photo
(Ref) Unit 3 Refueling Floor (Significant Damage Sustained)
20

Preparation Status for Fuel Removal Cover at Unit 3
! Cover components including steel frame and girder were made and transported to the Onahama Port, more than 50 km away from 1F.
! Once assembled there in order to confirm working procedure ! Module partially assembled there will be transported to reduce
working hours and occupational dose at site
Removal of Fuel Handling Machine from SFP
(Aug. 2015)
Assembling work at Onahama Port (October 2014)
Fuel removing cover (Image)
Roof Crane
Fuel Handling Machine
Cover for removing fuels

Concrete wall
Water Injection by Concrete Pumper (3/22/2011)
Fuel Removal from SFP (11/18/2013~)
Spent Fuel Pool Structure Reinforced
(7/30/2011)
S t e e l Pillars
22

On-site transporting cask
Crane
Fuel removal from SFP in Unit 4
On-site transport
Spent fuel pool (SFP)
Fuel removal cover
Cask pit Ensuring
empty space.
Fuel handling machine (FHM)
Cask pit
Fuels have been removed since November 18, 2013. 1533 fuels was stored inside SFP at the time of starting fuel
removal.
Common pool (on site)
23

Fuel removal from SFP in Unit 4 (contd)
Status on Sep.22,2011 Removal of PCV head (July 2012)
Construction of cover flame (Jan. ~ May 2013)
Complete the Fuel removal facility cover (Oct. 2013)
Fuel removal work started (Nov. 18. 2013)
Rubble removal on 5th floor of R/B (Mar. 2012)
"Construction period: 11m (From steel flame erection to commence of Fuel Removal) "Gross weight of newly installed facility: approx. 4,900 ton
24

Present Status
25

Inflow Approx.

Decommissioning at Fukushima-Daiichi NPP at Fukushima-Daiichi NPP ... (October 2014) Fuel removing cover (Image) Roof Crane ... (FHM) Cask pit

Documents