Japan Nuclear Technology InstituteConfirmed as of 8:30 on December 21, 2011

Status of Fukushima Daiichi Nuclear Power Station
Unit-1 GE BWR3460MWe
Mark-I PCV(*)
Operating since 09/27/2010

Unit-2 GE/Toshiba BWR4784MWe
Mark-I PCV(*)
Operating since 11/18/2010

Unit-3 Toshiba BWR4784MWe
Mark-I PCV(*)
Operating since 09/23/2010

Reactor status: Auto shutdown
Fuel damage
Reactor water level as of 12/20 12:00
Fuel area: －/ -1850mm
Reactor pressure as of 12/20 12:00
0.100/ - MPa abs (*1)

Reactor status: Auto shutdown
Fuel damage
Reactor water level as of 12/20
12:00
Fuel area: －/-2122 mm
Reactor pressure as of12/20
12:00 0.106/ - MPa abs (*2)

Reactor status: Auto shutdown
Fuel damage
Reactor water level as of 12/20
12:00
Fuel area: -2077/-2243mm
Reactor pressure as of 12/20 12:00
beneath the range
Feedwater nozzle temperature
12/20 12:00 54.6ºC

PCV(*) status: Pressure as of 12/20 12:00
0.1101 MPa abs
10/9 17:07 – 22:30
Cutting a pipe in the RPV spray to install agas controlling system

Core decay heat removal
6/27 16:20 Began using water processed atwater processing system alongside injection
from filtered water tank for reactor injection
11/30 16:04 Started nitrogen injection to theRPV
12/10 10:11 Started water injection from CS(*)
system to the reactor
12/19 18:00 Started regular operation ofPCV(*) gas controlling system
As of 12/20 11:00 Injecting processed water tothereactor
pressure
vessel(FDW(*):4.5,CS(*):2.0 m3/h)
8/10 11:22 Began full-scale operation ofSFP(*) alternative cooling system
SFP(*) temperature: 12/20 12:00
12.0℃
SFP(*): Stored units/capacity
292/900

10/28
Completed installation of the cover for theReactor Building(*1) 6/4 11:00 onward Calculated absolutepressure using temporary measurement
device value, recorded in place of channel A(*2) 6/24 20:00 onward Calculated absolutepressure using temporary measurement
device value, recorded in place of channel A

PCV(*) status:
Pressure as of 12/20 12:00
0.111MPa abs
10/28 18:00 Putting gas
management system of thereactor containment vessel inoperation.
Adjusting the amount of
injecting nitrogen gas to thePCV(*),regarding the hydrogenconcentration
Core decay heat removal
6/27 16:20 Began using water
processed at water processing
system alongside injection fromfiltered water tank for reactor
injection
11/2 Start injecting boric acidwater because of the possibilityof fission reactions by theradionuclide gas analysis.
11/30 13:45 Started nitrogen
injection to the RPV
As of 12/20 11:00 Injecting
processed water to the reactor
pressure vessel (FDW(*):2.8,
CS(*):6.0m3/h)
11/6 Sta rte d op era ti on o fSFP( *) ra di oa cti v e ma t eria ldeconta mina tion instru ment
SFP(*) temperature: 12/20 12:00
15.5℃
SFP(*): Stored units/capacity
587/1240

PCV(*) pressure:Pressure as of 12/20 12:00
0.1016MPa abs
7/14 20:01 Began nitrogen sealing
Core decay heat removal
8/31 ～ 9/1 Flexible hose wasinstalled and started water injection
into the reactor
11/30 16:26 Started nitrogen
injection to the RPV
As of 12/20 11:00 Injecting processed water
to the reactor pressure vessel(FDW(*):2.8,CS(*):5.9m3/h)

6/27 8:08 – 14:38 Temporarily
switched core injection pump
power source for Units-1 through3 to Diesel Generator (due toOkuma power line 2 restorationwork)

Unit-5 Toshiba BWR4784MWe
Mark-I PCV(*)
Outage since 01/03/2011

Unit-6 GE/Toshiba BWR51100MWe
Mark-II PCV(*)
Outage since 08/14/2010

Plant Status

Reactor status: Outage
All fuels removed

Reactor status: Outage
Fuel loaded
RPV head installed
Reactor water level as of 12/20
12:00
Stop range: 1788mm

Reactor status: Outage
Fuel Loaded
RPV head installed
Reactor water level as of 12/20
12:00
Stop range: 2102mm

Application of Article 15 of theNuclear
Emergency
Preparedness Act
Units-1, 2 and 3

Core decay heat removal
Cooling
6/24 16:35 Began cooling SFP(*)
using FPC(*)
SFP(*) temperature: 12/20 12:00
16.7℃
SFP(*): Stored units/capacity
946/1590

Core decay heat removal
CoolingSFP(*) temperature: 12/20 12:00
16.0℃
SFP(*): Stored units/capacity
876/1770

Core decay heat removal―12/20 11:00 SFP(*) temperature:20ºC(temporary thermocouple
measurement value)
5/9 onward Began work to install
SFP(*) bottom support structure
7/31 12:44
Performed full-scale operation ofSFP(*)
alternativecoolingsystem8/20 11:34 Full-scale operationof the desalination device wasstarted
8/31 Water was found in theSFP(*)’s liner drain
SFP(*): Stored units/capacity
1331/1590
Currently taken out 548

7/1 10:00 Began transferring
puddle water in basement ofturbine building from temporarytank to mega float

7/1 11:00 Full-scale operation ofSFP(*)
alternativecoolingequipment
SFP(*) temp. as of 12/20 12:00
13.3ºC
SFP(*): Stored units/capacity
514/12207/18 8:30 Began installing
temporary roof onto turbine
building

10/28 Started installation
work of the water shielding
wall at the seaside

10/7 14:06～ water spraying in theplant site using the treatedaccumulated water of unit5,6Units-1-6 Common SFP (*)
Stored units/capacity
6375/6840
3/24 18:05 Cooling started
7/18 6:00 Confirmed pool water level
was maintained
12/20 10:00 Temperature around
16℃

Resident evacuation
4/21 Prime Minister instructs
establishment of warning area
for area within 20km radius;
access restriction and/orevacuation
4/22 Prime Minister lifts theinstruction of staying-indoorsfor 20– 30km radius, establishes
planned evacuation &emergency evacuation prep.
areas and instructs all to comply
with these measures
Maximum on-site dose rate:
3/15 400mSv/h4/23 17:20 Current survey mapof 1F announced
Worker exposure:
As of 6/27 0:21 Cumulative total ofworkers with over 100mSv of external
exposure during emergency work:
30 workers
8/1 14:30 Confirmed over 10 Sv/h ofpipe surface dose rate near the standby
gas treatment system pipe joint at themain stack bottom of Units 1 and 2

7/26 – 27 Performed site
confirmation, dosage investigation
with robots and employees

6/13 10:00 Began full scale operation of recirculating seawater
purification equipment installed in Units-2, 3 screen areas
6/18 10:00 – 6/20 around 10:00, 6/25 10:00 onward
Temporarily halted due to maintenance

7/22-24
Dust sampling overreactor buildings atUnits-1 through 3 via
unmanned helicopter

Unit-4 Hitachi BWR4784MWeMark-I PCV(*)
Outage since 11/30/2010

Reception of off-site power supply
3/20 19:52 Units-5, 6 startup transformer power reception
3/24 15:37 The Common SFP(*) received external power
5/11 15:20 Power for Units 1 and 2 partially received from Okuma Power Line2.
5/12 15:20 Switched Unit-4 and common SFP(*)480V power supply panel
from Okuma Line 3 to Tohoku Electric Power Company Nuclear Line (66kV)
7/11 Started up and made synchronized D/G for Units-5, 6 due to dual-line
preparation work for Yoru no Mori power lines
6/19 19:30 – 23:45, 6/20 10:25 – 14:50 Conducted trial water sending using
highly radioactive contaminated water of cesium adsorption unit
6/24 12:00 Began processing via water treatment facility fresh water processing
unit
8/19 19:41 Started operation of the 2nd cesium adsorption instrument, andparallel operation
12/4 around11:33 Found that there was puddle water inside the barrier aroundthe evaporative condensation apparatus, piled sandbags around the gap and inthe gutter, transferred the accumulated water inside the barrier to waste liquidtank by under water pump(*) PCV: Primary containment vessel made of steel
RHR: Residual heat removal system
RHRS: Residual heat removal seawater system
SFP: Spent fuel pool
FPC: Fuel pool cooling system
CST: Condensed water storage tank
SPT: Suppression pool water surge tank
CS: Core spray line
FDW: Feed water line