Nuclear Accident at Fukushima
Daiichi NPP
A collection of images and data
by Toro Laszlo
Member of the Council of the RSRP
National Institute of Public Health
Regional Centre of Public Health
Timisoara
Accident cause
•11/03/2011, 2:46 p.m. local
time (7 hours earlier Romanian
time) near the Japanese island
of Honshu was an earthquake
of 9 on the Richter scale.
•The quake had an impact on
section of north-east coast of
Japan where they are located a
series of nuclear power plants
(NPP).
•Nuclear reactors have been shut
down properly.
NPP DAIICHI before the earthquake
Schema reactorului cu apa in fiebere
al NPP DAIICHI
Remanent heat in DAIICHI NPP
Aszodi, 2011
Event description 12.03.
•
Units 4-6 in shut down status for periodic
maintenance and refuelling
• Units 1-3 were stopped automatically after the quake
• Reactor buildings and the containment successfully
resist to the earthquake
• All reactor were dissconnected from the external AC
supply
• Backup sources (diesel generators) started
• At approximately one hour after the earthquake
tsunami hit the site
– destroyed fuel tanks of the diesel generators
– flooded the diesel generator building
(10m protection wall was not sufficient)
• Mobile generators were sent to the site in a short
time but they ran out of fuel
• Hydrogen Explosion Unit 1
• Evacuation of population from the area of 20km
Daiichi NPP and 10km Daina NPP (approx. 200 000
person
• On-site radioactivity increased
Event description 13.03.
• Lowering the internal
pressure led to hydrogen
explosion at unit 3
• Injection of sea water into the
reactor vessel without
cooling units at unit 1-3
• Variable on-site radioactivity
• Increased radioactivity at
Onagawa NPP (north of
Daiichi) revealed that comes
from Daiichi NPP
Event description 14-15.03.
• Cooling with seawater stopped at Unit 2 (unknown cause),
variable water level in the reactor
• Hydrogen Explosion at Unit 2
• Cooling with sea water stopped at all units due to lack of fule
and water source
• Fire then explosion in the spent fuel storage pool at unit 4
(relatively fresh fuel)
• Restart seawater injection in the reactor wessel at all units
• Significant radioactive emission
• Housing on the area of 20-30 km
• Risk of melting the core and damage of the containment at
Unit 2
Daiichi NPP after hidrogen explosion 15.03.
Daiichi NPP after hidrogen explosion 15.03.
Event description 16.03.
• Fire in spent fuel storage pool at Unit 4, cooling water
evaporation
• Water level decrease at Unit 5, taking water from Unit 6
• Unsuccessfull attempts to feed with cooling water and boric
acid the spent fuel storage pool at Unit 4
• Possible melting (at least partially, 50%) of the core at Units 1
and 3
• Fill with water the reactor vessel of the Unit 2
• Lowering water levels in the spent fuel pool at Units 3 and 4
• Increasing temperature in the spent fuel pool at unit 5 and 6
• Cooling with water canons from the police departement
Daiichi NPP after hidrogen explosion(16.03.)
Event description 17.03.
• Radioactivity observed outside of the site
– Fukushima: 3-170 μSv / h (30 km from the NPP)
– In two places increasing dose 80 to 170, and 26 to 95 μSv/h
– Other directions 1-5 μSv/h
• Begining actions to connect a cable for AC supply to
unit 2
• Continue attempts for cooling Unit 4 with water from
helicopters (without succes) then with water canons
• One of the diesel generators from Unit 6 supplies
Unit 5 for cooling spent fuel storage pool and the
reactor wessel
Event description 18-19.03.
•
•
•
•
•
•
An auxiliary transformer connected to external power source
Actions to connect units 3 and 4 to AC power
Actions to connect units 5 and 6 to AC power
A backup generator from unit 6 repaired
Continue seawater injection into the reactor vessel at Units 1-3
Cooling unit 3 with water canons provided by police and fire departement
units (civil defense, fire rescu units from Tokioand U.S. army), unit 3 is
considered cooling enough
• Considering additional cooling the spent fuel pools from Unit 4
• At 5 AM, 19.03 starting pump C of the shutdown cooling system of unit 3,
used to cool the spent fuel storage pool.
• Restart cooling Unit 4 with water cannons, in collaboration with civil
defense.
Event description 20.03.
• Continue works connect to the power supply
units 3 and 4.
• Continue cooling units 3 and 4with water
cannons
• Continue filling the spent fuel storage pools
• Water injection is continued in reactor vessels
of units 1-3
Event description 20-21.03
•
•
•
•
•
•
•
•
•
•
•
Three holes are driven in the roof of reactor building units 5 and 6 to prevent hydrogen
accumulation
At around 15.55 light gray smoke is observed from the southpart of the 5th floor of
Unit 3
Parameters of the reactor vessel and containment are not change significantly
Increase of radioactivity is subsequently found that returns to lower levels later
For security reasons work is stoped and personnel withdraw from unit 3
Smoke changing color to white and slowly disappears
Ends connecting a cable from the main transformer of the temporary substation.
It begins to restore power supply of units 3, 4, 5 and 6
It restores the power supply from diesel generator of Unit 5
March 21 the presence of radioactivity in seawater is detected near southern discharge
channel near of the Daiichi NPP
Cobalt, iodine and cesium is identified in seawater
Concentration in sea water (Bq/l)
21.mar
22.mar
Co-58
59,5
16,7
I-131
5010
1190
I-132
2100
1360
Cs-134
149
150
Cs-136
213
235
Cs-137
148
153
Event description 22.03.
• Ends cable connecting the power supply to unit 2, the
supply of of the entry side starts
• White smoke seen in Unit 2, until the morning of
22.03 it disappears
• White smoke at unit 3, disappears
• Continue water cooling units 2, 3 and 4, at unit 4 a
concrete pumping device is used to fill the spent fuel
storage pool
• Iodine and cesium is detected in the air at the site
sampling points
Event description 23.03.
• Begins the injection of sea water in unit 2 using the normal cooling system
• Continue injecting sea water into unit 1 and 3
• The power supply of units 1-6 is restored, the main control rooms are
connected to the AC supply
• It began work on restoring power supply of the systems of all units
• Continue injecting seawater in the spent fuel storage pool of units 3 and 4
• At 16.20, 23.03 a gray smoke is observed at unit 3, for security workers
from the control room and around Unit 3 are evacuated
• Smoke changes in white and disappears slowly
• Subsequently found that radioactivity is increasing and decrease more
slowly to the initial values
• End of water feed of the spent fuel storage pool of Unit 4
Green smoke at Unit 3 (23.03.)
Dose rates on the NPP site– sampling point MP6
(μSv/h)
Dose rates on the NPP site– sampling point MP4
(μSv/h)
Dose rates on the NPP site– sampling point MP1
(nSv/h)
Dose rates in Ibaraki prefecture (μSv/h)
7
Dose rate (microSv/h)
6
5
4
3
2
1
0
1
15
29 43
57 71 85
99 113 127 141 155 169 183 197 211 225 239 253 267 281 295 309 323 337 351 365 379 393 407
JAEA NS
JAEA NF
Tokyo University
Dose rates in prefectures (μSv/h)
0,5
0,4
0,3
0,2
Hokkaido(Sappro）
Akita（Akita）
Toshigi（Utsunomiya）
Tokyo（Chinjyuku）
Ichikaw a（kanazaw a）
Gifu（Kakumuhara）
Shiga（Otsu）
nara（Nara）
Okayama（Okayama）
Kagaw a（Takamastu）
Shiga（Shiga）
Miyazaki（Miyazaki）
Aomori（Aomori）
Yamagata（Yamagata）
Gunma（Maebashi）
kanagaw a（Chigasaki）
Fukui（Fukui）
Shizuoka（Shizuoka）
Kyoto（Kyoto）
Wakayama（Wakayama）
Hiroshima（Hiroshima）
Ehime（Matsuyama）
Nagasaki（Ohmura）
Kagoshima（Kagoshima）
Iw ate（Morioka）
Fukushima（Futaba）
Saitama（Saitama）
Niigata（Niigata）
Yamanashi（Kohu）
Aichi（Nagoya）
Osaka（Osaka）
Tottori（Tohhaku）
Yamaguchi（Yamaguchi）
Kochi（Kochi）
Kumamoto（Uto）
Okinaw a（Uruma）
10_11
3_4
20-21
13-14
6_7
23-24
16-17
9_10
2_3
19-20
12_13
5_6
22-23
15-16
8_9
1_2
18-19
11_12
4_5
21-22
14-15
7_8
0
0-1
0,1
17-18
Dose rate (microSv/h)
0,6
MIyagi（Sendai）
Ibaraki（Mito）
Chiba（Ishihara）
Toyama（Imizu）
Nagano（Nagano）
Mie（Yokkaichi）
Hyogo（Kobe）
Shimane（Matsue）
Tokushima（Tokushima
Fukuoka（Dazaifu）
Oita（Oita）
Drinking water (mBq/kg)
I-131 and Cs-137 in tape water (mBq/kg)
100000
10000
1000
100
10
1
18.03.2011
Hokkaido I-131
Aomori Cs-137
Miyagi I-131
Akita Cs-137
Fukushima I-131
Ibaraki Cs-137
Gunma I-131
Saitama Cs-137
Tokyo I-131
Kanagaw a Cs-137
Toyama I-131
Ishikaw a Cs-137
Yamanashi I-131
Nagano Cs-137
Shizuoka I-131
Aichi Cs-137
Shiga I-131
Kyoto Cs-137
19.03.2011
20.03.2011
Hokkaido Cs-137
Iw ate I-131
Miyagi Cs-137
Yamagata I-131
Fukushima Cs-137
Tochigi I-131
Gunma Cs-137
Chiba I-131
Tokyo Cs-137
Niigata I-131
Toyama Cs-137
Fukui I-131
Yamanashi Cs-137
Gifu I-131
Shizuoka
Mie I-131
Shiga Cs-137
Osaka I-131
21.03.2011
Aomori I-131
Iw ate Cs-137
Akita I-131
Yamagata Cs-137
Ibaraki I-131
Tochigi Cs-137
Saitama I-131
Chiba Cs-137
Kanagaw a I-131
Niigata Cs-137
Ishikaw a I-131
Fukui Cs-137
Nagano I-131
Gifu Cs-137
Aichi I-131
Mie Cs-137
Kyoto I-131
Osaka Cs-137
fall out (kBq/m2 )
Fall out (kBq/m2)
100,00
80,00
60,00
40,00
20,00
0,00
18.08-19.03
19.08-20.03
20.08-21.03
21.08-22.03
22.08-23.03
Hokkaido I-131
Hokkaido Cs-137
Aomori I-131
Aomori Cs-137
Iw ate I-131
Iw ate Cs-137
Miyagi I-131
Miyagi Cs-137
Akita I-131
Akita Cs-137
Yamagata I-131
Yamagata Cs-137
Fukushima I-131
Fukushima Cs-137
Ibaraki I-131
Ibaraki Cs-137
Tochigi I-131
Tochigi Cs-137
Gunma I-131
Gunma Cs-137
Saitama I-131
Saitama Cs-137
Chiba I-131
Chiba Cs-137
Tokyo I-131
Tokyo Cs-137
Kanagaw a I-131
Kanagaw a Cs-137
Niigata I-131
Niigata Cs-137
Toyama I-131
Toyama Cs-137
Ishikaw a I-131
Ishikaw a Cs-137
Fukui I-131
Fukui Cs-137
Yamanashi I-131
Yamanashi Cs-137
Nagano I-131
Nagano Cs-137
Gifu I-131
Gifu Cs-137
Shizuoka I-131
Shizuoka
Aichi I-131
Aichi Cs-137
Mie I-131
Mie Cs-137
Shiga I-131
Shiga Cs-137
Kyoto I-131
Kyoto Cs-137
Osaka I-131
Osaka Cs-137
Hyogo I-131
Hyogo Cs-137
Nara I-131
Nara Cs-137
Wakayama I-131
Wakayama Cs-137
Tottori I-131
Tottori Cs-137
Shimane I-131
Shimane Cs-137
Okayama I-131
Okayama Cs-137
Hiroshima I-131
Hiroshima Cs-137
Yamaguchi I-131
Yamaguchi Cs-137
Tokushima I-131
Tokushima Cs-137
Kagaw a I-131
Kagaw a Cs-137
Ehime I-131
Ehime Cs-137
Kochi I-131
Kochi Cs-137
Fukuoka I-131
Fukuoka Cs-137
Shiga I-131
Shiga Cs-137
Nagasaki I-131
Nagasaki Cs-137
Possible dispersion of the cloud
Dose rates on the NPP site
Romanian situation
• Radioactive cloud will not reach or will reach a very low concentration (m
or μBq/m3) due to long distance (high dilution)
• From the event will not result a Chernobyl type contamination:
– Much lower emission time and intensity
– Emission composition totally different, less a few orders of magnitude
– Much greater distance
• There is a "crisis cell" at the regulator, CNCAN
• Press release on the website of the Ministry of Health and the Romanian
Society of Radioprotection
• The population is warning:
– Stable iodine administration is not necessary
– Risks of stable iodine administration without medical suprevision
• There are no radiological risk for potential tourists to the Far East
• Urgent measures are not necessary
Daiichi NPP one minute before explosion at Unit 3
Daiichi NPP three minutes after explosion at Unit 3
Infrared photos of Daiichi NPP