2. Contain the Spread of Radioactive Substances (sea, soil and atmosphere) The Japanese Government and TEPCO are making the utmost efforts to prevent the dispersion of flow-out radioactive contaminated water. Major Events ・Mar. 27 Stagnant water on the basement floor of the turbine of Unit2 and in the trenches found to be highly contaminated ・Mar. 29 Water in the storage tank started to be transferred to the surge tank, which is the preparation for transfer of stagnant water in the trenches. ・Apr. 1 Highly contaminated water discovered leaking into the sea ・Apr. 6 Leak of contaminated water into the sea was stopped ・Apr. 19 Transfer of stagnant water in the trench of Unit 2 started 19
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2. Contain the Spread of Radioactive Substances(sea, soil and atmosphere)
The Japanese Government and TEPCO are making the utmost efforts to prevent the dispersion
of flow-out radioactive contaminated water.
Major Events・Mar. 27
Stagnant water on the basement
floor of the turbine of Unit2
and in the trenches found
to be highly contaminated
・Mar. 29
Water in the storage tank started to
be transferred to the surge tank, which is
the preparation for transfer of stagnant
water in the trenches.
・Apr. 1
Highly contaminated water
discovered leaking into the sea
・Apr. 6
Leak of contaminated water
into the sea was stopped
・Apr. 19
Transfer of stagnant water in the
trench of Unit 2 started
19
20
Experts are making the utmost efforts to prevent dispersing radioactive substances
contained in dust, debris and vapor.
TEPCO
Spraying synthetic materials on the surface of the ground
and debris to prevent radioactive substances dispersion
2. Contain the Spread of Radioactive Substances(sea, soil and atmosphere)
Step 2Step 1
Mar.11 Apr.17 Around 3 months Around 6~9 months
TargetRadiation dose
in steady decline
Controlling release of
radioactive materials
(significant reduction of dose level)
[Reactors]
[Spent Fuel Pools]
[Contaminated Water]
[Contaminated
Atmosphere/Soil]
Stable cooling - Resume heat exchange function
- [Unit 1,3] flood up to top of active fuel
- [Unit 2] Seal the damaged location
Prevention of spread
Decrease contaminated water(decontamination and desalt)
Install reactor building cover
More stable cooling - Keep sufficient level of water
by remote-control
- Resume heat exchange function
Achieve cold shutdown
Roadmap towards Restoration from the Accident (announced by TEPCO on Apr.17)
21
Stable cooling - Enhance reliability of water injection
- Restore coolant circulation system
- [Unit 4] Install supporting structure
Secure storage place- Prevention of outflow to the outside of the
site
(μSv/h)Explosion in Unit2
White smoke
from Unit3
Grayish smoke from Unit3
Measurement point:
Main Gate (1.0km from Unit2)
or West Gate (1.1km from Unit2)
Monitoring posts and the readings at the
Fukushima Dai-ichi NPS
Near West Gate
21.0 μSv/h
(as of 10:00 April 25th, 2011)
Unit 1~6
Main Gate
53.0 μSv/h
3. Rigorous and Intensive Monitoring
Environmental Radioactivity Level
at the Fukushima Dai-ichi NPS
TEPCO monitors radioactivity levels every 10 minutes and releases the results
immediately. Radioactivity levels rose on March 15th, but have since fallen and
remain low.
TEPCO
2,000
0
12,000
(μSv/h)
4,000
22
Readings at Monitoring Posts out of Fukushima Dai-ichi NPSReadings at Monitoring Posts
out of Fukushima Dai-ichi NPS
23
MEXT, Fukushima Prefectural Government
Fukushima
Dai-ichi
Green box indicates
normal range of
radioactivity
0
5
10
15
20
25
30
13
-Ma
r1
4-M
ar
15
-Ma
r1
6-M
ar
17
-Ma
r1
8-M
ar
19
-Ma
r2
0-M
ar
21
-Ma
r2
2-M
ar
23
-Ma
r2
4-M
ar
25
-Ma
r2
6-M
ar
27
-Ma
r2
8-M
ar
29
-Ma
r3
0-M
ar
31
-Ma
r1
-Ap
r2
-Ap
r3
-Ap
r4
-Ap
r5
-Ap
r6
-Ap
r7
-Ap
r8
-Ap
r9
-Ap
r1
0-A
pr
11
-Ap
r1
2-A
pr
13
-Ap
r1
4-A
pr
15
-Ap
r1
6-A
pr
17
-Ap
r1
8-A
pr
19
-Ap
r
Max.
Min.
(μSv/h)
Fukushima
61km
Atmospheric Readings
0.00
0.10
0.20
0.30
0.40
14
-Ma
r1
5-M
ar
16
-Ma
r1
7-M
ar
18
-Ma
r1
9-M
ar
20
-Ma
r2
1-M
ar
22
-Ma
r2
3-M
ar
24
-Ma
r2
5-M
ar
26
-Ma
r2
7-M
ar
28
-Ma
r2
9-M
ar
30
-Ma
r3
1-M
ar
1-A
pr
2-A
pr
3-A
pr
4-A
pr
5-A
pr
6-A
pr
7-A
pr
8-A
pr
9-A
pr
10
-Ap
r1
1-A
pr
12
-Ap
r1
3-A
pr
14
-Ap
r1
5-A
pr
16
-Ap
r1
7-A
pr
18
-Ap
r1
9-A
pr
Max.
Min.
(μSv/h)
Tokyo
230km
24
MEXT, Fukushima Prefectural Government
Fukushima
Dai-ichi
Green box indicates
normal range of
radioactivity0.00
0.10
0.20
0.30
0.40
14
-Ma
r1
5-M
ar
16
-Ma
r1
7-M
ar
18
-Ma
r1
9-M
ar
20
-Ma
r2
1-M
ar
22
-Ma
r2
3-M
ar
24
-Ma
r2
5-M
ar
26
-Ma
r2
7-M
ar
28
-Ma
r2
9-M
ar
30
-Ma
r3
1-M
ar
1-A
pr
2-A
pr
3-A
pr
4-A
pr
5-A
pr
6-A
pr
7-A
pr
8-A
pr
9-A
pr
10
-Ap
r1
1-A
pr
12
-Ap
r1
3-A
pr
14
-Ap
r1
5-A
pr
16
-Ap
r1
7-A
pr
18
-Ap
r1
9-A
pr
Max.
Min.
(μSv/h)
Hokkaido
630km
Atmospheric Readings
0,00
0,10
0,20
0,30
0,40
17-M
ar
18-M
ar
19-M
ar
20-M
ar
21-M
ar
22-M
ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
1-A
pr
2-A
pr
3-A
pr
4-A
pr
5-A
pr
6-A
pr
7-A
pr
8-A
pr
9-A
pr
10-
Ap
r
11-
Ap
r
12-
Ap
r
Max Min Osaka
580km
25
Instructions (as of 25April 2011)
Tochigi
Fukushima Dai-ichi
Nuclear Power Station
Ibaraki
Fukushima
4. Ensure the Safety of Food, Products, and On-site Workers
Safety of Food
Japan inspects radioactivity in food every day, and restricts distribution of food that fails
to meet provisional regulation values taking into consideration the spread of contamination.
4/13~Sh inch i-mach i, Date-sh i, I itate-mura, Soma-sh i,Minamisoma-sh i, Namie-mach i, Fu taba-mach i,Okuma-mach i, Tomioka-mach i, Naraha-mach i,Hirono-mach i, Kawamata-mach i, Katsu rao-mura,Tamura-sh i, Kawauch i-mu ra
“Shipping advised to comply with relevant NAVAREA warnings off Japan”(News release: March 24)http://www.imo.org/MediaCentre/PressBriefings/Pages/13-navigation-off-japan.aspx
“No Restrictions on Travel to Japan”(News release: March 21)http://www.imo.org/MediaCentre/PressBriefings/Pages/No-restrictions-on-travel-to-Japan.aspx
IAPH(The International Association of Ports and Harbours):“Japanese ports are safe”(News release: March 25) http://www.iaphworldports.org/#
PIANC(The World Association for Waterborne Transport Infrastructure):“No fear on port function and people's health”(News release: April 4)