damaged by the earthquake and the subsequent tsunami 
on 11 March 2011
 
Compilation by GRS
as at 15 April 2011, 12:30 h (CEST)
All times local time (JST) unless otherwise indicated
(CET (until 26-03-2011) = JST minus 8 hours)
(CEST (since 27-03-2011) = JST minus 7 hours)
Updated compilation of information   
Short description of measures for stabilisation of the plant  and measures for retaining
of the contamination or avoidance of its distribution contamination at Fukushima Dai-
ichi is given in Chapter 3.
1  Changes compared with the previous state
1.1  Fukushima Dai-ichi
Floating barriers for retaining of possible radioactive suspended substances were ar-
ranged in the sea water at the coolant water intake of Units 1 through 4 in the northern
and southern port areas. According to JAIF, works for further earthquake and tsunami
management were carried out. Emergency generators, vehicles with emergency die-
sels and fire fighting equipment were dislocated to a higher-level area of the site. The
emergency power supply shall be improved by re-establishing of the grid connection, i.
e. new cable routes.
1.1.1  Unit 1
No change.
1.1.2  Unit 2
No change.
 
1.1.3  Unit 3 
On 14-04-2011 from 15:56 h until 16:32 h, coolant was injected into the fuel pool of
Unit 3 by means of a truck-mounted concrete pump. 
1.1.4  Unit 4 
A nuclide analysis of the samples from the fuel pool of Unit 4 on 12-04-2011 was re-
ported by TEPCO (caesium-134: 88 Bq/cm3, caesium-137: 93 Bq/cm3, iodine-131: 220
Bq/cm3, as compared to the sample of 04-03-2011: caesium-134: below detection lev-
el, caesium 137: 0,13 Bq/cm3, iodine 131: below detection level). According to KYODO,
TEPCO reported that the nuclide analysis confirmed the assumption of the fuel dam-
age in the fuel pool. The scope of damage was estimated as low. ThEPCO does not
rule out, that a part of the fuel damage might have been caused by debries that fell into
the fuel pool.   
1.1.5  Units 5 and 6
No change.
1.1.6  Interim storage facility at the Fukushima Dai-ichi site
No change.
1.2  Fukushima Dai-ni
No change.
1.3  Onagawa 1-3 
No change.
1.4  Tokai and Higashidori
No change.
2  Radiological situation
2.1  Radiological situation 
Radiological situation at the site
The local dose rates were available on 15-04-2011 until 15:00 h. The measurement
values  for  the  measuring  location  ,south  front  central  building“  dropped  again  to
530 μSv/h. The measurement readings for other measuring locations remain constant
or show a slightly decreasing trend. 
Fig. 1.1 Local dose rate on 14-04-2011
Sea contamination
Contamination values for the sea water are available of the status until 13-04-2011, (for
diagrams s. German report, Section 2.3). The measurement readings reveal contami-
nation in particular for iodine-131 well above the limiting values.
FigFehler! Verweisquelle konnte nicht gefunden werden. page Fehler! Textmarke
nicht definiert. (German report) shows the measuring locations in graphs.
 Radiological situation in the vicinity
The local dose rate measurement readings in the selected prefectures – like in the pre-
vious days – remain constant or decrease on for the prefectures Ibaraki and Kanaga-
wa.
The prefecture Fukushima released measurement values of the local dose rate for res-
idential areas Fukushima City, Koriyama, Shirakawa, Wakamatsu, Minami Aizu, Soma,
Iwaki, IItata and Tamura of 15-04-2011. The distance of the measurement locations to
Fukushima Dai-ichi is from 24 km (Soma City) and 115 km (Minami Aizu). The local
dose measurement readings were between 0.08 for Minami and 5.26 μSv/h for IItate.
Since the Japanese authority specifies the values of 0.02 to 0.05 μSv/h as natural
background, the measured local dose rate exceed them by 10 times at an average,
that for Koriyama by 30 times and that for Fukushima City by 40 times. No background
was specified for IItate. 
External AM
FigFehler! Verweisquelle konnte nicht gefunden werden., page Fehler! Textmarke
nicht definiert. (German report) shows the evacuation areas in graphs.
Measures to retain or avoid spread of contamination.
?Almost daily tests to spray resin near the common interim storage facility in the area
of about 500 m2 to 1600 m2. Resin should bind particles to prevent re-suspension
of radioactivity. 
?Floating barriers for retaining of contaminated suspended substances at the coolant
water intake of Units 1 through 4 in the site port. 
?Employment of metal plates for sealing of coolant water intake of Unit 2