On April 4th, 2011, we reported on the preventive measures to be taken
after receiving severe warning from Nuclear and Industrial Safety Agency
(NISA) on April 1st in regard to the results on nuclide analysis at
Fukushima Daiichi Nuclear Power Station.
                                 (Previously announced on April 4th, 2011)

Accordingly, we would like to inform the results of re-evaluation on
nuclide analysis in regard to samples collected before March 30th from
accumulated water in the turbine building, water in the trench and
sub-drain (subsurface water) near the turbine building, together with
accumulated water detected in the Process Main Building of Centralized
Radiation Waste Treatment Facility. The re-valuation was conducted in
accordance with the preventive measures.

The preventive measures are as follows and re-valuation was conducted
based on such measures.

<Preventive measures>
1.Evaluation of nuclide analysis based on experts' opinion
  Experts from third-party institution verified the concept of nuclide
  identification and evaluation was conducted after reflecting such
  experts' opinions.

2.Deliberation on the method of cross-check
  Experts from manufacturer confirmed the adequacy of nuclide library in
  the analytical equipment. In addition, experts from third-party
  institution confirmed the adequacy of concept in regard to program used
  for nuclide analysis evaluation.

3.Improvement of accuracy achieved by support from other institutions,
  such as electric utilities
  We attempted to improve the accuracy of nuclide analysis evaluation by
  asking other electric utilities and third-party institutions for support
  on reviewing data and adequacy.

4.Preparation of preliminary report and definite report
  In order to achieve good balance between accuracy and promptness, we
  made announcement in 2 stages. Firstly, we released a preliminary
  report (determination of radioactivity density regarding the 3 major
  nuclides, while providing them as reference data in the results of
  nuclide analysis) and thereafter a definite report (determination and
  announcement of radioactivity density regarding major nuclides as well
  as other nuclides).
                                (Previously announced on April 20th, 2011)

We would like to inform the results of re-evaluation, confirmed in
accordance with the preventive measures, on nuclide analysis in regard to
the samples collected during the period of April 24th to May 7th from the
air at the site of power station, seawater near the power station, seawater
near the shallow draft quay and in front of bar screen of Unit 2,
sub-drain water near the turbine buildings, sub-drain water near
Centralized Radiation Waste Treatment Facility, and sea-bottom soil
around the power station and in front of the shallow draft quay.

We will inform the results of re-evaluation on nuclide analysis in regard
to the samples collected after May 8th from the air at the site of power
station and seawater near the power station, after confirming them in
accordance with the preventive measures.

Appendix1: [Definite Report] Result of Nuclide Analysis of Radioactive 
           Materials in the Air at the Site of Fukushima Nuclear Power 
           Stations (PDF 43.4KB) 
Appendix2: [Definite Report] Results of Nuclide Analysis of Seawater 
                                                              (PDF 202KB) 
Appendix3: [Definite Report] Result of Nuclide Analysis of Seawater at 
           Fukushima Daiichi NPS Shallow Draft Quay、Unit 2 screen, and 
                          the water intake canal of Units 1-4 (PDF 49.9KB) 
Appendix4: [Definite Report] Result of Nuclide Analysis of Sub-drains, 
           Fukushima Daiichi NPS (PDF 41.8KB) 
Appendix5: [Definite Report] Fukushima Daiichi Results of nuclide analysis 
           of accumulated water in the Process Main Building of 
           Centralized Radiation Waste Treatment Facility (PDF 31.5KB) 
Appendix6: [Definite Report] Fukushima Daiichi Results of nuclide analysis 
           of sea-bottom soil (PDF 8.98KB)