The Tokyo Electric Power Company, Inc. (TEPCO) has been conducting internal
inspection based on the order given from the Nuclear and Industrial Safety
Agency (NISA). Today, we submitted our inspection report to the NISA.
The three items included in the orders from the NISA and summary of our response
is as follows:
[Order Item 1]
Inspect the cause of delay in reporting the leakage of water containing
[Summary of Cause and Measures to be Taken]
a. Absence of technical staff for radiation measurement due to evacuation order
given in the plant.
--> Consider a system in which other staffs can execute radiation measurements
in case of an emergency.
b. Delay in measuring radioactivity in suspected water source.
--> Consider procedure in case radioactivity is identified in uncontrolled areas.
[Order Item 2]
Reflect on TEPCO's response regarding the Unit 3 house transformer fire.
[Summary of Issues and Measures to be Taken]
a. Delay in calling the fire department due to telephone line congestion.
--> Consider means to secure communication channels with the fire department
including a hot-line system.
b. Insufficient in-house fire fighting due to damages in outdoor fire hydrants.
--> Reinforce the in-house fire fighting team to better prepare for initial fire
fighting activities; rent chemical fire engines from thermal power stations.
[Order Item 3] Analyze the seismic data of the Niigata-Chuetsu-Oki earthquake
and confirm the seismic safety of safety-related facilities.
a. Collection and Analyses of Seismic Data
--> We have collected and sorted data for the main quake from seismographs
installed in all seven units at the station. We will continue collecting and
sorting data for the aftershocks and subsequently analyze all observed data.
--> During the course of data collection following the earthquake, we confirmed
that among the seismic data collected from the 63 existing seismographs, seismic
wave profile data had disappeared. However, we believe sufficient analyses will
be possible based on maximum acceleration data found in the existing seismographs
for the main quake; all data for the main quake is available from the newly
installed seismographs for all units, and subsequent data for the aftershocks
are available from both existing and newly installed seismographs.
b. Confirmation of the Seismic Safety of Safety-Related Facilities
--> We will conduct seismic response analyses and seismic safety evaluation for
safety-related facilities based on seismic data obtained from the above-mentioned
data collection and analyses.
In consideration of issues identified in this report, we will immediately consider
recurrence prevention measures and make every effort to secure safety of the station.