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Information of Kashiwazaki-Kariwa Nuclear Power Station (The 5th news)
Tokyo Electric Power Company has analyzed seismic observation data, obtained
during the main shock of the recent earthquake.Upon completing the collection andsummarization of all records, we compiled a report (Report 1) outlining the findingsof the study thus far and submitted it to the Nuclear and Industrial Safety Agency on
July 30, while also publicly releasing the information.This report (Report #5)
summarizes and presents the trends identified thus far concerning seismic observation
data.The “relative position of the power station against the epicenter of the main
shock” and “relative positions of reactor units on the power station compound” areshown in Attachment 1 and Attachment 2 respectively.
1. Past developments(1)Public release of seismic observation data recorded by TEPCO at its nuclear power
stationa. On July 16, when the earthquake struck, the maximum acceleration (observationfigures) recorded on the lowest floor (above the mat foundation) of the reactor
buildings at Units 1, 5 and 6 as a bulletin report (interim figures), along with thedesign acceleration response defined for the same locations (design values).
b. After all units completed gathering and summarizing seismic observation
records for the main shock of the earthquake, TEPCO released the observation
figures recorded on the lowest floor (above the mat foundation) of the reactor
buildings at all units, and design values for the same locations as listed below:(Unit: Gal)
Observation figures recorded on
Design values for the samethe lowest floor of the reactor
locationbuilding
Observation
location
NorthNorthEast-west Up-down
East-west Up-downsouthsouth
component component
component component
component
componen
Unit 1311680408274273(235)
Unit 2
304
606
282
167
167(235)
Unit 3
308
384
311
192
193(235)
Unit 4310492337
193
194(235)
Unit 5
277
442
205
249
254(235)
Unit 6
271
322
488
263
263(235)
Unit 7267
356
355263263(235)(Note 1)The figures for Units 1, 5 and 6 are the same as those released on July
16.
(Note 2)The up-down component figures in brackets are used in static design.
(2)Instruction from the Nuclear and Industrial Safety Agency
The observation figures on the lowest floor of the reactor buildings at Units 1, 5and 6 were above the design values based on the standard seismic motion
defined.Based on the finding, the Agency instructed TEPCO to report on thefollowing:a.Analysis of seismic observation data obtained during the recent earthquake
b.Confirmation of seismic safety of important plant facilities in terms of safety
in respect to the recent earthquake

2. TEPCO’s response to NISA’s instruction
In response to the instruction from NISA, received on July 16, TEPCO analyzed
seismic observation data obtained during the main shock of the recent earthquake,compiled the findings thus far into a report (Report #1) and submitted it to NISA
on July 30.The content of the report was also publicly released.
TEPCO will continue to gather and sort records of aftershocks data obtained,and use the information to analyze seismic observation data and confirm the antiquake safety of important facilities in terms of safety.
The outlines of the report are as follows:<Report outlines>(1)Observation records
a. The “acceleration time-history waveform” obtained during the main shock on
the lowest floor of the reactor buildings at Units 1 to 7, and “maximumobserved acceleration and maximum design acceleration response” based on
the waveform, are presented in Attachment 3 and the table below.The
locations of seismometers are as indicated in Attachment 4.
b. The comparison between the “floor response spectrum based on observation
records” observed on the lowest floor of the reactor buildings at Units 1 to 7
and “floor response spectrum calculated based on the Design Basis
Earthquake Ground Motion in the seismic response analysis model used in
the design stage”, are presented in Attachment 3.
These figures may be subject to change according to the future progress ofanalysis and study.
(2)Analysis of seismic observation data
TEPCO will continue to gather and sort aftershock records to conduct
assessment of seismic motions for confirming seismic safety of the power
station in respect to the recent earthquake, and examine seismic motions on thehypothetical free surface of the base stratum on the station premises, with theinfluence of upper strata analytically removed.
(3)Seismic safety confirmation of important facilities in terms of safety
Seismic motion data used for confirming anti-quake safety in respect to therecent earthquake will be used to assess seismic response analysis and antiquake safety assessment on important plant facilities in terms of safety.
(4)Future seismic safety assessment
Based on knowledge obtained from the recent earthquake, including findings
from active fault probes in sea areas and analysis of seismic observation data,
TEPCO will explore future anti-quake safety assessment and items to bereflected to earthquake resistance measures.
(Unit: Gal)
Maximum observed acceleration
figures and design values (Note 1)
Observation location
Remarks
North-south East-west Up-down
component component component
12nd floor
599(460)884(463)394
R1
Reactor5th basement
Unit building
1floor (lowest311(274)680(273)
408
Note 2
1R2floor)
Turbine 1st floor 11862(274) 1459(274)741
Note 3building (pedestal) T2
22nd floor
517(271)718(271)412
R1Reactorbuilding 5th basement 2floor (lowest
304(167)606(167)282
Note 2R2floor)
2Unit
1st floor
431(295)
764(259)594
T1
2
1st floor 2642(588) 1159(478)650
Turbine (pedestal) T2building
3rdbasement 2387(233)
681(232)
470
floor (lowest T3floor)
32nd floor
525(314)650(309)
518
R1Reactor
building 5th basement 3floor (lowest
308(192)384(193)311
Note 2R2floor)Unit
1st floor 33
1350(854) 2058(834)619(pedestal) T1
Turbine3rdbuilding basement 3581(239)549(243)
513
floor (lowest T2floor)2nd floor

4606(299)
R1713(293)

548

Reactorbuilding 5th basement 4floor (lowest310(193)
492(194)
337
Note 2R2floor)
4Unit
1st floor
411(269)560(267)494
T1
4
1st floor 4614(832)763(838)
526
Turbine (pedestal) T2building
3rdbasement 4763(838)442(242)443
floor (lowest T3floor)
53rd floor
472(354)697(350)
331
R1Reactor
4th basement
Unit building
5floor (lowest277(249)442(254)205
Note 25R2floor)
Turbine 2nd floor 51166(995) 1157(754)533
building (pedestal) T2
63rd floor554(415)545(411)578
R1
Unit Reactor
3rd
6 building basement 6271(263)322(263)488
Note 2floor (lowest R2floor)
73rd floor
367(415)435(411)464
R1
Reactor
3rd
building basement 7267(263)356(263)355
Note 2floor (lowest R2floor)
Unit
72nd floor
418(394)506(418)342
7
T1
2nd floor 7673(1096) 1007(859)362
Turbine (pedestal) T2
building
2ndbasement 7318(299)322(312)336
floor (lowest T3floor)(Note 1) The design values are shown in brackets.
(Note 2) As released on July 19(Note 3) This table only shows design values based on dynamic analysis inprinciple (Design values for the up-down component are omitted asthey are based on static design).The design response values (inbrackets) for the first floor of the turbine building at Unit 1 arereference figures based on static design.

3. The Chuetsu-Oki Earthquake Investigation and Countermeasures
Committee concerning Nuclear Power Facilities
The Ministry of Economy, Trade and Industry has set up the Chuetsu-OkiEarthquake Investigation and Countermeasures Committee concerning Nuclear
Power Facilities” to investigate facts regarding specific impact of the Chuetsu-Oki
Earthquake on the Kashiwazaki-Kariwa Nuclear Power Station, and identify futuretasks and responses the government and electric utilities must address in reflectionof the said Earthquake.
On July 31, the Committee convened its first meeting, and agreed to set up
Working Groups to examine specific issues listed below, and deliberate on theirfindings as the main Committee framework.
The in-house fire-fighting corps, information liaison system and thea. mechanism for distributing information to local communities in the event ofan earthquake
Seismic safety assessment based on the knowledge obtained from theb.
Chuetsu-Oki Earthquake
The status of reactor operation management at the time of the Chuetsu-Okic.
Earthquake, integrity of plant facilities and future response
Information contained in this report will be updated as future detailed investigation

by TEPCO makes new findings.
＜References＞ Tokyo Electric Power Company
Nuclear and Industrial Safety Agency
Nuclear Safety Commission of Japan

Japan Nuclear Technology InstituteRev.0
August 1, 2007

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