Ministry of Economy, Trade and Industry, Government of Japan On the Upgrading of Japanese Examination Guide for Aseismic Design of Nuclear Power Reactor Facilities Shuji Kawahara and Kenji Takashima
Ministry of Economy, Trade and Industry, Government of Japan
On the Upgrading of JapaneseExamination Guide for Aseismic Design of
Nuclear Power Reactor Facilities
Shuji Kawahara and Kenji Takashima
Ministry of Economy, Trade and Industry, Government of Japan
Contents of the Presentation1. Upgrading of Japanese Examination Guide for
Aseismic Design of Nuclear Power Reactor Facilities
2. A Methodology to Determine Design EarthquakeGround Motion Which Might Occur in the Hidden Seismic Source
3. Short Report of EQ. Observation at Reactor Bldg.s in Kashiwazaki-Kariwa Nuclear Power Station
Ministry of Economy, Trade and Industry, Government of Japan
Upgrading of the Aseismic Design Examination Guide
- Japanese “Examination Guide for Aseismic Design of Nuclear Power Reactor Facilities” had established over 20 years ago
- The Examination Guide is now under the process of upgrading by the Nuclear Safety Commission of Japan.
- The major points of the discussion on upgrading are:1) The fundamental way of thinking about the safety
evaluation of the seismic design.2) Classification of seismic safety importance.3) Earthquake ground motion for seismic design.4) Evaluation of the seismic safety of the facilities.
- The works and discussions are currently still on going.
Ministry of Economy, Trade and Industry, Government of Japan
Classification of Seismic Safety Importance
Class Structure System and Component (SSC) Design Load
I
SSCs having radioactive materials inside SSCs directly related to other SSCs of aboveSSCs needed to avoid radioactive material release SSCs needed to shutdown the reactorSSC needed to reduce an influence by theradioactive material release in the atmosphere
Design Earthquake of Ss(Static seismic load of 3.0CI ?)
II SSCs whose influence and effect is small as compare to the the seismic class I.
Static seismic load of 1.5CI
III SSCs other than the seismic classes of I and IIStatic seismic load of 1.0CI
For upgrading, the classes A and As are proposed to be integrated
Ministry of Economy, Trade and Industry, Government of Japan
The earthquake ground motion Ss is proposed1) Take into account the past earthquake ground motion and
ground motion caused by active faults. “Seismo-techtonic” knowledge is also considered for reference.
2) Consider the earthquake ground motion presumed without specifying the seismic sources based on a probabilistic study and/or past earthquake records obtained in the neighborhood of epicenters without seismic fault in the inland cluster earthquakes.
3) Check the probability of the ground motion level of Ss afterdesign.
4) Earthquake ground motion in the vertical direction at free field be also determined.
The Ss design earthquake is based on the concept of S2
Ministry of Economy, Trade and Industry, Government of Japan
Earthquake Ground Motion for Seismic Design- Consideration of the EQ Ground Motion due to Hidden Fault -
Period (sec)Period (sec)
EQ Ground MotionShould be Considered at LeastTypical EQs Due to
Hidden Fault Worldwide
Ground Motion Records of 6 EQs
Period (sec)
Seismic Bedrock
Hor. Motion
Period (sec)
Seismic Bedrock
Hor. Motion
Period (sec)
Seismic Bedrock
Hor. Motion
Period (sec)
Seismic Bedrock
Hor. Motion
Period (sec)Period (sec)
Seismic Hazard SpectraAnnual Exceedance Prov.
10-310-4
10-5
Period (sec)Period (sec)Period (sec)Period (sec)
Seismic Hazard SpectraAnnual Exceedance Prob.
10-310-4
10-5
Probabilistic EQ HazardAnalysis with Fault
Model for NFE(Mj=6, 6.6, 6.8, 7.3)
The Spectrum is Corresponding toAnnual Exceedance Prob. of 10-4
Ministry of Economy, Trade and Industry, Government of Japan
List of Earthquakes Whose Seismic Sources are not Found Clearly
The 1991 Sierra Madre Earthquake, Mw:5.6The 1978 Santa Barbara Earthquake, Mw:5.8The 1979 Coyote Lake Earthquake, Mw:5.8The 1987 Whittier Narrow Earthquake, Mw:6.0The 1984 Nagano-ken Seibu Earthquake, Mw:6.1The 1984 Morgan Hill Earthquake, Mw:6.2
Ministry of Economy, Trade and Industry, Government of Japan
Current Status of Upgrading of the Examination Guide
Preparation Works are in the Final Stage,However, Discussions are Still on-going
In Particular in Handling of the Methodology for Evaluating Seismic Safety of the Facilities.
Ministry of Economy, Trade and Industry, Government of Japan
EQ Observation at Reactor Bldg.s in an NPS during 2004 Niigata-ken Chuetsu EQ on an NPS
Kashiwazaki-Kariwa Nuclear Power Station (7 Units)
Ministry of Economy, Trade and Industry, Government of Japan
Relationship b/w Observed EQ Ground Motion & Design EQ., S1
Veloc
ity (c
m/sec
)
Design EQ GM of S1
Niigata EQ, Mj6.8, 22km
Period (sec)Six Units Had been Kept Operating w/o Any Problem, One Unit was Under Periodical Inspection
Mw:6.6
Ministry of Economy, Trade and Industry, Government of Japan
Observed Acceleration at Unit 5 Reactor Building
26.7Gal., 58.5Gal., 55.9Gal.
42.8Gal.,79.9Gal., 57.9Gal.
52.8Gal., 95.2Gal., 58.1Gal.
75.2Gal., 267.4Gal., 221.5Gal.
83m
75m
Ministry of Economy, Trade and Industry, Government of Japan
Observed Acceleration at Unit 6 Reactor Building
33.9Gal., 58.5Gal., 67.8Gal.
42.6Gal.,63.4Gal., No Obs.
73.7Gal., 83.9Gal., 80.0Gal.
139.6Gal., 118.4Gal., 110.7Gal.
At Free Field
(-2.7m)
78.8Gal.131.8Gal.59.7Gal.
Ministry of Economy, Trade and Industry, Government of Japan
Incidental Event (Nov. 4, 2004)The Unit 7 Had Tripped by the After Shock (Mj: 5.2, Depth: 18km) in the Morning of Nov. 4, 2004 due to the Signal of Turbine Axis Displ. in the Thrust Bearing Exceeding the Trip Level.After the Trip the Plant was Inspected and Found No Damage.
Then the Plant HadBeen Restarted 7days after the Trip.
Thrust Bearing Coupling
Hi-pressure Turbine Rotor Low-pressure Turbine Rotor
3 Gap Sensors
Ministry of Economy, Trade and Industry, Government of Japan
The End
Thank You